configure: Check if the compiler supports ISO C89 or C99 and which parameters are...

This first checks what is required for ISO C99 support and sets the relevant
compiler parameters and if no C99 compiler is found, it checks for a
C89 compiler. This enables us to check for and use C89/C99 functions
that gcc hides from us without the correct compiler parameters.

diff --git a/configure.ac b/configure.ac
index f85d350..c4a8a85 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -218,6 +218,7 @@ dnl *** checks for programs ***
 
 dnl find a compiler
 AC_PROG_CC
+AC_PROG_CC_STDC
 
 dnl check if the compiler supports '-c' and '-o' options
 AM_PROG_CC_C_O