Apoorv Ingle pushed to branch wip/spj-apporv-Oct24 at Glasgow Haskell Compiler / GHC

Commits:

• 343c8625
  by Apoorv Ingle at 2025-11-27T12:29:15-06:00

  - make sure landmark error contexts are always printed. accept some testcases
  - fix overloaded list error message. Expanded Expressions head `listFromN` should be wrapped in a generated source span
    (Wrinkle) This may make some HIE tests to fail, but HIE should fix the behaviour there.
  - Fix notes
  - fix for MonadFailErrors test case. OrigPat now also stores the statement to make the error message resonable
  

• ba7b32f3
  by Apoorv Ingle at 2025-11-27T12:31:07-06:00

  - `getDeepSubsumptionFlag_DataConHead` performs a non-trivial traversal if the expression passed to it is complex.
    This traversal is necessary if the head of the function is an `XExpr` and `splitHsApps` does not look through them
  - The deepsubsumption flag is stored in EVAlArgQL to reduce the need to call `getDeepSubsumptionFlag_DataConHead`
  - refactor building CtOrigin before instantiations as a function. It does state lookup only if needed.
  - In tcDoStmts, we lose the location of the first statement. It is needed for getting the pattern match check right
    Further, do not call addErrCtxt on it, the tcMonoLExpr will do it for us.
  - during QL arg's function head instantiation use more a more accurate location for arg when the application chain is null
  

35 changed files:

• compiler/GHC/CmmToAsm.hs
• compiler/GHC/Driver/Downsweep.hs
• compiler/GHC/Hs.hs
• compiler/GHC/Hs/Expr.hs
• compiler/GHC/HsToCore/Expr.hs
• compiler/GHC/Iface/Ext/Ast.hs
• compiler/GHC/Rename/Expr.hs
• compiler/GHC/Tc/Errors/Ppr.hs
• compiler/GHC/Tc/Gen/App.hs
• compiler/GHC/Tc/Gen/Do.hs
• compiler/GHC/Tc/Gen/Expr.hs
• compiler/GHC/Tc/Gen/Head.hs
• compiler/GHC/Tc/Gen/Match.hs
• compiler/GHC/Tc/Types/ErrCtxt.hs
• compiler/GHC/Tc/Types/LclEnv.hs
• compiler/GHC/Tc/Types/Origin.hs
• compiler/GHC/Tc/Utils/Monad.hs
• compiler/GHC/Tc/Utils/Unify.hs
• − testsuite/tests/deSugar/should_compile/T10662
• testsuite/tests/default/default-fail05.stderr
• − testsuite/tests/ghci.debugger/Do
• − testsuite/tests/ghci.debugger/Do.hs
• − testsuite/tests/ghci.debugger/T25996.hs
• testsuite/tests/indexed-types/should_fail/T1897b.stderr
• testsuite/tests/parser/should_fail/RecordDotSyntaxFail11.stderr
• testsuite/tests/polykinds/T13393.stderr
• + testsuite/tests/typecheck/should_compile/ExpansionQLIm.hs
• testsuite/tests/typecheck/should_compile/T14590.stderr
• − testsuite/tests/typecheck/should_compile/T25996.hs
• testsuite/tests/typecheck/should_compile/all.T
• − testsuite/tests/typecheck/should_fail/T25970.hs
• − testsuite/tests/typecheck/should_fail/T25996.hs
• testsuite/tests/typecheck/should_fail/T6069.stderr
• testsuite/tests/typecheck/should_fail/T7857.stderr
• testsuite/tests/typecheck/should_fail/tcfail181.stderr

The diff was not included because it is too large.