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[Git][ghc/ghc][wip/marge_bot_batch_merge_job] 4 commits: rts: avoid Cmm loop to initialize Array#/SmallArray#
by Marge Bot (＠marge-bot) 22 Jan '26

22 Jan '26

Marge Bot pushed to branch wip/marge_bot_batch_merge_job at Glasgow Haskell Compiler / GHC Commits: cdb74049 by Cheng Shao at 2026-01-22T14:52:36-05:00 rts: avoid Cmm loop to initialize Array#/SmallArray# Previously, `newArray#`/`newSmallArray#` called an RTS C function to allocate the `Array#`/`SmallArray#`, then used a Cmm loop to initialize the elements. Cmm doesn't have native for-loop so the code is a bit awkward, and it's less efficient than a C loop, since the C compiler can effectively vectorize the loop with optimizations. So this patch moves the loop that initializes the elements to the C side. `allocateMutArrPtrs`/`allocateSmallMutArrPtrs` now takes a new `init` argument and initializes the elements if `init` is non-NULL. - - - - - 4c784f00 by Cheng Shao at 2026-01-22T14:53:19-05:00 Fix testsuite run for +ipe flavour transformer This patch makes the +ipe flavour transformer pass the entire testsuite: - An RTS debug option `-DI` is added, the IPE trace information is now only printed with `-DI`. The test cases that do require IPE trace are now run with `-DI`. - The testsuite config option `ghc_with_ipe` is added, enabled when running the testsuite with `+ipe`, which skips a few tests that are sensitive to eventlog output, allocation patterns etc that can fail under `+ipe`. This is the first step towards #26799. Co-authored-by: Codex <codex(a)openai.com> - - - - - 33c700f6 by Ben Gamari at 2026-01-22T15:26:06-05:00 hadrian: Bump QuickCheck upper bound This patch bumps QuickCheck upper bound to 2.18. selftest rule manually tested to work with current latest QuickCheck-2.17.1.0. - - - - - b1a60194 by Zubin Duggal at 2026-01-22T15:26:12-05:00 Add genindex to index.rst. This adds a link to the index in the navigation bar. Fixes #26437 - - - - - 21 changed files: - docs/users_guide/index.rst - docs/users_guide/runtime_control.rst - hadrian/hadrian.cabal - hadrian/src/Flavour.hs - libraries/ghc-compact/tests/all.T - libraries/ghc-internal/tests/backtraces/all.T - rts/AllocArray.c - rts/AllocArray.h - rts/ClosureTable.c - rts/Heap.c - rts/PrimOps.cmm - rts/RtsFlags.c - rts/Threads.c - rts/Trace.c - rts/Weak.c - rts/include/rts/Flags.h - testsuite/driver/testglobals.py - testsuite/driver/testlib.py - testsuite/tests/rts/Makefile - testsuite/tests/rts/all.T - testsuite/tests/rts/ipe/all.T Changes: ===================================== docs/users_guide/index.rst ===================================== @@ -29,6 +29,7 @@ Contents: eventlog-formats glossary editing-guide + genindex Indices and tables ===================================== docs/users_guide/runtime_control.rst ===================================== @@ -1588,6 +1588,7 @@ recommended for everyday use! .. rts-flag:: -Ds DEBUG: scheduler .. rts-flag:: -Di DEBUG: interpreter +.. rts-flag:: -DI DEBUG: IPE .. rts-flag:: -Dw DEBUG: weak .. rts-flag:: -DG DEBUG: gccafs .. rts-flag:: -Dg DEBUG: gc ===================================== hadrian/hadrian.cabal ===================================== @@ -190,4 +190,4 @@ executable hadrian if flag(selftest) other-modules: Rules.Selftest cpp-options: -DHADRIAN_ENABLE_SELFTEST - build-depends: QuickCheck >= 2.6 && < 2.15 + build-depends: QuickCheck >= 2.6 && < 2.18 ===================================== hadrian/src/Flavour.hs ===================================== @@ -384,9 +384,15 @@ omitPragmas = addArgs -- | Build stage2 dependencies with options to enable IPE debugging -- information. enableIPE :: Flavour -> Flavour -enableIPE = addArgs - $ notStage0 ? builder (Ghc CompileHs) - ? pure ["-finfo-table-map", "-fdistinct-constructor-tables"] +enableIPE = + addArgs $ + mconcat + [ notStage0 + ? builder (Ghc CompileHs) + ? pure + ["-finfo-table-map", "-fdistinct-constructor-tables"], + builder Testsuite ? arg "--config=ghc_with_ipe=True" + ] enableLateCCS :: Flavour -> Flavour enableLateCCS = addArgs ===================================== libraries/ghc-compact/tests/all.T ===================================== @@ -20,7 +20,8 @@ test('compact_gc', [fragile_for(17253, ['ghci']), ignore_stdout], compile_and_ru # this test computes closure sizes and those are affected # by the ghci and prof ways, because of BCOs and profiling headers. # Optimization levels slightly change what is/isn't shared so only run in normal mode -test('compact_share', only_ways(['normal']), compile_and_run, ['']) +test('compact_share', [only_ways(['normal']), when(ghc_with_ipe(), skip)], # IPE changes allocation/layout affecting compactSize output. + compile_and_run, ['']) test('compact_bench', [ ignore_stdout, extra_run_opts('100') ], compile_and_run, ['']) test('T17044', normal, compile_and_run, ['']) ===================================== libraries/ghc-internal/tests/backtraces/all.T ===================================== @@ -2,5 +2,5 @@ test('T14532a', [], compile_and_run, ['']) test('T14532b', [], compile_and_run, ['']) test('T26507', [ when(have_profiling(), extra_ways(['prof'])) , when(js_arch(), skip) - , exit_code(1)], compile_and_run, ['']) - + , when(ghc_with_ipe(), skip) # IPE builds include an IPE backtrace section on stderr. + , exit_code(1)], compile_and_run, ['']) ===================================== rts/AllocArray.c ===================================== @@ -5,6 +5,7 @@ StgMutArrPtrs *allocateMutArrPtrs (Capability *cap, StgWord nelements, + StgClosure *init, CostCentreStack *ccs USED_IF_PROFILING) { /* All sizes in words */ @@ -25,6 +26,12 @@ StgMutArrPtrs *allocateMutArrPtrs (Capability *cap, arr->ptrs = nelements; arr->size = arrsize; + if (init != NULL) { + for (StgWord i = 0; i < nelements; ++i) { + arr->payload[i] = init; + } + } + /* Initialize the card array. Note that memset needs sizes in bytes. */ memset(&(arr->payload[nelements]), 0, mutArrPtrsCards(nelements)); @@ -33,6 +40,7 @@ StgMutArrPtrs *allocateMutArrPtrs (Capability *cap, StgSmallMutArrPtrs *allocateSmallMutArrPtrs (Capability *cap, StgWord nelements, + StgClosure *init, CostCentreStack *ccs USED_IF_PROFILING) { @@ -47,6 +55,13 @@ StgSmallMutArrPtrs *allocateSmallMutArrPtrs (Capability *cap, /* No write barrier needed since this is a new allocation. */ SET_HDR(arr, &stg_SMALL_MUT_ARR_PTRS_DIRTY_info, ccs); arr->ptrs = nelements; + + if (init != NULL) { + for (StgWord i = 0; i < nelements; ++i) { + arr->payload[i] = init; + } + } + return arr; } ===================================== rts/AllocArray.h ===================================== @@ -21,16 +21,19 @@ */ /* Allocate a StgMutArrPtrs for a given number of elements. It is allocated in - * the DIRTY state. + * the DIRTY state. If init is non-NULL, initialize payload elements to init. */ StgMutArrPtrs *allocateMutArrPtrs (Capability *cap, StgWord nelements, + StgClosure *init, CostCentreStack *ccs); -/* Allocate a StgSmallMutArrPtrs for a given number of elements. +/* Allocate a StgSmallMutArrPtrs for a given number of elements. If init is + * non-NULL, initialize payload elements to init. */ StgSmallMutArrPtrs *allocateSmallMutArrPtrs (Capability *cap, StgWord nelements, + StgClosure *init, CostCentreStack *ccs); /* Allocate a StgArrBytes for a given number of bytes. ===================================== rts/ClosureTable.c ===================================== @@ -46,7 +46,7 @@ bool enlargeClosureTable(Capability *cap, ClosureTable *t, int newcapacity) ASSERT(newcapacity > oldcapacity); StgMutArrPtrs *newarr; - newarr = allocateMutArrPtrs(cap, newcapacity, CCS_SYSTEM_OR_NULL); + newarr = allocateMutArrPtrs(cap, newcapacity, NULL, CCS_SYSTEM_OR_NULL); if (RTS_UNLIKELY(newarr == NULL)) return false; StgArrBytes *newfree; @@ -276,4 +276,3 @@ static bool isCompactClosureTable(ClosureTable *t) } return isCompact; } - ===================================== rts/Heap.c ===================================== @@ -279,7 +279,7 @@ StgMutArrPtrs *heap_view_closurePtrs(Capability *cap, StgClosure *closure) { StgClosure **ptrs = (StgClosure **) stgMallocBytes(sizeof(StgClosure *) * size, "heap_view_closurePtrs"); StgWord nptrs = collect_pointers(closure, ptrs); - StgMutArrPtrs *arr = allocateMutArrPtrs(cap, nptrs, cap->r.rCCCS); + StgMutArrPtrs *arr = allocateMutArrPtrs(cap, nptrs, NULL, cap->r.rCCCS); if (RTS_UNLIKELY(arr == NULL)) goto end; SET_INFO((StgClosure *) arr, &stg_MUT_ARR_PTRS_FROZEN_CLEAN_info); ===================================== rts/PrimOps.cmm ===================================== @@ -386,24 +386,11 @@ stg_newArrayzh ( W_ n /* words */, gcptr init ) again: MAYBE_GC(again); - ("ptr" arr) = ccall allocateMutArrPtrs(MyCapability() "ptr", n, CCCS); + ("ptr" arr) = ccall allocateMutArrPtrs(MyCapability() "ptr", n, init "ptr", CCCS); if (arr == NULL) (likely: False) { jump stg_raisezh(HsIface_heapOverflow_closure(W_[ghc_hs_iface])); } - // Initialise all elements of the array with the value init - W_ p; - p = arr + SIZEOF_StgMutArrPtrs; - // Avoid the shift for `WDS(n)` in the inner loop - W_ limit; - limit = arr + SIZEOF_StgMutArrPtrs + WDS(n); - for: - if (p < limit) (likely: True) { - W_[p] = init; - p = p + WDS(1); - goto for; - } - return (arr); } @@ -496,24 +483,11 @@ stg_newSmallArrayzh ( W_ n /* words */, gcptr init ) again: MAYBE_GC(again); - ("ptr" arr) = ccall allocateSmallMutArrPtrs(MyCapability() "ptr", n, CCCS); + ("ptr" arr) = ccall allocateSmallMutArrPtrs(MyCapability() "ptr", n, init "ptr", CCCS); if (arr == NULL) (likely: False) { jump stg_raisezh(HsIface_heapOverflow_closure(W_[ghc_hs_iface])); } - // Initialise all elements of the array with the value init - W_ p; - p = arr + SIZEOF_StgSmallMutArrPtrs; - // Avoid the shift for `WDS(n)` in the inner loop - W_ limit; - limit = arr + SIZEOF_StgSmallMutArrPtrs + WDS(n); - for: - if (p < limit) (likely: True) { - W_[p] = init; - p = p + WDS(1); - goto for; - } - return (arr); } ===================================== rts/RtsFlags.c ===================================== @@ -209,6 +209,8 @@ void initRtsFlagsDefaults(void) RtsFlags.DebugFlags.numa = false; RtsFlags.DebugFlags.compact = false; RtsFlags.DebugFlags.continuation = false; + RtsFlags.DebugFlags.iomanager = false; + RtsFlags.DebugFlags.ipe = false; #if defined(PROFILING) RtsFlags.CcFlags.doCostCentres = COST_CENTRES_NONE; @@ -482,6 +484,7 @@ usage_text[] = { #if defined(DEBUG) " -Ds DEBUG: scheduler", " -Di DEBUG: interpreter", +" -DI DEBUG: IPE", " -Dw DEBUG: weak", " -DG DEBUG: gccafs", " -Dg DEBUG: gc", @@ -2311,6 +2314,9 @@ static void read_debug_flags(const char* arg) case 'o': RtsFlags.DebugFlags.iomanager = true; break; + case 'I': + RtsFlags.DebugFlags.ipe = true; + break; default: bad_option( arg ); } ===================================== rts/Threads.c ===================================== @@ -894,7 +894,7 @@ StgMutArrPtrs *listThreads(Capability *cap) } // Allocate a suitably-sized array... - StgMutArrPtrs *arr = allocateMutArrPtrs(cap, n_threads, cap->r.rCCCS); + StgMutArrPtrs *arr = allocateMutArrPtrs(cap, n_threads, NULL, cap->r.rCCCS); if (RTS_UNLIKELY(arr == NULL)) goto end; // Populate it... ===================================== rts/Trace.c ===================================== @@ -685,7 +685,8 @@ void traceHeapProfSampleString(const char *label, StgWord residency) void traceIPE(const InfoProvEnt *ipe) { #if defined(DEBUG) - if (RtsFlags.TraceFlags.tracing == TRACE_STDERR) { + if (RtsFlags.TraceFlags.tracing == TRACE_STDERR + && RtsFlags.DebugFlags.ipe) { ACQUIRE_LOCK(&trace_utx); char closure_desc_buf[CLOSURE_DESC_BUFFER_SIZE] = {}; ===================================== rts/Weak.c ===================================== @@ -146,7 +146,7 @@ scheduleFinalizers(Capability *cap, StgWeak *list) debugTrace(DEBUG_weak, "weak: batching %d finalizers", n); - StgMutArrPtrs *arr = allocateMutArrPtrs(cap, n, CCS_SYSTEM_OR_NULL); + StgMutArrPtrs *arr = allocateMutArrPtrs(cap, n, NULL, CCS_SYSTEM_OR_NULL); if (RTS_UNLIKELY(arr == NULL)) exitHeapOverflow(); // No write barrier needed here; this array is only going to referred to by this core. SET_INFO((StgClosure *) arr, &stg_MUT_ARR_PTRS_FROZEN_CLEAN_info); ===================================== rts/include/rts/Flags.h ===================================== @@ -118,6 +118,7 @@ typedef struct _DEBUG_FLAGS { bool compact; /* 'C' */ bool continuation; /* 'k' */ bool iomanager; /* 'o' */ + bool ipe; /* 'I' */ } DEBUG_FLAGS; /* See Note [Synchronization of flags and base APIs] */ ===================================== testsuite/driver/testglobals.py ===================================== @@ -72,6 +72,10 @@ class TestConfig: # Was the compiler compiled with -debug? self.debug_rts = False + # Were the compiler + libraries built with IPE-related options + # (e.g. -finfo-table-map, -fdistinct-constructor-tables)? + self.ghc_with_ipe = False + # Was the compiler compiled with LLVM? self.ghc_built_by_llvm = False ===================================== testsuite/driver/testlib.py ===================================== @@ -1074,6 +1074,9 @@ def have_profiling( ) -> bool: def have_threaded( ) -> bool: return config.ghc_with_threaded_rts +def ghc_with_ipe( ) -> bool: + return config.ghc_with_ipe + def in_tree_compiler( ) -> bool: return config.in_tree_compiler ===================================== testsuite/tests/rts/Makefile ===================================== @@ -140,7 +140,7 @@ T20199: .PHONY: EventlogOutput_IPE EventlogOutput_IPE: "$(TEST_HC)" $(TEST_HC_OPTS) -debug -finfo-table-map -v0 EventlogOutput.hs - ./EventlogOutput +RTS -va 2> EventlogOutput_IPE.stderr.log + ./EventlogOutput +RTS -va -DI 2> EventlogOutput_IPE.stderr.log grep "IPE:" EventlogOutput_IPE.stderr.log .PHONY: T23142 ===================================== testsuite/tests/rts/all.T ===================================== @@ -535,6 +535,7 @@ test('T13676', test('InitEventLogging', [ only_ways(['normal']) , extra_run_opts('+RTS -RTS') + , when(ghc_with_ipe(), skip) # IPE builds can change eventlog writer call counts. , req_c ], compile_and_run, ['InitEventLogging_c.c']) @@ -588,6 +589,7 @@ test('cloneThreadStack', [req_c, only_ways(['threaded1']), extra_ways(['threaded test('decodeMyStack', [ omit_ghci, js_broken(22261) # cloneMyStack# not yet implemented + , when(ghc_with_ipe(), skip) # IPE builds can change decoded stack output. ], compile_and_run, ['-finfo-table-map']) # Options: @@ -595,6 +597,7 @@ test('decodeMyStack', test('decodeMyStack_underflowFrames', [ extra_run_opts('+RTS -kc8K -RTS') , omit_ghci, js_broken(22261) # cloneMyStack# not yet implemented + , when(ghc_with_ipe(), skip) # IPE builds can change decoded stack layout/length. ], compile_and_run, ['-finfo-table-map -rtsopts']) # -finfo-table-map intentionally missing @@ -602,6 +605,7 @@ test('decodeMyStack_emptyListForMissingFlag', [ ignore_stdout , ignore_stderr , js_broken(22261) # cloneMyStack# not yet implemented + , when(ghc_with_ipe(), skip) # IPE builds can populate IPE info even without -finfo-table-map on this module. ], compile_and_run, ['']) # Tests RTS flag parsing. Skipped on JS as it uses a distinct RTS. @@ -646,7 +650,7 @@ test('T25280', [unless(opsys('linux'),skip),req_process,js_skip], compile_and_ru test('T25560', [req_c_rts, ignore_stderr], compile_and_run, ['']) test('TestProddableBlockSet', [req_c_rts], multimod_compile_and_run, ['TestProddableBlockSet.c', '-no-hs-main']) -test('T22859', +test('T22859', [js_skip, # This test is vulnerable to changes in allocation behaviour, so we disable it in some ways when(arch('wasm32'), skip), ===================================== testsuite/tests/rts/ipe/all.T ===================================== @@ -8,7 +8,7 @@ test('ipeMap', [extra_files(['ipe_lib.c', 'ipe_lib.h']), c_src, omit_ghci], comp test('ipeEventLog', [ c_src, extra_files(['ipe_lib.c', 'ipe_lib.h']), - extra_run_opts('+RTS -va -RTS'), + extra_run_opts('+RTS -va -DI -RTS'), grep_errmsg('table_name_'), only_ways(debug_ways), normalise_errmsg_fun(noCapabilityOutputFilter), @@ -24,7 +24,7 @@ test('ipeEventLog', test('ipeEventLog_fromMap', [ c_src, extra_files(['ipe_lib.c', 'ipe_lib.h']), - extra_run_opts('+RTS -va -RTS'), + extra_run_opts('+RTS -va -DI -RTS'), grep_errmsg('table_name_'), only_ways(debug_ways), normalise_errmsg_fun(noCapabilityOutputFilter), @@ -34,4 +34,3 @@ test('ipeEventLog_fromMap', when(opsys('darwin'), fragile(0)) ], compile_and_run, ['ipe_lib.c']) - View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/8f45dfca553ce91069e2f9fa10eead… -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/8f45dfca553ce91069e2f9fa10eead… You're receiving this email because of your account on gitlab.haskell.org.

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[Git][ghc/ghc][master] Fix testsuite run for +ipe flavour transformer
by Marge Bot (＠marge-bot) 22 Jan '26

22 Jan '26

Marge Bot pushed to branch master at Glasgow Haskell Compiler / GHC Commits: 4c784f00 by Cheng Shao at 2026-01-22T14:53:19-05:00 Fix testsuite run for +ipe flavour transformer This patch makes the +ipe flavour transformer pass the entire testsuite: - An RTS debug option `-DI` is added, the IPE trace information is now only printed with `-DI`. The test cases that do require IPE trace are now run with `-DI`. - The testsuite config option `ghc_with_ipe` is added, enabled when running the testsuite with `+ipe`, which skips a few tests that are sensitive to eventlog output, allocation patterns etc that can fail under `+ipe`. This is the first step towards #26799. Co-authored-by: Codex <codex(a)openai.com> - - - - - 12 changed files: - docs/users_guide/runtime_control.rst - hadrian/src/Flavour.hs - libraries/ghc-compact/tests/all.T - libraries/ghc-internal/tests/backtraces/all.T - rts/RtsFlags.c - rts/Trace.c - rts/include/rts/Flags.h - testsuite/driver/testglobals.py - testsuite/driver/testlib.py - testsuite/tests/rts/Makefile - testsuite/tests/rts/all.T - testsuite/tests/rts/ipe/all.T Changes: ===================================== docs/users_guide/runtime_control.rst ===================================== @@ -1588,6 +1588,7 @@ recommended for everyday use! .. rts-flag:: -Ds DEBUG: scheduler .. rts-flag:: -Di DEBUG: interpreter +.. rts-flag:: -DI DEBUG: IPE .. rts-flag:: -Dw DEBUG: weak .. rts-flag:: -DG DEBUG: gccafs .. rts-flag:: -Dg DEBUG: gc ===================================== hadrian/src/Flavour.hs ===================================== @@ -384,9 +384,15 @@ omitPragmas = addArgs -- | Build stage2 dependencies with options to enable IPE debugging -- information. enableIPE :: Flavour -> Flavour -enableIPE = addArgs - $ notStage0 ? builder (Ghc CompileHs) - ? pure ["-finfo-table-map", "-fdistinct-constructor-tables"] +enableIPE = + addArgs $ + mconcat + [ notStage0 + ? builder (Ghc CompileHs) + ? pure + ["-finfo-table-map", "-fdistinct-constructor-tables"], + builder Testsuite ? arg "--config=ghc_with_ipe=True" + ] enableLateCCS :: Flavour -> Flavour enableLateCCS = addArgs ===================================== libraries/ghc-compact/tests/all.T ===================================== @@ -20,7 +20,8 @@ test('compact_gc', [fragile_for(17253, ['ghci']), ignore_stdout], compile_and_ru # this test computes closure sizes and those are affected # by the ghci and prof ways, because of BCOs and profiling headers. # Optimization levels slightly change what is/isn't shared so only run in normal mode -test('compact_share', only_ways(['normal']), compile_and_run, ['']) +test('compact_share', [only_ways(['normal']), when(ghc_with_ipe(), skip)], # IPE changes allocation/layout affecting compactSize output. + compile_and_run, ['']) test('compact_bench', [ ignore_stdout, extra_run_opts('100') ], compile_and_run, ['']) test('T17044', normal, compile_and_run, ['']) ===================================== libraries/ghc-internal/tests/backtraces/all.T ===================================== @@ -2,5 +2,5 @@ test('T14532a', [], compile_and_run, ['']) test('T14532b', [], compile_and_run, ['']) test('T26507', [ when(have_profiling(), extra_ways(['prof'])) , when(js_arch(), skip) - , exit_code(1)], compile_and_run, ['']) - + , when(ghc_with_ipe(), skip) # IPE builds include an IPE backtrace section on stderr. + , exit_code(1)], compile_and_run, ['']) ===================================== rts/RtsFlags.c ===================================== @@ -209,6 +209,8 @@ void initRtsFlagsDefaults(void) RtsFlags.DebugFlags.numa = false; RtsFlags.DebugFlags.compact = false; RtsFlags.DebugFlags.continuation = false; + RtsFlags.DebugFlags.iomanager = false; + RtsFlags.DebugFlags.ipe = false; #if defined(PROFILING) RtsFlags.CcFlags.doCostCentres = COST_CENTRES_NONE; @@ -482,6 +484,7 @@ usage_text[] = { #if defined(DEBUG) " -Ds DEBUG: scheduler", " -Di DEBUG: interpreter", +" -DI DEBUG: IPE", " -Dw DEBUG: weak", " -DG DEBUG: gccafs", " -Dg DEBUG: gc", @@ -2311,6 +2314,9 @@ static void read_debug_flags(const char* arg) case 'o': RtsFlags.DebugFlags.iomanager = true; break; + case 'I': + RtsFlags.DebugFlags.ipe = true; + break; default: bad_option( arg ); } ===================================== rts/Trace.c ===================================== @@ -685,7 +685,8 @@ void traceHeapProfSampleString(const char *label, StgWord residency) void traceIPE(const InfoProvEnt *ipe) { #if defined(DEBUG) - if (RtsFlags.TraceFlags.tracing == TRACE_STDERR) { + if (RtsFlags.TraceFlags.tracing == TRACE_STDERR + && RtsFlags.DebugFlags.ipe) { ACQUIRE_LOCK(&trace_utx); char closure_desc_buf[CLOSURE_DESC_BUFFER_SIZE] = {}; ===================================== rts/include/rts/Flags.h ===================================== @@ -118,6 +118,7 @@ typedef struct _DEBUG_FLAGS { bool compact; /* 'C' */ bool continuation; /* 'k' */ bool iomanager; /* 'o' */ + bool ipe; /* 'I' */ } DEBUG_FLAGS; /* See Note [Synchronization of flags and base APIs] */ ===================================== testsuite/driver/testglobals.py ===================================== @@ -72,6 +72,10 @@ class TestConfig: # Was the compiler compiled with -debug? self.debug_rts = False + # Were the compiler + libraries built with IPE-related options + # (e.g. -finfo-table-map, -fdistinct-constructor-tables)? + self.ghc_with_ipe = False + # Was the compiler compiled with LLVM? self.ghc_built_by_llvm = False ===================================== testsuite/driver/testlib.py ===================================== @@ -1074,6 +1074,9 @@ def have_profiling( ) -> bool: def have_threaded( ) -> bool: return config.ghc_with_threaded_rts +def ghc_with_ipe( ) -> bool: + return config.ghc_with_ipe + def in_tree_compiler( ) -> bool: return config.in_tree_compiler ===================================== testsuite/tests/rts/Makefile ===================================== @@ -140,7 +140,7 @@ T20199: .PHONY: EventlogOutput_IPE EventlogOutput_IPE: "$(TEST_HC)" $(TEST_HC_OPTS) -debug -finfo-table-map -v0 EventlogOutput.hs - ./EventlogOutput +RTS -va 2> EventlogOutput_IPE.stderr.log + ./EventlogOutput +RTS -va -DI 2> EventlogOutput_IPE.stderr.log grep "IPE:" EventlogOutput_IPE.stderr.log .PHONY: T23142 ===================================== testsuite/tests/rts/all.T ===================================== @@ -535,6 +535,7 @@ test('T13676', test('InitEventLogging', [ only_ways(['normal']) , extra_run_opts('+RTS -RTS') + , when(ghc_with_ipe(), skip) # IPE builds can change eventlog writer call counts. , req_c ], compile_and_run, ['InitEventLogging_c.c']) @@ -588,6 +589,7 @@ test('cloneThreadStack', [req_c, only_ways(['threaded1']), extra_ways(['threaded test('decodeMyStack', [ omit_ghci, js_broken(22261) # cloneMyStack# not yet implemented + , when(ghc_with_ipe(), skip) # IPE builds can change decoded stack output. ], compile_and_run, ['-finfo-table-map']) # Options: @@ -595,6 +597,7 @@ test('decodeMyStack', test('decodeMyStack_underflowFrames', [ extra_run_opts('+RTS -kc8K -RTS') , omit_ghci, js_broken(22261) # cloneMyStack# not yet implemented + , when(ghc_with_ipe(), skip) # IPE builds can change decoded stack layout/length. ], compile_and_run, ['-finfo-table-map -rtsopts']) # -finfo-table-map intentionally missing @@ -602,6 +605,7 @@ test('decodeMyStack_emptyListForMissingFlag', [ ignore_stdout , ignore_stderr , js_broken(22261) # cloneMyStack# not yet implemented + , when(ghc_with_ipe(), skip) # IPE builds can populate IPE info even without -finfo-table-map on this module. ], compile_and_run, ['']) # Tests RTS flag parsing. Skipped on JS as it uses a distinct RTS. @@ -646,7 +650,7 @@ test('T25280', [unless(opsys('linux'),skip),req_process,js_skip], compile_and_ru test('T25560', [req_c_rts, ignore_stderr], compile_and_run, ['']) test('TestProddableBlockSet', [req_c_rts], multimod_compile_and_run, ['TestProddableBlockSet.c', '-no-hs-main']) -test('T22859', +test('T22859', [js_skip, # This test is vulnerable to changes in allocation behaviour, so we disable it in some ways when(arch('wasm32'), skip), ===================================== testsuite/tests/rts/ipe/all.T ===================================== @@ -8,7 +8,7 @@ test('ipeMap', [extra_files(['ipe_lib.c', 'ipe_lib.h']), c_src, omit_ghci], comp test('ipeEventLog', [ c_src, extra_files(['ipe_lib.c', 'ipe_lib.h']), - extra_run_opts('+RTS -va -RTS'), + extra_run_opts('+RTS -va -DI -RTS'), grep_errmsg('table_name_'), only_ways(debug_ways), normalise_errmsg_fun(noCapabilityOutputFilter), @@ -24,7 +24,7 @@ test('ipeEventLog', test('ipeEventLog_fromMap', [ c_src, extra_files(['ipe_lib.c', 'ipe_lib.h']), - extra_run_opts('+RTS -va -RTS'), + extra_run_opts('+RTS -va -DI -RTS'), grep_errmsg('table_name_'), only_ways(debug_ways), normalise_errmsg_fun(noCapabilityOutputFilter), @@ -34,4 +34,3 @@ test('ipeEventLog_fromMap', when(opsys('darwin'), fragile(0)) ], compile_and_run, ['ipe_lib.c']) - View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/4c784f00a47871cdda7f6fd49728a8c… -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/4c784f00a47871cdda7f6fd49728a8c… You're receiving this email because of your account on gitlab.haskell.org.

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[Git][ghc/ghc][master] rts: avoid Cmm loop to initialize Array#/SmallArray#
by Marge Bot (＠marge-bot) 22 Jan '26

22 Jan '26

Marge Bot pushed to branch master at Glasgow Haskell Compiler / GHC Commits: cdb74049 by Cheng Shao at 2026-01-22T14:52:36-05:00 rts: avoid Cmm loop to initialize Array#/SmallArray# Previously, `newArray#`/`newSmallArray#` called an RTS C function to allocate the `Array#`/`SmallArray#`, then used a Cmm loop to initialize the elements. Cmm doesn't have native for-loop so the code is a bit awkward, and it's less efficient than a C loop, since the C compiler can effectively vectorize the loop with optimizations. So this patch moves the loop that initializes the elements to the C side. `allocateMutArrPtrs`/`allocateSmallMutArrPtrs` now takes a new `init` argument and initializes the elements if `init` is non-NULL. - - - - - 7 changed files: - rts/AllocArray.c - rts/AllocArray.h - rts/ClosureTable.c - rts/Heap.c - rts/PrimOps.cmm - rts/Threads.c - rts/Weak.c Changes: ===================================== rts/AllocArray.c ===================================== @@ -5,6 +5,7 @@ StgMutArrPtrs *allocateMutArrPtrs (Capability *cap, StgWord nelements, + StgClosure *init, CostCentreStack *ccs USED_IF_PROFILING) { /* All sizes in words */ @@ -25,6 +26,12 @@ StgMutArrPtrs *allocateMutArrPtrs (Capability *cap, arr->ptrs = nelements; arr->size = arrsize; + if (init != NULL) { + for (StgWord i = 0; i < nelements; ++i) { + arr->payload[i] = init; + } + } + /* Initialize the card array. Note that memset needs sizes in bytes. */ memset(&(arr->payload[nelements]), 0, mutArrPtrsCards(nelements)); @@ -33,6 +40,7 @@ StgMutArrPtrs *allocateMutArrPtrs (Capability *cap, StgSmallMutArrPtrs *allocateSmallMutArrPtrs (Capability *cap, StgWord nelements, + StgClosure *init, CostCentreStack *ccs USED_IF_PROFILING) { @@ -47,6 +55,13 @@ StgSmallMutArrPtrs *allocateSmallMutArrPtrs (Capability *cap, /* No write barrier needed since this is a new allocation. */ SET_HDR(arr, &stg_SMALL_MUT_ARR_PTRS_DIRTY_info, ccs); arr->ptrs = nelements; + + if (init != NULL) { + for (StgWord i = 0; i < nelements; ++i) { + arr->payload[i] = init; + } + } + return arr; } ===================================== rts/AllocArray.h ===================================== @@ -21,16 +21,19 @@ */ /* Allocate a StgMutArrPtrs for a given number of elements. It is allocated in - * the DIRTY state. + * the DIRTY state. If init is non-NULL, initialize payload elements to init. */ StgMutArrPtrs *allocateMutArrPtrs (Capability *cap, StgWord nelements, + StgClosure *init, CostCentreStack *ccs); -/* Allocate a StgSmallMutArrPtrs for a given number of elements. +/* Allocate a StgSmallMutArrPtrs for a given number of elements. If init is + * non-NULL, initialize payload elements to init. */ StgSmallMutArrPtrs *allocateSmallMutArrPtrs (Capability *cap, StgWord nelements, + StgClosure *init, CostCentreStack *ccs); /* Allocate a StgArrBytes for a given number of bytes. ===================================== rts/ClosureTable.c ===================================== @@ -46,7 +46,7 @@ bool enlargeClosureTable(Capability *cap, ClosureTable *t, int newcapacity) ASSERT(newcapacity > oldcapacity); StgMutArrPtrs *newarr; - newarr = allocateMutArrPtrs(cap, newcapacity, CCS_SYSTEM_OR_NULL); + newarr = allocateMutArrPtrs(cap, newcapacity, NULL, CCS_SYSTEM_OR_NULL); if (RTS_UNLIKELY(newarr == NULL)) return false; StgArrBytes *newfree; @@ -276,4 +276,3 @@ static bool isCompactClosureTable(ClosureTable *t) } return isCompact; } - ===================================== rts/Heap.c ===================================== @@ -279,7 +279,7 @@ StgMutArrPtrs *heap_view_closurePtrs(Capability *cap, StgClosure *closure) { StgClosure **ptrs = (StgClosure **) stgMallocBytes(sizeof(StgClosure *) * size, "heap_view_closurePtrs"); StgWord nptrs = collect_pointers(closure, ptrs); - StgMutArrPtrs *arr = allocateMutArrPtrs(cap, nptrs, cap->r.rCCCS); + StgMutArrPtrs *arr = allocateMutArrPtrs(cap, nptrs, NULL, cap->r.rCCCS); if (RTS_UNLIKELY(arr == NULL)) goto end; SET_INFO((StgClosure *) arr, &stg_MUT_ARR_PTRS_FROZEN_CLEAN_info); ===================================== rts/PrimOps.cmm ===================================== @@ -386,24 +386,11 @@ stg_newArrayzh ( W_ n /* words */, gcptr init ) again: MAYBE_GC(again); - ("ptr" arr) = ccall allocateMutArrPtrs(MyCapability() "ptr", n, CCCS); + ("ptr" arr) = ccall allocateMutArrPtrs(MyCapability() "ptr", n, init "ptr", CCCS); if (arr == NULL) (likely: False) { jump stg_raisezh(HsIface_heapOverflow_closure(W_[ghc_hs_iface])); } - // Initialise all elements of the array with the value init - W_ p; - p = arr + SIZEOF_StgMutArrPtrs; - // Avoid the shift for `WDS(n)` in the inner loop - W_ limit; - limit = arr + SIZEOF_StgMutArrPtrs + WDS(n); - for: - if (p < limit) (likely: True) { - W_[p] = init; - p = p + WDS(1); - goto for; - } - return (arr); } @@ -496,24 +483,11 @@ stg_newSmallArrayzh ( W_ n /* words */, gcptr init ) again: MAYBE_GC(again); - ("ptr" arr) = ccall allocateSmallMutArrPtrs(MyCapability() "ptr", n, CCCS); + ("ptr" arr) = ccall allocateSmallMutArrPtrs(MyCapability() "ptr", n, init "ptr", CCCS); if (arr == NULL) (likely: False) { jump stg_raisezh(HsIface_heapOverflow_closure(W_[ghc_hs_iface])); } - // Initialise all elements of the array with the value init - W_ p; - p = arr + SIZEOF_StgSmallMutArrPtrs; - // Avoid the shift for `WDS(n)` in the inner loop - W_ limit; - limit = arr + SIZEOF_StgSmallMutArrPtrs + WDS(n); - for: - if (p < limit) (likely: True) { - W_[p] = init; - p = p + WDS(1); - goto for; - } - return (arr); } ===================================== rts/Threads.c ===================================== @@ -894,7 +894,7 @@ StgMutArrPtrs *listThreads(Capability *cap) } // Allocate a suitably-sized array... - StgMutArrPtrs *arr = allocateMutArrPtrs(cap, n_threads, cap->r.rCCCS); + StgMutArrPtrs *arr = allocateMutArrPtrs(cap, n_threads, NULL, cap->r.rCCCS); if (RTS_UNLIKELY(arr == NULL)) goto end; // Populate it... ===================================== rts/Weak.c ===================================== @@ -146,7 +146,7 @@ scheduleFinalizers(Capability *cap, StgWeak *list) debugTrace(DEBUG_weak, "weak: batching %d finalizers", n); - StgMutArrPtrs *arr = allocateMutArrPtrs(cap, n, CCS_SYSTEM_OR_NULL); + StgMutArrPtrs *arr = allocateMutArrPtrs(cap, n, NULL, CCS_SYSTEM_OR_NULL); if (RTS_UNLIKELY(arr == NULL)) exitHeapOverflow(); // No write barrier needed here; this array is only going to referred to by this core. SET_INFO((StgClosure *) arr, &stg_MUT_ARR_PTRS_FROZEN_CLEAN_info); View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/cdb74049456a5e58c0923bccb08fc8e… -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/cdb74049456a5e58c0923bccb08fc8e… You're receiving this email because of your account on gitlab.haskell.org.

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[Git][ghc/ghc] Pushed new branch wip/remove-libffi-make
by Cheng Shao (＠TerrorJack) 22 Jan '26

22 Jan '26

Cheng Shao pushed new branch wip/remove-libffi-make at Glasgow Haskell Compiler / GHC -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/tree/wip/remove-libffi-make You're receiving this email because of your account on gitlab.haskell.org.

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[Git][ghc/ghc][wip/labelThread-export] 87 commits: Add missing InVar->OutVar lookup in SetLevels
by Teo Camarasu (＠teo) 22 Jan '26

22 Jan '26

Teo Camarasu pushed to branch wip/labelThread-export at Glasgow Haskell Compiler / GHC Commits: 52d00c05 by Simon Peyton Jones at 2026-01-07T10:24:21-05:00 Add missing InVar->OutVar lookup in SetLevels As #26681 showed, the SetLevels pass was failing to map an InVar to an OutVar. Very silly! I'm amazed it hasn't broken before now. I have improved the type singatures (to mention InVar and OutVar) so it's more obvious what needs to happen. - - - - - ab0a5594 by Cheng Shao at 2026-01-07T10:25:04-05:00 hadrian: drop deprecated pkgHashSplitObjs code path This patch drops deprecated `pkgHashSplitObjs` code path from hadrian, since GHC itself has removed split objs support many versions ago and this code path is unused. - - - - - bb3a2ba1 by Cheng Shao at 2026-01-07T10:25:44-05:00 hadrian: remove linting/assertion in quick-validate flavour The `quick-validate` flavour is meant for testing ghc and passing the testsuite locally with similar settings to `validate` but faster. This patch removes the linting/assertion overhead in `quick-validate` to improve developer experience. I also took the chance to simplify redundant logic of rts/library way definition in `validate` flavour. - - - - - 7971f5dd by Cheng Shao at 2026-01-07T10:26:26-05:00 deriveConstants: clean up unused constants This patch cleans up unused constants from `deriveConstants`, they are not used by C/Cmm code in the RTS, nor compiler-generated code. Co-authored-by: Codex <codex(a)openai.com> - - - - - 4df96993 by Cheng Shao at 2026-01-07T10:27:08-05:00 hadrian: pass -fno-omit-frame-pointer with +debug_info This patch adds `-fno-omit-frame-pointer` as C/C++ compilation flag when compiling with `+debug_info` flavour transformer. It's a sane default when you care about debugging and reliable backtraces, and makes debugging/profiling with bpf easier. - - - - - 8a3900a3 by Aaron Allen at 2026-01-07T10:27:57-05:00 [26705] Include TyCl instances in data fam iface entry Ensures dependent modules are recompiled when the class instances for a data family instance change. resolves #26705 - - - - - a0b980af by Cheng Shao at 2026-01-07T10:28:38-05:00 hadrian: remove unused Hp2Ps/Hpc builders This patch removes the Hp2Ps/Hpc builders from hadrian, they are unused in the build system. Note that the hp2ps/hpc programs are still built and not affected. - - - - - 50a58757 by Cheng Shao at 2026-01-07T10:29:20-05:00 hadrian: only install js files to libdir for wasm/js targets There are certain js files required for wasm/js targets to work, and previously hadrian would install those js files to libdir unconditionally on other targets as well. This could be a minor annoyance for packagers especially when the unused js files contain shebangs that interfere with the packaging process. This patch makes hadrian only selectively install the right js files for the right targets. Co-authored-by: Codex <codex(a)openai.com> - - - - - da40e553 by Simon Peyton Jones at 2026-01-07T10:30:00-05:00 Add flavour transformer assertions_stage1 This allows us to enable -DDEBUG assertions in the stage1 compiler - - - - - ec3cf767 by Cheng Shao at 2026-01-08T06:24:31-05:00 make: remove unused Makefiles from legacy make build system This patch removes unused Makefiles from legacy make build system; now they are never used by hadrian in any way, and they already include common boilerplate mk files that are long gone in the make build system removal, hence the housecleaning. Co-authored-by: Codex <codex(a)openai.com> - - - - - 04ea3f83 by Cheng Shao at 2026-01-08T06:25:13-05:00 compiler: use -O3 as LLVM optimization level for ghc -O2 The GHC driver clamps LLVM optimization level to `-O2` due to LLVM crashes, but those were historical issues many years ago that are no longer relevant for LLVM versions we support today. This patch changes the driver to use `-O3` as LLVM optimization level when compiling with `-O2`, which is a better default when we're willing to trade compilation time for faster generated code. - - - - - 472df471 by Peter Trommler at 2026-01-08T13:28:54-05:00 Use half-word literals in info tables With this commit info tables are mapped to the same assembler code on big-endian and little-endian platforms. Fixes #26579. - - - - - 393f9c51 by Simon Peyton Jones at 2026-01-08T13:29:35-05:00 Refactor srutOkForBinderSwap This MR does a small refactor: * Moves `scrutOkForBinderSwap` and `BinderSwapDecision` to GHC.Core.Utils * Inverts the sense of the coercion it returns, which makes more sense No effect on behaviour - - - - - ad76fb0f by Simon Peyton Jones at 2026-01-08T13:29:36-05:00 Improve case merging This small MR makes case merging happen a bit more often than it otherwise could, by getting join points out of the way. See #26709 and GHC.Core.Utils Note [Floating join points out of DEFAULT alternatives] - - - - - 4c9395f5 by Cheng Shao at 2026-01-08T13:30:16-05:00 hadrian: remove broken hsc2hs flag when cross compiling to windows This patch removes the `--via-asm` hsc2hs flag when cross compiling to windows. With recent llvm-mingw toolchain, it would fail with: ``` x86_64-w64-mingw32-hsc2hs: Cannot combine instructions: [Quad 8,Long 4,Long 241,Ref ".Ltmp1-.Ltmp0"] ``` The hsc2hs default `--cross-compile` logic is slower but works. - - - - - 71fdef55 by Simon Peyton Jones at 2026-01-08T13:30:57-05:00 Try harder to keep the substitution empty Avoid unnecessary cloning of variables in the Simplifier. Addresses #26724, See Note [Keeping the substitution empty] We get some big wins in compile time Metrics: compile_time/bytes allocated ------------------------------------- Baseline Test Metric value New value Change ---------------------------------------------------------------------------- CoOpt_Singletons(normal) ghc/alloc 721,544,088 692,174,216 -4.1% GOOD LargeRecord(normal) ghc/alloc 1,268,031,157 1,265,168,448 -0.2% T14766(normal) ghc/alloc 918,218,533 688,432,296 -25.0% GOOD T15703(normal) ghc/alloc 318,103,629 306,638,016 -3.6% GOOD T17836(normal) ghc/alloc 419,174,584 418,400,824 -0.2% T18478(normal) ghc/alloc 471,042,976 470,261,376 -0.2% T20261(normal) ghc/alloc 573,387,162 563,663,336 -1.7% T24984(normal) ghc/alloc 87,832,666 87,636,168 -0.2% T25196(optasm) ghc/alloc 1,103,284,040 1,101,376,992 -0.2% hard_hole_fits(normal) ghc/alloc 224,981,413 224,608,208 -0.2% geo. mean -0.3% minimum -25.0% maximum +0.1% Metric Decrease: CoOpt_Singletons T14766 T15703 - - - - - 30341168 by Simon Peyton Jones at 2026-01-08T13:31:38-05:00 Add regression test for #24867 - - - - - 1ac1a541 by Julian Ospald at 2026-01-09T02:48:53-05:00 Support statically linking executables properly Fixes #26434 In detail, this does a number of things: * Makes GHC aware of 'extra-libraries-static' (this changes the package database format). * Adds a switch '-static-external' that will honour 'extra-libraries-static' to link external system dependencies statically. * Adds a new field to settings/targets: "ld supports verbatim namespace". This field is used by '-static-external' to conditionally use '-l:foo.a' syntax during linking, which is more robust than trying to find the absolute path to an archive on our own. * Adds a switch '-fully-static' that is meant as a high-level interface for e.g. cabal. This also honours 'extra-libraries-static'. This also attempts to clean up the confusion around library search directories. At the moment, we have 3 types of directories in the package database format: * library-dirs * library-dirs-static * dynamic-library-dirs However, we only have two types of linking: dynamic or static. Given the existing logic in 'mungeDynLibFields', this patch assumes that 'library-dirs' is really just nothing but a fallback and always prefers the more specific variants if they exist and are non-empty. Conceptually, we should be ok with even just one search dirs variant. Haskell libraries are named differently depending on whether they're static or dynamic, so GHC can conveniently pick the right one depending on the linking needs. That means we don't really need to play tricks with search paths to convince the compiler to do linking as we want it. For system C libraries, the convention has been anyway to place static and dynamic libs next to each other, so we need to deal with that issue anyway and it is outside of our control. But this is out of the scope of this patch. This patch is backwards compatible with cabal. Cabal should however be patched to use the new '-fully-static' switch. - - - - - ad3c808d by Julian Ospald at 2026-01-09T02:48:53-05:00 Warn when "-dynamic" is mixed with "-staticlib" - - - - - 322dd672 by Matthew Pickering at 2026-01-09T02:49:35-05:00 rts: Use INFO_TABLE_CONSTR for stg_dummy_ret_closure Since the closure type is CONSTR_NOCAF, we need to use INFO_TABLE_CONSTR to populate the constructor description field (this crashes ghc-debug when decoding AP_STACK frames sometimes) Fixes #26745 - - - - - 039bac4c by Ben Gamari at 2026-01-09T20:22:16-05:00 ghc-internal: Move STM utilities out of GHC.Internal.Conc.Sync This is necessary to avoid an import cycle on Windows when importing `GHC.Internal.Exception.Context` in `GHC.Internal.Conc.Sync`. On the road to address #25365. - - - - - 8c389e8c by Ben Gamari at 2026-01-09T20:22:16-05:00 base: Capture backtrace from throwSTM Implements core-libraries-committee#297. Fixes #25365. - - - - - e1ce1fc3 by Ben Gamari at 2026-01-09T20:22:16-05:00 base: Annotate rethrown exceptions in catchSTM with WhileHandling Implements core-libraries-committee#298 - - - - - c4ebdbdf by Cheng Shao at 2026-01-09T20:23:06-05:00 compiler: make getPrim eagerly evaluate its result This commit makes `GHC.Utils.Binary.getPrim` eagerly evaluate its result, to avoid accidental laziness when future patches build other binary parsers using `getPrim`. - - - - - 66a0c4f7 by Cheng Shao at 2026-01-09T20:23:06-05:00 compiler: implement fast get/put for Word16/Word32/Word64 Previously, `GHC.Utils.Binary` contains `get`/`put` functions for `Word16`/`Word32`/`Word64` which always loads and stores them as big-endian words at a potentially unaligned address. The previous implementation is based on loads/stores of individual bytes and concatenating bytes with bitwise operations, which currently cannot be fused to a single load/store operation by GHC. This patch implements fast `get`/`put` functions for `Word16`/`Word32`/`Word64` based on a single memory load/store, with an additional `byteSwap` operation on little-endian hosts. It is based on unaligned load/store primops added since GHC 9.10, and we already require booting with at least 9.10, so it's about time to switch to this faster path. - - - - - 641ec3f0 by Simon Peyton Jones at 2026-01-09T20:23:55-05:00 Fix scoping errors in specialisation Using -fspecialise-aggressively in #26682 showed up a couple of subtle errors in the type-class specialiser. * dumpBindUDs failed to call `deleteCallsMentioning`, resulting in a call that mentioned a dictionary that was not in scope. This call has been missing since 2009! commit c43c981705ec33da92a9ce91eb90f2ecf00be9fe Author: Simon Peyton Jones <simonpj(a)microsoft.com> Date: Fri Oct 23 16:15:51 2009 +0000 Fixed by re-combining `dumpBindUDs` and `dumpUDs`. * I think there was another bug involving the quantified type variables in polymorphic specialisation. In any case I refactored `specHeader` and `spec_call` so that the former looks for the extra quantified type variables rather than the latter. This is quite a worthwhile simplification: less code, easier to grok. Test case in simplCore/should_compile/T26682, brilliantly minimised by @sheaf. - - - - - 2433e91d by Cheng Shao at 2026-01-09T20:24:43-05:00 compiler: change sectionProtection to take SectionType argument This commit changes `sectionProtection` to only take `SectionType` argument instead of whole `Section`, since it doesn't need the Cmm section content anyway, and it can then be called in parts of NCG where we only have a `SectionType` in scope. - - - - - e5926fbe by Cheng Shao at 2026-01-09T20:24:43-05:00 compiler: change isInitOrFiniSection to take SectionType argument This commit changes `isInitOrFiniSection` to only take `SectionType` argument instead of whole `Section`, since it doesn't need the Cmm section content anyway, and it can then be called in parts of NCG where we only have a `SectionType` in scope. Also marks it as exported. - - - - - 244d57d7 by Cheng Shao at 2026-01-09T20:24:43-05:00 compiler: fix split sections on windows This patch fixes split sections on windows by emitting the right COMDAT section header in NCG, see added comment for more explanation. Fix #26696 #26494. ------------------------- Metric Decrease: LargeRecord T9675 size_hello_artifact size_hello_artifact_gzip size_hello_unicode size_hello_unicode_gzip Metric Increase: T13035 ------------------------- Co-authored-by: Codex <codex(a)openai.com> - - - - - 182f3d0f by Cheng Shao at 2026-01-09T20:25:28-05:00 iserv: add comment about -fkeep-cafs - - - - - 49675b69 by Matthew Craven at 2026-01-09T20:26:14-05:00 Account for "stupid theta" in demand sig for DataCon wrappers Fixes #26748. - - - - - f3c18890 by Samuel Thibault at 2026-01-10T15:48:22+01:00 hurd: Fix getExecutablePath build 3939a8bf93e27 ("GNU/Hurd: Add getExecutablePath support") added using /proc/self/exe for GNU/Hurd but missed adding the required imports for the corresponding code. - - - - - 7f15bd15 by Samuel Thibault at 2026-01-12T07:16:25-05:00 Fix the OS string encoding for GNU/Hurd Following https://github.com/haskell/cabal/pull/9434/files , and as seen in the various gnu_HOST_OS usages in the source code, it is expected that GNU/Hurd is advertised as "gnu", like the autotools do. - - - - - 1db2f240 by Andrew Lelechenko at 2026-01-12T07:17:06-05:00 Add since annotation for Data.Bifoldable1 Fixes #26432 - - - - - e038a383 by Sven Tennie at 2026-01-12T07:17:49-05:00 Ignore Windows CI tool directories in Git Otherwise, we see thousands of changes in `git status` which is very confusing to work with. - - - - - 023c301c by sheaf at 2026-01-13T04:57:30-05:00 Don't re-use stack slots for growing registers This commit avoids re-using a stack slot for a register that has grown but already had a stack slot. For example, suppose we have stack slot assigments %v1 :: FF64 |-> StackSlot 0 %v2 :: FF64 |-> StackSlot 1 Later, we start using %v1 at a larger format (e.g. F64x2) and we need to spill it again. Then we **must not** use StackSlot 0, as a spill at format F64x2 would clobber the data in StackSlot 1. This can cause some fragmentation of the `StackMap`, but that's probably OK. Fixes #26668 - - - - - d0966e64 by fendor at 2026-01-13T04:58:11-05:00 Remove `traceId` from ghc-pkg executable - - - - - 20d7efec by Simon Peyton Jones at 2026-01-13T12:41:22-05:00 Make SpecContr rules fire a bit later See #26615 and Note [SpecConstr rule activation] - - - - - 8bc4eb8c by Andrew Lelechenko at 2026-01-13T12:42:03-05:00 Upgrade mtl submodule to 2.3.2 Fixes #26656 - - - - - c94aaacd by Cheng Shao at 2026-01-13T12:42:44-05:00 compiler: remove iserv and only use on-demand external interpreter This patch removes `iserv` from the tree completely. Hadrian would no longer build or distribute `iserv`, and the GHC driver would use the on-demand external interpreter by default when invoked with `-fexternal-interpreter`, without needing to specify `-pgmi ""`. This has multiple benefits: - It allows cleanup of a lot of legacy hacks in the hadrian codebase. - It paves the way for running cross ghc's iserv via cross emulator (#25523), fixing TH/ghci support for cross targets other than wasm/js. - - - - - c1fe0097 by Peter Trommler at 2026-01-14T03:54:49-05:00 PPC NCG: Fix shift right MO code The shift amount in shift right [arithmetic] MOs is machine word width. Therefore remove unnecessary zero- or sign-extending of shift amount. It looks harmless to extend the shift amount argument because the shift right instruction uses only the seven lowest bits (i. e. mod 128). But now we have a conversion operation from a smaller type to word width around a memory load at word width. The types are not matching up but there is no check done in CodeGen. The necessary conversion from word width down to the smaller width would be translated into a no-op on PowerPC anyway. So all seems harmless if it was not for a small optimisation in getRegister'. In getRegister' a load instruction with the smaller width of the conversion operation was generated. This loaded the most significant bits of the word in memory on a big-endian platform. These bits were zero and hence shift right was used with shift amount zero and not one as required in test Sized. Fixes #26519 - - - - - 2dafc65a by Cheng Shao at 2026-01-14T03:55:31-05:00 Tree-wide cleanup of cygwin logic GHC has not supported cygwin for quite a few years already, and will not resume support in the forseeable future. The only supported windows toolchain is clang64/clangarm64 of the msys2 project. This patch cleans up the unused cygwin logic in the tree. Co-authored-by: Codex <codex(a)openai.com> - - - - - 66b96e2a by Teo Camarasu at 2026-01-14T03:56:13-05:00 Set default eventlog-flush-interval to 5s Resolves #26707 - - - - - d0254579 by Andrew Lelechenko at 2026-01-14T03:56:53-05:00 Document when -maxN RTS option was added - - - - - f25e2b12 by Cheng Shao at 2026-01-14T11:10:39-05:00 testsuite: remove obsolete --ci option from the testsuite driver This patch removes the obsolete `--ci` option from the testsuite driver: neither the CI scripts nor hadrian ever invokes the testsuite driver with `--ci`, and the perf notes are always fetched to the `refs/notes/perf` local reference anyway. - - - - - 7964763b by Julian Ospald at 2026-01-14T11:11:31-05:00 Fix fetch_cabal * download cabal if the existing one is of an older version * fix FreeBSD download url * fix unpacking on FreeBSD - - - - - 6b0129c1 by Julian Ospald at 2026-01-14T11:11:31-05:00 Bump toolchain in CI - - - - - 0f53ccc6 by Julian Ospald at 2026-01-14T11:11:31-05:00 Use libffi-clib Previously, we would build libffi via hadrian and bundle it manually with the GHC bindist. This now moves all that logic out of hadrian and allows us to have a clean Haskell package to build and link against and ship it without extra logic. This patch still retains the ability to link against a system libffi. The main reason of bundling libffi was that on some platforms (e.g. FreeBSD and Mac), system libffi is not visible to the C toolchain by default, so users would require settings in e.g. cabal to be able to compile anything. This adds the submodule libffi-clib to the repository. - - - - - 5e1cd595 by Peng Fan at 2026-01-14T11:12:26-05:00 NCG/LA64: add support for la664 micro architecture Add '-mla664' flag to LA664, which has some new features: atomic instructions, dbar hints, etc. 'LA464' is the default so that unrecognized instructions are not generated. - - - - - c56567ec by Simon Peyton Jones at 2026-01-15T23:19:04+00:00 Add evals for strict data-con args in worker-functions This fixes #26722, by adding an eval in a worker for arguments of strict data constructors, even if the function body uses them strictly. See (WIS1) in Note [Which Ids should be strictified] I took the opportunity to make substantial improvements in the documentation for call-by-value functions. See especially Note [CBV Function Ids: overview] in GHC.Types.Id.Info Note [Which Ids should be CBV candidates?] ditto Note [EPT enforcement] in GHC.Stg.EnforceEpt among others. - - - - - 9719ce5d by Simon Peyton Jones at 2026-01-15T23:19:04+00:00 Improve `interestingArg` This function analyses a function's argument to see if it is interesting enough to deserve an inlining discount. Improvements for * LitRubbish arguments * exprIsExpandable arguments See Note [Interesting arguments] which is substantially rewritten. - - - - - 7b616b9f by Cheng Shao at 2026-01-16T06:45:00-05:00 compiler: fix regression when compiling foreign stubs in the rts unit This patch fixes a regression when compiling foreign stubs in the rts unit introduced in 05e25647f72bc102061af3f20478aa72bff6ff6e. A simple revert would fix it, but it's better to implement a proper fix with comment for better understanding of the underlying problem, see the added comment for explanation. Co-authored-by: Codex <codex(a)openai.com> - - - - - c343ef64 by Sylvain Henry at 2026-01-16T06:45:51-05:00 base: remove GHC.JS.Prim.Internal.Build (#23432) See accepted CLC proposal https://github.com/haskell/core-libraries-committee/issues/329 - - - - - 29c0aceb by Simon Peyton Jones at 2026-01-16T17:18:11-05:00 Improve newtype unwrapping Ticket #26746 describes several relatively-minor shortcomings of newtype unwrapping. This MR addresses them, while also (arguably) simplifying the code a bit. See new Note [Solving newtype equalities: overview] and Note [Decomposing newtype equalities] and Note [Eager newtype decomposition] and Note [Even more eager newtype decomposition] For some reason, on Windows only, runtime allocations decrease for test T5205 (from 52k to 48k). I have not idea why. No change at all on Linux. I'm just going to accept the change. (I saw this same effect in another MR so I think it's a fault in the baseline.) Metric Decrease: T5205 - - - - - 8b59e62c by Andreas Klebinger at 2026-01-16T17:18:52-05:00 testsuite: Widen acceptance window for T5205. Fixes #26782 - - - - - 9e5e0234 by mangoiv at 2026-01-17T06:03:03-05:00 add a new issue template for getting verified To reduce spam created by new users, we will in future not grant any rights but reporting issues to new users. That is why we will have to be able to verify them. The added issue template serves that purpose. - - - - - b18b2c42 by Cheng Shao at 2026-01-17T06:03:44-05:00 llvm: fix split sections for llvm backend This patch fixes split sections for llvm backend: - Pass missing `--data-sections`/`--function-sections` flags to llc/opt. - Use `(a)llvm.compiler.used` instead of `(a)llvm.used` to avoid sections being unnecessarily retained at link-time. Fixes #26770. ------------------------- Metric Decrease: libdir size_hello_artifact size_hello_unicode ------------------------- Co-authored-by: Codex <codex(a)openai.com> - - - - - ebf66f67 by Cheng Shao at 2026-01-17T13:16:50-05:00 Update autoconf scripts Scripts taken from autoconf a2287c3041a3f2a204eb942e09c015eab00dc7dd - - - - - 598624b9 by Andreas Klebinger at 2026-01-17T13:17:32-05:00 CString.hs: Update incorrect comment. Fixes #26322 - - - - - eea2036b by Cheng Shao at 2026-01-18T10:00:49-05:00 libraries: bump haskeline submodule to 0.8.4.1 This patch bumps the haskeline submodule to 0.8.4.1 which includes an important fix for an ANSI handling bug on Windows (https://github.com/haskell/haskeline/pull/126) - - - - - 87d8f6c2 by Cheng Shao at 2026-01-18T10:01:30-05:00 hadrian: replace default -H32m/-H64m with -O64M to improve mutator productivity Most hadrian build flavours pass `-H32m`/`-H64m` to GHC as conventional wisdom to improve mutator productivity and reduce GC overhead. They were inherited from the legacy Make build system, and there used to be make flags to instrument a build process with `-Rghc-timing` option to collect GC stats of each GHC run from stderr. It's time to revisit whether there are better defaults for `-H32m`/`-H64m`, and this patch changes it to `-O64M` which indeed improves mutator productivity based on real statistics. `-O64M` is more aggressive than `-H64m`; it allows the old generation to grow to at least 64M before triggering major GC and reduces major GC runs. The stats of a clean build with `validate` flavour and `-H64m`: ``` h64m.log matched RTS stat lines: 5499 sum MUT cpu : 2400.808 s sum GC cpu : 1378.292 s sum MUT elapsed : 2788.253 s sum GC elapsed : 1389.233 s GC/MUT cpu ratio : 0.574 (GC is 57.4% of MUT) GC/MUT elapsed ratio : 0.498 (GC is 49.8% of MUT) GC fraction of (MUT+GC) cpu : 36.5% GC fraction of (MUT+GC) elapsed : 33.3% per-line GC/MUT cpu ratio: median 0.691, p90 1.777 per-line GC/MUT elapsed ratio: median 0.519, p90 1.081 ``` The stats of a clean build with `validate` flavour and `-O64M`: ``` o64m.log matched RTS stat lines: 5499 sum MUT cpu : 2377.383 s sum GC cpu : 1127.146 s sum MUT elapsed : 2758.857 s sum GC elapsed : 1135.587 s GC/MUT cpu ratio : 0.474 (GC is 47.4% of MUT) GC/MUT elapsed ratio : 0.412 (GC is 41.2% of MUT) GC fraction of (MUT+GC) cpu : 32.2% GC fraction of (MUT+GC) elapsed : 29.2% per-line GC/MUT cpu ratio: median 0.489, p90 1.099 per-line GC/MUT elapsed ratio: median 0.367, p90 0.806 ``` Mutator time is roughly in the same ballpark, but GC CPU time has reduced by 18.22%, and mutator productivity has increased from 63.5% to 67.8%. - - - - - 8372e13d by Cheng Shao at 2026-01-18T10:02:12-05:00 rts: remove unused .def files from rts/win32 This patch removes unused .def files from `rts/win32`, given we don't build .dll files for rts/ghc-internal/ghc-prim at all. Even when we resurrect win32 dll support at some point in the future, these .def files still contain incorrect symbols anyway and won't be of any use. - - - - - f6af485d by Cheng Shao at 2026-01-18T10:03:19-05:00 .gitmodules: use gitlab mirror for the libffi-clib submodule This patch fixes .gitmodules to use the gitlab mirror for the libffi-clib submodule, to make it coherent with other submodules that allow ghc developers to experiment with wip branches in submodules for ghc patches. Fixes #26783. - - - - - 41432d25 by Cheng Shao at 2026-01-18T10:05:13-05:00 hadrian: remove the horrible i386 speedHack When hadrian builds certain rts objects for i386, there's a horrible speedHack that forces -fno-PIC even for dynamic ways of those objects. This is not compatible with newer versions of gcc/binutils as well as clang/lld, and this patch removes it. Fixes #26792. - - - - - 323eb8f0 by Cheng Shao at 2026-01-18T21:48:19-05:00 hadrian: enable split sections for cross stage0 This patch fixes a minor issue with `splitSectionsArgs` in hadrian: previously, it's unconditionally disabled for stage0 libraries because it's not going to be shipped in the final bindists. But it's only true when not cross compiling. So for now we also need to enable it for cross stage0 as well. - - - - - 3fadfefe by Andreas Klebinger at 2026-01-18T21:49:01-05:00 RTS: Document -K behaviour better - - - - - 30f442a9 by Teo Camarasu at 2026-01-20T13:57:26-05:00 base: don't expose GHC.Num.{BigNat, Integer, Natural} We no longer expose GHC.Num.{BigNat, Integer, Natural} from base instead users should get these modules from ghc-bignum. We make this change to insulate end users from changes to GHC's implementation of big numbers. Implements CLC proposal 359: https://github.com/haskell/core-libraries-committee/issues/359 - - - - - 75a9053d by Teo Camarasu at 2026-01-20T13:58:07-05:00 base: deprecate GHC internals in GHC.Num Implements CLC proposal: https://github.com/haskell/core-libraries-committee/issues/360 - - - - - 9534b032 by Andreas Klebinger at 2026-01-20T13:58:50-05:00 ghc-experimental: Update Changelog I tried to reconstruct a high level overview of the changes and when they were made since we introduced it. Fixes #26506 Co-authored-by: Teo Camarasu <teofilcamarasu(a)gmail.com> - - - - - 346f2f5a by Cheng Shao at 2026-01-20T13:59:30-05:00 hadrian: remove RTS options in ghc-in-ghci flavour This patch removes the RTS options passed to ghc in ghc-in-ghci flavour, to workaround command line argument handling issue in hls/hie-boot that results in `-O64M` instead of `+RTS -O64M -RTS` being passed to ghc. It's not a hadrian bug per se, since ghc's own ghc-in-ghci multi repl works fine, but we should still make sure HLS works. Closes #26801. - - - - - 759fd15a by Andreas Klebinger at 2026-01-21T16:05:28-05:00 Don't build GHC with -Wcompat Without bumping the boot compiler the warnings it produces are often not actionable leading to pointless noise. Fixes #26800 - - - - - 3172db94 by Torsten Schmits at 2026-01-21T16:06:11-05:00 Use the correct field of ModOrigin when formatting error message listing hidden reexports - - - - - 485c12b2 by Cheng Shao at 2026-01-21T16:06:54-05:00 Revert "hadrian: handle findExecutable "" gracefully" This reverts commit 1e5752f64a522c4025365856d92f78073a7b3bba. The underlying issue has been fixed in https://github.com/haskell/directory/commit/75828696e7145adc09179111a0d631b… and present since 1.3.9.0, and hadrian directory lower bound is 1.3.9.0, so we can revert our own in house hack now. - - - - - 5efb58dc by Cheng Shao at 2026-01-21T16:07:36-05:00 rts: fix typo in TICK_ALLOC_RTS This patch fixes a typo in the `TICK_ALLOC_RTS` macro, the original `bytes` argument was silently dropped. The Cmm code has its own version of `TICK_ALLOC_RTS` not affected by this typo, it affected the C RTS, and went unnoticed because the variable `n` happened to also be available at its call site. But the number was incorrect. Also fixes its call site since `WDS()` is not available in C. - - - - - c406ea69 by Cheng Shao at 2026-01-21T16:07:36-05:00 rts: remove broken & unused ALLOC_P_TICKY This patch removes the `ALLOC_P_TICKY` macro from the rts, it's unused, and its expanded code is already broken. - - - - - 34a27e20 by Simon Peyton Jones at 2026-01-21T16:08:17-05:00 Make the implicit-parameter class have representational role This MR addresses #26737, by making the built-in class IP have a representational role for its second parameter. See Note [IP: implicit parameter class] in ghc-internal:GHC.Internal.Classes.IP In fact, IP is (unfortunately, currently) exposed by base:GHC.Base, so we ran a quick CLC proposal to agree the change: https://github.com/haskell/core-libraries-committee/issues/385 Some (small) compilations get faster because they only need to load (small) interface file GHC.Internal.Classes.IP.hi, rather than (large) GHC.Internal.Classes.hi. Metric Decrease: T10421 T12150 T12425 T24582 T5837 T5030 - - - - - ca79475f by Cheng Shao at 2026-01-21T16:09:00-05:00 testsuite: avoid re.sub in favor of simple string replacements This patch refactors the testsuite driver and avoids the usage of re.sub in favor of simple string replacements when possible. The changes are not comprehensive, and there are still a lot of re.sub usages lingering around the tree, but this already addresses a major performance bottleneck in the testsuite driver that might has to do with quadratic or worse slowdown in cpython's regular expression engine when handling certain regex patterns with large strings. Especially on i386, and i386 jobs are the bottlenecks of all full-ci validate pipelines! Here are the elapsed times of testing x86_64/i386 with -j48 before this patch: x86_64: `Build completed in 6m06s` i386: `Build completed in 1h36m` And with this patch: x86_64: `Build completed in 4m55s` i386: `Build completed in 4m23s` Fixes #26786. Co-authored-by: Codex <codex(a)openai.com> - - - - - 88c93796 by Zubin Duggal at 2026-01-21T16:09:42-05:00 ghc-toolchain: Also configure windres on non-windows platforms. It may be needed for cross compilation. Fixes #24588 - - - - - 9788c0ec by Cheng Shao at 2026-01-21T16:10:24-05:00 ghci: print external interpreter trace messages to stderr instead of stdout This patch makes ghci print external interpreter trace messages to stderr instead of stdout, which is a much saner choice for diagnostic information. Closes #26807. - - - - - 0491f08a by Sylvain Henry at 2026-01-22T03:44:26-05:00 GC: don't use CAS without PARALLEL_GC on If we're not using the parallel GC, there is no reason to do a costly CAS. This was flagged as taking time in a perf profile. - - - - - 211a8f56 by Sylvain Henry at 2026-01-22T03:44:26-05:00 GC: suffix parallel GC with "par" instead of "thr" Avoid some potential confusion (see discussion in !15351). - - - - - 77a23cbd by fendor at 2026-01-22T03:45:08-05:00 Remove blanket ignore that covers libraries/ - - - - - 18bf7f5c by Léana Jiang at 2026-01-22T08:58:45-05:00 doc: update Flavour type in hadrian user-settings - - - - - 3d5a1365 by Cheng Shao at 2026-01-22T08:59:28-05:00 hadrian: add missing notCross predicate for stage0 -O0 There are a few hard-coded hadrian args that pass -O0 when compiling some heavy modules in stage0, which only makes sense when not cross-compiling and when cross-compiling we need properly optimized stage0 packages. So this patch adds the missing `notCross` predicate in those places. - - - - - ee937134 by Matthew Pickering at 2026-01-22T09:00:10-05:00 Fix ghc-experimental GHC.Exception.Backtrace.Experimental module This module wasn't added to the cabal file so it was never compiled or included in the library. - - - - - 1b490f5a by Zubin Duggal at 2026-01-22T09:00:53-05:00 hadrian: Add ghc-{experimental,internal}.cabal to the list of dependencies of the doc target We need these files to detect the version of these libraries Fixes #26738 - - - - - f324373c by Oleg Grenrus at 2026-01-22T18:20:06+00:00 Export labelThread from Control.Concurrent - - - - - 298 changed files: - .gitignore - .gitlab/ci.sh - .gitlab/generate-ci/gen_ci.hs - + .gitlab/issue_templates/get-verified.md - .gitlab/jobs.yaml - .gitmodules - CODEOWNERS - cabal.project-reinstall - compiler/GHC/Builtin/Names.hs - compiler/GHC/Cmm.hs - compiler/GHC/Cmm/Info.hs - compiler/GHC/Cmm/InitFini.hs - compiler/GHC/Cmm/Utils.hs - compiler/GHC/CmmToAsm/AArch64/Ppr.hs - compiler/GHC/CmmToAsm/Config.hs - compiler/GHC/CmmToAsm/PPC/CodeGen.hs - compiler/GHC/CmmToAsm/Ppr.hs - compiler/GHC/CmmToAsm/Reg/Linear.hs - compiler/GHC/CmmToAsm/Reg/Linear/StackMap.hs - compiler/GHC/CmmToAsm/Wasm/FromCmm.hs - compiler/GHC/CmmToAsm/X86/Ppr.hs - compiler/GHC/CmmToC.hs - compiler/GHC/CmmToLlvm.hs - compiler/GHC/CmmToLlvm/Base.hs - compiler/GHC/CmmToLlvm/Data.hs - compiler/GHC/Core/FamInstEnv.hs - compiler/GHC/Core/Opt/Arity.hs - compiler/GHC/Core/Opt/OccurAnal.hs - compiler/GHC/Core/Opt/SetLevels.hs - compiler/GHC/Core/Opt/Simplify/Env.hs - compiler/GHC/Core/Opt/Simplify/Iteration.hs - compiler/GHC/Core/Opt/Simplify/Utils.hs - compiler/GHC/Core/Opt/SpecConstr.hs - compiler/GHC/Core/Opt/Specialise.hs - compiler/GHC/Core/Opt/WorkWrap.hs - compiler/GHC/Core/Opt/WorkWrap/Utils.hs - compiler/GHC/Core/Rules.hs - compiler/GHC/Core/Subst.hs - compiler/GHC/Core/Tidy.hs - compiler/GHC/Core/TyCo/Subst.hs - compiler/GHC/Core/Unfold.hs - compiler/GHC/Core/Unfold/Make.hs - compiler/GHC/Core/Utils.hs - compiler/GHC/CoreToStg/Prep.hs - compiler/GHC/Driver/Backpack.hs - compiler/GHC/Driver/CodeOutput.hs - compiler/GHC/Driver/Config/CmmToAsm.hs - compiler/GHC/Driver/Config/Interpreter.hs - compiler/GHC/Driver/Downsweep.hs - compiler/GHC/Driver/DynFlags.hs - compiler/GHC/Driver/MakeFile.hs - compiler/GHC/Driver/Pipeline.hs - compiler/GHC/Driver/Pipeline/Execute.hs - compiler/GHC/Driver/Session.hs - compiler/GHC/Iface/Recomp.hs - compiler/GHC/Linker/Dynamic.hs - compiler/GHC/Linker/Executable.hs - compiler/GHC/Linker/Loader.hs - compiler/GHC/Linker/Unit.hs - compiler/GHC/Runtime/Interpreter/Init.hs - compiler/GHC/Settings.hs - compiler/GHC/Settings/IO.hs - compiler/GHC/Stg/EnforceEpt.hs - compiler/GHC/Stg/Lint.hs - compiler/GHC/StgToCmm/Closure.hs - compiler/GHC/StgToCmm/Expr.hs - compiler/GHC/StgToJS/Linker/Utils.hs - compiler/GHC/SysTools/Terminal.hs - compiler/GHC/Tc/Instance/Family.hs - compiler/GHC/Tc/Solver/Equality.hs - compiler/GHC/Tc/Solver/Monad.hs - compiler/GHC/Types/Id.hs - compiler/GHC/Types/Id/Info.hs - 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[Git][ghc/ghc][wip/26805] Rejig the NeededEvId stuff again!!
by Simon Peyton Jones (＠simonpj) 22 Jan '26

22 Jan '26

Simon Peyton Jones pushed to branch wip/26805 at Glasgow Haskell Compiler / GHC Commits: 22f6f55e by Simon Peyton Jones at 2026-01-22T17:42:22+00:00 Rejig the NeededEvId stuff again!! Fixes #26772 I hope - - - - - 16 changed files: - compiler/GHC/Core/TyCo/Rep.hs - compiler/GHC/Core/TyCo/Subst.hs - compiler/GHC/Core/TyCo/Tidy.hs - compiler/GHC/Tc/Gen/Expr.hs - compiler/GHC/Tc/Solver/Default.hs - compiler/GHC/Tc/Solver/Equality.hs - compiler/GHC/Tc/Solver/Monad.hs - compiler/GHC/Tc/Solver/Solve.hs - compiler/GHC/Tc/Types/Constraint.hs - compiler/GHC/Tc/Types/Evidence.hs - compiler/GHC/Tc/Utils/Monad.hs - compiler/GHC/Tc/Utils/TcMType.hs - compiler/GHC/Tc/Utils/Unify.hs - compiler/GHC/Tc/Zonk/TcType.hs - compiler/GHC/Tc/Zonk/Type.hs - compiler/GHC/Utils/Trace.hs Changes: ===================================== compiler/GHC/Core/TyCo/Rep.hs ===================================== @@ -1688,11 +1688,9 @@ holes `HoleCo`, which get filled in later. -- | A coercion to be filled in by the type-checker. See Note [Coercion holes] data CoercionHole - = CoercionHole { ch_co_var :: CoVar - -- See Note [Coercion holes] wrinkle (COH2) - - , ch_ref :: IORef (Maybe CoercionPlusHoles) - } + = CH { ch_co_var :: CoVar -- See Note [Coercion holes] wrinkle (COH2) + , ch_ref :: IORef (Maybe CoercionPlusHoles) + } data CoercionPlusHoles = CPH { cph_co :: Coercion @@ -1714,7 +1712,7 @@ instance Data.Data CoercionHole where dataTypeOf _ = mkNoRepType "CoercionHole" instance Outputable CoercionHole where - ppr (CoercionHole { ch_co_var = cv }) = braces (ppr cv) + ppr (CH { ch_co_var = cv }) = braces (ppr cv) instance Outputable CoercionPlusHoles where ppr (CPH { cph_co = co, cph_holes = holes }) @@ -1723,7 +1721,7 @@ instance Outputable CoercionPlusHoles where , text "cph_holes =" <+> ppr holes ]) instance Uniquable CoercionHole where - getUnique (CoercionHole { ch_co_var = cv }) = getUnique cv + getUnique (CH { ch_co_var = cv }) = getUnique cv -- | A CoHoleSet stores a set of CoercionHoles that have been used to rewrite ===================================== compiler/GHC/Core/TyCo/Subst.hs ===================================== @@ -892,8 +892,7 @@ subst_co subst co in cos' `seqList` cos' -- See Note [Substituting in a coercion hole] - go_hole h@(CoercionHole { ch_co_var = cv }) - = h { ch_co_var = updateVarType go_ty cv } + go_hole h@(CH { ch_co_var = cv }) = h { ch_co_var = updateVarType go_ty cv } -- | Perform a substitution within a 'DVarSet' of free variables, -- returning the shallow free coercion variables. ===================================== compiler/GHC/Core/TyCo/Tidy.hs ===================================== @@ -357,7 +357,7 @@ tidyCo env co go_cv cv = tidyTyCoVarOcc env cv - go_hole (CoercionHole cv r) = (CoercionHole $! go_cv cv) r + go_hole (CH cv r) = (CH $! go_cv cv) r -- Tidy even the holes; tidied types should have tidied kinds tidyCos :: TidyEnv -> [Coercion] -> [Coercion] ===================================== compiler/GHC/Tc/Gen/Expr.hs ===================================== @@ -199,6 +199,9 @@ tcPolyExprCheck expr res_ty -> TcM (HsExpr GhcTc) outer_skolemise (Left ty) thing_inside = do { (wrap, expr') <- tcSkolemiseExpectedType ty thing_inside + ; traceTc "outer_skol" (vcat [ text "wrap" <+> ppr wrap + , text "expr'" <+> ppr expr' + , text "wrapped" <+> ppr (mkHsWrap wrap expr') ]) ; return (mkHsWrap wrap expr') } outer_skolemise (Right sig) thing_inside = do { (wrap, expr') <- tcSkolemiseCompleteSig sig thing_inside ===================================== compiler/GHC/Tc/Solver/Default.hs ===================================== @@ -272,10 +272,9 @@ unsatisfiableEv_maybe v = (v,) <$> isUnsatisfiableCt_maybe (idType v) -- solve all the other Wanted constraints, including those nested within -- deeper implications. solveImplicationUsingUnsatGiven :: (EvVar, Type) -> Implication -> TcS Implication -solveImplicationUsingUnsatGiven - unsat_given@(given_ev,_) +solveImplicationUsingUnsatGiven unsat_given impl@(Implic { ic_wanted = wtd, ic_tclvl = tclvl, ic_binds = ev_binds_var - , ic_need_implic = inner, ic_info = skol_info }) + , ic_info = skol_info }) | isCoEvBindsVar ev_binds_var -- We can't use Unsatisfiable evidence in kinds. -- See Note [Coercion evidence only] in GHC.Tc.Types.Evidence. @@ -283,9 +282,7 @@ solveImplicationUsingUnsatGiven | otherwise = do { wcs <- nestImplicTcS skol_info ev_binds_var tclvl $ go_wc wtd ; setImplicationStatus $ - impl { ic_wanted = wcs - , ic_need_implic = inner `extendEvNeedSet` given_ev } } - -- Record that the Given is needed; I'm not certain why + impl { ic_wanted = wcs } } where go_wc :: WantedConstraints -> TcS WantedConstraints go_wc wc@(WC { wc_simple = wtds, wc_impl = impls }) ===================================== compiler/GHC/Tc/Solver/Equality.hs ===================================== @@ -601,7 +601,7 @@ can_eq_nc_forall ev eq_rel s1 s2 -- they are kept alive by `neededEvVars`. Admittedly they are free in `all_co`, -- but only if we zonk it, which `neededEvVars` does not do (see test T7196). ev_binds_var <- getTcEvBindsVar - ; updTcEvBinds ev_binds_var nested_ev_binds_var + ; combineTcEvBinds ev_binds_var nested_ev_binds_var ; setWantedEq orig_dest (CPH { cph_co = all_co, cph_holes = emptyCoHoleSet }) -- emptyCoHoleSet: fully solved, so all_co has no holes ===================================== compiler/GHC/Tc/Solver/Monad.hs ===================================== @@ -15,7 +15,7 @@ module GHC.Tc.Solver.Monad ( failTcS, warnTcS, addErrTcS, wrapTcS, ctLocWarnTcS, runTcSEqualities, nestTcS, nestImplicTcS, tryShortCutTcS, nestFunDepsTcS, - setEvBindsTcS, setTcLevelTcS, updTcEvBinds, + setEvBindsTcS, setTcLevelTcS, selectNextWorkItem, getWorkList, @@ -58,7 +58,7 @@ module GHC.Tc.Solver.Monad ( getInstEnvs, getFamInstEnvs, -- Getting the environments getTopEnv, getGblEnv, getLclEnv, setSrcSpan, getTcEvBindsVar, getTcLevel, - getTcEvTyCoVars, getTcEvBindsMap, setTcEvBindsMap, + getTcEvBindsMap, setTcEvBindsMap, getTcEvBindsState, combineTcEvBinds, tcLookupClass, tcLookupId, tcLookupTyCon, -- Inerts @@ -1140,7 +1140,7 @@ csTraceTcM mk_doc {-# INLINE csTraceTcM #-} -- see Note [INLINE conditional tracing utilities] runTcS :: TcS a -- What to run - -> TcM (a, EvBindMap) + -> TcM (a, EvBindsMap) runTcS tcs = do { ev_binds_var <- TcM.newTcEvBinds ; res <- runTcSWithEvBinds ev_binds_var tcs @@ -1222,7 +1222,7 @@ runTcSWithEvBinds' mode ev_binds_var thing_inside ---------------------------- #if defined(DEBUG) -checkForCyclicBinds :: EvBindMap -> TcM () +checkForCyclicBinds :: EvBindsMap -> TcM () checkForCyclicBinds ev_binds_map | null cycles = return () @@ -1380,18 +1380,24 @@ tryShortCutTcS (TcS thing_inside) , tcs_inerts = new_inert_var , tcs_worklist = new_wl_var } - ; TcM.traceTc "tryTcS {" $ + ; TcM.traceTc "tryShortCutTcS {" $ vcat [ text "old_ev_binds:" <+> ppr old_ev_binds_var , text "new_ev_binds:" <+> ppr new_ev_binds_var , ppr old_inerts ] ; solved <- thing_inside nest_env - ; TcM.traceTc "tryTcS }" (ppr solved) + ; TcM.traceTc "tryShortCutTcS }" (ppr solved) ; if not solved then return False else do { -- Successfully solved -- Add the new bindings to the existing ones - ; TcM.updTcEvBinds old_ev_binds_var new_ev_binds_var + ; old_ebvs <- TcM.readTcRef (ebv_binds old_ev_binds_var) + + ; TcM.combineTcEvBinds old_ev_binds_var new_ev_binds_var + + ; final_ebvs <- TcM.readTcRef (ebv_binds old_ev_binds_var) + ; TcM.traceTc "update" (text "old" <+> ppr old_ebvs $$ + text "new" <+> ppr final_ebvs) -- Update the existing inert set ; new_inerts <- TcM.readTcRef new_inert_var @@ -1465,21 +1471,21 @@ getTcEvBindsVar = TcS (return . tcs_ev_binds) getTcLevel :: TcS TcLevel getTcLevel = wrapTcS TcM.getTcLevel -getTcEvTyCoVars :: EvBindsVar -> TcS [TcCoercion] -getTcEvTyCoVars ev_binds_var - = wrapTcS $ TcM.getTcEvTyCoVars ev_binds_var +getTcEvBindsState :: EvBindsVar -> TcS EvBindsState +getTcEvBindsState ev_binds_var + = wrapTcS $ TcM.getTcEvBindsState ev_binds_var -getTcEvBindsMap :: EvBindsVar -> TcS EvBindMap +getTcEvBindsMap :: EvBindsVar -> TcS EvBindsMap getTcEvBindsMap ev_binds_var = wrapTcS $ TcM.getTcEvBindsMap ev_binds_var -setTcEvBindsMap :: EvBindsVar -> EvBindMap -> TcS () +setTcEvBindsMap :: EvBindsVar -> EvBindsMap -> TcS () setTcEvBindsMap ev_binds_var binds = wrapTcS $ TcM.setTcEvBindsMap ev_binds_var binds -updTcEvBinds :: EvBindsVar -> EvBindsVar -> TcS () -updTcEvBinds evb nested_evb - = wrapTcS $ TcM.updTcEvBinds evb nested_evb +combineTcEvBinds :: EvBindsVar -> EvBindsVar -> TcS () +combineTcEvBinds evb nested_evb + = wrapTcS $ TcM.combineTcEvBinds evb nested_evb getDefaultInfo :: TcS (DefaultEnv, Bool) getDefaultInfo = wrapTcS TcM.tcGetDefaultTys @@ -2029,12 +2035,9 @@ setWantedDict dest canonical tm HoleDest h -> pprPanic "setWantedEq: HoleDest" (ppr h) fillCoercionHole :: CoercionHole -> CoercionPlusHoles -> TcS () -fillCoercionHole hole co_plus_holes@(CPH { cph_co = co }) +fillCoercionHole hole co_plus_holes = do { ev_binds_var <- getTcEvBindsVar - ; wrapTcS $ do { -- Record usage of the free vars of this coercion - TcM.updTcRef (ebv_tcvs ev_binds_var) (co :) - ; -- Fill the hole - TcM.fillCoercionHole hole co_plus_holes } + ; wrapTcS $ TcM.addTcEvCoBind ev_binds_var hole co_plus_holes ; kickOutAfterFillingCoercionHole hole co_plus_holes } newTcEvBinds :: TcS EvBindsVar ===================================== compiler/GHC/Tc/Solver/Solve.hs ===================================== @@ -33,7 +33,6 @@ import qualified GHC.Tc.Zonk.TcType as TcM import GHC.Core.Predicate import GHC.Core.Reduction import GHC.Core.Coercion -import GHC.Core.TyCo.FVs( coVarsOfCos ) import GHC.Core.Class( classHasSCs ) import GHC.Types.Id( idType ) @@ -432,12 +431,10 @@ solveImplication imp@(Implic { ic_tclvl = tclvl , ic_wanted = final_wanted }) ; evbinds <- TcS.getTcEvBindsMap ev_binds_var - ; tcvs <- TcS.getTcEvTyCoVars ev_binds_var ; traceTcS "solveImplication end }" $ vcat [ text "has_given_eqs =" <+> ppr has_given_eqs , text "res_implic =" <+> ppr res_implic - , text "implication evbinds =" <+> ppr (evBindMapBinds evbinds) - , text "implication tvcs =" <+> ppr tcvs ] + , text "evbinds =" <+> ppr evbinds ] ; return res_implic } @@ -460,30 +457,27 @@ setImplicationStatus :: Implication -> TcS Implication -- * Prune unnecessary evidence bindings -- * Prune unnecessary child implications -- Precondition: the ic_status field is not already IC_Solved -setImplicationStatus implic@(Implic { ic_status = old_status - , ic_info = info - , ic_wanted = wc }) - = assertPpr (not (isSolvedStatus old_status)) (ppr info) $ - -- Precondition: we only set the status if it is not already solved - do { traceTcS "setImplicationStatus {" (ppr implic) - - ; let solved = isSolvedWC wc - ; new_implic <- neededEvVars implic - ; bad_telescope <- if solved then checkBadTelescope implic - else return False - - ; let new_status | insolubleWC wc = IC_Insoluble - | not solved = IC_Unsolved - | bad_telescope = IC_BadTelescope - | otherwise = IC_Solved { ics_dead = dead_givens } - dead_givens = findRedundantGivens new_implic - new_wc = pruneImplications wc - - final_implic = new_implic { ic_status = new_status - , ic_wanted = new_wc } - - ; traceTcS "setImplicationStatus }" (ppr final_implic) - ; return final_implic } +setImplicationStatus implic@(Implic { ic_wanted = wc }) + | insolubleWC wc + = do { traceTcS "setImplicationStatus:insoluble {" (ppr implic) + ; return (implic { ic_status = IC_Insoluble }) } + + | not (isSolvedWC wc) + = -- Precondition: we only set the status if it is not /already/ solved + do { traceTcS "setImplicationStatus:in progress {" (ppr implic) + ; return (implic { ic_status = IC_Unsolved }) } + + | otherwise -- The Wanteds are all solved + = do { traceTcS "setImplicationStatus:solved {" (ppr implic) + ; bad_telescope <- checkBadTelescope implic + ; if bad_telescope + then return (implic { ic_status = IC_BadTelescope }) + else + + do { solved_status <- computeSolvedStatus implic + ; let pruned_wc = pruneImplications wc + ; return (implic { ic_status = solved_status + , ic_wanted = pruned_wc }) } } pruneImplications :: WantedConstraints -> WantedConstraints -- We have now recorded the `ic_need` variables of the child @@ -502,8 +496,8 @@ pruneImplications wc@(WC { wc_impl = implics }) | otherwise = True -- Otherwise, keep it -findRedundantGivens :: Implication -> [EvVar] -findRedundantGivens (Implic { ic_info = info, ic_need = need, ic_given = givens }) +findRedundantGivens :: SkolemInfoAnon -> NeededEvIds -> [EvVar] -> [EvVar] +findRedundantGivens info need givens | not (warnRedundantGivens info) -- Don't report redundant constraints at all = [] -- See (TRC4) of Note [Tracking redundant constraints] @@ -520,9 +514,8 @@ findRedundantGivens (Implic { ic_info = info, ic_need = need, ic_given = givens unused_givens = filterOut is_used givens - needed_givens_ignoring_default_methods = ens_fvs need is_used given = is_type_error given - || given `elemVarSet` needed_givens_ignoring_default_methods + || given `elemVarSet` need || (in_instance_decl && is_improving (idType given)) minimal_givens = mkMinimalBySCs evVarPred givens -- See (TRC2) @@ -611,113 +604,105 @@ checkBadTelescope (Implic { ic_info = info | otherwise = go (later_skols `extendVarSet` one_skol) earlier_skols -neededEvVars :: Implication -> TcS Implication --- Find all the evidence variables that are "needed", --- /and/ delete dead evidence bindings +computeSolvedStatus :: Implication -> TcS ImplicStatus +-- Given a fully-solved implication, +-- - Figure out the right IC_Solved fields +-- - Delete unused evidence bindings -- -- See Note [Tracking redundant constraints] -- See Note [Delete dead Given evidence bindings] --- --- - Start from initial_seeds (from nested implications) --- --- - Add free vars of RHS of all Wanted evidence bindings --- and coercion variables accumulated in tcvs (all Wanted) --- --- - Generate 'needed', the needed set of EvVars, by doing transitive --- closure through Given bindings --- e.g. Needed {a,b} --- Given a = sc_sel a2 --- Then a2 is needed too --- --- - Prune out all Given bindings that are not needed - -neededEvVars implic@(Implic { ic_info = info +computeSolvedStatus (Implic { ic_info = info , ic_binds = ev_binds_var - , ic_wanted = WC { wc_impl = implics } - , ic_need_implic = old_need_implic -- See (TRC1) - }) - = do { ev_binds <- TcS.getTcEvBindsMap ev_binds_var - ; used_cos <- TcS.getTcEvTyCoVars ev_binds_var - - ; let -- Find the variables needed by `implics` - new_need_implic@(ENS { ens_dms = dm_seeds, ens_fvs = other_seeds }) - = foldr add_implic old_need_implic implics - -- Start from old_need_implic! See (TRC1) - - -- Get the variables needed by the solved bindings - -- (It's OK to use a non-deterministic fold here - -- because add_wanted is commutative.) - used_covars = coVarsOfCos used_cos - seeds_w = nonDetStrictFoldEvBindMap add_wanted used_covars ev_binds - - need_ignoring_dms = findNeededGivenEvVars ev_binds (other_seeds `unionVarSet` seeds_w) - need_from_dms = findNeededGivenEvVars ev_binds dm_seeds - need_full = need_ignoring_dms `unionVarSet` need_from_dms - - -- `need`: the Givens from outer scopes that are used in this implication - -- is_dm_skol: see (TRC5) - need | is_dm_skol info = ENS { ens_dms = trim ev_binds need_full - , ens_fvs = emptyVarSet } - | otherwise = ENS { ens_dms = trim ev_binds need_from_dms - , ens_fvs = trim ev_binds need_ignoring_dms } - - -- Delete dead Given evidence bindings + , ic_given = givens + , ic_wanted = WC { wc_impl = implics } }) + = do { ev_binds_state <- TcS.getTcEvBindsState ev_binds_var + + ; let EBS { ebs_binds = ev_binds, ebs_needs = local_needs } = ev_binds_state + + -- Gather the raw needed EvIds, from the + -- current evidence bindings `local_needs`, and the `implics` + (need_dm, need_non_dm) = foldr add_implic (emptyVarSet, local_needs) implics + + -- Do transitive closure through the evidence bindings + -- and delete all EvIds bound by the bindings + need_dm1 = findNeededGivenEvVars ev_binds need_dm + need_non_dm1 = findNeededGivenEvVars ev_binds need_non_dm + + -- Compute the redundant Givens + dead_givens = findRedundantGivens info need_non_dm1 givens + + -- Delete variables bound by ev_binds or by givens + need_dm2 = trim_needs need_dm1 + need_non_dm2 = trim_needs need_non_dm1 + + trim_needs :: NeededEvIds -> NeededEvIds + trim_needs needs = (needs `varSetMinusEvBindsMap` ev_binds) + `delVarSetList` givens + + -- Prune dead Given evidence bindings -- See Note [Delete dead Given evidence bindings] - ; let live_ev_binds = filterEvBindMap (needed_ev_bind need_full) ev_binds - ; TcS.setTcEvBindsMap ev_binds_var live_ev_binds - - ; traceTcS "neededEvVars" $ - vcat [ text "old_need_implic:" <+> ppr old_need_implic - , text "new_need_implic:" <+> ppr new_need_implic - , text "used_covars:" <+> ppr used_covars - , text "need_ignoring_dms:" <+> ppr need_ignoring_dms - , text "need_from_dms:" <+> ppr need_from_dms - , text "need:" <+> ppr need + ; let need_full = need_dm1 `unionVarSet` need_non_dm1 + pruned_ev_binds = filterEvBindsMap (keep_ev_bind need_full) ev_binds + ; TcS.setTcEvBindsMap ev_binds_var pruned_ev_binds + + ; traceTcS "computeSolvedStatus" $ + vcat [ text "local_needs:" <+> ppr local_needs + , text "need_dm:" <+> ppr need_dm + , text "need_non_dm:" <+> ppr need_non_dm + , text "need_dm1:" <+> ppr need_dm1 + , text "need_non_dm1:" <+> ppr need_non_dm1 + , text "need_dm2:" <+> ppr need_dm2 + , text "need_non_dm2:" <+> ppr need_non_dm2 , text "ev_binds:" <+> ppr ev_binds - , text "live_ev_binds:" <+> ppr live_ev_binds ] - ; return (implic { ic_need = need - , ic_need_implic = new_need_implic }) } - where - trim :: EvBindMap -> VarSet -> VarSet - -- Delete variables bound by Givens or bindings - trim ev_binds needs = needs `varSetMinusEvBindMap` ev_binds + , text "deleted ev_binds:" + <+> ppr (filterEvBindsMap (not . keep_ev_bind need_full) ev_binds) ] - add_implic :: Implication -> EvNeedSet -> EvNeedSet - add_implic (Implic { ic_given = givens, ic_need = need }) acc - = (need `delGivensFromEvNeedSet` givens) `unionEvNeedSet` acc + ; if is_dm_skol info + then return (IC_Solved { ics_dead = dead_givens + , ics_dm = need_dm2 `unionVarSet` need_non_dm2 + , ics_non_dm = emptyVarSet }) - needed_ev_bind needed (EvBind { eb_lhs = ev_var, eb_info = info }) + else return (IC_Solved { ics_dead = dead_givens + , ics_dm = need_dm2 + , ics_non_dm = need_non_dm2 }) } + where + add_implic :: Implication -> (NeededEvIds, NeededEvIds) -> (NeededEvIds, NeededEvIds) + add_implic (Implic { ic_status = status}) (dm2, non_dm2) + | IC_Solved { ics_dm = dm1, ics_non_dm = non_dm1 } <- status + = (dm1 `unionVarSet` dm2, non_dm1 `unionVarSet` non_dm2) + | otherwise + = pprPanic "computeSolvedStatus" (ppr implics) + + keep_ev_bind :: NeededEvIds -> EvBind -> Bool + -- False => we can discard this unused Given evidence binding + -- We always keep all the Wanted bindings + keep_ev_bind needed (EvBind { eb_lhs = ev_var, eb_info = info }) | EvBindGiven{} <- info = ev_var `elemVarSet` needed | otherwise = True -- Keep all wanted bindings - add_wanted :: EvBind -> VarSet -> VarSet - add_wanted (EvBind { eb_info = info, eb_rhs = rhs }) needs - | EvBindGiven{} <- info = needs -- Add the rhs vars of the Wanted bindings only - | otherwise = nestedEvIdsOfTerm rhs `unionVarSet` needs - is_dm_skol :: SkolemInfoAnon -> Bool is_dm_skol (MethSkol _ is_dm) = is_dm is_dm_skol _ = False -findNeededGivenEvVars :: EvBindMap -> VarSet -> VarSet +findNeededGivenEvVars :: EvBindsMap -> NeededEvIds -> NeededEvIds -- Find all the Given evidence needed by seeds, -- looking transitively through bindings for Givens (only) findNeededGivenEvVars ev_binds seeds = transCloVarSet also_needs seeds where - also_needs :: VarSet -> VarSet - also_needs needs = nonDetStrictFoldUniqSet add emptyVarSet needs - -- It's OK to use a non-deterministic fold here because we immediately - -- forget about the ordering by creating a set - - add :: Var -> VarSet -> VarSet - add v needs - | Just ev_bind <- lookupEvBind ev_binds v - , EvBind { eb_info = EvBindGiven, eb_rhs = rhs } <- ev_bind - -- Look at Given bindings only - = nestedEvIdsOfTerm rhs `unionVarSet` needs - | otherwise - = needs + also_needs :: VarSet -> VarSet + also_needs needs = nonDetStrictFoldUniqSet add emptyVarSet needs + -- It's OK to use a non-deterministic fold here because we immediately + -- forget about the ordering by creating a set + + add :: Var -> VarSet -> VarSet + add v needs + | Just ev_bind <- lookupEvBind ev_binds v + , EvBind { eb_info = EvBindGiven, eb_rhs = rhs } <- ev_bind + -- Look at Given bindings only + = nestedEvIdsOfTerm rhs `unionVarSet` needs + | otherwise + = needs ------------------------------------------------- simplifyDelayedErrors :: Bag DelayedError -> TcS (Bag DelayedError) @@ -949,7 +934,7 @@ Wrinkles: and because of the degnerate instance for `Show (T a)`, we don't need the `Eq a` constraint. But we don't want to report it as redundant! -(TRC5) Consider this (#25992), where `op2` has a default method +(TRC5) Default methods. Consider this (#25992), where `op2` has a default method class C a where { op1, op2 :: a -> a ; op2 = op1 . op1 } instance C a => C [a] where @@ -960,10 +945,12 @@ Wrinkles: $dmop2 = op1 . op1 $fCList :: forall a. C a => C [a] - $fCList @a (d::C a) = MkC (\(x:a).x) ($dmop2 @a d) + $fCList @a (d::C a) = MkC (\(x:a).x) + ($dmop2 @[a] ($fCList @a d)) - Notice that `d` gets passed to `$dmop`: it is "needed". But it's only - /really/ needed if some /other/ method (in this case `op1`) uses it. + Notice that `d` gets passed, indirectly to `$dmop`: it appears to be + "needed". But it's only /really/ needed if some /other/ method or + superclass (in this case `op1`) uses it. So, rather than one set of "needed Givens" we use `EvNeedSet` to track a /pair/ of sets: @@ -1645,10 +1632,12 @@ solveWantedQCI mode ct@(CQuantCan (QCI { qci_ev = ev, qci_tvs = tvs -- carrying a record of which evidence variables are used -- See Note [Free vars of EvFun] in GHC.Tc.Types.Evidence do { setWantedDict dest EvCanonical $ - EvFun { et_tvs = skol_tvs, et_given = given_ev_vars + EvFun { et_tvs = skol_tvs + , et_given = given_ev_vars , et_binds = TcEvBinds ev_binds_var - , et_body = wantedCtEvEvId wanted_ev } + , et_body = wantedCtEvEvId wanted_ev } + ; traceTcS "solveWantedQCI" (ppr imp') ; return (Right imp') } } ===================================== compiler/GHC/Tc/Types/Constraint.hs ===================================== @@ -65,7 +65,6 @@ module GHC.Tc.Types.Constraint ( ImplicStatus(..), isInsolubleStatus, isSolvedStatus, UserGiven, getGivensFromImplics, HasGivenEqs(..), checkImplicationInvariants, - EvNeedSet(..), emptyEvNeedSet, unionEvNeedSet, extendEvNeedSet, delGivensFromEvNeedSet, -- CtLocEnv CtLocEnv(..), setCtLocEnvLoc, setCtLocEnvLvl, getCtLocEnvLoc, getCtLocEnvLvl, ctLocEnvInGeneratedCode, @@ -1564,45 +1563,9 @@ data Implication ic_binds :: EvBindsVar, -- Points to the place to fill in the -- abstraction and bindings. - -- The ic_need fields keep track of which Given evidence - -- is used by this implication or its children - -- See Note [Tracking redundant constraints] - -- NB: these sets include stuff used by fully-solved nested implications - -- that have since been discarded - ic_need :: EvNeedSet, -- All needed Given evidence, from this implication - -- or outer ones - -- That is, /after/ deleting the binders of ic_binds, - -- but /before/ deleting ic_givens - - ic_need_implic :: EvNeedSet, -- Union of of the ic_need of all implications in ic_wanted - -- /including/ any fully-solved implications that have been - -- discarded by `pruneImplications`. This discarding is why - -- we need to keep this field in the first place. - ic_status :: ImplicStatus } -data EvNeedSet = ENS { ens_dms :: VarSet -- Needed only by default methods - , ens_fvs :: VarSet -- Needed by things /other than/ default methods - -- See (TRC5) in Note [Tracking redundant constraints] - } - -emptyEvNeedSet :: EvNeedSet -emptyEvNeedSet = ENS { ens_dms = emptyVarSet, ens_fvs = emptyVarSet } - -unionEvNeedSet :: EvNeedSet -> EvNeedSet -> EvNeedSet -unionEvNeedSet (ENS { ens_dms = dm1, ens_fvs = fv1 }) - (ENS { ens_dms = dm2, ens_fvs = fv2 }) - = ENS { ens_dms = dm1 `unionVarSet` dm2, ens_fvs = fv1 `unionVarSet` fv2 } - -extendEvNeedSet :: EvNeedSet -> Var -> EvNeedSet -extendEvNeedSet ens@(ENS { ens_fvs = fvs }) v = ens { ens_fvs = fvs `extendVarSet` v } - -delGivensFromEvNeedSet :: EvNeedSet -> [Var] -> EvNeedSet -delGivensFromEvNeedSet (ENS { ens_dms = dms, ens_fvs = fvs }) givens - = ENS { ens_dms = dms `delVarSetList` givens - , ens_fvs = fvs `delVarSetList` givens } - implicationPrototype :: CtLocEnv -> Implication implicationPrototype ct_loc_env = Implic { -- These fields must be initialised @@ -1619,14 +1582,21 @@ implicationPrototype ct_loc_env , ic_given = [] , ic_wanted = emptyWC , ic_given_eqs = MaybeGivenEqs - , ic_status = IC_Unsolved - , ic_need = emptyEvNeedSet - , ic_need_implic = emptyEvNeedSet } + , ic_status = IC_Unsolved } data ImplicStatus = IC_Solved -- All wanteds in the tree are solved, all the way down - { ics_dead :: [EvVar] } -- Subset of ic_given that are not needed - -- See Note [Tracking redundant constraints] in GHC.Tc.Solver + { ics_dead :: [EvVar] -- Subset of ic_given that are not needed + + , ics_dm :: NeededEvIds -- Enclosing Given EvIds that are needed by + -- calls to default methods (typically empty) + + , ics_non_dm :: NeededEvIds -- Enclosing Given EvIds that are needed, other than + -- calls to default methods + } + -- Reporting redundant givens: use ics_non_dm + -- Pruning evidence bindings: use ics_dm `union` ics_non_dm + -- See Note [Tracking redundant constraints] in GHC.Tc.Solver | IC_Insoluble -- At least one insoluble Wanted constraint in the tree @@ -1715,7 +1685,6 @@ instance Outputable Implication where , ic_given = given, ic_given_eqs = given_eqs , ic_wanted = wanted, ic_status = status , ic_binds = binds - , ic_need = need, ic_need_implic = need_implic , ic_info = info }) = hang (text "Implic" <+> lbrace) 2 (sep [ text "TcLevel =" <+> ppr tclvl @@ -1725,21 +1694,17 @@ instance Outputable Implication where , hang (text "Given =") 2 (pprEvVars given) , hang (text "Wanted =") 2 (ppr wanted) , text "Binds =" <+> ppr binds - , text "need =" <+> ppr need - , text "need_implic =" <+> ppr need_implic , pprSkolInfo info ] <+> rbrace) -instance Outputable EvNeedSet where - ppr (ENS { ens_dms = dms, ens_fvs = fvs }) - = text "ENS" <> braces (sep [text "ens_dms =" <+> ppr dms - , text "ens_fvs =" <+> ppr fvs]) - instance Outputable ImplicStatus where ppr IC_Insoluble = text "Insoluble" ppr IC_BadTelescope = text "Bad telescope" ppr IC_Unsolved = text "Unsolved" - ppr (IC_Solved { ics_dead = dead }) - = text "Solved" <+> (braces (text "Dead givens =" <+> ppr dead)) + ppr (IC_Solved { ics_dead = dead, ics_dm = dm, ics_non_dm = non_dm }) + = text "Solved" <> (braces $ + vcat [ text "Dead givens =" <+> ppr dead + , text "need_dm =" <+> ppr dm + , text "need_non_dm =" <+> ppr non_dm ]) checkTelescopeSkol :: SkolemInfoAnon -> Bool -- See Note [Checking telescopes] ===================================== compiler/GHC/Tc/Types/Evidence.hs ===================================== @@ -14,14 +14,15 @@ module GHC.Tc.Types.Evidence ( optSubTypeHsWrapper, -- * Evidence bindings - TcEvBinds(..), EvBindsVar(..), - EvBindMap(..), emptyEvBindMap, extendEvBinds, unionEvBindMap, + TcEvBinds(..), EvBindsVar(..), NeededEvIds, + EvBindsState(..), emptyEvBindsState, unionEvBindsState, addCoVarsEBS, + EvBindsMap(..), emptyEvBindsMap, extendEvBinds, unionEvBindsMap, lookupEvBind, evBindMapBinds, - foldEvBindMap, nonDetStrictFoldEvBindMap, - filterEvBindMap, - isEmptyEvBindMap, + foldEvBindsMap, nonDetStrictFoldEvBindsMap, + filterEvBindsMap, + isEmptyEvBindsMap, evBindMapToVarSet, - varSetMinusEvBindMap, + varSetMinusEvBindsMap, EvBindInfo(..), EvBind(..), emptyTcEvBinds, isEmptyTcEvBinds, mkGivenEvBind, mkWantedEvBind, evBindVar, isCoEvBindsVar, @@ -725,12 +726,12 @@ data EvBindsVar ebv_uniq :: Unique, -- The Unique is for debug printing only - ebv_binds :: IORef EvBindMap, + ebv_binds :: IORef EvBindsState -- The main payload: the value-level evidence bindings -- (dictionaries etc) -- Some Given, some Wanted - ebv_tcvs :: IORef [TcCoercion] +-- ebv_needs :: IORef VarSet -- When we solve a Wanted by filling in a CoercionHole, it is as -- if we were adding an evidence binding -- co_hole := coercion @@ -745,10 +746,35 @@ data EvBindsVar | CoEvBindsVar { -- See Note [Coercion evidence only] -- See above for comments on ebv_uniq, ebv_tcvs - ebv_uniq :: Unique, - ebv_tcvs :: IORef [TcCoercion] + ebv_uniq :: Unique, + ebv_needs :: IORef NeededEvIds } +type NeededEvIds = VarSet + +data EvBindsState = EBS { ebs_binds :: EvBindsMap + , ebs_needs :: NeededEvIds } + +emptyEvBindsState :: EvBindsState +emptyEvBindsState = EBS { ebs_binds = emptyEvBindsMap + , ebs_needs = emptyVarSet } + +unionEvBindsState :: EvBindsState -> EvBindsState -> EvBindsState +unionEvBindsState (EBS { ebs_binds = bs1, ebs_needs = n1 }) + (EBS { ebs_binds = bs2, ebs_needs = n2 }) + = EBS { ebs_binds = bs1 `unionEvBindsMap` bs2 + , ebs_needs = n1 `unionVarSet` n2 } + +addCoVarsEBS :: VarSet -> EvBindsState -> EvBindsState +addCoVarsEBS n1 ebs@(EBS { ebs_needs = n2 }) + = ebs { ebs_needs = n1 `unionVarSet` n2 } + +instance Outputable EvBindsState where + ppr (EBS { ebs_binds = bs, ebs_needs = needs }) + = text "EBS" <> (braces $ + sep [ text "needs =" <+> ppr needs + , text "binds =" <+> ppr bs ]) + instance Data.Data TcEvBinds where -- Placeholder; we can't traverse into TcEvBinds toConstr _ = abstractConstr "TcEvBinds" @@ -778,8 +804,8 @@ isCoEvBindsVar (CoEvBindsVar {}) = True isCoEvBindsVar (EvBindsVar {}) = False ----------------- -newtype EvBindMap - = EvBindMap { +newtype EvBindsMap + = EvBindsMap { ev_bind_varenv :: DVarEnv EvBind } -- Map from evidence variables to evidence terms -- We use @DVarEnv@ here to get deterministic ordering when we @@ -801,50 +827,50 @@ newtype EvBindMap -- See Note [Deterministic UniqFM] in GHC.Types.Unique.DFM for explanation why -- @UniqFM@ can lead to nondeterministic order. -emptyEvBindMap :: EvBindMap -emptyEvBindMap = EvBindMap { ev_bind_varenv = emptyDVarEnv } +emptyEvBindsMap :: EvBindsMap +emptyEvBindsMap = EvBindsMap { ev_bind_varenv = emptyDVarEnv } -extendEvBinds :: EvBindMap -> EvBind -> EvBindMap +extendEvBinds :: EvBindsMap -> EvBind -> EvBindsMap extendEvBinds bs ev_bind - = EvBindMap { ev_bind_varenv = extendDVarEnv (ev_bind_varenv bs) + = EvBindsMap { ev_bind_varenv = extendDVarEnv (ev_bind_varenv bs) (eb_lhs ev_bind) ev_bind } -- | Union two evidence binding maps -unionEvBindMap :: EvBindMap -> EvBindMap -> EvBindMap -unionEvBindMap (EvBindMap env1) (EvBindMap env2) = - EvBindMap { ev_bind_varenv = plusDVarEnv env1 env2 } +unionEvBindsMap :: EvBindsMap -> EvBindsMap -> EvBindsMap +unionEvBindsMap (EvBindsMap env1) (EvBindsMap env2) = + EvBindsMap { ev_bind_varenv = plusDVarEnv env1 env2 } -isEmptyEvBindMap :: EvBindMap -> Bool -isEmptyEvBindMap (EvBindMap m) = isEmptyDVarEnv m +isEmptyEvBindsMap :: EvBindsMap -> Bool +isEmptyEvBindsMap (EvBindsMap m) = isEmptyDVarEnv m -lookupEvBind :: EvBindMap -> EvVar -> Maybe EvBind +lookupEvBind :: EvBindsMap -> EvVar -> Maybe EvBind lookupEvBind bs = lookupDVarEnv (ev_bind_varenv bs) -evBindMapBinds :: EvBindMap -> Bag EvBind -evBindMapBinds = foldEvBindMap consBag emptyBag +evBindMapBinds :: EvBindsMap -> Bag EvBind +evBindMapBinds = foldEvBindsMap consBag emptyBag -foldEvBindMap :: (EvBind -> a -> a) -> a -> EvBindMap -> a -foldEvBindMap k z bs = foldDVarEnv k z (ev_bind_varenv bs) +foldEvBindsMap :: (EvBind -> a -> a) -> a -> EvBindsMap -> a +foldEvBindsMap k z bs = foldDVarEnv k z (ev_bind_varenv bs) -- See Note [Deterministic UniqFM] to learn about nondeterminism. -- If you use this please provide a justification why it doesn't introduce -- nondeterminism. -nonDetStrictFoldEvBindMap :: (EvBind -> a -> a) -> a -> EvBindMap -> a -nonDetStrictFoldEvBindMap k z bs = nonDetStrictFoldDVarEnv k z (ev_bind_varenv bs) +nonDetStrictFoldEvBindsMap :: (EvBind -> a -> a) -> a -> EvBindsMap -> a +nonDetStrictFoldEvBindsMap k z bs = nonDetStrictFoldDVarEnv k z (ev_bind_varenv bs) -filterEvBindMap :: (EvBind -> Bool) -> EvBindMap -> EvBindMap -filterEvBindMap k (EvBindMap { ev_bind_varenv = env }) - = EvBindMap { ev_bind_varenv = filterDVarEnv k env } +filterEvBindsMap :: (EvBind -> Bool) -> EvBindsMap -> EvBindsMap +filterEvBindsMap k (EvBindsMap { ev_bind_varenv = env }) + = EvBindsMap { ev_bind_varenv = filterDVarEnv k env } -evBindMapToVarSet :: EvBindMap -> VarSet -evBindMapToVarSet (EvBindMap dve) = unsafeUFMToUniqSet (mapUFM evBindVar (udfmToUfm dve)) +evBindMapToVarSet :: EvBindsMap -> VarSet +evBindMapToVarSet (EvBindsMap dve) = unsafeUFMToUniqSet (mapUFM evBindVar (udfmToUfm dve)) -varSetMinusEvBindMap :: VarSet -> EvBindMap -> VarSet -varSetMinusEvBindMap vs (EvBindMap dve) = vs `uniqSetMinusUDFM` dve +varSetMinusEvBindsMap :: VarSet -> EvBindsMap -> VarSet +varSetMinusEvBindsMap vs (EvBindsMap dve) = vs `uniqSetMinusUDFM` dve -instance Outputable EvBindMap where - ppr (EvBindMap m) = ppr m +instance Outputable EvBindsMap where + ppr (EvBindsMap m) = ppr m data EvBindInfo = EvBindGiven { -- See Note [Tracking redundant constraints] in GHC.Tc.Solver ===================================== compiler/GHC/Tc/Utils/Monad.hs ===================================== @@ -104,9 +104,10 @@ module GHC.Tc.Utils.Monad( -- * Type constraints newTcEvBinds, newNoTcEvBinds, cloneEvBindsVar, - addTcEvBind, addTcEvBinds, addTopEvBinds, - getTcEvBindsMap, setTcEvBindsMap, updTcEvBinds, - getTcEvTyCoVars, chooseUniqueOccTc, + addTcEvCoBind, addTcEvBind, addTopEvBinds, + getTcEvBindsMap, getTcEvBindsState, + setTcEvBindsMap, combineTcEvBinds, + chooseUniqueOccTc, getConstraintVar, setConstraintVar, emitConstraints, emitSimple, emitSimples, emitImplication, emitImplications, ensureReflMultiplicityCo, @@ -118,6 +119,7 @@ module GHC.Tc.Utils.Monad( getLclTypeEnv, setLclTypeEnv, traceTcConstraints, emitNamedTypeHole, IsExtraConstraint(..), emitAnonTypeHole, + fillCoercionHole, -- * Template Haskell context recordThUse, recordThNeededRuntimeDeps, @@ -187,12 +189,13 @@ import GHC.Unit.Module.Warnings import GHC.Unit.Home.PackageTable import GHC.Core.UsageEnv - import GHC.Core.Coercion ( isReflCo ) import GHC.Core.Multiplicity import GHC.Core.InstEnv import GHC.Core.FamInstEnv import GHC.Core.Type( mkNumLitTy ) +import GHC.Core.TyCo.Rep( CoercionHole(..) ) +import GHC.Core.TyCo.FVs( coVarsOfCo ) import GHC.Core.TyCon ( TyCon ) import GHC.Driver.Env @@ -230,6 +233,7 @@ import GHC.Types.SafeHaskell import GHC.Types.Id import GHC.Types.TypeEnv import GHC.Types.Var.Env +import GHC.Types.Var.Set import GHC.Types.SrcLoc import GHC.Types.Name.Env import GHC.Types.Name.Set @@ -1660,6 +1664,105 @@ tryTcDiscardingErrs' validate recover_invalid recover_error thing_inside recover_error } +{- Note [Constraints and errors] +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +Consider this (#12124): + + foo :: Maybe Int + foo = return (case Left 3 of + Left -> 1 -- Hard error here! + _ -> 0) + +The call to 'return' will generate a (Monad m) wanted constraint; but +then there'll be "hard error" (i.e. an exception in the TcM monad), from +the unsaturated Left constructor pattern. + +We'll recover in tcPolyBinds, using recoverM. But then the final +tcSimplifyTop will see that (Monad m) constraint, with 'm' utterly +un-filled-in, and will emit a misleading error message. + +The underlying problem is that an exception interrupts the constraint +gathering process. Bottom line: if we have an exception, it's best +simply to discard any gathered constraints. Hence in 'attemptM' we +capture the constraints in a fresh variable, and only emit them into +the surrounding context if we exit normally. If an exception is +raised, simply discard the collected constraints... we have a hard +error to report. So this capture-the-emit dance isn't as stupid as it +looks :-). + +However suppose we throw an exception inside an invocation of +captureConstraints, and discard all the constraints. Some of those +constraints might be "variable out of scope" Hole constraints, and that +might have been the actual original cause of the exception! For +example (#12529): + f = p @ Int +Here 'p' is out of scope, so we get an insoluble Hole constraint. But +the visible type application fails in the monad (throws an exception). +We must not discard the out-of-scope error. + +It's distressingly delicate though: + +* If we discard too /many/ constraints we may fail to report the error + that led us to interrupt the constraint gathering process. + + One particular example "variable out of scope" Hole constraints. For + example (#12529): + f = p @ Int + Here 'p' is out of scope, so we get an insoluble Hole constraint. But + the visible type application fails in the monad (throws an exception). + We must not discard the out-of-scope error. + + Also GHC.Tc.Solver.simplifyAndEmitFlatConstraints may fail having + emitted some constraints with skolem-escape problems. + +* If we discard too /few/ constraints, we may get the misleading + class constraints mentioned above. + + We may /also/ end up taking constraints built at some inner level, and + emitting them (via the exception catching in `tryCaptureConstraints`) at some + outer level, and then breaking the TcLevel invariants See Note [TcLevel + invariants] in GHC.Tc.Utils.TcType + +So `dropMisleading` has a horridly ad-hoc structure: + +* It keeps only /insoluble/ flat constraints (which are unlikely to very visibly + trip up on the TcLevel invariant) + +* But it keeps all /implication/ constraints (except the class constraints + inside them). The implication constraints are OK because they set the ambient + level before attempting to solve any inner constraints. + +Ugh! I hate this. But it seems to work. + +Other wrinkles + +(CERR1) Note that freshly-generated constraints like (Int ~ Bool), or + ((a -> b) ~ Int) are all CNonCanonical, and hence won't be flagged as + insoluble. The constraint solver does that. So they'll be discarded. + That's probably ok; but see th/5358 as a not-so-good example: + t1 :: Int + t1 x = x -- Manifestly wrong + + foo = $(...raises exception...) + We report the exception, but not the bug in t1. Oh well. Possible + solution: make GHC.Tc.Utils.Unify.uType spot manifestly-insoluble constraints. + +(CERR2) In #26015 I found that from the constraints + [W] alpha ~ Int -- A class constraint + [W] F alpha ~# Bool -- An equality constraint + we were dropping the first (becuase it's a class constraint) but not the + second, and then getting a misleading error message from the second. As + #25607 shows, we can get not just one but a zillion bogus messages, which + conceal the one genuine error. Boo. + + For now I have added an even more ad-hoc "drop class constraints except + equality classes (~) and (~~)"; see `dropMisleading`. That just kicks the can + down the road; but this problem seems somewhat rare anyway. The code in + `dropMisleading` hasn't changed for years. + +It would be great to have a more systematic solution to this entire mess. +-} + {- ************************************************************************ * * @@ -1854,108 +1957,112 @@ debugTc thing addTopEvBinds :: Bag EvBind -> TcM a -> TcM a addTopEvBinds new_ev_binds thing_inside - =updGblEnv upd_env thing_inside + = updGblEnv upd_env thing_inside where upd_env tcg_env = tcg_env { tcg_ev_binds = tcg_ev_binds tcg_env `unionBags` new_ev_binds } newTcEvBinds :: TcM EvBindsVar -newTcEvBinds = do { binds_ref <- newTcRef emptyEvBindMap - ; tcvs_ref <- newTcRef [] +newTcEvBinds = do { binds_ref <- newTcRef emptyEvBindsState ; uniq <- newUnique ; traceTc "newTcEvBinds" (text "unique =" <+> ppr uniq) ; return (EvBindsVar { ebv_binds = binds_ref - , ebv_tcvs = tcvs_ref , ebv_uniq = uniq }) } -- | Creates an EvBindsVar incapable of holding any bindings. It still --- tracks covar usages (see comments on ebv_tcvs in "GHC.Tc.Types.Evidence"), thus +-- tracks covar usages (see comments on ebv_needs in "GHC.Tc.Types.Evidence"), thus -- must be made monadically newNoTcEvBinds :: TcM EvBindsVar newNoTcEvBinds - = do { tcvs_ref <- newTcRef [] + = do { tcvs_ref <- newTcRef emptyVarSet ; uniq <- newUnique ; traceTc "newNoTcEvBinds" (text "unique =" <+> ppr uniq) - ; return (CoEvBindsVar { ebv_tcvs = tcvs_ref - , ebv_uniq = uniq }) } + ; return (CoEvBindsVar { ebv_needs = tcvs_ref + , ebv_uniq = uniq }) } cloneEvBindsVar :: EvBindsVar -> TcM EvBindsVar -- Clone the refs, so that any binding created when -- solving don't pollute the original cloneEvBindsVar ebv@(EvBindsVar {}) - = do { binds_ref <- newTcRef emptyEvBindMap - ; tcvs_ref <- newTcRef [] - ; return (ebv { ebv_binds = binds_ref - , ebv_tcvs = tcvs_ref }) } + = do { binds_ref <- newTcRef emptyEvBindsState + ; uniq <- newUnique + ; return (ebv { ebv_uniq = uniq + , ebv_binds = binds_ref }) } cloneEvBindsVar ebv@(CoEvBindsVar {}) - = do { tcvs_ref <- newTcRef [] - ; return (ebv { ebv_tcvs = tcvs_ref }) } + = do { tcvs_ref <- newTcRef emptyVarSet + ; return (ebv { ebv_needs = tcvs_ref }) } -getTcEvTyCoVars :: EvBindsVar -> TcM [TcCoercion] -getTcEvTyCoVars ev_binds_var - = readTcRef (ebv_tcvs ev_binds_var) +getTcEvBindsMap :: EvBindsVar -> TcM EvBindsMap +getTcEvBindsMap ebv = do { EBS { ebs_binds = bs } <- getTcEvBindsState ebv + ; return bs } -getTcEvBindsMap :: EvBindsVar -> TcM EvBindMap -getTcEvBindsMap (EvBindsVar { ebv_binds = ev_ref }) +getTcEvBindsState :: EvBindsVar -> TcM EvBindsState +getTcEvBindsState (EvBindsVar { ebv_binds = ev_ref }) = readTcRef ev_ref -getTcEvBindsMap (CoEvBindsVar {}) - = return emptyEvBindMap - -setTcEvBindsMap :: EvBindsVar -> EvBindMap -> TcM () -setTcEvBindsMap (EvBindsVar { ebv_binds = ev_ref }) binds - = writeTcRef ev_ref binds -setTcEvBindsMap v@(CoEvBindsVar {}) ev_binds - | isEmptyEvBindMap ev_binds - = return () - | otherwise - = pprPanic "setTcEvBindsMap" (ppr v $$ ppr ev_binds) - -updTcEvBinds :: EvBindsVar -> EvBindsVar -> TcM () -updTcEvBinds (EvBindsVar { ebv_binds = old_ebv_ref, ebv_tcvs = old_tcv_ref }) - (EvBindsVar { ebv_binds = new_ebv_ref, ebv_tcvs = new_tcv_ref }) +getTcEvBindsState (CoEvBindsVar { ebv_needs = needs_ref }) + = do { needs <- readTcRef needs_ref + ; return (EBS { ebs_binds = emptyEvBindsMap, ebs_needs = needs }) } + +setTcEvBindsMap :: EvBindsVar -> EvBindsMap -> TcM () +setTcEvBindsMap (EvBindsVar { ebv_binds = ev_ref }) ev_binds + = updTcRef ev_ref (\ebs -> ebs { ebs_binds = ev_binds }) +setTcEvBindsMap (CoEvBindsVar {}) ev_binds + = assertPpr (isEmptyEvBindsMap ev_binds) (ppr ev_binds) $ + return () + +combineTcEvBinds :: EvBindsVar -> EvBindsVar -> TcM () +combineTcEvBinds (EvBindsVar { ebv_binds = old_ebv_ref }) + (EvBindsVar { ebv_binds = new_ebv_ref }) = do { new_ebvs <- readTcRef new_ebv_ref - ; updTcRef old_ebv_ref (`unionEvBindMap` new_ebvs) - ; new_tcvs <- readTcRef new_tcv_ref - ; updTcRef old_tcv_ref (new_tcvs ++) } -updTcEvBinds (EvBindsVar { ebv_tcvs = old_tcv_ref }) - (CoEvBindsVar { ebv_tcvs = new_tcv_ref }) + ; updTcRef old_ebv_ref (`unionEvBindsState` new_ebvs) } +combineTcEvBinds (EvBindsVar { ebv_binds = old_tcv_ref }) + (CoEvBindsVar { ebv_needs = new_tcv_ref }) = do { new_tcvs <- readTcRef new_tcv_ref - ; updTcRef old_tcv_ref (new_tcvs ++) } -updTcEvBinds (CoEvBindsVar { ebv_tcvs = old_tcv_ref }) - (CoEvBindsVar { ebv_tcvs = new_tcv_ref }) + ; updTcRef old_tcv_ref (addCoVarsEBS new_tcvs) } +combineTcEvBinds (CoEvBindsVar { ebv_needs = old_tcv_ref }) + (CoEvBindsVar { ebv_needs = new_tcv_ref }) = do { new_tcvs <- readTcRef new_tcv_ref - ; updTcRef old_tcv_ref (new_tcvs ++) } -updTcEvBinds old_var new_var - = pprPanic "updTcEvBinds" (ppr old_var $$ ppr new_var) + ; updTcRef old_tcv_ref (unionVarSet new_tcvs) } +combineTcEvBinds old_var new_var + = pprPanic "combineTcEvBinds" (ppr old_var $$ ppr new_var) -- Terms inside types, no good +addTcEvCoBind :: EvBindsVar -> CoercionHole -> CoercionPlusHoles -> TcM () +addTcEvCoBind ebv hole co_plus_holes@(CPH { cph_co = co }) + = do { fillCoercionHole hole co_plus_holes + -- Record usage of the free vars of this coercion + ; let fvs = coVarsOfCo co + ; case ebv of + EvBindsVar { ebv_binds = bs_ref } + -> updTcRef bs_ref (addCoVarsEBS fvs) + CoEvBindsVar { ebv_needs = need_ref } + -> updTcRef need_ref (unionVarSet fvs) } + addTcEvBind :: EvBindsVar -> EvBind -> TcM () -- Add a binding to the TcEvBinds by side effect -addTcEvBind (EvBindsVar { ebv_binds = ev_ref, ebv_uniq = u }) ev_bind - = do { bnds <- readTcRef ev_ref - ; let bnds' = extendEvBinds bnds ev_bind +addTcEvBind (EvBindsVar { ebv_binds = ev_ref, ebv_uniq = u }) + ev_bind@(EvBind { eb_info = info, eb_rhs = rhs }) + = do { EBS { ebs_binds = bnds, ebs_needs = needs } <- readTcRef ev_ref + ; let bnds' = extendEvBinds bnds ev_bind + needs' = case info of + EvBindWanted {} -> nestedEvIdsOfTerm rhs + `unionVarSet` needs + EvBindGiven {} -> needs + ; traceTc "addTcEvBind" $ vcat [ text "EvBindsVar:" <+> ppr u , text "ev_bind:" <+> ppr ev_bind , text "bnds:" <+> ppr bnds - , text "bnds':" <+> ppr bnds' ] - ; writeTcRef ev_ref bnds' } + , text "bnds':" <+> ppr bnds' + , text "needs" <+> ppr needs + , text "needs'" <+> ppr needs' ] + + ; writeTcRef ev_ref $ + EBS { ebs_binds = bnds', ebs_needs = needs' } } + addTcEvBind (CoEvBindsVar { ebv_uniq = u }) ev_bind = pprPanic "addTcEvBind CoEvBindsVar" (ppr ev_bind $$ ppr u) -addTcEvBinds :: EvBindsVar -> EvBindMap -> TcM () --- ^ Add a collection of binding to the TcEvBinds by side effect -addTcEvBinds _ new_ev_binds - | isEmptyEvBindMap new_ev_binds - = return () -addTcEvBinds (EvBindsVar { ebv_binds = ev_ref, ebv_uniq = u }) new_ev_binds - = do { traceTc "addTcEvBinds" $ ppr u $$ - ppr new_ev_binds - ; old_bnds <- readTcRef ev_ref - ; writeTcRef ev_ref (old_bnds `unionEvBindMap` new_ev_binds) } -addTcEvBinds (CoEvBindsVar { ebv_uniq = u }) new_ev_binds - = pprPanic "addTcEvBinds CoEvBindsVar" (ppr new_ev_binds $$ ppr u) - chooseUniqueOccTc :: (OccSet -> OccName) -> TcM OccName chooseUniqueOccTc fn = do { env <- getGblEnv @@ -2137,111 +2244,22 @@ emitNamedTypeHole (name, tv) where occ = nameOccName name -{- Note [Constraints and errors] -~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ -Consider this (#12124): - - foo :: Maybe Int - foo = return (case Left 3 of - Left -> 1 -- Hard error here! - _ -> 0) - -The call to 'return' will generate a (Monad m) wanted constraint; but -then there'll be "hard error" (i.e. an exception in the TcM monad), from -the unsaturated Left constructor pattern. - -We'll recover in tcPolyBinds, using recoverM. But then the final -tcSimplifyTop will see that (Monad m) constraint, with 'm' utterly -un-filled-in, and will emit a misleading error message. - -The underlying problem is that an exception interrupts the constraint -gathering process. Bottom line: if we have an exception, it's best -simply to discard any gathered constraints. Hence in 'attemptM' we -capture the constraints in a fresh variable, and only emit them into -the surrounding context if we exit normally. If an exception is -raised, simply discard the collected constraints... we have a hard -error to report. So this capture-the-emit dance isn't as stupid as it -looks :-). - -However suppose we throw an exception inside an invocation of -captureConstraints, and discard all the constraints. Some of those -constraints might be "variable out of scope" Hole constraints, and that -might have been the actual original cause of the exception! For -example (#12529): - f = p @ Int -Here 'p' is out of scope, so we get an insoluble Hole constraint. But -the visible type application fails in the monad (throws an exception). -We must not discard the out-of-scope error. - -It's distressingly delicate though: - -* If we discard too /many/ constraints we may fail to report the error - that led us to interrupt the constraint gathering process. - - One particular example "variable out of scope" Hole constraints. For - example (#12529): - f = p @ Int - Here 'p' is out of scope, so we get an insoluble Hole constraint. But - the visible type application fails in the monad (throws an exception). - We must not discard the out-of-scope error. - - Also GHC.Tc.Solver.simplifyAndEmitFlatConstraints may fail having - emitted some constraints with skolem-escape problems. - -* If we discard too /few/ constraints, we may get the misleading - class constraints mentioned above. - - We may /also/ end up taking constraints built at some inner level, and - emitting them (via the exception catching in `tryCaptureConstraints` at some - outer level, and then breaking the TcLevel invariants See Note [TcLevel - invariants] in GHC.Tc.Utils.TcType - -So `dropMisleading` has a horridly ad-hoc structure: - -* It keeps only /insoluble/ flat constraints (which are unlikely to very visibly - trip up on the TcLevel invariant - -* But it keeps all /implication/ constraints (except the class constraints - inside them). The implication constraints are OK because they set the ambient - level before attempting to solve any inner constraints. - -Ugh! I hate this. But it seems to work. - -Other wrinkles - -(CERR1) Note that freshly-generated constraints like (Int ~ Bool), or - ((a -> b) ~ Int) are all CNonCanonical, and hence won't be flagged as - insoluble. The constraint solver does that. So they'll be discarded. - That's probably ok; but see th/5358 as a not-so-good example: - t1 :: Int - t1 x = x -- Manifestly wrong - - foo = $(...raises exception...) - We report the exception, but not the bug in t1. Oh well. Possible - solution: make GHC.Tc.Utils.Unify.uType spot manifestly-insoluble constraints. - -(CERR2) In #26015 I found that from the constraints - [W] alpha ~ Int -- A class constraint - [W] F alpha ~# Bool -- An equality constraint - we were dropping the first (becuase it's a class constraint) but not the - second, and then getting a misleading error message from the second. As - #25607 shows, we can get not just one but a zillion bogus messages, which - conceal the one genuine error. Boo. +-- | Put a value in a coercion hole +fillCoercionHole :: CoercionHole -> CoercionPlusHoles -> TcM () +fillCoercionHole (CH { ch_ref = ref, ch_co_var = cv }) co + = do { when debugIsOn $ + do { cts <- readTcRef ref + ; whenIsJust cts $ \old_co -> + pprPanic "Filling a filled coercion hole" (ppr cv $$ ppr co $$ ppr old_co) } + ; traceTc "Filling coercion hole" (ppr cv <+> text ":=" <+> ppr co) + ; writeTcRef ref (Just co) } - For now I have added an even more ad-hoc "drop class constraints except - equality classes (~) and (~~)"; see `dropMisleading`. That just kicks the can - down the road; but this problem seems somewhat rare anyway. The code in - `dropMisleading` hasn't changed for years. - -It would be great to have a more systematic solution to this entire mess. - -************************************************************************ +{- ********************************************************************* * * Template Haskell context * * -************************************************************************ --} +********************************************************************* -} recordThUse :: TcM () recordThUse = do { env <- getGblEnv; writeTcRef (tcg_th_used env) True } ===================================== compiler/GHC/Tc/Utils/TcMType.hs ===================================== @@ -341,31 +341,13 @@ newImplication (implicationPrototype (mkCtLocEnv env)) { ic_warn_inaccessible = warn_inaccessible && not in_gen_code } -{- -************************************************************************ -* * - Coercion holes -* * -************************************************************************ --} - newCoercionHole :: TcPredType -> TcM CoercionHole -- For the Bool, see (EIK2) in Note [Equalities with heterogeneous kinds] newCoercionHole pred_ty = do { co_var <- newEvVar pred_ty ; traceTc "New coercion hole:" (ppr co_var <+> dcolon <+> ppr pred_ty) ; ref <- newMutVar Nothing - ; return $ CoercionHole { ch_co_var = co_var, ch_ref = ref } } - --- | Put a value in a coercion hole -fillCoercionHole :: CoercionHole -> CoercionPlusHoles -> TcM () -fillCoercionHole (CoercionHole { ch_ref = ref, ch_co_var = cv }) co - = do { when debugIsOn $ - do { cts <- readTcRef ref - ; whenIsJust cts $ \old_co -> - pprPanic "Filling a filled coercion hole" (ppr cv $$ ppr co $$ ppr old_co) } - ; traceTc "Filling coercion hole" (ppr cv <+> text ":=" <+> ppr co) - ; writeTcRef ref (Just co) } + ; return $ CH { ch_co_var = co_var, ch_ref = ref } } {- ********************************************************************** * ===================================== compiler/GHC/Tc/Utils/Unify.hs ===================================== @@ -418,7 +418,8 @@ Some examples: -} tcSkolemiseGeneral - :: DeepSubsumptionFlag + :: HasDebugCallStack + => DeepSubsumptionFlag -> UserTypeCtxt -> TcType -> TcType -- top_ty and expected_ty -- Here, top_ty is the type we started to skolemise; used only in SigSkol @@ -446,15 +447,16 @@ tcSkolemiseGeneral ds_flag ctxt top_ty expected_ty thing_inside ; skol_info <- mkSkolemInfo sig_skol } ; let skol_tvs = map (binderVar . snd) tv_prs - ; traceTc "tcSkolemiseGeneral" (pprUserTypeCtxt ctxt <+> ppr skol_tvs <+> ppr given) + ; traceTc "tcSkolemiseGeneral {" (pprUserTypeCtxt ctxt <+> ppr skol_tvs <+> ppr given) ; (ev_binds, result) <- checkConstraints sig_skol skol_tvs given $ thing_inside tv_prs rho_ty + ; traceTc "tcSkolemiseGeneral }" (ppr ev_binds $$ traceCallStackDoc) ; return (wrap <.> mkWpLet ev_binds, result) } -- The ev_binds returned by checkConstraints is very -- often empty, in which case mkWpLet is a no-op -tcSkolemiseCompleteSig :: TcCompleteSig +tcSkolemiseCompleteSig :: HasDebugCallStack => TcCompleteSig -> ([ExpPatType] -> TcRhoType -> TcM result) -> TcM (HsWrapper, result) -- ^ The wrapper has type: spec_ty ~~> expected_ty @@ -471,7 +473,7 @@ tcSkolemiseCompleteSig (CSig { sig_bndr = poly_id, sig_ctxt = ctxt, sig_loc = lo tcExtendNameTyVarEnv (map (fmap binderVar) tv_prs) $ thing_inside (map (mkInvisExpPatType . snd) tv_prs) rho_ty } -tcSkolemiseExpectedType :: TcSigmaType +tcSkolemiseExpectedType :: HasDebugCallStack => TcSigmaType -> ([ExpPatType] -> TcRhoType -> TcM result) -> TcM (HsWrapper, result) -- Just like tcSkolemiseCompleteSig, except that we don't have a user-written @@ -483,14 +485,15 @@ tcSkolemiseExpectedType exp_ty thing_inside = tcSkolemiseGeneral Shallow GenSigCtxt exp_ty exp_ty $ \tv_prs rho_ty -> thing_inside (map (mkInvisExpPatType . snd) tv_prs) rho_ty -tcSkolemise :: DeepSubsumptionFlag -> UserTypeCtxt -> TcSigmaType +tcSkolemise :: HasDebugCallStack => DeepSubsumptionFlag -> UserTypeCtxt -> TcSigmaType -> (TcRhoType -> TcM result) -> TcM (HsWrapper, result) tcSkolemise ds_flag ctxt expected_ty thing_inside = tcSkolemiseGeneral ds_flag ctxt expected_ty expected_ty $ \_ rho_ty -> thing_inside rho_ty -checkConstraints :: SkolemInfoAnon +checkConstraints :: HasDebugCallStack + => SkolemInfoAnon -> [TcTyVar] -- Skolems -> [EvVar] -- Given -> TcM result @@ -504,14 +507,16 @@ checkConstraints skol_info skol_tvs given thing_inside ; if implication_needed then do { (tclvl, wanted, result) <- pushLevelAndCaptureConstraints thing_inside ; (implics, ev_binds) <- buildImplicationFor tclvl skol_info skol_tvs given wanted - ; traceTc "checkConstraints" (ppr tclvl $$ ppr skol_tvs) + ; traceTc "checkConstraints A" (ppr tclvl $$ ppr skol_tvs $$ traceCallStackDoc) ; emitImplications implics ; return (ev_binds, result) } else -- Fast path. We check every function argument with tcCheckPolyExpr, -- which uses tcTopSkolemise and hence checkConstraints. -- So this fast path is well-exercised - do { res <- thing_inside + do { traceTc "checkConstraints B" (ppr skol_tvs $$ ppr given $$ ppr skol_info $$ + traceCallStackDoc) + ; res <- thing_inside ; return (emptyTcEvBinds, res) } } checkTvConstraints :: SkolemInfo ===================================== compiler/GHC/Tc/Zonk/TcType.hs ===================================== @@ -236,7 +236,7 @@ zonkCo :: Coercion -> ZonkM Coercion , tcm_tycon = zonkTcTyCon } where hole :: () -> CoercionHole -> ZonkM Coercion - hole _ hole@(CoercionHole { ch_ref = ref, ch_co_var = cv }) + hole _ hole@(CH { ch_ref = ref, ch_co_var = cv }) = do { contents <- readTcRef ref ; case contents of Just (CPH { cph_co = co }) @@ -617,7 +617,7 @@ instance Monoid UnfilledCoercionHoleMonoid where -- | Is a coercion hole filled in? isFilledCoercionHole :: CoercionHole -> ZonkM Bool -isFilledCoercionHole (CoercionHole { ch_ref = ref }) +isFilledCoercionHole (CH { ch_ref = ref }) = isJust <$> readTcRef ref -- | Retrieve the contents of a coercion hole. Panics if the hole @@ -631,7 +631,7 @@ unpackCoercionHole hole -- | Retrieve the contents of a coercion hole, if it is filled unpackCoercionHole_maybe :: CoercionHole -> ZonkM (Maybe CoercionPlusHoles) -unpackCoercionHole_maybe (CoercionHole { ch_ref = ref }) = readTcRef ref +unpackCoercionHole_maybe (CH { ch_ref = ref }) = readTcRef ref {- ===================================== compiler/GHC/Tc/Zonk/Type.hs ===================================== @@ -485,7 +485,7 @@ zonkCoVarOcc cv _ -> mkCoVarCo <$> (lift $ liftZonkM $ zonkCoVar cv) } zonkCoHole :: CoercionHole -> ZonkTcM Coercion -zonkCoHole hole@(CoercionHole { ch_ref = ref, ch_co_var = cv }) +zonkCoHole hole@(CH { ch_ref = ref, ch_co_var = cv }) = do { contents <- readTcRef ref ; case contents of Just (CPH { cph_co = co }) @@ -1910,8 +1910,9 @@ zonk_tc_ev_binds (EvBinds bs) = zonkEvBinds bs zonkEvBindsVar :: EvBindsVar -> ZonkBndrTcM (Bag EvBind) zonkEvBindsVar (EvBindsVar { ebv_binds = ref }) - = do { bs <- readTcRef ref + = do { EBS { ebs_binds = bs } <- readTcRef ref ; zonkEvBinds (evBindMapBinds bs) } + zonkEvBindsVar (CoEvBindsVar {}) = return emptyBag zonkEvBinds :: Bag EvBind -> ZonkBndrTcM (Bag EvBind) ===================================== compiler/GHC/Utils/Trace.hs ===================================== @@ -11,6 +11,7 @@ module GHC.Utils.Trace , warnPprTraceM , pprTraceUserWarning , trace + , traceCallStackDoc ) where View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/22f6f55efff888690adc4d2b8ef394c… -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/22f6f55efff888690adc4d2b8ef394c… You're receiving this email because of your account on gitlab.haskell.org.

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[Git][ghc/ghc][wip/andreask/ticked_joins] Use the same logic for casts, see Note [Quasi join points]
by sheaf (＠sheaf) 22 Jan '26

22 Jan '26

sheaf pushed to branch wip/andreask/ticked_joins at Glasgow Haskell Compiler / GHC Commits: 443c2b50 by sheaf at 2026-01-22T17:49:54+01:00 Use the same logic for casts, see Note [Quasi join points] - - - - - 6 changed files: - compiler/GHC/Core/Lint.hs - compiler/GHC/Core/Opt/OccurAnal.hs - compiler/GHC/Core/Opt/Simplify/Env.hs - compiler/GHC/Core/Opt/Simplify/Iteration.hs - compiler/GHC/Core/SimpleOpt.hs - compiler/GHC/Types/Basic.hs Changes: ===================================== compiler/GHC/Core/Lint.hs ===================================== @@ -672,7 +672,7 @@ lintRhs :: Id -> CoreExpr -> LintM (OutType, UsageEnv) lintRhs bndr rhs | JoinPoint arity <- idJoinPointHood bndr = lintJoinLams arity (Just bndr) rhs - | AlwaysTailCalled arity _ <- tailCallInfo (idOccInfo bndr) + | AlwaysTailCalled { tailCallArity = arity } <- tailCallInfo (idOccInfo bndr) = lintJoinLams arity Nothing rhs -- Allow applications of the data constructor @StaticPtr@ at the top ===================================== compiler/GHC/Core/Opt/OccurAnal.hs ===================================== @@ -797,10 +797,10 @@ function call and a jump by looking at the occurrence (because the same pass changes the 'IdDetails' and propagates the binders to their occurrence sites). To track potential join points, we use the 'occ_tail' field of OccInfo. A value -of `AlwaysTailCalled n` indicates that every occurrence of the variable is a -tail call with `n` arguments (counting both value and type arguments). Otherwise -'occ_tail' will be 'NoTailCallInfo'. The tail call info flows bottom-up with the -rest of 'OccInfo' until it goes on the binder. +of `AlwaysTailCalled { tailCallArity = n }` indicates that every occurrence of +the variable is a tail call with `n` arguments (counting both value and type +arguments). Otherwise 'occ_tail' will be 'NoTailCallInfo'. The tail call info +flows bottom-up with the rest of 'OccInfo' until it goes on the binder. Note [Join arity prediction based on joinRhsArity] ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ @@ -2588,9 +2588,9 @@ occAnal env (Tick tickish body) WUD usage body' = occAnal env' body env' = case tickish of - -- Set that we are inside a profiling tick - -- SLD TODO: explain why we need this info - ProfNote {} -> setInProfTick env + -- setInsideProfTick: join points under profiling ticks turn + -- into quasi-join points. See Note [Quasi join points] + ProfNote {} -> setInsideProfTick env _ -> env usage' @@ -2621,11 +2621,12 @@ occAnal env (Tick tickish body) -- See #14242. occAnal env (Cast expr co) - = let (WUD usage expr') = occAnal env expr - usage1 = addManyOccs usage (coVarsOfCo co) - -- usage2: see Note [Gather occurrences of coercion variables] - usage2 = markAllNonTail usage1 - -- usage3: calls inside expr aren't tail calls any more + = let (WUD usage expr') = occAnal (setInsideCast env) expr + -- setInsideCasts: join points inside casts turn into quasi-join-points + -- See Note [Quasi join points] + usage1 = addManyOccs usage (coVarsOfCo co) + -- usage2: see Note [Gather occurrences of coercion variables] + usage2 = markAllNonTail usage1 in WUD usage2 (Cast expr' co) occAnal env app@(App _ _) @@ -2942,7 +2943,8 @@ scrutinised y). data OccEnv = OccEnv { occ_encl :: !OccEncl -- Enclosing context information - , occ_prof_ticks :: !Int + , occ_prof_ticks :: !Int -- ^ How many profiling ticks are we under? See Note [Quasi join points] + , occ_casts :: !Int -- ^ How many casts are we under? See Note [Quasi join points] , occ_one_shots :: !OneShots -- See Note [OneShots] , occ_unf_act :: Id -> Bool -- Which Id unfoldings are active , occ_rule_act :: ActivationGhc -> Bool -- Which rules are active @@ -3009,6 +3011,7 @@ initOccEnv :: OccEnv initOccEnv = OccEnv { occ_encl = OccVanilla , occ_prof_ticks = 0 + , occ_casts = 0 , occ_one_shots = [] -- To be conservative, we say that all @@ -3087,8 +3090,11 @@ setTailCtxt !env = env { occ_encl = OccVanilla } -- Preserve occ_one_shots, occ_join points -- Do not use OccRhs for the RHS of a join point (which is a tail ctxt): -setInProfTick :: OccEnv -> OccEnv -setInProfTick !env = env { occ_prof_ticks = 1 + occ_prof_ticks env } +setInsideProfTick :: OccEnv -> OccEnv +setInsideProfTick !env = env { occ_prof_ticks = 1 + occ_prof_ticks env } + +setInsideCast :: OccEnv -> OccEnv +setInsideCast !env = env { occ_casts = 1 + occ_casts env } mkRhsOccEnv :: OccEnv -> RecFlag -> OccEncl -> JoinPointHood -> Id -> CoreExpr -> OccEnv -- See Note [The OccEnv for a right hand side] @@ -3736,7 +3742,7 @@ type OccInfoEnv = IdEnv LocalOcc -- A finite map from an expression's data LocalOcc -- See Note [LocalOcc] = OneOccL { lo_n_br :: {-# UNPACK #-} !BranchCount -- Number of syntactic occurrences , lo_tail :: !TailCallInfo - -- Combining (AlwaysTailCalled 2) and (AlwaysTailCalled 3) + -- NB: combining 'TailCallInfo's with different arities -- gives NoTailCallInfo , lo_int_cxt :: !InterestingCxt } @@ -3829,9 +3835,20 @@ mkOneOcc !env id int_cxt arity = mkSimpleDetails (unitVarEnv id occ) where - occ = OneOccL { lo_n_br = 1 - , lo_int_cxt = int_cxt - , lo_tail = AlwaysTailCalled arity (occ_prof_ticks env) } + occ = + OneOccL + { lo_n_br = 1 + , lo_int_cxt = int_cxt + , lo_tail = + AlwaysTailCalled + { tailCallArity = arity + + -- See Note [Quasi join points] for justification of these + -- two fields. + , tailCallUnderProfTicks = occ_prof_ticks env + , tailCallUnderCasts = occ_casts env + } + } -- Add several occurrences, assumed not to be tail calls add_many_occ :: Var -> OccInfoEnv -> OccInfoEnv @@ -4040,7 +4057,7 @@ tagNonRecBinder :: TopLevelFlag -- At top level? -- Precondition: OccInfo is not IAmDead tagNonRecBinder lvl occ bndr | okForJoinPoint lvl bndr tail_call_info - , AlwaysTailCalled ar _ <- tail_call_info + , AlwaysTailCalled { tailCallArity = ar } <- tail_call_info = (setBinderOcc occ bndr, JoinPoint ar) | otherwise = (setBinderOcc zapped_occ bndr, NotJoinPoint) @@ -4127,7 +4144,7 @@ okForJoinPoint lvl bndr tail_call_info = False where valid_join | NotTopLevel <- lvl - , AlwaysTailCalled arity _ <- tail_call_info + , AlwaysTailCalled { tailCallArity = arity } <- tail_call_info , -- Invariant 1 as applied to LHSes of rules all (ok_rule arity) (idCoreRules bndr) @@ -4144,9 +4161,9 @@ okForJoinPoint lvl bndr tail_call_info lost_join | JoinPoint ja <- idJoinPointHood bndr = not valid_join || - (case tail_call_info of -- Valid join but arity differs - AlwaysTailCalled ja' _ -> ja /= ja' - _ -> False) + (case tail_call_info of -- Valid join but arity differs + AlwaysTailCalled { tailCallArity = ja' } -> ja /= ja' + _ -> False) | otherwise = False ok_rule _ BuiltinRule{} = False -- only possible with plugin shenanigans @@ -4168,7 +4185,7 @@ okForJoinPoint lvl bndr tail_call_info , text "tc:" <+> ppr tail_call_info , text "rules:" <+> ppr (idCoreRules bndr) , case tail_call_info of - AlwaysTailCalled arity _ -> + AlwaysTailCalled { tailCallArity = arity } -> vcat [ text "ok_unf:" <+> ppr (ok_unfolding arity (realIdUnfolding bndr)) , text "ok_type:" <+> ppr (isValidJoinPointType arity (idType bndr)) ] _ -> empty ] @@ -4231,6 +4248,6 @@ orLocalOcc (OneOccL { lo_n_br = nbr1, lo_int_cxt = int_cxt1, lo_tail = tci1 }) orLocalOcc occ1 occ2 = andLocalOcc occ1 occ2 andTailCallInfo :: TailCallInfo -> TailCallInfo -> TailCallInfo -andTailCallInfo (AlwaysTailCalled arity1 p1) (AlwaysTailCalled arity2 p2) - | arity1 == arity2 = AlwaysTailCalled arity1 (max p1 p2) +andTailCallInfo (AlwaysTailCalled arity1 p1 c1) (AlwaysTailCalled arity2 p2 c2) + | arity1 == arity2 = AlwaysTailCalled arity1 (max p1 p2) (max c1 c2) andTailCallInfo _ _ = NoTailCallInfo ===================================== compiler/GHC/Core/Opt/Simplify/Env.hs ===================================== @@ -201,7 +201,8 @@ data SimplEnv , seCaseDepth :: !Int -- Depth of multi-branch case alternatives - , seProfTicks :: !Int -- SLD TODO + , seProfTicks :: !Int -- Current depth of profiling ticks; see Note [Quasi join points] + , seCasts :: !Int -- Current depth of casts; see Note [Quasi join points] , seInlineDepth :: !Int -- 0 initially, 1 when we inline an already-simplified -- unfolding, and simplify again; and so on @@ -591,6 +592,7 @@ mkSimplEnv mode fam_envs , seRecIds = emptyUnVarSet , seCaseDepth = 0 , seProfTicks = 0 + , seCasts = 0 , seInlineDepth = 0 } -- The top level "enclosing CC" is "SUBSUMED". ===================================== compiler/GHC/Core/Opt/Simplify/Iteration.hs ===================================== @@ -61,7 +61,7 @@ import GHC.Types.Var ( isTyCoVar ) import GHC.Builtin.Types.Prim( realWorldStatePrimTy ) import GHC.Builtin.Names( runRWKey, seqHashKey ) -import GHC.Data.Maybe ( isNothing, orElse, fromMaybe, mapMaybe ) +import GHC.Data.Maybe ( isNothing, orElse, mapMaybe ) import GHC.Data.FastString import GHC.Unit.Module ( moduleName ) import GHC.Utils.Outputable @@ -1684,39 +1684,54 @@ optOutCoercion env co already_optimised empty_subst = mkEmptySubst (seInScope env) opts = seOptCoercionOpts env +-- | Number of casts we are adding around an expression as we process a 'Cast'. +-- +-- We need the cast depth to implement the logic of Note [Quasi join points]. +type NbCastsAdded = Int + simplCast :: SimplEnv -> InExpr -> InCoercion -> SimplCont -> SimplM (SimplFloats, OutExpr) simplCast env body co0 cont0 = do { co1 <- {-#SCC "simplCast-simplCoercion" #-} simplCoercion env co0 - ; cont1 <- {-#SCC "simplCast-addCoerce" #-} - if isReflCo co1 - then return cont0 -- See Note [Optimising reflexivity] - else addCoerce co1 True cont0 - -- True <=> co1 is optimised - ; {-#SCC "simplCast-simplExprF" #-} simplExprF env body cont1 } + ; (cont1, nbAddedCasts) <- {-#SCC "simplCast-addCoerce" #-} + if isReflCo co1 + then return (cont0, 0) -- See Note [Optimising reflexivity] + else addCoerce co1 True cont0 + -- True <=> co1 is optimised + + -- Keep track of how many casts we have added, because we need this + -- information for Note [Quasi join points]. + ; let env' = env { seCasts = seCasts env + nbAddedCasts } + ; {-#SCC "simplCast-simplExprF" #-} simplExprF env' body cont1 } where -- If the first parameter is MRefl, then simplifying revealed a -- reflexive coercion. Omit. - addCoerceM :: MOutCoercion -> Bool -> SimplCont -> SimplM SimplCont - addCoerceM MRefl _ cont = return cont + addCoerceM :: MOutCoercion -> Bool -> SimplCont -> SimplM (SimplCont, NbCastsAdded) + addCoerceM MRefl _ cont = return (cont, 0) addCoerceM (MCo co) opt cont = addCoerce co opt cont - addCoerce :: OutCoercion -> Bool -> SimplCont -> SimplM SimplCont + addCoerce :: OutCoercion -> Bool -> SimplCont -> SimplM (SimplCont, NbCastsAdded) addCoerce co1 _ (CastIt { sc_co = co2, sc_cont = cont }) -- See Note [Optimising reflexivity] - = addCoerce (mkTransCo co1 co2) False cont - -- False: (mkTransCo co1 co2) is not fully optimised - -- See Note [Avoid re-simplifying coercions] + = do { (cont', nbCastsAdded) <- addCoerce (mkTransCo co1 co2) False cont + -- False: (mkTransCo co1 co2) is not fully optimised + -- See Note [Avoid re-simplifying coercions] + ; return (cont', nbCastsAdded - 1) + -- -1: the coercion coalesced with an existing coercion. + } addCoerce co co_is_opt (ApplyToTy { sc_arg_ty = arg_ty, sc_cont = tail }) | Just (arg_ty', m_co') <- pushCoTyArg co arg_ty = {-#SCC "addCoerce-pushCoTyArg" #-} - do { tail' <- addCoerceM m_co' co_is_opt tail - ; return (ApplyToTy { sc_arg_ty = arg_ty' - , sc_cont = tail' - , sc_hole_ty = coercionLKind co }) } - -- NB! As the cast goes past, the - -- type of the hole changes (#16312) + do { (tail', nbCastsAdded) <- addCoerceM m_co' co_is_opt tail + ; return ( ApplyToTy { sc_arg_ty = arg_ty' + , sc_cont = tail' + , sc_hole_ty = coercionLKind co } + -- NB! As the cast goes past, the + -- type of the hole changes (#16312) + , nbCastsAdded ) + } + -- (f |> co) e ===> (f (e |> co1)) |> co2 -- where co :: (s1->s2) ~ (t1->t2) -- co1 :: t1 ~ s1 @@ -1729,10 +1744,12 @@ simplCast env body co0 cont0 | Just (m_co1, m_co2) <- pushCoValArg co = {-#SCC "addCoerce-pushCoValArg" #-} - do { tail' <- addCoerceM m_co2 co_is_opt tail + do { (tail', nbCastsAdded) <- addCoerceM m_co2 co_is_opt tail ; case m_co1 of { - MRefl -> return (cont { sc_cont = tail' - , sc_hole_ty = coercionLKind co }) ; + MRefl -> return + ( cont { sc_cont = tail' + , sc_hole_ty = coercionLKind co } + , nbCastsAdded ) ; -- See Note [Avoiding simplifying repeatedly] MCo co1 -> @@ -1742,17 +1759,23 @@ simplCast env body co0 cont0 -- to make it all consistent. It's a bit messy. -- But it isn't a common case. -- Example of use: #995 - ; return (ApplyToVal { sc_arg = mkCast arg' co1 - , sc_env = arg_se' - , sc_dup = dup' - , sc_cont = tail' - , sc_hole_ty = coercionLKind co }) } } } + ; return + ( ApplyToVal { sc_arg = mkCast arg' co1 + , sc_env = arg_se' + , sc_dup = dup' + , sc_cont = tail' + , sc_hole_ty = coercionLKind co } + , nbCastsAdded ) } } } addCoerce co co_is_opt cont - | isReflCo co = return cont -- Having this at the end makes a huge - -- difference in T12227, for some reason - -- See Note [Optimising reflexivity] - | otherwise = return (CastIt { sc_co = co, sc_opt = co_is_opt, sc_cont = cont }) + | isReflCo co = return (cont, 0 :: NbCastsAdded ) + -- Having this at the end makes a huge + -- difference in T12227, for some reason + -- See Note [Optimising reflexivity] + | otherwise = + return + ( CastIt { sc_co = co, sc_opt = co_is_opt, sc_cont = cont } + , 1 :: NbCastsAdded ) simplLazyArg :: SimplEnvIS -- ^ Used only for its InScopeSet -> DupFlag @@ -2067,12 +2090,10 @@ simplNonRecJoinPoint env bndr rhs body cont ; (floats2, body') <- simplExprF env3 body cont ; return (floats1 `addFloats` floats2, body') } where - do_case_case - | Just occMaxProfTicks <- occursUnderProfTick (idOccInfo bndr) - , occMaxProfTicks > seProfTicks env - = False - | otherwise - = seCaseCase env + do_case_case = + if isTrueJoinPoint env bndr + then seCaseCase env + else False simplRecJoinPoint :: SimplEnv -> [(InId, InExpr)] -> InExpr -> SimplCont @@ -2089,11 +2110,26 @@ simplRecJoinPoint env pairs body cont ; (floats2, body') <- simplExprF env2 body cont ; return (floats1 `addFloats` floats2, body') } where - do_case_case - | any ((seProfTicks env <) . fromMaybe 0 . occursUnderProfTick . idOccInfo . fst) pairs - = False - | otherwise - = seCaseCase env + do_case_case = + if all (isTrueJoinPoint env . fst) pairs + then seCaseCase env + else False + +-- | Is this a true join point, or only a quasi join point? +-- +-- See Note [Quasi join points] +isTrueJoinPoint :: SimplEnv -> InId -> Bool +isTrueJoinPoint env id + | Just occMaxProfTicks <- occursUnderProfTicks (idOccInfo id) + , occMaxProfTicks > seProfTicks env + -- The join point occurs under more profiling ticks that its binding. + = False + | Just occMaxCasts <- occursUnderCasts (idOccInfo id) + , occMaxCasts > seCasts env + -- The join point occurs under more casts than its binding. + = False + | otherwise + = True -------------------- wrapJoinCont :: Bool @@ -2217,6 +2253,100 @@ inwards altogether at any join point. Instead simplify the (join ... in ...) with a Stop continuation, and wrap the original continuation around the outside. Surprisingly tricky! +Note [Quasi join points] +~~~~~~~~~~~~~~~~~~~~~~~~ +We currently classify join points into two separate categories + + - true join points + - quasi join points + +Definition: + A join point binding defines a *quasi* join point if any of the join point + binders occur under profiling ticks or casts. + + If a join point binding is not a quasi join point, it is a *true* join point. + +For true join points, we can push a continuation into a join point, as described +in Note [Join points and case-of-case]: + + K[ join j = rhs in body ] --> join j = K[ rhs ] in K[ body ] + +This transformation is not valid if the occurrences of 'j' in 'body' appear: + + 1. under casts, see #26422 + 2. under profiling ticks, see #26693 #26157 #26642 + +For example, consider (a minimisation of) the program in #26693: + + join { j :: Bool -> IO (); j _ = guts } + in case pass of + False -> scctick<foo> jump j True + True -> scctick<bar> jump j False + +Let's try to push an application to an argument 'arg' into this expression. +As per Note [Join points and case-of-case], we proceed by first applying the +argument to both the join point RHS and the case alternatives: + + join { j :: Bool -> IO (); j _ = guts arg ] } + in case pass of + False -> (scctick<foo> jump j True ) arg + True -> (scctick<bar> jump j False) arg + +Then we rely on 'trimJoinCont' to remove the argument, but this fails because +there are intervening profiling ticks. Even if we addressed that issue, it +remains unclear what to do without misattributing costs. +We could transform to the following: + + join { j :: Bool -> IO (); j scc _ = (setSCC# scc guts) arg ] } + in case pass of + False -> jump j <foo> True + True -> jump j <bar> False + +where `setSCC#` is a new primop that would set the current cost centre point. +This doesn't exist yet, so for now we just disallow the case-of-case +transformation for 'j'. + +Similarly for casts: + + join { j = blah } + in case e of + False -> j True |> co1 + True -> j False |> co2 + +if we want to apply this to an argument 'arg', we would need to perform the +following transformation: + + join { j co = ( blah |> co ) arg } + in case e of + False -> j co1 True + True -> j co2 False + +in which we add a coercion argument to the join point. Again, this is not a +transformation we currently implement, so we instead prevent case-of-case for +such join points. + +To achieve this classification, we proceed as follows: + + 1. In occurrence analysis, compute how many profiling ticks/casts each + join point Id occurs under. + + This is stored in the 'tailCallUnderProfTicks' and 'tailCallUnderCasts' + fields of 'TailCallInfo', and populated by keeping track of how many + profiling ticks and casts we are under when doing occurrence analysis + (see 'occ_prof_ticks' and 'occ_casts'). + + 2. In the simplifier, we keep track of how many profiling ticks/casts we are + currently inside. See 'seProfTicks' and 'seCasts', which are updated + in 'simplTick' and 'simplCast', respectively. + + 3. In the simplifier, when we come across a join point (in either + 'simplNonRecJoinPoint' or 'simplRecJoinPoint'), we compare the current + cast depth/profiling tick depth with the cast depth/profiling tick depth + of the occurrences. + + If the join point occurs under more profiling ticks/casts than it is bound, + then it is a quasi join point and we switch off the case-of-case + transformation. ************************************************************************ * * ===================================== compiler/GHC/Core/SimpleOpt.hs ===================================== @@ -1076,7 +1076,7 @@ joinPointBinding_maybe bndr rhs | isJoinId bndr = Just (bndr, rhs) - | AlwaysTailCalled join_arity _ <- tailCallInfo (idOccInfo bndr) + | AlwaysTailCalled { tailCallArity = join_arity } <- tailCallInfo (idOccInfo bndr) , (bndrs, body) <- etaExpandToJoinPoint join_arity rhs , let str_sig = idDmdSig bndr str_arity = count isId bndrs -- Strictness demands are for Ids only ===================================== compiler/GHC/Types/Basic.hs ===================================== @@ -70,7 +70,7 @@ module GHC.Types.Basic ( BranchCount, oneBranch, InterestingCxt(..), TailCallInfo(..), tailCallInfo, zapOccTailCallInfo, - isAlwaysTailCalled, occursUnderProfTick, + isAlwaysTailCalled, occursUnderProfTicks, occursUnderCasts, EP(..), @@ -1149,8 +1149,14 @@ instance Monoid InsideLam where mappend = (Semi.<>) ----------------- + +-- | See Note [TailCallInfo] data TailCallInfo - = AlwaysTailCalled {-# UNPACK #-} !JoinArity !Int-- See Note [TailCallInfo] + = AlwaysTailCalled + { tailCallArity :: {-# UNPACK #-} !JoinArity + , tailCallUnderProfTicks :: !Int -- See Note [Quasi join points] + , tailCallUnderCasts :: !Int -- See Note [Quasi join points] + } | NoTailCallInfo deriving (Eq) @@ -1167,15 +1173,26 @@ isAlwaysTailCalled occ = case tailCallInfo occ of AlwaysTailCalled{} -> True NoTailCallInfo -> False -occursUnderProfTick :: OccInfo -> Maybe Int -occursUnderProfTick occ = +-- | If this 'Id' is always tail called, how many profiling ticks does +-- it occur under? See Note [Quasi join points]. +occursUnderProfTicks :: OccInfo -> Maybe Int +occursUnderProfTicks occ = case tailCallInfo occ of - AlwaysTailCalled _ b -> Just b + AlwaysTailCalled { tailCallUnderProfTicks = nb } -> Just nb + NoTailCallInfo -> Nothing + +-- | If this 'Id' is always tail called, how many casts does +-- it occur under? See Note [Quasi join points]. +occursUnderCasts :: OccInfo -> Maybe Int +occursUnderCasts occ = + case tailCallInfo occ of + AlwaysTailCalled { tailCallUnderCasts = nb } -> Just nb NoTailCallInfo -> Nothing instance Outputable TailCallInfo where - ppr (AlwaysTailCalled ar b) = sep [ text "Tail", brackets (int b), int ar ] - ppr _ = text "NoTailCallInfo" --empty + ppr (AlwaysTailCalled ar p c) = + sep [ text "Tail", brackets (int p <> comma <> int c), int ar ] + ppr NoTailCallInfo = text "NoTailCallInfo" ----------------- strongLoopBreaker, weakLoopBreaker :: OccInfo @@ -1223,8 +1240,10 @@ instance Outputable OccInfo where pp_tail = pprShortTailCallInfo tail_info pprShortTailCallInfo :: TailCallInfo -> SDoc -pprShortTailCallInfo (AlwaysTailCalled ar p) - = char 'T' <> (brackets (text "P" <+> int p)) <> brackets (int ar) +pprShortTailCallInfo (AlwaysTailCalled ar p c) + = char 'T' <> (brackets (text "P" <+> int p)) + <> (brackets (text "C" <+> int c)) + <> brackets (int ar) pprShortTailCallInfo NoTailCallInfo = empty {- @@ -1258,6 +1277,9 @@ point can also be invoked from other join points, not just from case branches: Here both 'j1' and 'j2' will get marked AlwaysTailCalled, but j1 will get ManyOccs and j2 will get `OneOcc { occ_n_br = 2 }`. +We also store how many profiling ticks and casts the join point occurs under. +The rationale is described in Note [Quasi join points]. + ************************************************************************ * * Default method specification View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/443c2b505ef239e9d73f49777585520… -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/443c2b505ef239e9d73f49777585520… You're receiving this email because of your account on gitlab.haskell.org.

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[Git][ghc/ghc] Pushed new branch wip/llvm-22
by Cheng Shao (＠TerrorJack) 22 Jan '26

22 Jan '26

Cheng Shao pushed new branch wip/llvm-22 at Glasgow Haskell Compiler / GHC -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/tree/wip/llvm-22 You're receiving this email because of your account on gitlab.haskell.org.

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[Git][ghc/ghc][wip/marge_bot_batch_merge_job] 6 commits: doc: update Flavour type in hadrian user-settings
by Marge Bot (＠marge-bot) 22 Jan '26

22 Jan '26

Marge Bot pushed to branch wip/marge_bot_batch_merge_job at Glasgow Haskell Compiler / GHC Commits: 18bf7f5c by Léana Jiang at 2026-01-22T08:58:45-05:00 doc: update Flavour type in hadrian user-settings - - - - - 3d5a1365 by Cheng Shao at 2026-01-22T08:59:28-05:00 hadrian: add missing notCross predicate for stage0 -O0 There are a few hard-coded hadrian args that pass -O0 when compiling some heavy modules in stage0, which only makes sense when not cross-compiling and when cross-compiling we need properly optimized stage0 packages. So this patch adds the missing `notCross` predicate in those places. - - - - - ee937134 by Matthew Pickering at 2026-01-22T09:00:10-05:00 Fix ghc-experimental GHC.Exception.Backtrace.Experimental module This module wasn't added to the cabal file so it was never compiled or included in the library. - - - - - 1b490f5a by Zubin Duggal at 2026-01-22T09:00:53-05:00 hadrian: Add ghc-{experimental,internal}.cabal to the list of dependencies of the doc target We need these files to detect the version of these libraries Fixes #26738 - - - - - 7b6c84f5 by Cheng Shao at 2026-01-22T09:32:08-05:00 rts: avoid Cmm loop to initialize Array#/SmallArray# Previously, `newArray#`/`newSmallArray#` called an RTS C function to allocate the `Array#`/`SmallArray#`, then used a Cmm loop to initialize the elements. Cmm doesn't have native for-loop so the code is a bit awkward, and it's less efficient than a C loop, since the C compiler can effectively vectorize the loop with optimizations. So this patch moves the loop that initializes the elements to the C side. `allocateMutArrPtrs`/`allocateSmallMutArrPtrs` now takes a new `init` argument and initializes the elements if `init` is non-NULL. - - - - - 8f45dfca by Cheng Shao at 2026-01-22T09:32:09-05:00 Fix testsuite run for +ipe flavour transformer This patch makes the +ipe flavour transformer pass the entire testsuite: - An RTS debug option `-DI` is added, the IPE trace information is now only printed with `-DI`. The test cases that do require IPE trace are now run with `-DI`. - The testsuite config option `ghc_with_ipe` is added, enabled when running the testsuite with `+ipe`, which skips a few tests that are sensitive to eventlog output, allocation patterns etc that can fail under `+ipe`. This is the first step towards #26799. Co-authored-by: Codex <codex(a)openai.com> - - - - - 26 changed files: - docs/users_guide/runtime_control.rst - hadrian/doc/user-settings.md - hadrian/src/Flavour.hs - hadrian/src/Rules/Documentation.hs - hadrian/src/Settings/Packages.hs - libraries/ghc-compact/tests/all.T - libraries/ghc-experimental/ghc-experimental.cabal.in - libraries/ghc-experimental/src/GHC/Exception/Backtrace/Experimental.hs - libraries/ghc-internal/tests/backtraces/all.T - rts/AllocArray.c - rts/AllocArray.h - rts/ClosureTable.c - rts/Heap.c - rts/PrimOps.cmm - rts/RtsFlags.c - rts/Threads.c - rts/Trace.c - rts/Weak.c - rts/include/rts/Flags.h - testsuite/driver/testglobals.py - testsuite/driver/testlib.py - testsuite/tests/interface-stability/ghc-experimental-exports.stdout - testsuite/tests/interface-stability/ghc-experimental-exports.stdout-mingw32 - testsuite/tests/rts/Makefile - testsuite/tests/rts/all.T - testsuite/tests/rts/ipe/all.T Changes: ===================================== docs/users_guide/runtime_control.rst ===================================== @@ -1588,6 +1588,7 @@ recommended for everyday use! .. rts-flag:: -Ds DEBUG: scheduler .. rts-flag:: -Di DEBUG: interpreter +.. rts-flag:: -DI DEBUG: IPE .. rts-flag:: -Dw DEBUG: weak .. rts-flag:: -DG DEBUG: gccafs .. rts-flag:: -Dg DEBUG: gc ===================================== hadrian/doc/user-settings.md ===================================== @@ -19,14 +19,18 @@ A build _flavour_ is a collection of build settings that fully define a GHC buil data Flavour = Flavour { -- | Flavour name, to select this flavour from command line. name :: String, - -- | Use these command line arguments. - args :: Args, + -- | Use these extra command line arguments. + -- This can't depend on the result of configuring a package (ie, using readContextData) + extraArgs :: Args, -- | Build these packages. packages :: Stage -> Action [Package], -- | Bignum backend: 'native', 'gmp', 'ffi', etc. bignumBackend :: String, -- | Check selected bignum backend against native backend bignumCheck :: Bool, + -- | Build the @text@ package with @simdutf@ support. Disabled by + -- default due to packaging difficulties described in #20724. + textWithSIMDUTF :: Bool, -- | Build libraries these ways. libraryWays :: Ways, -- | Build RTS these ways. @@ -45,11 +49,18 @@ data Flavour = Flavour { -- | Build the GHC executable against the threaded runtime system. ghcThreaded :: Stage -- ^ stage of the /built/ compiler -> Bool, + + ghcSplitSections :: Bool, -- ^ Whether to enable split sections -- | Whether to build docs and which ones -- (haddocks, user manual, haddock manual) ghcDocs :: Action DocTargets, + + -- | Whether to uses hashes or inplace for unit ids + hashUnitIds :: Bool, + -- | Whether to generate .hie files ghcHieFiles :: Stage -> Bool + } ``` Hadrian provides several built-in flavours (`default`, `quick`, and a few ===================================== hadrian/src/Flavour.hs ===================================== @@ -384,9 +384,15 @@ omitPragmas = addArgs -- | Build stage2 dependencies with options to enable IPE debugging -- information. enableIPE :: Flavour -> Flavour -enableIPE = addArgs - $ notStage0 ? builder (Ghc CompileHs) - ? pure ["-finfo-table-map", "-fdistinct-constructor-tables"] +enableIPE = + addArgs $ + mconcat + [ notStage0 + ? builder (Ghc CompileHs) + ? pure + ["-finfo-table-map", "-fdistinct-constructor-tables"], + builder Testsuite ? arg "--config=ghc_with_ipe=True" + ] enableLateCCS :: Flavour -> Flavour enableLateCCS = addArgs ===================================== hadrian/src/Rules/Documentation.hs ===================================== @@ -74,6 +74,8 @@ needDocDeps = do let templatedCabalFiles = map pkgCabalFile [ ghcBoot , ghcBootTh + , ghcExperimental + , ghcInternal , ghci , compiler , ghcHeap ===================================== hadrian/src/Settings/Packages.hs ===================================== @@ -53,7 +53,7 @@ packageArgs = do -- for Stage0 only so we can link ghc-pkg against it, so there is little -- reason to spend the effort to optimise it. , package cabal ? - stage0 ? builder Ghc ? arg "-O0" + andM [stage0, notCross] ? builder Ghc ? arg "-O0" ------------------------------- compiler ------------------------------- , package compiler ? mconcat @@ -71,7 +71,7 @@ packageArgs = do -- These files take a very long time to compile with -O1, -- so we use -O0 for them just in Stage0 to speed up the -- build but not affect Stage1+ executables - , inputs ["**/GHC/Hs/Instances.hs", "**/GHC/Driver/Session.hs"] ? stage0 ? + , inputs ["**/GHC/Hs/Instances.hs", "**/GHC/Driver/Session.hs"] ? andM [stage0, notCross] ? pure ["-O0"] ] , builder (Cabal Setup) ? mconcat ===================================== libraries/ghc-compact/tests/all.T ===================================== @@ -20,7 +20,8 @@ test('compact_gc', [fragile_for(17253, ['ghci']), ignore_stdout], compile_and_ru # this test computes closure sizes and those are affected # by the ghci and prof ways, because of BCOs and profiling headers. # Optimization levels slightly change what is/isn't shared so only run in normal mode -test('compact_share', only_ways(['normal']), compile_and_run, ['']) +test('compact_share', [only_ways(['normal']), when(ghc_with_ipe(), skip)], # IPE changes allocation/layout affecting compactSize output. + compile_and_run, ['']) test('compact_bench', [ ignore_stdout, extra_run_opts('100') ], compile_and_run, ['']) test('T17044', normal, compile_and_run, ['']) ===================================== libraries/ghc-experimental/ghc-experimental.cabal.in ===================================== @@ -44,6 +44,7 @@ library GHC.Stats.Experimental Prelude.Experimental System.Mem.Experimental + GHC.Exception.Backtrace.Experimental if arch(wasm32) exposed-modules: GHC.Wasm.Prim other-extensions: ===================================== libraries/ghc-experimental/src/GHC/Exception/Backtrace/Experimental.hs ===================================== @@ -15,7 +15,7 @@ module GHC.Exception.Backtrace.Experimental , getBacktraceMechanismState , setBacktraceMechanismState -- * Collecting backtraces - , Backtraces(..), + , Backtraces(..) , displayBacktraces , collectBacktraces -- * Collecting exception annotations on throwing 'Exception's ===================================== libraries/ghc-internal/tests/backtraces/all.T ===================================== @@ -2,5 +2,5 @@ test('T14532a', [], compile_and_run, ['']) test('T14532b', [], compile_and_run, ['']) test('T26507', [ when(have_profiling(), extra_ways(['prof'])) , when(js_arch(), skip) - , exit_code(1)], compile_and_run, ['']) - + , when(ghc_with_ipe(), skip) # IPE builds include an IPE backtrace section on stderr. + , exit_code(1)], compile_and_run, ['']) ===================================== rts/AllocArray.c ===================================== @@ -5,6 +5,7 @@ StgMutArrPtrs *allocateMutArrPtrs (Capability *cap, StgWord nelements, + StgClosure *init, CostCentreStack *ccs USED_IF_PROFILING) { /* All sizes in words */ @@ -25,6 +26,12 @@ StgMutArrPtrs *allocateMutArrPtrs (Capability *cap, arr->ptrs = nelements; arr->size = arrsize; + if (init != NULL) { + for (StgWord i = 0; i < nelements; ++i) { + arr->payload[i] = init; + } + } + /* Initialize the card array. Note that memset needs sizes in bytes. */ memset(&(arr->payload[nelements]), 0, mutArrPtrsCards(nelements)); @@ -33,6 +40,7 @@ StgMutArrPtrs *allocateMutArrPtrs (Capability *cap, StgSmallMutArrPtrs *allocateSmallMutArrPtrs (Capability *cap, StgWord nelements, + StgClosure *init, CostCentreStack *ccs USED_IF_PROFILING) { @@ -47,6 +55,13 @@ StgSmallMutArrPtrs *allocateSmallMutArrPtrs (Capability *cap, /* No write barrier needed since this is a new allocation. */ SET_HDR(arr, &stg_SMALL_MUT_ARR_PTRS_DIRTY_info, ccs); arr->ptrs = nelements; + + if (init != NULL) { + for (StgWord i = 0; i < nelements; ++i) { + arr->payload[i] = init; + } + } + return arr; } ===================================== rts/AllocArray.h ===================================== @@ -21,16 +21,19 @@ */ /* Allocate a StgMutArrPtrs for a given number of elements. It is allocated in - * the DIRTY state. + * the DIRTY state. If init is non-NULL, initialize payload elements to init. */ StgMutArrPtrs *allocateMutArrPtrs (Capability *cap, StgWord nelements, + StgClosure *init, CostCentreStack *ccs); -/* Allocate a StgSmallMutArrPtrs for a given number of elements. +/* Allocate a StgSmallMutArrPtrs for a given number of elements. If init is + * non-NULL, initialize payload elements to init. */ StgSmallMutArrPtrs *allocateSmallMutArrPtrs (Capability *cap, StgWord nelements, + StgClosure *init, CostCentreStack *ccs); /* Allocate a StgArrBytes for a given number of bytes. ===================================== rts/ClosureTable.c ===================================== @@ -46,7 +46,7 @@ bool enlargeClosureTable(Capability *cap, ClosureTable *t, int newcapacity) ASSERT(newcapacity > oldcapacity); StgMutArrPtrs *newarr; - newarr = allocateMutArrPtrs(cap, newcapacity, CCS_SYSTEM_OR_NULL); + newarr = allocateMutArrPtrs(cap, newcapacity, NULL, CCS_SYSTEM_OR_NULL); if (RTS_UNLIKELY(newarr == NULL)) return false; StgArrBytes *newfree; @@ -276,4 +276,3 @@ static bool isCompactClosureTable(ClosureTable *t) } return isCompact; } - ===================================== rts/Heap.c ===================================== @@ -279,7 +279,7 @@ StgMutArrPtrs *heap_view_closurePtrs(Capability *cap, StgClosure *closure) { StgClosure **ptrs = (StgClosure **) stgMallocBytes(sizeof(StgClosure *) * size, "heap_view_closurePtrs"); StgWord nptrs = collect_pointers(closure, ptrs); - StgMutArrPtrs *arr = allocateMutArrPtrs(cap, nptrs, cap->r.rCCCS); + StgMutArrPtrs *arr = allocateMutArrPtrs(cap, nptrs, NULL, cap->r.rCCCS); if (RTS_UNLIKELY(arr == NULL)) goto end; SET_INFO((StgClosure *) arr, &stg_MUT_ARR_PTRS_FROZEN_CLEAN_info); ===================================== rts/PrimOps.cmm ===================================== @@ -386,24 +386,11 @@ stg_newArrayzh ( W_ n /* words */, gcptr init ) again: MAYBE_GC(again); - ("ptr" arr) = ccall allocateMutArrPtrs(MyCapability() "ptr", n, CCCS); + ("ptr" arr) = ccall allocateMutArrPtrs(MyCapability() "ptr", n, init "ptr", CCCS); if (arr == NULL) (likely: False) { jump stg_raisezh(HsIface_heapOverflow_closure(W_[ghc_hs_iface])); } - // Initialise all elements of the array with the value init - W_ p; - p = arr + SIZEOF_StgMutArrPtrs; - // Avoid the shift for `WDS(n)` in the inner loop - W_ limit; - limit = arr + SIZEOF_StgMutArrPtrs + WDS(n); - for: - if (p < limit) (likely: True) { - W_[p] = init; - p = p + WDS(1); - goto for; - } - return (arr); } @@ -496,24 +483,11 @@ stg_newSmallArrayzh ( W_ n /* words */, gcptr init ) again: MAYBE_GC(again); - ("ptr" arr) = ccall allocateSmallMutArrPtrs(MyCapability() "ptr", n, CCCS); + ("ptr" arr) = ccall allocateSmallMutArrPtrs(MyCapability() "ptr", n, init "ptr", CCCS); if (arr == NULL) (likely: False) { jump stg_raisezh(HsIface_heapOverflow_closure(W_[ghc_hs_iface])); } - // Initialise all elements of the array with the value init - W_ p; - p = arr + SIZEOF_StgSmallMutArrPtrs; - // Avoid the shift for `WDS(n)` in the inner loop - W_ limit; - limit = arr + SIZEOF_StgSmallMutArrPtrs + WDS(n); - for: - if (p < limit) (likely: True) { - W_[p] = init; - p = p + WDS(1); - goto for; - } - return (arr); } ===================================== rts/RtsFlags.c ===================================== @@ -209,6 +209,8 @@ void initRtsFlagsDefaults(void) RtsFlags.DebugFlags.numa = false; RtsFlags.DebugFlags.compact = false; RtsFlags.DebugFlags.continuation = false; + RtsFlags.DebugFlags.iomanager = false; + RtsFlags.DebugFlags.ipe = false; #if defined(PROFILING) RtsFlags.CcFlags.doCostCentres = COST_CENTRES_NONE; @@ -482,6 +484,7 @@ usage_text[] = { #if defined(DEBUG) " -Ds DEBUG: scheduler", " -Di DEBUG: interpreter", +" -DI DEBUG: IPE", " -Dw DEBUG: weak", " -DG DEBUG: gccafs", " -Dg DEBUG: gc", @@ -2311,6 +2314,9 @@ static void read_debug_flags(const char* arg) case 'o': RtsFlags.DebugFlags.iomanager = true; break; + case 'I': + RtsFlags.DebugFlags.ipe = true; + break; default: bad_option( arg ); } ===================================== rts/Threads.c ===================================== @@ -894,7 +894,7 @@ StgMutArrPtrs *listThreads(Capability *cap) } // Allocate a suitably-sized array... - StgMutArrPtrs *arr = allocateMutArrPtrs(cap, n_threads, cap->r.rCCCS); + StgMutArrPtrs *arr = allocateMutArrPtrs(cap, n_threads, NULL, cap->r.rCCCS); if (RTS_UNLIKELY(arr == NULL)) goto end; // Populate it... ===================================== rts/Trace.c ===================================== @@ -685,7 +685,8 @@ void traceHeapProfSampleString(const char *label, StgWord residency) void traceIPE(const InfoProvEnt *ipe) { #if defined(DEBUG) - if (RtsFlags.TraceFlags.tracing == TRACE_STDERR) { + if (RtsFlags.TraceFlags.tracing == TRACE_STDERR + && RtsFlags.DebugFlags.ipe) { ACQUIRE_LOCK(&trace_utx); char closure_desc_buf[CLOSURE_DESC_BUFFER_SIZE] = {}; ===================================== rts/Weak.c ===================================== @@ -146,7 +146,7 @@ scheduleFinalizers(Capability *cap, StgWeak *list) debugTrace(DEBUG_weak, "weak: batching %d finalizers", n); - StgMutArrPtrs *arr = allocateMutArrPtrs(cap, n, CCS_SYSTEM_OR_NULL); + StgMutArrPtrs *arr = allocateMutArrPtrs(cap, n, NULL, CCS_SYSTEM_OR_NULL); if (RTS_UNLIKELY(arr == NULL)) exitHeapOverflow(); // No write barrier needed here; this array is only going to referred to by this core. SET_INFO((StgClosure *) arr, &stg_MUT_ARR_PTRS_FROZEN_CLEAN_info); ===================================== rts/include/rts/Flags.h ===================================== @@ -118,6 +118,7 @@ typedef struct _DEBUG_FLAGS { bool compact; /* 'C' */ bool continuation; /* 'k' */ bool iomanager; /* 'o' */ + bool ipe; /* 'I' */ } DEBUG_FLAGS; /* See Note [Synchronization of flags and base APIs] */ ===================================== testsuite/driver/testglobals.py ===================================== @@ -72,6 +72,10 @@ class TestConfig: # Was the compiler compiled with -debug? self.debug_rts = False + # Were the compiler + libraries built with IPE-related options + # (e.g. -finfo-table-map, -fdistinct-constructor-tables)? + self.ghc_with_ipe = False + # Was the compiler compiled with LLVM? self.ghc_built_by_llvm = False ===================================== testsuite/driver/testlib.py ===================================== @@ -1074,6 +1074,9 @@ def have_profiling( ) -> bool: def have_threaded( ) -> bool: return config.ghc_with_threaded_rts +def ghc_with_ipe( ) -> bool: + return config.ghc_with_ipe + def in_tree_compiler( ) -> bool: return config.in_tree_compiler ===================================== testsuite/tests/interface-stability/ghc-experimental-exports.stdout ===================================== @@ -4454,6 +4454,22 @@ module Data.Tuple.Experimental where data Unit# = ... getSolo :: forall a. Solo a -> a +module GHC.Exception.Backtrace.Experimental where + -- Safety: None + type BacktraceMechanism :: * + data BacktraceMechanism = CostCentreBacktrace | HasCallStackBacktrace | ExecutionBacktrace | IPEBacktrace + type Backtraces :: * + data Backtraces = Backtraces {btrCostCentre :: GHC.Internal.Maybe.Maybe (GHC.Internal.Ptr.Ptr GHC.Internal.Stack.CCS.CostCentreStack), btrHasCallStack :: GHC.Internal.Maybe.Maybe GHC.Internal.Stack.Types.CallStack, btrExecutionStack :: GHC.Internal.Maybe.Maybe GHC.Internal.ExecutionStack.Internal.StackTrace, btrIpe :: GHC.Internal.Maybe.Maybe GHC.Internal.Stack.CloneStack.StackSnapshot} + type CollectExceptionAnnotationMechanism :: * + data CollectExceptionAnnotationMechanism = ... + collectBacktraces :: (?callStack::GHC.Internal.Stack.Types.CallStack) => GHC.Internal.Types.IO Backtraces + collectExceptionAnnotation :: GHC.Internal.Stack.Types.HasCallStack => GHC.Internal.Types.IO GHC.Internal.Exception.Context.SomeExceptionAnnotation + displayBacktraces :: Backtraces -> GHC.Internal.Base.String + getBacktraceMechanismState :: BacktraceMechanism -> GHC.Internal.Types.IO GHC.Internal.Types.Bool + getCollectExceptionAnnotationMechanism :: GHC.Internal.Types.IO CollectExceptionAnnotationMechanism + setBacktraceMechanismState :: BacktraceMechanism -> GHC.Internal.Types.Bool -> GHC.Internal.Types.IO () + setCollectExceptionAnnotation :: forall a. GHC.Internal.Exception.Context.ExceptionAnnotation a => (GHC.Internal.Stack.Types.HasCallStack => GHC.Internal.Types.IO a) -> GHC.Internal.Types.IO () + module GHC.PrimOps where -- Safety: Unsafe (*#) :: Int# -> Int# -> Int# @@ -11182,6 +11198,7 @@ instance GHC.Internal.Enum.Enum GHC.Internal.RTS.Flags.DoTrace -- Defined in ‘ instance GHC.Internal.Enum.Enum GHC.Internal.RTS.Flags.GiveGCStats -- Defined in ‘GHC.Internal.RTS.Flags’ instance GHC.Internal.Enum.Enum GHC.Internal.RTS.Flags.IoManagerFlag -- Defined in ‘GHC.Internal.RTS.Flags’ instance GHC.Internal.Enum.Enum GHC.Internal.IO.SubSystem.IoSubSystem -- Defined in ‘GHC.Internal.IO.SubSystem’ +instance GHC.Internal.Exception.Context.ExceptionAnnotation GHC.Internal.Exception.Backtrace.Backtraces -- Defined in ‘GHC.Internal.Exception.Backtrace’ instance forall a. GHC.Internal.Float.Floating a => GHC.Internal.Float.Floating (GHC.Internal.Data.Ord.Down a) -- Defined in ‘GHC.Internal.Data.Ord’ instance forall a. GHC.Internal.Float.RealFloat a => GHC.Internal.Float.RealFloat (GHC.Internal.Data.Ord.Down a) -- Defined in ‘GHC.Internal.Data.Ord’ instance forall a. GHC.Internal.Foreign.Storable.Storable a => GHC.Internal.Foreign.Storable.Storable (GHC.Internal.Data.Ord.Down a) -- Defined in ‘GHC.Internal.Data.Ord’ ===================================== testsuite/tests/interface-stability/ghc-experimental-exports.stdout-mingw32 ===================================== @@ -4454,6 +4454,22 @@ module Data.Tuple.Experimental where data Unit# = ... getSolo :: forall a. Solo a -> a +module GHC.Exception.Backtrace.Experimental where + -- Safety: None + type BacktraceMechanism :: * + data BacktraceMechanism = CostCentreBacktrace | HasCallStackBacktrace | ExecutionBacktrace | IPEBacktrace + type Backtraces :: * + data Backtraces = Backtraces {btrCostCentre :: GHC.Internal.Maybe.Maybe (GHC.Internal.Ptr.Ptr GHC.Internal.Stack.CCS.CostCentreStack), btrHasCallStack :: GHC.Internal.Maybe.Maybe GHC.Internal.Stack.Types.CallStack, btrExecutionStack :: GHC.Internal.Maybe.Maybe GHC.Internal.ExecutionStack.Internal.StackTrace, btrIpe :: GHC.Internal.Maybe.Maybe GHC.Internal.Stack.CloneStack.StackSnapshot} + type CollectExceptionAnnotationMechanism :: * + data CollectExceptionAnnotationMechanism = ... + collectBacktraces :: (?callStack::GHC.Internal.Stack.Types.CallStack) => GHC.Internal.Types.IO Backtraces + collectExceptionAnnotation :: GHC.Internal.Stack.Types.HasCallStack => GHC.Internal.Types.IO GHC.Internal.Exception.Context.SomeExceptionAnnotation + displayBacktraces :: Backtraces -> GHC.Internal.Base.String + getBacktraceMechanismState :: BacktraceMechanism -> GHC.Internal.Types.IO GHC.Internal.Types.Bool + getCollectExceptionAnnotationMechanism :: GHC.Internal.Types.IO CollectExceptionAnnotationMechanism + setBacktraceMechanismState :: BacktraceMechanism -> GHC.Internal.Types.Bool -> GHC.Internal.Types.IO () + setCollectExceptionAnnotation :: forall a. GHC.Internal.Exception.Context.ExceptionAnnotation a => (GHC.Internal.Stack.Types.HasCallStack => GHC.Internal.Types.IO a) -> GHC.Internal.Types.IO () + module GHC.PrimOps where -- Safety: Unsafe (*#) :: Int# -> Int# -> Int# @@ -11185,6 +11201,7 @@ instance GHC.Internal.Enum.Enum GHC.Internal.RTS.Flags.DoTrace -- Defined in ‘ instance GHC.Internal.Enum.Enum GHC.Internal.RTS.Flags.GiveGCStats -- Defined in ‘GHC.Internal.RTS.Flags’ instance GHC.Internal.Enum.Enum GHC.Internal.RTS.Flags.IoManagerFlag -- Defined in ‘GHC.Internal.RTS.Flags’ instance GHC.Internal.Enum.Enum GHC.Internal.IO.SubSystem.IoSubSystem -- Defined in ‘GHC.Internal.IO.SubSystem’ +instance GHC.Internal.Exception.Context.ExceptionAnnotation GHC.Internal.Exception.Backtrace.Backtraces -- Defined in ‘GHC.Internal.Exception.Backtrace’ instance forall a. GHC.Internal.Float.Floating a => GHC.Internal.Float.Floating (GHC.Internal.Data.Ord.Down a) -- Defined in ‘GHC.Internal.Data.Ord’ instance forall a. GHC.Internal.Float.RealFloat a => GHC.Internal.Float.RealFloat (GHC.Internal.Data.Ord.Down a) -- Defined in ‘GHC.Internal.Data.Ord’ instance forall a. GHC.Internal.Foreign.Storable.Storable a => GHC.Internal.Foreign.Storable.Storable (GHC.Internal.Data.Ord.Down a) -- Defined in ‘GHC.Internal.Data.Ord’ ===================================== testsuite/tests/rts/Makefile ===================================== @@ -140,7 +140,7 @@ T20199: .PHONY: EventlogOutput_IPE EventlogOutput_IPE: "$(TEST_HC)" $(TEST_HC_OPTS) -debug -finfo-table-map -v0 EventlogOutput.hs - ./EventlogOutput +RTS -va 2> EventlogOutput_IPE.stderr.log + ./EventlogOutput +RTS -va -DI 2> EventlogOutput_IPE.stderr.log grep "IPE:" EventlogOutput_IPE.stderr.log .PHONY: T23142 ===================================== testsuite/tests/rts/all.T ===================================== @@ -535,6 +535,7 @@ test('T13676', test('InitEventLogging', [ only_ways(['normal']) , extra_run_opts('+RTS -RTS') + , when(ghc_with_ipe(), skip) # IPE builds can change eventlog writer call counts. , req_c ], compile_and_run, ['InitEventLogging_c.c']) @@ -588,6 +589,7 @@ test('cloneThreadStack', [req_c, only_ways(['threaded1']), extra_ways(['threaded test('decodeMyStack', [ omit_ghci, js_broken(22261) # cloneMyStack# not yet implemented + , when(ghc_with_ipe(), skip) # IPE builds can change decoded stack output. ], compile_and_run, ['-finfo-table-map']) # Options: @@ -595,6 +597,7 @@ test('decodeMyStack', test('decodeMyStack_underflowFrames', [ extra_run_opts('+RTS -kc8K -RTS') , omit_ghci, js_broken(22261) # cloneMyStack# not yet implemented + , when(ghc_with_ipe(), skip) # IPE builds can change decoded stack layout/length. ], compile_and_run, ['-finfo-table-map -rtsopts']) # -finfo-table-map intentionally missing @@ -602,6 +605,7 @@ test('decodeMyStack_emptyListForMissingFlag', [ ignore_stdout , ignore_stderr , js_broken(22261) # cloneMyStack# not yet implemented + , when(ghc_with_ipe(), skip) # IPE builds can populate IPE info even without -finfo-table-map on this module. ], compile_and_run, ['']) # Tests RTS flag parsing. Skipped on JS as it uses a distinct RTS. @@ -646,7 +650,7 @@ test('T25280', [unless(opsys('linux'),skip),req_process,js_skip], compile_and_ru test('T25560', [req_c_rts, ignore_stderr], compile_and_run, ['']) test('TestProddableBlockSet', [req_c_rts], multimod_compile_and_run, ['TestProddableBlockSet.c', '-no-hs-main']) -test('T22859', +test('T22859', [js_skip, # This test is vulnerable to changes in allocation behaviour, so we disable it in some ways when(arch('wasm32'), skip), ===================================== testsuite/tests/rts/ipe/all.T ===================================== @@ -8,7 +8,7 @@ test('ipeMap', [extra_files(['ipe_lib.c', 'ipe_lib.h']), c_src, omit_ghci], comp test('ipeEventLog', [ c_src, extra_files(['ipe_lib.c', 'ipe_lib.h']), - extra_run_opts('+RTS -va -RTS'), + extra_run_opts('+RTS -va -DI -RTS'), grep_errmsg('table_name_'), only_ways(debug_ways), normalise_errmsg_fun(noCapabilityOutputFilter), @@ -24,7 +24,7 @@ test('ipeEventLog', test('ipeEventLog_fromMap', [ c_src, extra_files(['ipe_lib.c', 'ipe_lib.h']), - extra_run_opts('+RTS -va -RTS'), + extra_run_opts('+RTS -va -DI -RTS'), grep_errmsg('table_name_'), only_ways(debug_ways), normalise_errmsg_fun(noCapabilityOutputFilter), @@ -34,4 +34,3 @@ test('ipeEventLog_fromMap', when(opsys('darwin'), fragile(0)) ], compile_and_run, ['ipe_lib.c']) - View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/ba24973bcdffb9edf196950ad1633c… -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/ba24973bcdffb9edf196950ad1633c… You're receiving this email because of your account on gitlab.haskell.org.

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[Git][ghc/ghc][master] hadrian: Add ghc-{experimental,internal}.cabal to the list of dependencies of the doc target
by Marge Bot (＠marge-bot) 22 Jan '26

22 Jan '26

Marge Bot pushed to branch master at Glasgow Haskell Compiler / GHC Commits: 1b490f5a by Zubin Duggal at 2026-01-22T09:00:53-05:00 hadrian: Add ghc-{experimental,internal}.cabal to the list of dependencies of the doc target We need these files to detect the version of these libraries Fixes #26738 - - - - - 1 changed file: - hadrian/src/Rules/Documentation.hs Changes: ===================================== hadrian/src/Rules/Documentation.hs ===================================== @@ -74,6 +74,8 @@ needDocDeps = do let templatedCabalFiles = map pkgCabalFile [ ghcBoot , ghcBootTh + , ghcExperimental + , ghcInternal , ghci , compiler , ghcHeap View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/1b490f5a7bbdb1441948241e6089b31… -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/1b490f5a7bbdb1441948241e6089b31… You're receiving this email because of your account on gitlab.haskell.org.

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