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authorRich Felker <>2020-06-01 20:53:42 -0400
committerRich Felker <>2020-06-01 20:59:53 -0400
commitc40157d87ef0b585a90ff5230fdf69cddc824d7f (patch)
parent8d81ba8c0bc6fe31136cb15c9c82ef4c24965040 (diff)
suppress unwanted warnings when configuring with clang
coding style warnings enabled by default in clang have long been a source of spurious questions/bug-reports. since clang provides a -w that behaves differently from gcc's, and that lets us enable any warnings we may actually want after turning them all off to start with a clean slate, use it at configure time if clang is detected.
1 files changed, 7 insertions, 0 deletions
diff --git a/configure b/configure
index a2728969..43598825 100755
--- a/configure
+++ b/configure
@@ -495,6 +495,13 @@ fnmatch '-mtune=*|*\ -mtune=*' "$CC $CFLAGS" || tryldflag CFLAGS_AUTO -mtune=gen
+# GCC defines -w as overriding any -W options, regardless of order, but
+# clang has a bunch of annoying warnings enabled by default and needs -w
+# to start from a clean slate. So use -w if building with clang.
+test "$cc_family" = clang && tryflag CFLAGS_AUTO -w
# Even with -std=c99, gcc accepts some constructs which are constraint
# violations. We want to treat these as errors regardless of whether
# other purely stylistic warnings are enabled -- especially implicit