[CUDA] Destroy deferred diagnostics before destroying the ASTContext's PartialDiagnostic allocator.

[jlebar]

Summary

This will let us (in a separate patch) allocate deferred diagnostics in
the ASTContext's PartialDiagnostic arena.

[rnk]

clang/lib/CodeGen/CodeGenModule.cpp

512–513 ↗

(On Diff #73575)

The ASTContext outlives CodeGenModule, but the diagnostic allocator in the ASTContext does not. As written, this suggests that CGM outlives ASTContext, which isn't right.

[jlebar]

Update comment.

[rnk]

lgtm

cfe/trunk/include/clang/AST/ASTContext.h

class ASTContext : public RefCountedBase<ASTContext> {
   struct PerModuleInitializers {
     llvm::SmallVector<Decl*, 4> Initializers;
     llvm::SmallVector<uint32_t, 4> LazyInitializers;
 
     void resolve(ASTContext &Ctx);
   };
   llvm::DenseMap<Module*, PerModuleInitializers*> ModuleInitializers;
 
-  /// Diagnostics that are emitted if and only if the given function is
-  /// codegen'ed.  Access these through FunctionDecl::addDeferredDiag() and
-  /// FunctionDecl::takeDeferredDiags().
-  llvm::DenseMap<const FunctionDecl *, std::vector<PartialDiagnosticAt>>
-      DeferredDiags;
-
 public:
   /// \brief A type synonym for the TemplateOrInstantiation mapping.
   typedef llvm::PointerUnion<VarTemplateDecl *, MemberSpecializationInfo *>
   TemplateOrSpecializationInfo;
 
 private:
 
   /// \brief A mapping to contain the template or declaration that
private:
   ///
   /// AST objects are never destructed; rather, all memory associated with the
   /// AST objects will be released when the ASTContext itself is destroyed.
   mutable llvm::BumpPtrAllocator BumpAlloc;
 
   /// \brief Allocator for partial diagnostics.
   PartialDiagnostic::StorageAllocator DiagAllocator;
 
+  /// Diagnostics that are emitted if and only if the given function is
+  /// codegen'ed.  Access these through FunctionDecl::addDeferredDiag() and
+  /// FunctionDecl::takeDeferredDiags().
+  llvm::DenseMap<const FunctionDecl *, std::vector<PartialDiagnosticAt>>
+      DeferredDiags;
+
   /// \brief The current C++ ABI.
   std::unique_ptr<CXXABI> ABI;
   CXXABI *createCXXABI(const TargetInfo &T);
 
   /// \brief The logical -> physical address space map.
   const LangAS::Map *AddrSpaceMap;
 
   /// \brief Address space map mangling must be used with language specific 

cfe/trunk/lib/CodeGen/CodeGenModule.cpp

void CodeGenModule::Release() {
   // when we first discovered them because that would have halted codegen,
   // preventing us from gathering other deferred diags.
   for (const PartialDiagnosticAt &DiagAt : DeferredDiags) {
     SourceLocation Loc = DiagAt.first;
     const PartialDiagnostic &PD = DiagAt.second;
     DiagnosticBuilder Builder(getDiags().Report(Loc, PD.getDiagID()));
     PD.Emit(Builder);
   }
+  // Clear the deferred diags so they don't outlive the ASTContext's
+  // PartialDiagnostic allocator.
+  DeferredDiags.clear();
 }
 
 void CodeGenModule::UpdateCompletedType(const TagDecl *TD) {
   // Make sure that this type is translated.
   Types.UpdateCompletedType(TD);
 }
 
 void CodeGenModule::RefreshTypeCacheForClass(const CXXRecordDecl *RD) {