commit c63d2c8469d6b96712b324f76b4af07e1852313f
author Douglas Gregor <dgregor@apple.com> Wed May 12 16:39:35 2010 +0000
committer Douglas Gregor <dgregor@apple.com> Wed May 12 16:39:35 2010 +0000
tree 5dadce03297f0232292d330f080f6b9346b1c1be
parent a9f1bb19f75871481aa66316902bb10f4669e596

When we emit an error during the implicit definition of a special
member function (default constructor, copy constructor, copy
assignment operator, destructor), emit a note showing where that
implicit definition was required.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@103619 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Sema/Sema.h

diff --git a/lib/Sema/Sema.h b/lib/Sema/Sema.h
index fa8976f..70e445f 100644
--- a/lib/Sema/Sema.h
+++ b/lib/Sema/Sema.h
@@ -3572,6 +3572,24 @@
     }
   };
 
+  /// \brief RAII class that determines when any errors have occurred
+  /// between the time the instance was created and the time it was
+  /// queried.
+  class ErrorTrap {
+    Sema &SemaRef;
+    unsigned PrevErrors;
+
+  public:
+    explicit ErrorTrap(Sema &SemaRef)
+      : SemaRef(SemaRef), PrevErrors(SemaRef.getDiagnostics().getNumErrors()) {}
+
+    /// \brief Determine whether any errors have occurred since this
+    /// object instance was created.
+    bool hasErrorOccurred() const {
+      return SemaRef.getDiagnostics().getNumErrors() > PrevErrors;
+    }
+  };
+
   /// \brief A stack-allocated class that identifies which local
   /// variable declaration instantiations are present in this scope.
   ///

lib/Sema/SemaDeclCXX.cpp

diff --git a/lib/Sema/SemaDeclCXX.cpp b/lib/Sema/SemaDeclCXX.cpp
index 72a57c3..7320bc6 100644
--- a/lib/Sema/SemaDeclCXX.cpp
+++ b/lib/Sema/SemaDeclCXX.cpp
@@ -4146,12 +4146,15 @@
   assert(ClassDecl && "DefineImplicitDefaultConstructor - invalid constructor");
 
   ImplicitlyDefinedFunctionScope Scope(*this, Constructor);
-  if (SetBaseOrMemberInitializers(Constructor, 0, 0, /*AnyErrors=*/false)) {
+  ErrorTrap Trap(*this);
+  if (SetBaseOrMemberInitializers(Constructor, 0, 0, /*AnyErrors=*/false) ||
+      Trap.hasErrorOccurred()) {
     Diag(CurrentLocation, diag::note_member_synthesized_at) 
       << CXXConstructor << Context.getTagDeclType(ClassDecl);
     Constructor->setInvalidDecl();
   } else {
     Constructor->setUsed();
+    MaybeMarkVirtualMembersReferenced(CurrentLocation, Constructor);
   }
 }
 
@@ -4162,14 +4165,16 @@
   CXXRecordDecl *ClassDecl = Destructor->getParent();
   assert(ClassDecl && "DefineImplicitDestructor - invalid destructor");
 
+  if (Destructor->isInvalidDecl())
+    return;
+
   ImplicitlyDefinedFunctionScope Scope(*this, Destructor);
 
+  ErrorTrap Trap(*this);
   MarkBaseAndMemberDestructorsReferenced(Destructor->getLocation(),
                                          Destructor->getParent());
 
-  // FIXME: If CheckDestructor fails, we should emit a note about where the
-  // implicit destructor was needed.
-  if (CheckDestructor(Destructor)) {
+  if (CheckDestructor(Destructor) || Trap.hasErrorOccurred()) {
     Diag(CurrentLocation, diag::note_member_synthesized_at) 
       << CXXDestructor << Context.getTagDeclType(ClassDecl);
 
@@ -4178,6 +4183,7 @@
   }
 
   Destructor->setUsed();
+  MaybeMarkVirtualMembersReferenced(CurrentLocation, Destructor);
 }
 
 /// \brief Builds a statement that copies the given entity from \p From to
@@ -4396,6 +4402,7 @@
   CopyAssignOperator->setUsed();
 
   ImplicitlyDefinedFunctionScope Scope(*this, CopyAssignOperator);
+  ErrorTrap Trap(*this);
 
   // C++0x [class.copy]p30:
   //   The implicitly-defined or explicitly-defaulted copy assignment operator
@@ -4616,6 +4623,12 @@
       Invalid = true;
     else {
       Statements.push_back(Return.takeAs<Stmt>());
+
+      if (Trap.hasErrorOccurred()) {
+        Diag(CurrentLocation, diag::note_member_synthesized_at) 
+          << CXXCopyAssignment << Context.getTagDeclType(ClassDecl);
+        Invalid = true;
+      }
     }
   }
 
@@ -4628,6 +4641,8 @@
                                             /*isStmtExpr=*/false);
   assert(!Body.isInvalid() && "Compound statement creation cannot fail");
   CopyAssignOperator->setBody(Body.takeAs<Stmt>());
+
+  MaybeMarkVirtualMembersReferenced(CurrentLocation, CopyAssignOperator);
 }
 
 void Sema::DefineImplicitCopyConstructor(SourceLocation CurrentLocation,
@@ -4642,8 +4657,10 @@
   assert(ClassDecl && "DefineImplicitCopyConstructor - invalid constructor");
 
   ImplicitlyDefinedFunctionScope Scope(*this, CopyConstructor);
+  ErrorTrap Trap(*this);
 
-  if (SetBaseOrMemberInitializers(CopyConstructor, 0, 0, /*AnyErrors=*/false)) {
+  if (SetBaseOrMemberInitializers(CopyConstructor, 0, 0, /*AnyErrors=*/false) ||
+      Trap.hasErrorOccurred()) {
     Diag(CurrentLocation, diag::note_member_synthesized_at) 
       << CXXCopyConstructor << Context.getTagDeclType(ClassDecl);
     CopyConstructor->setInvalidDecl();
@@ -4653,6 +4670,7 @@
                                                MultiStmtArg(*this, 0, 0), 
                                                /*isStmtExpr=*/false)
                                                               .takeAs<Stmt>());
+    MaybeMarkVirtualMembersReferenced(CurrentLocation, CopyConstructor);
   }
   
   CopyConstructor->setUsed();