Bug 7051 - remove broken printf %n directive support
Summary: remove broken printf %n directive support
Status: RESOLVED FIXED
Alias: None
Product: systemtap
Classification: Unclassified
Component: runtime (show other bugs)
Version: unspecified
: P2 normal
Target Milestone: ---
Assignee: Unassigned
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2008-11-25 16:48 UTC by Frank Ch. Eigler
Modified: 2008-12-29 18:34 UTC (History)
1 user (show)

See Also:
Host:
Target:
Build:
Last reconfirmed: 2008-12-02 18:03:43

Attachments
Add an attachment (proposed patch, testcase, etc.)

Note You need to log in before you can comment on or make changes to this bug.
Description Frank Ch. Eigler 2008-11-25 16:48:29 UTC 
ksebasti found several issues with this widget:

printf ("%n%4d", 0) prints 0x04 0x00 0x00 0x00 0x00
printf ("%n%n%n") prints junk
printf ("%n") prints junk

If we keep %n around at all, it needs to compose sensibly.
We could make it mean "total record length", so that the
previous three cases would print

printf ("%n%4d", 0) would print 0x05 0x00 0x00 0x00 0x00
printf ("%n%n%n") would print 0x03 0x03 0x03
printf ("%n") would print 0x01
Comment 1 Prerna 2008-12-02 09:41:19 UTC 
I'm not too sure if %n is useful enough to be retained..
Comment 2 Prerna 2008-12-02 09:45:58 UTC 
Waiting for feedback on whether %n directive should be continued with...
Comment 3 Frank Ch. Eigler 2008-12-02 18:03:43 UTC 
If there is no dissent, let's get rid of it.
Comment 4 Kent Sebastian 2008-12-05 19:09:13 UTC 
removed as of commit 89b011d52e247d9a3933b5d37af72de4d44212bd
Comment 5 K.Prasad 2008-12-29 18:34:06 UTC 
Table-1 in langreg.pdf needs to be corrected to indicate the absence of %n 
printf specifier.