[Bug gcov-profile/114751] New: .gcda:stamp mismatch with notes file

[Bug gcov-profile/114751] New: .gcda:stamp mismatch with notes file

[gejoed at rediffmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114751

            Bug ID: 114751
           Summary: .gcda:stamp mismatch with notes file
           Product: gcc
           Version: 11.4.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: gcov-profile
          Assignee: unassigned at gcc dot gnu.org
          Reporter: gejoed at rediffmail dot com
  Target Milestone: ---

Hi team,

In my org project we use gcc/gcov which is customised by another team. However
with version 11.4.0 we did see a '.gcda:stamp mismatch with notes file' while
running gcov tool. The same command goes fine with the previous branch code
which uses gcc 10.3.0. 

Example would be like :
<toolchain-path>/gcov -l src-file.c -o ./src-file-obj-dir-path

src-file.gcda:stamp mismatch with notes file
File 'src-file.c'
Lines executed:0.00% of 36
Creating 'src-file.c.gcov'

File '../../abcd/ef/hijk.h'
Lines executed:0.00% of 2
Creating 'src-file.c##hijk.h.gcov'

File '../include/lmno.h'
Lines executed:0.00% of 2
Creating 'src-file.c##lmno.h.gcov'

Lines executed:0.00% of 40

This is seen for several files in the new branch of code where gcc v11.4.0 is
used and not seen with older branch where the gcc version is 10.3.0.

We generate the gcov based image (compiled with --coverage in CFLAGS) , load
the image on the device, do testing, collect gcda files from device and put it
back in the same obj-dir location and run the gcov tool to get the gcov files
(eg :src-file.c.gcov).

We checked the time stamp of gcda vs gcno files and even then the issue was
seen. Was there any specific enhancement with 11.x version which would be
causing the issue or is there any further check to be done during the
compilation with --coverage or during the gcov tool run ?

Due to my organisation restriction, I'm not able to give more info on the file
names used and the make file info but I can try the best to get the info for
your understanding. 
Awaiting valuable reply. 

Thank you team for your support always !

[Bug gcov-profile/114751] .gcda:stamp mismatch with notes file

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114751

--- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> ---
From reading what the gcov code does it somehow means that the gcda and gcno
files were not created consistently.

You can use gcov-dump to check the stamp, for an example pair I have around
I see consistent stamps:

> gcov-dump-13 t.gcda 
t.gcda:data:magic `gcda':version `B32*'
t.gcda:stamp 3774884159
t.gcda:checksum 2538568055
...

> gcov-dump-13 t.gcno
t.gcno:note:magic `gcno':version `B32*'
t.gcno:stamp 3774884159
t.gcno:checksum 0
...

[Bug gcov-profile/114751] .gcda:stamp mismatch with notes file

[gejoed at rediffmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114751

--- Comment #2 from Gejoe <gejoed at rediffmail dot com> ---

For me, it is like this (just keeping the sample filenames as such but the
values are real ones shown while checking with gcov-dump) :

$gcov-dump ./obj-dir-path/src-file.gcda
./obj-dir-path/src-file.gcda:data:magic `gcda':version `B14*'
./obj-dir-path/src-file.gcda:stamp 2912455990
:
<the rest truncated>

$ gcov-dump ./obj-dir-path/src-file.gcno
./obj-dir-path/src-file.gcno:note:magic `gcno':version `B14*'
./obj-dir-path/src-file.gcno:stamp 2912494680
:
<the rest truncated>

Does this indicate something more to be checked ?

In the previous branch where gcc 10.3.0 is used, I could see same stamp value
for the gcov-dump of same gcda and gcno files there - 3176078538.

Awaiting reply.

Thanks.

[Bug gcov-profile/114751] .gcda:stamp mismatch with notes file

[gejoed at rediffmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114751

--- Comment #3 from Gejoe <gejoed at rediffmail dot com> ---
Can I get a reply on what needs to be checked next ?

Thank you for the support team !

[Bug gcov-profile/114751] .gcda:stamp mismatch with notes file

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114751

--- Comment #4 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
*** Bug 114820 has been marked as a duplicate of this bug. ***

[Bug gcov-profile/114751] .gcda:stamp mismatch with notes file

[gejoed at rediffmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114751

--- Comment #5 from Gejoe <gejoed at rediffmail dot com> ---
(In reply to Gejoe from comment #2)
> For me, it is like this (just keeping the sample filenames as such but the
> values are real ones shown while checking with gcov-dump) :
> 
> $gcov-dump ./obj-dir-path/src-file.gcda
> ./obj-dir-path/src-file.gcda:data:magic `gcda':version `B14*'
> ./obj-dir-path/src-file.gcda:stamp 2912455990
> :
> <the rest truncated>
> 
> $ gcov-dump ./obj-dir-path/src-file.gcno
> ./obj-dir-path/src-file.gcno:note:magic `gcno':version `B14*'
> ./obj-dir-path/src-file.gcno:stamp 2912494680
> :
> <the rest truncated>
> 
> Does this indicate something more to be checked ?
> 
> In the previous branch where gcc 10.3.0 is used, I could see same stamp
> value for the gcov-dump of same gcda and gcno files there - 3176078538.
> 
> Awaiting reply.
> 
> Thanks.

Hi team,
Can I expect any reply on my message posted above ?

Thanks,
Gejoe

[Bug gcov-profile/114751] .gcda:stamp mismatch with notes file

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114751

--- Comment #6 from Richard Biener <rguenth at gcc dot gnu.org> ---
I have no idea why the values differ but I suspect the copying since we seem to
use the file modification time at some point.  As a workaround I would suggest
to binary-patch one of the file to make the stamp match the other ...

[Bug gcov-profile/114751] .gcda:stamp mismatch with notes file

[gejoed at rediffmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114751

--- Comment #7 from Gejoe <gejoed at rediffmail dot com> ---
(In reply to Richard Biener from comment #6)
> I have no idea why the values differ but I suspect the copying since we seem
> to use the file modification time at some point.  As a workaround I would
> suggest
> to binary-patch one of the file to make the stamp match the other ...

We do use __gcov_dump() in the program execution to get all the gcda files, tar
them up to a file name and we move that to the workspace where build was done
we use a script to run gcov so that gcov files are created finally. So, will
there be any changes in GCC 11.x (compared to 10.3.0) where __gcov_dump and the
ensuing copy process need to be taken care in a better way ? 

I'm not sure of the binary-patching of the file mentioned above. Can you 
elaborate that suggestion ? 

Thank you for bearing with my queries patiently and for the possible help
given.

[Bug gcov-profile/114751] .gcda:stamp mismatch with notes file

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114751

--- Comment #8 from Richard Biener <rguenth at gcc dot gnu.org> ---
I don't know of any difference compared to older compilers but gcov isn't my
main expertise.  I fear you have to dig into the gcov code to see where and how
we exactly invent the stamp to see where it goes wrong for you.

It might be possible to ask on the gcc-help@ mailinglist as well as that might
receive a wider audience than bugzilla.