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, 8 insertions, 1 deletions

diff --git a/clang/test/Sema/warn-unused-variables.c b/clang/test/Sema/warn-unused-variables.c
index 4d1cde7067e..58e52b171da 100644
--- a/clang/test/Sema/warn-unused-variables.c
+++ b/clang/test/Sema/warn-unused-variables.c
@@ -1,4 +1,4 @@
-// RUN: %clang_cc1 -fsyntax-only -Wunused-variable -verify %s
+// RUN: %clang_cc1 -fsyntax-only -Wunused-variable -fblocks -verify %s
 
 struct s0 {
 	unsigned int	i;
@@ -23,3 +23,10 @@ int f2() {
   int X = 4;  // Shouldn't have a bogus 'unused variable X' warning.
   return Y + X; // expected-error {{use of undeclared identifier 'Y'}}
 }
+
+int f3() {
+  int X1 = 4; 
+  (void)(Y1 + X1); // expected-error {{use of undeclared identifier 'Y1'}}
+  (void)(^() { int X = 4; }); // expected-warning{{unused}}
+  (void)(^() { int X = 4; return Y + X; }); // expected-error {{use of undeclared identifier 'Y'}}
+}