GitLab

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

Commits:

e64b3f16

by ARATA Mizuki at 2025-06-17T10:13:42+09:00

MachRegs.h: Don't define NO_ARG_REGS when a XMM register is defined

On i386, MAX_REAL_VANILLA_REG is 1, but MAX_REAL_XMM_REG is 4.
If we define NO_ARG_REGS on i386, programs that use SIMD vectors may segfault.

Closes #25985

A couple of notes on the BROKEN_TESTS field:

* This fixes the segfault from T25062_V16.
* The failure from T22187_run was fixed in an earlier commit (see #25561),
  but BROKEN_TESTS was missed at that time.  Now should be a good time to
  mark it fixed.

3e7c6b4d

by Matthew Pickering at 2025-06-18T15:34:04-04:00

Improve error messages when implicit lifting fails

This patch concerns programs which automatically try to fix level errors
by inserting `Lift`. For example:

```
foo x = [| x |]
~>
foo x = [| $(lift x) |]
```

Before, there were two problems with the message.

1. (#26031), the location of the error was reported as the whole
   quotation.
2. (#26035), the message just mentions there is no Lift instance, but
   gives no indicate why the user program needed a Lift instance in the
   first place.

This problem is especially bad when you disable
`ImplicitStagePersistence`, so you just end up with a confusing "No
instance for" message rather than an error message about levels

This patch fixes both these issues.

Firstly, `PendingRnSplice` differentiates between a user-written splice
and an implicit lift. Then, the Lift instance is precisely requested
with a specific origin in the typechecker. If the instance fails to be
solved, the message is reported using the `TcRnBadlyLevelled`
constructor (like a normal level error).

Fixes #26031, #26035

44b8cee2
by Cheng Shao at 2025-06-18T15:34:46-04:00
```
testsuite: add T26120 marked as broken
```

894a04f3

by Cheng Shao at 2025-06-18T15:34:46-04:00

compiler: fix GHC.SysTools.Ar archive member size writing logic

This patch fixes a long-standing bug in `GHC.SysTools.Ar` that emits
the wrong archive member size in each archive header. It should encode
the exact length of the member payload, excluding any padding byte,
otherwise malformed archive that extracts a broken object with an
extra trailing byte could be created.

Apart from the in-tree `T26120` test, I've also created an out-of-tree
testsuite at https://github.com/TerrorJack/ghc-ar-quickcheck that
contains QuickCheck roundtrip tests for `GHC.SysTools.Ar`. With this
fix, simple roundtrip tests and `writeGNUAr`/GNU `ar` roundtrip test
passes. There might be more bugs lurking in here, but this patch is
still a critical bugfix already.

Fixes #26120 #22586.

Co-authored-by: Codex <codex@openai.com>

f677ab5f

by Lauren Yim at 2025-06-18T15:35:37-04:00

fix some typos in the warnings page in the user guide

b968e1c1

by Rodrigo Mesquita at 2025-06-18T15:36:18-04:00

Add a frozen callstack to throwGhcException

Fixes #25956

a5e0c3a3

by fendor at 2025-06-18T15:36:59-04:00

Update using.rst to advertise full mhu support for GHCi

889b8815

by Alan Zimmerman at 2025-06-18T21:22:34+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

4ebf2101

by Alan Zimmerman at 2025-06-18T21:22:34+01:00

Tidy up before re-visiting the continuation mechanic

f0dd0257

by Alan Zimmerman at 2025-06-18T21:22:34+01:00

Switch preprocessor to continuation passing style

Proof of concept, needs tidying up

604d1a13
by Alan Zimmerman at 2025-06-18T21:22:34+01:00
```
Small cleanup
```
fb58338d
by Alan Zimmerman at 2025-06-18T21:22:34+01:00
```
Get rid of some cruft
```

778123da

by Alan Zimmerman at 2025-06-18T21:22:34+01:00

Starting to integrate.

Need to get the pragma recognised and set

946016da

by Alan Zimmerman at 2025-06-18T21:22:34+01:00

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

c8b03ee1
by Alan Zimmerman at 2025-06-18T21:22:34+01:00
```
Remove unused ITcppDefined
```

1de0f0e3

by Alan Zimmerman at 2025-06-18T21:22:34+01:00

Allow spaces between # and keyword for preprocessor directive

088fcc53

by Alan Zimmerman at 2025-06-18T21:22:34+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.

9fe0f67a

by Alan Zimmerman at 2025-06-18T21:22:34+01:00

Accumulate CPP continuations, process when ready

Can be simplified further, we only need one CPP token

bcb05807

by Alan Zimmerman at 2025-06-18T21:22:34+01:00

Simplify Lexer interface. Only ITcpp

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

18cce45b

by Alan Zimmerman at 2025-06-18T21:22:34+01:00

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

01804178
by Alan Zimmerman at 2025-06-18T21:22:35+01:00
```
Start parsing and processing the directives
```
9369dfeb
by Alan Zimmerman at 2025-06-18T21:22:35+01:00
```
Prepare for processing include files
```

2c498ca4

by Alan Zimmerman at 2025-06-18T21:22:35+01:00

Move PpState into PreProcess

And initParserState, initPragState too

08dc4d62

by Alan Zimmerman at 2025-06-18T21:22:35+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

9b8af447
by Alan Zimmerman at 2025-06-18T21:22:35+01:00
```
Split into separate files
```

462d0b45

by Alan Zimmerman at 2025-06-18T21:22:35+01:00

Starting on expression parser.

But it hangs. Time for Text.Parsec.Expr

9a0bb0ac

by Alan Zimmerman at 2025-06-18T21:22:35+01:00

Start integrating the ghc-cpp work

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

3d703f19
by Alan Zimmerman at 2025-06-18T21:22:35+01:00
```
WIP
```
8c8ab9de
by Alan Zimmerman at 2025-06-18T21:22:35+01:00
```
Fixup after rebase
```
292f6173
by Alan Zimmerman at 2025-06-18T21:22:35+01:00
```
WIP
```
aa1d4f99
by Alan Zimmerman at 2025-06-18T21:22:35+01:00
```
Fixup after rebase, including all tests pass
```
5b20ff87
by Alan Zimmerman at 2025-06-18T21:22:35+01:00
```
Change pragma usage to GHC_CPP from GhcCPP
```
3d2e444d
by Alan Zimmerman at 2025-06-18T21:22:35+01:00
```
Some comments
```
9bbf6ba8
by Alan Zimmerman at 2025-06-18T21:22:35+01:00
```
Reformat
```
f470c7b5
by Alan Zimmerman at 2025-06-18T21:22:35+01:00
```
Delete unused file
```
eff62de5
by Alan Zimmerman at 2025-06-18T21:22:35+01:00
```
Rename module Parse to ParsePP
```
e66be481
by Alan Zimmerman at 2025-06-18T21:22:35+01:00
```
Clarify naming in the parser
```

a0224ad1

by Alan Zimmerman at 2025-06-18T21:22:35+01:00

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

Since Parsec is not available

2cef2273

by Alan Zimmerman at 2025-06-18T21:22:35+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

9878bce6

by Alan Zimmerman at 2025-06-18T21:22:35+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
```

411767d9

by Alan Zimmerman at 2025-06-18T21:22:35+01:00

Rebase, and all tests pass except whitespace for generated parser

2a92b35c
by Alan Zimmerman at 2025-06-18T21:22:35+01:00
```
More plumbing. Ready for testing tomorrow.
```

53d2399c

by Alan Zimmerman at 2025-06-18T21:22:35+01:00

Proress. Renamed module State from Types

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

5703c1a9

by Alan Zimmerman at 2025-06-18T21:22:35+01:00

Insert basic GHC version macros into parser

__GLASGOW_HASKELL__
__GLASGOW_HASKELL_FULL_VERSION__
__GLASGOW_HASKELL_PATCHLEVEL1__
__GLASGOW_HASKELL_PATCHLEVEL2__

914c0931
by Alan Zimmerman at 2025-06-18T21:22:35+01:00
```
Re-sync check-cpp for easy ghci work
```
3f227991
by Alan Zimmerman at 2025-06-18T21:22:35+01:00
```
Get rid of warnings
```

5e878d93

by Alan Zimmerman at 2025-06-18T21:22:35+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

e7bdaaa4

by Alan Zimmerman at 2025-06-18T21:22:35+01:00

WIP. Can crack arguments for #define

Next step it to crack out args in an expansion

373f9916
by Alan Zimmerman at 2025-06-18T21:22:35+01:00
```
WIP on arg parsing.
```
d8d130c5
by Alan Zimmerman at 2025-06-18T21:22:35+01:00
```
Progress. Still screwing up nested parens.
```
0080df4a
by Alan Zimmerman at 2025-06-18T21:22:35+01:00
```
Seems to work, but has redundant code
```
686084ca
by Alan Zimmerman at 2025-06-18T21:22:35+01:00
```
Remove redundant code
```
b378b0e9
by Alan Zimmerman at 2025-06-18T21:22:35+01:00
```
Reformat
```

9be9de1f

by Alan Zimmerman at 2025-06-18T21:22:35+01:00

Expand args, single pass

Still need to repeat until fixpoint

4fe1d38e
by Alan Zimmerman at 2025-06-18T21:22:35+01:00
```
Fixed point expansion
```
2c868e15
by Alan Zimmerman at 2025-06-18T21:22:35+01:00
```
Sync the playground to compiler
```

65e5a420

by Alan Zimmerman at 2025-06-18T21:22:35+01:00

Working on dumping the GHC_CPP result

But We need to keep the BufSpan in a comment

305ffb14

by Alan Zimmerman at 2025-06-18T21:22:35+01:00

Keep BufSpan in queued comments in GHC.Parser.Lexer

54a1c9ff