I have been trying to make clangd work with my GCC-based builds (it's a
long story don't ask) and after a ton of effort (and, unfortunately,
some hacks due to clangd limitations) there is one thing left that's
causing a lot of spurious errors:
In gcc/libstdc++-v3/include/bits/semaphore_base.h we find:
56 #ifdef SEM_VALUE_MAX
57 static constexpr ptrdiff_t _S_max = SEM_VALUE_MAX;
58 #else
59 static constexpr ptrdiff_t _S_max = _POSIX_SEM_VALUE_MAX;
60 #endif
Unfortunately because I am using limits.h from the clang intrinsics /
resource directory (else many other things break), _POSIX_SEM_VALUE_MAX
is not defined. I can't quite figure out why, and my attempts to
generate preprocessor output to track it down through the #include /
#define maze have failed. But the error I get (from clangd) suggests I
want to be using _SC_SEM_VALUE_MAX and indeed if I make that change it
works.
Should GCC be using the _SC version, since that's what's defined in
POSIX?
Or at least expanding the above to use it as a last resort, as in:
#if defined(SEM_VALUE_MAX)
static constexpr ptrdiff_t _S_max = SEM_VALUE_MAX;
#elif defined(_POSIX_SEM_VALUE_MAX)
static constexpr ptrdiff_t _S_max = _POSIX_SEM_VALUE_MAX;
#else
static constexpr ptrdiff_t _S_max = _SC_SEM_VALUE_MAX;
#endif
??
