This is the mail archive of the
gdb-patches@sourceware.org
mailing list for the GDB project.
Re: [PATCH] testsuite/gdb.dwarf2: Fix for dw2-ifort-parameter failure on ARM
- From: Omair Javaid <omair dot javaid at linaro dot org>
- To: Pedro Alves <palves at redhat dot com>
- Cc: Yao Qi <yao at codesourcery dot com>, gdb-patches at sourceware dot org
- Date: Thu, 16 Jan 2014 15:26:13 +0500
- Subject: Re: [PATCH] testsuite/gdb.dwarf2: Fix for dw2-ifort-parameter failure on ARM
- Authentication-results: sourceware.org; auth=none
- References: <CANW4E-2bQYjx6YdR3qGyKUsQa_KOrtmkWsZYqKzcuQBF==RPpw at mail dot gmail dot com> <CANW4E-25HdXYKMk258iO=GZ=PNM=Zu4jMbstpkSoMgE9wFpmkQ at mail dot gmail dot com> <51E4B587 dot 70007 at codesourcery dot com> <CANW4E-0vd51dTvd5qxUbeDn7ebXV-cf+WS4+VpyyGyD0MYGk8Q at mail dot gmail dot com> <5280A528 dot 8040308 at codesourcery dot com> <52D7A05F dot 6070304 at linaro dot org> <52D7AAF1 dot 80501 at redhat dot com>
On 01/16/2014 02:48 PM, Pedro Alves wrote:
> On 01/16/2014 09:03 AM, Omair Javaid wrote:
>
>> There seemed no problem with how breakpoint addresses were being adjusted.
>> This test requires to build dwarf info by hand in dw2-ifort-parameter-debug.S
>> using compile time addresses so in case of arm (thumb mode) the least
>> significant bits of compile time address are set to 1. For that reason
>> 0x000083bd was being used as a breakpoint address func.
>
> OOC, what does the compiler debug info usually do instead to avoid this?
>
Here is what compiler generates when there are thumb functions to handle:
.thumb_func
.type func, %function
func:
.LFB0:
func is marked as thumb function and thus this func pointer will have the
lower bit set. While .LFB0: non thumb label will be used to mark function
start address. Like this: .4byte .LFB0 @ DW_AT_low_pc