inconsistent branch coverage summary

[icsfy]

lcov: LCOV version 2.1-1 test.cpp:

#include <stdio.h>
int func1(int n)
{
        if (n < 5)
                return n+10;
        return n+100;
}

int main(int argc, char *argv[])
{
        int a[100];

        a[argc] = func1(argc);
        if (a[argc])
                printf("111\n");
}

compile and run:

# g++ --coverage test.cpp
# ./a.out
111

use --rc no_exception_branch=1 and then use --summary to show the output .info:

[root@a6ee5ca3eff6 ~]# lcov -c -d . -o 1.info --branch --rc no_exception_branch=1
Capturing coverage data from .
geninfo cmd: '/usr/bin/geninfo . --output-filename 1.info --rc no_exception_branch=1 --branch-coverage'
Found gcov version: 14.1.1
Using intermediate gcov format
Recording 'internal' directories:
        /root
Writing temporary data to /tmp/geninfo_datNd7H
Scanning . for .gcda files ...
Found 1 data files in .
using: chunkSize: 1, nchunks:1, intervalLength:0
Finished processing 1 GCDA file
Apply filtering..
Finished filter file processing
Finished .info-file creation
Summary coverage rate:
  source files: 1
  lines.......: 88.9% (8 of 9 lines)
  functions...: 100.0% (2 of 2 functions)
  branches....: 60.0% (3 of 5 branches)
Message summary:
  no messages were reported
[root@a6ee5ca3eff6 ~]# lcov --summary 1.info --branch
Reading tracefile 1.info.
Summary coverage rate:
  source files: 1
  lines.......: 88.9% (8 of 9 lines)
  functions...: 100.0% (2 of 2 functions)
  branches....: 50.0% (2 of 4 branches)
Message summary:
  no messages were reported

The branch coverage summary first gives branches....: 60.0% (3 of 5 branches), but later is branches....: 50.0% (2 of 4 branches)

And man lcovrc tells:

The value no_exception_branch = 1 is equivalent to the --filter exception command line option.

but --filter does not recognize 'exception': geninfo: ERROR: unknown argument for --filter: 'exception'. And there is a exception argument which belongs to --ignore-errors option in man genhtml:

              exception:
                 Exclude  branches  related  to  C++  exception handling from branch coverage.  Whether C++ exception
                 branches are identified and removed is dependent on your compiler/toolchain correctly  marking  them
                 in the generated coverage data.  See the no_exception_branch section of man lcovrc(5).

[henry2cox]

The first issue was an accounting bug - fixed in eb5bd65591. (It also turns out that at least one of the lcov regression tests exposed the bug - but was not sensitive to the difference and did not notice. Sigh.)

The second appears to be a misunderstanding or an inconsistency in your environment/configuration.

• the lcov/2.1-1 release is from SHA 6141622d71, tagged/released on 10 April 2024.
• the exception (and orphan) filters were added in SHA e5e6355ccc42d4 - which was pushed sometime around 24 April. The feature is not part of the 2.1-1 release - and I do not think it is mentioned in the man pages of the release. I'm not sure which combination of code and doc you have or how you got them, but you may want to start fresh with a clean clone of TOT (or the 2.1 release - whichever you prefer) - to ensure consistency.
• there was a bug in the man page in e5e6355ccc42d4, where I put the filter description in the wrong section and didn't notice until recently. That is also fixed in the above commit.

In any event: please try your testcase again with this update - and close the issue if it appears fixed (or update the description to explain the new problem and how to see it).

Thanks

Henry