Capture a few implicit references to 'self'.

llvm-svn: 124786

clang/include/clang/Sema/Sema.h

@@ -4269,6 +4269,8 @@ public:
                             SourceLocation receiverNameLoc,
                             SourceLocation propertyNameLoc);
 
+  ObjCMethodDecl *tryCaptureObjCSelf();
+
   /// \brief Describes the kind of message expression indicated by a message
   /// send that starts with an identifier.
   enum ObjCMessageKind {

clang/lib/Sema/SemaExprObjC.cpp

@@ -14,6 +14,7 @@
 #include "clang/Sema/SemaInternal.h"
 #include "clang/Sema/Lookup.h"
 #include "clang/Sema/Scope.h"
+#include "clang/Sema/ScopeInfo.h"
 #include "clang/Sema/Initialization.h"
 #include "clang/AST/ASTContext.h"
 #include "clang/AST/DeclObjC.h"
@@ -23,6 +24,7 @@
 #include "clang/Lex/Preprocessor.h"
 
 using namespace clang;
+using namespace sema;
 
 ExprResult Sema::ParseObjCStringLiteral(SourceLocation *AtLocs,
                                         Expr **strings,
@@ -195,6 +197,37 @@ ExprResult Sema::ParseObjCProtocolExpression(IdentifierInfo *ProtocolId,
   return new (Context) ObjCProtocolExpr(Ty, PDecl, AtLoc, RParenLoc);
 }
 
+/// Try to capture an implicit reference to 'self'.
+ObjCMethodDecl *Sema::tryCaptureObjCSelf() {
+  // Ignore block scopes: we can capture through them.
+  DeclContext *DC = CurContext;
+  while (true) {
+    if (isa<BlockDecl>(DC)) DC = cast<BlockDecl>(DC)->getDeclContext();
+    else if (isa<EnumDecl>(DC)) DC = cast<EnumDecl>(DC)->getDeclContext();
+    else break;
+  }
+
+  // If we're not in an ObjC method, error out.  Note that, unlike the
+  // C++ case, we don't require an instance method --- class methods
+  // still have a 'self', and we really do still need to capture it!
+  ObjCMethodDecl *method = dyn_cast<ObjCMethodDecl>(DC);
+  if (!method)
+    return 0;
+
+  ImplicitParamDecl *self = method->getSelfDecl();
+  assert(self && "capturing 'self' in non-definition?");
+
+  // Mark that we're closing on 'this' in all the block scopes, if applicable.
+  for (unsigned idx = FunctionScopes.size() - 1;
+       isa<BlockScopeInfo>(FunctionScopes[idx]);
+       --idx)
+    if (!cast<BlockScopeInfo>(FunctionScopes[idx])->Captures.insert(self))
+      break;
+
+  return method;
+}
+
+
 bool Sema::CheckMessageArgumentTypes(Expr **Args, unsigned NumArgs,
                                      Selector Sel, ObjCMethodDecl *Method,
                                      bool isClassMessage,
@@ -503,8 +536,8 @@ ActOnClassPropertyRefExpr(IdentifierInfo &receiverName,
   if (IFace == 0) {
     // If the "receiver" is 'super' in a method, handle it as an expression-like
     // property reference.
-    if (ObjCMethodDecl *CurMethod = getCurMethodDecl())
-      if (receiverNamePtr->isStr("super")) {
+    if (receiverNamePtr->isStr("super")) {
+      if (ObjCMethodDecl *CurMethod = tryCaptureObjCSelf()) {
         if (CurMethod->isInstanceMethod()) {
           QualType T = 
             Context.getObjCInterfaceType(CurMethod->getClassInterface());
@@ -520,6 +553,7 @@ ActOnClassPropertyRefExpr(IdentifierInfo &receiverName,
         // superclass.
         IFace = CurMethod->getClassInterface()->getSuperClass();
       }
+    }
     
     if (IFace == 0) {
       Diag(receiverNameLoc, diag::err_expected_ident_or_lparen);
@@ -700,7 +734,7 @@ ExprResult Sema::ActOnSuperMessage(Scope *S,
                                    SourceLocation RBracLoc,
                                    MultiExprArg Args) {
   // Determine whether we are inside a method or not.
-  ObjCMethodDecl *Method = getCurMethodDecl();
+  ObjCMethodDecl *Method = tryCaptureObjCSelf();
   if (!Method) {
     Diag(SuperLoc, diag::err_invalid_receiver_to_message_super);
     return ExprError();