From: Nick Lewycky <nicholas@mxc.ca>
Date: Tue, 6 Jul 2010 19:51:49 +0000 (+0000)
Subject: Fix multiple emission of the this-> fixit for each instantiation by fixing the
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=03d98c5d592d74ae97aa3f93f80441b64960e4b6;p=clang

Fix multiple emission of the this-> fixit for each instantiation by fixing the
AST during the instantiation. Fixes PR7417!


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@107690 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Sema/Sema.h b/lib/Sema/Sema.h
index c8294109fc..cbbaa1d64e 100644
--- a/lib/Sema/Sema.h
+++ b/lib/Sema/Sema.h
@@ -2793,6 +2793,7 @@ public:
                                          const CXXMethodDecl *Old);
 
   bool CheckPureMethod(CXXMethodDecl *Method, SourceRange InitRange);
+
   //===--------------------------------------------------------------------===//
   // C++ Access Control
   //
@@ -3562,6 +3563,12 @@ public:
   /// to implement it anywhere else.
   ActiveTemplateInstantiation LastTemplateInstantiationErrorContext;
 
+  /// \brief The stack of calls expression undergoing template instantiation.
+  ///
+  /// The top of this stack is used by a fixit instantiating unresolved
+  /// function calls to fix the AST to match the textual change it prints.
+  llvm::SmallVector<CallExpr *, 8> CallsUndergoingInstantiation;
+
   /// \brief A stack object to be created when performing template
   /// instantiation.
   ///
diff --git a/lib/Sema/SemaExpr.cpp b/lib/Sema/SemaExpr.cpp
index bfcf25fb94..8b7c689ae2 100644
--- a/lib/Sema/SemaExpr.cpp
+++ b/lib/Sema/SemaExpr.cpp
@@ -869,8 +869,8 @@ static void DiagnoseInstanceReference(Sema &SemaRef,
 /// Diagnose an empty lookup.
 ///
 /// \return false if new lookup candidates were found
-bool Sema::DiagnoseEmptyLookup(Scope *S, CXXScopeSpec &SS,
-                               LookupResult &R, CorrectTypoContext CTC) {
+bool Sema::DiagnoseEmptyLookup(Scope *S, CXXScopeSpec &SS, LookupResult &R,
+                               CorrectTypoContext CTC) {
   DeclarationName Name = R.getLookupName();
 
   unsigned diagnostic = diag::err_undeclared_var_use;
@@ -886,7 +886,7 @@ bool Sema::DiagnoseEmptyLookup(Scope *S, CXXScopeSpec &SS,
   // unqualified lookup.  This is useful when (for example) the
   // original lookup would not have found something because it was a
   // dependent name.
-  for (DeclContext *DC = SS.isEmpty()? CurContext : 0;
+  for (DeclContext *DC = SS.isEmpty() ? CurContext : 0;
        DC; DC = DC->getParent()) {
     if (isa<CXXRecordDecl>(DC)) {
       LookupQualifiedName(R, DC);
@@ -903,11 +903,29 @@ bool Sema::DiagnoseEmptyLookup(Scope *S, CXXScopeSpec &SS,
         // Give a code modification hint to insert 'this->'.
         // TODO: fixit for inserting 'Base<T>::' in the other cases.
         // Actually quite difficult!
-        if (isInstance)
+        if (isInstance) {
           Diag(R.getNameLoc(), diagnostic) << Name
             << FixItHint::CreateInsertion(R.getNameLoc(), "this->");
-        else
+
+          UnresolvedLookupExpr *ULE = cast<UnresolvedLookupExpr>(
+              CallsUndergoingInstantiation.back()->getCallee());
+          CXXMethodDecl *DepMethod = cast<CXXMethodDecl>(
+              CurMethod->getInstantiatedFromMemberFunction());
+          QualType DepThisType = DepMethod->getThisType(Context);
+          CXXThisExpr *DepThis = new (Context) CXXThisExpr(R.getNameLoc(),
+                                                           DepThisType, false);
+          TemplateArgumentListInfo TList;
+          if (ULE->hasExplicitTemplateArgs())
+            ULE->copyTemplateArgumentsInto(TList);
+          CXXDependentScopeMemberExpr *DepExpr =
+              CXXDependentScopeMemberExpr::Create(
+                  Context, DepThis, DepThisType, true, SourceLocation(),
+                  ULE->getQualifier(), ULE->getQualifierRange(), NULL, Name,
+                  R.getNameLoc(), &TList);
+          CallsUndergoingInstantiation.back()->setCallee(DepExpr);
+        } else {
           Diag(R.getNameLoc(), diagnostic) << Name;
+        }
 
         // Do we really want to note all of these?
         for (LookupResult::iterator I = R.begin(), E = R.end(); I != E; ++I)
diff --git a/lib/Sema/SemaTemplateInstantiate.cpp b/lib/Sema/SemaTemplateInstantiate.cpp
index cc9f600215..9e454bc0f2 100644
--- a/lib/Sema/SemaTemplateInstantiate.cpp
+++ b/lib/Sema/SemaTemplateInstantiate.cpp
@@ -620,6 +620,14 @@ namespace {
     QualType TransformTemplateTypeParmType(TypeLocBuilder &TLB,
                                            TemplateTypeParmTypeLoc TL,
                                            QualType ObjectType);
+
+    Sema::OwningExprResult TransformCallExpr(CallExpr *CE) {
+      getSema().CallsUndergoingInstantiation.push_back(CE);
+      OwningExprResult Result =
+          TreeTransform<TemplateInstantiator>::TransformCallExpr(CE);
+      getSema().CallsUndergoingInstantiation.pop_back();
+      return move(Result);
+    }
   };
 }