Implement declaration merging for typedefs loaded from disjoint

modules, so long as the typedefs refer to the same underlying
type. This ensures that the typedefs end up in the same redeclaration
chain.

To test this, fix name lookup for C/Objective-C to properly deal with
multiple declarations with the same name in the same scope.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@147533 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Sema/SemaLookup.cpp b/lib/Sema/SemaLookup.cpp
index 48ae1b970ddabc44c4aa0439f73e63c634232dd7..ae950ff27aa7bd692bb5276be0a3ef0496174cbc 100644 (file)
--- a/lib/Sema/SemaLookup.cpp
+++ b/lib/Sema/SemaLookup.cpp
@@ -1179,29 +1179,28 @@ bool Sema::LookupName(LookupResult &R, Scope *S, bool AllowBuiltinCreation) {
 
         // Check whether there are any other declarations with the same name
         // and in the same scope.
+        if (I != IEnd) {
+          DeclContext *DC = (*I)->getDeclContext()->getRedeclContext();
+          IdentifierResolver::iterator LastI = I;
+          for (++LastI; LastI != IEnd; ++LastI) {
+            DeclContext *LastDC 
+              = (*LastI)->getDeclContext()->getRedeclContext();
+            if (!(*LastI)->isInIdentifierNamespace(IDNS))
+              continue;
+            
+            if (!LastDC->Equals(DC))
+              break;
+            
+            if (!LastDC->isFileContext() && !S->isDeclScope(*LastI))
+              break;
+            
+            D = R.isForRedeclaration()? *LastI : getVisibleDecl(*LastI);
+            if (D)
+              R.addDecl(D);
+          }
 
-        // Figure out what scope the identifier is in.
-        while (S->getParent() &&
-               (!(S->getFlags() & Scope::DeclScope) ||
-                !S->isDeclScope(*I)))
-          S = S->getParent();
-
-        // Find the last declaration in this scope (with the same
-        // name, naturally).
-        IdentifierResolver::iterator LastI = I;
-        for (++LastI; LastI != IEnd; ++LastI) {
-          if (!S->isDeclScope(*LastI))
-            break;
-          
-          if (!(*LastI)->isInIdentifierNamespace(IDNS))
-            continue;
-          
-          D = R.isForRedeclaration()? *LastI : getVisibleDecl(*LastI);
-          if (D)
-            R.addDecl(D);
+          R.resolveKind();
         }
-
-        R.resolveKind();
         return true;
       }
   } else {

diff --git a/lib/Serialization/ASTReaderDecl.cpp b/lib/Serialization/ASTReaderDecl.cpp
index 4871a3049ab9c53c8eb1f2f5e3fb5f1f9b81ffc2..c00b69cf75b0a503f1e16964072ae3ac95af2738 100644 (file)
--- a/lib/Serialization/ASTReaderDecl.cpp
+++ b/lib/Serialization/ASTReaderDecl.cpp
@@ -402,9 +402,14 @@ void ASTDeclReader::VisitTypeDecl(TypeDecl *TD) {
 }
 
 void ASTDeclReader::VisitTypedefNameDecl(TypedefNameDecl *TD) {
-  VisitRedeclarable(TD);
+  // Record the declaration -> global ID mapping.
+  Reader.DeclToID[TD] = ThisDeclID;
+  
+  RedeclarableResult Redecl = VisitRedeclarable(TD);
   VisitTypeDecl(TD);
-  TD->setTypeSourceInfo(GetTypeSourceInfo(Record, Idx));  
+  
+  TD->setTypeSourceInfo(GetTypeSourceInfo(Record, Idx));
+  mergeRedeclarable(TD, Redecl);
 }
 
 void ASTDeclReader::VisitTypedefDecl(TypedefDecl *TD) {
@@ -1668,15 +1673,22 @@ static bool isSameEntity(NamedDecl *X, NamedDecl *Y) {
   if (X == Y)
     return true;
   
-  // Must have the same kind.
-  if (X->getKind() != Y->getKind())
-    return false;
-  
   // Must be in the same context.
   if (!X->getDeclContext()->getRedeclContext()->Equals(
          Y->getDeclContext()->getRedeclContext()))
     return false;
+
+  // Two typedefs refer to the same entity if they have the same underlying
+  // type.
+  if (TypedefNameDecl *TypedefX = dyn_cast<TypedefNameDecl>(X))
+    if (TypedefNameDecl *TypedefY = dyn_cast<TypedefNameDecl>(Y))
+      return X->getASTContext().hasSameType(TypedefX->getUnderlyingType(),
+                                            TypedefY->getUnderlyingType());
   
+  // Must have the same kind.
+  if (X->getKind() != Y->getKind())
+    return false;
+    
   // Objective-C classes and protocols with the same name always match.
   if (isa<ObjCInterfaceDecl>(X) || isa<ObjCProtocolDecl>(X))
     return true;