| From f107467179428a0e3ea9e4aa9738ac12ff02822d Mon Sep 17 00:00:00 2001 |
| From: Colin Watson <cjwatson@debian.org> |
| Date: Thu, 24 Feb 2022 16:04:18 +0000 |
| Subject: [PATCH] Improve detection of -fzero-call-used-regs=all support |
| |
| GCC doesn't tell us whether this option is supported unless it runs into |
| the situation where it would need to emit corresponding code. |
| |
| Upstream-Status: Backport |
| Signed-off-by: Alexander Kanavin <alex@linutronix.de> |
| --- |
| m4/openssh.m4 | 3 +++ |
| 1 file changed, 3 insertions(+) |
| |
| diff --git a/m4/openssh.m4 b/m4/openssh.m4 |
| index 4f9c3792dc1..8c33c701b8b 100644 |
| --- a/m4/openssh.m4 |
| +++ b/m4/openssh.m4 |
| @@ -14,6 +14,8 @@ AC_DEFUN([OSSH_CHECK_CFLAG_COMPILE], [{ |
| AC_COMPILE_IFELSE([AC_LANG_SOURCE([[ |
| #include <stdlib.h> |
| #include <stdio.h> |
| +/* Trivial function to help test for -fzero-call-used-regs */ |
| +void f(int n) {} |
| int main(int argc, char **argv) { |
| (void)argv; |
| /* Some math to catch -ftrapv problems in the toolchain */ |
| @@ -21,6 +23,7 @@ int main(int argc, char **argv) { |
| float l = i * 2.1; |
| double m = l / 0.5; |
| long long int n = argc * 12345LL, o = 12345LL * (long long int)argc; |
| + f(0); |
| printf("%d %d %d %f %f %lld %lld\n", i, j, k, l, m, n, o); |
| /* |
| * Test fallthrough behaviour. clang 10's -Wimplicit-fallthrough does |