Stop using -fzero-call-used-regs=all

... since it seems to be problematic with several different versions of
clang.  Only use -fzero-call-used-regs=used which is less
problematic, except with Apple's clang where we don't use it at all.
bz#3629, ok djm@

diff --git a/configure.ac b/configure.ac
index 92540d0343c68a8436cb3bb62a2a8836ae430095..36e1028e128a094de632195bb021aa60682fa8cb 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -231,9 +231,12 @@ if test "$GCC" = "yes" || test "$GCC" = "egcs"; then
        # clang 15 seems to have a bug in -fzero-call-used-regs=all.  See
        # https://bugzilla.mindrot.org/show_bug.cgi?id=3475 and
        # https://github.com/llvm/llvm-project/issues/59242
+       # clang 17 has a different bug that causes an ICE when using this
+       # flag at all (https://bugzilla.mindrot.org/show_bug.cgi?id=3629)
        case "$CLANG_VER" in
-       15.*|apple*) OSSH_CHECK_CFLAG_COMPILE([-fzero-call-used-regs=used]) ;;
-       *)    OSSH_CHECK_CFLAG_COMPILE([-fzero-call-used-regs=all]) ;;
+       apple-15*) OSSH_CHECK_CFLAG_COMPILE([-fzero-call-used-regs=used]) ;;
+       17*)    ;;
+       *)      OSSH_CHECK_CFLAG_COMPILE([-fzero-call-used-regs=used]) ;;
        esac
        OSSH_CHECK_CFLAG_COMPILE([-ftrivial-auto-var-init=zero])
     fi