Automated g4 rollback of changelist 116101354.

tap-prod · blickly · commit a5166e487bb9 · 2016-03-02T12:01:35.000-08:00
*** Reason for rollback *** 500 or more targets failed to build *** Original change description *** Remove the `arguments` usage check. Users never really liked it, and the primary motivation for creating it is a non-issue now that 6a40212 is submitted. *** ------------- Created by MOE: https://github.com/google/moe MOE_MIGRATED_REVID=116103285
diff --git a/src/com/google/javascript/jscomp/DefaultPassConfig.java b/src/com/google/javascript/jscomp/DefaultPassConfig.java
@@ -31,6 +31,7 @@
 import com.google.javascript.jscomp.ExtractPrototypeMemberDeclarations.Pattern;
 import com.google.javascript.jscomp.NodeTraversal.Callback;
 import com.google.javascript.jscomp.PassFactory.HotSwapPassFactory;
+import com.google.javascript.jscomp.lint.CheckArguments;
 import com.google.javascript.jscomp.lint.CheckDuplicateCase;
 import com.google.javascript.jscomp.lint.CheckEmptyStatements;
 import com.google.javascript.jscomp.lint.CheckEnums;
@@ -1557,6 +1558,7 @@ protected HotSwapCompilerPass create(AbstractCompiler compiler) {
     @Override
     protected HotSwapCompilerPass create(AbstractCompiler compiler) {
       ImmutableList.Builder<Callback> callbacks = ImmutableList.<Callback>builder()
+          .add(new CheckArguments(compiler))
           .add(new CheckEmptyStatements(compiler))
           .add(new CheckEnums(compiler))
           .add(new CheckInterfaces(compiler))
diff --git a/src/com/google/javascript/jscomp/DiagnosticGroups.java b/src/com/google/javascript/jscomp/DiagnosticGroups.java
@@ -20,6 +20,7 @@
 import com.google.common.base.Preconditions;
 import com.google.common.collect.ImmutableMap;
 import com.google.common.collect.ImmutableSet;
+import com.google.javascript.jscomp.lint.CheckArguments;
 import com.google.javascript.jscomp.lint.CheckDuplicateCase;
 import com.google.javascript.jscomp.lint.CheckEmptyStatements;
 import com.google.javascript.jscomp.lint.CheckEnums;
@@ -467,6 +468,7 @@ public DiagnosticGroup forName(String name) {
   // provide optional suggestions.
   public static final DiagnosticGroup LINT_CHECKS =
       DiagnosticGroups.registerGroup("lintChecks", // undocumented
+          CheckArguments.BAD_ARGUMENTS_USAGE,
           CheckEmptyStatements.USELESS_EMPTY_STATEMENT,
           CheckEnums.COMPUTED_PROP_NAME_IN_ENUM,
           CheckEnums.DUPLICATE_ENUM_VALUE,
diff --git a/src/com/google/javascript/jscomp/LintPassConfig.java b/src/com/google/javascript/jscomp/LintPassConfig.java
@@ -17,6 +17,7 @@
 
 import com.google.common.collect.ImmutableList;
 import com.google.javascript.jscomp.NodeTraversal.Callback;
+import com.google.javascript.jscomp.lint.CheckArguments;
 import com.google.javascript.jscomp.lint.CheckDuplicateCase;
 import com.google.javascript.jscomp.lint.CheckEmptyStatements;
 import com.google.javascript.jscomp.lint.CheckEnums;
@@ -106,6 +107,7 @@ protected CompilerPass create(AbstractCompiler compiler) {
           return new CombinedCompilerPass(
               compiler,
               ImmutableList.<Callback>of(
+                  new CheckArguments(compiler),
                   new CheckDuplicateCase(compiler),
                   new CheckEmptyStatements(compiler),
                   new CheckEnums(compiler),
diff --git a/src/com/google/javascript/jscomp/lint/CheckArguments.java b/src/com/google/javascript/jscomp/lint/CheckArguments.java
@@ -0,0 +1,86 @@
+/*
+ * Copyright 2015 The Closure Compiler Authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.google.javascript.jscomp.lint;
+
+import com.google.javascript.jscomp.AbstractCompiler;
+import com.google.javascript.jscomp.CompilerPass;
+import com.google.javascript.jscomp.DiagnosticType;
+import com.google.javascript.jscomp.JSError;
+import com.google.javascript.jscomp.NodeTraversal;
+import com.google.javascript.jscomp.NodeTraversal.AbstractPostOrderCallback;
+import com.google.javascript.jscomp.Var;
+import com.google.javascript.rhino.Node;
+
+
+/**
+ * Check for the 'arguments' object being used in ways which are unlikely to be optimized well,
+ * and which we cannot transpile correctly.
+ */
+public final class CheckArguments extends AbstractPostOrderCallback implements CompilerPass {
+  public static final DiagnosticType BAD_ARGUMENTS_USAGE =
+      DiagnosticType.warning(
+          "JSC_BAD_ARGUMENTS_USAGE",
+          "This use of the 'arguments' object is discouraged. See "
+              + "https://github.com/google/closure-compiler/wiki/Lint-warning-about-%60arguments%60");
+
+  private final AbstractCompiler compiler;
+
+  public CheckArguments(AbstractCompiler compiler) {
+    this.compiler = compiler;
+  }
+
+  @Override
+  public void process(Node externs, Node root) {
+    NodeTraversal.traverseEs6(compiler, root, this);
+  }
+
+  @Override
+  public void visit(NodeTraversal t, Node n, Node parent) {
+    if (!n.isName()) {
+      return;
+    }
+
+    Var var = t.getScope().getVar(n.getString());
+    if (var != null && var.isArguments()) {
+      checkArgumentsUsage(n, parent);
+    }
+  }
+
+  private void checkArgumentsUsage(Node arguments, Node parent) {
+    if (parent.isSpread()
+        || (parent.isGetProp() && parent.matchesQualifiedName("arguments.length"))
+        || (parent.isForOf() && arguments == parent.getSecondChild())
+        || (parent.isGetElem() && arguments == parent.getFirstChild())) {
+      // No warning.
+      return;
+    }
+
+    if (parent.isCall() && arguments == parent.getLastChild()) {
+      Node callee = parent.getFirstChild();
+      if (callee.isGetProp() && callee.getLastChild().getString().equals("apply")) {
+        // Probably a call to Function.apply(), so don't warn.
+        return;
+      }
+    }
+
+    report(arguments);
+  }
+
+  private void report(Node arguments) {
+    compiler.report(JSError.make(arguments, BAD_ARGUMENTS_USAGE));
+  }
+}
+
diff --git a/test/com/google/javascript/jscomp/lint/CheckArgumentsTest.java b/test/com/google/javascript/jscomp/lint/CheckArgumentsTest.java
@@ -0,0 +1,51 @@
+/*
+ * Copyright 2015 The Closure Compiler Authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.google.javascript.jscomp.lint;
+
+import static com.google.javascript.jscomp.lint.CheckArguments.BAD_ARGUMENTS_USAGE;
+
+import com.google.javascript.jscomp.Compiler;
+import com.google.javascript.jscomp.CompilerPass;
+import com.google.javascript.jscomp.Es6CompilerTestCase;
+
+public final class CheckArgumentsTest extends Es6CompilerTestCase {
+  @Override
+  public CompilerPass getProcessor(Compiler compiler) {
+    return new CheckArguments(compiler);
+  }
+
+  public void testCheckArguments_noWarning() {
+    testSameEs6("function f() { for (let a of arguments) {} }");
+    testSameEs6("function f() { return [...arguments]; }");
+    testSameEs6("function f() { return arguments[1]; }");
+    testSameEs6("function f() { for (var i=0; i<arguments.length; i++) alert(arguments[i]); }");
+  }
+
+  public void testCheckArguments_exceptionForApply() {
+    testSameEs6("function f() { g.apply(this, arguments); }");
+    testSameEs6("function f() { Function.prototype.call.apply(arguments); }");
+  }
+
+  public void testCheckArguments_warning() {
+    testWarning("function f() { g(arguments); }", BAD_ARGUMENTS_USAGE);
+    testWarning("function f() { var args = arguments; }", BAD_ARGUMENTS_USAGE);
+    testWarning("function f() { var args = [0, 1, arguments]; }", BAD_ARGUMENTS_USAGE);
+    testWarning("function f() { arguments.caller; }", BAD_ARGUMENTS_USAGE);
+    testWarning("function f() { arguments.callee; }", BAD_ARGUMENTS_USAGE);
+    testWarning("function f() { for (var i in arguments) {} }", BAD_ARGUMENTS_USAGE);
+  }
+}
