ld "undefined reference" shows wrong line number

ld "undefined reference" shows wrong line number

[Jon Grant]

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Hello

I noticed in a version of the tools I am using that the output from ld
shows the wrong line number for an "undefined reference". as my tools
are not so recent (codesourcery), would someone be able to confirm if
this issue is reproducable if possible please.

The line number 19 is the last symbol in the start.S. void main(void)
function does exist in the build as well. Possibly is this the debug
info that is incorrect in the start.o file?

I attach my sample assembler file, which is for ARM.

Let me know if you would like me to create a bugzilla ticket.

Best regards, Jon



./libtest.a(start.o): In function `go_main':
c:\test\start.S:19: undefined reference to `global_buffer'
collect2: ld returned 1 exit status
make: *** [test.elf] Error 1



C:\>arm-none-eabi-ld --version
GNU ld (Sourcery G++ Lite 2010.09-51) 2.20.51.20100809

arm-none-eabi-gcc (Sourcery G++ Lite 2010.09-51) 4.5.1

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.global entrypoint


entrypoint:
	LDR		PC,=test
	LDR		PC,=test
	LDR		PC,=test
	LDR		PC,=test
	LDR		PC,=test
	LDR		PC,=test

test:
	LDR		R1,=global_buffer


go_main:
	LDR		PC, =main
	NOP
	LDR		PC, =main

	.END

Re: ld "undefined reference" shows wrong line number

[Nick Clifton]

Hi Jon,

> would someone be able to confirm if
> this issue is reproducable if possible please.

Not with the information you provided.  In particular we need the 
command line to assemble the start.S file and the command line used to 
link it afterwards.

> The line number 19 is the last symbol in the start.S. void main(void)
> function does exist in the build as well. Possibly is this the debug
> info that is incorrect in the start.o file?

Very probably.

> Let me know if you would like me to create a bugzilla ticket.

Yes please.  Please include the start.S file as well as the command 
lines mentioned above.

Cheers
   Nick

ld "undefined reference" shows wrong line number

[Jon Grant]

Hi Nick

Thank you for your reply.

On 21 June 2011 16:13, Nick Clifton <nickc@redhat.com> wrote:
> Hi Jon,
>
>> would someone be able to confirm if
>> this issue is reproducable if possible please.
>
> Not with the information you provided.  In particular we need the command
> line to assemble the start.S file and the command line used to link it
> afterwards.

Sorry, I should have provided more info.

I have created a ticket:

http://sourceware.org/bugzilla/show_bug.cgi?id=12974

Cmd line:
arm-none-eabi-gcc -g start.S main.c  -o test.elf

^ Note the -g is necessary to see line numbers rather than assembler
hex refs in the outout. I expect you already knew this though!


>> The line number 19 is the last symbol in the start.S. void main(void)
>> function does exist in the build as well. Possibly is this the debug
>> info that is incorrect in the start.o file?
>
> Very probably.
>
>> Let me know if you would like me to create a bugzilla ticket.
>
> Yes please.  Please include the start.S file as well as the command lines
> mentioned above.

I've attached a zip to the bug ticket 12974 with the start.S and command line.

Thank you for taking a look.

Best regards, Jon