have_library: checking for main() in -lc… ——————– yes

“gcc -o conftest -I/usr/include -I/usr/include/ruby/backward -I/usr/include -I. -O2 -g -pipe -Wall -Wp,-D_FORTIFY_SOURCE=2 -fexceptions -fstack-protector-strong –param=ssp-buffer-size=4 -grecord-gcc-switches -m64 -mtune=generic -O0 -Wall -fsigned-char conftest.c -L. -L/usr/lib64 -L. -Wl,-z,relro -fstack-protector -rdynamic -Wl,-export-dynamic -m64 -lruby -lpthread -lrt -ldl -lcrypt -lm -lc” In file included from /usr/include/string.h:25:0,

from /usr/include/ruby/ruby.h:51,
from /usr/include/ruby.h:33,
from conftest.c:1:

/usr/include/features.h:330:4: warning: warning _FORTIFY_SOURCE requires compiling with optimization (-O) [-Wcpp]

#  warning _FORTIFY_SOURCE requires compiling with optimization (-O)
   ^

checked program was:

begin

1: include “ruby.h” 2: 3: int main(int argc, char **argv) 4: { 5: return 0; 6: }

end

“gcc -o conftest -I/usr/include -I/usr/include/ruby/backward -I/usr/include -I. -O2 -g -pipe -Wall -Wp,-D_FORTIFY_SOURCE=2 -fexceptions -fstack-protector-strong –param=ssp-buffer-size=4 -grecord-gcc-switches -m64 -mtune=generic -O0 -Wall -fsigned-char conftest.c -L. -L/usr/lib64 -L. -Wl,-z,relro -fstack-protector -rdynamic -Wl,-export-dynamic -m64 -lruby -lc -lpthread -lrt -ldl -lcrypt -lm -lc” In file included from /usr/include/string.h:25:0,

from /usr/include/ruby/ruby.h:51,
from /usr/include/ruby.h:33,
from conftest.c:1:

/usr/include/features.h:330:4: warning: warning _FORTIFY_SOURCE requires compiling with optimization (-O) [-Wcpp]

#  warning _FORTIFY_SOURCE requires compiling with optimization (-O)
   ^

conftest.c: In function 't': conftest.c:5:57: error: 'main' undeclared (first use in this function)

int t(void) { void ((*volatile p)()); p = (void ((*)()))main; return 0; }
                                                        ^

conftest.c:5:57: note: each undeclared identifier is reported only once for each function it appears in conftest.c:5:32: warning: variable 'p' set but not used [-Wunused-but-set-variable]

int t(void) { void ((*volatile p)()); p = (void ((*)()))main; return 0; }
                               ^

checked program was: /* begin */

1: #include "ruby.h"
2: 
3: /*top*/
4: extern int t(void);
5: int t(void) { void ((*volatile p)()); p = (void ((*)()))main; return 0; }
6: int main(int argc, char **argv)
7: {
8:   if (argc > 1000000) {
9:     printf("%p", &t);

10: } 11: 12: return 0; 13: } /* end */

“gcc -o conftest -I/usr/include -I/usr/include/ruby/backward -I/usr/include -I. -O2 -g -pipe -Wall -Wp,-D_FORTIFY_SOURCE=2 -fexceptions -fstack-protector-strong –param=ssp-buffer-size=4 -grecord-gcc-switches -m64 -mtune=generic -O0 -Wall -fsigned-char conftest.c -L. -L/usr/lib64 -L. -Wl,-z,relro -fstack-protector -rdynamic -Wl,-export-dynamic -m64 -lruby -lc -lpthread -lrt -ldl -lcrypt -lm -lc” In file included from /usr/include/string.h:25:0,

from /usr/include/ruby/ruby.h:51,
from /usr/include/ruby.h:33,
from conftest.c:1:

/usr/include/features.h:330:4: warning: warning _FORTIFY_SOURCE requires compiling with optimization (-O) [-Wcpp]

#  warning _FORTIFY_SOURCE requires compiling with optimization (-O)
   ^

conftest.c: In function 't': conftest.c:5:1: warning: implicit declaration of function 'main' [-Wimplicit-function-declaration]

int t(void) { main(); return 0; }
^

checked program was: /* begin */

1: #include "ruby.h"
2: 
3: /*top*/
4: extern int t(void);
5: int t(void) { main(); return 0; }
6: int main(int argc, char **argv)
7: {
8:   if (argc > 1000000) {
9:     printf("%p", &t);

10: } 11: 12: return 0; 13: } /* end */