Fix definition of _Py_RemoteDebug_ symbols for static linking

[zanieb]

As noted at

cpython/Python/remote_debug.h

Line 9 in 01bb53d

If you need to add a new function ensure that is declared 'static'.

it's critical that these definitions are static. Otherwise, statically linking the module will fail (as I encountered downstream in python-build-standalone), e.g.:

cpython-3.14> ld64.lld: error: duplicate symbol: _Py_RemoteDebug_ClearCache
cpython-3.14> >>> defined in remote_debug.h:125 (Python/remote_debug.h:125)
cpython-3.14> >>>            Python/remote_debugging.o
cpython-3.14> >>> defined in remote_debug.h:125 (./Modules/../Python/remote_debug.h:125)
cpython-3.14> >>>            Modules/_remote_debugging_module.o

[zanieb]

I'm happy to include a news entry and issue if desired, we chatted about this problem briefly in Discord and I figured I'd just quickly post the patch.

[zanieb]

CI has some compiler warnings

Run python3 Tools/build/check_warnings.py --compiler-output-file-path=compiler_output_macos.txt --warning-ignore-file-path=Tools/build/.warningignore_macos --compiler-output-type=clang --fail-on-regression --fail-on-improvement --path-prefix="./"
Unexpected warnings:
Python/remote_debug.h expected 0 warnings, found 2
{'file': 'Python/remote_debug.h', 'line': '[13](https://github.com/python/cpython/actions/runs/15448318268/job/43483840500?pr=135146#step:10:14)5', 'column': '1', 'message': "unused function '_Py_RemoteDebug_ClearCache'", 'option': '-Wunused-function'}
{'file': 'Python/remote_debug.h', 'line': '993', 'column': '1', 'message': "unused function '_Py_RemoteDebug_PagedReadRemoteMemory'", 'option': '-Wunused-function'}

[pablogsal]

Yeah this file is included in two places but they don't use all the functions. We must silence these warnings because they are false positives

[pablogsal]

I'm happy to include a news entry and issue if desired, we chatted about this problem briefly in Discord and I figured I'd just quickly post the patch.

No need. This is not a user visible change and it doesn't really qualify as a bug fix (depends how you look at it). I am happy either way basically

[zanieb]

@pablogsal I've silenced the warnings.

[pablogsal]

Hummm, I still see the warnings in GitHub in the https://github.com/python/cpython/pull/135146/files page. Is this expected?

[zanieb]

Yeah I think so? I'm not familiar with the warnings tooling, but I believe I've just followed the "standard" way to silence new warnings in a file. If there's another way, we'll need to hear from someone who's an owner of such things :)

[pablogsal]

Maybe set this:

#ifdef __clang__
    #define UNUSED __attribute__((unused))
#elif defined(__GNUC__)
    #define UNUSED __attribute__((unused))
#elif defined(_MSC_VER)
    #define UNUSED __pragma(warning(suppress: 4505))
#else
    #define UNUSED
#endif

UNUSED static void my_function(void) {
    // Function body
}

[chris-eibl]

Yeah, as @pablogsal suggests, I'd use diagnostic pragmas to silence these warnings (because MSVC does not feature __attribute__((unused)) AFAIK). There is already infrastructure for that in

cpython/Include/pyport.h

Lines 297 to 302 in c740fe3

	#if defined(__clang__)
	#define _Py_COMP_DIAG_PUSH _Pragma("clang diagnostic push")
	#define _Py_COMP_DIAG_IGNORE_DEPR_DECLS \
	_Pragma("clang diagnostic ignored \"-Wdeprecated-declarations\"")
	#define _Py_COMP_DIAG_POP _Pragma("clang diagnostic pop")
	#elif defined(__GNUC__) \

which might be suitable to use / extend.

I'd furthermore suggest to enable the warnings again using _Py_COMP_DIAG_POP to limit the scope of the supressions.

[chris-eibl]

On a second thought please scratch my suggestion above. If using

#define UNUSED __pragma(warning(suppress: 4505))

works like @pablogsal suggested above, then we're fine, since suppress

Pushes the current state of the pragma on the stack, disables the specified warning for the next line, and then pops the warning stack so that the pragma state is reset

Sorry for the noise.

[zanieb]

That seems to have worked fine, thanks!

[miss-islington-app]

Thanks @zanieb for the PR, and @pablogsal for merging it 🌮🎉.. I'm working now to backport this PR to: 3.14.
🐍🍒⛏🤖

[pablogsal]

Awesome, thank you very much @zanieb and @chris-eibl !

[bedevere-app]

GH-135318 is a backport of this pull request to the 3.14 branch.