I have a C program which I compile with -fprofile-arcs -ftest-coverage flags.Then I run the program on 5 different inputs, this will override the .gcda file and give me a combined report.But I want to have the coverage report of individual tests and store them in a folder and when I run any coverage tool on this folder I get report for each test as well as a combined report.Is there a way to do this?
Both gcovr and lcov can merge coverage data from multiple runs, but gcov has no built-in functionality.
Gcovr 5.0 added the -a/--add-tracefile option which can be used to merge multiple coverage runs. After each test, use gcovr to create a JSON report. Afterwards, you can use gcovr -a cov1.json -a cov2.json to merge multiple coverage data sets and generate a report in the format of your choosing. You can add as many input JSON files as you want, and use a glob pattern (like gcovr -a 'coverage-*.json') if you have many files.
You can also consider whether using the lcov tool with its --add-tracefile option would work: You can run lcov after each test to generate an lcov-tracefile (which you can turn into a HTML report with genhtml). Afterwards, you can merge the tracefiles into a combined report. It is not possible to use lcov's tracefiles with gcovr.