Re: [PATCH v2] perf/build: fix broken dependency check for libtracefs

[Arnaldo Carvalho de Melo <acme@kernel.org>]

Em Tue, Jul 11, 2023 at 03:53:38PM +0200, Thomas Richter escreveu:
> Perf build auto-detects features and packages already installed
> for its build. This is done in directory tools/build/feature. This
> directory contains small sample programs. When they successfully
> compile the necessary prereqs in form of libraries and header
> files are present.
> 
> Such a check is also done for libtracefs. And this check fails:
> 
> Output before:
>  # rm -f test-libtracefs.bin; make test-libtracefs.bin
>  gcc  -MD -Wall -Werror -o test-libtracefs.bin test-libtracefs.c \
> 	 > test-libtracefs.make.output 2>&1 -ltracefs
>  make: *** [Makefile:211: test-libtracefs.bin] Error 1
>  # cat test-libtracefs.make.output
>  In file included from test-libtracefs.c:2:
>  /usr/include/tracefs/tracefs.h:11:10: fatal error: \
> 	 event-parse.h: No such file or directory
>    11 | #include <event-parse.h>
>       |          ^~~~~~~~~~~~~~~
>  compilation terminated.
>  #
> 
> The root cause of this compile error is
> commit 880885d9c22e ("libtracefs: Remove "traceevent/" from referencing libtraceevent headers")
> in the libtracefs project hosted here:
>  https://git.kernel.org/pub/scm/libs/libtrace/libtracefs.git/
> 
> That mentioned patch removes the traceevent/ directory name from
> the include statement, causing the file not to be included even
> when the libtraceevent-devel package is installed. This package contains
> the file referred to in tracefs/tracefs.h:
>  # rpm -ql libtraceevent-devel
>  /usr/include/traceevent
>  /usr/include/traceevent/event-parse.h  <----- here
>  /usr/include/traceevent/event-utils.h
>  /usr/include/traceevent/kbuffer.h
>  /usr/include/traceevent/trace-seq.h
>  /usr/lib64/libtraceevent.so
>  /usr/lib64/pkgconfig/libtraceevent.pc
>  #
> 
> With this patch the compile succeeds.
> 
> Output after:
>  # rm -f test-libtracefs.bin; make test-libtracefs.bin
>  gcc  -MD -Wall -Werror -o test-libtracefs.bin test-libtracefs.c \
> 	 > test-libtracefs.make.output 2>&1 -I/usr/include/traceevent -ltracefs
>  #

Thanks! I test it like this:

Committer testing:

  $ make -k BUILD_BPF_SKEL=1 CORESIGHT=1 O=/tmp/build/perf-tools -C tools/perf install-bin

Before:

  $ cat /tmp/build/perf-tools/feature/test-libtracefs.make.output
  In file included from test-libtracefs.c:2:
  /usr/include/tracefs/tracefs.h:11:10: fatal error: event-parse.h: No such file or directory
     11 | #include <event-parse.h>
        |          ^~~~~~~~~~~~~~~
  compilation terminated.
  $
  $ grep -i tracefs /tmp/build/perf-tools/FEATURE-DUMP
  feature-libtracefs=0
  $

After:

  $ cat /tmp/build/perf-tools/feature/test-libtracefs.make.output
  $
  $ grep -i tracefs /tmp/build/perf-tools/FEATURE-DUMP
  feature-libtracefs=1
  $

Applied to perf-tools, for v6.5.

- Arnaldo