Hydrogen support for stack local harmony bindings in function scope.

test/mjsunit/harmony/block-let-crankshaft.js

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 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
-// Flags: --harmony-scoping --allow-natives-syntax
+// Flags: --harmony-scoping --allow-natives-syntax --trace-bailout

[Jakob Kummerow, 2011/12/05 16:40:36]

I think you should remove --trace-bailout before landing this.

 
 // TODO(ES6): properly activate extended mode
 "use strict";
 
+// Check that the following functions are optimizable.
+var functions = [f1,f2,f3,f4,f5,f6,f7,f8,f9,f10,f11,f12];
+
+for (var i = 0; i < functions.length; ++i) {
+  var func = functions[i];
+  print("Testing:");
+  print(func);
+  for (var j = 0; j < 10; ++j) {
+    func(12);
+  }
+  %OptimizeFunctionOnNextCall(func);
+  func(12);
+  assertTrue(%GetOptimizationStatus(func) != 2);
+}
+
+function f1() { }
+
+function f2(x) { }
+
+function f3() {
+  let x;
+}
+
+function f4() {
+  function foo() {
+  }
+}
+
+function f5() {
+  let x = 1;
+}
+
+function f6() {
+  const x = 1;
+}
+
+function f7(x) {
+  return x;
+}
+
+function f8() {
+  let x;
+  return x;
+}
+
+function f9() {
+  function x() {
+  }
+  return x;
+}
+
+function f10(x) {
+  x = 1;
+}
+
+function f11() {
+  let x;
+  x = 1;
+}
+
+function f12() {
+  function x() {};
+  x = 1;
+}
+
+
 // Test that temporal dead zone semantics for function and block scoped
-// ket bindings are handled by the optimizing compiler.
+// let bindings are handled by the optimizing compiler.
+
+function TestFunctionLocal(s) {
+  'use strict';
+  var func = eval("(function baz(){" + s + "; })");
+  print("Testing:");
+  print(func);
+  for (var i = 0; i < 5; ++i) {
+    try {
+      func();
+      assertUnreachable();
+    } catch (e) {
+      assertInstanceof(e, ReferenceError);
+    }
+  }
+  %OptimizeFunctionOnNextCall(func);
+  try {
+    func();
+    assertUnreachable();
+  } catch (e) {
+    assertInstanceof(e, ReferenceError);
+  }
+}
+
+function TestAll(s) {
+  TestFunctionLocal(s);
+}
+
+// Use before initialization in declaration statement.
+TestAll('let x = x + 1');
+TestAll('let x = x += 1');
+TestAll('let x = x++');
+TestAll('let x = ++x');
+TestAll('const x = x + 1');
+
+// Use before initialization in prior statement.
+TestAll('x + 1; let x;');
+TestAll('x = 1; let x;');
+TestAll('x += 1; let x;');
+TestAll('++x; let x;');
+TestAll('x++; let x;');
+TestAll('let y = x; const x = 1;');
+
 
 function f(x, b) {
   let y = (b ? y : x) + 42;
   return y;
 }
 
 function g(x, b) {
   {
     let y = (b ? y : x) + 42;
     return y;
@@ skipping 12 matching lines @@
   f(42, true);
 } catch (e) {
   assertInstanceof(e, ReferenceError);
 }
 
 try {
   g(42, true);
 } catch (e) {
   assertInstanceof(e, ReferenceError);
 }