Bug 83971 - gcc -static link command hardcoded when --with-system-libunwind used
Summary: gcc -static link command hardcoded when --with-system-libunwind used
Status: UNCONFIRMED
Alias: None
Product: gcc
Classification: Unclassified
Component: driver (show other bugs)
Version: unknown
: P3 normal
Target Milestone: ---
Assignee: Not yet assigned to anyone
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2018-01-22 15:21 UTC by Jason Duerstock
Modified: 2018-01-22 16:15 UTC (History)
0 users

See Also:
Host:
Target:
Build:
Known to work:
Known to fail:
Last reconfirmed:

Attachments
example build log (299 bytes, text/plain)
2018-01-22 15:21 UTC, Jason Duerstock 		Details
View All 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 Jason Duerstock 2018-01-22 15:21:21 UTC 
Created attachment 43207 [details]
example build log

Modern versions of libunwind include liblzma for decompressing compressed symbol tables.  So when gcc is built with --with-system-libunwind, static links will fail because gcc is hardcoded to use "-lunwind" rather than the results of "pkg-config --libs --static libunwind".  As a result, liblzma.a is not included when it should be.

See https://buildd.debian.org/status/fetch.php?pkg=libdebug&arch=ia64&ver=0.5.2-2&stamp=1516055815&raw=0 for a full build log.

The problem seems to stem from gcc/gcc.c:init_spec()
Comment 1 Andrew Pinski 2018-01-22 15:28:37 UTC 
Usually --with-system-libunwind is only used on ia64 and no other target.
Comment 2 Jason Duerstock 2018-01-22 16:15:12 UTC 
At least tangentially related, what's the reason only ia64 needs libunwind?  What happens if gcc is built with --disable-libunwind-exceptions?  I haven't been able to find a clear explanation regarding this anywhere.