commit dd5eb9df0cd248bc20fdca01f007f7119633a7d7
author Fariborz Jahanian <fjahanian@apple.com> Sat Dec 03 17:47:53 2011 +0000
committer Fariborz Jahanian <fjahanian@apple.com> Sat Dec 03 17:47:53 2011 +0000
tree c356b1607c20723349636ca119cae1a3dd635681
parent 71ba18c1e08ea0a323974be32bebffeaa60808da

If block literal return type is not specified, return type of the block is 
inferred from return types. All the return statements have to agree about the type.
// rdar://10466373

llvm-svn: 145774

clang/lib/Sema/SemaExpr.cpp

diff --git a/clang/lib/Sema/SemaExpr.cpp b/clang/lib/Sema/SemaExpr.cpp
index 1e9f319..cc94050 100644
--- a/clang/lib/Sema/SemaExpr.cpp
+++ b/clang/lib/Sema/SemaExpr.cpp
@@ -8715,8 +8715,10 @@
   // return type.  TODO:  what should we do with declarators like:
   //   ^ * { ... }
   // If the answer is "apply template argument deduction"....
-  if (RetTy != Context.DependentTy)
+  if (RetTy != Context.DependentTy) {
     CurBlock->ReturnType = RetTy;
+    CurBlock->TheDecl->setBlockMissingReturnType(false);
+  }
 
   // Push block parameters from the declarator if we had them.
   SmallVector<ParmVarDecl*, 8> Params;

clang/lib/Sema/SemaStmt.cpp

diff --git a/clang/lib/Sema/SemaStmt.cpp b/clang/lib/Sema/SemaStmt.cpp
index e8a6104..1255695 100644
--- a/clang/lib/Sema/SemaStmt.cpp
+++ b/clang/lib/Sema/SemaStmt.cpp
@@ -1809,6 +1809,16 @@
   } else if (!RetValExp) {
     return StmtError(Diag(ReturnLoc, diag::err_block_return_missing_expr));
   } else if (!RetValExp->isTypeDependent()) {
+    if (CurBlock->TheDecl->blockMissingReturnType()) {
+      // when block's return type is not specified, all return types
+      // must strictly match.
+      if (Context.getCanonicalType(FnRetType) != 
+          Context.getCanonicalType(RetValExp->getType())) {
+          Diag(ReturnLoc, diag::err_typecheck_missing_return_type_incompatible) 
+            << RetValExp->getType() << FnRetType;
+          return StmtError();
+      }
+    }
     // we have a non-void block with an expression, continue checking
 
     // C99 6.8.6.4p3(136): The return statement is not an assignment. The
@@ -1820,7 +1830,7 @@
     NRVOCandidate = getCopyElisionCandidate(FnRetType, RetValExp, false);
     InitializedEntity Entity = InitializedEntity::InitializeResult(ReturnLoc,
                                                                    FnRetType,
-                                                           NRVOCandidate != 0);
+                                                          NRVOCandidate != 0);
     ExprResult Res = PerformMoveOrCopyInitialization(Entity, NRVOCandidate,
                                                      FnRetType, RetValExp);
     if (Res.isInvalid()) {

clang/lib/Sema/TreeTransform.h

diff --git a/clang/lib/Sema/TreeTransform.h b/clang/lib/Sema/TreeTransform.h
index d7bdbaf..3dc8136 100644
--- a/clang/lib/Sema/TreeTransform.h
+++ b/clang/lib/Sema/TreeTransform.h
@@ -8118,6 +8118,8 @@
   // in above, CapturesCXXThis need be set here from the block
   // expression.
   blockScope->CapturesCXXThis = oldBlock->capturesCXXThis();
+  blockScope->TheDecl->setBlockMissingReturnType(
+                         oldBlock->blockMissingReturnType());
   
   SmallVector<ParmVarDecl*, 4> params;
   SmallVector<QualType, 4> paramTypes;