Bug 576829 - Fix evaluations for variables with recursive genericI20211101-1800

The variable types received from the debugger doesn't contains the
correct generic bounds nor type params for recursive type params, this
cause a compilation issue in the generated snippet source. The fix tries
to find the correct generic types/bounds from the AST and apply them
into variables that are added into generated eval method.

Change-Id: Ie136a4a54d6e855d75d717380e9086f1d296a115
Signed-off-by: Gayan Perera <gayanper@gmail.com>
Reviewed-on: https://git.eclipse.org/r/c/jdt/eclipse.jdt.debug/+/187132
Tested-by: JDT Bot <jdt-bot@eclipse.org>
Reviewed-by: Sarika Sinha <sarika.sinha@in.ibm.com>

4 files changed, 38 insertions, 1 deletions

diff --git a/org.eclipse.jdt.debug.tests/java7/Bug576829.java b/org.eclipse.jdt.debug.tests/java7/Bug576829.java
new file mode 100644
index 000000000..4d0aad584
--- /dev/null
+++ b/org.eclipse.jdt.debug.tests/java7/Bug576829.java
@@ -0,0 +1,20 @@
+import java.util.ArrayList;
+import java.util.List;
+
+import Bug576829.MyClass;
+
+public class Bug576829 {
+	
+	public static void main(String[] args) {
+		MyClass<?> cls = new MyClass<>();
+		List<? extends Number> num = new ArrayList<>();
+		System.out.println("x"); // add conditional breakpoint here (e.g. "cls.getBoolean()")
+	}
+	
+	private static class MyClass<T extends MyClass<T>> {
+		
+		public boolean getBoolean() {
+			return false;
+		}
+	}
+}
\ No newline at end of file
diff --git a/org.eclipse.jdt.debug.tests/tests/org/eclipse/jdt/debug/tests/AbstractDebugTest.java b/org.eclipse.jdt.debug.tests/tests/org/eclipse/jdt/debug/tests/AbstractDebugTest.java
index b879fab5c..f2fcc6842 100644
--- a/org.eclipse.jdt.debug.tests/tests/org/eclipse/jdt/debug/tests/AbstractDebugTest.java
+++ b/org.eclipse.jdt.debug.tests/tests/org/eclipse/jdt/debug/tests/AbstractDebugTest.java
@@ -440,6 +440,7 @@ public abstract class AbstractDebugTest extends TestCase implements  IEvaluation
 				cfgs.add(createLaunchConfiguration(jp, "ThreadNameChange"));
 				cfgs.add(createLaunchConfiguration(jp, "Bug567801"));
 				cfgs.add(createLaunchConfiguration(jp, "Bug572782"));
+				cfgs.add(createLaunchConfiguration(jp, "Bug576829"));
 	    		loaded17 = true;
 	    		waitForBuild();
 	        }
diff --git a/org.eclipse.jdt.debug.tests/tests/org/eclipse/jdt/debug/tests/eval/GenericsEval17Test.java b/org.eclipse.jdt.debug.tests/tests/org/eclipse/jdt/debug/tests/eval/GenericsEval17Test.java
index c4c32fef7..de80380e6 100644
--- a/org.eclipse.jdt.debug.tests/tests/org/eclipse/jdt/debug/tests/eval/GenericsEval17Test.java
+++ b/org.eclipse.jdt.debug.tests/tests/org/eclipse/jdt/debug/tests/eval/GenericsEval17Test.java
@@ -117,6 +117,18 @@ public class GenericsEval17Test extends AbstractDebugTest {
 		assertEquals("value is not 3", "3", value.getValueString());
 	}
 
+	public void testEvaluate_Bug576829_RecursiveGenerics_ObjectInstanceEvaluation() throws Exception {
+		createConditionalLineBreakpoint(11, "Bug576829", "cls.getBoolean() && num.isEmpty()", false);
+		javaThread = launchToBreakpoint("Bug576829");
+		assertNotNull("The program did not suspend", javaThread);
+
+		String snippet = "cls.getBoolean() && num.isEmpty()";
+		IValue value = doEval(javaThread, snippet);
+
+		assertNotNull("value is null", value);
+		assertEquals("value is not false", "false", value.getValueString());
+	}
+
 	private void debugWithBreakpoint(String testClass, int lineNumber) throws Exception {
 		createLineBreakpoint(lineNumber, testClass);
 		javaThread = launchToBreakpoint(testClass);
diff --git a/org.eclipse.jdt.debug/eval/org/eclipse/jdt/internal/debug/eval/ast/engine/ASTEvaluationEngine.java b/org.eclipse.jdt.debug/eval/org/eclipse/jdt/internal/debug/eval/ast/engine/ASTEvaluationEngine.java
index dc3a3eef3..82f5ff9fd 100644
--- a/org.eclipse.jdt.debug/eval/org/eclipse/jdt/internal/debug/eval/ast/engine/ASTEvaluationEngine.java
+++ b/org.eclipse.jdt.debug/eval/org/eclipse/jdt/internal/debug/eval/ast/engine/ASTEvaluationEngine.java
@@ -428,7 +428,6 @@ public class ASTEvaluationEngine implements IAstEvaluationEngine {
 		 */
 		if (genericSignature.startsWith(String.valueOf(Signature.C_TYPE_VARIABLE)) ||
 				genericSignature.startsWith(String.valueOf(Signature.C_CAPTURE)) ||
-				genericSignature.startsWith(String.valueOf(Signature.C_STAR)) ||
 				genericSignature.startsWith(String.valueOf(Signature.C_SUPER)))
 		{
 			fixedSignature.append(toDotQualified(erasureSignature));
@@ -445,6 +444,11 @@ public class ASTEvaluationEngine implements IAstEvaluationEngine {
 
 		String[] typeArguments = Signature.getTypeArguments(genericSignature);
 		if (typeArguments.length > 0) {
+			if (typeArguments.length == 1 && typeArguments[0].equals(String.valueOf(Signature.C_STAR))) {
+				// this is when we have recursive generics, so remove the generics to avoid compilation issues.
+				return;
+			}
+
 			fixedSignature.append(Signature.C_GENERIC_START);
 			for (int i = 0; i < typeArguments.length; i++) {
 				if (i > 0) {