linux/tools/build/Makefile.feature
Arnaldo Carvalho de Melo 3d1d57debe tools build: Remove needless libpython-version feature check that breaks test-all fast path
Since 66dfdff03d ("perf tools: Add Python 3 support") we don't use
the tools/build/feature/test-libpython-version.c version in any Makefile
feature check:

  $ find tools/ -type f | xargs grep feature-libpython-version
  $

The only place where this was used was removed in 66dfdff03d:

  -        ifneq ($(feature-libpython-version), 1)
  -          $(warning Python 3 is not yet supported; please set)
  -          $(warning PYTHON and/or PYTHON_CONFIG appropriately.)
  -          $(warning If you also have Python 2 installed, then)
  -          $(warning try something like:)
  -          $(warning $(and ,))
  -          $(warning $(and ,)  make PYTHON=python2)
  -          $(warning $(and ,))
  -          $(warning Otherwise, disable Python support entirely:)
  -          $(warning $(and ,))
  -          $(warning $(and ,)  make NO_LIBPYTHON=1)
  -          $(warning $(and ,))
  -          $(error   $(and ,))
  -        else
  -          LDFLAGS += $(PYTHON_EMBED_LDFLAGS)
  -          EXTLIBS += $(PYTHON_EMBED_LIBADD)
  -          LANG_BINDINGS += $(obj-perf)python/perf.so
  -          $(call detected,CONFIG_LIBPYTHON)
  -        endif

And nowadays we either build with PYTHON=python3 or just install the
python3 devel packages and perf will build against it.

But the leftover feature-libpython-version check made the fast path
feature detection to break in all cases except when python2 devel files
were installed:

  $ rpm -qa | grep python.*devel
  python3-devel-3.9.7-1.fc34.x86_64
  $ rm -rf /tmp/build/perf ; mkdir -p /tmp/build/perf ;
  $ make -C tools/perf O=/tmp/build/perf install-bin
  make: Entering directory '/var/home/acme/git/perf/tools/perf'
    BUILD:   Doing 'make -j32' parallel build
    HOSTCC  /tmp/build/perf/fixdep.o
  <SNIP>
  $ cat /tmp/build/perf/feature/test-all.make.output
  In file included from test-all.c:18:
  test-libpython-version.c:5:10: error: #error
      5 |         #error
        |          ^~~~~
  $ ldd ~/bin/perf | grep python
	libpython3.9.so.1.0 => /lib64/libpython3.9.so.1.0 (0x00007fda6dbcf000)
  $

As python3 is the norm these days, fix this by just removing the unused
feature-libpython-version feature check, making the test-all fast path
to work with the common case.

With this:

  $ rm -rf /tmp/build/perf ; mkdir -p /tmp/build/perf ;
  $ make -C tools/perf O=/tmp/build/perf install-bin |& head
  make: Entering directory '/var/home/acme/git/perf/tools/perf'
    BUILD:   Doing 'make -j32' parallel build
    HOSTCC  /tmp/build/perf/fixdep.o
    HOSTLD  /tmp/build/perf/fixdep-in.o
    LINK    /tmp/build/perf/fixdep

  Auto-detecting system features:
  ...                         dwarf: [ on  ]
  ...            dwarf_getlocations: [ on  ]
  ...                         glibc: [ on  ]
  $ ldd ~/bin/perf | grep python
	libpython3.9.so.1.0 => /lib64/libpython3.9.so.1.0 (0x00007f58800b0000)
  $ cat /tmp/build/perf/feature/test-all.make.output
  $

Reviewed-by: James Clark <james.clark@arm.com>
Fixes: 66dfdff03d ("perf tools: Add Python 3 support")
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jaroslav Škarvada <jskarvad@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/lkml/YaYmeeC6CS2b8OSz@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2021-12-06 21:57:53 -03:00

263 lines
8.4 KiB
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# SPDX-License-Identifier: GPL-2.0-only
feature_dir := $(srctree)/tools/build/feature
ifneq ($(OUTPUT),)
OUTPUT_FEATURES = $(OUTPUT)feature/
$(shell mkdir -p $(OUTPUT_FEATURES))
endif
feature_check = $(eval $(feature_check_code))
define feature_check_code
feature-$(1) := $(shell $(MAKE) OUTPUT=$(OUTPUT_FEATURES) CC="$(CC)" CXX="$(CXX)" CFLAGS="$(EXTRA_CFLAGS) $(FEATURE_CHECK_CFLAGS-$(1))" CXXFLAGS="$(EXTRA_CXXFLAGS) $(FEATURE_CHECK_CXXFLAGS-$(1))" LDFLAGS="$(LDFLAGS) $(FEATURE_CHECK_LDFLAGS-$(1))" -C $(feature_dir) $(OUTPUT_FEATURES)test-$1.bin >/dev/null 2>/dev/null && echo 1 || echo 0)
endef
feature_set = $(eval $(feature_set_code))
define feature_set_code
feature-$(1) := 1
endef
#
# Build the feature check binaries in parallel, ignore errors, ignore return value and suppress output:
#
#
# Note that this is not a complete list of all feature tests, just
# those that are typically built on a fully configured system.
#
# [ Feature tests not mentioned here have to be built explicitly in
# the rule that uses them - an example for that is the 'bionic'
# feature check. ]
#
FEATURE_TESTS_BASIC := \
backtrace \
dwarf \
dwarf_getlocations \
eventfd \
fortify-source \
get_current_dir_name \
gettid \
glibc \
libbfd \
libbfd-buildid \
libcap \
libelf \
libelf-getphdrnum \
libelf-gelf_getnote \
libelf-getshdrstrndx \
libnuma \
numa_num_possible_cpus \
libperl \
libpython \
libslang \
libslang-include-subdir \
libtraceevent \
libtracefs \
libcrypto \
libunwind \
pthread-attr-setaffinity-np \
pthread-barrier \
reallocarray \
stackprotector-all \
timerfd \
libdw-dwarf-unwind \
zlib \
lzma \
get_cpuid \
bpf \
sched_getcpu \
sdt \
setns \
libaio \
libzstd \
disassembler-four-args \
file-handle
# FEATURE_TESTS_BASIC + FEATURE_TESTS_EXTRA is the complete list
# of all feature tests
FEATURE_TESTS_EXTRA := \
bionic \
compile-32 \
compile-x32 \
cplus-demangle \
gtk2 \
gtk2-infobar \
hello \
libbabeltrace \
libbfd-liberty \
libbfd-liberty-z \
libopencsd \
libunwind-x86 \
libunwind-x86_64 \
libunwind-arm \
libunwind-aarch64 \
libunwind-debug-frame \
libunwind-debug-frame-arm \
libunwind-debug-frame-aarch64 \
cxx \
llvm \
llvm-version \
clang \
libbpf \
libpfm4 \
libdebuginfod \
clang-bpf-co-re
FEATURE_TESTS ?= $(FEATURE_TESTS_BASIC)
ifeq ($(FEATURE_TESTS),all)
FEATURE_TESTS := $(FEATURE_TESTS_BASIC) $(FEATURE_TESTS_EXTRA)
endif
FEATURE_DISPLAY ?= \
dwarf \
dwarf_getlocations \
glibc \
libbfd \
libbfd-buildid \
libcap \
libelf \
libnuma \
numa_num_possible_cpus \
libperl \
libpython \
libcrypto \
libunwind \
libdw-dwarf-unwind \
zlib \
lzma \
get_cpuid \
bpf \
libaio \
libzstd \
disassembler-four-args
# Set FEATURE_CHECK_(C|LD)FLAGS-all for all FEATURE_TESTS features.
# If in the future we need per-feature checks/flags for features not
# mentioned in this list we need to refactor this ;-).
set_test_all_flags = $(eval $(set_test_all_flags_code))
define set_test_all_flags_code
FEATURE_CHECK_CFLAGS-all += $(FEATURE_CHECK_CFLAGS-$(1))
FEATURE_CHECK_LDFLAGS-all += $(FEATURE_CHECK_LDFLAGS-$(1))
endef
$(foreach feat,$(FEATURE_TESTS),$(call set_test_all_flags,$(feat)))
#
# Special fast-path for the 'all features are available' case:
#
$(call feature_check,all,$(MSG))
#
# Just in case the build freshly failed, make sure we print the
# feature matrix:
#
ifeq ($(feature-all), 1)
#
# test-all.c passed - just set all the core feature flags to 1:
#
$(foreach feat,$(FEATURE_TESTS),$(call feature_set,$(feat)))
#
# test-all.c does not comprise these tests, so we need to
# for this case to get features proper values
#
$(call feature_check,compile-32)
$(call feature_check,compile-x32)
$(call feature_check,bionic)
$(call feature_check,libbabeltrace)
else
$(foreach feat,$(FEATURE_TESTS),$(call feature_check,$(feat)))
endif
#
# Print the result of the feature test:
#
feature_print_status = $(eval $(feature_print_status_code)) $(info $(MSG))
define feature_print_status_code
ifeq ($(feature-$(1)), 1)
MSG = $(shell printf '...%30s: [ \033[32mon\033[m ]' $(1))
else
MSG = $(shell printf '...%30s: [ \033[31mOFF\033[m ]' $(1))
endif
endef
feature_print_text = $(eval $(feature_print_text_code)) $(info $(MSG))
define feature_print_text_code
MSG = $(shell printf '...%30s: %s' $(1) $(2))
endef
#
# generates feature value assignment for name, like:
# $(call feature_assign,dwarf) == feature-dwarf=1
#
feature_assign = feature-$(1)=$(feature-$(1))
FEATURE_DUMP_FILENAME = $(OUTPUT)FEATURE-DUMP$(FEATURE_USER)
FEATURE_DUMP := $(shell touch $(FEATURE_DUMP_FILENAME); cat $(FEATURE_DUMP_FILENAME))
feature_dump_check = $(eval $(feature_dump_check_code))
define feature_dump_check_code
ifeq ($(findstring $(1),$(FEATURE_DUMP)),)
$(2) := 1
endif
endef
#
# First check if any test from FEATURE_DISPLAY
# and set feature_display := 1 if it does
$(foreach feat,$(FEATURE_DISPLAY),$(call feature_dump_check,$(call feature_assign,$(feat)),feature_display))
#
# Now also check if any other test changed,
# so we force FEATURE-DUMP generation
$(foreach feat,$(FEATURE_TESTS),$(call feature_dump_check,$(call feature_assign,$(feat)),feature_dump_changed))
# The $(feature_display) controls the default detection message
# output. It's set if:
# - detected features differes from stored features from
# last build (in $(FEATURE_DUMP_FILENAME) file)
# - one of the $(FEATURE_DISPLAY) is not detected
# - VF is enabled
ifeq ($(feature_dump_changed),1)
$(shell rm -f $(FEATURE_DUMP_FILENAME))
$(foreach feat,$(FEATURE_TESTS),$(shell echo "$(call feature_assign,$(feat))" >> $(FEATURE_DUMP_FILENAME)))
endif
feature_display_check = $(eval $(feature_check_display_code))
define feature_check_display_code
ifneq ($(feature-$(1)), 1)
feature_display := 1
endif
endef
$(foreach feat,$(FEATURE_DISPLAY),$(call feature_display_check,$(feat)))
ifeq ($(VF),1)
feature_display := 1
feature_verbose := 1
endif
feature_display_entries = $(eval $(feature_display_entries_code))
define feature_display_entries_code
ifeq ($(feature_display),1)
$(info )
$(info Auto-detecting system features:)
$(foreach feat,$(FEATURE_DISPLAY),$(call feature_print_status,$(feat),))
ifneq ($(feature_verbose),1)
$(info )
endif
endif
ifeq ($(feature_verbose),1)
TMP := $(filter-out $(FEATURE_DISPLAY),$(FEATURE_TESTS))
$(foreach feat,$(TMP),$(call feature_print_status,$(feat),))
$(info )
endif
endef
ifeq ($(FEATURE_DISPLAY_DEFERRED),)
$(call feature_display_entries)
endif