r179053 - <rdar://problem/13540921> Fix a crasher when an Objective-C for-in loop gets a non-variable iteration declaration.

[Douglas Gregor]

Author: dgregor
Date: Mon Apr  8 15:52:24 2013
New Revision: 179053

URL: http://llvm.org/viewvc/llvm-project?rev=179053&view=rev
Log:
<rdar://problem/13540921> Fix a crasher when an Objective-C for-in loop gets a non-variable iteration declaration.

Modified:
    cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td
    cfe/trunk/lib/Parse/ParseDecl.cpp
    cfe/trunk/lib/Sema/SemaStmt.cpp
    cfe/trunk/test/SemaObjCXX/foreach.mm

Modified: cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td?rev=179053&r1=179052&r2=179053&view=diff
==============================================================================
--- cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td (original)
+++ cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td Mon Apr  8 15:52:24 2013
@@ -6029,8 +6029,10 @@ def ext_mixed_decls_code : Extension<
   "ISO C90 forbids mixing declarations and code">,
   InGroup<DiagGroup<"declaration-after-statement">>;
   
-def err_non_variable_decl_in_for : Error<
+def err_non_local_variable_decl_in_for : Error<
   "declaration of non-local variable in 'for' loop">;
+def err_non_variable_decl_in_for : Error<
+  "non-variable declaration in 'for' loop">;
 def err_toomany_element_decls : Error<
   "only one element declaration is allowed">;
 def err_selector_element_not_lvalue : Error<

Modified: cfe/trunk/lib/Parse/ParseDecl.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Parse/ParseDecl.cpp?rev=179053&r1=179052&r2=179053&view=diff
==============================================================================
--- cfe/trunk/lib/Parse/ParseDecl.cpp (original)
+++ cfe/trunk/lib/Parse/ParseDecl.cpp Mon Apr  8 15:52:24 2013
@@ -1527,14 +1527,23 @@ Parser::DeclGroupPtrTy Parser::ParseDecl
   // C++0x [stmt.iter]p1: Check if we have a for-range-declarator. If so, we
   // must parse and analyze the for-range-initializer before the declaration is
   // analyzed.
-  if (FRI && Tok.is(tok::colon)) {
-    FRI->ColonLoc = ConsumeToken();
-    if (Tok.is(tok::l_brace))
-      FRI->RangeExpr = ParseBraceInitializer();
-    else
-      FRI->RangeExpr = ParseExpression();
+  //
+  // Handle the Objective-C for-in loop variable similarly, although we
+  // don't need to parse the container in advance.
+  if (FRI && (Tok.is(tok::colon) || isTokIdentifier_in())) {
+    bool IsForRangeLoop = false;
+    if (Tok.is(tok::colon)) {
+      IsForRangeLoop = true;
+      FRI->ColonLoc = ConsumeToken();
+      if (Tok.is(tok::l_brace))
+        FRI->RangeExpr = ParseBraceInitializer();
+      else
+        FRI->RangeExpr = ParseExpression();
+    }
+
     Decl *ThisDecl = Actions.ActOnDeclarator(getCurScope(), D);
-    Actions.ActOnCXXForRangeDecl(ThisDecl);
+    if (IsForRangeLoop)
+      Actions.ActOnCXXForRangeDecl(ThisDecl);
     Actions.FinalizeDeclaration(ThisDecl);
     D.complete(ThisDecl);
     return Actions.FinalizeDeclaratorGroup(getCurScope(), DS, &ThisDecl, 1);

Modified: cfe/trunk/lib/Sema/SemaStmt.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaStmt.cpp?rev=179053&r1=179052&r2=179053&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/SemaStmt.cpp (original)
+++ cfe/trunk/lib/Sema/SemaStmt.cpp Mon Apr  8 15:52:24 2013
@@ -76,10 +76,23 @@ StmtResult Sema::ActOnDeclStmt(DeclGroup
 
 void Sema::ActOnForEachDeclStmt(DeclGroupPtrTy dg) {
   DeclGroupRef DG = dg.getAsVal<DeclGroupRef>();
+  
+  // If we don't have a declaration, or we have an invalid declaration,
+  // just return.
+  if (DG.isNull() || !DG.isSingleDecl())
+    return;
+
+  Decl *decl = DG.getSingleDecl();
+  if (!decl || decl->isInvalidDecl())
+    return;
 
-  // If we have an invalid decl, just return.
-  if (DG.isNull() || !DG.isSingleDecl()) return;
-  VarDecl *var = cast<VarDecl>(DG.getSingleDecl());
+  // Only variable declarations are permitted.
+  VarDecl *var = dyn_cast<VarDecl>(decl);
+  if (!var) {
+    Diag(decl->getLocation(), diag::err_non_variable_decl_in_for);
+    decl->setInvalidDecl();
+    return;
+  }
 
   // suppress any potential 'unused variable' warning.
   var->setUsed();
@@ -1426,9 +1439,10 @@ Sema::ActOnForStmt(SourceLocation ForLoc
         VarDecl *VD = dyn_cast<VarDecl>(*DI);
         if (VD && VD->isLocalVarDecl() && !VD->hasLocalStorage())
           VD = 0;
-        if (VD == 0)
-          Diag((*DI)->getLocation(), diag::err_non_variable_decl_in_for);
-        // FIXME: mark decl erroneous!
+        if (VD == 0) {
+          Diag((*DI)->getLocation(), diag::err_non_local_variable_decl_in_for);
+          (*DI)->setInvalidDecl();
+        }
       }
     }
   }
@@ -1562,14 +1576,17 @@ Sema::ActOnObjCForCollectionStmt(SourceL
         return StmtError(Diag((*DS->decl_begin())->getLocation(),
                          diag::err_toomany_element_decls));
 
-      VarDecl *D = cast<VarDecl>(DS->getSingleDecl());
+      VarDecl *D = dyn_cast<VarDecl>(DS->getSingleDecl());
+      if (!D || D->isInvalidDecl())
+        return StmtError();
+      
       FirstType = D->getType();
       // C99 6.8.5p3: The declaration part of a 'for' statement shall only
       // declare identifiers for objects having storage class 'auto' or
       // 'register'.
       if (!D->hasLocalStorage())
         return StmtError(Diag(D->getLocation(),
-                              diag::err_non_variable_decl_in_for));
+                              diag::err_non_local_variable_decl_in_for));
 
       // If the type contained 'auto', deduce the 'auto' to 'id'.
       if (FirstType->getContainedAutoType()) {

Modified: cfe/trunk/test/SemaObjCXX/foreach.mm
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaObjCXX/foreach.mm?rev=179053&r1=179052&r2=179053&view=diff
==============================================================================
--- cfe/trunk/test/SemaObjCXX/foreach.mm (original)
+++ cfe/trunk/test/SemaObjCXX/foreach.mm Mon Apr  8 15:52:24 2013
@@ -69,3 +69,9 @@ void test2(NSObject<NSFastEnumeration> *
                                 // expected-warning {{property access result unused - getters should not be used for side effects}}
   }
 }
+
+void testErrors(NSArray *array) {
+  typedef int fn(int);
+
+  for (fn x in array) { } // expected-error{{non-variable declaration in 'for' loop}}
+}