Try to plug some memory leaks...

1) Sema::ParseAST now constructs a TranslationUnit object to own the top-level Decls, which releases the top-level Decls upon exiting ParseAST.

2) Bug fix: TranslationUnit::~TranslationUnit handles the case where a Decl is added more than once as a top-level Decl.

3) Decl::Destroy is now a virtual method, obviating the need for a special dispatch based on DeclKind.

3) FunctionDecl::Destroy now releases its Body using its Destroy method.

4) Added Stmt::Destroy and Stmt::DestroyChildren, which recursively delete the child ASTs of a Stmt and call their dstors.  We may need to special case dstor/Destroy methods for particular Stmt subclasses that own other dynamically allocated objects besides AST nodes.

5) REGRESSION: We temporarily are not deallocating attributes; a FIXME is provided.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@51286 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/AST/Decl.cpp b/lib/AST/Decl.cpp
index 1a7eeca..a831c4f 100644
--- a/lib/AST/Decl.cpp
+++ b/lib/AST/Decl.cpp
@@ -16,6 +16,8 @@
 #include "clang/AST/Attr.h"
 #include "clang/Basic/IdentifierTable.h"
 #include "llvm/ADT/DenseMap.h"
+
+#include <stdio.h>
 using namespace clang;
 
 //===----------------------------------------------------------------------===//
@@ -314,8 +316,10 @@
   DeclAttrMapTy::iterator it = DeclAttrs->find(this);
   assert(it != DeclAttrs->end() && "No attrs found but HasAttrs is true!");
 
-  delete it->second;
+  // FIXME: Properly release attributes.
+  // delete it->second;
   DeclAttrs->erase(it);
+  
   if (DeclAttrs->empty()) {
     delete DeclAttrs;
     DeclAttrs = 0;
@@ -366,47 +370,11 @@
 }
 
 
-#define CASE(KIND) \
-  case KIND: \
-    static_cast<KIND##Decl *>(const_cast<Decl *>(this))->~KIND##Decl(); \
-    break
-
-void Decl::Destroy(ASTContext& C) const {
-  switch (getKind()) {
-  CASE(TranslationUnit);
-  CASE(Field);
-  CASE(ObjCIvar);
-  CASE(ObjCCategory);
-  CASE(ObjCCategoryImpl);
-  CASE(ObjCImplementation);
-  CASE(ObjCProtocol);
-  CASE(ObjCProperty);
-  CASE(Namespace);
-  CASE(Typedef);
-  CASE(Enum);
-  CASE(EnumConstant);
-  CASE(Function);
-  CASE(Var);
-  CASE(ParmVar);
-  CASE(ObjCInterface);
-  CASE(ObjCCompatibleAlias);
-  CASE(ObjCMethod);
-  CASE(ObjCClass);
-  CASE(ObjCForwardProtocol);
-  CASE(LinkageSpec);
-
-  case Struct: case Union: case Class:
-    static_cast<RecordDecl *>(const_cast<Decl *>(this))->~RecordDecl();
-    break;
-
-  default: assert(0 && "Unknown decl kind!");
-  }
-
+void Decl::Destroy(ASTContext& C) {
+  this->~Decl();
   C.getAllocator().Deallocate((void *)this);
 }
 
-#undef CASE
-
 //===----------------------------------------------------------------------===//
 // DeclContext Implementation
 //===----------------------------------------------------------------------===//
@@ -442,10 +410,14 @@
 
 FunctionDecl::~FunctionDecl() {
   delete[] ParamInfo;
-  delete Body;
-  delete PreviousDeclaration;
 }
 
+void FunctionDecl::Destroy(ASTContext& C) {
+  if (Body) Body->Destroy(C);
+  Decl::Destroy(C);
+}
+
+
 Stmt *FunctionDecl::getBody(const FunctionDecl *&Definition) const {
   for (const FunctionDecl *FD = this; FD != 0; FD = FD->PreviousDeclaration) {
     if (FD->Body) {
diff --git a/lib/AST/Stmt.cpp b/lib/AST/Stmt.cpp
index ffc6c2e..993dda7 100644
--- a/lib/AST/Stmt.cpp
+++ b/lib/AST/Stmt.cpp
@@ -42,9 +42,14 @@
   return getStmtInfoTableEntry(sClass).Name;
 }
 
-void Stmt::DestroyChildren() {
+void Stmt::DestroyChildren(ASTContext& C) {
   for (child_iterator I = child_begin(), E = child_end(); I !=E; ++I)
-    delete *I; // Handles the case when *I == NULL.
+    if (Stmt* Child = *I) Child->Destroy(C);
+}
+
+void Stmt::Destroy(ASTContext& C) {
+  DestroyChildren(C);
+  this->~Stmt();
 }
 
 void Stmt::PrintStats() {
diff --git a/lib/AST/TranslationUnit.cpp b/lib/AST/TranslationUnit.cpp
index 5c043ef..9d77586 100644
--- a/lib/AST/TranslationUnit.cpp
+++ b/lib/AST/TranslationUnit.cpp
@@ -20,9 +20,9 @@
 #include "llvm/Bitcode/Deserialize.h"
 #include "llvm/Support/MemoryBuffer.h"
 #include "llvm/System/Path.h"
-#include "llvm/ADT/OwningPtr.h"
 
-#include <stdio.h>
+#include "llvm/ADT/OwningPtr.h"
+#include "llvm/ADT/DenseSet.h"
 
 using namespace clang;
 
@@ -31,8 +31,15 @@
        DeclsBlock = 3 };
 
 TranslationUnit::~TranslationUnit() {
-  for (iterator I=begin(), E=end(); I!=E; ++I) 
+  
+  llvm::DenseSet<Decl*> Killed;
+  
+  for (iterator I=begin(), E=end(); I!=E; ++I) {
+    if (Killed.count(*I)) continue;
+
+    Killed.insert(*I);
     (*I)->Destroy(*Context);
+  }
   
   if (OwnsMetaData && Context) {
     // The ASTContext object has the sole references to the IdentifierTable
diff --git a/lib/Sema/ParseAST.cpp b/lib/Sema/ParseAST.cpp
index 364b072..fcdc27b 100644
--- a/lib/Sema/ParseAST.cpp
+++ b/lib/Sema/ParseAST.cpp
@@ -14,6 +14,7 @@
 #include "clang/Sema/ParseAST.h"
 #include "clang/AST/ASTContext.h"
 #include "clang/AST/ASTConsumer.h"
+#include "clang/AST/TranslationUnit.h"
 #include "Sema.h"
 #include "clang/Parse/Action.h"
 #include "clang/Parse/Parser.h"
@@ -36,6 +37,8 @@
   ASTContext Context(PP.getSourceManager(), PP.getTargetInfo(),
                      PP.getIdentifierTable(), PP.getSelectorTable());
   
+  TranslationUnit TU(Context, PP.getLangOptions());
+  
   Parser P(PP, *new Sema(PP, Context, *Consumer));
   PP.EnterMainSourceFile();
     
@@ -45,12 +48,16 @@
   Consumer->Initialize(Context);
   
   Parser::DeclTy *ADecl;
+  
   while (!P.ParseTopLevelDecl(ADecl)) {  // Not end of file.
     // If we got a null return and something *was* parsed, ignore it.  This
     // is due to a top-level semicolon, an action override, or a parse error
     // skipping something.
-    if (ADecl)
-      Consumer->HandleTopLevelDecl(static_cast<Decl*>(ADecl));
+    if (ADecl) {
+      Decl* D = static_cast<Decl*>(ADecl);      
+      TU.AddTopLevelDecl(D); // TranslationUnit now owns the Decl.
+      Consumer->HandleTopLevelDecl(D);
+    }
   };
 
   if (PrintStats) {