Fix regression in r154844. If necessary, defer computing adjusted destructor

exception specifications in C++11 until after we've parsed the exception
specifications for nested classes.

llvm-svn: 155293

clang/include/clang/Sema/Sema.h

@@ -331,6 +331,11 @@ public:
   /// cycle detection at the end of the TU.
   DelegatingCtorDeclsType DelegatingCtorDecls;
 
+  /// \brief All the destructors seen during a class definition that had their
+  /// exception spec computation delayed because it depended on an unparsed
+  /// exception spec.
+  SmallVector<CXXDestructorDecl*, 2> DelayedDestructorExceptionSpecs;
+
   /// \brief All the overriding destructors seen during a class definition
   /// (there could be multiple due to nested classes) that had their exception
   /// spec checks delayed, plus the overridden destructor.
@@ -3203,7 +3208,8 @@ public:
   /// C++11 says that user-defined destructors with no exception spec get one
   /// that looks as if the destructor was implicitly declared.
   void AdjustDestructorExceptionSpec(CXXRecordDecl *ClassDecl,
-                                     CXXDestructorDecl *Destructor);
+                                     CXXDestructorDecl *Destructor,
+                                     bool WasDelayed = false);
 
   /// \brief Declare all inherited constructors for the given class.
   ///
@@ -4048,6 +4054,7 @@ public:
                                          SourceLocation LBrac,
                                          SourceLocation RBrac,
                                          AttributeList *AttrList);
+  void ActOnFinishCXXMemberDecls();
 
   void ActOnReenterTemplateScope(Scope *S, Decl *Template);
   void ActOnReenterDeclaratorTemplateScope(Scope *S, DeclaratorDecl *D);

clang/lib/Parse/ParseDeclCXX.cpp

@@ -2369,6 +2369,10 @@ void Parser::ParseCXXMemberSpecification(SourceLocation RecordLoc,
     SourceLocation SavedPrevTokLocation = PrevTokLocation;
     ParseLexedAttributes(getCurrentClass());
     ParseLexedMethodDeclarations(getCurrentClass());
+
+    // We've finished with all pending member declarations.
+    Actions.ActOnFinishCXXMemberDecls();
+
     ParseLexedMemberInitializers(getCurrentClass());
     ParseLexedMethodDefs(getCurrentClass());
     PrevTokLocation = SavedPrevTokLocation;

clang/lib/Sema/SemaDecl.cpp

@@ -9784,21 +9784,6 @@ void Sema::ActOnFields(Scope* S,
     if (!Completed)
       Record->completeDefinition();
 
-    // Now that the record is complete, do any delayed exception spec checks
-    // we were missing.
-    while (!DelayedDestructorExceptionSpecChecks.empty()) {
-      const CXXDestructorDecl *Dtor =
-              DelayedDestructorExceptionSpecChecks.back().first;
-      if (Dtor->getParent() != Record)
-        break;
-
-      assert(!Dtor->getParent()->isDependentType() &&
-          "Should not ever add destructors of templates into the list.");
-      CheckOverridingFunctionExceptionSpec(Dtor,
-          DelayedDestructorExceptionSpecChecks.back().second);
-      DelayedDestructorExceptionSpecChecks.pop_back();
-    }
-
   } else {
     ObjCIvarDecl **ClsFields =
       reinterpret_cast<ObjCIvarDecl**>(RecFields.data());

clang/lib/Sema/SemaDeclCXX.cpp

@@ -7317,15 +7317,42 @@ void Sema::DefineImplicitDestructor(SourceLocation CurrentLocation,
   }
 }
 
+/// \brief Perform any semantic analysis which needs to be delayed until all
+/// pending class member declarations have been parsed.
+void Sema::ActOnFinishCXXMemberDecls() {
+  // Now we have parsed all exception specifications, determine the implicit
+  // exception specifications for destructors.
+  for (unsigned i = 0, e = DelayedDestructorExceptionSpecs.size();
+       i != e; ++i) {
+    CXXDestructorDecl *Dtor = DelayedDestructorExceptionSpecs[i];
+    AdjustDestructorExceptionSpec(Dtor->getParent(), Dtor, true);
+  }
+  DelayedDestructorExceptionSpecs.clear();
+
+  // Perform any deferred checking of exception specifications for virtual
+  // destructors.
+  for (unsigned i = 0, e = DelayedDestructorExceptionSpecChecks.size();
+       i != e; ++i) {
+    const CXXDestructorDecl *Dtor =
+        DelayedDestructorExceptionSpecChecks[i].first;
+    assert(!Dtor->getParent()->isDependentType() &&
+           "Should not ever add destructors of templates into the list.");
+    CheckOverridingFunctionExceptionSpec(Dtor,
+        DelayedDestructorExceptionSpecChecks[i].second);
+  }
+  DelayedDestructorExceptionSpecChecks.clear();
+}
+
 void Sema::AdjustDestructorExceptionSpec(CXXRecordDecl *classDecl,
-                                         CXXDestructorDecl *destructor) {
+                                         CXXDestructorDecl *destructor,
+                                         bool WasDelayed) {
   // C++11 [class.dtor]p3:
   //   A declaration of a destructor that does not have an exception-
   //   specification is implicitly considered to have the same exception-
   //   specification as an implicit declaration.
   const FunctionProtoType *dtorType = destructor->getType()->
                                         getAs<FunctionProtoType>();
-  if (dtorType->hasExceptionSpec())
+  if (!WasDelayed && dtorType->hasExceptionSpec())
     return;
 
   ImplicitExceptionSpecification exceptSpec =
@@ -7342,6 +7369,14 @@ void Sema::AdjustDestructorExceptionSpec(CXXRecordDecl *classDecl,
 
   destructor->setType(ty);
 
+  // If we can't compute the exception specification for this destructor yet
+  // (because it depends on an exception specification which we have not parsed
+  // yet), make a note that we need to try again when the class is complete.
+  if (epi.ExceptionSpecType == EST_Delayed) {
+    assert(!WasDelayed && "couldn't compute destructor exception spec");
+    DelayedDestructorExceptionSpecs.push_back(destructor);
+  }
+
   // FIXME: If the destructor has a body that could throw, and the newly created
   // spec doesn't allow exceptions, we should emit a warning, because this
   // change in behavior can break conforming C++03 programs at runtime.

clang/test/SemaCXX/implicit-exception-spec.cpp

@@ -54,3 +54,33 @@ namespace DefaultArgument {
     } t; // expected-note {{has no default constructor}}
   };
 }
+
+namespace ImplicitDtorExceptionSpec {
+  struct A {
+    virtual ~A();
+
+    struct Inner {
+      ~Inner() throw();
+    };
+    Inner inner;
+  };
+
+  struct B {
+    virtual ~B() {} // expected-note {{here}}
+  };
+
+  struct C : B {
+    virtual ~C() {}
+    A a;
+  };
+
+  struct D : B {
+    ~D(); // expected-error {{more lax than base}}
+    struct E {
+      ~E();
+      struct F {
+        ~F() throw(A);
+      } f;
+    } e;
+  };
+}