Bug 285379 - [content assist] infinite loop

- patch originally from Satyam

Change-Id: If7cb213e5fa199a6744269452a6d6fe8a6437c88

6 files changed, 153 insertions, 1 deletions

diff --git a/org.eclipse.jdt.core.tests.model/src/org/eclipse/jdt/core/tests/model/CompletionTests.java b/org.eclipse.jdt.core.tests.model/src/org/eclipse/jdt/core/tests/model/CompletionTests.java
index 304d2120df..b5300fad77 100644
--- a/org.eclipse.jdt.core.tests.model/src/org/eclipse/jdt/core/tests/model/CompletionTests.java
+++ b/org.eclipse.jdt.core.tests.model/src/org/eclipse/jdt/core/tests/model/CompletionTests.java
@@ -43,7 +43,7 @@ import org.eclipse.jdt.internal.core.eval.EvaluationContextWrapper;
 public class CompletionTests extends AbstractJavaModelCompletionTests {
 
 static {
-//	TESTS_NAMES = new String[] { "testCompletionMethodDeclaration17"};
+	TESTS_NAMES = new String[] { "test285379"};
 }
 public static Test suite() {
 	return buildModelTestSuite(CompletionTests.class, BYTECODE_DECLARATION_ORDER);
@@ -20584,6 +20584,66 @@ public void test270437c() throws JavaModelException {
 			requestor.getResults());
 }
 
+/*
+ * https://bugs.eclipse.org/bugs/show_bug.cgi?id=285379
+ */
+public void test285379a() throws JavaModelException {
+	CompletionTestsRequestor requestor = new CompletionTestsRequestor();
+	ICompilationUnit cu= getCompilationUnit("Completion", "src", "", "Completion285379.java");
+
+	String str = cu.getSource();
+	String completeBehind = "pkgtest285379.X1.";
+	int cursorLocation = str.indexOf(completeBehind) + completeBehind.length();
+	cu.codeComplete(cursorLocation, requestor);
+
+	// just not hang...	
+}
+
+/*
+ * https://bugs.eclipse.org/bugs/show_bug.cgi?id=285379
+ */
+public void test285379b() throws JavaModelException {
+	CompletionTestsRequestor requestor = new CompletionTestsRequestor();
+	ICompilationUnit cu= getCompilationUnit("Completion", "src", "", "Completion285379.java");
+
+	String str = cu.getSource();
+	String completeBehind = "return ";
+	int cursorLocation = str.indexOf(completeBehind) + completeBehind.length();
+	cu.codeComplete(cursorLocation, requestor);
+
+	// just not hang...	
+}
+
+/*
+ * https://bugs.eclipse.org/bugs/show_bug.cgi?id=285379
+ */
+public void test285379c() throws JavaModelException {
+	CompletionTestsRequestor requestor = new CompletionTestsRequestor();
+	ICompilationUnit cu= getCompilationUnit("Completion", "src", "", "Completion285379.java");
+
+	String str = cu.getSource();
+	String completeBehind = "equals";
+	int cursorLocation = str.indexOf(completeBehind) + completeBehind.length();
+	cu.codeComplete(cursorLocation, requestor);
+
+	// just not hang...	
+}
+
+/*
+ * https://bugs.eclipse.org/bugs/show_bug.cgi?id=285379
+ */
+public void test285379d() throws JavaModelException {
+	CompletionTestsRequestor requestor = new CompletionTestsRequestor();
+	ICompilationUnit cu= getCompilationUnit("Completion", "src", "", "Completion285379.java");
+
+	String str = cu.getSource();
+	String completeBehind = "(var";
+	int cursorLocation = str.indexOf(completeBehind) + completeBehind.length();
+	cu.codeComplete(cursorLocation, requestor);
+
+	// just not hang...	
+}
+
 // https://bugs.eclipse.org/bugs/show_bug.cgi?id=270436
 public void test270436a() throws JavaModelException {
 	// This test is to ensure that an interface is not offered as a choice when expecting a class.
diff --git a/org.eclipse.jdt.core.tests.model/workspace/Completion/.classpath b/org.eclipse.jdt.core.tests.model/workspace/Completion/.classpath
index f1fe1cfc51..af46168d37 100644
--- a/org.eclipse.jdt.core.tests.model/workspace/Completion/.classpath
+++ b/org.eclipse.jdt.core.tests.model/workspace/Completion/.classpath
@@ -11,6 +11,7 @@
     <classpathentry kind="lib" path="constructors.jar" sourcepath="/Completion/constructorssrc.zip"/>
     <classpathentry kind="lib" path="generics.jar" sourcepath="/Completion/genericssrc.zip"/>
     <classpathentry kind="lib" path="bug185318.jar"/>
+    <classpathentry kind="lib" path="test285379.jar"/>
     <classpathentry kind="lib" path="class-folder"/>
     <classpathentry kind="output" path="bin"/>
 </classpath>
diff --git a/org.eclipse.jdt.core.tests.model/workspace/Completion/src/Completion285379.java b/org.eclipse.jdt.core.tests.model/workspace/Completion/src/Completion285379.java
new file mode 100644
index 0000000000..53d98a004d
--- /dev/null
+++ b/org.eclipse.jdt.core.tests.model/workspace/Completion/src/Completion285379.java
@@ -0,0 +1,26 @@
+import pkgtest285379.X1;
+public class Completion285379 extends X1{
+	public interface testI{
+		void fooI();
+	};
+	X1 testVar;
+	Object o;
+	public static testI foo()
+	{
+		X1 a;
+		return 
+	}
+	public void foo1()
+	{
+		pkgtest285379.X1.
+	}
+	public boolean foo2(X1 var)
+	{
+		if (var.equals(testVar))
+			return;		
+	}
+	void bar(String var) {
+		X1 x;
+		x.equals(var);
+	}
+}
diff --git a/org.eclipse.jdt.core.tests.model/workspace/Completion/test285379.jar b/org.eclipse.jdt.core.tests.model/workspace/Completion/test285379.jar
new file mode 100644
index 0000000000..9c0a6477e6
--- /dev/null
+++ b/org.eclipse.jdt.core.tests.model/workspace/Completion/test285379.jar
diff --git a/org.eclipse.jdt.core/compiler/org/eclipse/jdt/internal/compiler/lookup/BinaryTypeBinding.java b/org.eclipse.jdt.core/compiler/org/eclipse/jdt/internal/compiler/lookup/BinaryTypeBinding.java
index e31e319b7f..03e6df4e54 100644
--- a/org.eclipse.jdt.core/compiler/org/eclipse/jdt/internal/compiler/lookup/BinaryTypeBinding.java
+++ b/org.eclipse.jdt.core/compiler/org/eclipse/jdt/internal/compiler/lookup/BinaryTypeBinding.java
@@ -1608,6 +1608,10 @@ public MethodBinding[] methods() {
 	this.tagBits |= TagBits.AreMethodsComplete;
 	return this.methods;
 }
+@Override
+public void setHierarchyCheckDone() {
+	this.tagBits |= TagBits.BeginHierarchyCheck | TagBits.EndHierarchyCheck;
+}
 
 @Override
 public TypeBinding prototype() {
@@ -2095,8 +2099,60 @@ public ReferenceBinding superclass() {
 	this.typeBits |= (this.superclass.typeBits & TypeIds.InheritableBits);
 	if ((this.typeBits & (TypeIds.BitAutoCloseable|TypeIds.BitCloseable)) != 0) // avoid the side-effects of hasTypeBit()! 
 		this.typeBits |= applyCloseableClassWhitelists();
+	detectCircularHierarchy();
 	return this.superclass;
 }
+
+private void breakLoop() {
+	ReferenceBinding currentSuper = this.superclass;
+	ReferenceBinding prevSuper = null;
+	while (currentSuper != null) {
+		if ((currentSuper.tagBits & TagBits.EndHierarchyCheck) != 0 && prevSuper instanceof BinaryTypeBinding) {
+			((BinaryTypeBinding)prevSuper).superclass = this.environment.getResolvedType(TypeConstants.JAVA_LANG_OBJECT, null);
+			break;
+		}
+		currentSuper.tagBits |= TagBits.EndHierarchyCheck;
+		prevSuper = currentSuper;
+		currentSuper = currentSuper.superclass();
+	}	
+}
+
+private void detectCircularHierarchy() {
+	ReferenceBinding currentSuper = this.superclass;
+	ReferenceBinding tempSuper = null;
+	int count = 0;
+	int skipCount = 20;
+	while (currentSuper != null) {		
+		if (currentSuper.hasHierarchyCheckStarted())
+			break;
+		if (TypeBinding.equalsEquals(currentSuper, this) || TypeBinding.equalsEquals(currentSuper, tempSuper)) {
+			currentSuper.tagBits |= TagBits.HierarchyHasProblems;
+			if (currentSuper.isBinaryBinding())
+				breakLoop();
+			
+			return;
+		}
+		if (count == skipCount) {
+			tempSuper = currentSuper; // for finding loops that only start after a linear chain
+			skipCount *= 2;
+			count = 0;
+		}
+		//Ignore if the super is not yet resolved..
+		if (!currentSuper.isHierarchyConnected()) 
+			return;
+		currentSuper = currentSuper.superclass();	
+		count++;
+	}
+	/* No loop detected and completely found that there is no loop
+	 * So, set that info for all the classes 
+	 */
+	tempSuper = this;
+	while (TypeBinding.notEquals(currentSuper, tempSuper)) {
+		tempSuper.setHierarchyCheckDone();
+		tempSuper=tempSuper.superclass();
+	}	
+}
+
 // NOTE: superInterfaces of binary types are resolved when needed
 @Override
 public ReferenceBinding[] superInterfaces() {
diff --git a/org.eclipse.jdt.core/compiler/org/eclipse/jdt/internal/compiler/lookup/ReferenceBinding.java b/org.eclipse.jdt.core/compiler/org/eclipse/jdt/internal/compiler/lookup/ReferenceBinding.java
index 537d99fbc3..98a822baae 100644
--- a/org.eclipse.jdt.core/compiler/org/eclipse/jdt/internal/compiler/lookup/ReferenceBinding.java
+++ b/org.eclipse.jdt.core/compiler/org/eclipse/jdt/internal/compiler/lookup/ReferenceBinding.java
@@ -275,6 +275,15 @@ public MethodBinding[] availableMethods() {
 	return methods();
 }
 
+public boolean hasHierarchyCheckStarted() {
+	return  (this.tagBits & TagBits.BeginHierarchyCheck) != 0;
+}
+
+public void setHierarchyCheckDone() {
+	return;
+}
+
+
 /**
  * Answer true if the receiver can be instantiated
  */