Re: [PATCH v2 0/8] perf build: Support building with Clang

From: Arnaldo Carvalho de Melo <acme@kernel.org>
To: Leo Yan <leo.yan@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>, Jiri Olsa <jolsa@kernel.org>,
	Ian Rogers <irogers@google.com>,
	Adrian Hunter <adrian.hunter@intel.com>,
	Nathan Chancellor <nathan@kernel.org>,
	Nick Desaulniers <nick.desaulniers+lkml@gmail.com>,
	Bill Wendling <morbo@google.com>,
	Justin Stitt <justinstitt@google.com>,
	Paul Walmsley <paul.walmsley@sifive.com>,
	Palmer Dabbelt <palmer@dabbelt.com>,
	Albert Ou <aou@eecs.berkeley.edu>,
	Alexandre Ghiti <alex@ghiti.fr>,
	James Clark <james.clark@linaro.org>,
	linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org,
	llvm@lists.linux.dev, linux-riscv@lists.infradead.org
Subject: Re: [PATCH v2 0/8] perf build: Support building with Clang
Date: Wed, 1 Oct 2025 11:21:20 -0300	[thread overview]
Message-ID: <aN044EY-Ds9-E6iz@x1> (raw)
In-Reply-To: <20250930-perf_build_android_ndk-v2-0-2ea440b7ef01@arm.com>

On Tue, Sep 30, 2025 at 05:54:48PM +0100, Leo Yan wrote:
> This series adds support for building perf with Clang, following the
> discussion in [1]. Because the Android NDK uses Clang by default,
> enabling Clang builds naturally covers Android as well.
> 
> The series is organized as follows:
> 
>   - Patches 1–2: Fix two bugs found with Clang.
>   - Patches 3–6: Correct CROSS_ARCH and dismiss Clang build warnings.
>   - Patches 7–8: Enable Clang in the Makefile and update the
>     documentation.
> 
> Testing:
> 
>   - Clang 15.0.7 on Ubuntu 22.04.5: native and cross-compiling (aarch64)
>   - Clang 18.1.3 on Ubuntu 24.04.2: native and cross-compiling (aarch64)
>   - Android NDK r27d (latest LTS): cross-compiling (aarch64)

  LD      /tmp/build/perf/util/perf-util-in.o
  LD      /tmp/build/perf/perf-util-in.o
  AR      /tmp/build/perf/libperf-util.a
  CC      /tmp/build/perf/pmu-events/pmu-events.o
  LD      /tmp/build/perf/pmu-events/pmu-events-in.o
  AR      /tmp/build/perf/libpmu-events.a
  LINK    /tmp/build/perf/perf
make: Leaving directory '/git/perf-6.17.0-rc6/tools/perf'
+ rm -rf /tmp/build/perf
+ mkdir /tmp/build/perf
+ make 'ARCH=' 'CROSS_COMPILE=' 'EXTRA_CFLAGS=' -C tools/perf 'O=/tmp/build/perf' 'CC=clang'
make: Entering directory '/git/perf-6.17.0-rc6/tools/perf'
  BUILD:   Doing 'make -j28' parallel build
Makefile.config:494: *** No gnu/libc-version.h found, please install glibc-dev[el].  Stop.
make[1]: *** [Makefile.perf:289: sub-make] Error 2
make: *** [Makefile:76: all] Error 2
make: Leaving directory '/git/perf-6.17.0-rc6/tools/perf'
+ exit 1
toolsbuilder@five:~$ cat dm.log/alpine\:3.22