Re: [PATCH 1/1] perf build: Address stray '\' before # that is warned about since grep 3.8

[Ian Rogers]

On Wed, Oct 25, 2023 at 4:23 AM Arnaldo Carvalho de Melo
<acme@xxxxxxxxxx> wrote:
>
> To address this grep 3.8 warning:
>
>   grep: warning: stray \ before #
>
> We needed to remove the '' around the grep expression and keep the \
> before # so that it is escaped by the $(shell grep ...) and thus doesn't
> get to grep.
>
> We need that \ before the #, otherwise we get this:
>
>   Makefile.perf:364: *** unterminated call to function 'shell': missing ')'.  Stop.
>
> As everything after the # will be considered a comment.
>
> Removing the single quotes needs some more escaping so that _some_ of
> the escaped chars gets to grep, like the '\|' that becomes '\\\|ด.
>
> Running on debian:10, where there is no libtraceevent-devel available,
> we get:
>
>   Makefile.perf:367: *** PYTHON_EXT_SRCS= util/python.c ../lib/ctype.c util/cap.c util/evlist.c util/evsel.c util/evsel_fprintf.c util/perf_event_attr_fprintf.c util/cpumap.c util/memswap.c util/mmap.c util/namespaces.c ../lib/bitmap.c ../lib/find_bit.c ../lib/list_sort.c ../lib/hweight.c ../lib/string.c ../lib/vsprintf.c util/thread_map.c util/util.c util/cgroup.c util/parse-branch-options.c util/rblist.c util/counts.c util/print_binary.c util/strlist.c ../lib/rbtree.c util/string.c util/symbol_fprintf.c util/units.c util/affinity.c util/rwsem.c util/hashmap.c util/perf_regs.c util/fncache.c util/perf-regs-arch/perf_regs_aarch64.c util/perf-regs-arch/perf_regs_arm.c util/perf-regs-arch/perf_regs_csky.c util/perf-regs-arch/perf_regs_loongarch.c util/perf-regs-arch/perf_regs_mips.c util/perf-regs-arch/perf_regs_powerpc.c util/perf-regs-arch/perf_regs_riscv.c util/perf-regs-arch/perf_regs_s390.c util/perf-regs-arch/perf_regs_x86.c.  Stop.
>   make[1]: *** [Makefile.perf:242: sub-make] Error 2
>
> I.e. both the comments and the util/trace-event.c were removed.
>
> When using:
>
> msg := $(error PYTHON_EXT_SRCS=$(PYTHON_EXT_SRCS))
>
> While on the more recent fedora:38, with the new grep and make packages
> and libtraceevent-devel installed:
>
>   Makefile.perf:367: *** PYTHON_EXT_SRCS= util/python.c ../lib/ctype.c util/cap.c util/evlist.c util/evsel.c util/evsel_fprintf.c util/perf_event_attr_fprintf.c util/cpumap.c util/memswap.c util/mmap.c util/namespaces.c ../lib/bitmap.c ../lib/find_bit.c ../lib/list_sort.c ../lib/hweight.c ../lib/string.c ../lib/vsprintf.c util/thread_map.c util/util.c util/cgroup.c util/parse-branch-options.c util/rblist.c util/counts.c util/print_binary.c util/strlist.c util/trace-event.c ../lib/rbtree.c util/string.c util/symbol_fprintf.c util/units.c util/affinity.c util/rwsem.c util/hashmap.c util/perf_regs.c util/fncache.c util/perf-regs-arch/perf_regs_aarch64.c util/perf-regs-arch/perf_regs_arm.c util/perf-regs-arch/perf_regs_csky.c util/perf-regs-arch/perf_regs_loongarch.c util/perf-regs-arch/perf_regs_mips.c util/perf-regs-arch/perf_regs_powerpc.c util/perf-regs-arch/perf_regs_riscv.c util/perf-regs-arch/perf_regs_s390.c util/perf-regs-arch/perf_regs_x86.c.  Stop.
>   make[1]: *** [Makefile.perf:242: sub-make] Error 2
>   make: *** [Makefile:113: install-bin] Error 2
>   make: Leaving directory '/home/acme/git/perf-tools-next/tools/perf'
>   $
>
> I.e. only the comments were removed.
>
> If we build it on the same fedora:38 system, but using NO_LIBTRACEEVENT=1
>
>   $ make NO_LIBTRACEEVENT=1 CORESIGHT=1 O=/tmp/build/$(basename $PWD) -C tools/perf install-bin
>   Makefile.perf:367: *** PYTHON_EXT_SRCS= util/python.c ../lib/ctype.c util/cap.c util/evlist.c util/evsel.c util/evsel_fprintf.c util/perf_event_attr_fprintf.c util/cpumap.c util/memswap.c util/mmap.c util/namespaces.c ../lib/bitmap.c ../lib/find_bit.c ../lib/list_sort.c ../lib/hweight.c ../lib/string.c ../lib/vsprintf.c util/thread_map.c util/util.c util/cgroup.c util/parse-branch-options.c util/rblist.c util/counts.c util/print_binary.c util/strlist.c ../lib/rbtree.c util/string.c util/symbol_fprintf.c util/units.c util/affinity.c util/rwsem.c util/hashmap.c util/perf_regs.c util/fncache.c util/perf-regs-arch/perf_regs_aarch64.c util/perf-regs-arch/perf_regs_arm.c util/perf-regs-arch/perf_regs_csky.c util/perf-regs-arch/perf_regs_loongarch.c util/perf-regs-arch/perf_regs_mips.c util/perf-regs-arch/perf_regs_powerpc.c util/perf-regs-arch/perf_regs_riscv.c util/perf-regs-arch/perf_regs_s390.c util/perf-regs-arch/perf_regs_x86.c.  Stop.
>   make[1]: *** [Makefile.perf:242: sub-make] Error 2
>   make: *** [Makefile:113: install-bin] Error 2
>   make: Leaving directory '/home/acme/git/perf-tools-next/tools/perf'
>   $
>
> Both comments and the util/trace-event.c file removed.
>
> Cc: Adrian Hunter <adrian.hunter@xxxxxxxxx>
> Cc: Ian Rogers <irogers@xxxxxxxxxx>
> Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
> Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
> Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>

Acked-by: Ian Rogers <irogers@xxxxxxxxxx>

Thanks,
Ian

> ---
>  tools/perf/Makefile.perf | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/tools/perf/Makefile.perf b/tools/perf/Makefile.perf
> index 456872ac410df4c0..d80dcaa5a1e337ae 100644
> --- a/tools/perf/Makefile.perf
> +++ b/tools/perf/Makefile.perf
> @@ -361,7 +361,7 @@ python-clean := $(call QUIET_CLEAN, python) $(RM) -r $(PYTHON_EXTBUILD) $(OUTPUT
>  ifeq ($(CONFIG_LIBTRACEEVENT),y)
>    PYTHON_EXT_SRCS := $(shell grep -v ^\# util/python-ext-sources)
>  else
> -  PYTHON_EXT_SRCS := $(shell grep -v '^\#\|util/trace-event.c' util/python-ext-sources)
> +  PYTHON_EXT_SRCS := $(shell grep -v ^\#\\\|util/trace-event.c util/python-ext-sources)
>  endif
>
>  PYTHON_EXT_DEPS := util/python-ext-sources util/setup.py $(LIBAPI)
> --
> 2.41.0
>