Bug 535196: [C++17] Support *this in lambda capture

Implementation and tests.

Change-Id: If32911514eb62078215b5f06be12289fa571e9a3
Signed-off-by: Hansruedi Patzen <hansruedi.patzen@hsr.ch>

core/org.eclipse.cdt.core.tests/parser/org/eclipse/cdt/core/parser/tests/ast2/DOMParserTestSuite.java

@@ -17,6 +17,7 @@ import org.eclipse.cdt.core.parser.tests.ast2.cxx14.GenericLambdaTests;
 import org.eclipse.cdt.core.parser.tests.ast2.cxx14.InitCaptureTests;
 import org.eclipse.cdt.core.parser.tests.ast2.cxx14.ReturnTypeDeductionTests;
 import org.eclipse.cdt.core.parser.tests.ast2.cxx14.VariableTemplateTests;
+import org.eclipse.cdt.core.parser.tests.ast2.cxx17.LambdaExpressionTests;
 import org.eclipse.cdt.core.parser.tests.ast2.cxx17.TemplateAutoTests;
 import org.eclipse.cdt.core.parser.tests.prefix.CompletionTestSuite;
 
@@ -69,6 +70,7 @@ public class DOMParserTestSuite extends TestCase {
 		suite.addTestSuite(InitCaptureTests.class);
 		// C++17 tests
 		suite.addTest(TemplateAutoTests.suite());
+		suite.addTestSuite(LambdaExpressionTests.class);
 		return suite;
 	}
 }

core/org.eclipse.cdt.core.tests/parser/org/eclipse/cdt/core/parser/tests/ast2/cxx17/LambdaExpressionTests.java

@@ -0,0 +1,50 @@
+/*******************************************************************************
+ * Copyright (c) 2018 Institute for Software, HSR Hochschule fuer Technik
+ * Rapperswil, University of applied sciences and others
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *     Hansruedi Patzen (IFS)
+ *******************************************************************************/
+package org.eclipse.cdt.core.parser.tests.ast2.cxx17;
+
+import org.eclipse.cdt.core.parser.tests.ast2.AST2CPPTestBase;
+
+/**
+ * AST tests for C++17 lambda changes.
+ */
+public class LambdaExpressionTests extends AST2CPPTestBase {
+	// struct S {
+	// 	void foo() {
+	// 		[*this] { }();
+	// 	}
+	// };
+	public void testLambdaCaptures_535196_1()  throws Exception {
+		parseAndCheckBindings();
+	}
+
+	// struct S {
+	// 	void bar() {
+	// 	}
+	// 	void foo() {
+	// 		[*this] { bar(); }();
+	// 	}
+	// };
+	public void testLambdaCaptures_535196_2()  throws Exception {
+		parseAndCheckBindings();
+	}
+
+	// struct S {
+	// 	void bar(int k) {
+	// 	}
+	// 	void foo() {
+	// 		[m = 3, *this] { bar(m); }();
+	// 	}
+	// };
+	public void testLambdaCaptures_535196_3()  throws Exception {
+		parseAndCheckBindings();
+	}
+}

core/org.eclipse.cdt.core.tests/parser/org/eclipse/cdt/core/parser/tests/rewrite/astwriter/ExpressionWriterTest.java

@@ -83,17 +83,30 @@ public class ExpressionWriterTest extends TestCase {
     @Test
     public void testWriteLambdaExpressionThisCaptureNoDeclarator() {
         ICPPASTLambdaExpression lambda = getEmptyLambdaExpression();
-        lambda.addCapture(new CPPASTCapture());
+        CPPASTCapture thisCapture = new CPPASTCapture();
+        thisCapture.setIsByReference(true);
+        lambda.addCapture(thisCapture);
         lambda.accept(visitor);
         String expected = "[this] {" + BR + "    return 7;" + BR + "}" + BR;
         Assert.assertEquals(expected, visitor.toString());
     }
 
+    @Test
+    public void testWriteLambdaExpressionStarThisCaptureNoDeclarator() {
+        ICPPASTLambdaExpression lambda = getEmptyLambdaExpression();
+        lambda.addCapture(new CPPASTCapture());
+        lambda.accept(visitor);
+        String expected = "[*this] {" + BR + "    return 7;" + BR + "}" + BR;
+        Assert.assertEquals(expected, visitor.toString());
+    }
+
     @Test
     public void testWriteLambdaExpressionMixedCaptureNoDeclarator() {
         ICPPASTLambdaExpression lambda = getEmptyLambdaExpression();
         lambda.setCaptureDefault(ICPPASTLambdaExpression.CaptureDefault.BY_COPY);
-        lambda.addCapture(new CPPASTCapture());
+        CPPASTCapture thisCapture = new CPPASTCapture();
+        thisCapture.setIsByReference(true);
+        lambda.addCapture(thisCapture);
         ICPPASTCapture x = new CPPASTCapture(), y = new CPPASTCapture();
         x.setIdentifier(new CPPASTName(new char[] { 'x' }));
         x.setIsByReference(true);
@@ -158,7 +171,9 @@ public class ExpressionWriterTest extends TestCase {
         y.setIsByReference(true);
         lambda.addCapture(x);
         lambda.addCapture(y);
-        lambda.addCapture(new CPPASTCapture());
+        CPPASTCapture thisCapture = new CPPASTCapture();
+        thisCapture.setIsByReference(true);
+        lambda.addCapture(thisCapture);
         f.setMutable(true);
         f.setTrailingReturnType(new CPPASTTypeId(INT, new CPPASTDeclarator(NO_NAME)));
         f.addExceptionSpecificationTypeId(new CPPASTTypeId(INT, new CPPASTDeclarator(NO_NAME)));

core/org.eclipse.cdt.core.tests/resources/rewrite/ASTWriterExpressionTestSource.awts

@@ -216,4 +216,28 @@ constexpr long double operator ""_deg(long double deg)
 int main()
 {
     double x = 90.0_deg;
-}
+}
+
+//!Star this lambda capture
+//%CPP
+struct S
+{
+    void foo()
+    {
+        [*this] {
+        }
+        ;
+    }
+};
+
+//!This lambda capture
+//%CPP
+struct S
+{
+    void foo()
+    {
+        [this] {
+        }
+        ;
+    }
+};

core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/parser/cpp/GNUCPPSourceParser.java

@@ -2122,11 +2122,18 @@ public class GNUCPPSourceParser extends AbstractGNUSourceCodeParser {
 
 		switch (LT(1)) {
 		case IToken.t_this:
+			result.setIsByReference(true);
 			return setRange(result, offset, consume().getEndOffset());
 		case IToken.tAMPER:
 			consume();
 			referenceCapture = true;
 			break;
+		case IToken.tSTAR:
+			if (LT(2) == IToken.t_this) {
+				consume();
+				return setRange(result, offset, consume().getEndOffset());
+			}
+			break;
 		}
 
 		final IASTName identifier = identifier();

core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/rewrite/astwriter/ExpressionWriter.java

@@ -570,6 +570,9 @@ public class ExpressionWriter extends NodeWriter{
 
 	private void writeCapture(ICPPASTCapture capture) {
 		if (capture.capturesThisPointer()) {
+			if (!capture.isByReference()) {
+				scribe.print(STAR_OP);
+			}
 			scribe.print(THIS);
 		} else {
 			if (capture instanceof ICPPASTInitCapture) {