Add python support, better build system

.gitmodules

@@ -1,3 +1,6 @@
 [submodule "llvm"]
 	path = llvm
 	url = https://github.com/llvm/llvm-project.git
+[submodule "cpython"]
+	path = cpython
+	url = https://github.com/python/cpython.git

Makefile

@@ -0,0 +1,61 @@
+WASI_SDK_PREFIX ?= /opt/wasi-sdk/
+PYTHON ?= /usr/bin/env python3
+DIR := $(shell pwd)
+WASMTIME ?= $(shell which wasmtime)
+WASMTIME_FLAGS ?= --wasm max-wasm-stack=8388608 --dir {HOST_DIR}::{GUEST_DIR} \
+	--env {ENV_VAR_NAME}={ENV_VAR_VALUE} {PYTHON_WASM}
+
+.PHONY:
+all: test build/output.tar.br
+
+build/output.tar.br: build/output/python build/output/cpp
+	tar c -C build/output . | brotli --large_window=30 > $@
+
+build/output/python:
+	rm -rf "$@"
+	${PYTHON} cpython/Tools/wasm/wasi.py build \
+		--host-runner="${WASMTIME} run ${WASMTIME_FLAGS}" -- \
+		--prefix="${DIR}/$@" --exec-prefix="${DIR}/$@" \
+		--disable-test-modules
+	make -C cpython/cross-build/wasm32-wasi install
+
+build/libwasishim.a: wasi_shim.cpp
+	${WASI_SDK_PREFIX}/bin/clang++ -fno-exceptions -std=c++20 $< -O3 -c -o $@
+
+build/llvm-sources: llvm.patch
+	rm -rf "$@"
+	cp -r llvm "$@"
+	cd "$@" && patch -p1 < ${DIR}/llvm.patch
+
+build/llvm-build: build/llvm-sources build/libwasishim.a
+	cmake -B build/llvm-build build/llvm-sources/llvm \
+		-G Ninja -DCMAKE_BUILD_TYPE=Release \
+		-DWASI_SDK_PREFIX=${WASI_SDK_PREFIX} \
+		-DCMAKE_TOOLCHAIN_FILE=${WASI_SDK_PREFIX}/share/cmake/wasi-sdk.cmake \
+		-DLLVM_TARGETS_TO_BUILD=WebAssembly -DLLVM_ENABLE_PROJECTS="clang;lld" \
+		-DLLVM_ENABLE_THREADS=OFF -DLLVM_INCLUDE_BENCHMARKS=OFF \
+		-DLLVM_DEFAULT_TARGET_TRIPLE=wasm32-wasi -DCMAKE_MODULE_PATH=${DIR}/cmake \
+		-DCMAKE_CXX_FLAGS="-I${DIR} -fno-exceptions" -DLLVM_INCLUDE_TESTS=OFF \
+		-DLLVM_BUILD_LLVM_DYLIB=OFF -DLLVM_INCLUDE_EXAMPLES=OFF -DLLVM_ENABLE_PIC=OFF \
+		-DLLVM_INCLUDE_UTILS=OFF -DLLVM_BUILD_UTILS=OFF -DLLVM_ENABLE_PLUGINS=OFF \
+		-DCLANG_PLUGIN_SUPPORT=OFF \
+		-DCMAKE_EXE_LINKER_FLAGS="-Wl,-z -Wl,stack-size=1048576 -lwasishim -L${DIR}/build"
+	ninja -C build/llvm-build
+
+
+build/output/cpp: build/llvm-build
+	rm -rf "$@"
+	mkdir -p $@/root
+	cp -Lr ${WASI_SDK_PREFIX}/share/wasi-sysroot/* $@/root/
+	cp -L ${WASI_SDK_PREFIX}/lib/clang/*/lib/wasi/libclang_rt.* $@/root/lib/wasm32-wasi/
+	rm -rf $@/root/share/wasm32-wasi-threads $@/root/lib/wasm32-wasi-threads
+	cp -Lr $</lib/clang/18/include $@/root/clang-include
+	cp -Lr $</bin/clang-18 $@/clang
+	cp -Lr $</bin/lld $@/wasm-ld
+
+.PHONY:
+test: | build/output/python build/output/cpp
+	./test.sh
+
+clean:
+	rm -rf build/ cpython/cross-build

test.sh

@@ -2,11 +2,17 @@
 
 set -xe
 
-DIR=build/fs
+DIR=build/test
+
+$(which wasmtime) run --dir $PWD/build/output/python::/ \
+  --env PYTHONPATH=/lib/python-3.13 \
+  $PWD/build/output/python/bin/python3.wasm \
+  -c "import json; print(json.dumps('hello'))"
 
 rm -rf $DIR
 mkdir -p $DIR
-brotli -d --stdout build/output.tar.br | tar x -C $DIR
+cp -r build/output/cpp/* $DIR
+
 cat > $DIR/root/main.cc << EOF
 #include <stdio.h>
 #include <string>