commit d8eb456289a81728f9aac77ac0a4db0ea9cc231a
author Steve Naroff <snaroff@apple.com> Fri Mar 13 16:03:38 2009 +0000
committer Steve Naroff <snaroff@apple.com> Fri Mar 13 16:03:38 2009 +0000
tree 0e0b9836630a0cb8c3158d878c9060e30d9020d9
parent 1060a3c4aea59d571217bd359067f88b03fe092a

Reimplement fix for <rdar://problem/6451399> problems with labels and blocks.

This solution is much simpler (and doesn't add any per-scope overhead, which concerned Chris). 

The only downside is the LabelMap is now declared in two places (Sema and BlockSemaInfo). My original fix tried to unify the LabelMap in "Scope" (which would support nested functions in general). In any event, this fixes the bug given the current language definition. If/when we decide to support GCC style nested functions, this will need to be tweaked.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@66896 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Sema/Sema.h

diff --git a/lib/Sema/Sema.h b/lib/Sema/Sema.h
index b403a8b..d49efdd 100644
--- a/lib/Sema/Sema.h
+++ b/lib/Sema/Sema.h
@@ -2310,6 +2310,11 @@
   /// return types, if any, in the block body.
   Type *ReturnType;
   
+  /// LabelMap - This is a mapping from label identifiers to the LabelStmt for
+  /// it (which acts like the label decl in some ways).  Forward referenced
+  /// labels have a LabelStmt created for them with a null location & SubStmt.
+  llvm::DenseMap<IdentifierInfo*, LabelStmt*> LabelMap;
+  
   /// PrevBlockInfo - If this is nested inside another block, this points
   /// to the outer block.
   BlockSemaInfo *PrevBlockInfo;

lib/Sema/SemaExpr.cpp

diff --git a/lib/Sema/SemaExpr.cpp b/lib/Sema/SemaExpr.cpp
index 9f915fc..8324d8d 100644
--- a/lib/Sema/SemaExpr.cpp
+++ b/lib/Sema/SemaExpr.cpp
@@ -4336,7 +4336,8 @@
                                       SourceLocation LabLoc,
                                       IdentifierInfo *LabelII) {
   // Look up the record for this label identifier.
-  LabelStmt *&LabelDecl = LabelMap[LabelII];
+  LabelStmt *&LabelDecl = CurBlock ? CurBlock->LabelMap[LabelII] : 
+                                     LabelMap[LabelII];
 
   // If we haven't seen this label yet, create a forward reference. It
   // will be validated and/or cleaned up in ActOnFinishFunctionBody.

lib/Sema/SemaStmt.cpp

diff --git a/lib/Sema/SemaStmt.cpp b/lib/Sema/SemaStmt.cpp
index f8e2255..96e59f0 100644
--- a/lib/Sema/SemaStmt.cpp
+++ b/lib/Sema/SemaStmt.cpp
@@ -170,7 +170,7 @@
                      SourceLocation ColonLoc, StmtArg subStmt) {
   Stmt *SubStmt = static_cast<Stmt*>(subStmt.release());
   // Look up the record for this label identifier.
-  LabelStmt *&LabelDecl = LabelMap[II];
+  LabelStmt *&LabelDecl = CurBlock ? CurBlock->LabelMap[II] : LabelMap[II];
 
   // If not forward referenced or defined already, just create a new LabelStmt.
   if (LabelDecl == 0)
@@ -676,7 +676,8 @@
     return StmtError(Diag(GotoLoc, diag::err_goto_in_block));
 
   // Look up the record for this label identifier.
-  LabelStmt *&LabelDecl = LabelMap[LabelII];
+  LabelStmt *&LabelDecl = CurBlock ? CurBlock->LabelMap[LabelII] : 
+                                     LabelMap[LabelII];
 
   // If we haven't seen this label yet, create a forward reference.
   if (LabelDecl == 0)

test/Sema/block-labels.c

diff --git a/test/Sema/block-labels.c b/test/Sema/block-labels.c
index e69de29..15e6f61 100644
--- a/test/Sema/block-labels.c
+++ b/test/Sema/block-labels.c
@@ -0,0 +1,17 @@
+// RUN: clang %s -verify -fblocks -fsyntax-only
+
+int a() { 
+  A:if (1) xx();
+  return ^{A:return 1;}();
+}
+int b() { 
+  A: return ^{int a; A:return 1;}();
+}
+
+int d() { 
+  A: return ^{int a; A: a = ^{int a; A:return 1;}() + ^{int b; A:return 2;}(); return a; }();
+}
+
+int c() { 
+  goto A; return ^{ A:return 1;}(); // expected-error {{use of undeclared label 'A'}}
+}