Lcov giving error with--gcov-tool 402; prefer A94 error

[Shyamlalkumawat]

While running the script with Gcov and lcov it is giving error for version '402', prefer 'A94' I have installed Gcov 9.4.0 and same gcc also

`` lcov --directory . --base-directory . --gcov-tool /usr/bin/gcov --capture -o cov.info Capturing coverage data from . Found gcov version: 9.4.0 Using intermediate gcov format Scanning . for .gcda files ... Found 1 data files in . Processing test1.gcda /home/android/Downloads/User/Test/test1.gcno:version '402', prefer 'A94' geninfo: ERROR: GCOV failed for /home/android/Downloads/Geeta/Test/test1.gcda!

I tried with --gcov-tool /usr/bin/gcov-9.4.0 also but same error. ``

Cov.info is also not generating

[henry2cox]

I do not have ready access to gcc/9.4 - so can't reproduce your experiment - however, gcov appears to be complaining that the data format is from gcc/4.X - not 9.X

What toolchain version did you use to compile and link your code? Platform probably doesn't matter...but what platform and version?

You could also try using gcov from a 4.8.X gcc toolchain.

It also appears that you truncated your output a bit - as there ought to be a bit more information in the error logs.

[Shyamlalkumawat]

I am having ubantu Linux system . And I have Android binary . And using this script https://gist.github.com/pankajgangwar/f070b8b54e83543f8e3638dcd2cae1b8

I am able to create .gcda and .gcno file . I have install gcc version - 9.4 which is latest. And same gcov version.

I am not able to install gcov 4.6 or 4.x as its deprecated and not available on ubantu repo.

Note- In the script gcc4.2 mentioned please consider gcc 9.4 or upper version. Should I install lower gcc version to wrok with it ?

Or something else issue If it is issue with data format of 9.X the. How to make compatible with 4.x pls guide

[henry2cox]

when we look at that script we discover:

• yeah - it uses llvm and llvm-cov
• it specifies to use gcov-4.6 - which is not entirely unexpected, as we know that llvm-cov produces data in gcov/4.X format.

If you really want to use gcc/9.4, I suggest a simple experiment to start you out:

1. write a tiny hello_world.c program
2. compile and link with gcc --coverage ....
3. run
4. extract lcov data via lcov --capture ... and see if you get compatabilty messages or valid data.

If the simple experiment works as expected and your android application does not...then we have quite a bit of confidence that your data was not generated with gcc/9.4.

If you do want to use llvm, then you could use llvm-profdata and llvm-cov export -format=lcov .... to produce your LCOV-format data - and bypass gcc entirely. Note that 'llvm-cov export ...' does not appear to support branch coverage (which is strange, as the profiles obviously contain the information); this is one reason why you might prefer the gcc approach.

[henry2cox]

The other thing I forgot to mention is that you can also simply use llvm-cov gcov ... to read the llvm-generated gcda/gcno files. llvm produced the data, and llvm is likely to be happy to read it. To to that: lcov --capture -o cov.info --gcov-tool llvm-cov --gcov-tool gcov -d myDir ...

(please see the lcov and/or geninfo man page for a more detailed description.

[henry2cox]

No followup - so I guess that this issue is addressed/you found matching tool versions and the error messages went away. If so: please go ahead and close this issue. If not: please describe the problems you see. Thanks Henry

[Shyamlalkumawat]

We are able to run the experiment but android binaray still having same error /home/android/code/manifest/out/coverage/USER/CPUDataProcessor.gcda:version '402', prefer version 'A94'

We have tried the llvm cov also but here some gcda file are not found.

lcov --directory . --gcov-tool /home/android/code/manifest/prebuilts/clang/host/linux-x86/llvm-binutils-stable/llvm-cov --capture -o covin.info --no-external Capturing coverage data from . Found LLVM gcov version 11.0.1, which emulates gcov version 4.2.0 Usage: llvm-cov {export|gcov|report|show} [OPTION]...

Shows code coverage information.

Subcommands: export: Export instrprof file to structured format. gcov: Work with the gcov format. report: Summarize instrprof style coverage information. show: Annotate source files using instrprof style coverage. Scanning . for .gcda files ... Found 20 data files in . Processing CPUDataProcessor.gcda geninfo: ERROR: /home/android/code/manifest/out/coverage/User/CPUDataProcessor.gcno: could not open file

[henry2cox]

Note that there are TWO uses of the --gcov-tool option in the command line I showed above. You appear to have used one - and also appear to have not read the man page for this and other options.

[henry2cox]

In case it was not obvious from above: you need to change your command line to

lcov --directory . --gcov-tool /home/android/code/manifest/prebuilts/clang/host/linux-x86/llvm-binutils-stable/llvm-cov --gcov-tool gcov --capture -o covin.info --no-external

Basically: tell lcov that your command is llvm-cov gcov myfile.gcda .... In the man pages, this is referred to as '-Xlinker' flag behaviour - as gcc uses exactly this same idiom.

[henry2cox]

Any update on this issue? My strong suspicion is that it is resolved and this issue can be closed.

Other LLVM users might also find useful suggestions in #234.

[henry2cox]

As discussed above: I believe that this issue is resolved - and so will close it now. If there is still a problem: please either reopen this issue or file a new one. Include a detailed description of the problem, and ideally a testcase which illustrates the issue. Henry