[PATCH] D43547: [NameMangling] Make ASTContext owning the ManglingContext during entire compilation

[Michael Haidl via Phabricator via cfe-commits]

pacxx created this revision.
pacxx added reviewers: rnk, rsmith.
Herald added a subscriber: cfe-commits.

The ASTContext is only used to create a Mangling Context and forwards ownership to everyone who requests a ManglingContext.

The problem fixed by this commit is located in the handling of the __FUNCDNAME__ generation. Every time a __FUNCDNAME__ expression is handled a new ManglingContext is created. The MC and its cached manglings are thrown away every time the __FUNCDNAME__ was handled which results in wrong numbering of lambda expressions in name manglings (every lambda gets id 0) what again leads to inconsistencies between __FUNCDNAME__ and the name manglings in the generated code.


Repository:
  rC Clang

https://reviews.llvm.org/D43547

Files:
  include/clang/AST/ASTContext.h
  lib/AST/ASTContext.cpp
  lib/Index/CodegenNameGenerator.cpp


Index: lib/Index/CodegenNameGenerator.cpp
===================================================================
--- lib/Index/CodegenNameGenerator.cpp
+++ lib/Index/CodegenNameGenerator.cpp
@@ -26,11 +26,11 @@
 using namespace clang::index;
 
 struct CodegenNameGenerator::Implementation {
-  std::unique_ptr<MangleContext> MC;
+  MangleContext& MC;
   llvm::DataLayout DL;
 
   Implementation(ASTContext &Ctx)
-    : MC(Ctx.createMangleContext()),
+    : MC(Ctx.getMangleContext()),
       DL(Ctx.getTargetInfo().getDataLayout()) {}
 
   bool writeName(const Decl *D, raw_ostream &OS) {
@@ -106,7 +106,6 @@
     const NamedDecl *ND = cast<NamedDecl>(D);
 
     ASTContext &Ctx = ND->getASTContext();
-    std::unique_ptr<MangleContext> M(Ctx.createMangleContext());
 
     std::vector<std::string> Manglings;
 
Index: lib/AST/ASTContext.cpp
===================================================================
--- lib/AST/ASTContext.cpp
+++ lib/AST/ASTContext.cpp
@@ -9570,6 +9570,12 @@
   llvm_unreachable("Unsupported ABI");
 }
 
+MangleContext &ASTContext::getMangleContext() {
+  if (!MContext)
+    MContext.reset(createMangleContext());
+  return *MContext.get();
+}
+
 CXXABI::~CXXABI() = default;
 
 size_t ASTContext::getSideTableAllocatedMemory() const {
Index: include/clang/AST/ASTContext.h
===================================================================
--- include/clang/AST/ASTContext.h
+++ include/clang/AST/ASTContext.h
@@ -2158,6 +2158,7 @@
   VTableContextBase *getVTableContext();
 
   MangleContext *createMangleContext();
+  MangleContext &getMangleContext();
 
   void DeepCollectObjCIvars(const ObjCInterfaceDecl *OI, bool leafClass,
                             SmallVectorImpl<const ObjCIvarDecl*> &Ivars) const;
@@ -2828,6 +2829,7 @@
   std::unique_ptr<ParentMapOtherNodes> OtherParents;
 
   std::unique_ptr<VTableContextBase> VTContext;
+  std::unique_ptr<MangleContext> MContext;
 
   void ReleaseDeclContextMaps();
   void ReleaseParentMapEntries();


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