GitLab

Alan Zimmerman pushed to branch wip/az/ghc-cpp at Glasgow Haskell Compiler / GHC

Commits:

6e67fa08

by Ben Gamari at 2025-05-08T06:21:21-04:00

llvmGen: Fix built-in variable predicate

Previously the predicate to identify LLVM builtin global variables was
checking for `$llvm` rather than `@llvm` as it should.

a9d0a22c

by Ben Gamari at 2025-05-08T06:21:22-04:00

llvmGen: Fix linkage of built-in arrays

LLVM now insists that built-in arrays use Appending linkage, not
Internal.

Fixes #25769.

9c6d2b1b

by sheaf at 2025-05-08T06:22:11-04:00

Use mkTrAppChecked in ds_ev_typeable

This change avoids violating the invariant of mkTrApp according to which
the argument should not be a fully saturated function type.
This ensures we don't return false negatives for type equality
involving function types.

Fixes #25998

75cadf81

by Ryan Hendrickson at 2025-05-08T06:22:55-04:00

haddock: Preserve indentation in multiline examples

Intended for use with :{ :}, but doesn't look for those characters. Any
consecutive lines with birdtracks will only have initial whitespace
stripped up to the column of the first line.

fee9b351

by Cheng Shao at 2025-05-08T06:23:36-04:00

ci: re-enable chrome for wasm ghci browser tests

Currently only firefox is enabled for wasm ghci browser tests, for
some reason testing with chrome works on my machine but gets stuck on
gitlab instance runners. This patch re-enables testing with chrome by
passing `--no-sandbox`, since chrome sandboxing doesn't work in
containers without `--cap-add=SYS_ADMIN`.

282df905

by Vladislav Zavialov at 2025-05-09T03:18:25-04:00

Take subordinate 'type' specifiers into account

This patch fixes multiple bugs (#22581, #25983, #25984, #25991)
in name resolution of subordinate import lists.

Bug #22581
----------
In subordinate import lists, the use of the `type` namespace specifier
used to be ignored. For example, this import statement was incorrectly
accepted:

  import Prelude (Bool(type True))

Now it results in an error message:

  <interactive>:2:17: error: [GHC-51433]
    In the import of ‘Prelude’:
      a data type called ‘Bool’ is exported,
      but its subordinate item ‘True’ is not in the type namespace.

Bug #25983
----------
In subordinate import lists within a `hiding` clause, non-existent
items led to a poor warning message with -Wdodgy-imports. Consider:

  import Prelude hiding (Bool(X))

The warning message for this import statement used to misreport the
cause of the problem:

  <interactive>:3:24: warning: [GHC-56449] [-Wdodgy-imports]
    In the import of ‘Prelude’:
      an item called ‘Bool’ is exported, but it is a type.

Now the warning message is correct:

  <interactive>:2:24: warning: [GHC-10237] [-Wdodgy-imports]
    In the import of ‘Prelude’:
      a data type called ‘Bool’ is exported, but it does not export
      any constructors or record fields called ‘X’.

Bug #25984
----------
In subordinate import lists within a `hiding` clause, non-existent
items resulted in the entire import declaration being discarded.
For example, this program was incorrectly accepted:

  import Prelude hiding (Bool(True,X))
  t = True

Now it results in an error message:

  <interactive>:2:5: error: [GHC-88464]
    Data constructor not in scope: True

Bug #25991
----------
In subordinate import lists, it was not possible to refer to a class
method if there was an associated type of the same name:

  module M_helper where
    class C a b where
      type a # b
      (#) :: a -> b -> ()

  module M where
    import M_helper (C((#)))

This import declaration failed with:

  M.hs:2:28: error: [GHC-10237]
    In the import of ‘M_helper’:
      an item called ‘C’ is exported, but it does not export any children
      (constructors, class methods or field names) called ‘#’.

Now it is accepted.

Summary
-------
The changes required to fix these bugs are almost entirely confined to
GHC.Rename.Names. Other than that, there is a new error constructor
BadImportNonTypeSubordinates with error code [GHC-51433].

Test cases:
  T22581a T22581b T22581c T22581d
  T25983a T25983b T25983c T25983d T25983e T25983f T25983g
  T25984a T25984b
  T25991a T25991b1 T25991b2

51b0ce8f

by Simon Peyton Jones at 2025-05-09T03:19:07-04:00

Slighty improve `dropMisleading`

Fix #26105, by upgrading the (horrible, hacky) `dropMisleading`
function.

This fix makes things a bit better but does not cure the underlying
problem.

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.

008eb3de

by Alan Zimmerman at 2025-05-11T09:30:18+01:00

GHC-CPP: first rough proof of concept

Processes

     #define FOO
     #ifdef FOO
     x = 1
     #endif

Into

    [ITcppIgnored [L loc ITcppDefine]
    ,ITcppIgnored [L loc ITcppIfdef]
    ,ITvarid "x"
    ,ITequal
    ,ITinteger (IL {il_text = SourceText "1", il_neg = False, il_value = 1})
    ,ITcppIgnored [L loc ITcppEndif]
    ,ITeof]

In time, ITcppIgnored will be pushed into a comment

089fecc2

by Alan Zimmerman at 2025-05-11T09:30:18+01:00

Tidy up before re-visiting the continuation mechanic

487bb5dc

by Alan Zimmerman at 2025-05-11T09:30:18+01:00

Switch preprocessor to continuation passing style

Proof of concept, needs tidying up

7edf6c54
by Alan Zimmerman at 2025-05-11T09:30:18+01:00
```
Small cleanup
```
2b817f66
by Alan Zimmerman at 2025-05-11T09:30:18+01:00
```
Get rid of some cruft
```

7872e670

by Alan Zimmerman at 2025-05-11T09:30:18+01:00

Starting to integrate.

Need to get the pragma recognised and set

c9e99ed8

by Alan Zimmerman at 2025-05-11T09:30:18+01:00

Make cppTokens extend to end of line, and process CPP comments

e923893a
by Alan Zimmerman at 2025-05-11T09:30:19+01:00
```
Remove unused ITcppDefined
```

e8953c29

by Alan Zimmerman at 2025-05-11T09:30:19+01:00

Allow spaces between # and keyword for preprocessor directive

03b42120

by Alan Zimmerman at 2025-05-11T09:30:19+01:00

Process CPP continuation lines

They are emited as separate ITcppContinue tokens.
Perhaps the processing should be more like a comment, and keep on
going to the end.
BUT, the last line needs to be slurped as a whole.

3a5d4b5b

by Alan Zimmerman at 2025-05-11T09:30:19+01:00

Accumulate CPP continuations, process when ready

Can be simplified further, we only need one CPP token

c6f6c423

by Alan Zimmerman at 2025-05-11T09:30:19+01:00

Simplify Lexer interface. Only ITcpp

We transfer directive lines through it, then parse them from scratch
in the preprocessor.

2401b5bd

by Alan Zimmerman at 2025-05-11T09:30:19+01:00

Deal with directive on last line, with no trailing \n

30c12a64
by Alan Zimmerman at 2025-05-11T09:30:19+01:00
```
Start parsing and processing the directives
```
c14f5912
by Alan Zimmerman at 2025-05-11T09:30:19+01:00
```
Prepare for processing include files
```

3f2af56b

by Alan Zimmerman at 2025-05-11T09:30:19+01:00

Move PpState into PreProcess

And initParserState, initPragState too

7a4c3be6

by Alan Zimmerman at 2025-05-11T09:30:19+01:00

Process nested include files

Also move PpState out of Lexer.x, so it is easy to evolve it in a ghci
session, loading utils/check-cpp/Main.hs

7e897990
by Alan Zimmerman at 2025-05-11T09:30:19+01:00
```
Split into separate files
```

908fac7f

by Alan Zimmerman at 2025-05-11T09:30:19+01:00

Starting on expression parser.

But it hangs. Time for Text.Parsec.Expr

83fa5e8e

by Alan Zimmerman at 2025-05-11T09:30:19+01:00

Start integrating the ghc-cpp work

From https://github.com/alanz/ghc-cpp

c847b2de
by Alan Zimmerman at 2025-05-11T09:30:19+01:00
```
WIP
```
f80202b0
by Alan Zimmerman at 2025-05-11T09:30:19+01:00
```
Fixup after rebase
```
be64d7f1
by Alan Zimmerman at 2025-05-11T09:30:19+01:00
```
WIP
```
62cf6dc2
by Alan Zimmerman at 2025-05-11T09:30:19+01:00
```
Fixup after rebase, including all tests pass
```
19f94464
by Alan Zimmerman at 2025-05-11T09:30:19+01:00
```
Change pragma usage to GHC_CPP from GhcCPP
```
a4bd0f40
by Alan Zimmerman at 2025-05-11T09:30:19+01:00
```
Some comments
```
f1e37370
by Alan Zimmerman at 2025-05-11T09:30:19+01:00
```
Reformat
```
ecf10594
by Alan Zimmerman at 2025-05-11T09:30:19+01:00
```
Delete unused file
```
ce8f468e
by Alan Zimmerman at 2025-05-11T09:30:19+01:00
```
Rename module Parse to ParsePP
```
ac007250
by Alan Zimmerman at 2025-05-11T09:30:19+01:00
```
Clarify naming in the parser
```

c46af796

by Alan Zimmerman at 2025-05-11T09:30:19+01:00

WIP. Switching to alex/happy to be able to work in-tree

Since Parsec is not available

07bb0700

by Alan Zimmerman at 2025-05-11T09:30:19+01:00

Layering is now correct

- GHC lexer, emits CPP tokens
- accumulated in Preprocessor state
- Lexed by CPP lexer, CPP command extracted, tokens concated with
  spaces (to get rid of token pasting via comments)
- if directive lexed and parsed by CPP lexer/parser, and evaluated

3df296e4

by Alan Zimmerman at 2025-05-11T09:30:19+01:00

First example working

Loading Example1.hs into ghci, getting the right results

```
{-# LANGUAGE GHC_CPP #-}
module Example1 where

y = 3

x =
  "hello"
  "bye now"

foo = putStrLn x
```

385c2888

by Alan Zimmerman at 2025-05-11T09:30:19+01:00

Rebase, and all tests pass except whitespace for generated parser

c1b47276
by Alan Zimmerman at 2025-05-11T09:30:19+01:00
```
More plumbing. Ready for testing tomorrow.
```

4d016ede

by Alan Zimmerman at 2025-05-11T09:30:19+01:00

Proress. Renamed module State from Types

And at first blush it seems to handle preprocessor scopes properly.

a9141ac0

by Alan Zimmerman at 2025-05-11T09:30:19+01:00

Insert basic GHC version macros into parser

__GLASGOW_HASKELL__
__GLASGOW_HASKELL_FULL_VERSION__
__GLASGOW_HASKELL_PATCHLEVEL1__
__GLASGOW_HASKELL_PATCHLEVEL2__

5531f1c4
by Alan Zimmerman at 2025-05-11T09:30:19+01:00
```
Re-sync check-cpp for easy ghci work
```
3cc2bd4e
by Alan Zimmerman at 2025-05-11T09:30:19+01:00
```
Get rid of warnings
```

1be7274c

by Alan Zimmerman at 2025-05-11T09:30:19+01:00

Rework macro processing, in check-cpp

Macros kept at the top level, looked up via name, multiple arity
versions per name can be stored

4d0dc3df

by Alan Zimmerman at 2025-05-11T09:30:19+01:00

WIP. Can crack arguments for #define

Next step it to crack out args in an expansion

c1105237
by Alan Zimmerman at 2025-05-11T09:30:19+01:00
```
WIP on arg parsing.
```
e74078ab
by Alan Zimmerman at 2025-05-11T09:30:19+01:00
```
Progress. Still screwing up nested parens.
```
6f9a9807
by Alan Zimmerman at 2025-05-11T09:30:19+01:00
```
Seems to work, but has redundant code
```
1e1ba894
by Alan Zimmerman at 2025-05-11T09:30:19+01:00
```
Remove redundant code
```
0cc89740
by Alan Zimmerman at 2025-05-11T09:30:19+01:00
```
Reformat
```

99905d3a

by Alan Zimmerman at 2025-05-11T09:30:19+01:00

Expand args, single pass

Still need to repeat until fixpoint

ee280b86
by Alan Zimmerman at 2025-05-11T09:30:19+01:00
```
Fixed point expansion
```
27dc3326
by Alan Zimmerman at 2025-05-11T09:30:19+01:00
```
Sync the playground to compiler
```

3f36e05b

by Alan Zimmerman at 2025-05-11T09:30:19+01:00

Working on dumping the GHC_CPP result

But We need to keep the BufSpan in a comment

31f8acf7

by Alan Zimmerman at 2025-05-11T09:30:19+01:00

Keep BufSpan in queued comments in GHC.Parser.Lexer

9f00bb84

by Alan Zimmerman at 2025-05-11T09:30:19+01:00

Getting close to being able to print the combined tokens

showing what is in and what is out

937f1cad

by Alan Zimmerman at 2025-05-11T09:30:19+01:00

First implementation of dumpGhcCpp.

Example output

First dumps all macros in the state, then the source, showing which
lines are in and which are out

------------------------------

- |#define FOO(A,B) A + B
- |#define FOO(A,B,C) A + B + C
- |#if FOO(1,FOO(3,4)) == 8
- |-- a comment
  |x = 1
- |#else
- |x = 5
- |#endif

c4e42534
by Alan Zimmerman at 2025-05-11T09:30:19+01:00
```
Clean up a bit
```
f00e660f
by Alan Zimmerman at 2025-05-11T09:30:20+01:00
```
Add -ddump-ghc-cpp option and a test based on it
```

c0fb8f3b