util: fix build with clang 10 on mips64

On mips64, the compiler does not allow use of non-zero argument with
__builtin_frame_address(). However, the returned frame address is only
used when PIPE_ARCH_X86 is defined. The compile error can be avoided
by making #ifdef PIPE_ARCH_X86 cover the getting of frame address too.

The argument checking of __builtin_frame_address() has been present
as a debug assert in clang 8. In clang 10, there is a proper runtime
check for the argument. This is why the build has not failed before.

Fixes: dc94a0506f1 ("gallium: Do not add -Wframe-address option for gcc <= 4.4.")
from Visa Hankala

Signed-off-by: Jonathan Gray <jsg@jsg.id.au>
Reviewed-by: Ilia Mirkin <imirkin@alum.mit.edu>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/6511>

diff --git a/src/util/u_debug_stack.c b/src/util/u_debug_stack.c
index 01f69e1..86bfb2f 100644 (file)
--- a/src/util/u_debug_stack.c
+++ b/src/util/u_debug_stack.c
@@ -199,7 +199,6 @@ debug_backtrace_capture(struct debug_stack_frame *backtrace,
                         unsigned start_frame,
                         unsigned nr_frames)
 {
-   const void **frame_pointer = NULL;
    unsigned i = 0;
 
    if (!nr_frames) {
@@ -250,21 +249,21 @@ debug_backtrace_capture(struct debug_stack_frame *backtrace,
    }
 #endif
 
+#ifdef PIPE_ARCH_X86
 #if defined(PIPE_CC_GCC) && (PIPE_CC_GCC_VERSION > 404) || defined(__clang__)
 #pragma GCC diagnostic push
 #pragma GCC diagnostic ignored "-Wframe-address"
-   frame_pointer = ((const void **)__builtin_frame_address(1));
+   const void **frame_pointer = ((const void **)__builtin_frame_address(1));
 #pragma GCC diagnostic pop
-#elif defined(PIPE_CC_MSVC) && defined(PIPE_ARCH_X86)
+#elif defined(PIPE_CC_MSVC)
    __asm {
       mov frame_pointer, ebp
    }
-   frame_pointer = (const void **)frame_pointer[0];
+   const void **frame_pointer = (const void **)frame_pointer[0];
 #else
-   frame_pointer = NULL;
+   const void **frame_pointer = NULL;
 #endif
 
-#ifdef PIPE_ARCH_X86
    while (nr_frames) {
       const void **next_frame_pointer;
 
@@ -287,8 +286,6 @@ debug_backtrace_capture(struct debug_stack_frame *backtrace,
 
       frame_pointer = next_frame_pointer;
    }
-#else
-   (void) frame_pointer;
 #endif
 
    while (nr_frames) {