Bug 93208

Summary:

[dom] CompilationUnit.rewrite throws AssertionFailedException with legal AST (bug in recoding ast modifications)

Product:

[Eclipse Project] JDT

Reporter:

Rodrigo Kumpera <kumpera>

Component:

Core

Assignee:

David Audel <david_audel>

Status:

CLOSED FIXED

QA Contact:

Severity:

normal

Priority:

Version:

3.0.2

Target Milestone:

3.1 RC2

Hardware:

OS:

Windows NT

Whiteboard:

Attachments:

Description	Flags
JUnit testcase for the bug	none

Description Rodrigo Kumpera

2005-04-28 21:25:41 EDT

While recording AST modifications and copySubtree is performed on a node from 
the same AST, eg: ASTNode x = ast.newXXX ... y = ASTNode.copySubtree(ast, x), 
when the edit is requested it fails to get the source from the original node 
with an Assertion exception.

I'm not sure if it's my fault, but ASTNode.copySubtree javadoc implies that 
this is a legal operation.

I get the following stack trace when running the attached unit test (irrelevant 
traces removed):

org.eclipse.jface.text.Assert$AssertionFailedException: Assertion failed: 
	at org.eclipse.jface.text.Assert.isTrue(Assert.java:177)
	at org.eclipse.jface.text.Assert.isTrue(Assert.java:162)
	at org.eclipse.text.edits.TextEdit.<init>(TextEdit.java:149)
	at org.eclipse.text.edits.CopySourceEdit.<init>(CopySourceEdit.java:96)
	at 
org.eclipse.jdt.internal.core.dom.rewrite.ASTRewriteAnalyzer.getCopySourceEdit
(ASTRewriteAnalyzer.java:128)
	at 
org.eclipse.jdt.internal.core.dom.rewrite.ASTRewriteAnalyzer.doTextInsert
(ASTRewriteAnalyzer.java:984)
	at 
org.eclipse.jdt.internal.core.dom.rewrite.ASTRewriteAnalyzer$ListRewriter.rewrit
eList(ASTRewriteAnalyzer.java:461)
	at 
org.eclipse.jdt.internal.core.dom.rewrite.ASTRewriteAnalyzer.rewriteParagraphLis
t(ASTRewriteAnalyzer.java:837)
	at org.eclipse.jdt.internal.core.dom.rewrite.ASTRewriteAnalyzer.visit
(ASTRewriteAnalyzer.java:1263)
	at org.eclipse.jdt.core.dom.TypeDeclaration.accept0
(TypeDeclaration.java:469)
	at org.eclipse.jdt.core.dom.ASTNode.accept(ASTNode.java:2450)
	at org.eclipse.jdt.internal.core.dom.rewrite.ASTRewriteAnalyzer.doVisit
(ASTRewriteAnalyzer.java:249)
	at 
org.eclipse.jdt.internal.core.dom.rewrite.ASTRewriteAnalyzer.doVisitList
(ASTRewriteAnalyzer.java:280)
	at 
org.eclipse.jdt.internal.core.dom.rewrite.ASTRewriteAnalyzer.doVisitUnchangedChi
ldren(ASTRewriteAnalyzer.java:298)
	at org.eclipse.jdt.internal.core.dom.rewrite.ASTRewriteAnalyzer.visit
(ASTRewriteAnalyzer.java:1151)
	at org.eclipse.jdt.core.dom.CompilationUnit.accept0
(CompilationUnit.java:287)
	at org.eclipse.jdt.core.dom.ASTNode.accept(ASTNode.java:2450)
	at org.eclipse.jdt.core.dom.InternalASTRewrite.rewriteAST
(InternalASTRewrite.java:71)
	at org.eclipse.jdt.core.dom.AST.rewrite(AST.java:2642)
	at org.eclipse.jdt.core.dom.CompilationUnit.rewrite
(CompilationUnit.java:853)
	at jdt.tests.AstRewriteBug.testAstRewriteBug(AstRewriteBug.java:60)

Comment 1 Rodrigo Kumpera

2005-04-28 21:27:33 EDT

Created attachment 20487 [details]
JUnit testcase for the bug

Comment 2 Rodrigo Kumpera

2005-05-02 15:46:46 EDT

I've found a workaround for this bug. Instead of copying the subtree, make the 
node orfan and use it. This might even save some bits of memory since 
copySubTree does not perform COW.

This method does the kludge:

    public static void killParent(ASTNode node) {
        StructuralPropertyDescriptor locationInParent = node
                .getLocationInParent();
        if (!locationInParent.isChildListProperty())
            node.getParent().setStructuralProperty(locationInParent, node.getAST
().newNullLiteral());
        else {
            List list = (List) node.getParent().getStructuralProperty(
                    locationInParent);
            list.remove(node);
        }
    }

Comment 3 Olivier Thomann

2005-06-07 11:08:49 EDT

Martin, could you please check if this occurs in HEAD?

Comment 4 Martin Aeschlimann

2005-06-07 11:28:33 EDT

Bug is in the modifying ast rewrite: A close on a new (non-original) node should
not create a copy event. New end original nodes can be distinguised with the
'ASTNode.ORIGINAL' flag.

Moving to Daniel

Comment 5 Philipe Mulet

2005-06-09 09:54:52 EDT

+1 for RC2

Comment 6 David Audel

2005-06-09 09:59:27 EDT

Fixed and test added
  ASTRewritingModifyingCopyTest#test0007()

Replaced

void postCloneNodeEvent(ASTNode node, ASTNode clone) {
	this.clonedNodes.put(clone, node);
	this.cloneDepth--;
}

by

void postCloneNodeEvent(ASTNode node, ASTNode clone) {
	if(node.ast == root.ast && clone.ast == root.ast) {
		if((node.getFlags() & ASTNode.ORIGINAL) != 0) {
			this.clonedNodes.put(clone, node);
		} else {
			// node can be a cloned node
			Object original = this.clonedNodes.get(node);
			if(original != null) {
				this.clonedNodes.put(clone, original);
			}
		}
	}
	this.cloneDepth--;
}

Comment 7 Olivier Thomann

2005-06-09 10:51:27 EDT

Verified in N20050609-0010 + JDT/Core HEAD.

Verified that the attached Junit test passed.
Result in System.out is:
package test; public class Test {

	void foo(){this.x;} }

Comment 8 Olivier Thomann

2005-06-10 12:10:48 EDT

Verified in I20050610-0010.