February 2026 - ghc-commits

[Git][ghc/ghc][wip/marge_bot_batch_merge_job] 2 commits: testsuite: Explicitly use utf-8 encoding in rts-includes linter.
by Marge Bot (＠marge-bot) 04 Feb '26

04 Feb '26

Marge Bot pushed to branch wip/marge_bot_batch_merge_job at Glasgow Haskell Compiler / GHC Commits: d523ded8 by Andreas Klebinger at 2026-02-04T04:56:06-05:00 testsuite: Explicitly use utf-8 encoding in rts-includes linter. Not doing so caused failures on windows, as python failed to pick a reasonable encoding even with locale set. Fixes #26850 - - - - - f2387447 by Zubin Duggal at 2026-02-04T04:56:06-05:00 Bump transformers submodule to 0.6.3.0 Fixes #26790 - - - - - 2 changed files: - libraries/transformers - testsuite/tests/linters/regex-linters/check-rts-includes.py Changes: ===================================== libraries/transformers ===================================== @@ -1 +1 @@ -Subproject commit cee47cca7705edafe0a5839439e679edbd61890a +Subproject commit 0d615bc2457d5d2c695dcfdb902d88c1225beff3 ===================================== testsuite/tests/linters/regex-linters/check-rts-includes.py ===================================== @@ -12,12 +12,16 @@ import re INCLUDE_RE = re.compile('# *include ([<"][^">]+[>"])') def get_includes(file: Path) -> List[Tuple[int, str]]: - txt = file.read_text() - return [ (line_no+1, m.group(1) ) - for (line_no, line) in enumerate(txt.split('\n')) - for m in [INCLUDE_RE.match(line)] - if m is not None - if m.group(1) != "rts/PosixSource.h"] + try: + txt = file.read_text(encoding="utf-8") + return [ (line_no+1, m.group(1) ) + for (line_no, line) in enumerate(txt.split('\n')) + for m in [INCLUDE_RE.match(line)] + if m is not None + if m.group(1) != "rts/PosixSource.h"] + except Exception as e: + e.add_note(f"While reading includes from {file}") + raise def in_rts_dir(path: Path) -> bool: return len(path.parts) > 0 and path.parts[0] == 'rts' @@ -40,9 +44,14 @@ class RtsHIncludeOrderLinter(Linter): '"ghcplatform.h"', } - includes = get_includes(path) - headers = [x[1] for x in includes] - lines = path.read_text().split('\n') + try: + includes = get_includes(path) + headers = [x[1] for x in includes] + lines = path.read_text(encoding="utf-8").split('\n') + # #26850 + except Exception as e: + e.add_note(f"Error while decoding path {path}") + raise e if '"PosixSource.h"' in headers: for line_no, header in includes: @@ -69,18 +78,22 @@ class PrivateIncludeLinter(Linter): def lint(self, path: Path): private = False - lines = path.read_text().split('\n') - for line_no, include in get_includes(path): - if include == '"BeginPrivate.h"': - private = True - elif include == '"EndPrivate.h"': - private = False - elif private: - self.add_warning(Warning( - path=path, - line_no=line_no, - line_content=lines[line_no-1], - message='System header %s found inside of <BeginPrivate.h> block' % include)) + try: + lines = path.read_text(encoding="utf-8").split('\n') + for line_no, include in get_includes(path): + if include == '"BeginPrivate.h"': + private = True + elif include == '"EndPrivate.h"': + private = False + elif private: + self.add_warning(Warning( + path=path, + line_no=line_no, + line_content=lines[line_no-1], + message='System header %s found inside of <BeginPrivate.h> block' % include)) + except Exception as e: + e.add_note(f"While handling {path}") + raise e linters = [ RtsHIncludeOrderLinter(), View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/4628176246bfb9bb8a31fa782653ef… -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/4628176246bfb9bb8a31fa782653ef… You're receiving this email because of your account on gitlab.haskell.org.

1 0

[Git][ghc/ghc][wip/marge_bot_batch_merge_job] 8 commits: libraries: bump Cabal submodule to 3.16.1.0
by Marge Bot (＠marge-bot) 04 Feb '26

04 Feb '26

Marge Bot pushed to branch wip/marge_bot_batch_merge_job at Glasgow Haskell Compiler / GHC Commits: cd23d0ec by Cheng Shao at 2026-02-04T00:14:56-05:00 libraries: bump Cabal submodule to 3.16.1.0 - - - - - aba76a1b by Cheng Shao at 2026-02-04T00:14:56-05:00 libraries: bump deepseq submodule to 1.5.2.0 Also: - Get rid of usage of deprecated `NFData` function instance in the compiler - `T21391` still relies on `NFData` function instance, add `-Wno-deprecations` for the time being. - - - - - 1dcdbfb1 by Cheng Shao at 2026-02-04T00:14:56-05:00 libraries: bump directory submodule to 1.3.10.1 - - - - - 7122a7cd by Cheng Shao at 2026-02-04T00:14:56-05:00 libraries: bump exceptions submodule to 0.10.12 - - - - - b3dce1e9 by Cheng Shao at 2026-02-04T00:14:57-05:00 libraries: bump filepath submodule to 1.5.5.0 - - - - - e09d65a1 by Cheng Shao at 2026-02-04T00:14:57-05:00 libraries: bump os-string submodule to 2.0.10 - - - - - 8c8f3858 by Andreas Klebinger at 2026-02-04T00:14:57-05:00 testsuite: Explicitly use utf-8 encoding in rts-includes linter. Not doing so caused failures on windows, as python failed to pick a reasonable encoding even with locale set. Fixes #26850 - - - - - 46281762 by Zubin Duggal at 2026-02-04T00:14:58-05:00 Bump transformers submodule to 0.6.3.0 Fixes #26790 - - - - - 10 changed files: - compiler/GHC/Unit/Module/ModIface.hs - libraries/Cabal - libraries/deepseq - libraries/directory - libraries/exceptions - libraries/filepath - libraries/os-string - libraries/transformers - testsuite/tests/linters/regex-linters/check-rts-includes.py - testsuite/tests/simplCore/should_compile/T21391.hs Changes: ===================================== compiler/GHC/Unit/Module/ModIface.hs ===================================== @@ -894,13 +894,7 @@ instance (NFData (IfaceAbiHashesExts phase), NFData (IfaceDeclExts phase)) => NF `seq` rnf a14 instance NFData IfaceCache where - rnf (IfaceCache a1 a2 a3 a4) - = rnf a1 - `seq` rnf a2 - `seq` rnf a3 - `seq` rnf a4 - - + rnf = rwhnf forceModIface :: ModIface -> IO () forceModIface iface = () <$ (evaluate $ force iface) ===================================== libraries/Cabal ===================================== @@ -1 +1 @@ -Subproject commit d9b0904b49dc84e0bfc79062daf2bbdf9d22a422 +Subproject commit 8d1f5a33662be0db0654061fb53fb00e3f4417e0 ===================================== libraries/deepseq ===================================== @@ -1 +1 @@ -Subproject commit ae2762ac241a61852c9ff4c287af234fb1ad931f +Subproject commit 882f52f51854544a467babd8cb075e3271f5913e ===================================== libraries/directory ===================================== @@ -1 +1 @@ -Subproject commit 6442a3cf04f74d82cdf8c9213324313d52b23d28 +Subproject commit 8c712e834f277544fc03e96dfbbb769126dc0a7c ===================================== libraries/exceptions ===================================== @@ -1 +1 @@ -Subproject commit 81bfd6e0ca631f315658201ae02e30046678f056 +Subproject commit a3da039855479e3c8542e8b45986599d0414ff68 ===================================== libraries/filepath ===================================== @@ -1 +1 @@ -Subproject commit cbcd0ccf92f47e6c10fb9cc513a7b26facfc19fe +Subproject commit baac7d7e76449f76fc6785e77206edb5530b6bfb ===================================== libraries/os-string ===================================== @@ -1 +1 @@ -Subproject commit c08666bf7bf528e607fc1eacc20032ec59e69df3 +Subproject commit 71f66e1af2288867becaa567dfb10c1d791b0343 ===================================== libraries/transformers ===================================== @@ -1 +1 @@ -Subproject commit cee47cca7705edafe0a5839439e679edbd61890a +Subproject commit 0d615bc2457d5d2c695dcfdb902d88c1225beff3 ===================================== testsuite/tests/linters/regex-linters/check-rts-includes.py ===================================== @@ -12,12 +12,16 @@ import re INCLUDE_RE = re.compile('# *include ([<"][^">]+[>"])') def get_includes(file: Path) -> List[Tuple[int, str]]: - txt = file.read_text() - return [ (line_no+1, m.group(1) ) - for (line_no, line) in enumerate(txt.split('\n')) - for m in [INCLUDE_RE.match(line)] - if m is not None - if m.group(1) != "rts/PosixSource.h"] + try: + txt = file.read_text(encoding="utf-8") + return [ (line_no+1, m.group(1) ) + for (line_no, line) in enumerate(txt.split('\n')) + for m in [INCLUDE_RE.match(line)] + if m is not None + if m.group(1) != "rts/PosixSource.h"] + except Exception as e: + e.add_note(f"While reading includes from {file}") + raise def in_rts_dir(path: Path) -> bool: return len(path.parts) > 0 and path.parts[0] == 'rts' @@ -40,9 +44,14 @@ class RtsHIncludeOrderLinter(Linter): '"ghcplatform.h"', } - includes = get_includes(path) - headers = [x[1] for x in includes] - lines = path.read_text().split('\n') + try: + includes = get_includes(path) + headers = [x[1] for x in includes] + lines = path.read_text(encoding="utf-8").split('\n') + # #26850 + except Exception as e: + e.add_note(f"Error while decoding path {path}") + raise e if '"PosixSource.h"' in headers: for line_no, header in includes: @@ -69,18 +78,22 @@ class PrivateIncludeLinter(Linter): def lint(self, path: Path): private = False - lines = path.read_text().split('\n') - for line_no, include in get_includes(path): - if include == '"BeginPrivate.h"': - private = True - elif include == '"EndPrivate.h"': - private = False - elif private: - self.add_warning(Warning( - path=path, - line_no=line_no, - line_content=lines[line_no-1], - message='System header %s found inside of <BeginPrivate.h> block' % include)) + try: + lines = path.read_text(encoding="utf-8").split('\n') + for line_no, include in get_includes(path): + if include == '"BeginPrivate.h"': + private = True + elif include == '"EndPrivate.h"': + private = False + elif private: + self.add_warning(Warning( + path=path, + line_no=line_no, + line_content=lines[line_no-1], + message='System header %s found inside of <BeginPrivate.h> block' % include)) + except Exception as e: + e.add_note(f"While handling {path}") + raise e linters = [ RtsHIncludeOrderLinter(), ===================================== testsuite/tests/simplCore/should_compile/T21391.hs ===================================== @@ -2,6 +2,8 @@ {-# LANGUAGE GADTs #-} {-# LANGUAGE KindSignatures #-} {-# LANGUAGE RankNTypes #-} +{-# OPTIONS_GHC -Wno-deprecations #-} + module Web.Routing.SafeRouting where import Control.DeepSeq (NFData (..)) View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/16000e3575401e4ce9d19a69c6e813… -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/16000e3575401e4ce9d19a69c6e813… You're receiving this email because of your account on gitlab.haskell.org.

1 0

[Git][ghc/ghc][wip/T26503] Implement QualifiedStrings (#26503)
by Brandon Chinn (＠brandonchinn178) 04 Feb '26

04 Feb '26

Brandon Chinn pushed to branch wip/T26503 at Glasgow Haskell Compiler / GHC Commits: fbd62869 by Brandon Chinn at 2026-02-03T17:05:10-08:00 Implement QualifiedStrings (#26503) See Note [Implementation of QualifiedStrings] - - - - - 67 changed files: - compiler/GHC/Builtin/Types.hs - compiler/GHC/Driver/Flags.hs - compiler/GHC/Hs/Expr.hs - compiler/GHC/Hs/Instances.hs - compiler/GHC/Hs/Lit.hs - compiler/GHC/Hs/Pat.hs - compiler/GHC/Hs/Syn/Type.hs - compiler/GHC/Hs/Utils.hs - compiler/GHC/HsToCore/Expr.hs - compiler/GHC/HsToCore/Pmc/Desugar.hs - compiler/GHC/HsToCore/Quote.hs - compiler/GHC/HsToCore/Ticks.hs - compiler/GHC/Iface/Ext/Ast.hs - compiler/GHC/Parser.y - compiler/GHC/Parser/Errors/Ppr.hs - compiler/GHC/Parser/Errors/Types.hs - compiler/GHC/Parser/Lexer.x - compiler/GHC/Parser/PostProcess.hs - compiler/GHC/Parser/String.hs - compiler/GHC/Rename/Bind.hs - compiler/GHC/Rename/Expr.hs - + compiler/GHC/Rename/Lit.hs - compiler/GHC/Rename/Pat.hs - compiler/GHC/Tc/Gen/Expr.hs - compiler/GHC/Tc/Gen/Pat.hs - compiler/GHC/Tc/TyCl/PatSyn.hs - compiler/GHC/Tc/Types/Origin.hs - compiler/GHC/Tc/Zonk/Type.hs - compiler/GHC/Types/Error/Codes.hs - compiler/Language/Haskell/Syntax/Expr.hs - compiler/Language/Haskell/Syntax/Extension.hs - compiler/Language/Haskell/Syntax/Lit.hs - compiler/Language/Haskell/Syntax/Pat.hs - compiler/ghc.cabal.in - docs/users_guide/9.16.1-notes.rst - + docs/users_guide/exts/qualified_strings.rst - libraries/ghc-internal/src/GHC/Internal/LanguageExtensions.hs - testsuite/tests/driver/T4437.hs - testsuite/tests/ghc-api/annotations-literals/literals.stdout - testsuite/tests/interface-stability/template-haskell-exports.stdout - + testsuite/tests/qualified-strings/Makefile - + testsuite/tests/qualified-strings/should_compile/Example/Length.hs - + testsuite/tests/qualified-strings/should_compile/all.T - + testsuite/tests/qualified-strings/should_compile/qstrings_redundant_pattern.hs - + testsuite/tests/qualified-strings/should_compile/qstrings_redundant_pattern.stderr - + testsuite/tests/qualified-strings/should_fail/Example/Length.hs - + testsuite/tests/qualified-strings/should_fail/Makefile - + testsuite/tests/qualified-strings/should_fail/all.T - + testsuite/tests/qualified-strings/should_fail/qstrings_bad_expr.hs - + testsuite/tests/qualified-strings/should_fail/qstrings_bad_expr.stderr - + testsuite/tests/qualified-strings/should_fail/qstrings_bad_pat.hs - + testsuite/tests/qualified-strings/should_fail/qstrings_bad_pat.stderr - + testsuite/tests/qualified-strings/should_fail/qstrings_multiline_no_ext.hs - + testsuite/tests/qualified-strings/should_fail/qstrings_multiline_no_ext.stderr - + testsuite/tests/qualified-strings/should_run/Example/ByteStringAscii.hs - + testsuite/tests/qualified-strings/should_run/Example/ByteStringUtf8.hs - + testsuite/tests/qualified-strings/should_run/Example/Text.hs - + testsuite/tests/qualified-strings/should_run/Makefile - + testsuite/tests/qualified-strings/should_run/all.T - + testsuite/tests/qualified-strings/should_run/qstrings_expr.hs - + testsuite/tests/qualified-strings/should_run/qstrings_expr.stdout - + testsuite/tests/qualified-strings/should_run/qstrings_pat.hs - + testsuite/tests/qualified-strings/should_run/qstrings_pat.stdout - + testsuite/tests/qualified-strings/should_run/qstrings_th.hs - + testsuite/tests/qualified-strings/should_run/qstrings_th.stdout - utils/check-exact/ExactPrint.hs - utils/haddock/haddock-api/src/Haddock/Backends/Hyperlinker/Parser.hs The diff was not included because it is too large. View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/fbd6286948ba4ba2107331ca39d2ab8… -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/fbd6286948ba4ba2107331ca39d2ab8… You're receiving this email because of your account on gitlab.haskell.org.

1 0

[Git][ghc/ghc][wip/marge_bot_batch_merge_job] 11 commits: driver: Hide source paths at verbosity level 1 by default
by Marge Bot (＠marge-bot) 03 Feb '26

03 Feb '26

Marge Bot pushed to branch wip/marge_bot_batch_merge_job at Glasgow Haskell Compiler / GHC Commits: aa9c5e2c by Hécate Kleidukos at 2026-02-03T15:58:35-05:00 driver: Hide source paths at verbosity level 1 by default - - - - - c64cca1e by mangoiv at 2026-02-03T15:59:29-05:00 ExplicitLevelImports: check staging for types just like for values Previously, imported types were entirely exempted from staging checks as the implicit stage persistance assumed to be all imported types to be well staged. ExplicitLevelImports' change specification, however, does not do such an exemption. Thus we want to introduce such a check, just like we have for values. ExplicitLevelImports does not, however, talk about local names - from its perspective, we could theoretically keep treating locally introduced types specially - e.g. an ill-staged used in a quote would only emit a warning, not an error. To allow for a potential future migration away from such wrinkles as the staging check in notFound (see Note [Out of scope might be a staging error]) we consistently do the strict staging check that we also do for value if ExplicitLevelImports is on. Closes #26098 - - - - - 5f0dbeb6 by Simon Hengel at 2026-02-03T16:00:12-05:00 Use Haddock formatting in deprecation message of `initNameCache` - - - - - 522afda6 by Cheng Shao at 2026-02-03T18:35:10-05:00 libraries: bump Cabal submodule to 3.16.1.0 - - - - - 8f6fcced by Cheng Shao at 2026-02-03T18:35:10-05:00 libraries: bump deepseq submodule to 1.5.2.0 Also: - Get rid of usage of deprecated `NFData` function instance in the compiler - `T21391` still relies on `NFData` function instance, add `-Wno-deprecations` for the time being. - - - - - 31ea6798 by Cheng Shao at 2026-02-03T18:35:10-05:00 libraries: bump directory submodule to 1.3.10.1 - - - - - 56f3f5a0 by Cheng Shao at 2026-02-03T18:35:11-05:00 libraries: bump exceptions submodule to 0.10.12 - - - - - f335ca7b by Cheng Shao at 2026-02-03T18:35:11-05:00 libraries: bump filepath submodule to 1.5.5.0 - - - - - a064873d by Cheng Shao at 2026-02-03T18:35:11-05:00 libraries: bump os-string submodule to 2.0.10 - - - - - 5ae12c4a by Andreas Klebinger at 2026-02-03T18:35:12-05:00 testsuite: Explicitly use utf-8 encoding in rts-includes linter. Not doing so caused failures on windows, as python failed to pick a reasonable encoding even with locale set. Fixes #26850 - - - - - 16000e35 by Zubin Duggal at 2026-02-03T18:35:12-05:00 Bump transformers submodule to 0.6.3.0 Fixes #26790 - - - - - 55 changed files: - compiler/GHC/Driver/Session.hs - compiler/GHC/Rename/HsType.hs - compiler/GHC/Rename/Splice.hs-boot - compiler/GHC/Types/Name/Cache.hs - compiler/GHC/Unit/Module/ModIface.hs - docs/users_guide/9.16.1-notes.rst - hadrian/src/Settings/Builders/RunTest.hs - libraries/Cabal - libraries/deepseq - libraries/directory - libraries/exceptions - libraries/filepath - libraries/os-string - libraries/transformers - testsuite/mk/test.mk - testsuite/tests/backpack/cabal/bkpcabal08/bkpcabal08.stdout - testsuite/tests/driver/T20030/test1/all.T - testsuite/tests/driver/T20030/test2/all.T - testsuite/tests/driver/T20030/test3/all.T - testsuite/tests/driver/T20030/test4/all.T - testsuite/tests/driver/T20030/test5/all.T - testsuite/tests/driver/T20030/test6/all.T - testsuite/tests/driver/T8526/T8526.script - testsuite/tests/driver/bytecode-object/Makefile - testsuite/tests/driver/bytecode-object/bytecode_object19.stdout - testsuite/tests/driver/dynamicToo/dynamicToo001/Makefile - testsuite/tests/driver/fat-iface/fat014.script - testsuite/tests/driver/implicit-dyn-too/Makefile - testsuite/tests/driver/multipleHomeUnits/all.T - testsuite/tests/driver/multipleHomeUnits/multipleHomeUnits_recomp_th.stdout - − testsuite/tests/ghci/linking/T11531.stderr - testsuite/tests/ghci/prog018/prog018.script - testsuite/tests/ghci/scripts/T13869.script - testsuite/tests/ghci/scripts/T13997.script - testsuite/tests/ghci/scripts/T17669.script - testsuite/tests/ghci/scripts/T18330.script - testsuite/tests/ghci/scripts/T18330.stdout - testsuite/tests/ghci/scripts/T1914.script - testsuite/tests/ghci/scripts/T20217.script - testsuite/tests/ghci/scripts/T6105.script - testsuite/tests/ghci/scripts/T8042.script - testsuite/tests/ghci/scripts/T8042recomp.script - testsuite/tests/ghci/should_run/Makefile - testsuite/tests/linters/regex-linters/check-rts-includes.py - testsuite/tests/rts/T13676.script - testsuite/tests/simplCore/should_compile/T21391.hs - + testsuite/tests/th/T26098A_quote.hs - + testsuite/tests/th/T26098A_splice.hs - + testsuite/tests/th/T26098_local.hs - + testsuite/tests/th/T26098_local.stderr - + testsuite/tests/th/T26098_quote.hs - + testsuite/tests/th/T26098_quote.stderr - + testsuite/tests/th/T26098_splice.hs - + testsuite/tests/th/T26098_splice.stderr - testsuite/tests/th/all.T The diff was not included because it is too large. View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/e346f59c8813e604c60fbc430276b8… -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/e346f59c8813e604c60fbc430276b8… You're receiving this email because of your account on gitlab.haskell.org.

1 0

[Git][ghc/ghc][wip/T26868] comments only [skip ci]
by Simon Peyton Jones (＠simonpj) 03 Feb '26

03 Feb '26

Simon Peyton Jones pushed to branch wip/T26868 at Glasgow Haskell Compiler / GHC Commits: 1b25d8b1 by Simon Peyton Jones at 2026-02-03T22:39:37+00:00 comments only [skip ci] - - - - - 2 changed files: - compiler/GHC/Core.hs - compiler/GHC/Core/Lint.hs Changes: ===================================== compiler/GHC/Core.hs ===================================== @@ -365,33 +365,70 @@ Note [Shadowing in Core] You might wonder if there is an invariant that a Core expression has no "shadowing". For example, is this illegal? \x. \x. blah -- x is shadowed -Answer; no! Core does /not/ have a no-shadowing invariant. -Neither the simplifier nor any other pass GUARANTEES that shadowing is -avoided. Thus, all passes SHOULD work fine even in the presence of -arbitrary shadowing in their inputs. +Answer: +* No! Core does /not/ have a no-shadowing invariant; + That is, we allow (\x. (x, \x. x)) + See the rest of this note -So the Unique in a Var is not really unique at all. Still, it's very -useful to give a constant-time equality/ordering for Vars, and to give -a key that can be used to make sets of Vars (VarSet), or mappings from -Vars to other things (VarEnv). Moreover, if you do want to eliminate -shadowing, you can give a new Unique to an Id without changing its -printable name, which makes debugging easier. +* But Core /does/ have a no-type-shadowing invariant; + See Note [No type-shadowing in Core] It would in many ways be easier to have a no-shadowing invariant. And the Simplifier does its best to clone variables that are shadowed. But it is extremely difficult to GUARANTEE it: -* We use `GHC.Types.Id.mkTemplateLocal` to make up local binders, with uniques - that are locally-unique (enough for the purpose) but not globally unique. - It is convenient not to have to plumb a unique supply to these functions. + * We use `GHC.Types.Id.mkTemplateLocal` to make up local binders, with uniques + that are locally-unique (enough for the purpose) but not globally unique. + It is convenient not to have to plumb a unique supply to these functions. -* It is very difficult for the Simplifier to gurantee a no-shadowing result. - See Note [Shadowing in the Simplifier] in GHC.Core.Opt.Simplify.Iteration. + * It is very difficult for the Simplifier to gurantee a no-shadowing result. + See Note [Shadowing in the Simplifier] in GHC.Core.Opt.Simplify.Iteration. -* See Note [Shadowing in CSE] in GHC.Core.Opt.CSE + * See Note [Shadowing in CSE] in GHC.Core.Opt.CSE -* See Note [Shadowing in SpecConstr] in GHC.Core.Opt.SpecContr + * See Note [Shadowing in SpecConstr] in GHC.Core.Opt.SpecContr + +TL;DR: neither the simplifier nor any other pass GUARANTEES that shadowing is +avoided. Thus, all passes MUST work fine even in the presence of arbitrary +shadowing in their inputs. + +So the Unique in a Var is not really unique at all. Still, it's very useful to +give a constant-time equality/ordering for Vars, and to give a key that can be +used to make sets of Vars (VarSet), or mappings from Vars to other things +(VarEnv). Moreover, if you do want to eliminate shadowing, you can give a new +Unique to an Id without changing its printable name, which makes debugging +easier. + +Note [No type-shadowing in Core] +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +Consider applying `exprType` to this term: + + /\a. \(x::[a]). /\a. \(y::a). (x,y) + +where we have genuine shadowing: both lambdas bind the same a. Remember: every +occurrence of `x` is just a copy of the binder (x::[a]), and ditto `y`. + +Now what does `exprType` return for that term? It will return the bogus type + + forall a. [a] -> forall a. a -> ([a],a) + +whereas the correct type is: forall a. [a] -> forall b. b -> ([a],b) +where we rename the inner forall. + +It would be /possible/ to make `exprType` more complicated, so that it does +renaming on the fly. But instead we impose the no-type-shadowing invariant on +Core: the variable free in an Id's type must be in scope at all that Id's +occurrences. In type-system terms: + + fv(t) are not bound in G2 + ------------------------- + G1, x:t, G2 |- x : t + +How do we guarntee this invariant? The main thing that might disturb it is +/substitution/. + + ... TODO say more here ... Note [Core letrec invariant] ~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ===================================== compiler/GHC/Core/Lint.hs ===================================== @@ -2958,6 +2958,12 @@ lint_axiom_pair tc (ax1, ax2) -} type LintLevel = Int +-- A LintLevel tracks how many local variables are in scope. It is used to detect when +-- the free variables in a binder's type have been shadowed (which is not allowed): +-- Whenever we look up a variable v at an occurrence, we additionally look up all of the +-- variables fvs free in v's type. If the LintLevel of any of the fvs is greater than +-- that of v, we know we have a shadowed tyvar (or covar) and should issue an error. +-- See (SIC2) in Note [Shadowing in Core] in GHC.Core -- If you edit this type, you may need to update the GHC formalism -- See Note [GHC Formalism] View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/1b25d8b18530b3648359279dfda4ff6… -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/1b25d8b18530b3648359279dfda4ff6… You're receiving this email because of your account on gitlab.haskell.org.

1 0

[Git][ghc/ghc][wip/T24464] Simplify the treatment of static forms
by Simon Peyton Jones (＠simonpj) 03 Feb '26

03 Feb '26

Simon Peyton Jones pushed to branch wip/T24464 at Glasgow Haskell Compiler / GHC Commits: 4b1048a3 by Simon Peyton Jones at 2026-02-03T22:38:40+00:00 Simplify the treatment of static forms This MR implements GHC proposal 732: simplify static forms, https://github.com/ghc-proposals/ghc-proposals/pull/732 thereby addressing #26556. See `Note [Grand plan for static forms]` in GHC.Iface.Tidy.StaticPtrTable The main changes are: * There is a new, simple rule for (static e), namely that the free term variables of `e` must be bound at top level. The check is done in the `HsStatic` case of `GHC.Rename.Expr.rnExpr` * That in turn substantially simplifies the info that the typechecker carries around in its type environment. Hooray. * The desugarer emits static bindings to top level directly; see the `HsStatic` case of `dsExpr`. * There is no longer any special static-related magic in the FloatOut pass. And the main Simplifier pipeline no longer needs a special case to run FloatOut even with -O0. Hooray. All this forced an unexpected change to the pattern match checker. It recursively invokes the main Hs desugarer when it wants to take a look at a term to spot some special cases (notably constructor applications). We don't want to emit any nested (static e) bindings to top level a second time! Yikes. That forced a modest refactor in GHC.HsToCore.Pmc: * The `dsl_nablas` field of `DsLclEnv` now has a `NoPmc` case, which says "I'm desugaring just for pattern-match checking purposes". * When that flag is set we don't emit static binds. That in turn forces a cascade of refactoring, but the net effect is an improvement; less risk of duplicated (even exponential?) work. 10% metric decrease, on some architectures, of compile-time max-bytes-used on T15304. Metric Decrease: T15304 - - - - - 59 changed files: - compiler/GHC/Core/Lint.hs - compiler/GHC/Core/Opt/Pipeline.hs - compiler/GHC/Core/Opt/SetLevels.hs - compiler/GHC/CoreToStg/AddImplicitBinds.hs - compiler/GHC/Driver/Config/Core/Lint.hs - compiler/GHC/Hs/Binds.hs - compiler/GHC/Hs/Decls.hs - compiler/GHC/Hs/Expr.hs - compiler/GHC/Hs/Instances.hs - compiler/GHC/Hs/Syn/Type.hs - compiler/GHC/Hs/Utils.hs - compiler/GHC/HsToCore.hs - compiler/GHC/HsToCore/Docs.hs - compiler/GHC/HsToCore/Expr.hs - compiler/GHC/HsToCore/GuardedRHSs.hs - compiler/GHC/HsToCore/Match.hs - compiler/GHC/HsToCore/Monad.hs - compiler/GHC/HsToCore/Pmc.hs - compiler/GHC/HsToCore/Pmc/Desugar.hs - compiler/GHC/HsToCore/Quote.hs - compiler/GHC/HsToCore/Ticks.hs - compiler/GHC/HsToCore/Types.hs - compiler/GHC/Iface/Ext/Ast.hs - compiler/GHC/Iface/Tidy.hs - compiler/GHC/Iface/Tidy/StaticPtrTable.hs - compiler/GHC/Rename/Bind.hs - compiler/GHC/Rename/Expr.hs - compiler/GHC/Rename/Module.hs - compiler/GHC/Tc/Deriv.hs - compiler/GHC/Tc/Errors/Ppr.hs - compiler/GHC/Tc/Errors/Types.hs - compiler/GHC/Tc/Gen/Bind.hs - compiler/GHC/Tc/Gen/Expr.hs - compiler/GHC/Tc/Gen/Head.hs - compiler/GHC/Tc/Gen/Pat.hs - compiler/GHC/Tc/Gen/Sig.hs - compiler/GHC/Tc/Module.hs - compiler/GHC/Tc/Solver.hs - compiler/GHC/Tc/Solver/Monad.hs - compiler/GHC/Tc/TyCl/Instance.hs - compiler/GHC/Tc/TyCl/Utils.hs - compiler/GHC/Tc/Types.hs - compiler/GHC/Tc/Types/BasicTypes.hs - compiler/GHC/Tc/Types/Constraint.hs - compiler/GHC/Tc/Types/Origin.hs - compiler/GHC/Tc/Utils/Env.hs - compiler/GHC/Tc/Utils/Monad.hs - − compiler/GHC/Tc/Utils/TcMType.hs-boot - compiler/GHC/Tc/Zonk/TcType.hs - compiler/GHC/Tc/Zonk/Type.hs - compiler/GHC/Types/Id/Make.hs - testsuite/tests/codeGen/should_run/CgStaticPointers.hs - testsuite/tests/codeGen/should_run/CgStaticPointersNoFullLazyness.hs - testsuite/tests/ghci/scripts/T20150.stdout - testsuite/tests/parser/should_compile/DumpRenamedAst.stderr - testsuite/tests/parser/should_compile/T14189.stderr - testsuite/tests/rename/should_fail/RnStaticPointersFail01.stderr - testsuite/tests/rename/should_fail/RnStaticPointersFail03.stderr - testsuite/tests/warnings/should_fail/CaretDiagnostics1.stderr The diff was not included because it is too large. View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/4b1048a305181d6b94b888975a36f01… -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/4b1048a305181d6b94b888975a36f01… You're receiving this email because of your account on gitlab.haskell.org.

1 0

[Git][ghc/ghc][wip/T24464] 17 commits: Remove `GHC.Desugar` from `base`
by Simon Peyton Jones (＠simonpj) 03 Feb '26

03 Feb '26

Simon Peyton Jones pushed to branch wip/T24464 at Glasgow Haskell Compiler / GHC Commits: 607b287b by Wolfgang Jeltsch at 2026-01-28T15:41:53+02:00 Remove `GHC.Desugar` from `base` `GHC.Desugar` was deprecated and should have been removed in GHC 9.14. However, the removal was forgotten, although there was a code block that was intended to trigger a compilation error when the GHC version in use was 9.14 or later. This code sadly didn’t work, because the `__GLASGOW_HASKELL__` macro was misspelled as `__GLASGOW_HASKELL`. - - - - - e8f5a45d by sterni at 2026-01-29T04:19:18-05:00 users_guide: fix runtime error during build with Sphinx 9.1.0 Appears that pathto is stricter about what it accepts now. Tested Sphinx 8.2.3 and 9.1.0 on the ghc-9.10 branch. Resolves #26810. Co-authored-by: Martin Weinelt <hexa(a)darmstadt.ccc.de> - - - - - ce2d62fb by Jessica Clarke at 2026-01-29T19:48:51-05:00 PPC NCG: Use libcall for 64-bit cmpxchg on 32-bit PowerPC There is no native instruction for this, and even if there were a register pair version we could use, the implementation here is assuming the values fit in a single register, and we end up only using / defining the low halves of the registers. Fixes: b4d39adbb5 ("PrimOps: Add CAS op for all int sizes") Fixes: #23969 - - - - - 43d97761 by Michael Karcher at 2026-01-29T19:49:43-05:00 NCG for PPC: add pattern for CmmRegOff to iselExpr64 Closes #26828 - - - - - aeeb4a20 by Matthew Pickering at 2026-01-30T11:42:47-05:00 determinism: Use deterministic map for Strings in TyLitMap When generating typeable evidence the types we need evidence for all cached in a TypeMap, the order terms are retrieved from a type map determines the order the bindings appear in the program. A TypeMap is quite diligent to use deterministic maps, apart from in the TyLitMap, which uses a UniqFM for storing strings, whose ordering depends on the Unique of the FastString. This can cause non-deterministic .hi and .o files. An unexpected side-effect is the error message but RecordDotSyntaxFail8 changing. I looked into this with Sam and this change caused the constraints to be solved in a different order which results in a slightly different error message. I have accepted the new test, since the output before was non-deterministic and the new output is consistent with the other messages in that file. Fixes #26846 - - - - - 9e4d70c2 by Andrew Lelechenko at 2026-01-30T11:43:29-05:00 Upgrade text submodule to 2.1.4 - - - - - 631fa5ae by Recursion Ninja at 2026-01-31T22:30:11+00:00 Decouple `L.S.H.Decls` from importing `GHC.Types.Basic` Data-types within `GHC.Types.Basic` which describe components of the AST are migrated to `Language.Haskell.Syntax.Basic`. Related function definitions are also moved. Types moved to L.H.S. because they are part of the AST: * TopLevelFlag * RuleName Types moved from L.H.S. to GHC.Hs. because they are not needed in the AST: * TyConFlavour * TypeOrData * NewOrData Migrated instances: * `Outputable` instances moved to in `GHC.Utils.Outputable` * `Binary` instance of `Boxity` moved to to `GHC.Utils.Binary` * Other `Binary` instances are orphans to be migrated later. The `OverlapMode` data-type is given a TTG extension point. The `OverlapFlag` data-type, which depends on `OverlapMode`, is updated to support `OverlapMode` with a GHC "pass" type paramerter. In order to avoid module import cycles, `OverlapMode` and `OverlapFlag` are migrated to new modules (no way around this). * Migrated `OverlapMode` to new module `Language.Haskell.Syntax.Overlap` * Migrated `OverlapFlag` to new module `GHC.Hs.Decls.Overlap` - - - - - 9769cc03 by Simon Hengel at 2026-02-01T04:21:03-05:00 Update the documentation for MultiWayIf (fixes #25376) (so that it matches the implementation) - - - - - 5fc9442a by Peter Trommler at 2026-02-01T04:21:44-05:00 hadrian: Fix dependency generation for assembler Assembler files allow # for comments unless in column 1. A modern cpp for C treats those a preprocessor directives. We tell gcc that a .S file is assembler with cpp and not C. Fixes #26819 - - - - - 269c4087 by Simon Peyton Jones at 2026-02-01T19:38:10-05:00 Include current phase in the range for rule/unfoldings This MR fixes a bad loop in the compiler: #26826. The fix is to add (WAR2) to Note [What is active in the RHS of a RULE or unfolding?] in GHC.Core.Opt.Simplify.Utils - - - - - ddf1434f by Vladislav Zavialov at 2026-02-01T19:38:52-05:00 Refactor: merge HsMultilineString into HsString (#26860) Before this patch, HsLit defined two separate constructors to represent single-line and multi-line strings: data HsLit x ... | HsString (XHsString x) FastString | HsMultilineString (XHsMultilineString x) FastString I found this to be an unnecessary complication and an obstacle to unifying HsLit with HsTyLit. Now we use HsString for both kinds of literals. One user-facing change here is `ppr (HsString st s)` behaving differently for single-line strings containing newlines: x = "first line \ \asdf\n\ \second line" Previously, the literal was fed to `ftext` with its newlines, producing an ill-formed SDoc. This issue is now addressed by using `split` for both single-line and multi-line strings: vcat $ map text $ split '\n' (unpackFS src) See the parser/should_fail/T26860ppr test. In addition (and unrelatedly to the main payload of this patch), drop the unused pmPprHsLit helper. - - - - - 2b4f463c by Simon Peyton Jones at 2026-02-02T17:32:32+00:00 Remove exprIsCheap from doFloatFromRhs See #26854 and Note [Float when expandable] This patch simplifies the code, by removing an extra unnecessary test. - - - - - 9db7f21f by Brandon Chinn at 2026-02-03T09:15:10-05:00 Refactor: make function patterns exhaustive Also added missing (==) logic for: * HsMultilineString * HsInt{8,16,32} * HsWord{8,16,32} - - - - - aa9c5e2c by Hécate Kleidukos at 2026-02-03T15:58:35-05:00 driver: Hide source paths at verbosity level 1 by default - - - - - c64cca1e by mangoiv at 2026-02-03T15:59:29-05:00 ExplicitLevelImports: check staging for types just like for values Previously, imported types were entirely exempted from staging checks as the implicit stage persistance assumed to be all imported types to be well staged. ExplicitLevelImports' change specification, however, does not do such an exemption. Thus we want to introduce such a check, just like we have for values. ExplicitLevelImports does not, however, talk about local names - from its perspective, we could theoretically keep treating locally introduced types specially - e.g. an ill-staged used in a quote would only emit a warning, not an error. To allow for a potential future migration away from such wrinkles as the staging check in notFound (see Note [Out of scope might be a staging error]) we consistently do the strict staging check that we also do for value if ExplicitLevelImports is on. Closes #26098 - - - - - 5f0dbeb6 by Simon Hengel at 2026-02-03T16:00:12-05:00 Use Haddock formatting in deprecation message of `initNameCache` - - - - - 3f9f6362 by Simon Peyton Jones at 2026-02-03T22:12:42+00:00 Simplify the treatment of static forms This MR implements GHC proposal 732: simplify static forms, https://github.com/ghc-proposals/ghc-proposals/pull/732 thereby addressing #26556. See `Note [Grand plan for static forms]` in GHC.Iface.Tidy.StaticPtrTable The main changes are: * There is a new, simple rule for (static e), namely that the free term variables of `e` must be bound at top level. The check is done in the `HsStatic` case of `GHC.Rename.Expr.rnExpr` * That in turn substantially simplifies the info that the typechecker carries around in its type environment. Hooray. * The desugarer emits static bindings to top level directly; see the `HsStatic` case of `dsExpr`. * There is no longer any special static-related magic in the FloatOut pass. And the main Simplifier pipeline no longer needs a special case to run FloatOut even with -O0. Hooray. All this forced an unexpected change to the pattern match checker. It recursively invokes the main Hs desugarer when it wants to take a look at a term to spot some special cases (notably constructor applications). We don't want to emit any nested (static e) bindings to top level a second time! Yikes. That forced a modest refactor in GHC.HsToCore.Pmc: * The `dsl_nablas` field of `DsLclEnv` now has a `NoPmc` case, which says "I'm desugaring just for pattern-match checking purposes". * When that flag is set we don't emit static binds. That in turn forces a cascade of refactoring, but the net effect is an improvement; less risk of duplicated (even exponential?) work. 10% metric decrease, on some architectures, of compile-time max-bytes-used on T15304. Metric Decrease: T15304 - - - - - 165 changed files: - compiler/GHC/CmmToAsm/PPC/CodeGen.hs - compiler/GHC/Core/InstEnv.hs - compiler/GHC/Core/Lint.hs - compiler/GHC/Core/Map/Type.hs - compiler/GHC/Core/Opt/OccurAnal.hs - compiler/GHC/Core/Opt/Pipeline.hs - compiler/GHC/Core/Opt/SetLevels.hs - compiler/GHC/Core/Opt/Simplify/Env.hs - compiler/GHC/Core/Opt/Simplify/Utils.hs - compiler/GHC/Core/Opt/WorkWrap.hs - compiler/GHC/CoreToStg/AddImplicitBinds.hs - compiler/GHC/Driver/Config/Core/Lint.hs - compiler/GHC/Driver/Session.hs - compiler/GHC/Hs/Binds.hs - compiler/GHC/Hs/Decls.hs - + compiler/GHC/Hs/Decls/Overlap.hs - compiler/GHC/Hs/Expr.hs - compiler/GHC/Hs/Instances.hs - compiler/GHC/Hs/Lit.hs - compiler/GHC/Hs/Syn/Type.hs - compiler/GHC/Hs/Utils.hs - compiler/GHC/HsToCore.hs - compiler/GHC/HsToCore/Docs.hs - compiler/GHC/HsToCore/Errors/Types.hs - compiler/GHC/HsToCore/Expr.hs - compiler/GHC/HsToCore/GuardedRHSs.hs - compiler/GHC/HsToCore/Match.hs - compiler/GHC/HsToCore/Match/Literal.hs - compiler/GHC/HsToCore/Monad.hs - compiler/GHC/HsToCore/Pmc.hs - compiler/GHC/HsToCore/Pmc/Desugar.hs - compiler/GHC/HsToCore/Quote.hs - compiler/GHC/HsToCore/Ticks.hs - compiler/GHC/HsToCore/Types.hs - compiler/GHC/Iface/Ext/Ast.hs - compiler/GHC/Iface/Syntax.hs - compiler/GHC/Iface/Tidy.hs - compiler/GHC/Iface/Tidy/StaticPtrTable.hs - compiler/GHC/Parser.y - compiler/GHC/Parser/String.hs - compiler/GHC/Rename/Bind.hs - compiler/GHC/Rename/Env.hs - compiler/GHC/Rename/Expr.hs - compiler/GHC/Rename/HsType.hs - compiler/GHC/Rename/Module.hs - compiler/GHC/Rename/Names.hs - compiler/GHC/Rename/Splice.hs - compiler/GHC/Rename/Splice.hs-boot - compiler/GHC/Tc/Deriv.hs - compiler/GHC/Tc/Deriv/Utils.hs - compiler/GHC/Tc/Errors/Ppr.hs - compiler/GHC/Tc/Errors/Types.hs - compiler/GHC/Tc/Gen/Bind.hs - compiler/GHC/Tc/Gen/Expr.hs - compiler/GHC/Tc/Gen/Head.hs - compiler/GHC/Tc/Gen/HsType.hs - compiler/GHC/Tc/Gen/Pat.hs - compiler/GHC/Tc/Gen/Sig.hs - compiler/GHC/Tc/Module.hs - compiler/GHC/Tc/Solver.hs - compiler/GHC/Tc/Solver/Monad.hs - compiler/GHC/Tc/TyCl/Instance.hs - compiler/GHC/Tc/TyCl/Utils.hs - compiler/GHC/Tc/Types.hs - compiler/GHC/Tc/Types/BasicTypes.hs - compiler/GHC/Tc/Types/Constraint.hs - compiler/GHC/Tc/Types/Origin.hs - compiler/GHC/Tc/Utils/Env.hs - compiler/GHC/Tc/Utils/Instantiate.hs - compiler/GHC/Tc/Utils/Monad.hs - − compiler/GHC/Tc/Utils/TcMType.hs-boot - compiler/GHC/Tc/Zonk/TcType.hs - compiler/GHC/Tc/Zonk/Type.hs - compiler/GHC/ThToHs.hs - compiler/GHC/Types/Basic.hs - compiler/GHC/Types/Id/Make.hs - compiler/GHC/Types/InlinePragma.hs - compiler/GHC/Types/Name.hs - compiler/GHC/Types/Name/Cache.hs - compiler/GHC/Unit/Types.hs - compiler/GHC/Utils/Binary.hs - compiler/GHC/Utils/Outputable.hs - compiler/Language/Haskell/Syntax/Basic.hs - compiler/Language/Haskell/Syntax/Decls.hs - + compiler/Language/Haskell/Syntax/Decls/Overlap.hs - compiler/Language/Haskell/Syntax/Extension.hs - compiler/Language/Haskell/Syntax/Lit.hs - compiler/ghc.cabal.in - docs/users_guide/9.16.1-notes.rst - docs/users_guide/exts/multiway_if.rst - docs/users_guide/rtd-theme/layout.html - hadrian/src/Builder.hs - hadrian/src/Rules/Compile.hs - hadrian/src/Settings/Builders/Cc.hs - hadrian/src/Settings/Builders/RunTest.hs - hadrian/src/Settings/Packages.hs - libraries/base/base.cabal.in - − libraries/base/src/GHC/Desugar.hs - libraries/text - testsuite/mk/test.mk - testsuite/tests/backpack/cabal/bkpcabal08/bkpcabal08.stdout - testsuite/tests/codeGen/should_run/CgStaticPointers.hs - testsuite/tests/codeGen/should_run/CgStaticPointersNoFullLazyness.hs - testsuite/tests/count-deps/CountDepsAst.stdout - testsuite/tests/count-deps/CountDepsParser.stdout - testsuite/tests/driver/T20030/test1/all.T - testsuite/tests/driver/T20030/test2/all.T - testsuite/tests/driver/T20030/test3/all.T - testsuite/tests/driver/T20030/test4/all.T - testsuite/tests/driver/T20030/test5/all.T - testsuite/tests/driver/T20030/test6/all.T - testsuite/tests/driver/T8526/T8526.script - testsuite/tests/driver/bytecode-object/Makefile - testsuite/tests/driver/bytecode-object/bytecode_object19.stdout - testsuite/tests/driver/dynamicToo/dynamicToo001/Makefile - testsuite/tests/driver/fat-iface/fat014.script - testsuite/tests/driver/implicit-dyn-too/Makefile - testsuite/tests/driver/multipleHomeUnits/all.T - testsuite/tests/driver/multipleHomeUnits/multipleHomeUnits_recomp_th.stdout - + testsuite/tests/ghc-api/TypeMapStringLiteral.hs - testsuite/tests/ghc-api/all.T - − testsuite/tests/ghci/linking/T11531.stderr - testsuite/tests/ghci/prog018/prog018.script - testsuite/tests/ghci/scripts/T13869.script - testsuite/tests/ghci/scripts/T13997.script - testsuite/tests/ghci/scripts/T17669.script - testsuite/tests/ghci/scripts/T18330.script - testsuite/tests/ghci/scripts/T18330.stdout - testsuite/tests/ghci/scripts/T1914.script - testsuite/tests/ghci/scripts/T20150.stdout - testsuite/tests/ghci/scripts/T20217.script - testsuite/tests/ghci/scripts/T6105.script - testsuite/tests/ghci/scripts/T8042.script - testsuite/tests/ghci/scripts/T8042recomp.script - testsuite/tests/ghci/should_run/Makefile - testsuite/tests/interface-stability/base-exports.stdout - testsuite/tests/interface-stability/base-exports.stdout-javascript-unknown-ghcjs - testsuite/tests/interface-stability/base-exports.stdout-mingw32 - testsuite/tests/interface-stability/base-exports.stdout-ws-32 - testsuite/tests/parser/should_compile/DumpRenamedAst.stderr - testsuite/tests/parser/should_compile/T14189.stderr - testsuite/tests/parser/should_fail/RecordDotSyntaxFail8.stderr - + testsuite/tests/parser/should_fail/T26860ppr.hs - + testsuite/tests/parser/should_fail/T26860ppr.stderr - testsuite/tests/parser/should_fail/all.T - testsuite/tests/rename/should_fail/RnStaticPointersFail01.stderr - testsuite/tests/rename/should_fail/RnStaticPointersFail03.stderr - testsuite/tests/rts/T13676.script - + testsuite/tests/simplCore/should_compile/T26826.hs - testsuite/tests/simplCore/should_compile/all.T - + testsuite/tests/th/T26098A_quote.hs - + testsuite/tests/th/T26098A_splice.hs - + testsuite/tests/th/T26098_local.hs - + testsuite/tests/th/T26098_local.stderr - + testsuite/tests/th/T26098_quote.hs - + testsuite/tests/th/T26098_quote.stderr - + testsuite/tests/th/T26098_splice.hs - + testsuite/tests/th/T26098_splice.stderr - testsuite/tests/th/all.T - testsuite/tests/warnings/should_fail/CaretDiagnostics1.stderr - utils/check-exact/ExactPrint.hs - utils/haddock/haddock-api/src/Haddock/Backends/Hoogle.hs - utils/haddock/haddock-api/src/Haddock/Convert.hs - utils/haddock/haddock-api/src/Haddock/Interface/Rename.hs - utils/haddock/haddock-api/src/Haddock/Types.hs The diff was not included because it is too large. View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/1a6aff80251aeb5d31c46ad62d5b9b… -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/1a6aff80251aeb5d31c46ad62d5b9b… You're receiving this email because of your account on gitlab.haskell.org.

1 0

[Git][ghc/ghc][wip/int-index/drop-tylit] WIP: Drop HsTyLit in favor of HsLit
by Vladislav Zavialov (＠int-index) 03 Feb '26

03 Feb '26

Vladislav Zavialov pushed to branch wip/int-index/drop-tylit at Glasgow Haskell Compiler / GHC Commits: 305780e8 by Vladislav Zavialov at 2026-02-04T01:07:04+03:00 WIP: Drop HsTyLit in favor of HsLit - - - - - 47 changed files: - compiler/GHC/Hs/Instances.hs - compiler/GHC/Hs/Lit.hs - compiler/GHC/Hs/Syn/Type.hs - compiler/GHC/Hs/Type.hs - compiler/GHC/HsToCore/Errors/Ppr.hs - compiler/GHC/HsToCore/Errors/Types.hs - compiler/GHC/HsToCore/Match/Literal.hs - compiler/GHC/HsToCore/Quote.hs - compiler/GHC/Parser.y - compiler/GHC/Parser/PostProcess.hs - compiler/GHC/Rename/Expr.hs - compiler/GHC/Rename/HsType.hs - compiler/GHC/Rename/Pat.hs - compiler/GHC/Rename/Utils.hs - compiler/GHC/Tc/Errors/Ppr.hs - compiler/GHC/Tc/Errors/Types.hs - compiler/GHC/Tc/Gen/App.hs - compiler/GHC/Tc/Gen/HsType.hs - compiler/GHC/Tc/Gen/Pat.hs - compiler/GHC/ThToHs.hs - compiler/GHC/Types/Error/Codes.hs - compiler/GHC/Types/SourceText.hs - compiler/Language/Haskell/Syntax/Expr.hs - compiler/Language/Haskell/Syntax/Extension.hs - compiler/Language/Haskell/Syntax/Lit.hs - compiler/Language/Haskell/Syntax/Type.hs - libraries/ghc-internal/src/GHC/Internal/TH/Lib.hs - testsuite/tests/ghc-api/annotations-literals/parsed.hs - + testsuite/tests/th/T26862_th.script - + testsuite/tests/th/T26862_th.stderr - + testsuite/tests/th/T8306_th.script - + testsuite/tests/th/T8306_th.stderr - + testsuite/tests/th/T8306_th.stdout - testsuite/tests/th/T8412.stderr - testsuite/tests/th/all.T - + testsuite/tests/typecheck/should_fail/T26861.hs - + testsuite/tests/typecheck/should_fail/T26861.stderr - + testsuite/tests/typecheck/should_fail/T26862.hs - + testsuite/tests/typecheck/should_fail/T26862.stderr - testsuite/tests/typecheck/should_fail/T8306.stderr - testsuite/tests/typecheck/should_fail/all.T - utils/check-exact/ExactPrint.hs - utils/haddock/haddock-api/src/Haddock/Backends/LaTeX.hs - utils/haddock/haddock-api/src/Haddock/Backends/Xhtml/Decl.hs - utils/haddock/haddock-api/src/Haddock/Convert.hs - utils/haddock/haddock-api/src/Haddock/Interface/Rename.hs - utils/haddock/haddock-api/src/Haddock/Types.hs The diff was not included because it is too large. View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/305780e860d70ee23c5a33d9020a066… -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/305780e860d70ee23c5a33d9020a066… You're receiving this email because of your account on gitlab.haskell.org.

1 0

[Git][ghc/ghc][master] Use Haddock formatting in deprecation message of `initNameCache`
by Marge Bot (＠marge-bot) 03 Feb '26

03 Feb '26

Marge Bot pushed to branch master at Glasgow Haskell Compiler / GHC Commits: 5f0dbeb6 by Simon Hengel at 2026-02-03T16:00:12-05:00 Use Haddock formatting in deprecation message of `initNameCache` - - - - - 1 changed file: - compiler/GHC/Types/Name/Cache.hs Changes: ===================================== compiler/GHC/Types/Name/Cache.hs ===================================== @@ -162,9 +162,7 @@ newNameCacheWith ut nc = NameCache (uniqueTag ut) <$> newMVar nc -- | This takes a tag for uniques to be generated and the list of knownKeyNames -- These must be initialized properly to ensure that names generated from this -- NameCache do not conflict with known key names. --- --- Use `newNameCache` or `newNameCacheWith` instead -{-# DEPRECATED initNameCache "Use newNameCache or newNameCacheWith instead" #-} +{-# DEPRECATED initNameCache "Use `newNameCache` or `newNameCacheWith` instead" #-} initNameCache :: UniqueTag -> [Name] -> IO NameCache initNameCache c names = newNameCacheWith c (initOrigNames names) View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/5f0dbeb631c9582b40f3e0b05333219… -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/5f0dbeb631c9582b40f3e0b05333219… You're receiving this email because of your account on gitlab.haskell.org.

1 0

[Git][ghc/ghc][master] ExplicitLevelImports: check staging for types just like for values
by Marge Bot (＠marge-bot) 03 Feb '26

03 Feb '26

Marge Bot pushed to branch master at Glasgow Haskell Compiler / GHC Commits: c64cca1e by mangoiv at 2026-02-03T15:59:29-05:00 ExplicitLevelImports: check staging for types just like for values Previously, imported types were entirely exempted from staging checks as the implicit stage persistance assumed to be all imported types to be well staged. ExplicitLevelImports' change specification, however, does not do such an exemption. Thus we want to introduce such a check, just like we have for values. ExplicitLevelImports does not, however, talk about local names - from its perspective, we could theoretically keep treating locally introduced types specially - e.g. an ill-staged used in a quote would only emit a warning, not an error. To allow for a potential future migration away from such wrinkles as the staging check in notFound (see Note [Out of scope might be a staging error]) we consistently do the strict staging check that we also do for value if ExplicitLevelImports is on. Closes #26098 - - - - - 11 changed files: - compiler/GHC/Rename/HsType.hs - compiler/GHC/Rename/Splice.hs-boot - + testsuite/tests/th/T26098A_quote.hs - + testsuite/tests/th/T26098A_splice.hs - + testsuite/tests/th/T26098_local.hs - + testsuite/tests/th/T26098_local.stderr - + testsuite/tests/th/T26098_quote.hs - + testsuite/tests/th/T26098_quote.stderr - + testsuite/tests/th/T26098_splice.hs - + testsuite/tests/th/T26098_splice.stderr - testsuite/tests/th/all.T Changes: ===================================== compiler/GHC/Rename/HsType.hs ===================================== @@ -1,4 +1,5 @@ {-# LANGUAGE TypeFamilies #-} +{-# LANGUAGE MultiWayIf #-} {- (c) The GRASP/AQUA Project, Glasgow University, 1992-1998 @@ -42,7 +43,7 @@ module GHC.Rename.HsType ( import GHC.Prelude -import {-# SOURCE #-} GHC.Rename.Splice( rnSpliceType, checkThLocalTyName ) +import {-# SOURCE #-} GHC.Rename.Splice( rnSpliceType, checkThLocalTyName, checkThLocalNameNoLift ) import GHC.Core.TyCo.FVs ( tyCoVarsOfTypeList ) import GHC.Core.TyCon ( isKindName ) @@ -537,10 +538,18 @@ rnHsTyKi env tv@(HsTyVar _ ip (L loc rdr_name)) -- of PolyKinds (see #14710) ; name <- rnTyVar env rdr_name ; this_mod <- getModule - ; when (nameIsLocalOrFrom this_mod name) $ - checkThLocalTyName name + ; explicit_level_imports <- xoptM LangExt.ExplicitLevelImports + ; let loc_name_with_rdr = L loc $ WithUserRdr rdr_name name + ; if | explicit_level_imports + -- See Note [Strict level checks with ExplicitLevelImports] + -> checkThLocalNameNoLift loc_name_with_rdr + + | nameIsLocalOrFrom this_mod name + -> checkThLocalTyName name + + | otherwise -> pure () ; checkPromotedDataConName env tv Prefix ip name - ; return (HsTyVar noAnn ip (L loc $ WithUserRdr rdr_name name), unitFV name) } + ; return (HsTyVar noAnn ip loc_name_with_rdr, unitFV name) } rnHsTyKi env ty@(HsOpTy _ prom ty1 l_op ty2) = setSrcSpan (getLocA l_op) $ @@ -685,6 +694,37 @@ rnHsTyLit tyLit@(HsNumTy x i) = do pure (HsNumTy x i) rnHsTyLit (HsCharTy x c) = pure (HsCharTy x c) +{- +Note [Strict level checks with ExplicitLevelImports] +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +Since the proposed change specification of `ExplicitLevelImports` [1] talks about +all identifiers as if they were created equally in the context of TemplateHaskell, +we want to adhere to that specification and at the same time use this unique +chance of being able to guard the "correct" behaviour behind an extension, without +breaking too many users. That is why, if ExplicitLevelImports is on, we +- do not allow non-well-levelled types to be imported +- do not allow locally defined type names to be used in an ill-levelled way, more + most importantly, we do not allow locally defined names to be used in quotes. + +When doing level checks, we historically have been glancing over some +not-well-levelled programs - e.g. the following program was historically +accepted from the perspective of the stage restriction: + +type T = ExpQ +x = $(_ :: T) + +However, when type-checking the splice `$(_ :: T)`, we found that `T` +had not yet been made part of the type-checking environment - we would +insert an ad-hoc check in `notFound` which would report the staging error. + +See Note [Out of scope might be a staging error] + +This is obviously not very rigorous - our "specification" of a program +being well-staged becomes "if the type checker needs the thing to be in scope +and it is not, the program is not well-staged, otherwise it is". + +[1]: https://github.com/ghc-proposals/ghc-proposals/blob/8e4d0e9340c04b904373f9d… +-} rnHsMultAnnWith :: (LocatedA (mult GhcPs) -> RnM (LocatedA (mult GhcRn), FreeVars)) -> HsMultAnnOf (LocatedA (mult GhcPs)) GhcPs ===================================== compiler/GHC/Rename/Splice.hs-boot ===================================== @@ -16,3 +16,5 @@ rnSpliceDecl :: SpliceDecl GhcPs -> RnM (SpliceDecl GhcRn, FreeVars) rnTopSpliceDecls :: HsUntypedSplice GhcPs -> RnM ([LHsDecl GhcPs], FreeVars) checkThLocalTyName :: Name -> RnM () + +checkThLocalNameNoLift :: LIdOccP GhcRn -> RnM () ===================================== testsuite/tests/th/T26098A_quote.hs ===================================== @@ -0,0 +1,4 @@ +module T26098A_quote where + +data T = MkT + ===================================== testsuite/tests/th/T26098A_splice.hs ===================================== @@ -0,0 +1,7 @@ +module T26098A_splice where + +import Language.Haskell.TH + +data T = MkT + +type Foo = ExpQ ===================================== testsuite/tests/th/T26098_local.hs ===================================== @@ -0,0 +1,32 @@ +{-# LANGUAGE ExplicitLevelImports #-} +module T26098_local where + +import Language.Haskell.TH +import Data.Char +import Data.Proxy + +tardy :: forall a. Proxy a -> IO Type +tardy _ = [t| a |] + +tardy2 :: forall a. Proxy a -> IO Exp +tardy2 _ = [| id @a |] + +tardy3 :: forall a. Proxy a -> Code IO (a -> a) +tardy3 _ = [|| id @a ||] + +main :: IO () +main = do + tardy (Proxy @Int) >>= putStrLn . filt . show + tardy2 (Proxy @Int) >>= putStrLn . filt . show + examineCode (tardy3 (Proxy @Int)) >>= putStrLn . filt . show . unType + +-- ad-hoc filter uniques, a_12313 -> a +filt :: String -> String +filt = go where + go [] = [] + go ('_' : rest) = go (dropWhile isDigit rest) + go (c:cs) = c : go cs + +type T = ExpQ + +blup = $(3 :: T) ===================================== testsuite/tests/th/T26098_local.stderr ===================================== @@ -0,0 +1,16 @@ +T26098_local.hs:9:15: error: [GHC-28914] + • Level error: ‘a’ is bound at level 0 but used at level 1 + • In the Template Haskell quotation: [t| a |] + +T26098_local.hs:12:19: error: [GHC-28914] + • Level error: ‘a’ is bound at level 0 but used at level 1 + • In the Template Haskell quotation: [| id @a |] + +T26098_local.hs:15:20: error: [GHC-28914] + • Level error: ‘a’ is bound at level 0 but used at level 1 + • In the Template Haskell typed quotation: [|| id @a ||] + +T26098_local.hs:32:15: error: [GHC-28914] + • Level error: ‘T’ is bound at level 0 but used at level -1 + • In the untyped splice: $(3 :: T) + ===================================== testsuite/tests/th/T26098_quote.hs ===================================== @@ -0,0 +1,12 @@ +{-# LANGUAGE ExplicitLevelImports, DataKinds, TemplateHaskell #-} +module T26098_quote where + +import splice T26098A_quote +import T26098A_quote +import Language.Haskell.TH + +c :: Q Type +c = [t|T|] + +d :: Q Type +d = [t|'MkT|] ===================================== testsuite/tests/th/T26098_quote.stderr ===================================== @@ -0,0 +1,14 @@ +T26098_quote.hs:9:8: error: [GHC-28914] + • Level error: ‘T’ is bound at levels {-1, 0} but used at level 1 + • Available from the imports: + • imported from ‘T26098A_quote’ at T26098_quote.hs:5:1-20 + • imported from ‘T26098A_quote’ at -1 at T26098_quote.hs:4:1-27 + • In the Template Haskell quotation: [t| T |] + +T26098_quote.hs:12:8: error: [GHC-28914] + • Level error: ‘MkT’ is bound at levels {-1, 0} but used at level 1 + • Available from the imports: + • imported from ‘T26098A_quote’ at T26098_quote.hs:5:1-20 + • imported from ‘T26098A_quote’ at -1 at T26098_quote.hs:4:1-27 + • In the Template Haskell quotation: [t| 'MkT |] + ===================================== testsuite/tests/th/T26098_splice.hs ===================================== @@ -0,0 +1,9 @@ +{-# LANGUAGE ExplicitLevelImports, TemplateHaskell #-} +module T26098_splice where + +import T26098A_splice +import quote T26098A_splice + +import splice Prelude + +x = $(undefined :: Foo) ===================================== testsuite/tests/th/T26098_splice.stderr ===================================== @@ -0,0 +1,7 @@ +T26098_splice.hs:9:20: error: [GHC-28914] + • Level error: ‘Foo’ is bound at levels {0, 1} but used at level -1 + • Available from the imports: + • imported from ‘T26098A_splice’ at 1 at T26098_splice.hs:5:1-27 + • imported from ‘T26098A_splice’ at T26098_splice.hs:4:1-21 + • In the untyped splice: $(undefined :: Foo) + ===================================== testsuite/tests/th/all.T ===================================== @@ -624,6 +624,9 @@ test('T24997', normal, compile_and_run, ['']) test('T25256', normal, compile_and_run, ['']) test('T24572a', normal, compile, ['']) test('T24572b', normal, compile_fail, ['']) +test('T26098_splice', [extra_files(['T26098A_splice.hs'])], multimod_compile_fail, ['T26098_splice', '-v0 ' + config.ghc_th_way_flags]) +test('T26098_quote', [extra_files(['T26098A_quote.hs'])], multimod_compile_fail, ['T26098_quote', '-v0 ' + config.ghc_th_way_flags]) +test('T26098_local', normal, compile_fail, ['']) test('T24572c', normal, compile_fail, ['']) test('T26568', normal, compile_fail, ['']) test('T24572d', normal, compile, ['']) View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/c64cca1ef667751c02ce2eb4141349e… -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/c64cca1ef667751c02ce2eb4141349e… You're receiving this email because of your account on gitlab.haskell.org.

1 0