[compiler-rt] 548aa90 - [NFC][sanitizer] Lazy init in StackDepotReverseMap

[Vitaly Buka via llvm-commits]

Author: Vitaly Buka
Date: 2021-09-30T19:26:34-07:00
New Revision: 548aa9022ee79a95a07b99a88df28cee6cb0e16d

URL: https://github.com/llvm/llvm-project/commit/548aa9022ee79a95a07b99a88df28cee6cb0e16d
DIFF: https://github.com/llvm/llvm-project/commit/548aa9022ee79a95a07b99a88df28cee6cb0e16d.diff

LOG: [NFC][sanitizer] Lazy init in StackDepotReverseMap

Added: 
    

Modified: 
    compiler-rt/lib/sanitizer_common/sanitizer_stackdepot.cpp
    compiler-rt/lib/sanitizer_common/sanitizer_stackdepot.h

Removed: 
    


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diff  --git a/compiler-rt/lib/sanitizer_common/sanitizer_stackdepot.cpp b/compiler-rt/lib/sanitizer_common/sanitizer_stackdepot.cpp
index 9215867edd65c..c71b0a17496a2 100644
--- a/compiler-rt/lib/sanitizer_common/sanitizer_stackdepot.cpp
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_stackdepot.cpp
@@ -125,7 +125,9 @@ bool StackDepotReverseMap::IdDescPair::IdComparator(
   return a.id < b.id;
 }
 
-StackDepotReverseMap::StackDepotReverseMap() {
+void StackDepotReverseMap::Init() const {
+  if (LIKELY(map_.capacity()))
+    return;
   map_.reserve(StackDepotGetStats().n_uniq_ids + 100);
   for (int idx = 0; idx < StackDepot::kTabSize; idx++) {
     atomic_uintptr_t *p = &theDepot.tab[idx];
@@ -140,6 +142,7 @@ StackDepotReverseMap::StackDepotReverseMap() {
 }
 
 StackTrace StackDepotReverseMap::Get(u32 id) const {
+  Init();
   if (!map_.size())
     return StackTrace();
   IdDescPair pair = {id, nullptr};

diff  --git a/compiler-rt/lib/sanitizer_common/sanitizer_stackdepot.h b/compiler-rt/lib/sanitizer_common/sanitizer_stackdepot.h
index d4c2ee3583511..6f79fffeea8a4 100644
--- a/compiler-rt/lib/sanitizer_common/sanitizer_stackdepot.h
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_stackdepot.h
@@ -49,7 +49,7 @@ void StackDepotPrintAll();
 // which were stored before it was instantiated.
 class StackDepotReverseMap {
  public:
-  StackDepotReverseMap();
+  StackDepotReverseMap() = default;
   StackTrace Get(u32 id) const;
 
  private:
@@ -60,7 +60,9 @@ class StackDepotReverseMap {
     static bool IdComparator(const IdDescPair &a, const IdDescPair &b);
   };
 
-  InternalMmapVector<IdDescPair> map_;
+  void Init() const;
+
+  mutable InternalMmapVector<IdDescPair> map_;
 
   // Disallow evil constructors.
   StackDepotReverseMap(const StackDepotReverseMap&);