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Re: [PATCH] testsuite/gdb.dwarf2: Fix for dw2-ifort-parameter failure on ARM



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


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