warmcat/libwebsockets
lib/tls/CMakeLists.txt
:367
CHECK_C_SOURCE_COMPILES("#include <openssl/ssl.h>\nint main(void) { STACK_OF(X509) *c = NULL; SSL_CTX *ctx = NULL; return (int)SSL_CTX_get_extra_chain_certs_only(ctx, &c); }\n" LWS_HAVE_SSL_EXTRA_CHAIN_CERTS)