Added checks for compiler options.

Signed-off-by: Slava Zanko <slavazanko@gmail.com>

acinclude.m4

@@ -1,6 +1,7 @@
 m4_include([m4.include/ac_onceonly.m4])
 m4_include([m4.include/ax_path_lib_pcre.m4])
 m4_include([m4.include/dx_doxygen.m4])
+m4_include([m4.include/mc-cflags.m4])
 m4_include([m4.include/mc-check-search-type.m4])
 m4_include([m4.include/mc-mcserver.m4])
 m4_include([m4.include/ac-get-fs-info.m4])

configure.ac

@@ -515,19 +515,18 @@ if test "$GLIBC21" != yes; then
     AC_DEFINE(USE_INCLUDED_REGEX, 1, [Use the regex included here])
 fi
 
-dnl If default CFLAGS is used with gcc, add -Wall
+MC_CHECK_CFLAGS
-if test -z "$ac_env_CFLAGS_set"; then
+
-    if test -n "$GCC"; then
+CFLAGS_OPTS=" -O2 "
-	CFLAGS="$CFLAGS -Wall"
+CFLAGS_EXTRA=""
-    fi
-fi
 
 if test x$USE_MAINTAINER_MODE = xyes; then
-    CFLAGS_WARNINGS="-Wall -Werror -Wwrite-strings -Wnested-externs -Wsign-compare -Wuninitialized"
+    CFLAGS_EXTRA="-Werror"
-    CFLAGS_DEBUG="-g3 -O -ggdb"
+    CFLAGS_OPTS="-g3 -O -ggdb"
-    CFLAGS="$CFLAGS $CFLAGS_WARNINGS $CFLAGS_DEBUG"
 fi
 
+CFLAGS="$CFLAGS $mc_configured_cflags $CFLAGS_OPTS $CFLAGS_EXTRA"
+
 AC_SUBST(CFLAGS)
 AC_SUBST(CPPFLAGS)
 AC_SUBST(LDFLAGS)

m4.include/mc-cflags.m4

@@ -0,0 +1,70 @@
+dnl @synopsis MC_CHECK_CFLAGS
+dnl
+dnl Check flags supported by compilator
+dnl
+dnl @author Slava Zanko <slavazanko@gmail.com>
+dnl @version 2009-10-29
+dnl @license GPL
+dnl @copyright Free Software Foundation, Inc.
+
+AC_DEFUN([MC_CHECK_ONE_CFLAG],[
+
+    AC_MSG_CHECKING([if gcc accepts $1])
+
+  safe_CFLAGS=$CFLAGS
+  CFLAGS="$1"
+
+  AC_TRY_COMPILE(, [
+  return 0;
+  ],
+  [
+    mc_check_one_cflag=yes
+  ],
+  [
+    mc_check_one_cflag=no
+  ])
+
+  CFLAGS=$safe_CFLAGS
+  AC_MSG_RESULT([$mc_check_one_cflag])
+
+  if test x$mc_check_one_cflag = xyes; then
+    mc_configured_cflags="$mc_configured_cflags $1"
+  fi
+
+])
+
+AC_DEFUN([MC_CHECK_CFLAGS],[
+    mc_configured_cflags=""
+
+    MC_CHECK_ONE_CFLAG([-Wunused-result])
+    MC_CHECK_ONE_CFLAG([-Wimplicit-int])
+    MC_CHECK_ONE_CFLAG([-Wimplicit-function-declaration])
+    MC_CHECK_ONE_CFLAG([-Wmissing-braces])
+    MC_CHECK_ONE_CFLAG([-Wparentheses])
+    MC_CHECK_ONE_CFLAG([-Wreturn-type])
+    MC_CHECK_ONE_CFLAG([-Wswitch])
+    MC_CHECK_ONE_CFLAG([-Wunused-function])
+    MC_CHECK_ONE_CFLAG([-Wunused-label])
+    MC_CHECK_ONE_CFLAG([-Wunused-parameter])
+    MC_CHECK_ONE_CFLAG([-Wunused-value])
+    MC_CHECK_ONE_CFLAG([-Wunused-variable])
+    MC_CHECK_ONE_CFLAG([-Wuninitialized])
+    MC_CHECK_ONE_CFLAG([-Wdeclaration-after-statement])
+    MC_CHECK_ONE_CFLAG([-Wshadow])
+    MC_CHECK_ONE_CFLAG([-Wwrite-strings])
+    MC_CHECK_ONE_CFLAG([-Wsign-compare])
+    MC_CHECK_ONE_CFLAG([-Wmissing-parameter-type])
+    MC_CHECK_ONE_CFLAG([-Wmissing-prototypes])
+
+    MC_CHECK_ONE_CFLAG([-Wmissing-declarations])
+    MC_CHECK_ONE_CFLAG([-Wnested-externs])
+    MC_CHECK_ONE_CFLAG([-Wno-unreachable-code])
+    MC_CHECK_ONE_CFLAG([-Wno-long-long])
+    MC_CHECK_ONE_CFLAG([-Wpointer-sign])
+    MC_CHECK_ONE_CFLAG([-Wcomment])
+
+dnl    MC_CHECK_ONE_CFLAG([-fno-stack-protector])
+dnl    MC_CHECK_ONE_CFLAG([-Wsequence-point])
+dnl    MC_CHECK_ONE_CFLAG([-Wstrict-aliasing])
+dnl    MC_CHECK_ONE_CFLAG([-Wformat])
+])