From a04b5ebd3c9292df4e87c1146447f49718bbd29c Mon Sep 17 00:00:00 2001
From: Konstantin Seurer <konstantin.seurer@gmail.com>
Date: Mon, 24 Feb 2025 19:50:13 +0100
Subject: [PATCH] nir/sweep: Fix handling instructions with debug info

When debug information is present, the nir_instr pointer is not the
start of the allocation.

Reviewed-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/28613>
---
 src/compiler/nir/nir.c       | 9 ---------
 src/compiler/nir/nir.h       | 9 +++++++++
 src/compiler/nir/nir_sweep.c | 8 +++++++-
 3 files changed, 16 insertions(+), 10 deletions(-)

diff --git a/src/compiler/nir/nir.c b/src/compiler/nir/nir.c
index c2f816c7bb6..eb05cea70bc 100644
--- a/src/compiler/nir/nir.c
+++ b/src/compiler/nir/nir.c
@@ -817,15 +817,6 @@ nir_tex_instr_create(nir_shader *shader, unsigned num_srcs)
    return instr;
 }
 
-static void *
-nir_instr_get_gc_pointer(nir_instr *instr)
-{
-   if (unlikely(instr->has_debug_info))
-      return nir_instr_get_debug_info(instr);
-
-   return instr;
-}
-
 static gc_ctx *
 nir_instr_get_gc_context(nir_instr *instr)
 {
diff --git a/src/compiler/nir/nir.h b/src/compiler/nir/nir.h
index 31a658c6e50..a41e9e36739 100644
--- a/src/compiler/nir/nir.h
+++ b/src/compiler/nir/nir.h
@@ -4241,6 +4241,15 @@ nir_instr_get_debug_info(nir_instr *instr)
    return container_of(instr, nir_instr_debug_info, instr);
 }
 
+static inline void *
+nir_instr_get_gc_pointer(nir_instr *instr)
+{
+   if (unlikely(instr->has_debug_info))
+      return nir_instr_get_debug_info(instr);
+
+   return instr;
+}
+
 typedef bool (*nir_foreach_def_cb)(nir_def *def, void *state);
 typedef bool (*nir_foreach_src_cb)(nir_src *src, void *state);
 static inline bool nir_foreach_src(nir_instr *instr, nir_foreach_src_cb cb, void *state);
diff --git a/src/compiler/nir/nir_sweep.c b/src/compiler/nir/nir_sweep.c
index bf6278af38a..29caf897193 100644
--- a/src/compiler/nir/nir_sweep.c
+++ b/src/compiler/nir/nir_sweep.c
@@ -49,7 +49,13 @@ sweep_block(nir_shader *nir, nir_block *block)
    ralloc_steal(nir, block);
 
    nir_foreach_instr(instr, block) {
-      gc_mark_live(nir->gctx, instr);
+      gc_mark_live(nir->gctx, nir_instr_get_gc_pointer(instr));
+
+      if (instr->has_debug_info) {
+         nir_instr_debug_info *debug_info = nir_instr_get_debug_info(instr);
+         ralloc_steal(nir, debug_info->filename);
+         ralloc_steal(nir, debug_info->variable_name);
+      }
 
       switch (instr->type) {
       case nir_instr_type_tex: