Give a useful error message if uuid-ossp is built without preconfiguration.

tglsfdc · tglsfdc · commit b86515da1a73 · 2016-12-22T11:19:04.000-05:00
Before commit b8cc8f9, it was possible to build contrib/uuid-ossp without having told configure you meant to; you could just cd into that directory and "make". That no longer works because the code depends on configure to have done header and library probes, but the ensuing error messages are not so easy to interpret if you're not an old C hand. We've gotten a couple of complaints recently from people trying to do this the low-tech way, so add an explicit #error directing the user to use --with-uuid. (In principle we might want to do something similar in the other optionally-built contrib modules; but I don't think any of the others have ever worked without preconfiguration, so there are no bad habits to break people of.) Back-patch to 9.4 where the previous commit came in. Report: https://postgr.es/m/CAHeEsBf42AWTnk=1qJvFv+mYgRFm07Knsfuc86Ono8nRjf3tvQ@mail.gmail.com Report: https://postgr.es/m/CAKYdkBrUaZX+F6KpmzoHqMtiUqCtAW_w6Dgvr6F0WTiopuGxow@mail.gmail.com
diff --git a/contrib/uuid-ossp/uuid-ossp.c b/contrib/uuid-ossp/uuid-ossp.c
@@ -30,14 +30,14 @@
  */
 #define uuid_hash bsd_uuid_hash
 
-#ifdef HAVE_UUID_H
+#if defined(HAVE_UUID_H)
 #include <uuid.h>
-#endif
-#ifdef HAVE_OSSP_UUID_H
+#elif defined(HAVE_OSSP_UUID_H)
 #include <ossp/uuid.h>
-#endif
-#ifdef HAVE_UUID_UUID_H
+#elif defined(HAVE_UUID_UUID_H)
 #include <uuid/uuid.h>
+#else
+#error "please use configure's --with-uuid switch to select a UUID library"
 #endif
 
 #undef uuid_hash
