patch to optionally warn for block implementations without explicit

return types that return non-void values. // rdar://10735698

llvm-svn: 152047

4 files changed, 31 insertions, 4 deletions

diff --git a/clang/include/clang/Basic/DiagnosticSemaKinds.td b/clang/include/clang/Basic/DiagnosticSemaKinds.td
index 5d3ff2a4af8..816956051c2 100644
--- a/clang/include/clang/Basic/DiagnosticSemaKinds.td
+++ b/clang/include/clang/Basic/DiagnosticSemaKinds.td
@@ -4953,6 +4953,10 @@ def err_blocks_disable : Error<"blocks support disabled - compile with -fblocks"
   " or pick a deployment target that supports them">;
 def err_block_returning_array_function : Error<
   "block cannot return %select{array|function}0 type %1">;
+def warn_block_missing_return_type : Warning<
+  "block literal is missing explicit return type and "
+  "returns non-void values">, 
+  InGroup<DiagGroup<"block-missing-explicit-return-type">>, DefaultIgnore;
 
 // Builtin annotation string.
 def err_builtin_annotation_not_string_constant : Error<
diff --git a/clang/lib/Sema/SemaExpr.cpp b/clang/lib/Sema/SemaExpr.cpp
index ab96f7416fe..aba38db0352 100644
--- a/clang/lib/Sema/SemaExpr.cpp
+++ b/clang/lib/Sema/SemaExpr.cpp
@@ -8902,7 +8902,12 @@ ExprResult Sema::ActOnBlockStmtExpr(SourceLocation CaretLoc,
     ExprCleanupObjects.push_back(Result->getBlockDecl());
     ExprNeedsCleanups = true;
   }
-
+  
+  if (BSI->TheDecl->blockMissingReturnType() &&
+      !RetTy->isDependentType() &&
+      !Context.getCanonicalType(RetTy)->isVoidType())
+    Diag(CaretLoc, diag::warn_block_missing_return_type);
+  
   return Owned(Result);
 }
 
diff --git a/clang/test/Sema/block-missing-return-type-warning.c b/clang/test/Sema/block-missing-return-type-warning.c
new file mode 100644
index 00000000000..c029ae610f3
--- /dev/null
+++ b/clang/test/Sema/block-missing-return-type-warning.c
@@ -0,0 +1,18 @@
+// RUN: %clang_cc1 %s -fsyntax-only -verify -fblocks -Wblock-missing-explicit-return-type
+// rdar://10735698
+
+int f;
+int main() {
+  int (^bar)() = ^{  if (f) return 'a'; // expected-warning {{block literal is missing explicit return type and returns non-void values}}
+                      else return 10; 
+                   };
+
+  void (^bar1)() = ^{ f = 100; };
+
+  void (^bar2)() = ^(void){ f = 100; };
+
+  int (^bar3)() = ^ int {  if (f) return 'a';
+                    	   else return 10;
+                        };
+
+}
diff --git a/clang/test/Sema/warn-unused-parameters.c b/clang/test/Sema/warn-unused-parameters.c
index af048e77e88..28a6bcb799c 100644
--- a/clang/test/Sema/warn-unused-parameters.c
+++ b/clang/test/Sema/warn-unused-parameters.c
@@ -24,7 +24,7 @@ static void achor() {};
 // RUN: %clang_cc1 -fblocks -fsyntax-only -Weverything %s 2>&1 | FileCheck -check-prefix=CHECK-everything %s
 // RUN: %clang_cc1 -fblocks -fsyntax-only -Weverything -Werror %s 2>&1 | FileCheck -check-prefix=CHECK-everything-error %s
 // RUN: %clang_cc1 -fblocks -fsyntax-only -Weverything -Wno-unused %s 2>&1 | FileCheck -check-prefix=CHECK-everything-no-unused %s
-// CHECK-everything: 6 warnings generated
-// CHECK-everything-error: 5 errors generated
-// CHECK-everything-no-unused: 5 warnings generated
+// CHECK-everything: 7 warnings generated
+// CHECK-everything-error: 6 errors generated
+// CHECK-everything-no-unused: 6 warnings generated