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[Git][ghc/ghc][wip/T26009] 7 commits: rts/linker: Factor out ProddableBlocks machinery
by Ben Gamari (＠bgamari) 19 May '25

19 May '25

Ben Gamari pushed to branch wip/T26009 at Glasgow Haskell Compiler / GHC Commits: 2921131c by Ben Gamari at 2025-05-19T15:55:32-04:00 rts/linker: Factor out ProddableBlocks machinery - - - - - e6e69dba by Ben Gamari at 2025-05-19T15:55:32-04:00 rts/linker: Improve efficiency of proddable blocks structure Previously the linker's "proddable blocks" check relied on a simple linked list of spans. This resulted in extremely poor complexity while linking objects with lots of small sections (e.g. objects built with split sections). Rework the mechanism to instead use a simple interval set implemented via binary search. Fixes #26009. - - - - - 915902fc by Ben Gamari at 2025-05-19T15:55:32-04:00 testsuite: Add simple functional test for ProddableBlockSet - - - - - 1f38e273 by Ben Gamari at 2025-05-19T15:55:32-04:00 rts/linker/PEi386: Drop check for LOAD_LIBRARY_SEARCH_*_DIRS The `LOAD_LIBRARY_SEARCH_USER_DIRS` and `LOAD_LIBRARY_SEARCH_DEFAULT_DIRS` were introduced in Windows Vista and have been available every since. As we no longer support Windows XP we can drop this check. Addresses #26009. - - - - - facf379b by Ben Gamari at 2025-05-19T15:55:33-04:00 rts/linker/PEi386: Clean up code style - - - - - 30a7dc99 by Ben Gamari at 2025-05-19T15:56:09-04:00 rts/Hash: Factor out hashBuffer This is a useful helper which can be used for non-strings as well. - - - - - 5cfcf0f9 by Ben Gamari at 2025-05-19T15:58:03-04:00 rts/linker/PEi386: Don't repeated load DLLs Previously every DLL-imported symbol would result in a call to `LoadLibraryEx`. This ended up constituting over 40% of the runtime of `ghc --interactive -e 42` on Windows. Avoid this by maintaining a hash-set of loaded DLL names, skipping the call if we have already loaded the requested DLL. Addresses #26009. - - - - - 13 changed files: - libffi-tarballs - rts/Hash.c - rts/Hash.h - rts/Linker.c - rts/LinkerInternals.h - rts/linker/Elf.c - rts/linker/MachO.c - rts/linker/PEi386.c - + rts/linker/ProddableBlocks.c - + rts/linker/ProddableBlocks.h - rts/rts.cabal - + testsuite/tests/rts/TestProddableBlockSet.c - testsuite/tests/rts/all.T Changes: ===================================== libffi-tarballs ===================================== @@ -1 +1 @@ -Subproject commit ac7fa3132d382056837cad297ab4c66418febb69 +Subproject commit cb280851187d7b509d341be7b50c9a239810feb0 ===================================== rts/Hash.c ===================================== @@ -94,13 +94,13 @@ hashWord(const HashTable *table, StgWord key) } int -hashStr(const HashTable *table, StgWord w) +hashBuffer(const HashTable *table, const void *buf, size_t len) { - const char *key = (char*) w; + const char *key = (char*) buf; #if WORD_SIZE_IN_BITS == 64 - StgWord h = XXH3_64bits_withSeed (key, strlen(key), 1048583); + StgWord h = XXH3_64bits_withSeed (key, len, 1048583); #else - StgWord h = XXH32 (key, strlen(key), 1048583); + StgWord h = XXH32 (key, len, 1048583); #endif /* Mod the size of the hash table (a power of 2) */ @@ -114,6 +114,13 @@ hashStr(const HashTable *table, StgWord w) return bucket; } +int +hashStr(const HashTable *table, StgWord w) +{ + const char *key = (char*) w; + return hashBuffer(table, key, strlen(key)); +} + STATIC_INLINE int compareWord(StgWord key1, StgWord key2) { ===================================== rts/Hash.h ===================================== @@ -69,6 +69,10 @@ void * removeStrHashTable ( StrHashTable *table, const char * key, */ typedef int HashFunction(const HashTable *table, StgWord key); typedef int CompareFunction(StgWord key1, StgWord key2); + +// Helper for implementing hash functions +int hashBuffer(const HashTable *table, const void *buf, size_t len); + int hashWord(const HashTable *table, StgWord key); int hashStr(const HashTable *table, StgWord w); void insertHashTable_ ( HashTable *table, StgWord key, @@ -79,6 +83,7 @@ void * removeHashTable_ ( HashTable *table, StgWord key, const void *data, HashFunction f, CompareFunction cmp ); + /* Freeing hash tables */ void freeHashTable ( HashTable *table, void (*freeDataFun)(void *) ); ===================================== rts/Linker.c ===================================== @@ -1194,7 +1194,7 @@ void freeObjectCode (ObjectCode *oc) stgFree(oc->sections); } - freeProddableBlocks(oc); + freeProddableBlocks(&oc->proddables); freeSegments(oc); /* Free symbol_extras. On x86_64 Windows, symbol_extras are allocated @@ -1279,7 +1279,7 @@ mkOc( ObjectType type, pathchar *path, char *image, int imageSize, oc->sections = NULL; oc->n_segments = 0; oc->segments = NULL; - oc->proddables = NULL; + initProddableBlockSet(&oc->proddables); oc->foreign_exports = NULL; #if defined(NEED_SYMBOL_EXTRAS) oc->symbol_extras = NULL; @@ -1834,50 +1834,6 @@ OStatus getObjectLoadStatus (pathchar *path) return r; } -/* ----------------------------------------------------------------------------- - * Sanity checking. For each ObjectCode, maintain a list of address ranges - * which may be prodded during relocation, and abort if we try and write - * outside any of these. - */ -void -addProddableBlock ( ObjectCode* oc, void* start, int size ) -{ - ProddableBlock* pb - = stgMallocBytes(sizeof(ProddableBlock), "addProddableBlock"); - - IF_DEBUG(linker, debugBelch("addProddableBlock: %p %p %d\n", oc, start, size)); - ASSERT(size > 0); - pb->start = start; - pb->size = size; - pb->next = oc->proddables; - oc->proddables = pb; -} - -void -checkProddableBlock (ObjectCode *oc, void *addr, size_t size ) -{ - ProddableBlock* pb; - - for (pb = oc->proddables; pb != NULL; pb = pb->next) { - char* s = (char*)(pb->start); - char* e = s + pb->size; - char* a = (char*)addr; - if (a >= s && (a+size) <= e) return; - } - barf("checkProddableBlock: invalid fixup in runtime linker: %p", addr); -} - -void freeProddableBlocks (ObjectCode *oc) -{ - ProddableBlock *pb, *next; - - for (pb = oc->proddables; pb != NULL; pb = next) { - next = pb->next; - stgFree(pb); - } - oc->proddables = NULL; -} - /* ----------------------------------------------------------------------------- * Section management. */ ===================================== rts/LinkerInternals.h ===================================== @@ -12,6 +12,7 @@ #include "RtsSymbols.h" #include "Hash.h" #include "linker/M32Alloc.h" +#include "linker/ProddableBlocks.h" #if RTS_LINKER_USE_MMAP #include <sys/mman.h> @@ -175,14 +176,6 @@ struct _Section { struct SectionFormatInfo* info; }; -typedef - struct _ProddableBlock { - void* start; - int size; - struct _ProddableBlock* next; - } - ProddableBlock; - typedef struct _Segment { void *start; /* page aligned start address of a segment */ size_t size; /* page rounded size of a segment */ @@ -328,7 +321,7 @@ struct _ObjectCode { /* SANITY CHECK ONLY: a list of the only memory regions which may safely be prodded during relocation. Any attempt to prod outside one of these is an error in the linker. */ - ProddableBlock* proddables; + ProddableBlockSet proddables; #if defined(NEED_SYMBOL_EXTRAS) SymbolExtra *symbol_extras; @@ -434,10 +427,6 @@ void exitLinker( void ); void freeObjectCode (ObjectCode *oc); SymbolAddr* loadSymbol(SymbolName *lbl, RtsSymbolInfo *pinfo); -void addProddableBlock ( ObjectCode* oc, void* start, int size ); -void checkProddableBlock (ObjectCode *oc, void *addr, size_t size ); -void freeProddableBlocks (ObjectCode *oc); - void addSection (Section *s, SectionKind kind, SectionAlloc alloc, void* start, StgWord size, StgWord mapped_offset, void* mapped_start, StgWord mapped_size); ===================================== rts/linker/Elf.c ===================================== @@ -924,7 +924,7 @@ ocGetNames_ELF ( ObjectCode* oc ) oc->sections[i].info->stubs = NULL; #endif - addProddableBlock(oc, start, size); + addProddableBlock(&oc->proddables, start, size); } else { addSection(&oc->sections[i], kind, alloc, oc->image+offset, size, 0, 0, 0); @@ -1272,7 +1272,7 @@ do_Elf_Rel_relocations ( ObjectCode* oc, char* ehdrC, debugBelch("Reloc: P = %p S = %p A = %p type=%d\n", (void*)P, (void*)S, (void*)A, reloc_type )); #if defined(DEBUG) - checkProddableBlock ( oc, pP, sizeof(Elf_Word) ); + checkProddableBlock ( &oc->proddables, pP, sizeof(Elf_Word) ); #else (void) pP; /* suppress unused varialbe warning in non-debug build */ #endif @@ -1684,7 +1684,7 @@ do_Elf_Rela_relocations ( ObjectCode* oc, char* ehdrC, #if defined(DEBUG) IF_DEBUG(linker_verbose,debugBelch("Reloc: P = %p S = %p A = %p\n", (void*)P, (void*)S, (void*)A )); - checkProddableBlock(oc, (void*)P, sizeof(Elf_Word)); + checkProddableBlock(&oc->proddables, (void*)P, sizeof(Elf_Word)); #endif #if defined(powerpc_HOST_ARCH) || defined(x86_64_HOST_ARCH) ===================================== rts/linker/MachO.c ===================================== @@ -253,7 +253,7 @@ resolveImports( return 0; } - checkProddableBlock(oc, + checkProddableBlock(&oc->proddables, ((void**)(oc->image + sect->offset)) + i, sizeof(void *)); ((void**)(oc->image + sect->offset))[i] = addr; @@ -287,7 +287,7 @@ decodeAddend(ObjectCode * oc, Section * section, MachORelocationInfo * ri) { /* the instruction. It is 32bit wide */ uint32_t * p = (uint32_t*)((uint8_t*)section->start + ri->r_address); - checkProddableBlock(oc, (void*)p, 1 << ri->r_length); + checkProddableBlock(&oc->proddables, (void*)p, 1 << ri->r_length); switch(ri->r_type) { case ARM64_RELOC_UNSIGNED: { @@ -364,7 +364,7 @@ encodeAddend(ObjectCode * oc, Section * section, MachORelocationInfo * ri, int64_t addend) { uint32_t * p = (uint32_t*)((uint8_t*)section->start + ri->r_address); - checkProddableBlock(oc, (void*)p, 1 << ri->r_length); + checkProddableBlock(&oc->proddables, (void*)p, 1 << ri->r_length); switch (ri->r_type) { case ARM64_RELOC_UNSIGNED: { @@ -788,7 +788,7 @@ relocateSection(ObjectCode* oc, int curSection) default: barf("Unknown size."); } - checkProddableBlock(oc,thingPtr,relocLenBytes); + checkProddableBlock(&oc->proddables,thingPtr,relocLenBytes); /* * With SIGNED_N the relocation is not at the end of the @@ -1034,9 +1034,9 @@ relocateSection(ObjectCode* oc, int curSection) */ if (0 == reloc->r_extern) { if (reloc->r_pcrel) { - checkProddableBlock(oc, (void *)((char *)thing + baseValue), 1); + checkProddableBlock(&oc->proddables, (void *)((char *)thing + baseValue), 1); } else { - checkProddableBlock(oc, (void *)thing, 1); + checkProddableBlock(&oc->proddables, (void *)thing, 1); } } @@ -1343,7 +1343,7 @@ ocGetNames_MachO(ObjectCode* oc) secArray[sec_idx].info->stub_size = 0; secArray[sec_idx].info->stubs = NULL; #endif - addProddableBlock(oc, start, section->size); + addProddableBlock(&oc->proddables, start, section->size); } curMem = (char*) secMem + section->size; ===================================== rts/linker/PEi386.c ===================================== @@ -427,8 +427,53 @@ const int default_alignment = 8; the pointer as a redirect. Essentially it's a DATA DLL reference. */ const void* __rts_iob_func = (void*)&__acrt_iob_func; +/* + * Note [Avoiding repeated DLL loading] + * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + * As LoadLibraryEx tends to be expensive and addDLL_PEi386 is called on every + * DLL-imported symbol, we use a hash-set to keep track of which DLLs have + * already been loaded. This hash-set is keyed on the dll_name passed to + * addDLL_PEi386 and serves as a quick check to avoid repeated calls to + * LoadLibraryEx for the identical DLL. See #26009. + */ + +typedef struct { + HashTable *hash; +} LoadedDllSet; + +LoadedDllSet loaded_dll_set; + +void initLoadedDllSet(LoadedDllSet *set) { + set->hash = allocHashTable(); +} + +int hash_path(const HashTable *table, StgWord w) +{ + const pathchar *key = (pathchar*) w; + return hashBuffer(table, key, sizeof(pathchar) * wcslen(key)); +} + +int compare_path(StgWord key1, StgWord key2) +{ + return wscmp((pathchar*) key1, (pathchar*) key2); +} + +void addLoadedDll(LoadedDllSet *set, pathchar *dll_name) +{ + insertHashTable_(set->hash, (StgWord) dll_name, (void*) 1, hash_path); +} + +bool isDllLoaded(LoadedDllSet *set, pathchar *dll_name) +{ + void * result = lookupHashTable_(set->hash, (StgWord) dll_name, hash_path, compare_path); + return result != NULL; +} + + void initLinker_PEi386(void) { + initLoadedDllSet(&loaded_dll_set); + if (!ghciInsertSymbolTable(WSTR("(GHCi/Ld special symbols)"), symhash, "__image_base__", GetModuleHandleW (NULL), HS_BOOL_TRUE, @@ -440,10 +485,11 @@ void initLinker_PEi386(void) addDLLHandle(WSTR("*.exe"), GetModuleHandle(NULL)); #endif - /* Register the cleanup routine as an exit handler, this gives other exit handlers - a chance to run which may need linker information. Exit handlers are ran in - reverse registration order so this needs to be before the linker loads anything. */ - atexit (exitLinker_PEi386); + /* Register the cleanup routine as an exit handler, this gives other exit handlers + * a chance to run which may need linker information. Exit handlers are ran in + * reverse registration order so this needs to be before the linker loads anything. + */ + atexit (exitLinker_PEi386); } void exitLinker_PEi386(void) @@ -798,12 +844,12 @@ uint8_t* getSymShortName ( COFF_HEADER_INFO *info, COFF_symbol* sym ) const char * addDLL_PEi386( pathchar *dll_name, HINSTANCE *loaded ) { - /* ------------------- Win32 DLL loader ------------------- */ - - pathchar* buf; - HINSTANCE instance; + /* ------------------- Win32 DLL loader ------------------- */ + IF_DEBUG(linker, debugBelch("addDLL; dll_name = `%" PATH_FMT "'\n", dll_name)); - IF_DEBUG(linker, debugBelch("addDLL; dll_name = `%" PATH_FMT "'\n", dll_name)); + if (isDllLoaded(&loaded_dll_set, dll_name)) { + return NULL; + } /* The file name has no suffix (yet) so that we can try both foo.dll and foo.drv @@ -816,35 +862,23 @@ addDLL_PEi386( pathchar *dll_name, HINSTANCE *loaded ) extension. */ size_t bufsize = pathlen(dll_name) + 10; - buf = stgMallocBytes(bufsize * sizeof(wchar_t), "addDLL"); + pathchar *buf = stgMallocBytes(bufsize * sizeof(wchar_t), "addDLL"); /* These are ordered by probability of success and order we'd like them. */ const wchar_t *formats[] = { L"%ls.DLL", L"%ls.DRV", L"lib%ls.DLL", L"%ls" }; const DWORD flags[] = { LOAD_LIBRARY_SEARCH_USER_DIRS | LOAD_LIBRARY_SEARCH_DEFAULT_DIRS, 0 }; - int cFormat, cFlag; - int flags_start = 1; /* Assume we don't support the new API. */ - - /* Detect if newer API are available, if not, skip the first flags entry. */ - if (GetProcAddress((HMODULE)LoadLibraryW(L"Kernel32.DLL"), "AddDllDirectory")) { - flags_start = 0; - } - /* Iterate through the possible flags and formats. */ - for (cFlag = flags_start; cFlag < 2; cFlag++) - { - for (cFormat = 0; cFormat < 4; cFormat++) - { + HINSTANCE instance; + for (int cFlag = 0; cFlag < 2; cFlag++) { + for (int cFormat = 0; cFormat < 4; cFormat++) { snwprintf(buf, bufsize, formats[cFormat], dll_name); instance = LoadLibraryExW(buf, NULL, flags[cFlag]); if (instance == NULL) { - if (GetLastError() != ERROR_MOD_NOT_FOUND) - { + if (GetLastError() != ERROR_MOD_NOT_FOUND) { goto error; } - } - else - { + } else { break; /* We're done. DLL has been loaded. */ } } @@ -855,6 +889,7 @@ addDLL_PEi386( pathchar *dll_name, HINSTANCE *loaded ) goto error; } + addLoadedDll(&loaded_dll_set, dll_name); addDLLHandle(buf, instance); if (loaded) { *loaded = instance; @@ -1658,7 +1693,7 @@ ocGetNames_PEi386 ( ObjectCode* oc ) } addSection(section, kind, SECTION_NOMEM, start, sz, 0, 0, 0); - addProddableBlock(oc, oc->sections[i].start, sz); + addProddableBlock(&oc->proddables, oc->sections[i].start, sz); } /* Copy exported symbols into the ObjectCode. */ @@ -1690,7 +1725,7 @@ ocGetNames_PEi386 ( ObjectCode* oc ) SECTIONKIND_RWDATA, SECTION_MALLOC, bss, globalBssSize, 0, 0, 0); IF_DEBUG(linker_verbose, debugBelch("bss @ %p %" FMT_Word "\n", bss, globalBssSize)); - addProddableBlock(oc, bss, globalBssSize); + addProddableBlock(&oc->proddables, bss, globalBssSize); } else { addSection(&oc->sections[oc->n_sections-1], SECTIONKIND_OTHER, SECTION_NOMEM, NULL, 0, 0, 0, 0); @@ -2067,13 +2102,13 @@ ocResolve_PEi386 ( ObjectCode* oc ) IF_DEBUG(linker_verbose, debugBelch("S=%zx\n", S)); /* All supported relocations write at least 4 bytes */ - checkProddableBlock(oc, pP, 4); + checkProddableBlock(&oc->proddables, pP, 4); switch (reloc->Type) { #if defined(x86_64_HOST_ARCH) case 1: /* R_X86_64_64 (ELF constant 1) - IMAGE_REL_AMD64_ADDR64 (PE constant 1) */ { uint64_t A; - checkProddableBlock(oc, pP, 8); + checkProddableBlock(&oc->proddables, pP, 8); A = *(uint64_t*)pP; *(uint64_t *)pP = S + A; break; @@ -2114,7 +2149,7 @@ ocResolve_PEi386 ( ObjectCode* oc ) { /* mingw will emit this for a pc-rel 64 relocation */ uint64_t A; - checkProddableBlock(oc, pP, 8); + checkProddableBlock(&oc->proddables, pP, 8); A = *(uint64_t*)pP; *(uint64_t *)pP = S + A - (intptr_t)pP; break; ===================================== rts/linker/ProddableBlocks.c ===================================== @@ -0,0 +1,130 @@ +/* ----------------------------------------------------------------------------- + * + * (c) The GHC Team, 2025 + * + * RTS Object Linker + * + * ---------------------------------------------------------------------------*/ + + +/* + * Sanity checking. For each ObjectCode, maintain a list of address ranges + * which may be prodded during relocation, and abort if we try and write + * outside any of these. + */ + +#include "Rts.h" +#include "RtsUtils.h" +#include "linker/ProddableBlocks.h" + +#include <stdlib.h> +#include <string.h> + +typedef struct _ProddableBlock { + uintptr_t start; // inclusive + uintptr_t end; // inclusive +} ProddableBlock; + +void +initProddableBlockSet ( ProddableBlockSet* set ) +{ + set->data = NULL; + set->capacity = 0; + set->size = 0; +} + +void +freeProddableBlocks (ProddableBlockSet *set) +{ + stgFree(set->data); + set->data = NULL; + set->size = 0; + set->capacity = 0; +} + +// Binary search for the first interval with start >= value. Returns index or +// size if none. +static size_t +findLower(const ProddableBlockSet *set, uintptr_t value) +{ + size_t l = 0; + size_t r = set->size; + while (l < r) { + size_t mid = l + (r - l) / 2; + if (set->data[mid].start < value) { + l = mid + 1; + } else { + r = mid; + } + } + return l; +} + +// Check whether a given value is a member of the set. +bool +containsSpan ( const ProddableBlockSet *set, uintptr_t start, uintptr_t end ) +{ + size_t i = findLower(set, start+1); + return i > 0 + && set->data[i-1].start <= start + && end <= set->data[i-1].end; +} + +void +checkProddableBlock (const ProddableBlockSet *set, void *addr, size_t size ) +{ + if (! containsSpan(set, (uintptr_t) addr, (uintptr_t) addr+size)) { + barf("checkProddableBlock: invalid fixup in runtime linker: %p", addr); + } +} + +// Ensure capacity for at least new_capacity intervals +static void +ensureCapacity(ProddableBlockSet *set, size_t new_capacity) { + if (new_capacity > set->capacity) { + size_t cap = set->capacity ? set->capacity * 2 : 4; + if (cap < new_capacity) { + cap = new_capacity; + } + ProddableBlock *tmp = stgReallocBytes(set->data, cap * sizeof(ProddableBlock), "addProddableBlock"); + set->data = tmp; + set->capacity = cap; + } +} + +void +addProddableBlock ( ProddableBlockSet* set, void* start_ptr, size_t size ) +{ + const uintptr_t start = (uintptr_t) start_ptr; + const uintptr_t end = (uintptr_t) start + size; + size_t i = findLower(set, start); + + // check previous interval if it is overlapping or adjacent + if (i > 0 && start <= set->data[i-1].end + 1) { + // merge with left interval + i--; + if (end > set->data[i].end) { + set->data[i].end = end; + } + } else { + // insert new interval + ensureCapacity(set, set->size + 1); + memmove(&set->data[i+1], &set->data[i], sizeof(ProddableBlock) * (set->size - i)); + set->data[i].start = start; + set->data[i].end = end; + set->size++; + } + + // coalesce overlaps on right + size_t j = i; + while (j < set->size && set->data[j].start <= set->data[i].end + 1) { + set->data[i].end = set->data[j].end; + j++; + } + + if (j != i) { + memmove(&set->data[i+1], &set->data[j], sizeof(ProddableBlock) * (set->size - j)); + set->size -= j - i - 1; + } +} + ===================================== rts/linker/ProddableBlocks.h ===================================== @@ -0,0 +1,38 @@ +/* ----------------------------------------------------------------------------- + * + * (c) The GHC Team, 2025 + * + * RTS Object Linker + * + * ---------------------------------------------------------------------------*/ + +#pragma once + +#include <stdbool.h> +#include <stddef.h> +#include <stdint.h> + +// An interval set on uintptr_t. +struct _ProddableBlock; + +typedef struct { + size_t size; + size_t capacity; + // sorted list of disjoint (start,end) pairs + struct _ProddableBlock *data; +} ProddableBlockSet; + +void initProddableBlockSet ( ProddableBlockSet* set ); + +// Insert an interval. +void addProddableBlock ( ProddableBlockSet* set, void* start, size_t size ); + +// Check that an address belongs to the set. +void checkProddableBlock (const ProddableBlockSet *set, void *addr, size_t size ); + + +// Free a set. +void freeProddableBlocks (ProddableBlockSet *set); + +// For testing. +bool containsSpan ( const ProddableBlockSet *set, uintptr_t start, uintptr_t end ); ===================================== rts/rts.cabal ===================================== @@ -491,6 +491,7 @@ library linker/MachO.c linker/macho/plt.c linker/macho/plt_aarch64.c + linker/ProddableBlocks.c linker/PEi386.c linker/SymbolExtras.c linker/elf_got.c ===================================== testsuite/tests/rts/TestProddableBlockSet.c ===================================== @@ -0,0 +1,33 @@ +#include <assert.h> +#include <stdbool.h> +#include <stdint.h> +#include <stddef.h> + +// Excerpted from ProddableBlocks.h +typedef struct { + size_t size; + size_t capacity; + // sorted list of disjoint (start,end) pairs + struct _ProddableBlock *data; +} ProddableBlockSet; + +void initProddableBlockSet ( ProddableBlockSet* set ); +void addProddableBlock ( ProddableBlockSet* set, void* start, size_t size ); +bool containsSpan ( const ProddableBlockSet *set, uintptr_t start, uintptr_t end ); + +int main () { + ProddableBlockSet set; + initProddableBlockSet(&set); + addProddableBlock(&set, (void*) 0x20, 0x10); + addProddableBlock(&set, (void*) 0x30, 0x10); + addProddableBlock(&set, (void*) 0x100, 0x10); + + assert( containsSpan(&set, 0x20, 0x30)); + assert( containsSpan(&set, 0x30, 0x29)); + assert(!containsSpan(&set, 0x30, 0x49)); + assert(!containsSpan(&set, 0x60, 0x70)); + assert(!containsSpan(&set, 0x90, 0x110)); + assert( containsSpan(&set, 0x100, 0x101)); + return 0; +} + ===================================== testsuite/tests/rts/all.T ===================================== @@ -641,3 +641,5 @@ test('T25280', [unless(opsys('linux'),skip),req_process,js_skip], compile_and_ru # N.B. This will likely issue a warning on stderr but we merely care that the # program doesn't crash. test('T25560', [req_c_rts, ignore_stderr], compile_and_run, ['']) + +test('TestProddableBlockSet', [req_c_rts], multimod_compile_and_run, ['TestProddableBlockSet.c', '-no-hs-main']) View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/af7b73daab5d9c6b3064d3ae9d82c6… -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/af7b73daab5d9c6b3064d3ae9d82c6… You're receiving this email because of your account on gitlab.haskell.org.

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[Git][ghc/ghc][wip/T26009] 2 commits: rts/linker/PEi386: Don't repeated load DLLs
by Ben Gamari (＠bgamari) 19 May '25

19 May '25

Ben Gamari pushed to branch wip/T26009 at Glasgow Haskell Compiler / GHC Commits: 7973f903 by Ben Gamari at 2025-05-19T15:34:19-04:00 rts/linker/PEi386: Don't repeated load DLLs Previously every DLL-imported symbol would result in a call to `LoadLibraryEx`. This ended up constituting over 40% of the runtime of `ghc --interactive -e 42` on Windows. Avoid this by maintaining a hash-set of loaded DLL names, skipping the call if we have already loaded the requested DLL. Addresses #26009. - - - - - af7b73da by Ben Gamari at 2025-05-19T15:39:26-04:00 fixup! rts/Hash: Factor out hashBuffer - - - - - 3 changed files: - rts/Hash.c - rts/Hash.h - rts/linker/PEi386.c Changes: ===================================== rts/Hash.c ===================================== @@ -94,9 +94,9 @@ hashWord(const HashTable *table, StgWord key) } int -hashBuffer(const void *buf, size_t len) +hashBuffer(const HashTable *table, const void *buf, size_t len) { - const char *key = (char*) w; + const char *key = (char*) buf; #if WORD_SIZE_IN_BITS == 64 StgWord h = XXH3_64bits_withSeed (key, strlen(key), 1048583); #else @@ -117,7 +117,7 @@ hashBuffer(const void *buf, size_t len) int hashStr(const HashTable *table, StgWord w) { - return hashBuffer(key, strlen(key)); + return hashBuffer(table, key, strlen(key)); } STATIC_INLINE int ===================================== rts/Hash.h ===================================== @@ -71,7 +71,7 @@ typedef int HashFunction(const HashTable *table, StgWord key); typedef int CompareFunction(StgWord key1, StgWord key2); // Helper for implementing hash functions -int hashBuffer(const void *buf, size_t len); +int hashBuffer(const HashTable *table, const void *buf, size_t len); int hashWord(const HashTable *table, StgWord key); int hashStr(const HashTable *table, StgWord w); ===================================== rts/linker/PEi386.c ===================================== @@ -427,8 +427,53 @@ const int default_alignment = 8; the pointer as a redirect. Essentially it's a DATA DLL reference. */ const void* __rts_iob_func = (void*)&__acrt_iob_func; +/* + * Note [Avoiding repeated DLL loading] + * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + * As LoadLibraryEx tends to be expensive and addDLL_PEi386 is called on every + * DLL-imported symbol, we use a hash-set to keep track of which DLLs have + * already been loaded. This hash-set is keyed on the dll_name passed to + * addDLL_PEi386 and serves as a quick check to avoid repeated calls to + * LoadLibraryEx for the identical DLL. See #26009. + */ + +typedef struct { + HashTable *hash; +} LoadedDllSet; + +LoadedDllSet loaded_dll_set; + +void initLoadedDllSet(LoadedDllSet *set) { + set->hash = allocHashTable(); +} + +int hash_path(const HashTable *table, StgWord key) +{ + const pathchar *key = (pathchar*) w; + return hashBuffer(table, key, sizeof(pathchar) * wcslen(key)); +} + +int compare_path(StgWord key1, StgWord key2) +{ + return wscmp((pathchar*) key1, (pathchar*) key2); +} + +void addLoadedDll(LoadedDllSet *set, pathchar *dll_name) +{ + insertHashTable_(set->hash, (StgWord) dll_name, (void*) 1, hash_path); +} + +bool isDllLoaded(LoadedDllSet *set, pathchar *dll_name) +{ + void * result = lookupHashTable_(set->hash, (StgWord) dll_name, hash_path, compare_path); + return result != NULL; +} + + void initLinker_PEi386(void) { + initLoadedDllSet(&loaded_dll_set); + if (!ghciInsertSymbolTable(WSTR("(GHCi/Ld special symbols)"), symhash, "__image_base__", GetModuleHandleW (NULL), HS_BOOL_TRUE, @@ -802,6 +847,10 @@ addDLL_PEi386( pathchar *dll_name, HINSTANCE *loaded ) /* ------------------- Win32 DLL loader ------------------- */ IF_DEBUG(linker, debugBelch("addDLL; dll_name = `%" PATH_FMT "'\n", dll_name)); + if (isDllLoaded(loaded_dll_set, dll_name)) { + return NULL; + } + /* The file name has no suffix (yet) so that we can try both foo.dll and foo.drv @@ -840,6 +889,7 @@ addDLL_PEi386( pathchar *dll_name, HINSTANCE *loaded ) goto error; } + addLoadedDll(&loaded_dll_set, dll_name); addDLLHandle(buf, instance); if (loaded) { *loaded = instance; View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/295ed26f4989dbe47b34c1257016c8… -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/295ed26f4989dbe47b34c1257016c8… You're receiving this email because of your account on gitlab.haskell.org.

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[Git][ghc/ghc][wip/T26009] 6 commits: rts/linker: Improve efficiency of proddable blocks structure
by Ben Gamari (＠bgamari) 19 May '25

19 May '25

Ben Gamari pushed to branch wip/T26009 at Glasgow Haskell Compiler / GHC Commits: 89031e59 by Ben Gamari at 2025-05-19T13:15:37-04:00 rts/linker: Improve efficiency of proddable blocks structure Previously the linker's "proddable blocks" check relied on a simple linked list of spans. This resulted in extremely poor complexity while linking objects with lots of small sections (e.g. objects built with split sections). Rework the mechanism to instead use a simple interval set implemented via binary search. Fixes #26009. - - - - - 3b644180 by Ben Gamari at 2025-05-19T13:51:31-04:00 testsuite: Add simple functional test for ProddableBlockSet - - - - - 525894ab by Ben Gamari at 2025-05-19T14:29:33-04:00 rts/linker/PEi386: Drop check for LOAD_LIBRARY_SEARCH_*_DIRS The `LOAD_LIBRARY_SEARCH_USER_DIRS` and `LOAD_LIBRARY_SEARCH_DEFAULT_DIRS` were introduced in Windows Vista and have been available every since. As we no longer support Windows XP we can drop this check. Addresses #26009. - - - - - b5fc6607 by Ben Gamari at 2025-05-19T15:08:38-04:00 rts/linker/PEi386: Clean up code style - - - - - ff9b8733 by Ben Gamari at 2025-05-19T15:27:52-04:00 rts/Hash: Factor out hashBuffer This is a useful helper which can be used for non-strings as well. - - - - - 295ed26f by Ben Gamari at 2025-05-19T15:28:36-04:00 rts/linker/PEi386: Maintain set of loaded DLLs Addresses #26009. - - - - - 7 changed files: - rts/Hash.c - rts/Hash.h - rts/linker/PEi386.c - rts/linker/ProddableBlocks.c - rts/linker/ProddableBlocks.h - + testsuite/tests/rts/TestProddableBlockSet.c - testsuite/tests/rts/all.T Changes: ===================================== rts/Hash.c ===================================== @@ -94,7 +94,7 @@ hashWord(const HashTable *table, StgWord key) } int -hashStr(const HashTable *table, StgWord w) +hashBuffer(const void *buf, size_t len) { const char *key = (char*) w; #if WORD_SIZE_IN_BITS == 64 @@ -114,6 +114,12 @@ hashStr(const HashTable *table, StgWord w) return bucket; } +int +hashStr(const HashTable *table, StgWord w) +{ + return hashBuffer(key, strlen(key)); +} + STATIC_INLINE int compareWord(StgWord key1, StgWord key2) { ===================================== rts/Hash.h ===================================== @@ -69,6 +69,10 @@ void * removeStrHashTable ( StrHashTable *table, const char * key, */ typedef int HashFunction(const HashTable *table, StgWord key); typedef int CompareFunction(StgWord key1, StgWord key2); + +// Helper for implementing hash functions +int hashBuffer(const void *buf, size_t len); + int hashWord(const HashTable *table, StgWord key); int hashStr(const HashTable *table, StgWord w); void insertHashTable_ ( HashTable *table, StgWord key, @@ -79,6 +83,7 @@ void * removeHashTable_ ( HashTable *table, StgWord key, const void *data, HashFunction f, CompareFunction cmp ); + /* Freeing hash tables */ void freeHashTable ( HashTable *table, void (*freeDataFun)(void *) ); ===================================== rts/linker/PEi386.c ===================================== @@ -427,8 +427,53 @@ const int default_alignment = 8; the pointer as a redirect. Essentially it's a DATA DLL reference. */ const void* __rts_iob_func = (void*)&__acrt_iob_func; +/* + * Note [Avoiding repeated DLL loading] + * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + * As LoadLibraryEx tends to be expensive and addDLL_PEi386 is called on every + * DLL-imported symbol, we use a hash-set to keep track of which DLLs have + * already been loaded. This hash-set is keyed on the dll_name passed to + * addDLL_PEi386 and serves as a quick check to avoid repeated calls to + * LoadLibraryEx for the identical DLL. See #26009. + */ + +typedef struct { + HashTable *hash; +} LoadedDllSet; + +LoadedDllSet loaded_dll_set; + +void initLoadedDllSet(LoadedDllSet *set) { + set->hash = allocHashTable(); +} + +int hash_path(const HashTable *table, StgWord key) +{ + const pathchar *key = (pathchar*) w; + return hashBuffer(key, sizeof(pathchar) * wcslen(key)); +} + +int compare_path(StgWord key1, StgWord key2) +{ + return wscmp((pathchar*) key1, (pathchar*) key2); +} + +void addLoadedDll(LoadedDllSet *set, pathchar *dll_name) +{ + insertHashTable_(set->hash, (StgWord) dll_name, (void*) 1, hash_path); +} + +bool isDllLoaded(LoadedDllSet *set, pathchar *dll_name) +{ + void * result = lookupHashTable_(set->hash, (StgWord) dll_name, hash_path, compare_path); + return result != NULL; +} + + void initLinker_PEi386(void) { + initLoadedDllSet(&loaded_dll_set); + if (!ghciInsertSymbolTable(WSTR("(GHCi/Ld special symbols)"), symhash, "__image_base__", GetModuleHandleW (NULL), HS_BOOL_TRUE, @@ -440,10 +485,11 @@ void initLinker_PEi386(void) addDLLHandle(WSTR("*.exe"), GetModuleHandle(NULL)); #endif - /* Register the cleanup routine as an exit handler, this gives other exit handlers - a chance to run which may need linker information. Exit handlers are ran in - reverse registration order so this needs to be before the linker loads anything. */ - atexit (exitLinker_PEi386); + /* Register the cleanup routine as an exit handler, this gives other exit handlers + * a chance to run which may need linker information. Exit handlers are ran in + * reverse registration order so this needs to be before the linker loads anything. + */ + atexit (exitLinker_PEi386); } void exitLinker_PEi386(void) @@ -798,12 +844,12 @@ uint8_t* getSymShortName ( COFF_HEADER_INFO *info, COFF_symbol* sym ) const char * addDLL_PEi386( pathchar *dll_name, HINSTANCE *loaded ) { - /* ------------------- Win32 DLL loader ------------------- */ - - pathchar* buf; - HINSTANCE instance; + /* ------------------- Win32 DLL loader ------------------- */ + IF_DEBUG(linker, debugBelch("addDLL; dll_name = `%" PATH_FMT "'\n", dll_name)); - IF_DEBUG(linker, debugBelch("addDLL; dll_name = `%" PATH_FMT "'\n", dll_name)); + if (isDllLoaded(loaded_dll_set)) { + return NULL; + } /* The file name has no suffix (yet) so that we can try both foo.dll and foo.drv @@ -816,35 +862,23 @@ addDLL_PEi386( pathchar *dll_name, HINSTANCE *loaded ) extension. */ size_t bufsize = pathlen(dll_name) + 10; - buf = stgMallocBytes(bufsize * sizeof(wchar_t), "addDLL"); + pathchar *buf = stgMallocBytes(bufsize * sizeof(wchar_t), "addDLL"); /* These are ordered by probability of success and order we'd like them. */ const wchar_t *formats[] = { L"%ls.DLL", L"%ls.DRV", L"lib%ls.DLL", L"%ls" }; const DWORD flags[] = { LOAD_LIBRARY_SEARCH_USER_DIRS | LOAD_LIBRARY_SEARCH_DEFAULT_DIRS, 0 }; - int cFormat, cFlag; - int flags_start = 1; /* Assume we don't support the new API. */ - - /* Detect if newer API are available, if not, skip the first flags entry. */ - if (GetProcAddress((HMODULE)LoadLibraryW(L"Kernel32.DLL"), "AddDllDirectory")) { - flags_start = 0; - } - /* Iterate through the possible flags and formats. */ - for (cFlag = flags_start; cFlag < 2; cFlag++) - { - for (cFormat = 0; cFormat < 4; cFormat++) - { + HINSTANCE instance; + for (int cFlag = 0; cFlag < 2; cFlag++) { + for (int cFormat = 0; cFormat < 4; cFormat++) { snwprintf(buf, bufsize, formats[cFormat], dll_name); instance = LoadLibraryExW(buf, NULL, flags[cFlag]); if (instance == NULL) { - if (GetLastError() != ERROR_MOD_NOT_FOUND) - { + if (GetLastError() != ERROR_MOD_NOT_FOUND) { goto error; } - } - else - { + } else { break; /* We're done. DLL has been loaded. */ } } @@ -855,6 +889,7 @@ addDLL_PEi386( pathchar *dll_name, HINSTANCE *loaded ) goto error; } + addLoadedDll(&loaded_dll_set, dll_name); addDLLHandle(buf, instance); if (loaded) { *loaded = instance; ===================================== rts/linker/ProddableBlocks.c ===================================== @@ -6,65 +6,125 @@ * * ---------------------------------------------------------------------------*/ + +/* + * Sanity checking. For each ObjectCode, maintain a list of address ranges + * which may be prodded during relocation, and abort if we try and write + * outside any of these. + */ + #include "Rts.h" #include "RtsUtils.h" #include "linker/ProddableBlocks.h" -struct _ProddableBlock { - void* start; - int size; - struct _ProddableBlock* next; -}; +#include <stdlib.h> +#include <string.h> -typedef struct _ProddableBlock ProddableBlock; +typedef struct _ProddableBlock { + uintptr_t start; // inclusive + uintptr_t end; // inclusive +} ProddableBlock; void initProddableBlockSet ( ProddableBlockSet* set ) { - set->head = NULL; + set->data = NULL; + set->capacity = 0; + set->size = 0; } -/* ----------------------------------------------------------------------------- - * Sanity checking. For each ObjectCode, maintain a list of address ranges - * which may be prodded during relocation, and abort if we try and write - * outside any of these. - */ void -addProddableBlock ( ProddableBlockSet* set, void* start, int size ) +freeProddableBlocks (ProddableBlockSet *set) +{ + stgFree(set->data); + set->data = NULL; + set->size = 0; + set->capacity = 0; +} + +// Binary search for the first interval with start >= value. Returns index or +// size if none. +static size_t +findLower(const ProddableBlockSet *set, uintptr_t value) { - ProddableBlock* pb = stgMallocBytes(sizeof(ProddableBlock), "addProddableBlock"); - - IF_DEBUG(linker, debugBelch("addProddableBlock: %p %d\n", start, size)); - ASSERT(size > 0); - pb->start = start; - pb->size = size; - pb->next = set->head; - set->head = pb; + size_t l = 0; + size_t r = set->size; + while (l < r) { + size_t mid = l + (r - l) / 2; + if (set->data[mid].start < value) { + l = mid + 1; + } else { + r = mid; + } + } + return l; +} + +// Check whether a given value is a member of the set. +bool +containsSpan ( const ProddableBlockSet *set, uintptr_t start, uintptr_t end ) +{ + size_t i = findLower(set, start+1); + return i > 0 + && set->data[i-1].start <= start + && end <= set->data[i-1].end; } void -checkProddableBlock (ProddableBlockSet *set, void *addr, size_t size ) +checkProddableBlock (const ProddableBlockSet *set, void *addr, size_t size ) { - ProddableBlock* pb; - - for (pb = set->head; pb != NULL; pb = pb->next) { - char* s = (char*)(pb->start); - char* e = s + pb->size; - char* a = (char*)addr; - if (a >= s && (a+size) <= e) - return; + if (! containsSpan(set, (uintptr_t) addr, (uintptr_t) addr+size)) { + barf("checkProddableBlock: invalid fixup in runtime linker: %p", addr); } - barf("checkProddableBlock: invalid fixup in runtime linker: %p", addr); } -void freeProddableBlocks (ProddableBlockSet *set) +// Ensure capacity for at least new_capacity intervals +static void +ensureCapacity(ProddableBlockSet *set, size_t new_capacity) { + if (new_capacity > set->capacity) { + size_t cap = set->capacity ? set->capacity * 2 : 4; + if (cap < new_capacity) { + cap = new_capacity; + } + ProddableBlock *tmp = stgReallocBytes(set->data, cap * sizeof(ProddableBlock), "addProddableBlock"); + set->data = tmp; + set->capacity = cap; + } +} + +void +addProddableBlock ( ProddableBlockSet* set, void* start_ptr, size_t size ) { - ProddableBlock *pb, *next; + const uintptr_t start = (uintptr_t) start_ptr; + const uintptr_t end = (uintptr_t) start + size; + size_t i = findLower(set, start); + + // check previous interval if it is overlapping or adjacent + if (i > 0 && start <= set->data[i-1].end + 1) { + // merge with left interval + i--; + if (end > set->data[i].end) { + set->data[i].end = end; + } + } else { + // insert new interval + ensureCapacity(set, set->size + 1); + memmove(&set->data[i+1], &set->data[i], sizeof(ProddableBlock) * (set->size - i)); + set->data[i].start = start; + set->data[i].end = end; + set->size++; + } + + // coalesce overlaps on right + size_t j = i; + while (j < set->size && set->data[j].start <= set->data[i].end + 1) { + set->data[i].end = set->data[j].end; + j++; + } - for (pb = set->head; pb != NULL; pb = next) { - next = pb->next; - stgFree(pb); + if (j != i) { + memmove(&set->data[i+1], &set->data[j], sizeof(ProddableBlock) * (set->size - j)); + set->size -= j - i - 1; } - set->head = NULL; } ===================================== rts/linker/ProddableBlocks.h ===================================== @@ -8,20 +8,31 @@ #pragma once +#include <stdbool.h> +#include <stddef.h> +#include <stdint.h> + // An interval set on uintptr_t. struct _ProddableBlock; typedef struct { - struct _ProddableBlock *head; + size_t size; + size_t capacity; + // sorted list of disjoint (start,end) pairs + struct _ProddableBlock *data; } ProddableBlockSet; void initProddableBlockSet ( ProddableBlockSet* set ); // Insert an interval. -void addProddableBlock ( ProddableBlockSet* set, void* start, int size ); +void addProddableBlock ( ProddableBlockSet* set, void* start, size_t size ); // Check that an address belongs to the set. -void checkProddableBlock (ProddableBlockSet *set, void *addr, size_t size ); +void checkProddableBlock (const ProddableBlockSet *set, void *addr, size_t size ); + // Free a set. void freeProddableBlocks (ProddableBlockSet *set); + +// For testing. +bool containsSpan ( const ProddableBlockSet *set, uintptr_t start, uintptr_t end ); ===================================== testsuite/tests/rts/TestProddableBlockSet.c ===================================== @@ -0,0 +1,33 @@ +#include <assert.h> +#include <stdbool.h> +#include <stdint.h> +#include <stddef.h> + +// Excerpted from ProddableBlocks.h +typedef struct { + size_t size; + size_t capacity; + // sorted list of disjoint (start,end) pairs + struct _ProddableBlock *data; +} ProddableBlockSet; + +void initProddableBlockSet ( ProddableBlockSet* set ); +void addProddableBlock ( ProddableBlockSet* set, void* start, size_t size ); +bool containsSpan ( const ProddableBlockSet *set, uintptr_t start, uintptr_t end ); + +int main () { + ProddableBlockSet set; + initProddableBlockSet(&set); + addProddableBlock(&set, (void*) 0x20, 0x10); + addProddableBlock(&set, (void*) 0x30, 0x10); + addProddableBlock(&set, (void*) 0x100, 0x10); + + assert( containsSpan(&set, 0x20, 0x30)); + assert( containsSpan(&set, 0x30, 0x29)); + assert(!containsSpan(&set, 0x30, 0x49)); + assert(!containsSpan(&set, 0x60, 0x70)); + assert(!containsSpan(&set, 0x90, 0x110)); + assert( containsSpan(&set, 0x100, 0x101)); + return 0; +} + ===================================== testsuite/tests/rts/all.T ===================================== @@ -641,3 +641,5 @@ test('T25280', [unless(opsys('linux'),skip),req_process,js_skip], compile_and_ru # N.B. This will likely issue a warning on stderr but we merely care that the # program doesn't crash. test('T25560', [req_c_rts, ignore_stderr], compile_and_run, ['']) + +test('TestProddableBlockSet', [req_c_rts], multimod_compile_and_run, ['TestProddableBlockSet.c', '-no-hs-main']) View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/998c2117b4429624fd33e5e58548b8… -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/998c2117b4429624fd33e5e58548b8… You're receiving this email because of your account on gitlab.haskell.org.

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[Git][ghc/ghc][wip/T26003] Track rewriter sets more accurately in constraint solving
by sheaf (＠sheaf) 19 May '25

19 May '25

sheaf pushed to branch wip/T26003 at Glasgow Haskell Compiler / GHC Commits: 98ab1713 by Simon Peyton Jones at 2025-05-19T21:12:55+02:00 Track rewriter sets more accurately in constraint solving This MR addresses #26003, by refactoring the arcane intricacies of Note [Equalities with incompatible kinds]. NB: now retitled to Note [Equalities with heterogeneous kinds]. and the main Note for this MR. In particular: * Abandon invariant (COERCION-HOLE) in Note [Unification preconditions] in GHC.Tc.Utils.Unify. * Abandon invariant (TyEq:CH)) in Note [Canonical equalities] in GHC.Tc.Types.Constraint. * Instead: add invariant (REWRITERS) to Note [Unification preconditions]: unify only if the constraint has an empty rewriter set. Implementation: * In canEqCanLHSFinish_try_unification, skip trying unification if there is a non-empty rewriter set. * To do this, make sure the rewriter set is zonked; do so in selectNextWorkItem, which also deals with prioritisation. * When a coercion hole is filled, kick out inert equalities that have that hole as a rewriter. It might now be unlocked and available to unify. * Remove the ad-hoc `ch_hetero_kind` field of `CoercionHole`. * In `selectNextWorkItem`, priorities equalities withan empty rewriter set. * Defaulting: see (DE6) in Note [Defaulting equalities] and Note [Limited defaulting in the ambiguity check] * Concreteness checks: there is some extra faff to try to get decent error messages when the FRR (representation-polymorphism) checks fail. In partiular, add a "When unifying..." explanation when the representation-polymorphism check arose from another constraint. - - - - - 65 changed files: - compiler/GHC/Core/Coercion.hs - compiler/GHC/Core/Predicate.hs - compiler/GHC/Core/TyCo/Rep.hs - compiler/GHC/Core/TyCo/Tidy.hs - compiler/GHC/Tc/Errors.hs - compiler/GHC/Tc/Errors/Ppr.hs - compiler/GHC/Tc/Errors/Types.hs - compiler/GHC/Tc/Gen/HsType.hs - compiler/GHC/Tc/Plugin.hs - compiler/GHC/Tc/Solver.hs - compiler/GHC/Tc/Solver/Default.hs - compiler/GHC/Tc/Solver/Equality.hs - compiler/GHC/Tc/Solver/InertSet.hs - compiler/GHC/Tc/Solver/Monad.hs - compiler/GHC/Tc/Types/Constraint.hs - compiler/GHC/Tc/Utils/TcMType.hs - compiler/GHC/Tc/Utils/Unify.hs - compiler/GHC/Tc/Zonk/TcType.hs - compiler/GHC/Types/Error/Codes.hs - testsuite/tests/dependent/should_fail/T11471.stderr - testsuite/tests/diagnostic-codes/codes.stdout - testsuite/tests/indexed-types/should_fail/T8227.stderr - testsuite/tests/indexed-types/should_fail/T9662.stderr - testsuite/tests/partial-sigs/should_fail/T14040a.stderr - testsuite/tests/partial-sigs/should_fail/T14584.stderr - testsuite/tests/polykinds/T14172.stderr - testsuite/tests/polykinds/T14846.stderr - testsuite/tests/rep-poly/RepPolyArgument.stderr - testsuite/tests/rep-poly/RepPolyBackpack1.stderr - testsuite/tests/rep-poly/RepPolyBinder.stderr - testsuite/tests/rep-poly/RepPolyDoBind.stderr - testsuite/tests/rep-poly/RepPolyDoBody1.stderr - testsuite/tests/rep-poly/RepPolyDoBody2.stderr - testsuite/tests/rep-poly/RepPolyLeftSection2.stderr - testsuite/tests/rep-poly/RepPolyMagic.stderr - testsuite/tests/rep-poly/RepPolyMcBind.stderr - testsuite/tests/rep-poly/RepPolyMcBody.stderr - testsuite/tests/rep-poly/RepPolyMcGuard.stderr - testsuite/tests/rep-poly/RepPolyNPlusK.stderr - testsuite/tests/rep-poly/RepPolyPatBind.stderr - testsuite/tests/rep-poly/RepPolyRecordUpdate.stderr - testsuite/tests/rep-poly/RepPolyRightSection.stderr - testsuite/tests/rep-poly/RepPolyRule1.stderr - testsuite/tests/rep-poly/RepPolyTuple.stderr - testsuite/tests/rep-poly/RepPolyTuple4.stderr - testsuite/tests/rep-poly/RepPolyTupleSection.stderr - testsuite/tests/rep-poly/RepPolyWrappedVar.stderr - testsuite/tests/rep-poly/T11473.stderr - testsuite/tests/rep-poly/T12709.stderr - testsuite/tests/rep-poly/T12973.stderr - testsuite/tests/rep-poly/T13233.stderr - testsuite/tests/rep-poly/T13929.stderr - testsuite/tests/rep-poly/T14561.stderr - testsuite/tests/rep-poly/T14561b.stderr - testsuite/tests/rep-poly/T17817.stderr - testsuite/tests/rep-poly/T19615.stderr - testsuite/tests/rep-poly/T19709b.stderr - testsuite/tests/rep-poly/T21906.stderr - testsuite/tests/rep-poly/T23903.stderr - testsuite/tests/rep-poly/UnliftedNewtypesCoerceFail.stderr - testsuite/tests/typecheck/no_skolem_info/T14040.stderr - testsuite/tests/typecheck/should_compile/T25266a.stderr - testsuite/tests/typecheck/should_fail/T16204c.stderr - testsuite/tests/typecheck/should_fail/T7696.stderr - testsuite/tests/typecheck/should_fail/T8603.stderr The diff was not included because it is too large. View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/98ab1713090430cd3740463d2bcfb6e… -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/98ab1713090430cd3740463d2bcfb6e… You're receiving this email because of your account on gitlab.haskell.org.

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[Git][ghc/ghc] Pushed new branch wip/clear-memory-0xaa
by Cheng Shao (＠TerrorJack) 19 May '25

19 May '25

Cheng Shao pushed new branch wip/clear-memory-0xaa at Glasgow Haskell Compiler / GHC -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/tree/wip/clear-memory-0xaa You're receiving this email because of your account on gitlab.haskell.org.

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[Git][ghc/ghc][wip/int-index/data-namespace-specifier] 11 commits: Refine `noGivenNewtypeReprEqs` to account for quantified constraints
by Vladislav Zavialov (＠int-index) 19 May '25

19 May '25

Vladislav Zavialov pushed to branch wip/int-index/data-namespace-specifier at Glasgow Haskell Compiler / GHC Commits: 7b2d1e6d by Simon Peyton Jones at 2025-05-11T03:24:47-04:00 Refine `noGivenNewtypeReprEqs` to account for quantified constraints This little MR fixes #26020. We are on the edge of completeness for newtype equalities (that doesn't change) but this MR makes GHC a bit more consistent -- and fixes the bug reported. - - - - - eaa8093b by Cheng Shao at 2025-05-11T03:25:28-04:00 wasm: mark freeJSVal as INLINE This patch marks `freeJSVal` as `INLINE` for the wasm backend. I noticed that the `freeJSVal` invocations are not inlined when inspecting STG/Cmm dumps of downstream libraries that use release build of the wasm backend. The performance benefit of inlining here is very modest, but so is the cost anyway; if you are using `freeJSVal` at all then you care about every potential chance to improve performance :) - - - - - eac196df by Cheng Shao at 2025-05-11T03:25:28-04:00 wasm: add zero length fast path for fromJSString This patch adds a zero length fast path for `fromJSString`; when marshaling a zero-length `JSString` we don't need to allocate an empty `ByteArray#` at all. - - - - - 652cba7e by Peng Fan at 2025-05-14T04:24:35-04:00 Add LoongArch NCG support Not supported before. - - - - - c01f4374 by Lin Runze at 2025-05-14T04:24:35-04:00 ci: Add LoongArch64 cross-compile CI for testing - - - - - ce6cf240 by Ben Gamari at 2025-05-14T04:25:18-04:00 rts/linker: Don't fail due to RTLD_NOW In !12264 we started using the NativeObj machinery introduced some time ago for loading of shared objects. One of the side-effects of this change is shared objects are now loaded eagerly (i.e. with `RTLD_NOW`). This is needed by NativeObj to ensure full visibility of the mappings of the loaded object, which is in turn needed for safe shared object unloading. Unfortunately, this change subtly regressed, causing compilation failures in some programs. Specifically, shared objects which refer to undefined symbols (e.g. which may be usually provided by either the executable image or libraries loaded via `dlopen`) will fail to load with eager binding. This is problematic as GHC loads all package dependencies while, e.g., evaluating TemplateHaskell splices. This results in compilation failures in programs depending upon (but not using at compile-time) packages with undefined symbol references. To mitigate this NativeObj now first attempts to load an object via eager binding, reverting to lazy binding (and disabling unloading) on failure. See Note [Don't fail due to RTLD_NOW]. Fixes #25943. - - - - - 88ee8bb5 by Sylvain Henry at 2025-05-14T04:26:15-04:00 Deprecate GHC.JS.Prim.Internal.Build (#23432) Deprecated as per CLC proposal 329 (https://github.com/haskell/core-libraries-committee/issues/329) - - - - - b4ed465b by Cheng Shao at 2025-05-14T04:26:57-04:00 libffi: update to 3.4.8 Bumps libffi submodule. - - - - - a3e71296 by Matthew Pickering at 2025-05-14T04:27:38-04:00 Remove leftover trace - - - - - 2d0ecdc6 by Cheng Shao at 2025-05-14T04:28:19-04:00 Revert "ci: re-enable chrome for wasm ghci browser tests" This reverts commit fee9b351fa5a35d5778d1252789eacaaf5663ae8. Unfortunately the chrome test jobs may still timeout on certain runners (e.g. OpenCape) for unknown reasons. - - - - - e2d7185f by Vladislav Zavialov at 2025-05-19T19:56:07+03:00 Allow the 'data' keyword in import/export lists (#25899) This patch introduces the 'data' namespace specifier in import and export lists. The intended use is to import data constructors without their parent type constructors, e.g. import Data.Proxy as D (data Proxy) type DP = D.Proxy -- promoted data constructor Additionally, it is possible to use 'data' to explicitly qualify any data constructors or terms, incl. operators and field selectors import Prelude (Semigroup(data (<>))) import Data.Function (data (&)) import Data.Monoid (data Dual, data getDual) x = Dual "Hello" <> Dual "World" & getDual The implementation mostly builds on top of the existing logic for the 'type' and 'pattern' namespace specifiers, plus there are a few tweaks to how we generate suggestions in error messages. - - - - - 81 changed files: - .gitlab/generate-ci/gen_ci.hs - .gitlab/jobs.yaml - compiler/CodeGen.Platform.h - compiler/GHC/Cmm/CLabel.hs - compiler/GHC/CmmToAsm.hs - compiler/GHC/CmmToAsm/Dwarf/Constants.hs - + compiler/GHC/CmmToAsm/LA64.hs - + compiler/GHC/CmmToAsm/LA64/CodeGen.hs - + compiler/GHC/CmmToAsm/LA64/Cond.hs - + compiler/GHC/CmmToAsm/LA64/Instr.hs - + compiler/GHC/CmmToAsm/LA64/Ppr.hs - + compiler/GHC/CmmToAsm/LA64/RegInfo.hs - + compiler/GHC/CmmToAsm/LA64/Regs.hs - compiler/GHC/CmmToAsm/PIC.hs - compiler/GHC/CmmToAsm/Reg/Graph/TrivColorable.hs - compiler/GHC/CmmToAsm/Reg/Linear.hs - compiler/GHC/CmmToAsm/Reg/Linear/FreeRegs.hs - + compiler/GHC/CmmToAsm/Reg/Linear/LA64.hs - compiler/GHC/CmmToAsm/Reg/Target.hs - compiler/GHC/Driver/Backend.hs - compiler/GHC/Driver/DynFlags.hs - compiler/GHC/Hs/ImpExp.hs - compiler/GHC/Iface/Ext/Ast.hs - compiler/GHC/Parser.y - compiler/GHC/Parser/PostProcess.hs - compiler/GHC/Platform/LoongArch64.hs → compiler/GHC/Platform/LA64.hs - compiler/GHC/Platform/Regs.hs - compiler/GHC/Rename/Names.hs - compiler/GHC/Tc/Errors/Ppr.hs - compiler/GHC/Tc/Errors/Types.hs - compiler/GHC/Tc/Gen/Export.hs - compiler/GHC/Tc/Solver/Equality.hs - compiler/GHC/Tc/Solver/InertSet.hs - compiler/GHC/Types/Error/Codes.hs - compiler/GHC/Types/Hint.hs - compiler/GHC/Types/Hint/Ppr.hs - compiler/GHC/Unit/Module/Graph.hs - compiler/Language/Haskell/Syntax/Extension.hs - compiler/Language/Haskell/Syntax/ImpExp.hs - compiler/ghc.cabal.in - docs/users_guide/9.14.1-notes.rst - docs/users_guide/exts/explicit_namespaces.rst - docs/users_guide/exts/pattern_synonyms.rst - hadrian/bindist/config.mk.in - hadrian/src/Oracles/Setting.hs - hadrian/src/Settings/Builders/RunTest.hs - libffi-tarballs - libraries/base/changelog.md - libraries/base/src/GHC/JS/Prim/Internal/Build.hs - libraries/ghc-internal/src/GHC/Internal/Wasm/Prim/Types.hs - rts/linker/LoadNativeObjPosix.c - testsuite/tests/module/T21826.stderr - testsuite/tests/rename/should_compile/T22581d.stdout - + testsuite/tests/rename/should_compile/T25899a.hs - + testsuite/tests/rename/should_compile/T25899b.hs - + testsuite/tests/rename/should_compile/T25899c.hs - + testsuite/tests/rename/should_compile/T25899c_helper.hs - + testsuite/tests/rename/should_compile/T25899d.script - + testsuite/tests/rename/should_compile/T25899d.stdout - testsuite/tests/rename/should_compile/all.T - testsuite/tests/rename/should_fail/T22581a.stderr - testsuite/tests/rename/should_fail/T22581b.stderr - + testsuite/tests/rename/should_fail/T25899e1.hs - + testsuite/tests/rename/should_fail/T25899e1.stderr - + testsuite/tests/rename/should_fail/T25899e2.hs - + testsuite/tests/rename/should_fail/T25899e2.stderr - + testsuite/tests/rename/should_fail/T25899e3.hs - + testsuite/tests/rename/should_fail/T25899e3.stderr - + testsuite/tests/rename/should_fail/T25899e_helper.hs - + testsuite/tests/rename/should_fail/T25899f.hs - + testsuite/tests/rename/should_fail/T25899f.stderr - + testsuite/tests/rename/should_fail/T25899f_helper.hs - testsuite/tests/rename/should_fail/all.T - testsuite/tests/rts/all.T - + testsuite/tests/typecheck/should_compile/T26020.hs - + testsuite/tests/typecheck/should_compile/T26020a.hs - + testsuite/tests/typecheck/should_compile/T26020a_help.hs - testsuite/tests/typecheck/should_compile/all.T - utils/check-exact/ExactPrint.hs - utils/ghc-toolchain/exe/Main.hs - utils/ghc-toolchain/src/GHC/Toolchain/Tools/Cc.hs The diff was not included because it is too large. View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/bbd4f1e2608fa0f4ffb3dad45e863f… -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/bbd4f1e2608fa0f4ffb3dad45e863f… You're receiving this email because of your account on gitlab.haskell.org.

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[Git][ghc/ghc][wip/improve-implicit-lifting-error] Refactor the treatment of nested Template Haskell splices
by Matthew Pickering (＠mpickering) 19 May '25

19 May '25

Matthew Pickering pushed to branch wip/improve-implicit-lifting-error at Glasgow Haskell Compiler / GHC Commits: b82b507e by Matthew Pickering at 2025-05-19T18:14:52+01:00 Refactor the treatment of nested Template Haskell splices * The difference between a normal splice, a quasiquoter and implicit splice caused by lifting is stored in the AST after renaming. * Information that the renamer learns about splices is stored in the relevant splice extension points (XUntypedSpliceExpr, XQuasiQuote). * Normal splices and quasi quotes record the flavour of splice (exp/pat/dec etc) * Implicit lifting stores information about why the lift was attempted, so if it fails, that can be reported to the user. * After renaming, the decision taken to attempt to implicitly lift a variable is stored in the `XXUntypedSplice` extension field in the `HsImplicitLiftSplice` constructor. * Since all the information is stored in the AST, in `HsUntypedSplice`, the type of `PendingRnSplice` now just stores a `HsUntypedSplice`. * Error messages since the original program can be easily printed, this is noticeable in the case of implicit lifting. * The user-written syntax is directly type-checked. Before, some desugaring took place in the * Fixes .hie files to work better with nested splices (nested splices are not indexed) * The location of the quoter in a quasiquote is now located, so error messages will precisely point to it (and again, it is indexed by hie files) In the future, the typechecked AST should also retain information about the splices and the specific desugaring being left to the desugarer. Also, `runRnSplice` should call `tcUntypedSplice`, otherwise the typechecking logic is duplicated (see the `QQError` and `QQTopError` tests for a difference caused by this). - - - - - 43 changed files: - compiler/GHC/Builtin/Names/TH.hs - compiler/GHC/Hs/Expr.hs - compiler/GHC/Hs/Expr.hs-boot - compiler/GHC/Hs/Instances.hs - compiler/GHC/HsToCore/Quote.hs - compiler/GHC/Iface/Ext/Ast.hs - compiler/GHC/Parser.y - compiler/GHC/Parser/Lexer.x - compiler/GHC/Rename/Expr.hs - compiler/GHC/Rename/Splice.hs - compiler/GHC/Tc/Errors/Ppr.hs - compiler/GHC/Tc/Gen/App.hs - compiler/GHC/Tc/Gen/Expr.hs - compiler/GHC/Tc/Gen/Head.hs - compiler/GHC/Tc/Gen/Splice.hs - compiler/GHC/Tc/Gen/Splice.hs-boot - compiler/GHC/Tc/Types/ErrCtxt.hs - compiler/GHC/Tc/Types/TH.hs - compiler/GHC/Tc/Utils/Concrete.hs - compiler/GHC/Tc/Utils/TcMType.hs - compiler/GHC/ThToHs.hs - compiler/Language/Haskell/Syntax/Expr.hs - compiler/Language/Haskell/Syntax/Extension.hs - testsuite/tests/linters/notes.stdout - testsuite/tests/quotes/LiftErrMsg.stderr - testsuite/tests/quotes/LiftErrMsgDefer.stderr - + testsuite/tests/quotes/LiftErrMsgTyped.hs - + testsuite/tests/quotes/LiftErrMsgTyped.stderr - + testsuite/tests/quotes/QQError.hs - + testsuite/tests/quotes/QQError.stderr - testsuite/tests/quotes/T10384.stderr - testsuite/tests/quotes/TH_localname.stderr - testsuite/tests/quotes/all.T - + testsuite/tests/th/QQInQuote.hs - + testsuite/tests/th/QQTopError.hs - + testsuite/tests/th/QQTopError.stderr - testsuite/tests/th/T10598_TH.stderr - testsuite/tests/th/T14681.stderr - testsuite/tests/th/T17804.stderr - testsuite/tests/th/T5508.stderr - testsuite/tests/th/TH_Lift.stderr - testsuite/tests/th/all.T - testsuite/tests/th/overloaded/TH_overloaded_constraints_fail.stderr The diff was not included because it is too large. View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/b82b507ee0eef779acb1385d71a6300… -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/b82b507ee0eef779acb1385d71a6300… 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] 2 commits: compiler: Use field selectors when creating BCOs
by Marge Bot (＠marge-bot) 19 May '25

19 May '25

Marge Bot pushed to branch wip/marge_bot_batch_merge_job at Glasgow Haskell Compiler / GHC Commits: 944b4a78 by Ben Gamari at 2025-05-19T13:09:35-04:00 compiler: Use field selectors when creating BCOs This makes it easier to grep for these fields. - - - - - 777ff2e9 by Ben Gamari at 2025-05-19T13:09:35-04:00 compiler: Clarify BCO size Previously the semantics and size of StgBCO was a bit unclear. Specifically, the `size` field was documented to contain the size of the bitmap whereas it was actually the size of the closure *and* bitmap. Additionally, it was not as clear as it could be that the bitmap was a full StgLargeBitmap with its own `size` field. - - - - - 4 changed files: - compiler/GHC/ByteCode/Asm.hs - compiler/GHC/ByteCode/Linker.hs - rts/PrimOps.cmm - rts/include/rts/storage/Closures.h Changes: ===================================== compiler/GHC/ByteCode/Asm.hs ===================================== @@ -266,7 +266,13 @@ assembleBCO platform let !insns_arr = mkBCOByteArray $ final_isn_array !bitmap_arr = mkBCOByteArray $ mkBitmapArray bsize bitmap - ul_bco = UnlinkedBCO nm arity insns_arr bitmap_arr (fromSmallArray final_lit_array) (fromSmallArray final_ptr_array) + ul_bco = UnlinkedBCO { unlinkedBCOName = nm + , unlinkedBCOArity = arity + , unlinkedBCOInstrs = insns_arr + , unlinkedBCOBitmap = bitmap_arr + , unlinkedBCOLits = fromSmallArray final_lit_array + , unlinkedBCOPtrs = fromSmallArray final_ptr_array + } -- 8 Aug 01: Finalisers aren't safe when attached to non-primitive -- objects, since they might get run too early. Disable this until @@ -275,6 +281,7 @@ assembleBCO platform return ul_bco +-- | Construct a word-array containing an @StgLargeBitmap@. mkBitmapArray :: Word -> [StgWord] -> UArray Int Word -- Here the return type must be an array of Words, not StgWords, -- because the underlying ByteArray# will end up as a component ===================================== compiler/GHC/ByteCode/Linker.hs ===================================== @@ -65,11 +65,13 @@ linkBCO interp pkgs_loaded le bco_ix (lits :: [Word]) <- mapM (fmap fromIntegral . lookupLiteral interp pkgs_loaded le) (elemsFlatBag lits0) ptrs <- mapM (resolvePtr interp pkgs_loaded le bco_ix) (elemsFlatBag ptrs0) let lits' = listArray (0 :: Int, fromIntegral (sizeFlatBag lits0)-1) lits - return (ResolvedBCO isLittleEndian arity - insns - bitmap - (mkBCOByteArray lits') - (addListToSS emptySS ptrs)) + return $ ResolvedBCO { resolvedBCOIsLE = isLittleEndian + , resolvedBCOArity = arity + , resolvedBCOInstrs = insns + , resolvedBCOBitmap = bitmap + , resolvedBCOLits = mkBCOByteArray lits' + , resolvedBCOPtrs = addListToSS emptySS ptrs + } lookupLiteral :: Interp -> PkgsLoaded -> LinkerEnv -> BCONPtr -> IO Word lookupLiteral interp pkgs_loaded le ptr = case ptr of ===================================== rts/PrimOps.cmm ===================================== @@ -2440,6 +2440,7 @@ stg_newBCOzh ( P_ instrs, W_ arity, P_ bitmap_arr ) { + // N.B. bitmap_arr contains a full StgLargeBitmap object. W_ bco, bytes, words; words = BYTES_TO_WDS(SIZEOF_StgBCO) + BYTE_ARR_WDS(bitmap_arr); ===================================== rts/include/rts/storage/Closures.h ===================================== @@ -427,7 +427,7 @@ typedef struct { StgArrBytes *literals; // literals used by the instructions StgMutArrPtrs *ptrs; // free variables StgHalfWord arity; // arity of this BCO - StgHalfWord size; // size of the bitmap + StgHalfWord size; // size of the closure and bitmap StgWord bitmap[]; // an StgLargeBitmap } StgBCO; View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/0ecc302d2c15b517d9aa2f5df868c7… -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/0ecc302d2c15b517d9aa2f5df868c7… You're receiving this email because of your account on gitlab.haskell.org.

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[Git][ghc/ghc] Pushed new branch wip/T26009
by Ben Gamari (＠bgamari) 19 May '25

19 May '25

Ben Gamari pushed new branch wip/T26009 at Glasgow Haskell Compiler / GHC -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/tree/wip/T26009 You're receiving this email because of your account on gitlab.haskell.org.

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[Git][ghc/ghc][wip/T25989] 2 commits: rts/linker: Factor out ProddableBlocks machinery
by Ben Gamari (＠bgamari) 19 May '25

19 May '25

Ben Gamari pushed to branch wip/T25989 at Glasgow Haskell Compiler / GHC Commits: f4996065 by Ben Gamari at 2025-05-17T14:28:55-04:00 rts/linker: Factor out ProddableBlocks machinery - - - - - 88dc662f by Ben Gamari at 2025-05-19T12:30:34-04:00 rts/linker: Improve efficiency of proddable blocks structure Previously the linker's "proddable blocks" check relied on a simple linked list of spans. This resulted in extremely poor complexity while linking objects with lots of small sections (e.g. objects built with split sections). Rework the mechanism to instead use a simple interval set implemented via binary search. Fixes #26009. - - - - - 8 changed files: - rts/Linker.c - rts/LinkerInternals.h - rts/linker/Elf.c - rts/linker/MachO.c - rts/linker/PEi386.c - + rts/linker/ProddableBlocks.c - + rts/linker/ProddableBlocks.h - rts/rts.cabal Changes: ===================================== rts/Linker.c ===================================== @@ -1194,7 +1194,7 @@ void freeObjectCode (ObjectCode *oc) stgFree(oc->sections); } - freeProddableBlocks(oc); + freeProddableBlocks(&oc->proddables); freeSegments(oc); /* Free symbol_extras. On x86_64 Windows, symbol_extras are allocated @@ -1279,7 +1279,7 @@ mkOc( ObjectType type, pathchar *path, char *image, int imageSize, oc->sections = NULL; oc->n_segments = 0; oc->segments = NULL; - oc->proddables = NULL; + initProddableBlockSet(&oc->proddables); oc->foreign_exports = NULL; #if defined(NEED_SYMBOL_EXTRAS) oc->symbol_extras = NULL; @@ -1834,50 +1834,6 @@ OStatus getObjectLoadStatus (pathchar *path) return r; } -/* ----------------------------------------------------------------------------- - * Sanity checking. For each ObjectCode, maintain a list of address ranges - * which may be prodded during relocation, and abort if we try and write - * outside any of these. - */ -void -addProddableBlock ( ObjectCode* oc, void* start, int size ) -{ - ProddableBlock* pb - = stgMallocBytes(sizeof(ProddableBlock), "addProddableBlock"); - - IF_DEBUG(linker, debugBelch("addProddableBlock: %p %p %d\n", oc, start, size)); - ASSERT(size > 0); - pb->start = start; - pb->size = size; - pb->next = oc->proddables; - oc->proddables = pb; -} - -void -checkProddableBlock (ObjectCode *oc, void *addr, size_t size ) -{ - ProddableBlock* pb; - - for (pb = oc->proddables; pb != NULL; pb = pb->next) { - char* s = (char*)(pb->start); - char* e = s + pb->size; - char* a = (char*)addr; - if (a >= s && (a+size) <= e) return; - } - barf("checkProddableBlock: invalid fixup in runtime linker: %p", addr); -} - -void freeProddableBlocks (ObjectCode *oc) -{ - ProddableBlock *pb, *next; - - for (pb = oc->proddables; pb != NULL; pb = next) { - next = pb->next; - stgFree(pb); - } - oc->proddables = NULL; -} - /* ----------------------------------------------------------------------------- * Section management. */ ===================================== rts/LinkerInternals.h ===================================== @@ -12,6 +12,7 @@ #include "RtsSymbols.h" #include "Hash.h" #include "linker/M32Alloc.h" +#include "linker/ProddableBlocks.h" #if RTS_LINKER_USE_MMAP #include <sys/mman.h> @@ -175,14 +176,6 @@ struct _Section { struct SectionFormatInfo* info; }; -typedef - struct _ProddableBlock { - void* start; - int size; - struct _ProddableBlock* next; - } - ProddableBlock; - typedef struct _Segment { void *start; /* page aligned start address of a segment */ size_t size; /* page rounded size of a segment */ @@ -328,7 +321,7 @@ struct _ObjectCode { /* SANITY CHECK ONLY: a list of the only memory regions which may safely be prodded during relocation. Any attempt to prod outside one of these is an error in the linker. */ - ProddableBlock* proddables; + ProddableBlockSet proddables; #if defined(NEED_SYMBOL_EXTRAS) SymbolExtra *symbol_extras; @@ -434,10 +427,6 @@ void exitLinker( void ); void freeObjectCode (ObjectCode *oc); SymbolAddr* loadSymbol(SymbolName *lbl, RtsSymbolInfo *pinfo); -void addProddableBlock ( ObjectCode* oc, void* start, int size ); -void checkProddableBlock (ObjectCode *oc, void *addr, size_t size ); -void freeProddableBlocks (ObjectCode *oc); - void addSection (Section *s, SectionKind kind, SectionAlloc alloc, void* start, StgWord size, StgWord mapped_offset, void* mapped_start, StgWord mapped_size); ===================================== rts/linker/Elf.c ===================================== @@ -924,7 +924,7 @@ ocGetNames_ELF ( ObjectCode* oc ) oc->sections[i].info->stubs = NULL; #endif - addProddableBlock(oc, start, size); + addProddableBlock(&oc->proddables, start, size); } else { addSection(&oc->sections[i], kind, alloc, oc->image+offset, size, 0, 0, 0); @@ -1272,7 +1272,7 @@ do_Elf_Rel_relocations ( ObjectCode* oc, char* ehdrC, debugBelch("Reloc: P = %p S = %p A = %p type=%d\n", (void*)P, (void*)S, (void*)A, reloc_type )); #if defined(DEBUG) - checkProddableBlock ( oc, pP, sizeof(Elf_Word) ); + checkProddableBlock ( &oc->proddables, pP, sizeof(Elf_Word) ); #else (void) pP; /* suppress unused varialbe warning in non-debug build */ #endif @@ -1684,7 +1684,7 @@ do_Elf_Rela_relocations ( ObjectCode* oc, char* ehdrC, #if defined(DEBUG) IF_DEBUG(linker_verbose,debugBelch("Reloc: P = %p S = %p A = %p\n", (void*)P, (void*)S, (void*)A )); - checkProddableBlock(oc, (void*)P, sizeof(Elf_Word)); + checkProddableBlock(&oc->proddables, (void*)P, sizeof(Elf_Word)); #endif #if defined(powerpc_HOST_ARCH) || defined(x86_64_HOST_ARCH) ===================================== rts/linker/MachO.c ===================================== @@ -253,7 +253,7 @@ resolveImports( return 0; } - checkProddableBlock(oc, + checkProddableBlock(&oc->proddables, ((void**)(oc->image + sect->offset)) + i, sizeof(void *)); ((void**)(oc->image + sect->offset))[i] = addr; @@ -287,7 +287,7 @@ decodeAddend(ObjectCode * oc, Section * section, MachORelocationInfo * ri) { /* the instruction. It is 32bit wide */ uint32_t * p = (uint32_t*)((uint8_t*)section->start + ri->r_address); - checkProddableBlock(oc, (void*)p, 1 << ri->r_length); + checkProddableBlock(&oc->proddables, (void*)p, 1 << ri->r_length); switch(ri->r_type) { case ARM64_RELOC_UNSIGNED: { @@ -364,7 +364,7 @@ encodeAddend(ObjectCode * oc, Section * section, MachORelocationInfo * ri, int64_t addend) { uint32_t * p = (uint32_t*)((uint8_t*)section->start + ri->r_address); - checkProddableBlock(oc, (void*)p, 1 << ri->r_length); + checkProddableBlock(&oc->proddables, (void*)p, 1 << ri->r_length); switch (ri->r_type) { case ARM64_RELOC_UNSIGNED: { @@ -788,7 +788,7 @@ relocateSection(ObjectCode* oc, int curSection) default: barf("Unknown size."); } - checkProddableBlock(oc,thingPtr,relocLenBytes); + checkProddableBlock(&oc->proddables,thingPtr,relocLenBytes); /* * With SIGNED_N the relocation is not at the end of the @@ -1034,9 +1034,9 @@ relocateSection(ObjectCode* oc, int curSection) */ if (0 == reloc->r_extern) { if (reloc->r_pcrel) { - checkProddableBlock(oc, (void *)((char *)thing + baseValue), 1); + checkProddableBlock(&oc->proddables, (void *)((char *)thing + baseValue), 1); } else { - checkProddableBlock(oc, (void *)thing, 1); + checkProddableBlock(&oc->proddables, (void *)thing, 1); } } @@ -1343,7 +1343,7 @@ ocGetNames_MachO(ObjectCode* oc) secArray[sec_idx].info->stub_size = 0; secArray[sec_idx].info->stubs = NULL; #endif - addProddableBlock(oc, start, section->size); + addProddableBlock(&oc->proddables, start, section->size); } curMem = (char*) secMem + section->size; ===================================== rts/linker/PEi386.c ===================================== @@ -1658,7 +1658,7 @@ ocGetNames_PEi386 ( ObjectCode* oc ) } addSection(section, kind, SECTION_NOMEM, start, sz, 0, 0, 0); - addProddableBlock(oc, oc->sections[i].start, sz); + addProddableBlock(&oc->proddables, oc->sections[i].start, sz); } /* Copy exported symbols into the ObjectCode. */ @@ -1690,7 +1690,7 @@ ocGetNames_PEi386 ( ObjectCode* oc ) SECTIONKIND_RWDATA, SECTION_MALLOC, bss, globalBssSize, 0, 0, 0); IF_DEBUG(linker_verbose, debugBelch("bss @ %p %" FMT_Word "\n", bss, globalBssSize)); - addProddableBlock(oc, bss, globalBssSize); + addProddableBlock(&oc->proddables, bss, globalBssSize); } else { addSection(&oc->sections[oc->n_sections-1], SECTIONKIND_OTHER, SECTION_NOMEM, NULL, 0, 0, 0, 0); @@ -2067,13 +2067,13 @@ ocResolve_PEi386 ( ObjectCode* oc ) IF_DEBUG(linker_verbose, debugBelch("S=%zx\n", S)); /* All supported relocations write at least 4 bytes */ - checkProddableBlock(oc, pP, 4); + checkProddableBlock(&oc->proddables, pP, 4); switch (reloc->Type) { #if defined(x86_64_HOST_ARCH) case 1: /* R_X86_64_64 (ELF constant 1) - IMAGE_REL_AMD64_ADDR64 (PE constant 1) */ { uint64_t A; - checkProddableBlock(oc, pP, 8); + checkProddableBlock(&oc->proddables, pP, 8); A = *(uint64_t*)pP; *(uint64_t *)pP = S + A; break; @@ -2114,7 +2114,7 @@ ocResolve_PEi386 ( ObjectCode* oc ) { /* mingw will emit this for a pc-rel 64 relocation */ uint64_t A; - checkProddableBlock(oc, pP, 8); + checkProddableBlock(&oc->proddables, pP, 8); A = *(uint64_t*)pP; *(uint64_t *)pP = S + A - (intptr_t)pP; break; ===================================== rts/linker/ProddableBlocks.c ===================================== @@ -0,0 +1,129 @@ +/* ----------------------------------------------------------------------------- + * + * (c) The GHC Team, 2025 + * + * RTS Object Linker + * + * ---------------------------------------------------------------------------*/ + + +/* + * Sanity checking. For each ObjectCode, maintain a list of address ranges + * which may be prodded during relocation, and abort if we try and write + * outside any of these. + */ + +#include "Rts.h" +#include "RtsUtils.h" +#include "linker/ProddableBlocks.h" + +#include <stdlib.h> +#include <string.h> + +typedef struct _ProddableBlock { + uintptr_t start; // inclusive + uintptr_t end; // inclusive +} ProddableBlock; + +void +initProddableBlockSet ( ProddableBlockSet* set ) +{ + set->data = NULL; + set->capacity = 0; + set->size = 0; +} + +void freeProddableBlocks (ProddableBlockSet *set) +{ + stgFree(set->data); + set->data = NULL; + set->size = 0; + set->capacity = 0; +} + +// Binary search for the first interval with start >= value. Returns index or +// size if none. +static size_t +findLower(const ProddableBlockSet *set, uintptr_t value) +{ + size_t l = 0; + size_t r = set->size; + while (l < r) { + size_t mid = l + (r - l) / 2; + if (set->data[mid].start < value) { + l = mid + 1; + } else { + r = mid; + } + } + return l; +} + +// Check whether a given value is a member of the set. +bool +containsSpan ( const ProddableBlockSet *set, uintptr_t start, uintptr_t end ) +{ + size_t i = findLower(set, start+1); + return i > 0 + && set->data[i-1].start <= start + && end <= set->data[i-1].end; +} + +void +checkProddableBlock (const ProddableBlockSet *set, void *addr, size_t size ) +{ + if (! containsSpan(set, (uintptr_t) addr, (uintptr_t) addr+size)) { + barf("checkProddableBlock: invalid fixup in runtime linker: %p", addr); + } +} + +// Ensure capacity for at least new_capacity intervals +static void +ensureCapacity(ProddableBlockSet *set, size_t new_capacity) { + if (new_capacity > set->capacity) { + size_t cap = set->capacity ? set->capacity * 2 : 4; + if (cap < new_capacity) { + cap = new_capacity; + } + ProddableBlock *tmp = stgReallocBytes(set->data, cap * sizeof(ProddableBlock), "addProddableBlock"); + set->data = tmp; + set->capacity = cap; + } +} + +void +addProddableBlock ( ProddableBlockSet* set, void* start_ptr, size_t size ) +{ + const uintptr_t start = (uintptr_t) start_ptr; + const uintptr_t end = (uintptr_t) start + size; + size_t i = findLower(set, start); + + // check previous interval if it is overlapping or adjacent + if (i > 0 && start <= set->data[i-1].end + 1) { + // merge with left interval + i--; + if (end > set->data[i].end) { + set->data[i].end = end; + } + } else { + // insert new interval + ensureCapacity(set, set->size + 1); + memmove(&set->data[i+1], &set->data[i], sizeof(ProddableBlock) * (set->size - i)); + set->data[i].start = start; + set->data[i].end = end; + set->size++; + } + + // coalesce overlaps on right + size_t j = i; + while (j < set->size && set->data[j].start <= set->data[i].end + 1) { + set->data[i].end = set->data[j].end; + j++; + } + + if (j != i) { + memmove(&set->data[i+1], &set->data[j], sizeof(ProddableBlock) * (set->size - j)); + set->size -= j - i - 1; + } +} + ===================================== rts/linker/ProddableBlocks.h ===================================== @@ -0,0 +1,38 @@ +/* ----------------------------------------------------------------------------- + * + * (c) The GHC Team, 2025 + * + * RTS Object Linker + * + * ---------------------------------------------------------------------------*/ + +#pragma once + +#include <stdbool.h> +#include <stddef.h> +#include <stdint.h> + +// An interval set on uintptr_t. +struct _ProddableBlock; + +typedef struct { + size_t size; + size_t capacity; + // sorted list of disjoint (start,end) pairs + struct _ProddableBlock *data; +} ProddableBlockSet; + +void initProddableBlockSet ( ProddableBlockSet* set ); + +// Insert an interval. +void addProddableBlock ( ProddableBlockSet* set, void* start, size_t size ); + +// Check that an address belongs to the set. +void checkProddableBlock (const ProddableBlockSet *set, void *addr, size_t size ); + + +// Free a set. +void freeProddableBlocks (ProddableBlockSet *set); + +// For testing. +bool containsSpan ( const ProddableBlockSet *set, uintptr_t start, uintptr_t end ); ===================================== rts/rts.cabal ===================================== @@ -491,6 +491,7 @@ library linker/MachO.c linker/macho/plt.c linker/macho/plt_aarch64.c + linker/ProddableBlocks.c linker/PEi386.c linker/SymbolExtras.c linker/elf_got.c View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/3b3a5decd11e7daffb758bd2f02aae… -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/3b3a5decd11e7daffb758bd2f02aae… You're receiving this email because of your account on gitlab.haskell.org.

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