Fix arguments object materialization during deopt.

test/mjsunit/regress/regress-2261.js

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+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Flags: --allow-natives-syntax
+
+// Test materialization of the arguments object when deoptimizing a
+// strict mode closure after modifying an argument.
+

[Sven Panne, 2012/09/12 07:14:22]

As was dicussed already offline, it would be good to have test cases which
involve an arguments adaptor (both with too few/to many arguments), even if it
is not easily possible to do without extensive copy-n-paste. I would very much
prefer a broader test coverage for such a tricky area over copy-n-paste-free
code. :-)

Probably these tests should live in mjsunit/compiler then.

[Michael Starzinger, 2012/09/12 12:04:25]

Done. Added a generic test case to mjsunit/compiler/inline-arguments that tests
all combinations of arguments adapters for two-level inlining.

+(function () {
+  var forceDeopt = 0;
+  function inner(x) {
+    "use strict";
+    x = 2;
+    // Do not remove this %DebugPrint as it makes sure the deopt happens
+    // after the assignment and is not hoisted above the assignment.
+    %DebugPrint(arguments[0]);
+    forceDeopt + 1;
+    return arguments[0];
+  }
+
+  assertEquals(1, inner(1));
+  assertEquals(1, inner(1));
+  %OptimizeFunctionOnNextCall(inner);
+  assertEquals(1, inner(1));
+  forceDeopt = "not a number";
+  assertEquals(1, inner(1));
+})();
+
+
+// Test materialization of the arguments object when deoptimizing an
+// inlined strict mode closure after modifying an argument.
+
+(function () {
+  var forceDeopt = 0;
+  function inner(x) {
+    "use strict";
+    x = 2;
+    // Do not remove this %DebugPrint as it makes sure the deopt happens
+    // after the assignment and is not hoisted above the assignment.
+    %DebugPrint(arguments[0]);
+    forceDeopt + 1;
+    return arguments[0];
+  }
+
+  function outer(x) {
+    return inner(x);
+  }
+
+  assertEquals(1, outer(1));
+  assertEquals(1, outer(1));
+  %OptimizeFunctionOnNextCall(outer);
+  assertEquals(1, outer(1));
+  forceDeopt = "not a number";
+  assertEquals(1, outer(1));
+})();
+
+
+// Test materialization of the multiple arguments objects when
+// deoptimizing several inlined closure after modifying an argument.
+
+(function () {
+  var forceDeopt = 0;
+  function inner(x,y,z) {
+    "use strict";
+    x = 3;
+    // Do not remove this %DebugPrint as it makes sure the deopt happens
+    // after the assignment and is not hoisted above the assignment.
+    %DebugPrint(arguments[0]);
+    forceDeopt + 1;
+    return arguments[0];
+  }
+
+  function middle(x) {
+    "use strict";
+    x = 2;
+    return inner(10*x, 20*x, 30*x) + arguments[0];
+  }
+
+  function outer(x) {
+   return middle(x);
+  }
+
+  assertEquals(21, outer(1));
+  assertEquals(21, outer(1));
+  %OptimizeFunctionOnNextCall(outer);
+  assertEquals(21, outer(1));
+  forceDeopt = "not a number";
+  assertEquals(21, outer(1));
+})();