Fix some corner cases in skipping native methods using caller.

test/mjsunit/regress/regress-145201.js

+// Copyright 2012 the V8 project authors. All rights reserved.
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+// modification, are permitted provided that the following conditions are
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+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Fix some corner cases in skipping native methods using caller.
+var net = [];
+
+
+var x = 0;
+
+function collect () {
+  function item(operator) {
+    binary(operator, 1, false);
+    binary(operator, 1, true);
+    binary(operator, '{}', false);
+    binary(operator, '{}', true);
+    binary(operator, '"x"', false);
+    binary(operator, '"x"', true);
+    unary(operator, "");
+  }
+
+  function unary(op, after) {
+    // Capture:
+    try {
+      eval(op + " custom " + after);
+    } catch(e) {
+    }
+  }
+
+  function binary(op, other_side, inverted) {
+    // Capture:
+    try {
+      if (inverted) {
+        eval("custom " + op + " " + other_side);
+      } else {
+        eval(other_side + " " + op + " custom");
+      }
+    } catch(e) {
+    }
+  }
+
+  function catcher() {
+    var caller = catcher.caller;
+    if (/native/i.test(caller) || /ADD/.test(caller)) {

[Yang, 2012/09/04 12:43:57]

Why do we only test for /ADD/, not for e.g. /MUL/?

[Erik Corry, 2012/09/05 07:22:33]

If we ever change the stringification of native functions so that the word
'native' does not appear, then this test would stop working (always pass). 
Testing for a specific function that should not appear is a safeguard against
that.

+      net[caller] = 0;
+    }
+  }
+
+  var custom = Object.create(null, {
+    toString: { value: catcher },
+    length: { get: catcher }
+  });
+
+  item('^');
+  item('~');
+  item('<<');
+  item('<');
+  item('==');
+  item('>>>');
+  item('>>');
+  item('|');
+  item('-');
+  item('*');
+  item('&');
+  item('%');
+  item('+');
+  item('in');
+  item('instanceof');
+  unary('{}[', ']');
+  unary('delete {}[', ']');
+  unary('(function() {}).apply(null, ', ')');
+}
+
+collect();
+collect();
+collect();
+
+var keys = 0;
+for (var key in net) {
+  print(key);
+  keys++;
+}
+
+assertTrue(keys == 0);