[turbofan] Fixing ES6 tail calls in Turbofan.

test/mjsunit/es6/tail-call-megatest.js

+// Copyright 2016 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Flags: --allow-natives-syntax --harmony-tailcalls --no-turbo-inlining
+
+"use strict";
+
+Error.prepareStackTrace = (error,stack) => {
+  error.strace = stack;
+  return error.message + "\n    at " + stack.join("\n    at ");
+}
+
+
+function CheckStackTrace(expected) {
+  var e = new Error();
+  e.stack;  // prepare stack trace
+  var stack = e.strace;
+  assertEquals("CheckStackTrace", stack[0].getFunctionName());
+  for (var i = 0; i < expected.length; i++) {
+    assertEquals(expected[i].name, stack[i + 1].getFunctionName());
+  }
+  // Don't inline. Don't inline. Don't inline. Don't inline.
+  // Don't inline. Don't inline. Don't inline. Don't inline.
+  // Don't inline. Don't inline. Don't inline. Don't inline.
+  // Don't inline. Don't inline. Don't inline. Don't inline.
+  // Don't inline. Don't inline. Don't inline. Don't inline.
+  // Don't inline. Don't inline. Don't inline. Don't inline.
+  // Don't inline. Don't inline. Don't inline. Don't inline.
+  // Don't inline. Don't inline. Don't inline. Don't inline.
+  // Don't inline. Don't inline. Don't inline. Don't inline.
+  // Don't inline. Don't inline. Don't inline. Don't inline.
+  // Don't inline. Don't inline. Don't inline. Don't inline.
+  // Don't inline. Don't inline. Don't inline. Don't inline.
+  // Don't inline. Don't inline. Don't inline. Don't inline.
+  // Don't inline. Don't inline. Don't inline. Don't inline.
+  // Don't inline. Don't inline. Don't inline. Don't inline.
+  // Don't inline. Don't inline. Don't inline. Don't inline.

[Jarin, 2016/02/18 09:08:08]

Could not you use %NeverOptimizeFunction to prevent inlining?

[Igor Sheludko, 2016/02/18 09:30:11]

Good point. For utility functions it makes sense, but not for f() and g()
because I still want them to be optimized (to test TF).

+}
+
+function CheckArguments(expected, args) {
+  args = Array.prototype.slice.call(args);
+  assertEquals(expected, args);
+  // Don't inline. Don't inline. Don't inline. Don't inline.
+  // Don't inline. Don't inline. Don't inline. Don't inline.
+  // Don't inline. Don't inline. Don't inline. Don't inline.
+  // Don't inline. Don't inline. Don't inline. Don't inline.
+  // Don't inline. Don't inline. Don't inline. Don't inline.
+  // Don't inline. Don't inline. Don't inline. Don't inline.
+  // Don't inline. Don't inline. Don't inline. Don't inline.
+  // Don't inline. Don't inline. Don't inline. Don't inline.
+  // Don't inline. Don't inline. Don't inline. Don't inline.
+  // Don't inline. Don't inline. Don't inline. Don't inline.
+  // Don't inline. Don't inline. Don't inline. Don't inline.
+  // Don't inline. Don't inline. Don't inline. Don't inline.
+  // Don't inline. Don't inline. Don't inline. Don't inline.
+  // Don't inline. Don't inline. Don't inline. Don't inline.
+  // Don't inline. Don't inline. Don't inline. Don't inline.
+  // Don't inline. Don't inline. Don't inline. Don't inline.
+}
+
+
+var CAN_INLINE_COMMENT  = "// Let it be inlined.";
+var DONT_INLINE_COMMENT = (function() {
+  var line = "// Don't inline. Don't inline. Don't inline. Don't inline.";
+  for (var i = 0; i < 4; i++) {
+    line += "\n  " + line;
+  }
+  return line;
+})();
+
+
+function ident_source(source, ident) {
+  ident = " ".repeat(ident);
+  return ident + source.replace(/\n/gi, "\n" + ident);
+}
+
+
+function run_tests() {
+
+  function f_template_normal(f_inlinable, f_args) {
+    var f_comment = f_inlinable ? CAN_INLINE_COMMENT : DONT_INLINE_COMMENT;
+    var lines = [
+      `function f(a) {`,
+      `  ${f_comment}`,
+      `  assertEquals(undefined, this);`,
+      `  CheckArguments([${f_args}], arguments);`,
+      `  CheckStackTrace([f, test]);`,
+      `  %DeoptimizeNow();`,
+      `  CheckArguments([${f_args}], arguments);`,
+      `  CheckStackTrace([f, test]);`,
+      `  return 42;`,
+      `}`,
+    ];
+    return lines.join("\n");
+  }
+
+  function f_template_bound(f_inlinable, f_args) {
+    var f_comment = f_inlinable ? CAN_INLINE_COMMENT : DONT_INLINE_COMMENT;
+    var lines = [
+      `function ff(a) {`,
+      `  ${f_comment}`,
+      `  assertEquals(153, this.a);`,
+      `  CheckArguments([${f_args}], arguments);`,
+      `  CheckStackTrace([ff, test]);`,
+      `  %DeoptimizeNow();`,
+      `  CheckArguments([${f_args}], arguments);`,
+      `  CheckStackTrace([ff, test]);`,
+      `  return 42;`,
+      `}`,
+      `var f = ff.bind({a: 153});`,
+    ];
+    return lines.join("\n");
+  }
+
+  function f_template_proxy(f_inlinable, f_args) {
+    var f_comment = f_inlinable ? CAN_INLINE_COMMENT : DONT_INLINE_COMMENT;
+    var lines = [
+      `function ff(a) {`,
+      `  ${f_comment}`,
+      `  assertEquals(undefined, this);`,
+      `  CheckArguments([${f_args}], arguments);`,
+      `  CheckStackTrace([f, test]);`,
+      `  %DeoptimizeNow();`,
+      `  CheckArguments([${f_args}], arguments);`,
+      `  CheckStackTrace([f, test]);`,
+      `  return 42;`,
+      `}`,
+      `var f = new Proxy(ff, {});`,
+    ];
+    return lines.join("\n");
+  }
+
+  function g_template(g_inlinable, f_args, g_args) {
+    var g_comment = g_inlinable ? CAN_INLINE_COMMENT : DONT_INLINE_COMMENT;
+    var lines = [
+      `function g(a) {`,
+      `  ${g_comment}`,
+      `  CheckArguments([${g_args}], arguments);`,
+      `  return f(${f_args});`,
+      `}`,
+    ];
+    return lines.join("\n");
+  }
+
+  function test_template(f_source, g_source, g_args,
+                         f_inlinable, g_inlinable) {
+    f_source = ident_source(f_source, 2);
+    g_source = ident_source(g_source, 2);
+
+    var lines = [
+      `(function() {`,
+      f_source,
+      g_source,
+      `  function test() {`,
+      `    assertEquals(42, g(${g_args}));`,
+      `  }`,
+      `  ${f_inlinable ? "%SetForceInlineFlag(f)" : ""};`,
+      `  ${g_inlinable ? "%SetForceInlineFlag(g)" : ""};`,
+      ``,
+      `  test();`,
+      `  %OptimizeFunctionOnNextCall(test);`,
+      `  try { %OptimizeFunctionOnNextCall(f); } catch(e) {}`,
+      `  try { %OptimizeFunctionOnNextCall(ff); } catch(e) {}`,
+      `  %OptimizeFunctionOnNextCall(g);`,
+      `  test();`,
+      `})();`,
+      ``,
+    ];
+    var source = lines.join("\n");
+    return source;
+  }
+
+  // TODO(v8:4698), TODO(ishell): support all commented cases.
+  var f_args_variants = ["", "1", "1, 2"];
+  var g_args_variants = [/*"",*/ "10", /*"10, 20"*/];
+  var f_inlinable_variants = [/*true,*/ false];
+  var g_inlinable_variants = [true, false];
+  var f_variants = [
+      f_template_normal,
+      f_template_bound,
+      f_template_proxy
+  ];
+
+  f_variants.forEach((f_template) => {
+    f_args_variants.forEach((f_args) => {
+      g_args_variants.forEach((g_args) => {
+        f_inlinable_variants.forEach((f_inlinable) => {
+          g_inlinable_variants.forEach((g_inlinable) => {
+            var f_source = f_template(f_inlinable, f_args);
+            var g_source = g_template(g_inlinable, f_args, g_args);
+            var source = test_template(f_source, g_source, g_args,
+                                       f_inlinable, g_inlinable);
+            print("====================");
+            print(source);
+            eval(source);
+          });
+        });
+      });
+    });
+  });
+}
+
+run_tests();