redefinition of 'GC' as different kind of symbol, on Linux

[funatsufumiya]

Issue Description

Symbol GC is predefined in jank, so cannot include /usr/include/X11/Xlib.h on Linux/Ubuntu

In file included from <<< inputs >>>:1:
In file included from input_line_2:12:
In file included from include/sokol_app.h:2527:
/usr/include/X11/Xlib.h:222:2: error: redefinition of 'GC' as different kind of symbol
  222 | *GC;
      |  ^
/usr/local/bin/../lib/jank/0.1/bin/../include/gc/gc_cpp.h:250:3: note: previous definition is here
  250 |   GC = UseGC,
      |   ^
In file included from <<< inputs >>>:1:
In file included from input_line_2:12:
In file included from include/sokol_app.h:2527:
/usr/include/X11/Xlib.h:267:2: error: unknown type name 'GC'
  267 |         GC default_gc;          /* GC for the root root visual */
  
  ...
  

Reproduction Steps

For example #include <sokol_app.h> of sokol, in jank

jank health check

─ system ───────────────────────────────────────────────────────────────────────────────────────────
─ ✅ operating system: linux
─ ✅ default triple: x86_64-unknown-linux-gnu

─ jank install ─────────────────────────────────────────────────────────────────────────────────────
─ ✅ jank version: jank-0.1-alpha
─ ✅ jank resource dir: ../lib/jank/0.1
─ ✅ jank resolved resource dir: /usr/local/bin/../lib/jank/0.1 (found)
─ ✅ jank user cache dir: /home/funatsu/.cache/jank/x86_64-unknown-linux-gnu-3f3f53385c890ae1047dabebf6a51d50696c54bc3f3672891e0b3c861b84a2fd (found)

─ clang install ────────────────────────────────────────────────────────────────────────────────────
─ ⚠️  configured clang path: /home/runner/work/jank/jank/compiler+runtime/build/llvm-install/usr/local/bin/clang++ (not found)
─ ✅ runtime clang path: /usr/local/bin/../lib/jank/0.1/bin/clang++ (found)
─ ⚠️  configured clang resource dir: /home/runner/work/jank/jank/compiler+runtime/build/llvm-install/usr/local/lib/clang/22 (not found)
─ ✅ runtime clang resource dir: /usr/local/lib/jank/0.1/lib/clang/22 (found)

─ jank runtime ─────────────────────────────────────────────────────────────────────────────────────
─ ✅ jank runtime initialized
─ ✅ jank pch path: /home/funatsu/.cache/jank/x86_64-unknown-linux-gnu-3f3f53385c890ae1047dabebf6a51d50696c54bc3f3672891e0b3c861b84a2fd (found)
─ ✅ jank can jit compile c++
─ ✅ jank can aot compile working binaries

─ support ──────────────────────────────────────────────────────────────────────────────────────────
If you're having issues with jank, please either ask the jank community on the Clojurians Slack or report the issue on Github.

─ Slack: https://clojurians.slack.com/archives/C03SRH97FDK
─ Github: https://github.com/jank-lang/jank

Stack trace

No response

OS Version Information

Ubuntu 24.04

I acknowledge that:

• I have searched the jank repository (both open and closed Discussions and Issues) and confirm this is not a duplicate of an existing issue or discussion.
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[jeaye]

Ah, that's an unfortunate C naming collision. Does this help you? https://github.com/bdwgc/bdwgc/blob/master/include/gc/gc_cpp.h#L249

It could be that jank needs to use that internally, in the PCH, etc. But maybe you can get away with defining it yourself?

If you try to define this and still can't compile, I'm open to defining it in jank and then updating our usages of GC to be UseGC. If you want to make a PR for that, even better.

[funatsufumiya]

@jeaye
I created a fork, feature branch for this.
https://github.com/funatsufumiya/jank/tree/feat/gc_name_conflict

If it's a normal fork, I'll create PR now, but this includes submodule update (bdwgc) pointing my feature branch:
https://github.com/funatsufumiya/bdwgc/tree/feat/gc_name_conflict

So I don't know how to create PR from this.

FYI, this fork solved the problem. Also ./bin/test passed.

$ jank repl
user=> (cpp/raw "#include <X11/Xlib.h>")
nil

$ ./bin/test
tested 756 jank files with 8 skips and 0 failures
===============================================================================
[doctest] test cases:  119 |  119 passed | 0 failed | 0 skipped
[doctest] assertions: 1899 | 1899 passed | 0 failed |
[doctest] Status: SUCCESS!

[jeaye]

Nice work! We should not be making changes to bdwgc for this. The jank changes look good, but we need to define GC_NAME_CONFLICT in jank's CMakeLists.txt so that bdwgc will not use GC. There is no need to comment it out, since bdwgc already has a #ifndef there. We should add -DGC_NAME_CONFLICT on this line: https://github.com/jank-lang/jank/blob/main/compiler%2Bruntime/CMakeLists.txt#L106

[funatsufumiya]

OK! I'll fix it.

[funatsufumiya]

@jeaye
Fixed. I'll create PR.
https://github.com/funatsufumiya/jank/tree/feat/gc_name_conflict

[funatsufumiya]

Created.
#721