Handle Objective-C type arguments.

Objective-C type arguments can be provided in angle brackets following
an Objective-C interface type. Syntactically, this is the same
position as one would provide protocol qualifiers (e.g.,
id<NSCopying>), so parse both together and let Sema sort out the
ambiguous cases. This applies both when parsing types and when parsing
the superclass of an Objective-C class, which can now be a specialized
type (e.g., NSMutableArray<T> inherits from NSArray<T>).

Check Objective-C type arguments against the type parameters of the
corresponding class. Verify the length of the type argument list and
that each type argument satisfies the corresponding bound.

Specializations of parameterized Objective-C classes are represented
in the type system as distinct types. Both specialized types (e.g.,
NSArray<NSString *> *) and unspecialized types (NSArray *) are
represented, separately.

llvm-svn: 241542

2 files changed, 44 insertions, 1 deletions

diff --git a/clang/tools/libclang/CIndex.cpp b/clang/tools/libclang/CIndex.cpp
index 6c887e18896..a2467ebad4a 100644
--- a/clang/tools/libclang/CIndex.cpp
+++ b/clang/tools/libclang/CIndex.cpp
@@ -1021,6 +1021,9 @@ bool CursorVisitor::VisitObjCCategoryDecl(ObjCCategoryDecl *ND) {
                                    TU)))
     return true;
 
+  if (VisitObjCTypeParamList(ND->getTypeParamList()))
+    return true;
+
   ObjCCategoryDecl::protocol_loc_iterator PL = ND->protocol_loc_begin();
   for (ObjCCategoryDecl::protocol_iterator I = ND->protocol_begin(),
          E = ND->protocol_end(); I != E; ++I, ++PL)
@@ -1080,12 +1083,37 @@ bool CursorVisitor::VisitObjCPropertyDecl(ObjCPropertyDecl *PD) {
   return false;
 }
 
+bool CursorVisitor::VisitObjCTypeParamList(ObjCTypeParamList *typeParamList) {
+  if (!typeParamList)
+    return false;
+
+  for (auto *typeParam : *typeParamList) {
+    // Visit the type parameter.
+    if (Visit(MakeCXCursor(typeParam, TU, RegionOfInterest)))
+      return true;
+
+    // Visit the bound, if it's explicit.
+    if (typeParam->hasExplicitBound()) {
+      if (auto TInfo = typeParam->getTypeSourceInfo()) {
+        if (Visit(TInfo->getTypeLoc()))
+          return true;
+      }
+    }
+  }
+
+  return false;
+}
+
 bool CursorVisitor::VisitObjCInterfaceDecl(ObjCInterfaceDecl *D) {
   if (!D->isThisDeclarationADefinition()) {
     // Forward declaration is treated like a reference.
     return Visit(MakeCursorObjCClassRef(D, D->getLocation(), TU));
   }
 
+  // Objective-C type parameters.
+  if (VisitObjCTypeParamList(D->getTypeParamListAsWritten()))
+    return true;
+
   // Issue callbacks for super class.
   if (D->getSuperClass() &&
       Visit(MakeCursorObjCSuperClassRef(D->getSuperClass(),
@@ -1093,6 +1121,10 @@ bool CursorVisitor::VisitObjCInterfaceDecl(ObjCInterfaceDecl *D) {
                                         TU)))
     return true;
 
+  if (TypeSourceInfo *SuperClassTInfo = D->getSuperClassTInfo())
+    if (Visit(SuperClassTInfo->getTypeLoc()))
+      return true;
+
   ObjCInterfaceDecl::protocol_loc_iterator PL = D->protocol_loc_begin();
   for (ObjCInterfaceDecl::protocol_iterator I = D->protocol_begin(),
          E = D->protocol_end(); I != E; ++I, ++PL)
@@ -1486,6 +1518,11 @@ bool CursorVisitor::VisitObjCObjectTypeLoc(ObjCObjectTypeLoc TL) {
   if (TL.hasBaseTypeAsWritten() && Visit(TL.getBaseLoc()))
     return true;
 
+  for (unsigned I = 0, N = TL.getNumTypeArgs(); I != N; ++I) {
+    if (Visit(TL.getTypeArgTInfo(I)->getTypeLoc()))
+      return true;
+  }
+
   for (unsigned I = 0, N = TL.getNumProtocols(); I != N; ++I) {
     if (Visit(MakeCursorObjCProtocolRef(TL.getProtocol(I), TL.getProtocolLoc(I),
                                         TU)))
@@ -4411,7 +4448,12 @@ static enum CXChildVisitResult GetCursorVisitor(CXCursor cursor,
     *BestCursor = getTypeRefedCallExprCursor(*BestCursor);
     return CXChildVisit_Recurse;
   }
-  
+
+  // If we already have an Objective-C superclass reference, don't
+  // update it further.
+  if (BestCursor->kind == CXCursor_ObjCSuperClassRef)
+    return CXChildVisit_Break;
+
   *BestCursor = cursor;
   return CXChildVisit_Recurse;
 }
diff --git a/clang/tools/libclang/CursorVisitor.h b/clang/tools/libclang/CursorVisitor.h
index 1b2a922204f..2a0f5205984 100644
--- a/clang/tools/libclang/CursorVisitor.h
+++ b/clang/tools/libclang/CursorVisitor.h
@@ -222,6 +222,7 @@ public:
   bool VisitObjCCategoryDecl(ObjCCategoryDecl *ND);
   bool VisitObjCProtocolDecl(ObjCProtocolDecl *PID);
   bool VisitObjCPropertyDecl(ObjCPropertyDecl *PD);
+  bool VisitObjCTypeParamList(ObjCTypeParamList *typeParamList);
   bool VisitObjCInterfaceDecl(ObjCInterfaceDecl *D);
   bool VisitObjCImplDecl(ObjCImplDecl *D);
   bool VisitObjCCategoryImplDecl(ObjCCategoryImplDecl *D);