From 0aa640a303804c49a50309ae2fd77851e2030fb1 Mon Sep 17 00:00:00 2001
From: John Snow <jsnow@redhat.com>
Date: Fri, 9 Mar 2018 11:49:31 -0500
Subject: [PATCH] configure: factor out supported flag check

Factor out the function that checks if a compiler
flag is supported or not.

Backports commit 93b25869228a3c0c632a6aa66624cc4e549ba14a from qemu
---
 qemu/configure | 27 +++++++++++++++++----------
 1 file changed, 17 insertions(+), 10 deletions(-)

diff --git a/qemu/configure b/qemu/configure
index 298480b8..b8f2537f 100755
--- a/qemu/configure
+++ b/qemu/configure
@@ -268,6 +268,12 @@ EOF
   compile_object
 }
 
+write_c_skeleton() {
+  cat > $TMPC <<EOF
+int main(void) { return 0; }
+EOF
+}
+
 if check_define __linux__ ; then
   targetos="Linux"
 elif check_define _WIN32 ; then
@@ -475,9 +481,7 @@ if test "$mingw32" = "yes" ; then
   # enable C99/POSIX format strings (needs mingw32-runtime 3.15 or later)
   QEMU_CFLAGS="-D__USE_MINGW_ANSI_STDIO=1 $QEMU_CFLAGS"
   LIBS="-lwinmm -lws2_32 -liphlpapi $LIBS"
-cat > $TMPC << EOF
-int main(void) { return 0; }
-EOF
+  write_c_skeleton;
   if compile_prog "" "-liberty" ; then
     LIBS="-liberty $LIBS"
   fi
@@ -705,16 +709,19 @@ gcc_flags="-Wno-string-plus-int $gcc_flags"
 # enable it for all configure tests. If a configure test failed due
 # to -Werror this would just silently disable some features,
 # so it's too error prone.
-cat > $TMPC << EOF
-int main(void) { return 0; }
-EOF
-for flag in $gcc_flags; do
+cc_has_warning_flag() {
+    write_c_skeleton;
+
     # Use the positive sense of the flag when testing for -Wno-wombat
     # support (gcc will happily accept the -Wno- form of unknown
     # warning options).
-    optflag="$(echo $flag | sed -e 's/^-Wno-/-W/')"
-    if compile_prog "-Werror $optflag" "" ; then
-	QEMU_CFLAGS="$QEMU_CFLAGS $flag"
+    optflag="$(echo $1 | sed -e 's/^-Wno-/-W/')"
+    compile_prog "-Werror $optflag" ""
+}
+
+for flag in $gcc_flags; do
+    if cc_has_warning_flag $flag ; then
+        QEMU_CFLAGS="$QEMU_CFLAGS $flag"
     fi
 done