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ima02/resources/defects4j-checkout-closure-1f/test/com/google/javascript/jscomp/SideEffectsAnalysisTest.java
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2023-04-25 11:33:41 +00:00

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Java

/*
* Copyright 2010 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.common.collect.ImmutableSet;
import com.google.javascript.jscomp.NodeTraversal.AbstractPostOrderCallback;
import com.google.javascript.jscomp.SideEffectsAnalysis.LocationAbstractionMode;
import com.google.javascript.rhino.Node;
/**
* Tests for {@link SideEffectsAnalysis}.
*
* @author dcc@google.com (Devin Coughlin)
*
*/
public class SideEffectsAnalysisTest extends CompilerTestCase {
private static final String SHARED_EXTERNS = "var arguments = [];";
LocationAbstractionMode currentLocationAbstractionIdentifier;
SideEffectsAnalysis currentAnalysis = null;
Compiler currentCompiler = null;
Node currentJsRoot = null;
@Override
protected CompilerPass getProcessor(final Compiler compiler) {
currentCompiler = compiler;
currentAnalysis = new SideEffectsAnalysis(compiler,
currentLocationAbstractionIdentifier);
return new CompilerPass() {
@Override
public void process(Node externs, Node root) {
if (currentLocationAbstractionIdentifier ==
LocationAbstractionMode.VISIBILITY_BASED) {
// Run var when using the visibility abstraction
// because it is unsound if it fails.
final VarCheck varCheck = new VarCheck(compiler);
varCheck.process(externs, root);
}
currentAnalysis.process(externs, root);
}
};
}
@Override
public void setUp() throws Exception {
super.setUp();
currentAnalysis = null;
currentCompiler = null;
}
public void testDegenerateSafeMoves() {
// Env is empty
assertSafeMoveDegenerate("src: 1; env: ; dest: 3;");
// Src and env pure
assertSafeMoveDegenerate("src: 1; env: 2; dest: 3;");
// Only refs
assertSafeMoveDegenerate("src: 1; env: x; dest: 3;");
assertSafeMoveDegenerate("src: x; env: 1; dest: 3;");
// Only mods
assertSafeMoveDegenerate("src: 1; env: x++; dest: 3;");
assertSafeMoveDegenerate("src: x++; env: 1; dest: 3;");
}
public void testVisibilitySafeMoves() {
// Env is empty
assertSafeMoveVisibility("src: 1; env: ; dest: 3;");
// Src and env pure
assertSafeMoveVisibility("src: 1; env: 2; dest: 3;");
// Only refs
assertSafeMoveVisibility("var x; src: 1; env: x; dest: 3;");
assertSafeMoveVisibility("var x; src: x; env: 1; dest: 3;");
// Only mods
assertSafeMoveVisibility("var x; src: 1; env: x++; dest: 3;");
assertSafeMoveVisibility("var x; src: x++; env: 1; dest: 3;");
// Source references global, env changes local
assertSafeMoveVisibility(
"var x;" +
"function f(){" +
"var y;" +
"src: x;" +
"env: y++;" +
"dest: 3;" +
"}");
// Source changes global, env refs local
assertSafeMoveVisibility(
"var x;" +
"function f(){" +
"var y;" +
"src: x++;" +
"env: y;" +
"dest: 3;" +
"}");
// Source references global, env changes local with shadowing
assertSafeMoveVisibility(
"var x;" +
"var y;" +
"function f(){" +
"var y;" +
"src: x;" +
"env: y++;" +
"dest: 3;" +
"}");
// Source changes global, env refs local with shadowing
assertSafeMoveVisibility(
"var x;" +
"var y;" +
"function f(){" +
"var y;" +
"src: x++;" +
"env: y;" +
"dest: 3;" +
"}");
// Source references captured local, env changes local
assertSafeMoveVisibility(
"function f(){" +
"var x;" +
"var y;" +
"src: x;" +
"env: y++;" +
"dest: 3;" +
"function inner() {" +
"x" +
"}" +
"}");
// Source changes captured local, env refs local
assertSafeMoveVisibility(
"function f(){" +
"var x;" +
"var y;" +
"src: x++;" +
"env: y;" +
"dest: 3;" +
"function inner() {" +
"x" +
"}" +
"}");
// Source references heap, env changes local
assertSafeMoveVisibility(
"var x = {};" +
"function f(){" +
"var y;" +
"src: x.a;" +
"env: y++;" +
"dest: 3;" +
"}");
// Source changes heap, env refs local
assertSafeMoveVisibility(
"var x = {};" +
"function f(){" +
"var y;" +
"src: x.a++;" +
"env: y;" +
"dest: 3;" +
"}");
// MOD in function expressions shouldn't count
assertSafeMoveVisibility(
"var x = {};" +
"src: x.a;" +
"env: (function() {" +
"x.a++;" +
"});" +
"dest: 3;");
// REF in function expressions shouldn't count
assertSafeMoveVisibility(
"var x = {};" +
"src: x.a++;" +
"env: (function() {" +
"x.a;" +
"});" +
"dest: 3;");
}
public void testDegenerateUnsafeMoves() {
// Unsafe to move increment across read
assertUnsafeMoveDegenerate("src: x++; env: foo(y); dest: 3;");
// Unsafe to move read across increment
assertUnsafeMoveDegenerate("src: foo(y); env: x++; dest: 3;");
// Unsafe to move write across write
assertUnsafeMoveDegenerate("src: x = 7; env: y = 3; dest:3;");
}
public void testVisibilityUnsafeMoves() {
// Unsafe to move increment across read for global variables
assertUnsafeMoveVisibility("var x,y; src: x++; env: y; dest: 3;");
// Unsafe to move increment across read for local variables
assertUnsafeMoveVisibility("function f() {" +
"var x,y; src: x++; env: y; dest: 3;" +
"}");
// Unsafe to move increment across read for captured local variables
assertUnsafeMoveVisibility(
"function f() {" +
"var x,y; src: x++; env: y; dest: 3;" +
"function inner() {" +
"x; y;" +
"}" +
"}");
// Unsafe to move increment across read for heap locations
assertUnsafeMoveVisibility("var x,y; src: x.a++; env: y.b; dest: 3;");
// Unsafe to move read across increment of for global variables
assertUnsafeMoveVisibility("var x,y; src: y; env: x++; dest: 3;");
// Unsafe to move read across increment for local variables
assertUnsafeMoveVisibility("function f() {" +
"var x,y; src: x; env: y++; dest: 3;" +
"}");
// Unsafe to move read across increment for captured local variables
assertUnsafeMoveVisibility(
"function f() {" +
"var x,y; src: x; env: y++; dest: 3;" +
"function inner() {" +
"x; y;" +
"}" +
"}");
// Unsafe to move read across increment for heap locations
assertUnsafeMoveVisibility("var x,y; src: x.a; env: y.b++; dest: 3;");
// Unsafe to move write across write for globals
assertUnsafeMoveVisibility("var x,y; src: x = 7; env: y = 3; dest: 3;");
// Unsafe to move write across write for local variables
assertUnsafeMoveVisibility("function f() {" +
"var x,y; src: x = 7; env: y = 3; dest: 3;" +
"}");
// Unsafe to move write across write for captured local variables
assertUnsafeMoveVisibility(
"function f() {" +
"var x,y; src: x = 7; env: y = 3; dest: 3;" +
"function inner() {" +
"x; y;" +
"}" +
"}");
// Unsafe to move write across write for heap locations
assertUnsafeMoveVisibility("var x,y; src: x.a = 7; env: y.b = 3; dest: 3;");
}
public void testVisibilityMoveCalls() {
// Interprocedural side effect analysis isn't implemented yet, so any calls
// should make movement unsafe, since we don't know what those calls are
// doing.
// TODO(dcc): implement interprocedural side effect analysis.
// Source makes call, env refs global
assertUnsafeMoveVisibility(
"var x = {};" +
"var g = function(){};" +
"function f(){" +
"var y;" +
"src: g();" +
"env: x;" +
"dest: 3;" +
"}");
// Source makes refs global, env makes call
assertUnsafeMoveVisibility(
"var x = {};" +
"var g = function(){};" +
"function f(){" +
"var y;" +
"src: x;" +
"env: g();" +
"dest: 3;" +
"}");
}
public void testVisibilityMergesParametersWithHeap() {
// For now, we expect the visibility based location abstraction
// to merge parameter variable locations with heap locations because
// parameters can be references and modified via the arguments object.
// Source changes heap, env refs parameter
assertUnsafeMoveVisibility(
"var x = {};" +
"function f(y){" +
"src: x[0]++;" +
"env: y;" +
"dest: 3;" +
"}");
// Source refs heap, env changes parameters
assertUnsafeMoveVisibility(
"var x = {};" +
"function f(y){" +
"src: x[0];" +
"env: y++;" +
"dest: 3;" +
"}");
// Source changes arguments explicitly, env refs parameter
assertUnsafeMoveVisibility(
"var x = {};" +
"function f(y){" +
"src: arguments[0]++;" +
"env: y;" +
"dest: 3;" +
"}");
// Source refs arguments explicitly, env changes parameter
assertUnsafeMoveVisibility(
"var x = {};" +
"function f(y){" +
"src: arguments[0];" +
"env: y++;" +
"dest: 3;" +
"}");
}
public void testMovedSideEffectsMustHaveSameControlFlow() {
// Safe to move within IF block
assertSafeMoveVisibility(
"var a;" +
"function f() {" +
"var l;" +
"if (l) {" +
"src: a++;" +
"env: 3;" +
"dest: 3;" +
"}" +
"}"
);
// Unsafe to move between two IF blocks
assertUnsafeMoveVisibility(
"var a;" +
"function f() {" +
"var l;" +
"if (l) {" +
"src: a++;" +
"env: 3;" +
"}" +
"if (l) {" +
"dest: 3;" +
"}" +
"}"
);
// Unsafe to move between then/else of same IF block
assertUnsafeMoveVisibility(
"var a;" +
"function f() {" +
"var l;" +
"if (l) {" +
"src: a++;" +
"env: 3;" +
"} else {" +
"dest: 3;" +
"}" +
"}"
);
// Safe to move within WHILE block
assertSafeMoveVisibility(
"var a;" +
"function f() {" +
"var l;" +
"while (l) {" +
"src: a++;" +
"env: 3;" +
"dest: 3;" +
"}" +
"}"
);
// Unsafe to move within WHILE block with BREAK
assertUnsafeMoveVisibility(
"var a;" +
"function f() {" +
"var l;" +
"while (l) {" +
"src: a++;" +
"env: l;" +
"break;" +
"dest: 3;" +
"}" +
"}"
);
// Unsafe to move within WHILE block with continue
assertUnsafeMoveVisibility(
"var a;" +
"function f() {" +
"var l;" +
"while (l) {" +
"src: a++;" +
"env: 3;" +
"continue;" +
"dest: 3;" +
"}" +
"}"
);
// Unsafe to move within WHILE block with continue
assertUnsafeMoveVisibility(
"var a;" +
"function f() {" +
"var l;" +
"while (l) {" +
"src: a++;" +
"env: 3;" +
"return;" +
"dest: 3;" +
"}" +
"}"
);
// Safe to move within DO
assertSafeMoveVisibility(
"var a;" +
"function f() {" +
"var l;" +
"do {" +
"src: a++;" +
"env: 3;" +
"dest: 3;" +
"} while(l)" +
"}"
);
// Unsafe to move outside DO
assertUnsafeMoveVisibility(
"var a;" +
"function f() {" +
"var l;" +
"do {" +
"src: a++;" +
"env: 3;" +
"} while(l)" +
"dest: 3;" +
"}"
);
// It should be safe to move within CASE
// but we disallow for now because analyzing
// CASE fall-through and BREAKs is complicated.
assertUnsafeMoveVisibility(
"var a;" +
"function f() {" +
"var l;" +
"switch(l) {" +
"case 17:" +
"src: a++;" +
"env: 3;" +
"dest: 3;" +
"break;" +
"}" +
"}"
);
// Unsafe to move between CASEs
assertUnsafeMoveVisibility(
"var a;" +
"function f() {" +
"var l;" +
"switch(l) {" +
"case 17:" +
"src: a++;" +
"env: 3;" +
"break;" +
"case 18:" +
"dest: 3;" +
"break;" +
"}" +
"}"
);
// Unsafe to move between FUNCTIONs
assertUnsafeMoveVisibility(
"var a;" +
"function f() {" +
"src: a++;" +
"env: 3;" +
"}" +
"function g() {" +
"dest: 3;" +
"}"
);
}
private SideEffectsAnalysis.AbstractMotionEnvironment environment(
Node ...nodes) {
return new SideEffectsAnalysis.RawMotionEnvironment(
ImmutableSet.copyOf(nodes));
}
private void assertMove(LocationAbstractionMode abstraction,
String src,
boolean expected) {
SideEffectsAnalysis analysis = compileAndRun(src, abstraction);
Node sourceNode = findLabeledStatement("src");
Node environmentNode = findLabeledStatement("env");
Node destinationNode = findLabeledStatement("dest");
boolean result = analysis.safeToMoveBefore(sourceNode,
environment(environmentNode), destinationNode);
if (expected) {
assertTrue(result);
} else {
assertFalse(result);
}
}
private void assertSafeMoveDegenerate(String src) {
assertMove(LocationAbstractionMode.DEGENERATE, src, true);
}
private void assertUnsafeMoveDegenerate(String src) {
assertMove(LocationAbstractionMode.DEGENERATE, src, false);
}
private void assertSafeMoveVisibility(String src) {
assertMove(LocationAbstractionMode.VISIBILITY_BASED, src, true);
}
private void assertUnsafeMoveVisibility(String src) {
assertMove(LocationAbstractionMode.VISIBILITY_BASED, src, false);
}
private SideEffectsAnalysis compileAndRun(String js,
LocationAbstractionMode locationAbstractionIdentifier) {
currentLocationAbstractionIdentifier = locationAbstractionIdentifier;
testSame(SHARED_EXTERNS, js, null);
currentJsRoot = currentCompiler.jsRoot;
return currentAnalysis;
}
// Shamelessly stolen from NameReferenceGraphConstructionTest
private Node findLabeledStatement(String label) {
LabeledStatementSearcher s = new LabeledStatementSearcher(label);
new NodeTraversal(currentCompiler, s).traverse(currentCompiler.jsRoot);
assertNotNull("Label " + label + " should be in the source code", s.found);
return s.found;
}
/**
* Quick traversal to find a given labeled statement in the AST.
*
* Given "foo", finds the statement a = x in
* foo: a = x;
*/
private class LabeledStatementSearcher extends AbstractPostOrderCallback {
Node found = null;
final String target;
LabeledStatementSearcher(String target) {
this.target = target;
}
@Override
public void visit(NodeTraversal t, Node n, Node parent) {
if (n.isLabel() &&
target.equals(n.getFirstChild().getString())) {
found = n.getLastChild();
}
}
}
}