[ruby/openssl] Check for OpenSSL functions in headers

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

0 files changed, 0 insertions, 0 deletions