GDB Trace functions calls when executing a program

GDB Trace functions calls when executing a program

[Satya Prakash Prasad]

Please let me know if in GDB there is a way to print function names when
program is executing - this is to just track / trace the code flow.

Generally in projects which has thousands of lines of code - it is very
difficult to trace a flow. The first is to decide where to put a breakpoint
for analysis. But to know the place to put breakpoint we need to know where
to enable it - I mean it should be within a function of a flow.

So can we just enable some command and let the program when running using
gdb - gdb can simply print functions name as it executes them.

Is the same possible?

Regards,
Prakash

Re: GDB Trace functions calls when executing a program

[Yubin Ruan]

On Wed, Feb 28, 2018 at 08:49:17PM +0530, Satya Prakash Prasad wrote:
> Please let me know if in GDB there is a way to print function names when
> program is executing - this is to just track / trace the code flow.
> 
> Generally in projects which has thousands of lines of code - it is very
> difficult to trace a flow. The first is to decide where to put a breakpoint
> for analysis. But to know the place to put breakpoint we need to know where
> to enable it - I mean it should be within a function of a flow.
> 
> So can we just enable some command and let the program when running using
> gdb - gdb can simply print functions name as it executes them.
> 
> Is the same possible?

Do you have access to the source? If so, why not simply add a print at the
very beginning of every function call:

    print("function called: %s\n", __FUNC__);

I know that strace can be used to trace system calls, but not normal function
calls. Maybe try LTTng: https://lttng.org/

Yubin

Re: GDB Trace functions calls when executing a program

[Satya Prakash Prasad]

Thanks for the details - please note that I am using Win7 and MingW for our
project and the LTTng tools is only for *nix platform. Can you please let
me know similar tool for Windows.

Also inserting printf in each function call is not possible cause it would
take long hours and effort for a code spreading thousands of lines.

Regards,
Prakash

On Thu, Mar 8, 2018 at 7:14 AM, Yubin Ruan <ablacktshirt@gmail.com> wrote:

> On Wed, Feb 28, 2018 at 08:49:17PM +0530, Satya Prakash Prasad wrote:
> > Please let me know if in GDB there is a way to print function names when
> > program is executing - this is to just track / trace the code flow.
> >
> > Generally in projects which has thousands of lines of code - it is very
> > difficult to trace a flow. The first is to decide where to put a
> breakpoint
> > for analysis. But to know the place to put breakpoint we need to know
> where
> > to enable it - I mean it should be within a function of a flow.
> >
> > So can we just enable some command and let the program when running using
> > gdb - gdb can simply print functions name as it executes them.
> >
> > Is the same possible?
>
> Do you have access to the source? If so, why not simply add a print at the
> very beginning of every function call:
>
>     print("function called: %s\n", __FUNC__);
>
> I know that strace can be used to trace system calls, but not normal
> function
> calls. Maybe try LTTng: https://lttng.org/
>
> Yubin
>

Re: GDB Trace functions calls when executing a program

[Jonah Graham]

On 7 Mar 2018 06:17, "Satya Prakash Prasad" <satyaprakash.prasad@gmail.com>
wrote:


Also inserting printf in each function call is not possible cause it would
take long hours and effort for a code spreading thousands of lines.


You can let the compiler do the heavy lifting by using
-finstrument-functions

Here is a nice blog post about it
https://mcuoneclipse.com/2015/04/04/poor-mans-trace-free-of-charge-function-entryexit-trace-with-gnu-tools/