Keep an explicit stack of function and block scopes, each element of

which has the label map, switch statement stack, etc. Previously, we
had a single set of maps in Sema (for the function) along with a stack
of block scopes. However, this lead to funky behavior with nested
functions, e.g., in the member functions of local classes.

The explicit-stack approach is far cleaner, and we retain a 1-element
cache so that we're not malloc/free'ing every time we enter a
function. Fixes PR6382.

Also, tweaked the unused-variable warning suppression logic to look at
errors within a given Scope rather than within a given function. The
prior code wasn't looking at the right number-of-errors count when
dealing with blocks, since the block's count would be deallocated
before we got to ActOnPopScope. This approach works with nested
blocks/functions, and gives tighter error recovery.

llvm-svn: 97518

1 files changed, 3 insertions, 5 deletions

diff --git a/clang/lib/Sema/SemaDeclObjC.cpp b/clang/lib/Sema/SemaDeclObjC.cpp
index 0ec793360b0..149fe15fabe 100644
--- a/clang/lib/Sema/SemaDeclObjC.cpp
+++ b/clang/lib/Sema/SemaDeclObjC.cpp
@@ -49,9 +49,6 @@ void Sema::ActOnStartOfObjCMethodDef(Scope *FnBodyScope, DeclPtrTy D) {
   if (!MDecl)
     return;
 
-  CurFunctionNeedsScopeChecking = false;
-  NumErrorsAtStartOfFunction = getDiagnostics().getNumErrors();
-
   // Allow the rest of sema to find private method decl implementations.
   if (MDecl->isInstanceMethod())
     AddInstanceMethodToGlobalPool(MDecl);
@@ -60,7 +57,8 @@ void Sema::ActOnStartOfObjCMethodDef(Scope *FnBodyScope, DeclPtrTy D) {
 
   // Allow all of Sema to see that we are entering a method definition.
   PushDeclContext(FnBodyScope, MDecl);
-
+  PushFunctionScope();
+  
   // Create Decl objects for each parameter, entrring them in the scope for
   // binding to their use.
 
@@ -1989,7 +1987,7 @@ Sema::DeclPtrTy Sema::ActOnMethodDeclaration(
   // Make sure we can establish a context for the method.
   if (!ClassDecl) {
     Diag(MethodLoc, diag::error_missing_method_context);
-    FunctionLabelMap.clear();
+    getLabelMap().clear();
     return DeclPtrTy();
   }
   QualType resultDeclType;