path: root/Makefile

# Copyright © Tavian Barnes <tavianator@tavianator.com>
# SPDX-License-Identifier: 0BSD

# This Makefile implements the configuration and build steps for bfs.  It is
# portable to both GNU make and the BSD make implementations (how that works
# is documented below).  To build bfs, run
#
#     $ make config
#     $ make

# The default build target
default: bfs
.PHONY: default

# BSD make will chdir into ${.OBJDIR} by default, unless we tell it not to
.OBJDIR: .

# We don't use any suffix rules
.SUFFIXES:

# GNU make has $^ for the full list of targets, while BSD make has $> and the
# long-form ${.ALLSRC}.  We could write $^ $> to get them both, but that would
# break if one of them implemented support for the other.  So instead, bring
# BSD's ${.ALLSRC} to GNU.
.ALLSRC ?= $^

# Platform detection
OS != uname
ARCH != uname -m

# For out-of-tree builds, e.g.
#
#     $ make config BUILDDIR=/path/to/build/dir
#     $ make BUILDDIR=/path/to/build/dir
BUILDDIR ?= .

# Shorthand for build subdirectories
BIN := ${BUILDDIR}/bin
GEN := ${BUILDDIR}/gen
OBJ := ${BUILDDIR}/obj

# GNU make strips a leading ./ from target names, so do the same for BSD make
BIN := ${BIN:./%=%}
GEN := ${GEN:./%=%}
OBJ := ${OBJ:./%=%}

# Installation paths
DESTDIR ?=
PREFIX ?= /usr
MANDIR ?= ${PREFIX}/share/man

# Configurable executables; can be overridden with
#
#     $ make config CC=clang
CC ?= cc
INSTALL ?= install
MKDIR ?= mkdir -p
PKG_CONFIG ?= pkg-config
RM ?= rm -f

# Configurable flags

CPPFLAGS ?=
CFLAGS ?= \
    -g \
    -Wall \
    -Wformat=2 \
    -Werror=implicit \
    -Wimplicit-fallthrough \
    -Wmissing-declarations \
    -Wshadow \
    -Wsign-compare \
    -Wstrict-prototypes
LDFLAGS ?=
LDLIBS ?=

EXTRA_CPPFLAGS ?=
EXTRA_CFLAGS ?=
EXTRA_LDFLAGS ?=
EXTRA_LDLIBS ?=

GIT_VERSION != test -d .git && command -v git >/dev/null 2>&1 && git describe --always --dirty || echo 3.1.3
VERSION ?= ${GIT_VERSION}

# Immutable flags
export BFS_CPPFLAGS= \
    -D__EXTENSIONS__ \
    -D_ATFILE_SOURCE \
    -D_BSD_SOURCE \
    -D_DARWIN_C_SOURCE \
    -D_DEFAULT_SOURCE \
    -D_GNU_SOURCE \
    -D_LARGEFILE64_SOURCE \
    -D_POSIX_PTHREAD_SEMANTICS \
    -D_FILE_OFFSET_BITS=64 \
    -D_TIME_BITS=64
export BFS_CFLAGS= -std=c17 -pthread

# Platform-specific system libraries
LDLIBS,DragonFly := -lposix1e
LDLIBS,Linux := -lrt
LDLIBS,NetBSD := -lutil
LDLIBS,SunOS := -lsocket -lnsl
_BFS_LDLIBS := ${LDLIBS,${OS}}
export BFS_LDLIBS=${_BFS_LDLIBS}

# Build profiles
ASAN ?= n
LSAN ?= n
MSAN ?= n
TSAN ?= n
UBSAN ?= n
GCOV ?= n
LINT ?= n
RELEASE ?= n

export ASAN_CFLAGS= -fsanitize=address
export LSAN_CFLAGS= -fsanitize=leak
export MSAN_CFLAGS= -fsanitize=memory -fsanitize-memory-track-origins
export UBSAN_CFLAGS= -fsanitize=undefined

# https://github.com/google/sanitizers/issues/342
export TSAN_CPPFLAGS= -DBFS_USE_TARGET_CLONES=0
export TSAN_CFLAGS= -fsanitize=thread

SAN := ${ASAN}${LSAN}${MSAN}${TSAN}${UBSAN}
export SAN_CFLAGS= -fno-sanitize-recover=all

# MSAN and TSAN both need all code to be instrumented
export NOLIBS= ${MSAN}${TSAN}

# gcov only intercepts fork()/exec() with -std=gnu*
export GCOV_CFLAGS= --coverage -std=gnu17

export LINT_CPPFLAGS= -D_FORTIFY_SOURCE=3 -DBFS_LINT
export LINT_CFLAGS= -Werror -O2

export RELEASE_CPPFLAGS= -DNDEBUG
export RELEASE_CFLAGS= -O3 -flto=auto

# Auto-detected library dependencies.  Can be set manually with
#
#     $ make config USE_LIBURING=n USE_ONIGURUMA=y
USE_LIBACL ?=
USE_LIBCAP ?=
USE_LIBSELINUX ?=
USE_LIBURING ?=
USE_ONIGURUMA ?=

# Save the new value of these variables, before they potentially get overridden
# by `-include ${CONFIG}` below

_XPREFIX := ${PREFIX}
_XMANDIR := ${MANDIR}

_XOS := ${OS}
_XARCH := ${ARCH}

_XCC := ${CC}
_XINSTALL := ${INSTALL}
_XMKDIR := ${MKDIR}
_XRM := ${RM}

_XCPPFLAGS := ${CPPFLAGS}
_XCFLAGS := ${CFLAGS}
_XLDFLAGS := ${LDFLAGS}
_XLDLIBS := ${LDLIBS}

_XUSE_LIBACL := ${USE_LIBACL}
_XUSE_LIBCAP := ${USE_LIBCAP}
_XUSE_LIBSELINUX := ${USE_LIBSELINUX}
_XUSE_LIBURING := ${USE_LIBURING}
_XUSE_ONIGURUMA := ${USE_ONIGURUMA}

# GNU make supports `export VAR`, but BSD make requires `export VAR=value`.
# Sadly, GNU make gives a recursion error on `export VAR=${VAR}`.

_BUILDDIR := ${BUILDDIR}
_PKG_CONFIG := ${PKG_CONFIG}

export BUILDDIR=${_BUILDDIR}
export PKG_CONFIG=${_PKG_CONFIG}

export XPREFIX=${_XPREFIX}
export XMANDIR=${_XMANDIR}

export XOS=${_XOS}
export XARCH=${_XARCH}

export XCC=${_XCC}
export XINSTALL=${_XINSTALL}
export XMKDIR=${_XMKDIR}
export XRM=${_XRM}

export XCPPFLAGS=${_XCPPFLAGS}
export XCFLAGS=${_XCFLAGS}
export XLDFLAGS=${_XLDFLAGS}
export XLDLIBS=${_XLDLIBS}

export XUSE_LIBACL=${_XUSE_LIBACL}
export XUSE_LIBCAP=${_XUSE_LIBCAP}
export XUSE_LIBSELINUX=${_XUSE_LIBSELINUX}
export XUSE_LIBURING=${_XUSE_LIBURING}
export XUSE_ONIGURUMA=${_XUSE_ONIGURUMA}

# The configuration file generated by `make config`
CONFIG := ${GEN}/config.mk
-include ${CONFIG}

## Configuration phase (`make config`)

# External dependencies
PKGS := \
    ${GEN}/libacl.mk \
    ${GEN}/libcap.mk \
    ${GEN}/libselinux.mk \
    ${GEN}/liburing.mk \
    ${GEN}/oniguruma.mk

# Makefile fragments generated by `make config`
MKS := \
    ${GEN}/vars.mk \
    ${GEN}/deps.mk \
    ${GEN}/objs.mk \
    ${PKGS}

# The configuration goal itself
config: ${MKS}
	@printf 'include $${GEN}/%s\n' ${MKS:${GEN}/%=%} >${CONFIG}
.PHONY: config

# Saves the configurable variables
${GEN}/vars.mk::
	@${XMKDIR} ${@D}
	@printf 'PREFIX := %s\n' "$$XPREFIX" >$@
	@printf 'MANDIR := %s\n' "$$XMANDIR" >>$@
	@printf 'OS := %s\n' "$$XOS" >>$@
	@printf 'ARCH := %s\n' "$$XARCH" >>$@
	@printf 'CC := %s\n' "$$XCC" >>$@
	@printf 'INSTALL := %s\n' "$$XINSTALL" >>$@
	@printf 'MKDIR := %s\n' "$$XMKDIR" >>$@
	@printf 'RM := %s\n' "$$XRM" >>$@
	@printf 'CPPFLAGS := %s\n' "$$BFS_CPPFLAGS" >>$@
	@test "${TSAN}" != y || printf 'CPPFLAGS += %s\n' "$$TSAN_CPPFLAGS" >>$@
	@test "${LINT}" != y || printf 'CPPFLAGS += %s\n' "$$LINT_CPPFLAGS" >>$@
	@test "${RELEASE}" != y || printf 'CPPFLAGS += %s\n' "$$RELEASE_CPPFLAGS" >>$@
	@test -z "$$XCPPFLAGS" || printf 'CPPFLAGS += %s\n' "$$XCPPFLAGS" >>$@
	@test -z "$$EXTRA_CPPFLAGS" || printf 'CPPFLAGS += %s\n' "$$EXTRA_CPPFLAGS" >>$@
	@printf 'CFLAGS := %s\n' "$$BFS_CFLAGS" >>$@
	@test "${ASAN}" != y || printf 'CFLAGS += %s\n' "$$ASAN_CFLAGS" >>$@
	@test "${LSAN}" != y || printf 'CFLAGS += %s\n' "$$LSAN_CFLAGS" >>$@
	@test "${MSAN}" != y || printf 'CFLAGS += %s\n' "$$MSAN_CFLAGS" >>$@
	@test "${TSAN}" != y || printf 'CFLAGS += %s\n' "$$TSAN_CFLAGS" >>$@
	@test "${UBSAN}" != y || printf 'CFLAGS += %s\n' "$$UBSAN_CFLAGS" >>$@
	@case "${SAN}" in *y*) printf 'CFLAGS += %s\n' "$$SAN_CFLAGS" >>$@ ;; esac
	@test "${GCOV}" != y || printf 'CFLAGS += %s\n' "$$GCOV_CFLAGS" >>$@
	@test "${LINT}" != y || printf 'CFLAGS += %s\n' "$$LINT_CFLAGS" >>$@
	@test "${RELEASE}" != y || printf 'CFLAGS += %s\n' "$$RELEASE_CFLAGS" >>$@
	@test -z "$$XCFLAGS" || printf 'CFLAGS += %s\n' "$$XCFLAGS" >>$@
	@test -z "$$EXTRA_CFLAGS" || printf 'CFLAGS += %s\n' "$$EXTRA_CFLAGS" >>$@
	@printf 'LDFLAGS := %s\n' "$$XLDFLAGS" >>$@
	@test -z "$$EXTRA_LDFLAGS" || printf 'LDFLAGS += %s\n' "$$EXTRA_LDFLAGS" >>$@
	@printf 'LDLIBS := %s\n' "$$XLDLIBS" >>$@
	@test -z "$$EXTRA_LDLIBS" || printf 'LDLIBS += %s\n' "$$EXTRA_LDLIBS" >>$@
	@test -z "$$BFS_LDLIBS" || printf 'LDLIBS += %s\n' "$$BFS_LDLIBS" >>$@
	@case "${OS}-${SAN}" in FreeBSD-*y*) printf 'POSTLINK = elfctl -e +noaslr $$@\n' >>$@ ;; esac