diff options
Diffstat (limited to 'config/c-compiler.m4')
| -rw-r--r-- | config/c-compiler.m4 | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/config/c-compiler.m4 b/config/c-compiler.m4 index ed26644a488..67323ade124 100644 --- a/config/c-compiler.m4 +++ b/config/c-compiler.m4 @@ -285,10 +285,15 @@ fi])# PGAC_C_BUILTIN_BSWAP64 # ------------------------- # Check if the C compiler understands __builtin_constant_p(), # and define HAVE__BUILTIN_CONSTANT_P if so. +# We need __builtin_constant_p("string literal") to be true, but some older +# compilers don't think that, so test for that case explicitly. AC_DEFUN([PGAC_C_BUILTIN_CONSTANT_P], [AC_CACHE_CHECK(for __builtin_constant_p, pgac_cv__builtin_constant_p, [AC_COMPILE_IFELSE([AC_LANG_SOURCE( -[[static int x; static int y[__builtin_constant_p(x) ? x : 1];]] +[[static int x; + static int y[__builtin_constant_p(x) ? x : 1]; + static int z[__builtin_constant_p("string literal") ? 1 : x]; +]] )], [pgac_cv__builtin_constant_p=yes], [pgac_cv__builtin_constant_p=no])]) |