common.mk

# `make` with no arguments executes the first rule in the file.
.PHONY: install
install:

# Clear implicit suffix rules
.SUFFIXES:

# Homebrew, `mkdir -p` aren't safe to run in parallel
.NOTPARALLEL:

MAKEFLAGS = Lr
# -L = check symlinks' mtime and not their destinations'
# -r = don't use implicit rules
GNUMAKEFLAGS = --output-sync

# XDG base directories
XDG_CONFIG_HOME ?= $(wildcard ~/.config)
XDG_DATA_HOME   ?= $(wildcard ~/.local/share)
XDG_CACHE_HOME  ?= $(wildcard ~/.cache)
XDG_STATE_HOME  ?= $(wildcard ~/.local/state)
XDG_BIN_HOME    ?= $(abspath $(wildcard $(XDG_DATA_HOME)/../bin))

# Installation directories
prefix      ?= $(HOME)
exec_prefix ?= $(prefix)
bindir      ?= $(XDG_BIN_HOME)
datarootdir ?= $(XDG_DATA_HOME)
datadir     ?= $(datarootdir)
libdir      ?= $(exec_prefix)/lib
sbindir     ?= $(exec_prefix)/sbin
sysconfdir  ?= $(prefix)/etc

# Other important directories
GIT_STAGING := $(wildcard ~/src/github.com)

# Use Homebrew tools on macOS
OS = $(shell uname -s)
ifeq ($(OS),Darwin)
ifeq ($(shell command -v brew),/usr/local/bin/brew)
SHELL := /usr/local/bin/bash
GNUBIN := /usr/local/opt/coreutils/libexec/gnubin
else
SHELL := /bin/bash
GNUBIN := /usr/bin
endif
else
SHELL := /bin/bash
GNUBIN := /usr/bin
endif

# Every Makefile should define the variable INSTALL, which is the basic command
# for installing a file into the system.
INSTALL := $(GNUBIN)/install

# Every Makefile should also define the variables INSTALL_PROGRAM and
# INSTALL_DATA. Then it should use those variables as the commands for actual
# installation, for executables and non-executables respectively.
INSTALL_PROGRAM := $(INSTALL) -D --compare
INSTALL_DATA := $(INSTALL) -D --compare -m 644

# Additional commands
MKDIR := $(GNUBIN)/mkdir -p
LN := $(GNUBIN)/ln -s -r -f