Issue #24324: Do not enable unreachable code warnings when using
gcc as the option does not work correctly in older versions of gcc
and has been silently removed as of gcc-4.5.
diff --git a/configure.ac b/configure.ac
index 94632f2..bacb7b0 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1483,14 +1483,23 @@
]))
CFLAGS="$save_CFLAGS"
CC="$ac_save_cc"
- AC_MSG_RESULT($ac_cv_enable_unreachable_code_warning)
# Don't enable unreachable code warning in debug mode, since it usually
# results in non-standard code paths.
- if test $ac_cv_enable_unreachable_code_warning = yes && test "$Py_DEBUG" != "true"
+ # Issue #24324: Unfortunately, the unreachable code warning does not work
+ # correctly on gcc and has been silently removed from the compiler.
+ # It is supported on clang but on OS X systems gcc may be an alias
+ # for clang. Try to determine if the compiler is not really gcc and,
+ # if so, only then enable the warning.
+ if test $ac_cv_enable_unreachable_code_warning = yes && \
+ test "$Py_DEBUG" != "true" && \
+ test -z "`$CC --version 2>/dev/null | grep 'Free Software Foundation'`"
then
BASECFLAGS="$BASECFLAGS -Wunreachable-code"
+ else
+ ac_cv_enable_unreachable_code_warning=no
fi
+ AC_MSG_RESULT($ac_cv_enable_unreachable_code_warning)
# if using gcc on alpha, use -mieee to get (near) full IEEE 754
# support. Without this, treatment of subnormals doesn't follow