[PATCH] drm/panfrost: Give name to anonymous coredump object union

[Steven Price]

On 12/09/2022 17:44, Adrián Larumbe wrote:
> Building Mesa's Perfetto requires including the panfrost drm uAPI header in
> C++ code, but the C++ compiler requires anonymous unions to have only
> public non-static data members.
> 
> Commit 730c2bf4ad39 ("drm/panfrost: Add support for devcoredump")
> introduces one such union, breaking the Mesa build.
> 
> Give it a name, and also rename pan_reg_hdr structure because it will
> always be prefixed by the union name.
> 
> Bug: https://gitlab.freedesktop.org/mesa/mesa/-/issues/7195
> 
> Signed-off-by: Adrián Larumbe <adrian.larumbe at collabora.com>

Ouch! It's frustrating how C++ isn't quite a superset of C. However I
think we can solve this with a simpler patch, I'd appreciate testing
that this does indeed fix the build issues with Mesa with all supported
compilers (I'm not so familiar with C++):

----8<----
>From 492714a7dff0710ac5b8b457bcfe9ae52b458565 Mon Sep 17 00:00:00 2001
From: Steven Price <steven.price at arm.com>
Date: Tue, 13 Sep 2022 09:37:55 +0100
Subject: [PATCH] drm/panfrost: Remove type name from internal structs

The two structs internal to struct panfrost_dump_object_header were
named, but sadly that is incompatible with C++, causing an error: "an
anonymous union may only have public non-static data members".

However nothing refers to struct pan_reg_hdr and struct pan_bomap_hdr
and there's no need to export these definitions, so lets drop them. This
fixes the C++ build error with the minimum change in userspace API.

Bug: https://gitlab.freedesktop.org/mesa/mesa/-/issues/7195
Fixes: 730c2bf4ad39 ("drm/panfrost: Add support for devcoredump")
Signed-off-by: Steven Price <steven.price at arm.com>
---
 include/uapi/drm/panfrost_drm.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/include/uapi/drm/panfrost_drm.h
b/include/uapi/drm/panfrost_drm.h
index eac87310b348..bd77254be121 100644
--- a/include/uapi/drm/panfrost_drm.h
+++ b/include/uapi/drm/panfrost_drm.h
@@ -242,7 +242,7 @@ struct panfrost_dump_object_header {
 	__le32 file_offset;

 	union {
-		struct pan_reg_hdr {
+		struct {
 			__le64 jc;
 			__le32 gpu_id;
 			__le32 major;
@@ -250,7 +250,7 @@ struct panfrost_dump_object_header {
 			__le64 nbos;
 		} reghdr;

-		struct pan_bomap_hdr {
+		struct {
 			__le32 valid;
 			__le64 iova;
 			__le32 data[2];
-- 
2.34.1