_ISOC99_SOURCE -> _GNU_SOURCE

[exim.git] / src / src / exim.h

diff --git a/src/src/exim.h b/src/src/exim.h
index 987aebf838d354da59a6753468f13dbea9361e80..c18c9aef3f906d2e9b59133093ce7068d71a2786 100644 (file)
--- a/src/src/exim.h
+++ b/src/src/exim.h
@@ -21,9 +21,11 @@ This call dates back at least as far as SUSv2. */
 #define HAVE_SRANDOM
 
 /* This is primarily for the Gnu C library; we define it before os.h so that
-os.h has a chance to hurriedly undef it, Just In Case. */
+os.h has a chance to hurriedly undef it, Just In Case.  We need C99 for some
+64-bit math support, and defining _ISOC99_SOURCE breaks <resolv.h> and friends.
+*/
 
-#define _ISOC99_SOURCE 1
+#define _GNU_SOURCE 1
 
 /* First of all include the os-specific header, which might set things that
 are needed by any of the other headers, including system headers. */