From: Richard Smith <richard-llvm@metafoo.co.uk>
Date: Tue, 5 Sep 2017 21:46:22 +0000 (+0000)
Subject: Fix memory leak after r312467. The ModuleMap is the owner of the global module object... 
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=76d554642795496a2936ac28b1b17e4adfa923c6;p=clang

Fix memory leak after r312467. The ModuleMap is the owner of the global module object until it's reparented under a real module.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@312580 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/include/clang/Lex/ModuleMap.h b/include/clang/Lex/ModuleMap.h
index 9cca016751..4e600ce855 100644
--- a/include/clang/Lex/ModuleMap.h
+++ b/include/clang/Lex/ModuleMap.h
@@ -82,22 +82,26 @@ class ModuleMap {
   
   /// \brief The directory used for Clang-supplied, builtin include headers,
   /// such as "stdint.h".
-  const DirectoryEntry *BuiltinIncludeDir;
+  const DirectoryEntry *BuiltinIncludeDir = nullptr;
   
   /// \brief Language options used to parse the module map itself.
   ///
   /// These are always simple C language options.
   LangOptions MMapLangOpts;
 
-  // The module that the main source file is associated with (the module
-  // named LangOpts::CurrentModule, if we've loaded it).
-  Module *SourceModule;
+  /// The module that the main source file is associated with (the module
+  /// named LangOpts::CurrentModule, if we've loaded it).
+  Module *SourceModule = nullptr;
+
+  /// The global module for the current TU, if we still own it. (Ownership is
+  /// transferred if/when we create an enclosing module.
+  std::unique_ptr<Module> PendingGlobalModule;
 
   /// \brief The top-level modules that are known.
   llvm::StringMap<Module *> Modules;
 
   /// \brief The number of modules we have created in total.
-  unsigned NumCreatedModules;
+  unsigned NumCreatedModules = 0;
 
 public:
   /// \brief Flags describing the role of a module header.
diff --git a/lib/Lex/ModuleMap.cpp b/lib/Lex/ModuleMap.cpp
index db2f952e3c..b01080e55a 100644
--- a/lib/Lex/ModuleMap.cpp
+++ b/lib/Lex/ModuleMap.cpp
@@ -256,8 +256,7 @@ ModuleMap::ModuleMap(SourceManager &SourceMgr, DiagnosticsEngine &Diags,
                      const LangOptions &LangOpts, const TargetInfo *Target,
                      HeaderSearch &HeaderInfo)
     : SourceMgr(SourceMgr), Diags(Diags), LangOpts(LangOpts), Target(Target),
-      HeaderInfo(HeaderInfo), BuiltinIncludeDir(nullptr),
-      SourceModule(nullptr), NumCreatedModules(0) {
+      HeaderInfo(HeaderInfo) {
   MMapLangOpts.LineComment = true;
 }
 
@@ -747,10 +746,12 @@ std::pair<Module *, bool> ModuleMap::findOrCreateModule(StringRef Name,
 }
 
 Module *ModuleMap::createGlobalModuleForInterfaceUnit(SourceLocation Loc) {
-  auto *Result = new Module("<global>", Loc, nullptr, /*IsFramework*/ false,
-                            /*IsExplicit*/ true, NumCreatedModules++);
-  Result->Kind = Module::GlobalModuleFragment;
-  return Result;
+  assert(!PendingGlobalModule && "created multiple global modules");
+  PendingGlobalModule.reset(
+      new Module("<global>", Loc, nullptr, /*IsFramework*/ false,
+                 /*IsExplicit*/ true, NumCreatedModules++));
+  PendingGlobalModule->Kind = Module::GlobalModuleFragment;
+  return PendingGlobalModule.get();
 }
 
 Module *ModuleMap::createModuleForInterfaceUnit(SourceLocation Loc,
@@ -766,7 +767,10 @@ Module *ModuleMap::createModuleForInterfaceUnit(SourceLocation Loc,
   Modules[Name] = SourceModule = Result;
 
   // Reparent the current global module fragment as a submodule of this module.
+  assert(GlobalModule == PendingGlobalModule.get() &&
+         "unexpected global module");
   GlobalModule->setParent(Result);
+  PendingGlobalModule.release(); // now owned by parent
 
   // Mark the main source file as being within the newly-created module so that
   // declarations and macros are properly visibility-restricted to it.