Bug 22456

Summary: Bison versions under 2.2 produce crashing CSSGrammar code for ARM
Product: WebKit Reporter: Kalle Vahlman <zuh>
Component: WebKitGTKAssignee: Nobody <webkit-unassigned>
Status: RESOLVED FIXED    
Severity: Normal    
Priority: P2    
Version: 528+ (Nightly build)   
Hardware: PC   
OS: Linux   
Attachments:
Description Flags
Backtrace of the crash
none
Differences in generated code
none
And finally, a patch to check for bison version >=2.2 when compiling for ARM darin: review+

Kalle Vahlman
Reported 2008-11-24 07:08:12 PST
After agonizing bug hunting week, I found out that bison versions earlier than 2.2 produce faulty code that crashes on ARM CPUs from CSSGrammar.y. There's a similar issue reported as bug 18538 but that's probably not exactly the same thing as here. git-bisecting pointed http://trac.webkit.org/changeset/35351 as the revision that introduces the crashing. As I have no mad bison skillz, determining if the actual cause is a bison bug or something CSSGrammar.y could fix is a bit hard. But at the very least we could add a check to configure.ac for this and error out.
Attachments
Backtrace of the crash (3.63 KB, text/plain)
2008-11-24 07:09 PST, Kalle Vahlman 		no flags
Details
Differences in generated code (116.68 KB, text/x-patch)
2008-11-24 07:12 PST, Kalle Vahlman 		no flags
Details
And finally, a patch to check for bison version >=2.2 when compiling for ARM (1.50 KB, patch)
2008-11-24 07:17 PST, Kalle Vahlman 		darin: review+
DetailsFormatted DiffDiff
View All Add attachment proposed patch, testcase, etc.
Kalle Vahlman
Comment 1 2008-11-24 07:09:56 PST
Created attachment 25427 [details] Backtrace of the crash
Kalle Vahlman
Comment 2 2008-11-24 07:12:10 PST
Created attachment 25428 [details] Differences in generated code This diff shows the changes between a non-working (bison v1.875d) and working (bison v2.3) generated code (in case someone wants to get to the bottom of this...).
Kalle Vahlman
Comment 3 2008-11-24 07:17:54 PST
Created attachment 25429 [details] And finally, a patch to check for bison version >=2.2 when compiling for ARM
Darin Adler
Comment 4 2008-11-24 09:07:13 PST
Comment on attachment 25429 [details] And finally, a patch to check for bison version >=2.2 when compiling for ARM r=me
Jan Alonzo
Comment 5 2008-11-26 03:33:15 PST
Landed in r38782. Thanks!
Note You need to log in before you can comment on or make changes to this bug.