[X86] Uninitialized variable warnings in immintrin.h - static analyzer - __builtin_ia32_rdsspd / __builtin_ia32_rdsspq

[buscher]

Kind of related to #55224 , but for the static analyzer.

For the code

#include <x86intrin.h>

int main() {
    return 0;
}

when I execute:

scan-build -analyze-headers cc main.c

I get:

scan-build: Using '/usr/lib/llvm-20/bin/clang' for static analysis
In file included from main.c:2:
In file included from /usr/lib/llvm-20/lib/clang/20/include/x86intrin.h:15:
In file included from /usr/lib/llvm-20/lib/clang/20/include/immintrin.h:577:
/usr/lib/llvm-20/lib/clang/20/include/cetintrin.h:49:10: warning: 1st function call argument is an uninitialized value [core.CallAndMessage]
   49 |   return __builtin_ia32_rdsspd(t);
      |          ^~~~~~~~~~~~~~~~~~~~~~~~
/usr/lib/llvm-20/lib/clang/20/include/cetintrin.h:62:10: warning: 1st function call argument is an uninitialized value [core.CallAndMessage]
   62 |   return __builtin_ia32_rdsspq(t);
      |          ^~~~~~~~~~~~~~~~~~~~~~~~
2 warnings generated.

Happens with llvm/clang 14 and 20, did not test other versions.

[phoebewang]

The definitions are already using #pragma clang diagnostic ignored "-Wuninitialized" to suppress uninitialized warnings. Can the static analyzer recognize the pragma and skip them?