Mesa (master): configure: Don' t override user -g or -O options for debug builds

[Ian Romanick]

Module: Mesa
Branch: master
Commit: 66decc7efa08ae9c94e4bd11038cfe8b3132d554
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=66decc7efa08ae9c94e4bd11038cfe8b3132d554

Author: Ian Romanick <ian.d.romanick at intel.com>
Date:   Mon Jul 14 11:22:20 2014 -0700

configure: Don't override user -g or -O options for debug builds

Principle of least surprise: --enable-debug should enable debugging.
Ages ago, Mesa's build system only added -g in dri-debug builds (yay for
the static Makefiles).  If you forgot to change it (or wrap the build
with custom scripts), you would often be disappointed when trying to gdb
Mesa bugs.  New developers, that may not yet have custom scripts, will
have this same issue.

I think we should enable experienced developers to do what they want,
and make things easier for new developers.  I already pass '-ggdb3 -O1'
or '-ggdb3 -Og' for CFLAGS, and I don't want configure to change them
for me.

Signed-off-by: Ian Romanick <ian.d.romanick at intel.com>
Reviewed-by: Kenneth Graunke <kenneth at whitecape.org>
Reviewed-by: Matt Turner <mattst88 at gmail.com>

---

 configure.ac |   14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/configure.ac b/configure.ac
index 3a6fde2..6b0d43f 100644
--- a/configure.ac
+++ b/configure.ac
@@ -301,10 +301,20 @@ AC_ARG_ENABLE([debug],
 if test "x$enable_debug" = xyes; then
     DEFINES="$DEFINES -DDEBUG"
     if test "x$GCC" = xyes; then
-        CFLAGS="$CFLAGS -g -O0"
+        if ! echo "$CFLAGS" | grep -q -e '-g'; then
+            CFLAGS="$CFLAGS -g"
+        fi
+        if ! echo "$CFLAGS" | grep -q -e '-O'; then
+            CFLAGS="$CFLAGS -O0"
+        fi
     fi
     if test "x$GXX" = xyes; then
-        CXXFLAGS="$CXXFLAGS -g -O0"
+        if ! echo "$CXXFLAGS" | grep -q -e '-g'; then
+            CXXFLAGS="$CXXFLAGS -g"
+        fi
+        if ! echo "$CXXFLAGS" | grep -q -e '-O'; then
+            CXXFLAGS="$CXXFLAGS -O0"
+        fi
     fi
 fi