With gcc's --coverage option, we can perform automatic coverage data collection for the test suite. Add a new Makefile target 'coverage' that scraps all previous coverage results, recompiles git with the required compiler/linker flags (in addition to any flags you specify manually), then runs the test suite and compiles a report. The compilation must be done with all optimizations disabled, since inlined functions (and for line-by-line coverage, also optimized branches/loops) break coverage tracking. The tests are run serially (with -j1). The coverage code should theoretically allow concurrent access to its data files, but the author saw random test failures. Obviously this could be improved. The report currently consists of a list of functions that were never executed during the tests, which is written to 'coverage-untested-functions'. Once this list becomes reasonably short, we would also want to look at branches that were never taken. Currently only toplevel *.c files are considered. It would be nice to at least include xdiff, but --coverage did not save data to subdirectories on the system used to write this (gcc 4.3.2). Signed-off-by: Thomas Rast <trast@xxxxxxxxxxxxxxx> --- Let the 'all' sub-build of 'coverage' run with the caller's -j setting so that it can parallelize. Interdiff: --- a/Makefile +++ b/Makefile @@ -21,8 +21,9 @@ +COVERAGE_LDFLAGS = $(CFLAGS) -O0 -lgcov + +coverage-build: coverage-clean ++ $(MAKE) CFLAGS="$(COVERAGE_CFLAGS)" LDFLAGS="$(COVERAGE_LDFLAGS)" all + $(MAKE) CFLAGS="$(COVERAGE_CFLAGS)" LDFLAGS="$(COVERAGE_LDFLAGS)" \ -+ -j1 all test ++ -j1 test + +coverage-report: + gcov -b *.c Makefile | 24 ++++++++++++++++++++++++ 1 files changed, 24 insertions(+), 0 deletions(-) diff --git a/Makefile b/Makefile index b040a96..c32881b 100644 --- a/Makefile +++ b/Makefile @@ -1640,3 +1640,27 @@ check-docs:: check-builtins:: ./check-builtins.sh +### Test suite coverage testing +# +.PHONY: coverage coverage-clean coverage-build coverage-report + +coverage: + $(MAKE) coverage-build + $(MAKE) coverage-report + +coverage-clean: + rm -f *.gcda *.gcno + +COVERAGE_CFLAGS = $(CFLAGS) -O0 -ftest-coverage -fprofile-arcs +COVERAGE_LDFLAGS = $(CFLAGS) -O0 -lgcov + +coverage-build: coverage-clean + $(MAKE) CFLAGS="$(COVERAGE_CFLAGS)" LDFLAGS="$(COVERAGE_LDFLAGS)" all + $(MAKE) CFLAGS="$(COVERAGE_CFLAGS)" LDFLAGS="$(COVERAGE_LDFLAGS)" \ + -j1 test + +coverage-report: + gcov -b *.c + grep '^function.*called 0 ' *.c.gcov \ + | sed -e 's/\([^:]*\)\.gcov: *function \([^ ]*\) called.*/\1: \2/' \ + | tee coverage-untested-functions -- 1.6.2.rc1.266.gce6c4 -- To unsubscribe from this list: send the line "unsubscribe git" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
