Move C99 compatibility to configure.ac

configure.ac

@@ -6,16 +6,11 @@ AM_INIT_AUTOMAKE([gnu -Wall -Werror])
 AC_CONFIG_SRCDIR([src/main.c])
 AC_CONFIG_HEADERS([src/config.h])
 AC_CONFIG_MACRO_DIR([m4])
+AC_USE_SYSTEM_EXTENSIONS([_GNU_SOURCE])
 
 # Enable maintainer mode by default for development
 AM_MAINTAINER_MODE([enable])
 
-# Set compiler compatibility flags
-AC_PROG_CPP_WERROR
-AC_PROG_CC_STDC
-AC_PROG_CC_C99
-AC_USE_SYSTEM_EXTENSIONS([_GNU_SOURCE])
-
 # Initialize libtool
 LT_INIT
 
@@ -25,6 +20,10 @@ AC_PROG_LEX
 AC_PROG_YACC
 AC_PROG_INSTALL
 
+# Set compiler compatibility flags
+AC_PROG_CPP_WERROR
+AC_PROG_CC_C99
+
 # Checks for libraries.
 # FIXME: Replace `main' with a function in `-lm':
 AC_CHECK_LIB([m], [pow])

src/Makefile.am

@@ -5,7 +5,6 @@ sbin_PROGRAMS = knotd
 
 # FIXME: Move header files to $(topdir)/include
 AM_CFLAGS =		\
-	-std=gnu99	\
 	-D_XOPEN_SOURCE=600 \
 	-D_GNU_SOURCE