From c9b5e685aed2bf2bd2faa0566b90196f6e9eb7ba Mon Sep 17 00:00:00 2001
From: Francis Ricci <francisjricci@gmail.com>
Date: Fri, 29 Sep 2017 20:55:06 +0000
Subject: Move LoadedModule list to a NoCtor vector and initialize on demand.

Unreverting this patch because llvm-clang-lld-x86_64-debian-fast started
passing again before the revert hit. Must've been just a flake.

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@314556 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/sanitizer_common/sanitizer_common.h           | 9 +++++++--
 lib/sanitizer_common/sanitizer_linux_libcdep.cc   | 6 +++---
 lib/sanitizer_common/sanitizer_mac.cc             | 2 +-
 lib/sanitizer_common/sanitizer_procmaps.h         | 2 +-
 lib/sanitizer_common/sanitizer_procmaps_common.cc | 2 +-
 lib/sanitizer_common/sanitizer_procmaps_mac.cc    | 2 +-
 lib/sanitizer_common/sanitizer_win.cc             | 2 +-
 7 files changed, 15 insertions(+), 10 deletions(-)

diff --git a/lib/sanitizer_common/sanitizer_common.h b/lib/sanitizer_common/sanitizer_common.h
index 47b02b149..11ee59024 100644
--- a/lib/sanitizer_common/sanitizer_common.h
+++ b/lib/sanitizer_common/sanitizer_common.h
@@ -727,7 +727,7 @@ class LoadedModule {
 // filling this information.
 class ListOfModules {
  public:
-  ListOfModules() : modules_(kInitialCapacity) {}
+  ListOfModules() : initialized(false) {}
   ~ListOfModules() { clear(); }
   void init();
   const LoadedModule *begin() const { return modules_.begin(); }
@@ -745,10 +745,15 @@ class ListOfModules {
     for (auto &module : modules_) module.clear();
     modules_.clear();
   }
+  void clearOrInit() {
+    initialized ? clear() : modules_.Initialize(kInitialCapacity);
+    initialized = true;
+  }
 
-  InternalMmapVector<LoadedModule> modules_;
+  InternalMmapVectorNoCtor<LoadedModule> modules_;
   // We rarely have more than 16K loaded modules.
   static const uptr kInitialCapacity = 1 << 14;
+  bool initialized;
 };
 
 // Callback type for iterating over a set of memory ranges.
diff --git a/lib/sanitizer_common/sanitizer_linux_libcdep.cc b/lib/sanitizer_common/sanitizer_linux_libcdep.cc
index da715dc6c..0f420875d 100644
--- a/lib/sanitizer_common/sanitizer_linux_libcdep.cc
+++ b/lib/sanitizer_common/sanitizer_linux_libcdep.cc
@@ -424,7 +424,7 @@ typedef ElfW(Phdr) Elf_Phdr;
 # endif
 
 struct DlIteratePhdrData {
-  InternalMmapVector<LoadedModule> *modules;
+  InternalMmapVectorNoCtor<LoadedModule> *modules;
   bool first;
 };
 
@@ -473,13 +473,13 @@ static bool requiresProcmaps() {
 #endif
 }
 
-static void procmapsInit(InternalMmapVector<LoadedModule> *modules) {
+static void procmapsInit(InternalMmapVectorNoCtor<LoadedModule> *modules) {
   MemoryMappingLayout memory_mapping(false);
   memory_mapping.DumpListOfModules(modules);
 }
 
 void ListOfModules::init() {
-  clear();
+  clearOrInit();
   if (requiresProcmaps()) {
     procmapsInit(&modules_);
   } else {
diff --git a/lib/sanitizer_common/sanitizer_mac.cc b/lib/sanitizer_common/sanitizer_mac.cc
index 1570ae277..cd63cb42f 100644
--- a/lib/sanitizer_common/sanitizer_mac.cc
+++ b/lib/sanitizer_common/sanitizer_mac.cc
@@ -411,7 +411,7 @@ void GetThreadStackAndTls(bool main, uptr *stk_addr, uptr *stk_size,
 }
 
 void ListOfModules::init() {
-  clear();
+  clearOrInit();
   MemoryMappingLayout memory_mapping(false);
   memory_mapping.DumpListOfModules(&modules_);
 }
diff --git a/lib/sanitizer_common/sanitizer_procmaps.h b/lib/sanitizer_common/sanitizer_procmaps.h
index 96d0b2f9d..d462ad841 100644
--- a/lib/sanitizer_common/sanitizer_procmaps.h
+++ b/lib/sanitizer_common/sanitizer_procmaps.h
@@ -76,7 +76,7 @@ class MemoryMappingLayout {
   static void CacheMemoryMappings();
 
   // Adds all mapped objects into a vector.
-  void DumpListOfModules(InternalMmapVector<LoadedModule> *modules);
+  void DumpListOfModules(InternalMmapVectorNoCtor<LoadedModule> *modules);
 
  private:
   void LoadFromCache();
diff --git a/lib/sanitizer_common/sanitizer_procmaps_common.cc b/lib/sanitizer_common/sanitizer_procmaps_common.cc
index 30663e8c6..b9298d4cc 100644
--- a/lib/sanitizer_common/sanitizer_procmaps_common.cc
+++ b/lib/sanitizer_common/sanitizer_procmaps_common.cc
@@ -120,7 +120,7 @@ void MemoryMappingLayout::LoadFromCache() {
 }
 
 void MemoryMappingLayout::DumpListOfModules(
-    InternalMmapVector<LoadedModule> *modules) {
+    InternalMmapVectorNoCtor<LoadedModule> *modules) {
   Reset();
   InternalScopedString module_name(kMaxPathLength);
   MemoryMappedSegment segment(module_name.data(), module_name.size());
diff --git a/lib/sanitizer_common/sanitizer_procmaps_mac.cc b/lib/sanitizer_common/sanitizer_procmaps_mac.cc
index 786876f04..3b98ff095 100644
--- a/lib/sanitizer_common/sanitizer_procmaps_mac.cc
+++ b/lib/sanitizer_common/sanitizer_procmaps_mac.cc
@@ -353,7 +353,7 @@ bool MemoryMappingLayout::Next(MemoryMappedSegment *segment) {
 }
 
 void MemoryMappingLayout::DumpListOfModules(
-    InternalMmapVector<LoadedModule> *modules) {
+    InternalMmapVectorNoCtor<LoadedModule> *modules) {
   Reset();
   InternalScopedString module_name(kMaxPathLength);
   MemoryMappedSegment segment(module_name.data(), kMaxPathLength);
diff --git a/lib/sanitizer_common/sanitizer_win.cc b/lib/sanitizer_common/sanitizer_win.cc
index a144db28c..84065aa0e 100644
--- a/lib/sanitizer_common/sanitizer_win.cc
+++ b/lib/sanitizer_common/sanitizer_win.cc
@@ -524,7 +524,7 @@ static uptr GetPreferredBase(const char *modname) {
 }
 
 void ListOfModules::init() {
-  clear();
+  clearOrInit();
   HANDLE cur_process = GetCurrentProcess();
 
   // Query the list of modules.  Start by assuming there are no more than 256
-- 
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