Port MicroQuickJS to WASI 0.2 Component

.gitignore

@@ -0,0 +1,20 @@
+build/
+generated/
+mquickjs_build_native
+mquickjs_atom.h
+mqjs_stdlib.h
+*.o
+*.d
+*.wasm
+*.host.o
+/wasi_snapshot_preview1.reactor.wasm
+/output.txt
+mqjs
+example
+example_stdlib
+mqjs_stdlib
+mquickjs_build
+mquickjs_build_atoms
+test_builtin.bin
+dtoa_test
+libm_test

.gitmodules

@@ -0,0 +1,6 @@
+[submodule "packages/wasi-sdk"]
+	path = packages/wasi-sdk
+	url = https://github.com/WebAssembly/wasi-sdk
+[submodule "packages/wasmedge"]
+	path = packages/wasmedge
+	url = https://github.com/WasmEdge/WasmEdge

Makefile.wasi

@@ -0,0 +1,76 @@
+WASI_SDK_PATH ?= /opt/wasi-sdk
+CC = $(WASI_SDK_PATH)/bin/clang
+ADAPTER ?= wasi_snapshot_preview1.reactor.wasm
+
+# -mexec-model is only valid for linking, not compilation
+CFLAGS = -Oz -D_WASI_EMULATED_SIGNAL -D_WASI_EMULATED_PROCESS_CLOCKS \
+         -Werror=implicit-function-declaration -fno-math-errno -fno-trapping-math \
+         --target=wasm32-wasi -mllvm -wasm-enable-sjlj
+
+LDFLAGS = --target=wasm32-wasi -mexec-model=reactor \
+          -Wl,--no-entry -Wl,--export=cabi_realloc -Wl,--export=__wasm_call_ctors \
+          -lwasi-emulated-signal -lwasi-emulated-process-clocks -lsetjmp -lm
+
+BUILD_DIR = build
+GEN_DIR = generated
+
+OBJS = $(BUILD_DIR)/mquickjs.o $(BUILD_DIR)/cutils.o $(BUILD_DIR)/dtoa.o $(BUILD_DIR)/libm.o \
+       $(BUILD_DIR)/microquickjs.o $(BUILD_DIR)/glue.o $(BUILD_DIR)/wasi_preview1_stubs.o
+
+all: $(BUILD_DIR)/microquickjs.component.wasm
+
+$(BUILD_DIR):
+	mkdir -p $(BUILD_DIR)
+
+# Native build tool to generate stdlib headers
+mquickjs_build_native: mquickjs_build.c mqjs_stdlib.c cutils.c
+	gcc -O2 -Wall -I. $^ -o $@ -lm
+
+$(BUILD_DIR)/mquickjs_atom.h: mquickjs_build_native | $(BUILD_DIR)
+	./mquickjs_build_native -a -m32 > $@
+
+$(BUILD_DIR)/mqjs_stdlib.h: mquickjs_build_native | $(BUILD_DIR)
+	./mquickjs_build_native -m32 > $@
+
+headers: $(BUILD_DIR)/mquickjs_atom.h $(BUILD_DIR)/mqjs_stdlib.h
+
+# wit-bindgen code generation
+$(GEN_DIR)/microquickjs.c $(GEN_DIR)/microquickjs.h: microquickjs.wit
+	mkdir -p $(GEN_DIR)
+	wit-bindgen c microquickjs.wit --out-dir $(GEN_DIR) --world microquickjs
+
+# Wasm object files
+$(BUILD_DIR)/mquickjs.o: mquickjs.c $(BUILD_DIR)/mquickjs_atom.h $(BUILD_DIR)/mqjs_stdlib.h | $(BUILD_DIR)
+	$(CC) $(CFLAGS) -I. -I$(BUILD_DIR) -c $< -o $@
+
+$(BUILD_DIR)/cutils.o: cutils.c | $(BUILD_DIR)
+	$(CC) $(CFLAGS) -I. -c $< -o $@
+
+$(BUILD_DIR)/dtoa.o: dtoa.c | $(BUILD_DIR)
+	$(CC) $(CFLAGS) -I. -c $< -o $@
+
+$(BUILD_DIR)/libm.o: libm.c | $(BUILD_DIR)
+	$(CC) $(CFLAGS) -I. -c $< -o $@
+
+$(BUILD_DIR)/microquickjs.o: $(GEN_DIR)/microquickjs.c | $(BUILD_DIR)
+	$(CC) $(CFLAGS) -I$(GEN_DIR) -c $< -o $@
+
+$(BUILD_DIR)/glue.o: glue.c $(GEN_DIR)/microquickjs.h $(BUILD_DIR)/mqjs_stdlib.h | $(BUILD_DIR)
+	$(CC) $(CFLAGS) -I. -I$(GEN_DIR) -I$(BUILD_DIR) -c $< -o $@
+
+$(BUILD_DIR)/wasi_preview1_stubs.o: wasi_preview1_stubs.c | $(BUILD_DIR)
+	$(CC) $(CFLAGS) -c $< -o $@
+
+# Core Wasm module
+$(BUILD_DIR)/core.wasm: $(OBJS) $(GEN_DIR)/microquickjs.c
+	$(CC) $(OBJS) $(GEN_DIR)/microquickjs_component_type.o $(LDFLAGS) -o $@
+
+# Final Component
+$(BUILD_DIR)/microquickjs.component.wasm: $(BUILD_DIR)/core.wasm microquickjs.wit $(ADAPTER)
+	wasm-tools component embed ./microquickjs.wit $< --world microquickjs --output $(BUILD_DIR)/embedded.wasm
+	wasm-tools component new $(BUILD_DIR)/embedded.wasm --adapt wasi_snapshot_preview1=$(ADAPTER) --output $@
+
+clean:
+	rm -rf $(BUILD_DIR) $(GEN_DIR) mquickjs_build_native
+
+.PHONY: all headers clean

README.WASI.md

@@ -0,0 +1,69 @@
+# MicroQuickJS WASI 0.2 Component
+
+This project ports MicroQuickJS to a WASI 0.2 WebAssembly Component.
+
+## Exported Interface
+
+The component exports the `engine` interface via the following WIT definition:
+
+```wit
+package local:microquickjs;
+
+interface engine {
+    resource js-value {
+        is-int:       func() -> bool;
+        is-bool:      func() -> bool;
+        is-null:      func() -> bool;
+        is-undefined: func() -> bool;
+        is-exception: func() -> bool;
+        is-number:    func() -> bool;
+        is-string:    func() -> bool;
+        is-error:     func() -> bool;
+        is-function:  func() -> bool;
+
+        to-string:  func() -> string;
+        to-int32:   func() -> s32;
+        to-float64: func() -> f64;
+
+        get-property: func(name: string) -> js-value;
+        set-property: func(name: string, val: borrow<js-value>);
+
+        call: func(args: list<borrow<js-value>>) -> js-value;
+    }
+
+    new-int32:  func(val: s32)    -> js-value;
+    new-float64: func(val: f64)   -> js-value;
+    new-bool:   func(val: bool)   -> js-value;
+    new-string: func(val: string) -> js-value;
+    new-object: func()            -> js-value;
+    new-array:  func()            -> js-value;
+
+    get-global-object: func() -> js-value;
+
+    eval: func(code: string) -> result<string, string>;
+}
+
+world microquickjs {
+    export engine;
+}
+```
+
+## Building
+
+Prerequisites:
+- **WASI SDK**: [https://github.com/WebAssembly/wasi-sdk](https://github.com/WebAssembly/wasi-sdk) (Set `WASI_SDK_PATH` to your installation directory).
+- **Tooling**: `wit-bindgen`, `wasm-tools`, `gcc` (for native helper).
+- **Adapter**: `wasi_snapshot_preview1.reactor.wasm` should be present in the root directory.
+
+Run the build:
+```bash
+make -f Makefile.wasi
+```
+
+The final component will be at `build/microquickjs.component.wasm`.
+
+## Architecture & Implementation
+
+- **Arena Memory**: Uses a fixed 4MiB static arena for JS heap, ensuring predictable memory footprint.
+- **Error Handling**: Uses the WebAssembly Exception Handling proposal for robust `setjmp/longjmp` support.
+- **Memory Safety**: Uses the Component Model Canonical ABI with `cabi_realloc` for all host-returned strings.

dtoa.c

@@ -35,7 +35,7 @@
 #include "cutils.h"
 #include "dtoa.h"
 
-/* 
+/*
    TODO:
    - test n_digits=101 instead of 100
    - simplify subnormal handling