objc-arc: bridge casts in non-objc-arc mode are ignord.

But, warn too. // rdar://10597832


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@146904 91177308-0d34-0410-b5e6-96231b3b80d8

3 files changed, 19 insertions, 14 deletions

diff --git a/lib/Basic/IdentifierTable.cpp b/lib/Basic/IdentifierTable.cpp
index 94ca1789f3..f5b417c72c 100644
--- a/lib/Basic/IdentifierTable.cpp
+++ b/lib/Basic/IdentifierTable.cpp
@@ -125,7 +125,9 @@ static void AddKeyword(StringRef Keyword,
   else if (LangOpts.OpenCL && (Flags & KEYOPENCL)) AddResult = 2;
   else if (!LangOpts.CPlusPlus && (Flags & KEYNOCXX)) AddResult = 2;
   else if (LangOpts.C1X && (Flags & KEYC1X)) AddResult = 2;
-  else if (LangOpts.ObjCAutoRefCount && (Flags & KEYARC)) AddResult = 2;
+  // We treat bridge casts as objective-C keywords so we can warn on them
+  // in non-arc mode.
+  else if (LangOpts.ObjC2 && (Flags & KEYARC)) AddResult = 2;
   else if (LangOpts.CPlusPlus && (Flags & KEYCXX0X)) AddResult = 3;
 
   // Don't add this keyword if disabled in this language.
diff --git a/lib/Basic/Targets.cpp b/lib/Basic/Targets.cpp
index 07e61d80ba..34ae1d3b16 100644
--- a/lib/Basic/Targets.cpp
+++ b/lib/Basic/Targets.cpp
@@ -99,13 +99,6 @@ static void getDarwinDefines(MacroBuilder &Builder, const LangOptions &Opts,
     // allow this in C, since one might have block pointers in structs that
     // are used in pure C code and in Objective-C ARC.
     Builder.defineMacro("__unsafe_unretained", "");
-
-    // The Objective-C bridged cast keywords are defined to nothing in non-ARC
-    // mode; then they become normal, C-style casts.
-    Builder.defineMacro("__bridge", "");
-    Builder.defineMacro("__bridge_transfer", "");
-    Builder.defineMacro("__bridge_retained", "");
-    Builder.defineMacro("__bridge_retain", "");
   }
 
   if (Opts.Static)
diff --git a/lib/Parse/ParseExpr.cpp b/lib/Parse/ParseExpr.cpp
index dcbee4f9e6..bb446f5ab2 100644
--- a/lib/Parse/ParseExpr.cpp
+++ b/lib/Parse/ParseExpr.cpp
@@ -1817,9 +1817,23 @@ Parser::ParseParenExpression(ParenParseOption &ExprType, bool stopIfCastExpr,
     return ExprError();
   }
 
+  // Diagnose use of bridge casts in non-arc mode.
+  bool BridgeCast = (getLang().ObjC2 &&
+                     (Tok.is(tok::kw___bridge) || 
+                      Tok.is(tok::kw___bridge_transfer) ||
+                      Tok.is(tok::kw___bridge_retained) ||
+                      Tok.is(tok::kw___bridge_retain)));
+  if (BridgeCast && !getLang().ObjCAutoRefCount) {
+    SourceLocation BridgeKeywordLoc = ConsumeToken();
+    if (!PP.getSourceManager().isInSystemHeader(BridgeKeywordLoc))
+      Diag(BridgeKeywordLoc, diag::warn_arc_bridge_retain)
+      << FixItHint::CreateReplacement(BridgeKeywordLoc,
+                                      "");
+    BridgeCast = false;
+  }
+  
   // None of these cases should fall through with an invalid Result
   // unless they've already reported an error.
-  
   if (ExprType >= CompoundStmt && Tok.is(tok::l_brace)) {
     Diag(Tok, diag::ext_gnu_statement_expr);
     ParsedAttributes attrs(AttrFactory);
@@ -1829,11 +1843,7 @@ Parser::ParseParenExpression(ParenParseOption &ExprType, bool stopIfCastExpr,
     // If the substmt parsed correctly, build the AST node.
     if (!Stmt.isInvalid())
       Result = Actions.ActOnStmtExpr(OpenLoc, Stmt.take(), Tok.getLocation());
-  } else if (ExprType >= CompoundLiteral && 
-             (Tok.is(tok::kw___bridge) || 
-              Tok.is(tok::kw___bridge_transfer) ||
-              Tok.is(tok::kw___bridge_retained) ||
-              Tok.is(tok::kw___bridge_retain))) {
+  } else if (ExprType >= CompoundLiteral && BridgeCast) {
     tok::TokenKind tokenKind = Tok.getKind();
     SourceLocation BridgeKeywordLoc = ConsumeToken();