[clang] Fixes compile error that double colon operator cannot resolve macro with parentheses. #68618
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it's already accepted in https://reviews.llvm.org/D157297 |
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ping for merge @phoebewang @AaronBallman |
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@AaronBallman is this OK ? |
… macro with parentheses.
Error message:
```
In file included from ../src/amd/addrlib/src/core/addrobject.h:21:
../src/amd/addrlib/src/core/addrcommon.h:343:13: error: expected unqualified-id
out = ::_tzcnt_u32(mask);
^
/usr/lib/llvm-15/lib/clang/15.0.6/include/bmiintrin.h:74:27: note: expanded from macro '_tzcnt_u32'
#define _tzcnt_u32(a) (__tzcnt_u32((a)))
```
This is because both GCC/Clang doesn't support compiling the following code:
```
#ifdef _MSC_VER
#include <intrin.h>
#else
#include <x86intrin.h>
#endif
int f(int a) {
return ::(_tzcnt_u32)(a);
}
```
This is because the return statement expects an expression or braced init list: http://eel.is/c++draft/stmt.jump#general-1 but we really only need to care about the expression form (there's no braces in sight).
Grammatically, the leading :: will parse as a qualified-id because it matches the production for nested-name-specifier: http://eel.is/c++draft/expr.prim.id.qual#nt:qualified-id
That needs to be followed by an unqualified-id (http://eel.is/c++draft/expr.prim.id.unqual#nt:unqualified-id), but the open paren does not match any of the grammar productions, so this is a syntax error.
Closes: llvm#64467
Signed-off-by: Yonggang Luo <[email protected]>
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ping for merge |
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Error message:
This is because both GCC/Clang doesn't support compiling the following code:
This is because the return statement expects an expression or braced init list: http://eel.is/c++draft/stmt.jump#general-1 but we really only need to care about the expression form (there's no braces in sight). Grammatically, the leading :: will parse as a qualified-id because it matches the production for nested-name-specifier: http://eel.is/c++draft/expr.prim.id.qual#nt:qualified-id That needs to be followed by an unqualified-id (http://eel.is/c++draft/expr.prim.id.unqual#nt:unqualified-id), but the open paren does not match any of the grammar productions, so this is a syntax error.
Closes: #64467