linux.git/tools/build/feature/Makefile, branch v4.12

tools build: Fix feature detection redefinion of build flags

2017-04-13T14:48:48+00:00

This change is a follow up of https://lkml.org/lkml/2017/2/2/16

The patch above avoided redefining CC, CXX and PKG_CONFIG in feature
detection. The patch was not merged due to a unsolved concern with the
-MD flag.

Later, commit c8c188679ccf ("tools build: Use the same CC for feature
detection and actual build") did the change for CC and CXX but not
PKG_CONFIG.

This patch makes PKG_CONFIG consistent with CC and CXX and moves the -MD
to CFLAGS, as suggested by Jiri in the thread above.

Signed-off-by: David Carrillo-Cisneros 
Cc: Alexander Shishkin 
Cc: Andi Kleen 
Cc: He Kuang 
Cc: Jiri Olsa 
Cc: Masami Hiramatsu 
Cc: Paul Turner 
Cc: Peter Zijlstra 
Cc: Simon Que 
Cc: Stephane Eranian 
Cc: Wang Nan 
Link: http://lkml.kernel.org/r/20170412064919.92449-3-davidcc@google.com
Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Pass PYTHON config to feature detection

2017-04-12T13:45:21+00:00

( This is a rebased version of https://lkml.org/lkml/2017/2/7/662 )

Python's CC and link Makefile variables were not passed to feature
detection, causing feature detection to use system's Python rather than
PYTHON_CONFIG's one. This created a mismatch between the detected Python
support and the one actually used by perf when PYTHON_CONFIG is
specified.

Fix it by moving Python's variable initialization to before feature
detection and pass FLAGS_PYTHON_EMBED to Python's feature detection's
build target.

Signed-off-by: David Carrillo-Cisneros 
Acked-by: Jiri Olsa 
Cc: Alexander Shishkin 
Cc: Andi Kleen 
Cc: He Kuang 
Cc: Masami Hiramatsu 
Cc: Paul Turner 
Cc: Peter Zijlstra 
Cc: Simon Que 
Cc: Stephane Eranian 
Cc: Wang Nan 
Link: http://lkml.kernel.org/r/20170412064919.92449-2-davidcc@google.com
Signed-off-by: Arnaldo Carvalho de Melo

tools build: Use the same CC for feature detection and actual build

2017-03-03T22:07:19+00:00

	When build with: 'make CC=clang' we were not using that CC to do
feature detection, which resulted in features being detected with gcc
and then the actual tools being built with clang.

	Most of the time these compilers are compatible enough, so no
problem was being noticed.

	As soon as a system with an old enough clang, one that hasn't
the cpuid.h header is used, and a gcc with it, the "get_cpuid" feature
will be found available but then code that will use can't be compiled.

	Noticed with this combination:

  / $ gcc --version | head -1
  gcc (Alpine 6.3.0) 6.3.0
  / $ clang --version | head -1
  clang version 3.8.1 (tags/RELEASE_381/final)
  / $ cat /etc/alpine-release
  3.5.0
  / $

Cc: Adrian Hunter 
Cc: David Ahern 
Cc: Jiri Olsa 
Cc: Namhyung Kim 
Cc: Wang Nan 
Link: http://lkml.kernel.org/n/tip-60q18nvlvgpyfv7e2qqgx4ou@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

tools build: Add test for sched_getcpu()

2017-03-03T22:07:19+00:00

Instead of trying to go on adding more ifdef conditions, do a feature
test and define HAVE_SCHED_GETCPU_SUPPORT instead, then use it to
provide the prototype. No need to change the stub, as it is already a
__weak symbol.

Cc: Adrian Hunter 
Cc: David Ahern 
Cc: Jiri Olsa 
Cc: Namhyung Kim 
Cc: Wang Nan 
Link: http://lkml.kernel.org/n/tip-yge89er9g90sc0v6k0a0r5tr@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf build: Check LLVM version in feature check

2016-12-06T16:21:55+00:00

Cancel builtin llvm and clang support when LLVM version is less than
3.9.0: following commits uses newer API.

Since Clang/LLVM's API is not guaranteed to be stable, add a
test-llvm-version.cpp feature checker, issue warning if LLVM found in
compiling environment is not tested yet.

Committer Notes:

Testing it:

Environment:

  $ cat /etc/fedora-release
  Fedora release 25 (Twenty Five)
  $ rpm -q llvm-devel clang-devel
  llvm-devel-3.8.0-1.fc25.x86_64
  clang-devel-3.8.0-2.fc25.x86_64
  $

Before:

  $  make -k LIBCLANGLLVM=1 O=/tmp/build/perf -C tools/perf install-bin
  make: Entering directory '/home/acme/git/linux/tools/perf'
    BUILD:   Doing 'make -j4' parallel build
  Warning: tools/include/uapi/linux/bpf.h differs from kernel
  Warning: tools/arch/arm/include/uapi/asm/kvm.h differs from kernel
    INSTALL  GTK UI
    LINK     /tmp/build/perf/perf
  /tmp/build/perf/libperf.a(libperf-in.o): In function `perf::createCompilerInvocation(llvm::SmallVector, llvm::StringRef&, clang::DiagnosticsEngine&)':
  /home/acme/git/linux/tools/perf/util/c++/clang.cpp:56: undefined reference to `clang::tooling::newInvocation(clang::DiagnosticsEngine*, llvm::SmallVector const&)'
  /tmp/build/perf/libperf.a(libperf-in.o): In function `perf::getModuleFromSource(llvm::SmallVector, llvm::StringRef, llvm::IntrusiveRefCntPtr)':
  /home/acme/git/linux/tools/perf/util/c++/clang.cpp:68: undefined reference to `clang::CompilerInstance::CompilerInstance(std::shared_ptr, bool)'
  /home/acme/git/linux/tools/perf/util/c++/clang.cpp:69: undefined reference to `clang::CompilerInstance::createDiagnostics(clang::DiagnosticConsumer*, bool)'
  

After:

  Makefile.config:807: No suitable libLLVM found, disabling builtin clang and llvm support. Please install llvm-dev(el) (>= 3.9.0)

Updating the environment to a locally built LLVM 4.0 + clang 3.9 (forgot
to git pull, duh) combo, all works as expected, it is properly detected
and built into the resulting perf binary.

Signed-off-by: Wang Nan 
Reported-and-Tested-by: Arnaldo Carvalho de Melo 
Cc: Alexei Starovoitov 
Cc: He Kuang 
Cc: Jiri Olsa 
Cc: Joe Stringer 
Cc: Zefan Li 
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/20161206072230.7651-1-wangnan0@huawei.com
[ Change the warning message a bit (add 'suitable' and 'builtin'), clarifying it, see committer notes above ]
Signed-off-by: Arnaldo Carvalho de Melo

tools build: Move tabs to spaces where suitable

2016-12-05T19:06:03+00:00

We've been hit several times by a Makefile bug where line indented by
tab was falsely considered as target command.

We prevent this by always using space indentation for everything except
for the target commands.

Signed-off-by: Jiri Olsa 
Cc: David Ahern 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Link: http://lkml.kernel.org/r/1480884178-8072-3-git-send-email-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

tools build: Add feature detection for clang

2016-12-05T18:51:43+00:00

Check if basic clang compiling environment is ready.

Doesn't like 'llvm-config --libs' which can returns llvm libraries in right
order and duplicates some libraries if necessary, there's no correspondence for
clang libraries (-lclangxxx). to avoid extra complexity and to avoid new clang
breaking libraries ordering, use --start-group and --end-group.

In this test case, manually identify required clang libs and hope it to be
stable. Putting all clang libraries here is possible (use make's wildcard), but
then feature checking becomes very slow.

Signed-off-by: Wang Nan 
Cc: Alexei Starovoitov 
Cc: He Kuang 
Cc: Jiri Olsa 
Cc: Joe Stringer 
Cc: Zefan Li 
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/20161126070354.141764-9-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo

tools build: Add feature detection for LLVM

2016-12-05T18:51:42+00:00

Check if basic LLVM compiling environment is ready.

Use llvm-config to detect include and library directories. Avoid using
'llvm-config --cxxflags' because its result contain some unwanted flags
like --sysroot (if LLVM is built by yocto).

Use '?=' to set LLVM_CONFIG, so explicitly passing LLVM_CONFIG to make
would override it.

Use 'llvm-config --libs BPF' to check if BPF backend is compiled in.
Since now BPF bytecode is the only required backend, no need to waste
time linking llvm and clang if BPF backend is missing. This also
introduce an implicit requirement that LLVM should be new enough.  Old
LLVM doesn't support BPF backend.

Signed-off-by: Wang Nan 
Cc: Alexei Starovoitov 
Cc: He Kuang 
Cc: Jiri Olsa 
Cc: Joe Stringer 
Cc: Zefan Li 
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/20161126070354.141764-8-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo

tools build: Add jvmti feature detection support

2016-11-14T15:40:32+00:00

Adding support to detect jvmti support. It is not plugged into the
FEATURE_TESTS machinery, because it's quite rare and will be used
separately from perf via feature_check call.

Signed-off-by: Jiri Olsa 
Tested-by: Stephane Eranian 
Cc: Andi Kleen 
Cc: David Ahern 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Cc: William Cohen 
Link: http://lkml.kernel.org/r/1478093749-5602-3-git-send-email-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

tools build: Add feature detection for g++

2016-10-05T22:59:35+00:00

Check if g++ is available. The result will be used by builtin clang and
LLVM support. Since LLVM requires C++11, this feature detector checks
std::move().

Signed-off-by: Wang Nan 
Cc: Alexei Starovoitov 
Cc: He Kuang 
Cc: Jiri Olsa 
Cc: Zefan Li 
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1474874832-134786-3-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo