Hello everyone!
While compiling various software packages for Cygwin i notice that very often
i have to add something like #define _GNU_SOURCE to
them in order to compile correctly. Meanwhile on Linux they compile with no
problems at all. I've narrowed it down to -std=???
option using a simple test case:
--- cut test.cpp ---
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
int main(void)
{
char *p = strdup("hello");
printf("%s\n", p);
free(p);
return 0;
}
--- cut test.cpp ---
$ g++ test.cpp -o test - compiles OK
$ g++ test.cpp -o test -std=c++14 - error: 'strdup' was not declared in this
scope; did you mean 'strcmp'?
By printing out predefined macros (-dM -E) i found out that -std=something
option adds " #define __STRICT_ANSI__ 1" to builtin
macros, but removes all *_SOURCE definitions, so _DEFAULT_SOURCE is not
triggered any more.
I've compared the behavior with Linux system. On Linux -std=c++14 also defines
__STRICT_ANSI__, but various *_SOURCE macros are not
omitted.
Isn't this a Cygwin bug? By the way, clang does not suffer from this problem.
Kind regards,
Pavel Fedin
Senior Engineer
Samsung Electronics Research center Russia
--
Problem reports: https://cygwin.com/problems.html
FAQ: https://cygwin.com/faq/
Documentation: https://cygwin.com/docs.html
Unsubscribe info: https://cygwin.com/ml/#unsubscribe-simple
