[PATCH 3/6] perf tools: Makefile: PYTHON{,_CONFIG} to bandage Python 3 incompatibility

From: Arnaldo Carvalho de Melo
Date: Wed Apr 20 2011 - 12:25:11 EST


From: Michael Witten <mfwitten@xxxxxxxxx>

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@xxxxxxxxxxx>

for motivating this patch.

Acked-by: Raghavendra D Prabhu <rprabhu@xxxxxxxxxxx>
Link: http://lkml.kernel.org/r/e987828e-87ec-4973-95e7-47f10f5d9bab-mfwitten@xxxxxxxxx
Signed-off-by: Michael Witten <mfwitten@xxxxxxxxx>
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
tools/perf/Makefile | 97 +++++++++++++++++-----
tools/perf/config/utilities.mak | 180 +++++++++++++++++++++++++++++++++++++++
tools/perf/feature-tests.mak | 8 ++-
3 files changed, 264 insertions(+), 21 deletions(-)
create mode 100644 tools/perf/config/utilities.mak

diff --git a/tools/perf/Makefile b/tools/perf/Makefile
index aaf4dd3..b5276c7 100644
--- a/tools/perf/Makefile
+++ b/tools/perf/Makefile
@@ -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
diff --git a/tools/perf/config/utilities.mak b/tools/perf/config/utilities.mak
new file mode 100644
index 0000000..6d8ff88
--- /dev/null
+++ b/tools/perf/config/utilities.mak
@@ -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))
diff --git a/tools/perf/feature-tests.mak b/tools/perf/feature-tests.mak
index b041ca6..1b33420 100644
--- a/tools/perf/feature-tests.mak
+++ b/tools/perf/feature-tests.mak
@@ -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();
--
1.6.2.5

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