Build: Only use -Werror on debug builds.
What the developer wrote
Authored by Rusty Russell
Build: Only use -Werror on debug builds.
Otherwise, we can break people's builds if they upgrade compiler, for example.
Yet we still want -Werror for developers, and CI.
Changelog-Changed: Build: We no longer use `-Werror` by default, unless --enable-debugbuild is set.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
What changed, and why it matters
This commit changes the build system so that compiler warnings no longer stop the build by default. It only enforces that strict rule ('-Werror') for debug builds and for developers/CI. This is a build-configuration change, not a fix for a software vulnerability.
No security action required. Treat as a normal build-system improvement. Review downstream packaging to confirm expected compiler warning behavior for release builds.
Security signals we found
No security-relevant code change
Build-system-only modification
No memory safety, cryptographic, or protocol changes
No vulnerability fix or mitigation
Evidence from the diff
The patch removes ‘-Werror’ from BASE_WARNFLAGS and appends it only when DEBUGBUILD=1 in default_cwarnflags(). It also adds ‘-Werror’ explicitly to a linker feature-test compilation in have_function_sections() because that test intentionally wants warnings to fail. The change prevents release builds from breaking when newer compilers introduce warnings, while keeping strict warning-as-error behavior for debug/CI builds.
Changed components
configure scriptbuild flags (CWARNFLAGS / BASE_WARNFLAGS)Inspect captured patch +11 / −5
diff --git a/configure b/configure
index bee8ab19..0aa1669a 100755
--- a/configure
+++ b/configure
@@ -6,7 +6,7 @@ set -e
CONFIGURATOR=ccan/tools/configurator/configurator
CONFIG_VAR_FILE=config.vars
CONFIG_HEADER=ccan/config.h
-BASE_WARNFLAGS="-Wall -Wundef -Wmissing-prototypes -Wmissing-declarations -Wstrict-prototypes -Wold-style-definition -Werror"
+BASE_WARNFLAGS="-Wall -Wundef -Wmissing-prototypes -Wmissing-declarations -Wstrict-prototypes -Wold-style-definition"
OS=$(uname -s)
ARCH=$(uname -m)
@@ -51,7 +51,7 @@ default_coptflags()
fi
}
-# Given COPTFLAGS, HAVE_GCC and HAVE_MODERN_GCC, what CWARNFLAGS to default to?
+# Given COPTFLAGS, HAVE_GCC, HAVE_MODERN_GCC and DEBUGBUILD, what CWARNFLAGS to default to?
default_cwarnflags()
{
F=$BASE_WARNFLAGS
@@ -66,6 +66,10 @@ default_cwarnflags()
# this gcc-only.
F="$F -Wshadow=local"
fi
+ # Debug builds get -Werror (great for CI!)
+ if [ "$4" = 1 ]; then
+ F="$F -Werror"
+ fi
echo "$F"
}
@@ -220,7 +224,8 @@ have_function_sections()
TMPOBJFILE=$CONFIG_VAR_FILE.$$.o
echo "int foo(void); int foo(void) { return 0; }" > $TMPCFILE
- $1 $2 -ffunction-sections -Wl,--gc-sections -c $TMPCFILE -o $TMPOBJFILE
+ # We *want* this to fail if we get a warning, hence use -Werror.
+ $1 $2 -Werror -ffunction-sections -Wl,--gc-sections -c $TMPCFILE -o $TMPOBJFILE
}
usage()
@@ -231,7 +236,7 @@ usage()
set_defaults
DEFAULT_COPTFLAGS="$(default_coptflags $DEBUGBUILD)"
# We assume we have a modern gcc.
- DEFAULT_CWARNFLAGS="$(default_cwarnflags ""$DEFAULT_COPTFLAGS"" 1 1)"
+ DEFAULT_CWARNFLAGS="$(default_cwarnflags ""$DEFAULT_COPTFLAGS"" 1 1 ""$DEBUGBUILD"")"
usage_with_default "CC" "$CC"
usage_with_default "CWARNFLAGS" "$DEFAULT_CWARNFLAGS"
usage_with_default "COPTFLAGS" "$DEFAULT_COPTFLAGS"
@@ -601,7 +606,8 @@ fi
if [ -z ${CWARNFLAGS+x} ]; then
CWARNFLAGS=$(default_cwarnflags "$COPTFLAGS" \
$(sed -n 's/^HAVE_GCC=//p' < $CONFIG_VAR_FILE.$$) \
- $(sed -n 's/^HAVE_MODERN_GCC=//p' < $CONFIG_VAR_FILE.$$) )
+ $(sed -n 's/^HAVE_MODERN_GCC=//p' < $CONFIG_VAR_FILE.$$) \
+ "$DEBUGBUILD")
fi
add_var PREFIX "$PREFIX"
Why this scored 20/100
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