cmd/dist: set -Wuninitialized only when -O is also set.

GCC on OS X 10.6 doesn't support -Wuninitialized without -O.
Fixes #7492.

LGTM=iant
R=golang-codereviews, dave, iant
CC=golang-codereviews
https://golang.org/cl/72360045

diff --git a/src/cmd/dist/build.c b/src/cmd/dist/build.c
index 6fd2f581ee6c7cab98cb5c556519ced6bb2537ee..d898a31b9ee60fafd3ccdce772204388d7c1e420 100644 (file)
--- a/src/cmd/dist/build.c
+++ b/src/cmd/dist/build.c
@@ -457,7 +457,6 @@ static char *proto_gccargs[] = {
        "-Wstrict-prototypes",
        "-Wextra",
        "-Wunused",
-       "-Wuninitialized",
        "-Wno-sign-compare",
        "-Wno-missing-braces",
        "-Wno-parentheses",
@@ -469,17 +468,19 @@ static char *proto_gccargs[] = {
        "-fno-common",
        "-ggdb",
        "-pipe",
-#if defined(__NetBSD__) && defined(__arm__)
-       // GCC 4.5.4 (NetBSD nb1 20120916) on ARM is known to mis-optimize gc/mparith3.c
-       // Fix available at http://patchwork.ozlabs.org/patch/64562/.
-       "-O1",
-#endif
 };
 
 // gccargs2 is the second part of gccargs.
 // it is used if the environment isn't defining CFLAGS.
 static char *proto_gccargs2[] = {
+       // on older versions of GCC, -Wuninitialized is not supported
+       // without -O, so put it here together with -O settings in case
+       // the user's $CFLAGS doesn't include -O.
+       "-Wuninitialized",
 #if defined(__NetBSD__) && defined(__arm__)
+       // GCC 4.5.4 (NetBSD nb1 20120916) on ARM is known to mis-optimize gc/mparith3.c
+       // Fix available at http://patchwork.ozlabs.org/patch/64562/.
+       "-O1",
 #else
        "-O2",
 #endif