Paul Menzel wrote: > Dear Márton, > > > Am Sonntag, den 22.04.2012, 08:38 +0200 schrieb Németh Márton: >> From: Márton Németh <nm...@freemail.hu> > > I would change the commit summary to the following. > > build: add instructions for GCC’s code coverage feature > > But I am not too sure about the terminology.
Yes, this is GCC's code coverage. Maybe we can add reference to GNU gcov: http://gcc.gnu.org/onlinedocs/gcc/Gcov.html . >> Signed-off-by: Márton Németh <nm...@freemail.hu> >> --- >> diff --git a/Makefile b/Makefile >> index 22096dc..073843c 100644 >> --- a/Makefile >> +++ b/Makefile >> @@ -4,6 +4,7 @@ VERSION := 1.98 >> >> CXXFLAGS ?= -O2 -g -fno-omit-frame-pointer -fstack-protector >> CXXFLAGS += -Wall -Wshadow -Wformat >> +#CXXFLAGS += --coverage >> CPPFLAGS += -D_FORTIFY_SOURCE=2 >> PKG_CONFIG ?= pkg-config >> >> diff --git a/README b/README >> index c44f56c..e03e568 100644 >> --- a/README >> +++ b/README >> @@ -109,3 +109,26 @@ powertop --extech=/dev/ttyUSB0 >> (where ttyUSB0 is the devicenode of the serial-to-usb adapter on my system) >> >> >> +Creating code coverage report for powertop >> +------------------------------------------ >> +Code coverage is a method to find out which part of the code was executed >> and >> +which was not executed. The gcc compiler supports creating such measurements > > Has that feature always been there or is a certain GCC version needed? I don't remember exactly from which GCC version this "--coverage" was added. I'm currently using "gcc (Debian 4.4.6-14) 4.4.6", that works for sure. Earlier two other options had to be used: "-fprofile-arcs -ftest-coverage". >> +on the code by instrumenting the code at compile time when the "--coverage" >> +option is given. You can enable this for powertop in the top level Makefile >> +by uncommenting the line "CXXFLAGS += --coverage". After this a full >> recompile >> +is needed. At this point different test cases can be executed on powertop >> +binary. Once the testing is ready the tools "lcov" and "genhtml" can be >> +used to generate nice HTML report on the code coverage. >> + >> +# (edit Makefile to enable --coverage option) >> +# make clean >> +# make >> +# (execute test cases for powertop. May contain multiple powertop runs. The >> results are accumulated.) >> +# lcov --base-directory . --directory . -c -o powertop.info >> +# genhtml -o powertop_coverage powertop.info >> +# (open powertop_coverage/index.html in a browser) >> + >> +Note that the code coverage figures are mainly speaking about the quality >> +of the testing. It has limitations also, even if you achieve 100% code >> coverage >> +you won't be detect a missing piece of code (e.g. error handling) only by > > … you won’t be able … > >> +watching at the code coverage figures. > > s,watching,looking, > > Acked-by: Paul Menzel <paulepan...@users.sourceforge.net> Should I merge these changes and resend the patch for a new review? Regards, Márton Németh _______________________________________________ Power mailing list Power@bughost.org https://bughost.org/mailman/listinfo/power
