From: George Burgess IV <george.burgess.iv@gmail.com>
Date: Tue, 14 Feb 2017 05:37:36 +0000 (+0000)
Subject: Add a destruct-on-exit function to ASTContext.
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=0b0a12c5693701cc54458d3c3981850547a9840e;p=clang

Add a destruct-on-exit function to ASTContext.

It looks like the only use of AddDeallocation is to indirectly call the
destructors of objects. In one case I found
(TypeAliasTemplateDecl::Common), the destructor is a nop, so registering
it to run later seems pointless.

All of the other *::Common types have non-trivial dtors, so deleting the
useless AddDeallocation felt somewhat fragile. Happy to kill it + turn
the is_trivial_dtor check into a static_assert if people think that'd be
better.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@295029 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/include/clang/AST/ASTContext.h b/include/clang/AST/ASTContext.h
index 6811281570..4366b79c1c 100644
--- a/include/clang/AST/ASTContext.h
+++ b/include/clang/AST/ASTContext.h
@@ -66,6 +66,7 @@
 #include <memory>
 #include <new>
 #include <string>
+#include <type_traits>
 #include <utility>
 #include <vector>
 
@@ -2487,6 +2488,16 @@ public:
   /// when it is called.
   void AddDeallocation(void (*Callback)(void*), void *Data);
 
+  /// If T isn't trivially destructible, calls AddDeallocation to register it
+  /// for destruction.
+  template <typename T>
+  void addDestruction(T *Ptr) {
+    if (!std::is_trivially_destructible<T>::value) {
+      auto DestroyPtr = [](void *V) { static_cast<T *>(V)->~T(); };
+      AddDeallocation(DestroyPtr, Ptr);
+    }
+  }
+
   GVALinkage GetGVALinkageForFunction(const FunctionDecl *FD) const;
   GVALinkage GetGVALinkageForVariable(const VarDecl *VD);
 
diff --git a/include/clang/AST/DeclTemplate.h b/include/clang/AST/DeclTemplate.h
index 6f81fcb4ad..e83ec3cfcf 100644
--- a/include/clang/AST/DeclTemplate.h
+++ b/include/clang/AST/DeclTemplate.h
@@ -937,8 +937,6 @@ SpecEntryTraits<FunctionTemplateSpecializationInfo> {
 
 /// Declaration of a template function.
 class FunctionTemplateDecl : public RedeclarableTemplateDecl {
-  static void DeallocateCommon(void *Ptr);
-
 protected:
   /// \brief Data that is common to all of the declarations of a given
   /// function template.
@@ -2035,8 +2033,6 @@ public:
 
 /// Declaration of a class template.
 class ClassTemplateDecl : public RedeclarableTemplateDecl {
-  static void DeallocateCommon(void *Ptr);
-
 protected:
   /// \brief Data that is common to all of the declarations of a given
   /// class template.
@@ -2330,8 +2326,6 @@ public:
 /// template \<typename T> using V = std::map<T*, int, MyCompare<T>>;
 /// \endcode
 class TypeAliasTemplateDecl : public RedeclarableTemplateDecl {
-  static void DeallocateCommon(void *Ptr);
-
 protected:
   typedef CommonBase Common;
 
@@ -2856,8 +2850,6 @@ public:
 
 /// Declaration of a variable template.
 class VarTemplateDecl : public RedeclarableTemplateDecl {
-  static void DeallocateCommon(void *Ptr);
-
 protected:
   /// \brief Data that is common to all of the declarations of a given
   /// variable template.
diff --git a/lib/AST/Decl.cpp b/lib/AST/Decl.cpp
index 81f08787d5..2927199506 100644
--- a/lib/AST/Decl.cpp
+++ b/lib/AST/Decl.cpp
@@ -2143,13 +2143,6 @@ APValue *VarDecl::evaluateValue() const {
   return evaluateValue(Notes);
 }
 
-namespace {
-// Destroy an APValue that was allocated in an ASTContext.
-void DestroyAPValue(void* UntypedValue) {
-  static_cast<APValue*>(UntypedValue)->~APValue();
-}
-} // namespace
-
 APValue *VarDecl::evaluateValue(
     SmallVectorImpl<PartialDiagnosticAt> &Notes) const {
   EvaluatedStmt *Eval = ensureEvaluatedStmt();
@@ -2181,7 +2174,7 @@ APValue *VarDecl::evaluateValue(
   if (!Result)
     Eval->Evaluated = APValue();
   else if (Eval->Evaluated.needsCleanup())
-    getASTContext().AddDeallocation(DestroyAPValue, &Eval->Evaluated);
+    getASTContext().addDestruction(&Eval->Evaluated);
 
   Eval->IsEvaluating = false;
   Eval->WasEvaluated = true;
diff --git a/lib/AST/DeclTemplate.cpp b/lib/AST/DeclTemplate.cpp
index 22f6e18d56..00a6739478 100644
--- a/lib/AST/DeclTemplate.cpp
+++ b/lib/AST/DeclTemplate.cpp
@@ -208,10 +208,6 @@ void RedeclarableTemplateDecl::addSpecializationImpl(
 // FunctionTemplateDecl Implementation
 //===----------------------------------------------------------------------===//
 
-void FunctionTemplateDecl::DeallocateCommon(void *Ptr) {
-  static_cast<Common *>(Ptr)->~Common();
-}
-
 FunctionTemplateDecl *FunctionTemplateDecl::Create(ASTContext &C,
                                                    DeclContext *DC,
                                                    SourceLocation L,
@@ -231,7 +227,7 @@ FunctionTemplateDecl *FunctionTemplateDecl::CreateDeserialized(ASTContext &C,
 RedeclarableTemplateDecl::CommonBase *
 FunctionTemplateDecl::newCommon(ASTContext &C) const {
   Common *CommonPtr = new (C) Common;
-  C.AddDeallocation(DeallocateCommon, CommonPtr);
+  C.addDestruction(CommonPtr);
   return CommonPtr;
 }
 
@@ -288,10 +284,6 @@ ArrayRef<TemplateArgument> FunctionTemplateDecl::getInjectedTemplateArgs() {
 // ClassTemplateDecl Implementation
 //===----------------------------------------------------------------------===//
 
-void ClassTemplateDecl::DeallocateCommon(void *Ptr) {
-  static_cast<Common *>(Ptr)->~Common();
-}
-
 ClassTemplateDecl *ClassTemplateDecl::Create(ASTContext &C,
                                              DeclContext *DC,
                                              SourceLocation L,
@@ -348,7 +340,7 @@ ClassTemplateDecl::getPartialSpecializations() {
 RedeclarableTemplateDecl::CommonBase *
 ClassTemplateDecl::newCommon(ASTContext &C) const {
   Common *CommonPtr = new (C) Common;
-  C.AddDeallocation(DeallocateCommon, CommonPtr);
+  C.addDestruction(CommonPtr);
   return CommonPtr;
 }
 
@@ -888,13 +880,10 @@ TypeAliasTemplateDecl *TypeAliasTemplateDecl::CreateDeserialized(ASTContext &C,
                                            DeclarationName(), nullptr, nullptr);
 }
 
-void TypeAliasTemplateDecl::DeallocateCommon(void *Ptr) {
-  static_cast<Common *>(Ptr)->~Common();
-}
 RedeclarableTemplateDecl::CommonBase *
 TypeAliasTemplateDecl::newCommon(ASTContext &C) const {
   Common *CommonPtr = new (C) Common;
-  C.AddDeallocation(DeallocateCommon, CommonPtr);
+  C.addDestruction(CommonPtr);
   return CommonPtr;
 }
 
@@ -915,10 +904,6 @@ ClassScopeFunctionSpecializationDecl::CreateDeserialized(ASTContext &C,
 // VarTemplateDecl Implementation
 //===----------------------------------------------------------------------===//
 
-void VarTemplateDecl::DeallocateCommon(void *Ptr) {
-  static_cast<Common *>(Ptr)->~Common();
-}
-
 VarTemplateDecl *VarTemplateDecl::getDefinition() {
   VarTemplateDecl *CurD = this;
   while (CurD) {
@@ -974,7 +959,7 @@ VarTemplateDecl::getPartialSpecializations() {
 RedeclarableTemplateDecl::CommonBase *
 VarTemplateDecl::newCommon(ASTContext &C) const {
   Common *CommonPtr = new (C) Common;
-  C.AddDeallocation(DeallocateCommon, CommonPtr);
+  C.addDestruction(CommonPtr);
   return CommonPtr;
 }