genhtml (2.0) dies with source files in top directory

[entrope]

When there is a source file in the top-level directory of a project (one of the directories passed with --prefix), the die("file error for " ...) call gets triggered: @$short_path has only one element, so nothing gets passed to File::Spec->catdir() and $rel_dir is empty.

Adding unshift @$short_path, '.' if $#$short_path == 0; before the call to catdir() avoids the crash but generates an HTML coverage report with no way to access the source files because the top-level directory has a zero-length (or no?) hyperlink to the per-directory report file.

With lcov 1.16, this would give the name "root" to the top-level directory.

[henry2cox]

better if you could attach a testcase. Other question is what happens when your remove the --prefix option. Thanks.

[entrope]

This was on macOS 14.1 (Sonoma) using Apple's version of LLVM 15 as cc, but should translate well to Linux. (I reproduced my original case, which uses Meson as a build system, in a Kali Linux VM because that was what had lcov 2.0).

% echo "int main() { return 0; }" > main.c
% cc -Wall -Wextra --coverage ../main.c
% ./a.out
% lcov -c -d `pwd` -o lcov.info
[...]
% genhtml -o html --prefix `pwd` lcov.info
Found 1 entries.
Using user-specified filename prefix "/Users/mdpoole/src/tmp"
Generating output.
genhtml: ERROR: file error for main.c

Meson automatically adds --prefix, so it is not easy for my original case to remove it. Without --prefix in the test case above, it finds the parent directory as the prefix:

% genhtml -o html lcov.info 
Found 1 entries.
Found common filename prefix "/Users/mdpoole/src"
Generating output.
Processing file tmp/main.c
  lines=1 hit=1 functions=1 hit=1
Overall coverage rate:
  lines......: 100.0% (1 of 1 line)
  functions......: 100.0% (1 of 1 function)

[henry2cox]

Thanks. I suspect that your actual case is not quite so simple :-) Probably contains code in subdirectories of 'prefix' as well as in the top-level directory. I also wanted to test that my somewhat hacky fix handles --flat and --hierarchical report formats.

In any event: I seem to have a fix which I will push along with some other changes/enhancements - once local tests are complete and things seem to have stabilized.

Henry

[entrope]

My actual case is almost that simple -- I have multiple source files, but all were in the top-level directory. (I have since restructured it to have subdirectories, to clarify library vs executable code.)

I am happy to test your fix on my original test case once you think it is worth sharing. Thank you for the quick responses.

[henry2cox]

should be fixed in the above commit: bf135ca

[henry2cox]

Closing this issue as I think that it is fixed. If there is still a problem, please either reopen this issue or file a new one. Please include a testcase which illustrates the problem if at all possible. Henry