0005282: ExceptDlg does not work if app is compiled with package vcl and bounds-checking on (with solution) - Project JEDI

Project JEDI - Issue Tracker

Viewing Issue Simple Details [ Jump to Notes ]

[ View Advanced ] [ Issue History ] [ Print ]

Category

Severity

Reproducibility

Date Submitted

Last Update

0005282

[Code Library] JclDebug*

minor

always

2010-07-21 09:07

2010-09-02 16:33

Reporter

SurFan

View Status

public

Assigned To

outchy

Priority

normal

Resolution

fixed

Status

resolved

Product Version

Version 2.2

Summary

0005282: ExceptDlg does not work if app is compiled with package vcl and bounds-checking on (with solution)

Description

During the display of the exception Dialog stack trace, you'll get various errors depending on the project you use. Sometimes "Out of Memory" exception is thrown, often a "ListIndex out of bounds (2)"

Additional Information

Steps to reproduce:
- Create a one-line project that simply throws an exception
- Put exceptdlg in the uses of the project
- verify that vcl60.map is in the same directory as vcl60.bpl
- compile with runtimepackages (at least with vcl) and bounds-checking on

cause of the problem:
The statement in line 1419ff of Jcldebug: "Result := Result * 16" throws an Integer Overflow error (compiler bug?), if the result*16 is bigger than $7FFFFFFF.
Sadly the procedure "TLSLast" in vcl starts at offset "BFF36010" thus an error is thrown.
Now JclDebug intercepts and the recursion is perfect! The list index out of bounds comes from line 4832 of jcldebug, because while processing the IntegerOverflow exception, the original stacklist gets freed in line 4294, because it has the same Id and classname as the one that's been newly created by the IntegerOverflow exception, thus leading to use a freed object in TJclStackInfoList.addstrings (the "i" is now undefined!)

Solution:
replace "result := result * 16" by "result := result shl 4", and everything works as expected

Consideration:
Recursion in exception handling in Jcldebug should be taken care of by the JclDebug-Code

Tags

No tags attached.

Fixed in revision

3307

IDE version

Delphi 6

Attached Files

Relationships

Notes
(0017570) outchy (administrator) 2010-08-12 14:13	I applied a different patch in revision 3225. http://jcl.svn.sf.net/viewvc/jcl/trunk/jcl/source/windows/JclDebug.pas?r1=3224&r2=3225 [^] Basically, the result of ReadHexValue should be unsigned. However, I'll change the code to use "shl 4 or something", this is much better than "* 16 + something". Committed in revision 3307.

Issue History
Date Modified	Username	Field	Change
2010-07-21 09:07	SurFan	New Issue
2010-07-21 09:07	SurFan	IDE version	=> Delphi 6
2010-08-12 14:13	outchy	Note Added: 0017570
2010-08-12 14:13	outchy	Assigned To	=> outchy
2010-08-12 14:13	outchy	Status	new => feedback
2010-09-02 16:33	outchy	Fixed in revision	=> 3307
2010-09-02 16:33	outchy	Status	feedback => resolved
2010-09-02 16:33	outchy	Fixed in Version	=> Version 2.2
2010-09-02 16:33	outchy	Resolution	open => fixed

Mantis 1.1.6[^]