[llvm-branch-commits] [compiler-rt] [NFC][sanitizer] Add Debug utility to print thread history (PR #111948)

[Vitaly Buka via llvm-branch-commits]

https://github.com/vitalybuka updated https://github.com/llvm/llvm-project/pull/111948

>From 12f4a2f8ad0583d7494b21a460b131f53541022a Mon Sep 17 00:00:00 2001
From: Vitaly Buka <vitalybuka at google.com>
Date: Fri, 11 Oct 2024 11:47:10 -0700
Subject: [PATCH] prev is context

Created using spr 1.3.4
---
 .../sanitizer_common/sanitizer_thread_history.cpp    | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/compiler-rt/lib/sanitizer_common/sanitizer_thread_history.cpp b/compiler-rt/lib/sanitizer_common/sanitizer_thread_history.cpp
index 8d1b9ea3030eac..6a4d9bf231811f 100644
--- a/compiler-rt/lib/sanitizer_common/sanitizer_thread_history.cpp
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_thread_history.cpp
@@ -54,11 +54,11 @@ void PrintThreadHistory(ThreadRegistry &registry, InternalScopedString &out) {
     return parent;
   };
 
-  u32 stack_id = 0;
+  const ThreadContextBase *prev = nullptr;
   for (const ThreadContextBase *context : stacks) {
-    if (stack_id != context->stack_id) {
-      StackDepotGet(stack_id).PrintTo(&out);
-      stack_id = context->stack_id;
+    if (prev->stack_id != context->stack_id) {
+      StackDepotGet(prev->stack_id).PrintTo(&out);
+      prev = context;
     }
     out.Append("Thread ");
     describe_thread(context);
@@ -66,8 +66,8 @@ void PrintThreadHistory(ThreadRegistry &registry, InternalScopedString &out) {
     describe_thread(get_parent(context));
     out.Append("\n");
   }
-  if (!stacks.empty())
-    StackDepotGet(stack_id).PrintTo(&out);
+  if (prev)
+    StackDepotGet(prev->stack_id).PrintTo(&out);
 }
 
 }  // namespace __sanitizer