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

[Adrián Larumbe]

Hi Steven,

On 13.09.2022 09:45, Steven Price wrote:
>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++):

I just tested your changes on Mesa and they do fix the build.

>----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