On Mon, Jun 20, 2016 at 11:38:18AM -0300, Arnaldo Carvalho de Melo wrote: > Em Mon, Jun 20, 2016 at 11:29:13AM +0800, Wangnan (F) escreveu: > > On 2016/6/17 0:48, Arnaldo Carvalho de Melo wrote: > > >Em Thu, Jun 16, 2016 at 08:02:41AM +0000, Wang Nan escreveu: > > >>With '--dry-run', 'perf record' doesn't do reall recording. Combine with > > >>llvm.dump-obj option, --dry-run can be used to help compile BPF objects > > >>for > > >>embedded platform. > > >So these are nice and have value, but can we have a subcommand to do all > > >this with an expressive name, Something like: > > > > perf bpfcc foo.c -o foo > > > >or shorter: > > > > perf bcc foo.c -o foo > > > >Just like one would use gcc or some other compiler to generate something > > >for later use? > > > I'll try it today. I thought a subcommand require a bigger feature, > > and wrapping clang is not big enough. > > Not really, we may have as many as we like, given that they provide > something useful, like I think is the case here. > > Having to edit ~/.perfconfig, create a new section, a variable in it > with a boolean value (at first, just reading the changeset comment, I > thought I had to provide a directory where to store the objects > "dumped"), to then use a tool to record a .c event, but not recording > (use dry-run, which is useful to test the command line, etc), to then > get, on the current directory, the end result looked to me a convoluted > way to ask perf to compile the given .c file into a .o for later use. > > Doing: > > perf bcc -c foo.c > > Looks so much simpler and similar to an existing compile source code > into object file workflow (gcc's, any C compiler) that I think it would > fit in the workflow being discussed really nicely.
I'm hopeful that eventually we'll be able merge iovisor/bcc project with perf, so would be good to reserve 'perf bcc' command for that future use. Also picking a different name for compiling would be less confusing to users who already familiar with bcc. Instead we can use: perf bpfcc foo.c -o foo.o perf cc foo.c perf compile foo.c
