source: kBuild/vendor/grep/current/GNUmakefile@ 3630

# Having a separate GNUmakefile lets me 'include' the dynamically
# generated rules created via cfg.mk (package-local configuration)
# as well as maint.mk (generic maintainer rules).
# This makefile is used only if you run GNU Make.
# It is necessary if you want to build targets usually of interest
# only to the maintainer.

# Copyright (C) 2001, 2003, 2006-2021 Free Software Foundation, Inc.

# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.

# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.

# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <https://www.gnu.org/licenses/>.

# If the user runs GNU make but has not yet run ./configure,
# give them a diagnostic.
_gl-Makefile := $(wildcard [M]akefile)
ifneq ($(_gl-Makefile),)

# Make tar archive easier to reproduce.
export TAR_OPTIONS = --owner=0 --group=0 --numeric-owner

# Allow the user to add to this in the Makefile.
ALL_RECURSIVE_TARGETS =

include Makefile

# Some projects override e.g., _autoreconf here.
-include $(srcdir)/cfg.mk

# Allow cfg.mk to override these.
_build-aux ?= build-aux
_autoreconf ?= autoreconf -v

include $(srcdir)/maint.mk

# Ensure that $(VERSION) is up to date for dist-related targets, but not
# for others: rerunning autoreconf and recompiling everything isn't cheap.
_have-git-version-gen := \
  $(shell test -f $(srcdir)/$(_build-aux)/git-version-gen && echo yes)
ifeq ($(_have-git-version-gen)0,yes$(MAKELEVEL))
  _is-dist-target ?= $(filter-out %clean, \
    $(filter maintainer-% dist% alpha beta stable,$(MAKECMDGOALS)))
  _is-install-target ?= $(filter-out %check, $(filter install%,$(MAKECMDGOALS)))
  ifneq (,$(_is-dist-target)$(_is-install-target))
    _curr-ver := $(shell cd $(srcdir)                           \
                   && $(_build-aux)/git-version-gen             \
                         .tarball-version                       \
                         $(git-version-gen-tag-sed-script))
    ifneq ($(_curr-ver),$(VERSION))
      ifeq ($(_curr-ver),UNKNOWN)
        $(info WARNING: unable to verify if $(VERSION) is the correct version)
      else
        ifneq (,$(_is-install-target))
          # GNU Coding Standards state that 'make install' should not cause
          # recompilation after 'make all'.  But as long as changing the version
          # string alters config.h, the cost of having 'make all' always have an
          # up-to-date version is prohibitive.  So, as a compromise, we merely
          # warn when installing a version string that is out of date; the user
          # should run 'autoreconf' (or something like 'make distcheck') to
          # fix the version, 'make all' to propagate it, then 'make install'.
          $(info WARNING: version string $(VERSION) is out of date;)
          $(info run '$(MAKE) _version' to fix it)
        else
          $(info INFO: running autoreconf for new version string: $(_curr-ver))
GNUmakefile: _version
        touch GNUmakefile
        endif
      endif
    endif
  endif
endif

.PHONY: _version
_version:
        cd $(srcdir) && rm -rf autom4te.cache .version && $(_autoreconf)
        $(MAKE) $(AM_MAKEFLAGS) Makefile

else

.DEFAULT_GOAL := abort-due-to-no-makefile
srcdir = .

# The package can override .DEFAULT_GOAL to run actions like autoreconf.
-include ./cfg.mk

# Allow cfg.mk to override these.
_build-aux ?= build-aux
_autoreconf ?= autoreconf -v

include ./maint.mk

ifeq ($(.DEFAULT_GOAL),abort-due-to-no-makefile)
$(MAKECMDGOALS): abort-due-to-no-makefile
endif

abort-due-to-no-makefile:
        @echo There seems to be no Makefile in this directory.   1>&2
        @echo "You must run ./configure before running '$(MAKE)'." 1>&2
        @exit 1

endif

# Tell version 3.79 and up of GNU make to not build goals in this
# directory in parallel, in case someone tries to build multiple
# targets, and one of them can cause a recursive target to be invoked.

# Only set this if Automake doesn't provide it.
AM_RECURSIVE_TARGETS ?= $(RECURSIVE_TARGETS:-recursive=) \
  $(RECURSIVE_CLEAN_TARGETS:-recursive=) \
  dist distcheck tags ctags

ALL_RECURSIVE_TARGETS += $(AM_RECURSIVE_TARGETS)

ifneq ($(word 2, $(MAKECMDGOALS)), )
ifneq ($(filter $(ALL_RECURSIVE_TARGETS), $(MAKECMDGOALS)), )
.NOTPARALLEL:
endif
endif