test/langtools/tools/javac/parser/StringFoldingPosTest.java

/*
 * Copyright (c) 2020, Google LLC. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

/*
 * @test
 * @bug 8134007 8035787
 * @summary folded string literals should have correct start and end positions
 */

import com.sun.source.tree.CompilationUnitTree;
import com.sun.source.tree.LiteralTree;
import com.sun.source.tree.Tree;
import com.sun.source.util.JavacTask;
import com.sun.source.util.SourcePositions;
import com.sun.source.util.TreeScanner;
import com.sun.source.util.Trees;

import java.io.IOException;
import java.net.URI;
import java.util.Arrays;

import javax.tools.JavaCompiler;
import javax.tools.JavaFileObject;
import javax.tools.SimpleJavaFileObject;
import javax.tools.ToolProvider;

public class StringFoldingPosTest {
    private final JavaCompiler compiler = ToolProvider.getSystemJavaCompiler();

    public static void main(String[] args) throws IOException {
        StringFoldingPosTest t = new StringFoldingPosTest();
        JavaFileObject source =
                t.makeSource(
                        "C", "class C {String X=\"F\" + \"O\" + \"L\" + \"D\" + \"E\" + \"D\";}");
        t.run(source, "FOLDED", 18, 51);
        source =
                t.makeSource(
                        "C",
                        "class C {String X=(\"F\" + \"O\") + (\"L\" + \"D\") + (\"E\" + \"D\");}");
        t.run(source, "FO", 19, 28);
        t.run(source, "LD", 33, 42);
        t.run(source, "ED", 47, 56);
    }

    private static JavaFileObject makeSource(String name, String code) {
        return new SimpleJavaFileObject(
                URI.create(
                        "file:/" + name.replace('.', '/') + JavaFileObject.Kind.SOURCE.extension),
                JavaFileObject.Kind.SOURCE) {
            @Override
            public CharSequence getCharContent(boolean ignoreEncodingErrors) {
                return code;
            }
        };
    }

    private void run(
            JavaFileObject source,
            String expectedLiteral,
            long expectedStartPos,
            long expectedEndPos)
            throws IOException {
        JavacTask ct =
                (JavacTask) compiler.getTask(null, null, null, null, null, Arrays.asList(source));
        SourcePositions positions = Trees.instance(ct).getSourcePositions();
        Iterable<? extends CompilationUnitTree> trees = ct.parse();
        boolean[] found = {false};
        for (CompilationUnitTree tree : trees) {
            new TreeScanner<Void, Void>() {
                @Override
                public Void visitLiteral(LiteralTree literal, Void v) {
                    if (literal.getKind() == Tree.Kind.STRING_LITERAL
                            && literal.getValue().equals(expectedLiteral)) {
                        long startPos = positions.getStartPosition(tree, literal);
                        long endPos = positions.getEndPosition(tree, literal);
                        if (startPos != expectedStartPos) {
                            throw new AssertionError(
                                    "Expected start position "
                                            + expectedStartPos
                                            + ", but was "
                                            + startPos);
                        }
                        if (endPos != expectedEndPos) {
                            throw new AssertionError(
                                    "Expected end position "
                                            + expectedEndPos
                                            + ", but was "
                                            + endPos);
                        }
                        found[0] = true;
                    }
                    return null;
                }
            }.scan(trees, null);
        }
        if (found[0]) {
            return;
        }
        throw new AssertionError("Expected string literal " + expectedLiteral + " not found");
    }
}