perf tools: Makefile: PYTHON{,_CONFIG} to bandage Python 3 incompatibility

Currently, Python 3 is not supported by perf's code; this
can cause the build to fail for systems that have Python 3
installed as the default python:

  python{,-config}

The Correct Solution is to write compatibility code so that
Python 3 works out-of-the-box.

However, users often have an ancillary Python 2 installed:

  python2{,-config}

Therefore, a quick fix is to allow the user to specify those
ancillary paths as the python binaries that Makefile should
use, thereby avoiding Python 3 altogether; as an added benefit,
the Python binaries may be installed in non-standard locations
without the need for updating any PATH variable.

This commit adds the ability to set PYTHON and/or PYTHON_CONFIG
either as environment variables or as make variables on the
command line; the paths may be relative, and usually only PYTHON
is necessary in order for PYTHON_CONFIG to be defined implicitly.
Some rudimentary error checking is performed when the user
explicitly specifies a value for any of these variables.

In addition, this commit introduces significantly robust makefile
infrastructure for working with paths and communicating with the
shell; it's currently only used for handling Python, but I hope
it will prove useful in refactoring the makefiles.

Thanks to:

  Raghavendra D Prabhu <rprabhu@wnohang.net>

for motivating this patch.

Acked-by: Raghavendra D Prabhu <rprabhu@wnohang.net>
Link: http://lkml.kernel.org/r/e987828e-87ec-4973-95e7-47f10f5d9bab-mfwitten@gmail.com
Signed-off-by: Michael Witten <mfwitten@gmail.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
Michael Witten 2011-04-02 21:46:09 +00:00 committed by Arnaldo Carvalho de Melo
parent 3643b133f2
commit ced465c400
3 changed files with 264 additions and 21 deletions

View file

@ -5,6 +5,8 @@ endif
# The default target of this Makefile is...
all:
include config/utilities.mak
ifneq ($(OUTPUT),)
# check that the output directory actually exists
OUTDIR := $(shell cd $(OUTPUT) && /bin/pwd)
@ -13,6 +15,12 @@ endif
# Define V to have a more verbose compile.
#
# Define PYTHON to point to the python binary if the default
# `python' is not correct; for example: PYTHON=python2
#
# Define PYTHON_CONFIG to point to the python-config binary if
# the default `$(PYTHON)-config' is not correct.
#
# Define ASCIIDOC8 if you want to format documentation with AsciiDoc 8
#
# Define DOCBOOK_XSL_172 if you want to format man pages with DocBook XSL v1.72.
@ -165,7 +173,7 @@ grep-libs = $(filter -l%,$(1))
strip-libs = $(filter-out -l%,$(1))
$(OUTPUT)python/perf.so: $(PYRF_OBJS)
$(QUIET_GEN)CFLAGS='$(BASIC_CFLAGS)' python util/setup.py \
$(QUIET_GEN)CFLAGS='$(BASIC_CFLAGS)' $(PYTHON_WORD) util/setup.py \
--quiet build_ext \
--build-lib='$(OUTPUT)python' \
--build-temp='$(OUTPUT)python/temp'
@ -473,24 +481,74 @@ else
endif
endif
ifdef NO_LIBPYTHON
BASIC_CFLAGS += -DNO_LIBPYTHON
disable-python = $(eval $(disable-python_code))
define disable-python_code
BASIC_CFLAGS += -DNO_LIBPYTHON
$(if $(1),$(warning No $(1) was found))
$(warning Python support won't be built)
endef
override PYTHON := \
$(call get-executable-or-default,PYTHON,python)
ifndef PYTHON
$(call disable-python,python interpreter)
python-clean :=
else
PYTHON_EMBED_LDOPTS = $(shell python-config --ldflags 2>/dev/null)
PYTHON_EMBED_LDFLAGS = $(call strip-libs,$(PYTHON_EMBED_LDOPTS))
PYTHON_EMBED_LIBADD = $(call grep-libs,$(PYTHON_EMBED_LDOPTS))
PYTHON_EMBED_CCOPTS = `python-config --cflags 2>/dev/null`
FLAGS_PYTHON_EMBED=$(PYTHON_EMBED_CCOPTS) $(PYTHON_EMBED_LDOPTS)
ifneq ($(call try-cc,$(SOURCE_PYTHON_EMBED),$(FLAGS_PYTHON_EMBED)),y)
msg := $(warning No Python.h found, install python-dev[el] to have python support in 'perf script' and to build the python bindings)
BASIC_CFLAGS += -DNO_LIBPYTHON
else
ALL_LDFLAGS += $(PYTHON_EMBED_LDFLAGS)
EXTLIBS += $(PYTHON_EMBED_LIBADD)
LIB_OBJS += $(OUTPUT)util/scripting-engines/trace-event-python.o
LIB_OBJS += $(OUTPUT)scripts/python/Perf-Trace-Util/Context.o
LANG_BINDINGS += $(OUTPUT)python/perf.so
endif
PYTHON_WORD := $(call shell-wordify,$(PYTHON))
python-clean := $(PYTHON_WORD) util/setup.py clean \
--build-lib='$(OUTPUT)python' \
--build-temp='$(OUTPUT)python/temp'
ifdef NO_LIBPYTHON
$(call disable-python)
else
override PYTHON_CONFIG := \
$(call get-executable-or-default,PYTHON_CONFIG,$(PYTHON)-config)
ifndef PYTHON_CONFIG
$(call disable-python,python-config tool)
else
PYTHON_CONFIG_SQ := $(call shell-sq,$(PYTHON_CONFIG))
PYTHON_EMBED_LDOPTS := $(shell $(PYTHON_CONFIG_SQ) --ldflags 2>/dev/null)
PYTHON_EMBED_LDFLAGS := $(call strip-libs,$(PYTHON_EMBED_LDOPTS))
PYTHON_EMBED_LIBADD := $(call grep-libs,$(PYTHON_EMBED_LDOPTS))
PYTHON_EMBED_CCOPTS := $(shell $(PYTHON_CONFIG_SQ) --cflags 2>/dev/null)
FLAGS_PYTHON_EMBED := $(PYTHON_EMBED_CCOPTS) $(PYTHON_EMBED_LDOPTS)
ifneq ($(call try-cc,$(SOURCE_PYTHON_EMBED),$(FLAGS_PYTHON_EMBED)),y)
$(call disable-python,Python.h (for Python 2.x))
else
ifneq ($(call try-cc,$(SOURCE_PYTHON_VERSION),$(FLAGS_PYTHON_EMBED)),y)
$(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
ALL_LDFLAGS += $(PYTHON_EMBED_LDFLAGS)
EXTLIBS += $(PYTHON_EMBED_LIBADD)
LIB_OBJS += $(OUTPUT)util/scripting-engines/trace-event-python.o
LIB_OBJS += $(OUTPUT)scripts/python/Perf-Trace-Util/Context.o
LANG_BINDINGS += $(OUTPUT)python/perf.so
endif
endif
endif
endif
endif
ifdef NO_DEMANGLE
@ -831,8 +889,7 @@ clean:
$(RM) *.spec *.pyc *.pyo */*.pyc */*.pyo $(OUTPUT)common-cmds.h TAGS tags cscope*
$(MAKE) -C Documentation/ clean
$(RM) $(OUTPUT)PERF-VERSION-FILE $(OUTPUT)PERF-CFLAGS
@python util/setup.py clean --build-lib='$(OUTPUT)python' \
--build-temp='$(OUTPUT)python/temp'
$(python-clean)
.PHONY: all install clean strip
.PHONY: shell_compatibility_test please_set_SHELL_PATH_to_a_more_modern_shell

View file

@ -0,0 +1,180 @@
# This allows us to work with the newline character:
define newline
endef
newline := $(newline)
# nl-escape
#
# Usage: escape = $(call nl-escape[,escape])
#
# This is used as the common way to specify
# what should replace a newline when escaping
# newlines; the default is a bizarre string.
#
nl-escape = $(or $(1),m822df3020w6a44id34bt574ctac44eb9f4n)
# escape-nl
#
# Usage: escaped-text = $(call escape-nl,text[,escape])
#
# GNU make's $(shell ...) function converts to a
# single space each newline character in the output
# produced during the expansion; this may not be
# desirable.
#
# The only solution is to change each newline into
# something that won't be converted, so that the
# information can be recovered later with
# $(call unescape-nl...)
#
escape-nl = $(subst $(newline),$(call nl-escape,$(2)),$(1))
# unescape-nl
#
# Usage: text = $(call unescape-nl,escaped-text[,escape])
#
# See escape-nl.
#
unescape-nl = $(subst $(call nl-escape,$(2)),$(newline),$(1))
# shell-escape-nl
#
# Usage: $(shell some-command | $(call shell-escape-nl[,escape]))
#
# Use this to escape newlines from within a shell call;
# the default escape is a bizarre string.
#
# NOTE: The escape is used directly as a string constant
# in an `awk' program that is delimited by shell
# single-quotes, so be wary of the characters
# that are chosen.
#
define shell-escape-nl
awk 'NR==1 {t=$$0} NR>1 {t=t "$(nl-escape)" $$0} END {printf t}'
endef
# shell-unescape-nl
#
# Usage: $(shell some-command | $(call shell-unescape-nl[,escape]))
#
# Use this to unescape newlines from within a shell call;
# the default escape is a bizarre string.
#
# NOTE: The escape is used directly as an extended regular
# expression constant in an `awk' program that is
# delimited by shell single-quotes, so be wary
# of the characters that are chosen.
#
# (The bash shell has a bug where `{gsub(...),...}' is
# misinterpreted as a brace expansion; this can be
# overcome by putting a space between `{' and `gsub').
#
define shell-unescape-nl
awk 'NR==1 {t=$$0} NR>1 {t=t "\n" $$0} END { gsub(/$(nl-escape)/,"\n",t); printf t }'
endef
# escape-for-shell-sq
#
# Usage: embeddable-text = $(call escape-for-shell-sq,text)
#
# This function produces text that is suitable for
# embedding in a shell string that is delimited by
# single-quotes.
#
escape-for-shell-sq = $(subst ','\'',$(1))
# shell-sq
#
# Usage: single-quoted-and-escaped-text = $(call shell-sq,text)
#
shell-sq = '$(escape-for-shell-sq)'
# shell-wordify
#
# Usage: wordified-text = $(call shell-wordify,text)
#
# For instance:
#
# |define text
# |hello
# |world
# |endef
# |
# |target:
# | echo $(call shell-wordify,$(text))
#
# At least GNU make gets confused by expanding a newline
# within the context of a command line of a makefile rule
# (this is in constrast to a `$(shell ...)' function call,
# which can handle it just fine).
#
# This function avoids the problem by producing a string
# that works as a shell word, regardless of whether or
# not it contains a newline.
#
# If the text to be wordified contains a newline, then
# an intrictate shell command substitution is constructed
# to render the text as a single line; when the shell
# processes the resulting escaped text, it transforms
# it into the original unescaped text.
#
# If the text does not contain a newline, then this function
# produces the same results as the `$(shell-sq)' function.
#
shell-wordify = $(if $(findstring $(newline),$(1)),$(_sw-esc-nl),$(shell-sq))
define _sw-esc-nl
"$$(echo $(call escape-nl,$(shell-sq),$(2)) | $(call shell-unescape-nl,$(2)))"
endef
# is-absolute
#
# Usage: bool-value = $(call is-absolute,path)
#
is-absolute = $(shell echo $(shell-sq) | grep ^/ -q && echo y)
# lookup
#
# Usage: absolute-executable-path-or-empty = $(call lookup,path)
#
# (It's necessary to use `sh -c' because GNU make messes up by
# trying too hard and getting things wrong).
#
lookup = $(call unescape-nl,$(shell sh -c $(_l-sh)))
_l-sh = $(call shell-sq,command -v $(shell-sq) | $(call shell-escape-nl,))
# is-executable
#
# Usage: bool-value = $(call is-executable,path)
#
# (It's necessary to use `sh -c' because GNU make messes up by
# trying too hard and getting things wrong).
#
is-executable = $(call _is-executable-helper,$(shell-sq))
_is-executable-helper = $(shell sh -c $(_is-executable-sh))
_is-executable-sh = $(call shell-sq,test -f $(1) -a -x $(1) && echo y)
# get-executable
#
# Usage: absolute-executable-path-or-empty = $(call get-executable,path)
#
# The goal is to get an absolute path for an executable;
# the `command -v' is defined by POSIX, but it's not
# necessarily very portable, so it's only used if
# relative path resolution is requested, as determined
# by the presence of a leading `/'.
#
get-executable = $(if $(1),$(if $(is-absolute),$(_ge-abspath),$(lookup)))
_ge-abspath = $(if $(is-executable),$(1))
# get-supplied-or-default-executable
#
# Usage: absolute-executable-path-or-empty = $(call get-executable-or-default,variable,default)
#
define get-executable-or-default
$(if $($(1)),$(call _ge_attempt,$($(1)),$(1)),$(call _ge_attempt,$(2)))
endef
_ge_attempt = $(or $(get-executable),$(_gea_warn),$(call _gea_err,$(2)))
_gea_warn = $(warning The path '$(1)' is not executable.)
_gea_err = $(if $(1),$(error Please set '$(1)' appropriately))

View file

@ -79,9 +79,15 @@ endef
endif
ifndef NO_LIBPYTHON
define SOURCE_PYTHON_VERSION
#include <Python.h>
#if PY_VERSION_HEX >= 0x03000000
#error
#endif
int main(void){}
endef
define SOURCE_PYTHON_EMBED
#include <Python.h>
int main(void)
{
Py_Initialize();