While building with a custom build of OpenSSL, I noticed in mkmf.log
that all the feature detection checks are done using a program lacking
an OpenSSL header include. `mkmf` retries using a fallback program when
this fails, but that means all the `have_func` calls compile twice when
compiling once should suffice. Example log without this commit:
have_func: checking for X509_STORE_CTX_get0_cert()... -------------------- yes
DYLD_FALLBACK_LIBRARY_PATH=.:../.. "clang -o conftest ...
conftest.c:14:57: error: use of undeclared identifier 'X509_STORE_CTX_get0_cert'
int t(void) { void ((*volatile p)()); p = (void ((*)()))X509_STORE_CTX_get0_cert; return !p; }
^
1 error generated.
checked program was:
/* begin */
1: #include "ruby.h"
2:
3: /*top*/
4: extern int t(void);
5: int main(int argc, char **argv)
6: {
7: if (argc > 1000000) {
8: int (* volatile tp)(void)=(int (*)(void))&t;
9: printf("%d", (*tp)());
10: }
11:
12: return !!argv[argc];
13: }
14: int t(void) { void ((*volatile p)()); p = (void ((*)()))X509_STORE_CTX_get0_cert; return !p; }
/* end */
DYLD_FALLBACK_LIBRARY_PATH=.:../.. "clang -o conftest ...
checked program was:
/* begin */
1: #include "ruby.h"
2:
3: /*top*/
4: extern int t(void);
5: int main(int argc, char **argv)
6: {
7: if (argc > 1000000) {
8: int (* volatile tp)(void)=(int (*)(void))&t;
9: printf("%d", (*tp)());
10: }
11:
12: return !!argv[argc];
13: }
14: extern void X509_STORE_CTX_get0_cert();
15: int t(void) { X509_STORE_CTX_get0_cert(); return 0; }
/* end */
The second compilation succeeds.
Specify the header for each checked function.
https://github.com/ruby/openssl/commit/34ae7d92d0