Bug 573632 - Content assist is not working anymore after "if"

Change-Id: I3eb8a982fda8fbf5f70be5ce4dff647b94184d13
Signed-off-by: Stephan Herrmann <stephan.herrmann@berlin.de>
Reviewed-on: https://git.eclipse.org/r/c/jdt/eclipse.jdt.core/+/180822
Tested-by: Jay Arthanareeswaran <jarthana@in.ibm.com>
Reviewed-by: Jay Arthanareeswaran <jarthana@in.ibm.com>

3 files changed, 226 insertions, 6 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 ec723935d3..4d57bdc8a3 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
@@ -26078,4 +26078,157 @@ public void testBug496354() throws Exception {
 	        "val2[ANNOTATION_ATTRIBUTE_REF]{val2=, LT;, I, val2, null, 52}",
 			requestor.getResults());
 }
+public void testBug573632() throws Exception {
+	this.workingCopies = new ICompilationUnit[1];
+	this.workingCopies[0] = getWorkingCopy(
+			"Completion/src/Foo.java",
+			"package test;\n" +
+			"public class Foo {\n" +
+			"	Foo f;\n" +
+			"	public void foo() {\n" +
+			"		if (f != null) {\n" +
+			"			f.\n" +
+			"			f = null;\n" +
+			"		}\n" +
+			"	};\n" +
+			"}\n");
+
+	CompletionTestsRequestor2 requestor = new CompletionTestsRequestor2(true);
+	requestor.allowAllRequiredProposals();
+	String str = this.workingCopies[0].getSource();
+	String completeBehind = "f.";
+	int cursorLocation = str.lastIndexOf(completeBehind) + completeBehind.length();
+	this.workingCopies[0].codeComplete(cursorLocation, requestor, this.wcOwner);
+	assertResults(
+			"clone[METHOD_REF]{clone(), Ljava.lang.Object;, ()Ljava.lang.Object;, clone, null, 60}\n" +
+			"equals[METHOD_REF]{equals(), Ljava.lang.Object;, (Ljava.lang.Object;)Z, equals, (obj), 60}\n" +
+			"f[FIELD_REF]{f, LFoo;, LFoo;, f, null, 60}\n" +
+			"finalize[METHOD_REF]{finalize(), Ljava.lang.Object;, ()V, finalize, null, 60}\n" +
+			"foo[METHOD_REF]{foo(), LFoo;, ()V, foo, null, 60}\n" +
+			"getClass[METHOD_REF]{getClass(), Ljava.lang.Object;, ()Ljava.lang.Class;, getClass, null, 60}\n" +
+			"hashCode[METHOD_REF]{hashCode(), Ljava.lang.Object;, ()I, hashCode, null, 60}\n" +
+			"notify[METHOD_REF]{notify(), Ljava.lang.Object;, ()V, notify, null, 60}\n" +
+			"notifyAll[METHOD_REF]{notifyAll(), Ljava.lang.Object;, ()V, notifyAll, null, 60}\n" +
+			"toString[METHOD_REF]{toString(), Ljava.lang.Object;, ()Ljava.lang.String;, toString, null, 60}\n" +
+			"wait[METHOD_REF]{wait(), Ljava.lang.Object;, ()V, wait, null, 60}\n" +
+			"wait[METHOD_REF]{wait(), Ljava.lang.Object;, (J)V, wait, (millis), 60}\n" +
+			"wait[METHOD_REF]{wait(), Ljava.lang.Object;, (JI)V, wait, (millis, nanos), 60}",
+			requestor.getResults());
+}
+public void testBug573632a() throws Exception {
+	// variation: nested ifs
+	this.workingCopies = new ICompilationUnit[1];
+	this.workingCopies[0] = getWorkingCopy(
+			"Completion/src/Foo.java",
+			"package test;\n" +
+			"public class Foo {\n" +
+			"	Foo f;\n" +
+			"	public void foo() {\n" +
+			"		if (f != null) {\n" +
+			"			if (f != null) {\n" +
+			"				f.\n" +
+			"				f = null;\n" +
+			"			}\n" +
+			"		}\n" +
+			"	};\n" +
+			"}\n");
+
+	CompletionTestsRequestor2 requestor = new CompletionTestsRequestor2(true);
+	requestor.allowAllRequiredProposals();
+	String str = this.workingCopies[0].getSource();
+	String completeBehind = "f.";
+	int cursorLocation = str.lastIndexOf(completeBehind) + completeBehind.length();
+	this.workingCopies[0].codeComplete(cursorLocation, requestor, this.wcOwner);
+	assertResults(
+			"clone[METHOD_REF]{clone(), Ljava.lang.Object;, ()Ljava.lang.Object;, clone, null, 60}\n" +
+			"equals[METHOD_REF]{equals(), Ljava.lang.Object;, (Ljava.lang.Object;)Z, equals, (obj), 60}\n" +
+			"f[FIELD_REF]{f, LFoo;, LFoo;, f, null, 60}\n" +
+			"finalize[METHOD_REF]{finalize(), Ljava.lang.Object;, ()V, finalize, null, 60}\n" +
+			"foo[METHOD_REF]{foo(), LFoo;, ()V, foo, null, 60}\n" +
+			"getClass[METHOD_REF]{getClass(), Ljava.lang.Object;, ()Ljava.lang.Class;, getClass, null, 60}\n" +
+			"hashCode[METHOD_REF]{hashCode(), Ljava.lang.Object;, ()I, hashCode, null, 60}\n" +
+			"notify[METHOD_REF]{notify(), Ljava.lang.Object;, ()V, notify, null, 60}\n" +
+			"notifyAll[METHOD_REF]{notifyAll(), Ljava.lang.Object;, ()V, notifyAll, null, 60}\n" +
+			"toString[METHOD_REF]{toString(), Ljava.lang.Object;, ()Ljava.lang.String;, toString, null, 60}\n" +
+			"wait[METHOD_REF]{wait(), Ljava.lang.Object;, ()V, wait, null, 60}\n" +
+			"wait[METHOD_REF]{wait(), Ljava.lang.Object;, (J)V, wait, (millis), 60}\n" +
+			"wait[METHOD_REF]{wait(), Ljava.lang.Object;, (JI)V, wait, (millis, nanos), 60}",
+			requestor.getResults());
+}
+public void testBug573632b() throws Exception {
+	// variation: for
+	this.workingCopies = new ICompilationUnit[1];
+	this.workingCopies[0] = getWorkingCopy(
+			"Completion/src/Foo.java",
+			"package test;\n" +
+			"public class Foo {\n" +
+			"	Foo f;\n" +
+			"	public void foo() {\n" +
+			"		for (int i = 0; f != null; i++) {\n" +
+			"			f.\n" +
+			"			f = null;\n" +
+			"		}\n" +
+			"	};\n" +
+			"}\n");
+
+	CompletionTestsRequestor2 requestor = new CompletionTestsRequestor2(true);
+	requestor.allowAllRequiredProposals();
+	String str = this.workingCopies[0].getSource();
+	String completeBehind = "f.";
+	int cursorLocation = str.lastIndexOf(completeBehind) + completeBehind.length();
+	this.workingCopies[0].codeComplete(cursorLocation, requestor, this.wcOwner);
+	assertResults(
+			"clone[METHOD_REF]{clone(), Ljava.lang.Object;, ()Ljava.lang.Object;, clone, null, 60}\n" +
+			"equals[METHOD_REF]{equals(), Ljava.lang.Object;, (Ljava.lang.Object;)Z, equals, (obj), 60}\n" +
+			"f[FIELD_REF]{f, LFoo;, LFoo;, f, null, 60}\n" +
+			"finalize[METHOD_REF]{finalize(), Ljava.lang.Object;, ()V, finalize, null, 60}\n" +
+			"foo[METHOD_REF]{foo(), LFoo;, ()V, foo, null, 60}\n" +
+			"getClass[METHOD_REF]{getClass(), Ljava.lang.Object;, ()Ljava.lang.Class;, getClass, null, 60}\n" +
+			"hashCode[METHOD_REF]{hashCode(), Ljava.lang.Object;, ()I, hashCode, null, 60}\n" +
+			"notify[METHOD_REF]{notify(), Ljava.lang.Object;, ()V, notify, null, 60}\n" +
+			"notifyAll[METHOD_REF]{notifyAll(), Ljava.lang.Object;, ()V, notifyAll, null, 60}\n" +
+			"toString[METHOD_REF]{toString(), Ljava.lang.Object;, ()Ljava.lang.String;, toString, null, 60}\n" +
+			"wait[METHOD_REF]{wait(), Ljava.lang.Object;, ()V, wait, null, 60}\n" +
+			"wait[METHOD_REF]{wait(), Ljava.lang.Object;, (J)V, wait, (millis), 60}\n" +
+			"wait[METHOD_REF]{wait(), Ljava.lang.Object;, (JI)V, wait, (millis, nanos), 60}",
+			requestor.getResults());
+}
+public void testBug573632c() throws Exception {
+	// variation: while
+	this.workingCopies = new ICompilationUnit[1];
+	this.workingCopies[0] = getWorkingCopy(
+			"Completion/src/Foo.java",
+			"package test;\n" +
+			"public class Foo {\n" +
+			"	Foo f;\n" +
+			"	public void foo() {\n" +
+			"		while (f != null) {\n" +
+			"			f.\n" +
+			"			f = null;\n" +
+			"		}\n" +
+			"	};\n" +
+			"}\n");
+
+	CompletionTestsRequestor2 requestor = new CompletionTestsRequestor2(true);
+	requestor.allowAllRequiredProposals();
+	String str = this.workingCopies[0].getSource();
+	String completeBehind = "f.";
+	int cursorLocation = str.lastIndexOf(completeBehind) + completeBehind.length();
+	this.workingCopies[0].codeComplete(cursorLocation, requestor, this.wcOwner);
+	assertResults(
+			"clone[METHOD_REF]{clone(), Ljava.lang.Object;, ()Ljava.lang.Object;, clone, null, 60}\n" +
+			"equals[METHOD_REF]{equals(), Ljava.lang.Object;, (Ljava.lang.Object;)Z, equals, (obj), 60}\n" +
+			"f[FIELD_REF]{f, LFoo;, LFoo;, f, null, 60}\n" +
+			"finalize[METHOD_REF]{finalize(), Ljava.lang.Object;, ()V, finalize, null, 60}\n" +
+			"foo[METHOD_REF]{foo(), LFoo;, ()V, foo, null, 60}\n" +
+			"getClass[METHOD_REF]{getClass(), Ljava.lang.Object;, ()Ljava.lang.Class;, getClass, null, 60}\n" +
+			"hashCode[METHOD_REF]{hashCode(), Ljava.lang.Object;, ()I, hashCode, null, 60}\n" +
+			"notify[METHOD_REF]{notify(), Ljava.lang.Object;, ()V, notify, null, 60}\n" +
+			"notifyAll[METHOD_REF]{notifyAll(), Ljava.lang.Object;, ()V, notifyAll, null, 60}\n" +
+			"toString[METHOD_REF]{toString(), Ljava.lang.Object;, ()Ljava.lang.String;, toString, null, 60}\n" +
+			"wait[METHOD_REF]{wait(), Ljava.lang.Object;, ()V, wait, null, 60}\n" +
+			"wait[METHOD_REF]{wait(), Ljava.lang.Object;, (J)V, wait, (millis), 60}\n" +
+			"wait[METHOD_REF]{wait(), Ljava.lang.Object;, (JI)V, wait, (millis, nanos), 60}",
+			requestor.getResults());
+}
 }
diff --git a/org.eclipse.jdt.core.tests.model/src/org/eclipse/jdt/core/tests/model/CompletionTests9.java b/org.eclipse.jdt.core.tests.model/src/org/eclipse/jdt/core/tests/model/CompletionTests9.java
index 6a9596b017..a9420b7ba8 100644
--- a/org.eclipse.jdt.core.tests.model/src/org/eclipse/jdt/core/tests/model/CompletionTests9.java
+++ b/org.eclipse.jdt.core.tests.model/src/org/eclipse/jdt/core/tests/model/CompletionTests9.java
@@ -1636,4 +1636,42 @@ public void testBug560606() throws CoreException {
 		deleteProject(project1);
 	}
 }
+public void testBug573632d() throws Exception {
+	IJavaProject project1 = createJavaProject("Completion9_1", new String[] {"src"}, new String[] {"JCL19_LIB", "org.eclipse.jdt.core.tests.model.TEST_CONTAINER"}, "bin", "9");
+	try {
+		project1.open(null);
+		CompletionResult result = complete(
+			"/Completion9_1/src/Foo.java",
+			"package test;\n" +
+			"import java.io.InputStream;\n" +
+			"public class Foo {\n" +
+			"	Foo f;\n" +
+			"	public void foo() {\n" +
+			"		InputStream is = new InputStream(null);\n" +
+			"		try (is) {\n" +
+			"			f.\n" +
+			"			f = null;\n" +
+			"		}\n" +
+			"	};\n" +
+			"}\n",
+			"f.");
+		assertResults(
+			"clone[METHOD_REF]{clone(), Ljava.lang.Object;, ()Ljava.lang.Object;, clone, null, 60}\n" +
+			"equals[METHOD_REF]{equals(), Ljava.lang.Object;, (Ljava.lang.Object;)Z, equals, (obj), 60}\n" +
+			"f[FIELD_REF]{f, LFoo;, LFoo;, f, null, 60}\n" +
+			"finalize[METHOD_REF]{finalize(), Ljava.lang.Object;, ()V, finalize, null, 60}\n" +
+			"foo[METHOD_REF]{foo(), LFoo;, ()V, foo, null, 60}\n" +
+			"getClass[METHOD_REF]{getClass(), Ljava.lang.Object;, ()Ljava.lang.Class<+Ljava.lang.Object;>;, getClass, null, 60}\n" +
+			"hashCode[METHOD_REF]{hashCode(), Ljava.lang.Object;, ()I, hashCode, null, 60}\n" +
+			"notify[METHOD_REF]{notify(), Ljava.lang.Object;, ()V, notify, null, 60}\n" +
+			"notifyAll[METHOD_REF]{notifyAll(), Ljava.lang.Object;, ()V, notifyAll, null, 60}\n" +
+			"toString[METHOD_REF]{toString(), Ljava.lang.Object;, ()Ljava.lang.String;, toString, null, 60}\n" +
+			"wait[METHOD_REF]{wait(), Ljava.lang.Object;, ()V, wait, null, 60}\n" +
+			"wait[METHOD_REF]{wait(), Ljava.lang.Object;, (J)V, wait, (millis), 60}\n" +
+			"wait[METHOD_REF]{wait(), Ljava.lang.Object;, (JI)V, wait, (millis, nanos), 60}",
+			result.proposals);
+	} finally {
+		deleteProject(project1);
+	}
+}
 }
\ No newline at end of file
diff --git a/org.eclipse.jdt.core/codeassist/org/eclipse/jdt/internal/codeassist/complete/CompletionParser.java b/org.eclipse.jdt.core/codeassist/org/eclipse/jdt/internal/codeassist/complete/CompletionParser.java
index de79ff84c0..ace2ddef20 100644
--- a/org.eclipse.jdt.core/codeassist/org/eclipse/jdt/internal/codeassist/complete/CompletionParser.java
+++ b/org.eclipse.jdt.core/codeassist/org/eclipse/jdt/internal/codeassist/complete/CompletionParser.java
@@ -4012,8 +4012,8 @@ protected void consumeSwitchLabeledBlock() {
 protected int fetchNextToken() throws InvalidInputException {
 	int token = this.scanner.getNextToken();
 	if (!this.diet && token != TerminalTokens.TokenNameEOF) {
-		if (!requireExtendedRecovery() && this.expressionPtr == -1) {
-			if (this.scanner.currentPosition > this.cursorLocation) {
+		if (!requireExtendedRecovery() && this.scanner.currentPosition > this.cursorLocation) {
+			if (!hasPendingExpression(token)) {
 				this.scanner.eofPosition = this.cursorLocation + 1; // revert to old strategy where we stop parsing right at the cursor
 
 				// stop immediately or deferred?
@@ -4028,6 +4028,26 @@ protected int fetchNextToken() throws InvalidInputException {
 	}
 	return token;
 }
+private boolean hasPendingExpression(int token) {
+	if (this.expressionPtr == -1)
+		return false;
+	if (token == TerminalTokens.TokenNameDOT) {
+		// at '.' we are more eager to send early EOF to avoid seeing a qualified type reference in this pattern:
+		//   foo.|
+		//   bar ...
+		Expression expression = this.expressionStack[this.expressionPtr];
+		int elPtr = this.elementPtr;
+		while (elPtr >= 0) {
+			if (this.elementKindStack[elPtr] == K_BLOCK_DELIMITER) {
+				if (this.elementObjectInfoStack[elPtr] == expression) {
+					return false; // top expr on expressionStack belongs to a block statement (e.g., an if-condition)
+				}
+			}
+			elPtr--;
+		}
+	}
+	return true;
+}
 @Override
 protected void consumeToken(int token) {
 	if(this.isFirst) {
@@ -4291,10 +4311,19 @@ protected void consumeToken(int token) {
 					if (kind == K_CONTROL_STATEMENT_DELIMITER) {
 						int info = topKnownElementInfo(COMPLETION_OR_ASSIST_PARSER);
 						popElement(K_CONTROL_STATEMENT_DELIMITER);
-						if (info == IF) {
-							pushOnElementStack(K_BLOCK_DELIMITER, IF, this.expressionStack[this.expressionPtr]);
-						} else {
-							pushOnElementStack(K_BLOCK_DELIMITER, info);
+						switch (info) {
+							case IF:
+								// include top-expression of these just for the benefit of hasPendingExpression():
+								// (TRY is not included, even Java9-t-w-r doesn't own an *expression*)
+							case FOR:
+							case WHILE:
+								if (this.expressionPtr > -1) {
+									pushOnElementStack(K_BLOCK_DELIMITER, info, this.expressionStack[this.expressionPtr]);
+									break;
+								}
+								//$FALL-THROUGH$
+							default:
+								pushOnElementStack(K_BLOCK_DELIMITER, info);
 						}
 					} else {
 						switch(previous) {