8035787: SourcePositions are wrong for Strings concatenated with '+' …

…operator

Backport-of: 25642dd

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

@@ -0,0 +1,121 @@
+/*
+ * 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");
+    }
+}