.PHONY: all
all: test.wasm

# build llvm and clang (for wasm only)
toolchain/build/llvm/bin/clang:
	mkdir -p toolchain/build/llvm
	cmake -G "Unix Makefiles" \
		-DLLVM_TARGETS_TO_BUILD= \
		-DLLVM_EXPERIMENTAL_TARGETS_TO_BUILD=WebAssembly \
		-S toolchain/src/llvm -B toolchain/build/llvm
	# install the tools we need
	$(MAKE) -C toolchain/build/llvm clang lld llvm-ar llvm-config llvm-ranlib

ROOT_DIR=${CURDIR}
# now build libc
sysroot/lib/libc.a: toolchain/build/llvm/bin/clang
	mkdir -p toolchain/build/musl
	cd toolchain/build/musl; $(ROOT_DIR)/toolchain/src/musl/configure \
		CC=$(ROOT_DIR)/toolchain/build/llvm/bin/clang \
		CFLAGS="--target=wasm32-unknown-unknown-wasm -O3" \
		--prefix=$(ROOT_DIR)/sysroot \
		wasm32
	$(MAKE) -C toolchain/build/musl install \
		CROSS_COMPILE=$(ROOT_DIR)/toolchain/build/llvm/bin/llvm-
	# need to copy over musl's list of javascript function imports
	cp toolchain/src/musl/arch/wasm32/libc.imports sysroot/lib

# build the wasm32 builtins
toolchain/build/llvm/lib/clang/8.0.0/lib/libclang_rt.builtins-wasm32.a: toolchain/build/llvm/bin/clang
	mkdir -p toolchain/build/compiler-rt
	cmake -G "Unix Makefiles" \
		-DCMAKE_TOOLCHAIN_FILE=$(ROOT_DIR)/toolchain/compiler-rt.cmake \
		-S toolchain/src/compiler-rt/lib/builtins -B toolchain/build/compiler-rt
	$(MAKE) -C toolchain/build/compiler-rt/ install

sysroot/lib/libc++.a: toolchain/build/llvm/bin/clang toolchain/build/llvm/lib/clang/8.0.0/lib/libclang_rt.builtins-wasm32.a sysroot/lib/libc.a
	mkdir -p toolchain/build/libcxx
	cmake -G "Unix Makefiles" \
		-DCMAKE_TOOLCHAIN_FILE=$(ROOT_DIR)/toolchain/libcxx.cmake \
		-S toolchain/src/libcxx/ -B toolchain/build/libcxx
	$(MAKE) -C toolchain/build/libcxx install

sysroot/lib/libc++abi.a: toolchain/build/llvm/bin/clang sysroot/lib/libc++.a
	mkdir -p toolchain/build/libcxxabi
	cmake -G "Unix Makefiles" \
		-DCMAKE_TOOLCHAIN_FILE=$(ROOT_DIR)/toolchain/libcxxabi.cmake \
		-S toolchain/src/libcxxabi -B toolchain/build/libcxxabi
	$(MAKE) -C toolchain/build/libcxxabi install


sysroot: sysroot/lib/libc.a sysroot/lib/libc++.a sysroot/lib/libc++abi.a

test.wasm: test.cpp sysroot
	toolchain/build/llvm/bin/clang++ \
		--target=wasm32-unknown-unknown-wasm -g -O3 \
		-fno-exceptions --sysroot=sysroot -nostartfiles \
		-I/usr/local/include \
	   	-Wl,--export=setup,--export=update,--demangle,--no-entry,--allow-undefined-file=gles2.imports \
		test.cpp -o test.wasm