warn_unused_result attribute works in C++ but not C?

nemequ

I just noticed that sunCC in 12.6 supports the warn_unused_result attribute (yay!), but not suncc. It seems like an odd restriction; is it intentional?

Quick test case:

__attribute__((__warn_unused_result__))

int test_unused_result(void) {

  return 1729;

}

int main(int argc, char* argv[]) {

  (void) argc;

  (void) argv;

  test_unused_result();

  if (test_unused_result() != 1729)

    return EXIT_FAILURE;

  return EXIT_SUCCESS;

}

Maxim Kartashev-Oracle

Front-ends of all three Studio compilers (CC, cc and f90) are totally separate, so while some features such as pragmas, attributes, or compiler options are supported by all compilers, others are not.

The warn_unused_result attribute was implemented in the C++ compiler a couple of years ago because there was a demand for it in a large open-source application. We can log an enhancement request to support this attribute for the C compiler in the next version.

Maxim Kartashev-Oracle

Front-ends of all three Studio compilers (CC, cc and f90) are totally separate, so while some features such as pragmas, attributes, or compiler options are supported by all compilers, others are not.

The warn_unused_result attribute was implemented in the C++ compiler a couple of years ago because there was a demand for it in a large open-source application. We can log an enhancement request to support this attribute for the C compiler in the next version.

nemequ

Please do! It's a great feature; I use it often, though of course I hide it behind a macro so it's not blocking anything.

AFAICT it's undocumented, even in the C++ docs; perhaps you could take care of that, too?

Maxim Kartashev-Oracle

I filed 27604996 - support warn_unused_result attribute.