From 4d5eea673230596c84e57182753f4e41ab0f6bb8 Mon Sep 17 00:00:00 2001
From: Jonathan Gray <jsg@jsg.id.au>
Date: Tue, 4 Aug 2020 18:48:34 +1000
Subject: [PATCH] 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>
(cherry picked from commit 0536b691338f2759b850f9ec94634033a5d1f9e1)
---
 .pick_status.json        |  2 +-
 src/util/u_debug_stack.c | 13 +++++--------
 2 files changed, 6 insertions(+), 9 deletions(-)

diff --git a/.pick_status.json b/.pick_status.json
index 6ab35005209..ebc7c80f6fc 100644
--- a/.pick_status.json
+++ b/.pick_status.json
@@ -1048,7 +1048,7 @@
         "description": "util: fix build with clang 10 on mips64",
         "nominated": true,
         "nomination_type": 1,
-        "resolution": 0,
+        "resolution": 1,
         "main_sha": null,
         "because_sha": "dc94a0506f1d267a761961d3ac905d77de3dae2e"
     },
diff --git a/src/util/u_debug_stack.c b/src/util/u_debug_stack.c
index 01f69e14442..86bfb2fb64b 100644
--- 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) {