[strong] Disallow implicit conversions for binary arithmetic operations

src/ic/ic.cc

Index: src/ic/ic.cc
diff --git a/src/ic/ic.cc b/src/ic/ic.cc
index a6ae92a892c06ac9dcc88ecf093a0201e9f0eb12..e2b99bb9f714295738c14b6139120e91abfef24c 100644
--- a/src/ic/ic.cc
+++ b/src/ic/ic.cc
@@ -2568,7 +2568,7 @@ MaybeHandle<Object> BinaryOpIC::Transition(
 
   // Compute the actual result using the builtin for the binary operation.
   Object* builtin = isolate()->js_builtins_object()->javascript_builtin(
-      TokenToJSBuiltin(state.op()));
+      TokenToJSBuiltin(state.op(), state.language_mode()));
   Handle<JSFunction> function = handle(JSFunction::cast(builtin), isolate());
   Handle<Object> result;
   ASSIGN_RETURN_ON_EXCEPTION(
@@ -2805,7 +2805,8 @@ RUNTIME_FUNCTION(Unreachable) {
 }
 
 
-Builtins::JavaScript BinaryOpIC::TokenToJSBuiltin(Token::Value op) {
+Builtins::JavaScript BinaryOpIC::TokenToJSBuiltin(Token::Value op,
+                                                  LanguageMode language_mode) {
   switch (op) {
     default:
       UNREACHABLE();
@@ -2813,16 +2814,16 @@ Builtins::JavaScript BinaryOpIC::TokenToJSBuiltin(Token::Value op) {
       return Builtins::ADD;
       break;
     case Token::SUB:
-      return Builtins::SUB;
+      return is_strong(language_mode) ? Builtins::SUB_STRONG : Builtins::SUB;

[rossberg, 2015/04/23 13:29:37]

Nit: considering that you'll have to add the same to every case eventually, it
seems better to transpose the switch and conditional.

Btw, all the breaks in this switch can be removed.

[conradw, 2015/04/23 14:51:54]

Done.

       break;
     case Token::MUL:
-      return Builtins::MUL;
+      return is_strong(language_mode) ? Builtins::MUL_STRONG : Builtins::MUL;
       break;
     case Token::DIV:
-      return Builtins::DIV;
+      return is_strong(language_mode) ? Builtins::DIV_STRONG : Builtins::DIV;
       break;
     case Token::MOD:
-      return Builtins::MOD;
+      return is_strong(language_mode) ? Builtins::MOD_STRONG : Builtins::MOD;
       break;
     case Token::BIT_OR:
       return Builtins::BIT_OR;