# based on https://make.mad-scientist.net/papers/multi-architecture-builds/

_libc := $(if $(LIBC),$(LIBC),gnu)
ifeq (,$(filter gnu musl,$(_libc)))
  _link_type := $(error "LIBC has to be set to one of: gnu, musl")
endif

_link_type := $(if $(LINK),$(LINK),dynamic)
ifeq (,$(filter dynamic static,$(_link_type)))
  _link_type := $(error "LINK has to be set to one of: dynamic, static")
endif

_profile := $(if $(PROFILE),$(PROFILE),release)
ifeq (,$(filter release debug size_optimized,$(_profile)))
  _profile := $(error "PROFILE has to be set to one of: debug, release, size_optimized")
endif

ARCH ?= $(shell uname -m)
RUST_TARGET := $(ARCH)-unknown-linux-$(_libc)

#----- Begin Boilerplate
ifeq (,$(filter _out_%,$(notdir $(CURDIR))))
  include target.mk
else
#----- End Boilerplate

VPATH = $(SRCDIR)

CARGO ?= cargo
STRIP ?= strip
CC ?= gcc

FEATURES := ""#"env_logger"

THIS_DIR := $(dir $(realpath $(lastword $(MAKEFILE_LIST))))
REPO_ROOT := $(realpath $(THIS_DIR)/..)
CARGO_OBJDIR := cargo/$(RUST_TARGET)/$(_profile)

_rust_cli_profile := $(if $(filter $(_profile),debug),dev,$(_profile))

# TODO: `make LINK=static` fails with linker error "undefined reference to `_dl_find_object'" in libgcc_eh.a

STRIPFLAGS += -s --strip-unneeded -R .comment -R .gnu.version -R .note -R .note.gnu.build-id -R .note.ABI-tag
STATIC_LINK_LIBS += -lservicepoint_binding_c

size_optimized_CARGOFLAGS += -Zbuild-std="core,std,alloc,proc_macro,panic_abort" \
	-Zbuild-std-features="panic_immediate_abort"
CARGOFLAGS += --manifest-path=$(REPO_ROOT)/Cargo.toml \
	--profile=$(_rust_cli_profile) \
	--no-default-features \
	--features=$(FEATURES) \
	--target=$(RUST_TARGET) \
	$($(_profile)_CARGOFLAGS) \
	--target-dir=cargo

CFLAGS += -Wall -Wextra -pedantic -fwhole-program -fPIE -pie
_no_debug_cflags := -ffunction-sections -fdata-sections -Wl,--gc-sections
size_optimized_CFLAGS += -Oz \
	-fwrapv -fomit-frame-pointer -fno-stack-protector \
	-fno-unroll-loops \
	-fno-unwind-tables -fno-asynchronous-unwind-tables \
	-fmerge-all-constants \
	-Wl,-z,norelro \
	-Wl,--hash-style=gnu \
	-fvisibility=hidden \
	-Bsymbolic \
	-Wl,--exclude-libs,ALL \
	-fno-ident \
	-fno-exceptions \
	$(_no_debug_cflags)

release_CFLAGS += -O2 \
	$(_no_debug_cflags)
debug_CFLAGS += -Og
static_CFLAGS += -static $(STATIC_LINK_LIBS)
dynamic_CFLAGS += -Wl,-Bstatic $(STATIC_LINK_LIBS) -Wl,-Bdynamic

_servicepoint_cflags := -I $(REPO_ROOT)/include -L $(CARGO_OBJDIR)
CFLAGS += $($(_libc)_CFLAGS) $($(_profile)_CFLAGS) $($(_link_type)_CFLAGS) $(_servicepoint_cflags)
ifeq ($(LTO), 1)
	CFLAGS += -flto
endif

size_optimized_RUSTFLAGS += -Zlocation-detail=none \
	-Zfmt-debug=none \
	-C link-arg=-z,norelro \
	-C panic=abort \
	-C link-arg=-Wl,--hash-style=gnu
static_RUSTFLAGS += --crate-type=staticlib -Ctarget-feature=+crt-static

RUSTFLAGS += $($(_libc)_RUSTFLAGS) $($(_profile)_RUSTFLAGS) $($(_link_type)_RUSTFLAGS)
ifneq ($(_profile), debug)
	RUSTFLAGS += -C link-arg=-s -C link-arg=-Wl,--gc-sections
endif

# ADD NEW EXAMPLES HERE
_c_src := src/announce.c src/brightness_tester.c src/header_logger.c \
	src/moving_line.c src/random_stuff.c src/wiping_clear.c
_programs := $(basename $(notdir $(_c_src)))
_bins := $(_programs)
_unstripped_bins := $(addsuffix _unstripped, $(_bins))

.SUFFIXES:

.PHONY: all build-rust

all: $(_bins)

$(_unstripped_bins): %_unstripped: src/%.c src/helpers.h build-rust
	$(CC) $< $(CFLAGS) -o $@

$(_bins): %: %_unstripped
	$(STRIP) $(STRIPFLAGS) $^ -o $@

build-rust:
	# generate servicepoint header and library to link against
	$(CARGO) rustc $(CARGOFLAGS) -- $(RUSTFLAGS)

#----- Begin Boilerplate
endif