compilers: Add prefix before limits.h in has_function checks
prefix might define _GNU_SOURCE, which *must* be defined before your
first include of limits.h, so we must define it first.
There's not really any downsides to including limits.h after the
prefix.
@@ -949,12 +949,13 @@ class CCompiler(Compiler):
"""
# Define the symbol to something else since it is defined by the
# includes or defines listed by the user or by the compiler. This may
- # include, for instance _GNU_SOURCE. Then, undef the symbol to get rid
- # of it completely.
+ # include, for instance _GNU_SOURCE which must be defined before
+ # limits.h, which includes features.h
+ # Then, undef the symbol to get rid of it completely.
head = '''
#define {func} meson_disable_define_of_{func}
- #include <limits.h>
{prefix}
+ #include <limits.h>
#undef {func}
'''
# Override any GCC internal prototype and declare our own definition for
@@ -980,8 +981,9 @@ class CCompiler(Compiler):
user for the function prototype while checking if a function exists.
"""
# Add the 'prefix', aka defines, includes, etc that the user provides
- # This may include, for instance _GNU_SOURCE
- head = '#include <limits.h>\n{prefix}\n'
+ # This may include, for instance _GNU_SOURCE which must be defined
+ # before limits.h, which includes features.h
+ head = '{prefix}\n#include <limits.h>\n'
# We don't know what the function takes or returns, so return it as an int.
# Just taking the address or comparing it to void is not enough because
# compilers are smart enough to optimize it away. The resulting binary
