It is useful to specify CLANG="ccache clang" in order to speed up
builds. Unfortunately perf's compiler detection logic does not like
this:

    Makefile.config:704: Warning: Disabled BPF skeletons as clang (ccache clang) is missing

We don't need to know the full path to $(CLANG), so using
get-executable is not necessary. Fix by trying to run
`$(CLANG) --version` instead.

Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
---
 tools/perf/Makefile.config | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/perf/Makefile.config b/tools/perf/Makefile.config
index 5a5832ee7b53..4bc11db5aa4d 100644
--- a/tools/perf/Makefile.config
+++ b/tools/perf/Makefile.config
@@ -700,7 +700,7 @@ ifeq ($(BUILD_BPF_SKEL),1)
   else ifeq ($(filter -DHAVE_LIBBPF_SUPPORT, $(CFLAGS)),)
     $(warning Warning: Disabled BPF skeletons as libbpf is required)
     BUILD_BPF_SKEL := 0
-  else ifeq ($(call get-executable,$(CLANG)),)
+  else ifneq ($(shell $(CLANG) --version >/dev/null 2>&1; echo $$?),0)
     $(warning Warning: Disabled BPF skeletons as clang ($(CLANG)) is missing)
     BUILD_BPF_SKEL := 0
   else
-- 
2.50.1

On Tue, Aug 05, 2025 at 02:09:34PM +0200, Ilya Leoshkevich wrote:
> It is useful to specify CLANG="ccache clang" in order to speed up
> builds. Unfortunately perf's compiler detection logic does not like
> this:
> 
>     Makefile.config:704: Warning: Disabled BPF skeletons as clang (ccache clang) is missing
> 
> We don't need to know the full path to $(CLANG), so using
> get-executable is not necessary. Fix by trying to run
> `$(CLANG) --version` instead.
> 
> Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>

Acked-by: Namhyung Kim <namhyung@kernel.org>

Thanks,
Namhyung

> ---
>  tools/perf/Makefile.config | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/tools/perf/Makefile.config b/tools/perf/Makefile.config
> index 5a5832ee7b53..4bc11db5aa4d 100644
> --- a/tools/perf/Makefile.config
> +++ b/tools/perf/Makefile.config
> @@ -700,7 +700,7 @@ ifeq ($(BUILD_BPF_SKEL),1)
>    else ifeq ($(filter -DHAVE_LIBBPF_SUPPORT, $(CFLAGS)),)
>      $(warning Warning: Disabled BPF skeletons as libbpf is required)
>      BUILD_BPF_SKEL := 0
> -  else ifeq ($(call get-executable,$(CLANG)),)
> +  else ifneq ($(shell $(CLANG) --version >/dev/null 2>&1; echo $$?),0)
>      $(warning Warning: Disabled BPF skeletons as clang ($(CLANG)) is missing)
>      BUILD_BPF_SKEL := 0
>    else
> -- 
> 2.50.1
>