Bug 71530

Summary:	[Scanner] CModel Line Numbers are incorrect w/Scanner2
Product:	[Tools] CDT	Reporter:	John Camelon <john.camelon>
Component:	cdt-parser	Assignee:	John Camelon <john.camelon>
Status:	RESOLVED FIXED	QA Contact:
Severity:	major
Priority:	P2	CC:	aniefer, dave.daoust
Version:	2.0
Target Milestone:	2.0.1
Hardware:	PC
OS:	Windows XP
Whiteboard:

Description John Camelon

2004-08-05 18:11:38 EDT

I'm raising this defect as a placeholder for the regression that our new 
Scanner migration has created.  

Both our CModelElementsTest (Quick & Structural) have the body of 
checkLineNumbers() commented out.  These tests fail regularily.

Comment 1 John Camelon

2004-08-16 15:34:30 EDT

I haven't committed this fix yet, as it negatively affects performance.  

Attempt 1 (where we keep track of \n's throughout the scanner) yielded 
incorrect results.  

Attempt 2 (where we figure it out as we go without storing information) hurt 
our performance by an order of magnitude ... ~41 seconds to parse the trilogy. 

Attempt 3 (where we store some meta-data to help us take shortcuts in figuring 
out line numbers) yield 30% degradation over what is currently in 2.0.1 
branch/HEAD.  

I'll keep plowing away at this with further optimizations.  
Since we do not need line numbers for content assist, I plan to short-circuit 
this code in COMPLETION_PARSE mode.  The same can go for handleProblem() since 
Content Assist cares not for IProblem.

Comment 2 John Camelon

2004-08-16 15:58:01 EDT

I've managed to find a solution which adds only a couple of milliseconds 
overhead to parsing the trilogy.  

Fix applied to HEAD and 2_0 branch.