# Any copyright is dedicated to the Public Domain.
# http://creativecommons.org/publicdomain/zero/1.0/

ROOT_DIR=${CURDIR}
LLVM_PROJ_DIR?=$(ROOT_DIR)/src/llvm-project
VERSION_SCRIPT=python3 ./version.py

# Windows needs munging
ifeq ($(OS),Windows_NT)

PREFIX?=c:/wasi-sdk
# we need to explicitly call bash -c for makefile $(shell ...), otherwise we'll try under
# who knows what
BASH=bash -c

ifeq (x$(MSYSTEM),x)
$(error On Windows, this Makefile only works in MSYS2 environments such as git-bash.)
endif

# msys needs any /-prefixed arguments, or =/ containing, to turn into //
# because it tries to path-expand the / into the msys root.  // escapes this.
ESCAPE_SLASH=/

BUILD_PREFIX=$(PREFIX)

# assuming we're running under msys2 (git-bash), PATH needs /c/foo format directories (because
# it itself is :-delimited)
PATH_PREFIX=$(shell cygpath.exe -u $(BUILD_PREFIX))

else

PREFIX?=/opt/wasi-sdk
DESTDIR=$(abspath build/install)
BUILD_PREFIX=$(DESTDIR)$(PREFIX)
PATH_PREFIX=$(BUILD_PREFIX)
ESCAPE_SLASH?=
BASH=

endif

ifeq ($(shell uname),Darwin)
override LLVM_CMAKE_FLAGS += -DCMAKE_OSX_ARCHITECTURES="arm64;x86_64" \
		    -DCMAKE_OSX_DEPLOYMENT_TARGET=10.12
endif

TARGETS = wasm32-wasi wasm32-wasip1 wasm32-wasip2 wasm32-wasip1-threads wasm32-wasi-threads

# Only the major version is needed for Clang, see https://reviews.llvm.org/D125860.
CLANG_VERSION=$(shell $(VERSION_SCRIPT) llvm-major --llvm-dir=$(LLVM_PROJ_DIR))
VERSION:=$(shell $(VERSION_SCRIPT))
DEBUG_PREFIX_MAP=-fdebug-prefix-map=$(ROOT_DIR)=wasisdk://v$(VERSION)

default: build
	@echo "Use -fdebug-prefix-map=$(ROOT_DIR)=wasisdk://v$(VERSION)"

check:
	TARGETS="$(TARGETS)" tests/run.sh "$(BUILD_PREFIX)" "$(RUNTIME)"

clean:
	rm -rf build $(DESTDIR)

# Default symlinks that clang creates to the `clang` executable
CLANG_LINKS_TO_CREATE = clang++ clang-cl clang-cpp

# Add target-prefixed versions of `clang` and `clang++` so they can be used
# without `--target` as it's auto-inferred from the executable name by clang.
CLANG_LINKS_TO_CREATE += $(foreach target,$(TARGETS),$(target)-clang)
CLANG_LINKS_TO_CREATE += $(foreach target,$(TARGETS),$(target)-clang++)

# Small helper to create a `join-with` function that can join elements of a
# list with a defined separator.
noop =
space = $(noop) $(noop)
join-with = $(subst $(space),$1,$(strip $2))

build/llvm.BUILT:
	mkdir -p build/llvm
	cd build/llvm && cmake -G Ninja \
		-DCLANG_LINKS_TO_CREATE="$(call join-with,;,$(CLANG_LINKS_TO_CREATE))" \
		-DCMAKE_BUILD_TYPE=MinSizeRel \
		-DLLVM_ENABLE_TERMINFO=OFF \
		-DLLVM_ENABLE_ZLIB=OFF \
		-DLLVM_ENABLE_ZSTD=OFF \
		-DLLVM_STATIC_LINK_CXX_STDLIB=ON \
		-DCMAKE_INSTALL_PREFIX=$(PREFIX) \
		-DLLVM_INCLUDE_TESTS=OFF \
		-DLLVM_INCLUDE_UTILS=OFF \
		-DLLVM_INCLUDE_BENCHMARKS=OFF \
		-DLLVM_INCLUDE_EXAMPLES=OFF \
		-DLLVM_TARGETS_TO_BUILD=WebAssembly \
		-DLLVM_DEFAULT_TARGET_TRIPLE=wasm32-wasi \
		-DLLVM_ENABLE_PROJECTS="lld;clang;clang-tools-extra" \
		$(if $(patsubst 9,,$(CLANG_VERSION)), \
	             $(if $(patsubst 10,,$(CLANG_VERSION)), \
		          -DDEFAULT_SYSROOT=../share/wasi-sysroot, \
			  -DDEFAULT_SYSROOT=$(PREFIX)/share/wasi-sysroot), \
		     -DDEFAULT_SYSROOT=$(PREFIX)/share/wasi-sysroot) \
		-DLLVM_INSTALL_BINUTILS_SYMLINKS=TRUE \
		-DLLVM_ENABLE_LIBXML2=OFF \
		$(LLVM_CMAKE_FLAGS) \
		$(LLVM_PROJ_DIR)/llvm
	DESTDIR=$(DESTDIR) ninja $(NINJA_FLAGS) -C build/llvm \
		install-clang \
		install-clang-format \
		install-clang-tidy \
		install-clang-apply-replacements \
		install-lld \
		install-llvm-mc \
		install-llvm-ranlib \
		install-llvm-strip \
		install-llvm-dwarfdump \
		install-clang-resource-headers \
		install-ar \
		install-ranlib \
		install-strip \
		install-nm \
		install-size \
		install-strings \
		install-objdump \
		install-objcopy \
		install-c++filt \
		llvm-config
	touch build/llvm.BUILT

# Build the `wasm-component-ld` linker from source via `cargo install`. This is
# used for the `wasm32-wasip2` target natively by Clang. Note that `--root`
# passed to `cargo install` will place it in the output directory automatically.
build/wasm-component-ld.BUILT: build/llvm.BUILT
	cargo install wasm-component-ld@0.1.5 --root $(BUILD_PREFIX)
	touch build/wasm-component-ld.BUILT


# Flags for running `make` in wasi-libc
# $(1): the target that's being built
WASI_LIBC_MAKEFLAGS = \
	-C $(ROOT_DIR)/src/wasi-libc \
	CC=$(BUILD_PREFIX)/bin/clang \
	AR=$(BUILD_PREFIX)/bin/llvm-ar \
	NM=$(BUILD_PREFIX)/bin/llvm-nm \
	SYSROOT=$(BUILD_PREFIX)/share/wasi-sysroot \
	TARGET_TRIPLE=$(1)

build/wasi-libc.BUILT: build/compiler-rt.BUILT build/wasm-component-ld.BUILT
	$(MAKE) $(call WASI_LIBC_MAKEFLAGS,wasm32-wasi) default libc_so
	$(MAKE) $(call WASI_LIBC_MAKEFLAGS,wasm32-wasip1) default libc_so
	$(MAKE) $(call WASI_LIBC_MAKEFLAGS,wasm32-wasip2) WASI_SNAPSHOT=p2 default libc_so
	$(MAKE) $(call WASI_LIBC_MAKEFLAGS,wasm32-wasi-threads) THREAD_MODEL=posix
	$(MAKE) $(call WASI_LIBC_MAKEFLAGS,wasm32-wasip1-threads) THREAD_MODEL=posix
	touch build/wasi-libc.BUILT

build/compiler-rt.BUILT: build/llvm.BUILT
	# Do the build, and install it.
	mkdir -p build/compiler-rt
	cd build/compiler-rt && cmake -G Ninja \
		-DCMAKE_SYSROOT=$(BUILD_PREFIX)/share/wasi-sysroot \
		-DCMAKE_C_COMPILER_WORKS=ON \
		-DCMAKE_CXX_COMPILER_WORKS=ON \
		-DCMAKE_AR=$(BUILD_PREFIX)/bin/ar \
		-DCMAKE_MODULE_PATH=$(ROOT_DIR)/cmake \
		-DCMAKE_BUILD_TYPE=RelWithDebInfo \
		-DCMAKE_TOOLCHAIN_FILE=$(ROOT_DIR)/wasi-sdk.cmake \
		-DCOMPILER_RT_BAREMETAL_BUILD=On \
		-DCOMPILER_RT_BUILD_XRAY=OFF \
		-DCOMPILER_RT_INCLUDE_TESTS=OFF \
		-DCOMPILER_RT_HAS_FPIC_FLAG=OFF \
		-DCOMPILER_RT_ENABLE_IOS=OFF \
		-DCOMPILER_RT_DEFAULT_TARGET_ONLY=On \
		-DWASI_SDK_PREFIX=$(BUILD_PREFIX) \
		-DCMAKE_C_FLAGS="$(DEBUG_PREFIX_MAP)" \
		-DLLVM_CONFIG_PATH=$(ROOT_DIR)/build/llvm/bin/llvm-config \
		-DCOMPILER_RT_OS_DIR=wasi \
		-DCMAKE_INSTALL_PREFIX=$(PREFIX)/lib/clang/$(CLANG_VERSION)/ \
		-DCMAKE_VERBOSE_MAKEFILE:BOOL=ON \
		$(LLVM_PROJ_DIR)/compiler-rt/lib/builtins
	DESTDIR=$(DESTDIR) ninja $(NINJA_FLAGS) -C build/compiler-rt install
	# Install clang-provided headers.
	cp -R $(ROOT_DIR)/build/llvm/lib/clang $(BUILD_PREFIX)/lib/
	cp -R $(BUILD_PREFIX)/lib/clang/$(CLANG_VERSION)/lib/wasi $(BUILD_PREFIX)/lib/clang/$(CLANG_VERSION)/lib/wasip1
	cp -R $(BUILD_PREFIX)/lib/clang/$(CLANG_VERSION)/lib/wasi $(BUILD_PREFIX)/lib/clang/$(CLANG_VERSION)/lib/wasip2
	touch build/compiler-rt.BUILT

# Flags for libcxx and libcxxabi.
# $(1): pthreads ON or OFF
# $(2): shared libraries ON or OFF
# $(3): the name of the target being built for
# $(4): extra compiler flags to pass
LIBCXX_CMAKE_FLAGS = \
    -DCMAKE_C_COMPILER_WORKS=ON \
    -DCMAKE_CXX_COMPILER_WORKS=ON \
    -DCMAKE_AR=$(BUILD_PREFIX)/bin/ar \
    -DCMAKE_MODULE_PATH=$(ROOT_DIR)/cmake \
    -DCMAKE_TOOLCHAIN_FILE=$(ROOT_DIR)/wasi-sdk.cmake \
    -DCMAKE_STAGING_PREFIX=$(PREFIX)/share/wasi-sysroot \
    -DCMAKE_POSITION_INDEPENDENT_CODE=$(2) \
    -DLLVM_CONFIG_PATH=$(ROOT_DIR)/build/llvm/bin/llvm-config \
    -DCMAKE_VERBOSE_MAKEFILE:BOOL=ON \
    -DCXX_SUPPORTS_CXX11=ON \
    -DLIBCXX_ENABLE_THREADS:BOOL=$(1) \
    -DLIBCXX_HAS_PTHREAD_API:BOOL=$(1) \
    -DLIBCXX_HAS_EXTERNAL_THREAD_API:BOOL=OFF \
    -DLIBCXX_BUILD_EXTERNAL_THREAD_LIBRARY:BOOL=OFF \
    -DLIBCXX_HAS_WIN32_THREAD_API:BOOL=OFF \
    -DLLVM_COMPILER_CHECKED=ON \
    -DCMAKE_BUILD_TYPE=RelWithDebInfo \
    -DLIBCXX_ENABLE_SHARED:BOOL=$(2) \
    -DLIBCXX_ENABLE_EXPERIMENTAL_LIBRARY:BOOL=OFF \
    -DLIBCXX_ENABLE_EXCEPTIONS:BOOL=OFF \
    -DLIBCXX_ENABLE_FILESYSTEM:BOOL=ON \
    -DLIBCXX_ENABLE_ABI_LINKER_SCRIPT:BOOL=OFF \
    -DLIBCXX_CXX_ABI=libcxxabi \
    -DLIBCXX_CXX_ABI_INCLUDE_PATHS=$(LLVM_PROJ_DIR)/libcxxabi/include \
    -DLIBCXX_HAS_MUSL_LIBC:BOOL=ON \
    -DLIBCXX_ABI_VERSION=2 \
    -DLIBCXXABI_ENABLE_EXCEPTIONS:BOOL=OFF \
    -DLIBCXXABI_ENABLE_SHARED:BOOL=$(2) \
    -DLIBCXXABI_SILENT_TERMINATE:BOOL=ON \
    -DLIBCXXABI_ENABLE_THREADS:BOOL=$(1) \
    -DLIBCXXABI_HAS_PTHREAD_API:BOOL=$(1) \
    -DLIBCXXABI_HAS_EXTERNAL_THREAD_API:BOOL=OFF \
    -DLIBCXXABI_BUILD_EXTERNAL_THREAD_LIBRARY:BOOL=OFF \
    -DLIBCXXABI_HAS_WIN32_THREAD_API:BOOL=OFF \
    -DLIBCXXABI_ENABLE_PIC:BOOL=$(2) \
    -DLIBCXXABI_USE_LLVM_UNWINDER:BOOL=OFF \
    -DWASI_SDK_PREFIX=$(BUILD_PREFIX) \
    -DUNIX:BOOL=ON \
    --debug-trycompile \
    -DCMAKE_SYSROOT=$(BUILD_PREFIX)/share/wasi-sysroot \
    -DCMAKE_C_FLAGS="$(DEBUG_PREFIX_MAP) $(EXTRA_CFLAGS) $(4) --target=$(3)" \
    -DCMAKE_CXX_FLAGS="$(DEBUG_PREFIX_MAP) $(EXTRA_CXXFLAGS) $(4) --target=$(3)" \
    -DLIBCXX_LIBDIR_SUFFIX=$(ESCAPE_SLASH)/$(3) \
    -DLIBCXXABI_LIBDIR_SUFFIX=$(ESCAPE_SLASH)/$(3) \
    -DLLVM_ENABLE_RUNTIMES="libcxx;libcxxabi" \
    $(LLVM_PROJ_DIR)/runtimes

# Rules to build libcxx, factored out here to deduplicate the below
# $(1): pthreads ON or OFF
# $(2): shared libraries ON or OFF
# $(3): the name of the target being built for
define BUILD_LIBCXX
	mkdir -p build/libcxx-$(3)
	cd build/libcxx-$(3) && cmake -G Ninja $(call LIBCXX_CMAKE_FLAGS,$(1),$(2),$(3),$(4))
	ninja $(NINJA_FLAGS) -C build/libcxx-$(3)
	DESTDIR=$(DESTDIR) ninja $(NINJA_FLAGS) -C build/libcxx-$(3) install
	rm -rf $(BUILD_PREFIX)/share/wasi-sysroot/include/$(3)/c++
	mv $(BUILD_PREFIX)/share/wasi-sysroot/include/c++ $(BUILD_PREFIX)/share/wasi-sysroot/include/$(3)/
endef

build/libcxx.BUILT: build/llvm.BUILT build/wasi-libc.BUILT
	$(call BUILD_LIBCXX,OFF,ON,wasm32-wasi)
	$(call BUILD_LIBCXX,OFF,ON,wasm32-wasip1)
	$(call BUILD_LIBCXX,OFF,ON,wasm32-wasip2)
	$(call BUILD_LIBCXX,ON,OFF,wasm32-wasi-threads,-pthread)
	$(call BUILD_LIBCXX,ON,OFF,wasm32-wasip1-threads,-pthread)
	# As of this writing, `clang++` will ignore the above include dirs unless this one also exists:
	mkdir -p $(BUILD_PREFIX)/share/wasi-sysroot/include/c++/v1
	touch build/libcxx.BUILT

build/config.BUILT:
	mkdir -p $(BUILD_PREFIX)/share/misc
	cp src/config/config.sub src/config/config.guess $(BUILD_PREFIX)/share/misc
	mkdir -p $(BUILD_PREFIX)/share/cmake/Platform
	cp wasi-sdk.cmake $(BUILD_PREFIX)/share/cmake
	cp wasi-sdk-pthread.cmake $(BUILD_PREFIX)/share/cmake
	cp cmake/Platform/WASI.cmake $(BUILD_PREFIX)/share/cmake/Platform
	touch build/config.BUILT

build/version.BUILT:
	$(VERSION_SCRIPT) dump > $(BUILD_PREFIX)/VERSION
	touch build/version.BUILT

build: build/llvm.BUILT build/wasi-libc.BUILT build/compiler-rt.BUILT build/libcxx.BUILT build/config.BUILT build/version.BUILT

strip: build/llvm.BUILT
	./strip_symbols.sh $(BUILD_PREFIX)/bin

package: build/package.BUILT

build/package.BUILT: build strip
	mkdir -p dist
	./deb_from_installation.sh $(shell pwd)/dist "$(VERSION)" "$(BUILD_PREFIX)"
	./tar_from_installation.sh "$(shell pwd)/dist" "$(VERSION)" "$(BUILD_PREFIX)"
	touch build/package.BUILT

.PHONY: default clean build strip package check