From 1b5531461507e887d12d6378f1535daccc8bad7b Mon Sep 17 00:00:00 2001
From: Antonio Ospite <antonio.ospite@collabora.com>
Date: Thu, 24 Jul 2025 13:47:10 +0200
Subject: [PATCH] broadcom/compiler: prevent FALLTHROUGH error with C23
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When building for the C23 standard, the compiler gives the following
error:

-----------------------------------------------------------------------
../src/broadcom/compiler/vir_register_allocate.c
../src/broadcom/compiler/vir_register_allocate.c: In function ‘update_graph_and_reg_classes_for_inst’:
../src/broadcom/compiler/vir_register_allocate.c:1225:44: error: expected statement before ‘;’ token
 1225 |                                 FALLTHROUGH;
      |                                            ^
../src/broadcom/compiler/vir_register_allocate.c:1225:44: warning: ‘fallthrough’ attribute ignored [-Wattributes]
../src/broadcom/compiler/vir_register_allocate.c:1225:44: error: suggest braces around empty body in an ‘else’ statement [-Werror=empty-body]
../src/broadcom/compiler/vir_register_allocate.c:1222:28: warning: this statement may fall through [-Wimplicit-fallthrough=]
 1222 |                         if (c->devinfo->ver >= 71)
      |                            ^
../src/broadcom/compiler/vir_register_allocate.c:1226:17: note: here
 1226 |                 case 1:
      |                 ^~~~
-----------------------------------------------------------------------

Fix that by doing what the compiler suggests, i.e. by using braces
around empty body in the ‘else’ statement.

Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/36323>
---
 src/broadcom/compiler/vir_register_allocate.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/src/broadcom/compiler/vir_register_allocate.c b/src/broadcom/compiler/vir_register_allocate.c
index dfb5b9a989a..cf2ca4e89d2 100644
--- a/src/broadcom/compiler/vir_register_allocate.c
+++ b/src/broadcom/compiler/vir_register_allocate.c
@@ -1219,10 +1219,11 @@ update_graph_and_reg_classes_for_inst(struct v3d_compile *c,
                 switch (inst->src[0].index) {
                 case 0:
                         /* V3D 7.x doesn't use rf0 for thread payload */
-                        if (c->devinfo->ver >= 71)
+                        if (c->devinfo->ver >= 71) {
                                 break;
-                        else
+                        } else {
                                 FALLTHROUGH;
+                        }
                 case 1:
                 case 2:
                 case 3: {