GCC 12.2 changes

[drgrandios]

Hi,

I tried to make your code run using GCC 12.2 (RISCV target).

It seems that the GCC people changed the internal gcov_info struct - between stamp and filename there is a new additional checksum field.

See here: https://github.com/gcc-mirror/gcc/blob/4d1e4ce986f84a853531ac9c51e37d101e28d15c/libgcc/libgcov.h#L232

After adding the checksum field, the lib worked also using the newer GCC.

[drgrandios]

... unfortunately have to add that it now builds fine and spits out results, but the result evaluation ends up in zero line coverage all the time. Need to investigate a bit more....

[drgrandios]

Besides having an additional checksum field in the gcov_info struct, the .gcda files also have this checksum added to their header, see this line:

https://github.com/gcc-mirror/gcc/blob/4d1e4ce986f84a853531ac9c51e37d101e28d15c/libgcc/libgcov-driver.c#LL519C50-L519C50

[drgrandios]

Okay, eventually found the third difference:

The definition of GCOV_TAG_FUNCTION_LENGTH and GCOV_TAG_COUNTER_LENGTH has changed from words to bytes, see here:

https://github.com/gcc-mirror/gcc/blob/4d1e4ce986f84a853531ac9c51e37d101e28d15c/gcc/gcov-io.h#L258

After correction of these values, gcov & lcov could successfully create a valid coverage report.

Summary:

• add checksum field to gcov_info
• write checksum field after stamp when generating gcda header
• correct sizes of GCOV_TAG_FUNCTION_LENGTH and GCOV_TAG_COUNTER_LENGTH

Not sure if this of interest for @KenPetersJPL ?

[GigAnon]

With the modifications pointed out by @drgrandios I managed to make a cross-target GCOV work with GCC14. Given that GCC14 adds actual MC/DC coverage out of the box, this is a high-value ticket.

[Bresenham]

@drgrandios You are the boss!

@GigAnon I am getting this error:

$ lcov --capture --initial --directory . -o coverage.info
Capturing coverage data from .
Found gcov version: 10.2.1
Using intermediate gcov format
Scanning . for .gcno files ...
Found 4 graph files in .
Processing gcov_public.c.gcno
/home/user/obj/gcov_public.c.gcno:version 'B22*', prefer 'B02*'
geninfo: ERROR: GCOV failed for /home/user/obj/gcov_public.c.gcno:version!

Does anyone know how to resolve this? I read in https://github.com/nasa-jpl/embedded-gcov/blob/main/scripts/lcov_baseline.sh that the gcov tool has to be compiled with gcc arm none eabi (in my case as I have a Cortex M7). Did you really have to do this? Where do I get the source of gcov?

Edit: Okay, I had to install the latest lcov (version 2.1) from here: https://github.com/linux-test-project/lcov/releases and then supply the property --gcov-tool to use bin/arm-none-eabi-gcov. Then I used lcov-2.1/bin/genhtml and everything worked fine!