Callgraph

Hi Xol,

You can use arm-none-eabi-readlef -a on the library. You will have several blocks, one for each file in the library. This will already allow you to narrow down to a particular file. Then the entries with the name of interest (eg. _getpid) will have an offset that indicates where is the undefined reference in the object file. You can then just use arm-none-eabi-objdump -d to find what function is at this address.

Best regards.

I meant arm-none-eabi-readelf

Hi,
Thanks for help but this is still not complete.
Inside my library there are no direct calls to _getpid. More likely _getpid is called from one of the standard C libraries. So readelf provides no references to _getpid if I run it on my library file.

Is where any way to build and link my library together with standard C library so that all library calls to stdlib functions would be already linked into library file. In this case I hope to see calls to _getpid.

My other option is to make the whole project and provide some dummy file with body of _getpid to make linker satisfied and let him generate ELF file. After that run readelf and catch the references to my dummy _getpid.

What do you think?

OK, I did what I sad and finally had found out that undefined references are coming from unwind functions. Adding -fno-unwind-tables elliminate that references. If you can please explain me what is the unwind-tables functionality?

But now I face another problem:

c:/arm_gcc/5.2_2015q4/bin/../lib/gcc/arm-none-eabi/5.2.1/../../../../arm-none-eabi/bin/ld.exe: section .ARM.exidx loaded at [08073010,08073017] overlaps section .data loaded at [08073010,08073643]

Can you please tell me what is the .ARM.exidx section and how to get rid of it. Temporary I have changed my linker script to discard this section.

Thanks.

I have posted a number of comments and quest. Will they be addressed? Thanks.

Sent from my Brain

> On Oct 29, 2016, at 08:13, xol <email address hidden> wrote:
>
> Your question #403575 on GNU ARM Embedded Toolchain changed:
> https://answers.launchpad.net/gcc-arm-embedded/+question/403575
>
> Status: Answered => Open
>
> You are still having a problem:
> Hi,
> Thanks for help but this is still not complete.
> Inside my library there are no direct calls to _getpid. More likely _getpid is called from one of the standard C libraries. So readelf provides no references to _getpid if I run it on my library file.
>
> Is where any way to build and link my library together with standard C
> library so that all library calls to stdlib functions would be already
> linked into library file. In this case I hope to see calls to _getpid.
>
> My other option is to make the whole project and provide some dummy file
> with body of _getpid to make linker satisfied and let him generate ELF
> file. After that run readelf and catch the references to my dummy
> _getpid.
>
> What do you think?
>
> --
> You received this question notification because you asked the question.

Hi Xol,

-fno-unwind-tables affects program that use exceptions so if you are building a C application or if you are building a C++ application that does not use any exception disabling unwind-tables should be safe. .ARM.exidx is related to exceptions as well: The ELF for the ARM architecture document says it contains index entries for section unwinding. Again, if you are not using exception discarding it should be safe.

Best regards.