commit 9d0840141a0922e2d8b1d322f21ef51803ede23d
author Ted Kremenek <kremenek@apple.com> Fri Dec 21 08:04:28 2012 +0000
committer Ted Kremenek <kremenek@apple.com> Fri Dec 21 08:04:28 2012 +0000
tree 4d653e340bbfdfb1cb007f45a531ec5880933b3e
parent b1ea510de0ef4ebfbbe8fa7668ab1635410fc080

Extend checkUnsafeAssigns() to also handle assigning an object literal to a weak reference.

Thanks to Jordan Rose and John McCall for their sage code review.

Fixes <rdar://problem/12569201>.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@170864 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Sema/SemaChecking.cpp

diff --git a/lib/Sema/SemaChecking.cpp b/lib/Sema/SemaChecking.cpp
index eafe595..f58396f 100644
--- a/lib/Sema/SemaChecking.cpp
+++ b/lib/Sema/SemaChecking.cpp
@@ -5766,6 +5766,39 @@
   return false;
 }
 
+static bool checkUnsafeAssignLiteral(Sema &S, SourceLocation Loc,
+                                     Expr *RHS, bool isProperty) {
+  // Check if RHS is an Objective-C object literal, which also can get
+  // immediately zapped in a weak reference.  Note that we explicitly
+  // allow ObjCStringLiterals, since those are designed to never really die.
+  RHS = RHS->IgnoreParenImpCasts();
+  unsigned kind = 4;
+  switch (RHS->getStmtClass()) {
+    default:
+      break;
+    case Stmt::ObjCDictionaryLiteralClass:
+      kind = 0;
+      break;
+    case Stmt::ObjCArrayLiteralClass:
+      kind = 1;
+      break;
+    case Stmt::BlockExprClass:
+      kind = 2;
+      break;
+    case Stmt::ObjCBoxedExprClass:
+      kind = 3;
+      break;
+  }
+  if (kind < 4) {
+    S.Diag(Loc, diag::warn_arc_literal_assign)
+    << kind
+    << (isProperty ? 0 : 1)
+    << RHS->getSourceRange();
+    return true;
+  }
+  return false;
+}
+
 bool Sema::checkUnsafeAssigns(SourceLocation Loc,
                               QualType LHS, Expr *RHS) {
   Qualifiers::ObjCLifetime LT = LHS.getObjCLifetime();
@@ -5776,6 +5809,10 @@
   if (checkUnsafeAssignObject(*this, Loc, LT, RHS, false))
     return true;
 
+  if (LT == Qualifiers::OCL_Weak &&
+      checkUnsafeAssignLiteral(*this, Loc, RHS, false))
+    return true;
+
   return false;
 }
 
@@ -5840,6 +5877,8 @@
     else if (Attributes & ObjCPropertyDecl::OBJC_PR_weak) {
       if (checkUnsafeAssignObject(*this, Loc, Qualifiers::OCL_Weak, RHS, true))
         return;
+      if (checkUnsafeAssignLiteral(*this, Loc, RHS, true))
+        return;
     }
   }
 }