perf build: Improve error message for old/missing clang

clang is required to build perf with BUILD_BPF_SKEL=1. Improve the
error message to highlight that:

  1) clang could be either missing or too old;
  2) clang is only required with BUILD_BPF_SKEL=1.

Suggested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Song Liu <song@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
Song Liu 2021-05-09 23:49:17 -07:00 committed by Arnaldo Carvalho de Melo
parent 8df12cbc0f
commit efb0b23281

View File

@ -635,7 +635,7 @@ endif
ifdef BUILD_BPF_SKEL
$(call feature_check,clang-bpf-co-re)
ifeq ($(feature-clang-bpf-co-re), 0)
dummy := $(error Error: clang too old. Please install recent clang)
dummy := $(error Error: clang too old/not installed. Please install recent clang to build with BUILD_BPF_SKEL)
endif
$(call detected,CONFIG_PERF_BPF_SKEL)
CFLAGS += -DHAVE_BPF_SKEL