[cfe-commits] r134097 - in /cfe/trunk: lib/Sema/SemaDecl.cpp test/Sema/extern-redecl.c

[Douglas Gregor]

Author: dgregor
Date: Wed Jun 29 16:22:02 2011
New Revision: 134097

URL: http://llvm.org/viewvc/llvm-project?rev=134097&view=rev
Log:
When redeclaring a local extern in the same scope, make sure that we
replace the existing declaration appropriately. Patch by Jordy Rose,
fixes PR10013 / <rdar://problem/9584157>.

Modified:
    cfe/trunk/lib/Sema/SemaDecl.cpp
    cfe/trunk/test/Sema/extern-redecl.c

Modified: cfe/trunk/lib/Sema/SemaDecl.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaDecl.cpp?rev=134097&r1=134096&r2=134097&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/SemaDecl.cpp (original)
+++ cfe/trunk/lib/Sema/SemaDecl.cpp Wed Jun 29 16:22:02 2011
@@ -3299,8 +3299,18 @@
   if (S && IdResolver.ReplaceDecl(PrevDecl, ND)) {
     // The previous declaration was found on the identifer resolver
     // chain, so remove it from its scope.
-    while (S && !S->isDeclScope(PrevDecl))
-      S = S->getParent();
+
+    if (S->isDeclScope(PrevDecl)) {
+      // Special case for redeclarations in the SAME scope.
+      // Because this declaration is going to be added to the identifier chain
+      // later, we should temporarily take it OFF the chain.
+      IdResolver.RemoveDecl(ND);
+
+    } else {
+      // Find the scope for the original declaration.
+      while (S && !S->isDeclScope(PrevDecl))
+        S = S->getParent();
+    }
 
     if (S)
       S->RemoveDecl(PrevDecl);

Modified: cfe/trunk/test/Sema/extern-redecl.c
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Sema/extern-redecl.c?rev=134097&r1=134096&r2=134097&view=diff
==============================================================================
--- cfe/trunk/test/Sema/extern-redecl.c (original)
+++ cfe/trunk/test/Sema/extern-redecl.c Wed Jun 29 16:22:02 2011
@@ -1,4 +1,4 @@
-// RUN: %clang_cc1 -fsyntax-only %s
+// RUN: %clang_cc1 -fsyntax-only -verify %s
 
 // rdar: // 8125274
 static int a16[];  // expected-warning {{tentative array definition assumed to have one element}}
@@ -7,3 +7,16 @@
     extern int a16[];
 }
 
+
+// PR10013: Scope of extern declarations extend past enclosing block
+extern int PR10013_x;
+int PR10013(void) {
+  int *PR10013_x = 0;
+  {
+    extern int PR10013_x;
+    extern int PR10013_x; 
+  }
+  
+  return PR10013_x; // expected-warning{{incompatible pointer to integer conversion}}
+}
+