Provide a symbol that can always be used to signal an error,
regardless of optimization.  Usage of this should be protected
by e.g. __builtin_constant_p, which guards for optimization.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 include/qemu/compiler.h | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/include/qemu/compiler.h b/include/qemu/compiler.h
index d620a841e4..cf28bb2bcd 100644
--- a/include/qemu/compiler.h
+++ b/include/qemu/compiler.h
@@ -215,9 +215,10 @@
  * supports QEMU_ERROR, this will be reported at compile time; otherwise
  * this will be reported at link time due to the missing symbol.
  */
-#if defined(__OPTIMIZE__) && !defined(__NO_INLINE__)
 extern void QEMU_NORETURN QEMU_ERROR("code path is reachable")
-    qemu_build_not_reached(void);
+    qemu_build_not_reached_always(void);
+#if defined(__OPTIMIZE__) && !defined(__NO_INLINE__)
+#define qemu_build_not_reached()  qemu_build_not_reached_always()
 #else
 #define qemu_build_not_reached()  g_assert_not_reached()
 #endif
-- 
2.25.1

On 1/19/21 7:55 PM, Richard Henderson wrote:
> Provide a symbol that can always be used to signal an error,
> regardless of optimization.  Usage of this should be protected
> by e.g. __builtin_constant_p, which guards for optimization.
> 
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
> ---
>  include/qemu/compiler.h | 5 +++--
>  1 file changed, 3 insertions(+), 2 deletions(-)

Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>