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/*
* Copyright 2008 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;
import com.google.javascript.jscomp.NodeTraversal.AbstractPostOrderCallback;
import com.google.javascript.rhino.Node;
import junit.framework.TestCase;
/**
* Tests for {@link MustBeReachingVariableDef}.
*
*/
public class MustBeReachingVariableDefTest extends TestCase {
private MustBeReachingVariableDef defUse = null;
private Node def = null;
private Node use = null;
public static final String EXTERNS = "var goog = {}";
public void testStraightLine() {
assertMatch("D:var x=1; U: x");
assertMatch("var x; D:x=1; U: x");
assertNotMatch("D:var x=1; x = 2; U: x");
assertMatch("var x=1; D:x=2; U: x");
assertNotMatch("U:x; D:var x = 1");
assertNotMatch("D:var x; U:x; x=1");
assertNotMatch("D:var x; U:x; x=1; x");
assertMatch("D: var x = 1; var y = 2; y; U:x");
}
public void testIf() {
assertNotMatch("var x; if(a){ D:x=1 } else { x=2 }; U:x");
assertNotMatch("var x; if(a){ x=1 } else { D:x=2 }; U:x");
assertMatch("D:var x=1; if(a){ U:x } else { x };");
assertMatch("D:var x=1; if(a){ x } else { U:x };");
assertNotMatch("var x; if(a) { D: x = 1 }; U:x;");
}
public void testLoops() {
assertNotMatch("var x=0; while(a){ D:x=1 }; U:x");
assertNotMatch("var x=0; for(;;) { D:x=1 }; U:x");
assertMatch("D:var x=1; while(a) { U:x }");
assertMatch("D:var x=1; for(;;) { U:x }");
}
public void testConditional() {
assertMatch("var x=0,y; D:(x=1)&&y; U:x");
assertNotMatch("var x=0,y; D:y&&(x=1); U:x");
}
public void testUseAndDefInSameInstruction() {
assertMatch("D:var x=0; U:x=1,x");
assertMatch("D:var x=0; U:x,x=1");
}
public void testAssignmentInExpressions() {
assertMatch("var x=0; D:foo(bar(x=1)); U:x");
assertMatch("var x=0; D:foo(bar + (x = 1)); U:x");
}
public void testHook() {
assertNotMatch("var x=0; D:foo() ? x=1 : bar(); U:x");
assertNotMatch("var x=0; D:foo() ? x=1 : x=2; U:x");
}
public void testExpressionVariableReassignment() {
assertMatch("var a,b; D: var x = a + b; U:x");
assertNotMatch("var a,b,c; D: var x = a + b; a = 1; U:x");
assertNotMatch("var a,b,c; D: var x = a + b; f(b = 1); U:x");
assertMatch("var a,b,c; D: var x = a + b; c = 1; U:x");
// Even if the sub-expression is change conditionally
assertNotMatch("var a,b,c; D: var x = a + b; c ? a = 1 : 0; U:x");
}
public void testMergeDefinitions() {
assertNotMatch("var x,y; D: y = x + x; if(x) { x = 1 }; U:y");
}
public void testMergesWithOneDefinition() {
assertNotMatch(
"var x,y; while(y) { if (y) { print(x) } else { D: x = 1 } } U:x");
}
public void testRedefinitionUsingItself() {
assertMatch("var x = 1; D: x = x + 1; U:x;");
assertNotMatch("var x = 1; D: x = x + 1; x = 1; U:x;");
}
public void testMultipleDefinitionsWithDependence() {
assertMatch("var x, a, b; D: x = a, x = b; U: x");
assertMatch("var x, a, b; D: x = a, x = b; a = 1; U: x");
assertNotMatch("var x, a, b; D: x = a, x = b; b = 1; U: x");
}
public void testExterns() {
assertNotMatch("D: goog = {}; U: goog");
}
public void testAssignmentOp() {
assertMatch("var x = 0; D: x += 1; U: x");
assertMatch("var x = 0; D: x *= 1; U: x");
assertNotMatch("D: var x = 0; x += 1; U: x");
}
public void testIncAndDec() {
assertMatch("var x; D: x++; U: x");
assertMatch("var x; D: x--; U: x");
}
public void testFunctionParams1() {
computeDefUse("if (param2) { D: param1 = 1; U: param1 }");
assertSame(def, defUse.getDefNode("param1", use));
}
public void testFunctionParams2() {
computeDefUse("if (param2) { D: param1 = 1} U: param1");
assertNotSame(def, defUse.getDefNode("param1", use));
}
public void testArgumentsObjectModifications() {
computeDefUse("D: param1 = 1; arguments[0] = 2; U: param1");
assertNotSame(def, defUse.getDefNode("param1", use));
}
public void testArgumentsObjectEscaped() {
computeDefUse("D: param1 = 1; var x = arguments; x[0] = 2; U: param1");
assertNotSame(def, defUse.getDefNode("param1", use));
}
public void testArgumentsObjectEscapedDependents() {
assertNotMatch("param1=1; var x; D:x=param1; var y=arguments; U:x");
}
/**
* The use of x at U: is the definition of x at D:.
*/
private void assertMatch(String src) {
computeDefUse(src);
assertSame(def, defUse.getDefNode("x", use));
}
/**
* The use of x at U: is not the definition of x at D:.
*/
private void assertNotMatch(String src) {
computeDefUse(src);
assertNotSame(def, defUse.getDefNode("x", use));
}
/**
* Computes reaching definition on given source.
*/
private void computeDefUse(String src) {
Compiler compiler = new Compiler();
src = "function _FUNCTION(param1, param2){" + src + "}";
Node root = compiler.parseTestCode(src).getFirstChild();
assertEquals(0, compiler.getErrorCount());
Scope scope = new SyntacticScopeCreator(compiler).createScope(root, null);
ControlFlowAnalysis cfa = new ControlFlowAnalysis(compiler, false, true);
cfa.process(null, root);
ControlFlowGraph<Node> cfg = cfa.getCfg();
defUse = new MustBeReachingVariableDef(cfg, scope, compiler);
defUse.analyze();
def = null;
use = null;
new NodeTraversal(compiler,new LabelFinder()).traverse(root);
assertNotNull("Code should have an instruction labeled D", def);
assertNotNull("Code should have an instruction labeled U", use);
}
/**
* Finds the D: and U: label and store which node they point to.
*/
private class LabelFinder extends AbstractPostOrderCallback {
@Override
public void visit(NodeTraversal t, Node n, Node parent) {
if (n.isLabel()) {
if (n.getFirstChild().getString().equals("D")) {
def = n.getLastChild();
} else if (n.getFirstChild().getString().equals("U")) {
use = n.getLastChild();
}
}
}
}
}
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