+
+warn=''
+
+# Add -Wall for the core modules iff gcc and not already -Wall
+case "$gccversion" in
+'') ;;
+Intel*) ;; # The Intel C++ plays gcc on TV but is not really it.
+*) case "$ccflags" in
+ *-Wall*) ;;
+ *) warn="$warn -Wall" ;;
+ esac
+ ;;
+esac
+
+# Create a test source file for testing what options can be fed to
+# gcc in this system; include a selection of most common and commonly
+# hairy include files.
+
+cat >_cflags.c <<__EOT__
+#include "EXTERN.h"
+#include "perl.h"
+/* The stdio.h, errno.h, and setjmp.h should be there in any ANSI C89. */
+#include <stdio.h>
+#include <errno.h>
+#include <setjmp.h>
+/* Just in case the inclusion of perl.h did not
+ * pull in enough system headers, let's try again. */
+#ifdef I_STDLIB
+#include <stdlib.h>
+#endif
+#ifdef I_STDDEF
+#include <stddef.h>
+#endif
+#ifdef I_STDARG
+#include <stdarg.h>
+#endif
+#ifdef I_LIMITS
+#include <limits.h>
+#endif
+#ifdef I_DIRENT
+#include <dirent.h>
+#endif
+#ifdef I_UNISTD
+#include <unistd.h>
+#endif
+#ifdef I_SYSTYPES
+#include <sys/types.h>
+#endif
+#ifdef I_SYSPARAM
+#include <sys/param.h>
+#endif
+#ifdef I_SYSRESOURCE
+#include <sys/resource.h>
+#endif
+#ifdef I_SYSSELECT
+#include <sys/select.h>
+#endif
+#if defined(HAS_SOCKET) && !defined(VMS) && !defined(WIN32) /* See perl.h. */
+#include <sys/socket.h>
+#endif
+#ifdef I_SYSSTAT
+#include <sys/stat.h>
+#endif
+#ifdef I_SYSTIME
+#include <sys/time.h>
+#endif
+#ifdef I_SYSTIMES
+#include <sys/times.h>
+#endif
+#ifdef I_SYSWAIT
+#include <sys/wait.h>
+#endif
+/* The gcc -ansi can cause a lot of noise in Solaris because of:
+ /usr/include/sys/resource.h:148: warning: 'struct rlimit64' declared inside parameter list
+ */
+int main(int argc, char *argv[]) {
+
+/* Add here test code found to be problematic in some gcc platform. */
+
+/* Off_t/off_t is a struct in Solaris with largefiles, and with gcc -ansi
+ * that struct cannot be compared in some gcc releases with a flat
+ * integer, such as a STRLEN. */
+
+ Off_t t0a = 2;
+ STRLEN t0b = 3;
+ int t0c = t0a == t0b;
+
+ return 0;
+}
+__EOT__
+
+stdflags=''
+
+# Further gcc warning options.
+case "$gccversion" in
+'') ;;
+[12]*) ;; # gcc versions 1 (gasp!) and 2 are not good for this.
+Intel*) ;; # # Is that you, Intel C++?
+*) for opt in -ansi -pedantic -std=c89 -W -Wextra -Wdeclaration-after-statement -Wendif-labels
+ do
+ case " $ccflags " in
+ *" $opt "*) ;; # Skip if already there.
+ *) rm -f _cflags$_exe
+ case "`$cc $cflags $opt _cflags.c -o _cflags$_exe 2>&1`" in
+ *"unrecognized"*) ;;
+ *"Invalid"*) ;;
+ *"is valid for C"*) ;;
+ *) if test -x _cflags$_exe
+ then
+ case "$opt" in
+ -std*) stdflags="$stdflags $opt" ;;
+ *) warn="$warn $opt" ;;
+ esac
+ fi
+ ;;
+ esac
+ ;;
+ esac
+ done
+ ;;
+esac
+rm -f _cflags.c _cflags$_exe
+
+case "$gccversion" in
+'') ;;
+*)
+ # If we have -Duse64bitint (or equivalent) in effect and the quadtype
+ # has become 'long long', gcc -pedantic becomes unbearable (moreso
+ # when combined with -Wall) because long long and LL and %lld|%Ld
+ # become warn-worthy. So let's drop the -pedantic in that case.
+ case "$quadtype:$sPRId64" in
+ "long long"*|*lld*|*Ld*)
+ ccflags="`echo $ccflags|sed 's/-pedantic/ /'`"
+ warn="`echo $warn|sed 's/-pedantic/ /'`"
+ ;;
+ esac
+ # Using certain features (like the gcc statement expressions)
+ # requires knowing whether -pedantic has been specified.
+ case "$warn$ccflags" in
+ *-pedantic*) warn="$warn -DPERL_GCC_PEDANTIC" ;;
+ esac
+ ;;
+esac
+
+# Code to set any extra flags here.
+extra=''
+