Questionable MSVC compatibility break after we always defining begin symbol for a section

[KanRobert]

void bar();

#pragma alloc_text("bar", bar)

void bar() {} 

Clang after #96459

clang --target=x86_64-pc-windows-msvc 

error: symbol 'bar' is already defined

(passed in 18.1 release)

MSVC

bar     SEGMENT
bar     PROC
        ret     0
bar     ENDP
bar     ENDS

https://godbolt.org/z/crEzMzzqj

I am not sure whether putting a function is a section with same name is ill-formed or not. GCC also reports an error at assemble stage

__attribute__ ((section ("bar"))) void bar() {} 

Error: symbol `bar' is already defined

https://godbolt.org/z/he51jdbTG

@MaskRay @aengelke

[MaskRay]

In ELF, redefining section symbol as another symbol will lead to an error:

% cat e.c
[[gnu::section("bar")]]
void bar() {}
% clang -c --target=x86_64 e.c
error: bar changed binding to STB_GLOBAL
error: symbol 'bar' is already defined
2 errors generated.

gas perhaps has the error for a lot of object file formats but somehow not for PE/COFF (used by Windows).
Its PE/COFF port is less polished and ideally an error should be reported.

Clang emits GNU style assembly even for Windows and I believe the reporting an error is a desired behavior, matching ELF and the ideal GNU style PE/COFF assembly.

Do you have a use case in mind that suppressing the #pragma alloc_text("bar", bar) error would be better?

[KanRobert]

Do you have a use case in mind that suppressing the #pragma alloc_text("bar", bar) error would be better?

@MaskRay No. This is more like a man-made test case to me.