`llvm-cov convert-for-testing` is used to build the .covmapping files used in its regression tests. However the current implementation only works when there's only one source file in the mapping information data. If there are more than 1 source files, `llvm-cov convert-for-testing` can still produce a .covmapping file, but when read it back, `llvm-cov` will report:
```
error: Failed to load coverage: 'main.covmapping': Malformed coverage data
```
This is because the output .covmapping file doesn't have any mark to indicate the boundary between file records and function records, and current implementation jsut assume there's only one file record in the .covmapping file.
Changes to the code:
- Make `llvm-cov convert-for-testing` output a LEB128 number before file records to indicate its size.
- Change the testing format parsing code correspondingly.
- Update existing .covmapping files.
Reviewed By: gulfem
Differential Revision: https://reviews.llvm.org/D156611
* Fix an unsigned integer overflow in the logic that computes the
number of uncovered lines in a function.
* When aggregating region and line coverage summaries, take into account
that different instantiations may have a different number of regions.
The new test case provides test coverage for both bugs. I also verified
this change by preparing a coverage report for a stage2 build of llc --
the new assertions should detect any outstanding over-counting bugs.
Fixes PR34613.
llvm-svn: 313417
