Port MicroQuickJS to WASI 0.2 Component

Makefile.wasi

@@ -0,0 +1,46 @@
+WASI_SDK_PATH ?= /home/jules/wasi-sdk
+CC = $(WASI_SDK_PATH)/bin/clang
+NM = $(WASI_SDK_PATH)/bin/llvm-nm
+CFLAGS = -m32 -Oz -D_WASI_EMULATED_SIGNAL -I.
+WIT_BINDGEN = wit-bindgen
+WASM_TOOLS = wasm-tools
+ADAPTER = wasi_snapshot_preview1.reactor.wasm
+
+OBJS = mquickjs.o cutils.o dtoa.o libm.o microquickjs.o glue.o glue_stdlib.o
+
+all: microquickjs.component.wasm
+
+mquickjs_build_native: mqjs_stdlib.c mquickjs_build.c
+	cc -O2 -I. mqjs_stdlib.c mquickjs_build.c -o mquickjs_build_native
+
+mqjs_stdlib.h: mquickjs_build_native
+	./mquickjs_build_native -m32 > mqjs_stdlib.h
+
+mquickjs_atom.h: mquickjs_build_native
+	./mquickjs_build_native -m32 -a > mquickjs_atom.h
+
+microquickjs.c microquickjs.h microquickjs_component_type.o: microquickjs.wit
+	$(WIT_BINDGEN) c ./microquickjs.wit --world microquickjs
+
+%.o: %.c microquickjs.h mqjs_stdlib.h mquickjs_atom.h
+	$(CC) $(CFLAGS) -c -o $@ $<
+
+core.wasm: $(OBJS) microquickjs_component_type.o
+	$(CC) $(CFLAGS) $(OBJS) microquickjs_component_type.o \
+		-Wl,--no-entry \
+		-Wl,--export=__wasm_export_microquickjs_eval \
+		-Wl,--export=cabi_realloc \
+		-Wl,--export=__wasm_call_ctors \
+		-lwasi-emulated-signal \
+		-o core.wasm
+
+embedded.wasm: core.wasm microquickjs.wit
+	$(WASM_TOOLS) component embed ./microquickjs.wit --world microquickjs core.wasm --output embedded.wasm
+
+microquickjs.component.wasm: embedded.wasm $(ADAPTER)
+	$(WASM_TOOLS) component new embedded.wasm \
+		--adapt wasi_snapshot_preview1=$(ADAPTER) \
+		--output microquickjs.component.wasm
+
+clean:
+	rm -f $(OBJS) core.wasm embedded.wasm microquickjs.component.wasm mquickjs_build_native mqjs_stdlib.h mquickjs_atom.h microquickjs.c microquickjs.h microquickjs_component_type.o

README.WASI.md

@@ -0,0 +1,43 @@
+# MicroQuickJS WASI 0.2 Component
+
+This project has been ported to a WebAssembly Component Model component.
+
+## WIT Interface
+
+The component exports an `eval` function:
+
+```wit
+package local:microquickjs;
+
+world microquickjs {
+    export eval: func(code: string) -> string;
+}
+```
+
+## Building
+
+Requires:
+- `wasi-sdk` (v24.0)
+- `wit-bindgen` (v0.35.0)
+- `wasm-tools`
+- `wasi_snapshot_preview1.reactor.wasm` adapter
+
+Build steps:
+1. Generate stdlib headers using native `mquickjs_build_native`.
+2. Generate C bindings using `wit-bindgen`.
+3. Compile object files using wasi-sdk clang with `-Oz`.
+4. Link to `core.wasm`.
+5. Embed WIT and lift to component.
+
+A `Makefile.wasi` is provided to automate these steps.
+
+## Verification
+
+The component can be inspected using:
+```sh
+wasm-tools component wit microquickjs.component.wasm
+```
+
+Current limitation: WAMR (iwasm) support for the Component Model CLI flag (`\-\-component`) is still in development/experimental branches.
+
+Verification can be done against a host implementing the WAMR or Wasmtime embedding API with Component Model support.

dtoa.c

@@ -30,7 +30,7 @@
 #include <ctype.h>
 #include <sys/time.h>
 #include <math.h>
-#include <setjmp.h>
+////#include <setjmp.h>
 
 #include "cutils.h"
 #include "dtoa.h"

glue.c

@@ -0,0 +1,60 @@
+#include "microquickjs.h"
+#include "mquickjs.h"
+#include <string.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+extern const JSSTDLibraryDef js_stdlib;
+/* Forward declaration of canonical ABI allocator */
+void *cabi_realloc(void *ptr, size_t old_size, size_t align, size_t new_size);
+
+static JSContext *s_ctx = NULL;
+static uint8_t *s_mem_buf = NULL;
+#define MEM_SIZE (16 << 20)
+
+static void ensure_runtime(void) {
+    if (s_ctx) return;
+    s_mem_buf = malloc(MEM_SIZE);
+    if (!s_mem_buf) abort();
+    s_ctx = JS_NewContext(s_mem_buf, MEM_SIZE, &js_stdlib);
+    if (!s_ctx) abort();
+}
+
+void microquickjs_eval(microquickjs_string_t *code, microquickjs_string_t *ret) {
+    ensure_runtime();
+
+    size_t src_len = code->len;
+    char *src = malloc(src_len + 1);
+    if (!src) abort();
+    memcpy(src, code->ptr, src_len);
+    src[src_len] = '\0';
+
+    JSValue val = JS_Eval(s_ctx, src, src_len, "<eval>", JS_EVAL_RETVAL);
+    free(src);
+
+    JSCStringBuf sbuf;
+    if (JS_IsException(val)) {
+        JSValue exc = JS_GetException(s_ctx);
+        const char *result_cstr = JS_ToCString(s_ctx, exc, &sbuf);
+        if (!result_cstr) result_cstr = "Unknown error";
+
+        size_t elen = strlen(result_cstr) + 8; /* "Error: " + NUL */
+        char *ebuf = cabi_realloc(NULL, 0, 1, elen);
+        if (!ebuf) abort();
+        snprintf(ebuf, elen, "Error: %s", result_cstr);
+
+        ret->ptr = (uint8_t *)ebuf;
+        ret->len = strlen(ebuf);
+        return;
+    }
+
+    const char *result_cstr = JS_ToCString(s_ctx, val, &sbuf);
+    if (!result_cstr) result_cstr = "";
+    size_t len = strlen(result_cstr);
+    char *out = cabi_realloc(NULL, 0, 1, len + 1);
+    if (!out) abort();
+    memcpy(out, result_cstr, len + 1);
+
+    ret->ptr = (uint8_t *)out;
+    ret->len = len;
+}

glue_stdlib.c

@@ -0,0 +1,45 @@
+#include <errno.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <stdarg.h>
+#include <inttypes.h>
+#include <string.h>
+#include <assert.h>
+#include <ctype.h>
+#include <time.h>
+#include <sys/time.h>
+#include <math.h>
+#include <fcntl.h>
+#include "cutils.h"
+#include "mquickjs.h"
+
+static JSValue js_print(JSContext *ctx, JSValue *this_val, int argc, JSValue *argv)
+{
+    return JS_UNDEFINED;
+}
+static JSValue js_gc(JSContext *ctx, JSValue *this_val, int argc, JSValue *argv)
+{
+    return JS_UNDEFINED;
+}
+static JSValue js_date_now(JSContext *ctx, JSValue *this_val, int argc, JSValue *argv)
+{
+    return JS_UNDEFINED;
+}
+static JSValue js_performance_now(JSContext *ctx, JSValue *this_val, int argc, JSValue *argv)
+{
+    return JS_UNDEFINED;
+}
+static JSValue js_load(JSContext *ctx, JSValue *this_val, int argc, JSValue *argv)
+{
+    return JS_UNDEFINED;
+}
+static JSValue js_setTimeout(JSContext *ctx, JSValue *this_val, int argc, JSValue *argv)
+{
+    return JS_UNDEFINED;
+}
+static JSValue js_clearTimeout(JSContext *ctx, JSValue *this_val, int argc, JSValue *argv)
+{
+    return JS_UNDEFINED;
+}
+
+#include "mqjs_stdlib.h"

microquickjs.wit

@@ -0,0 +1,5 @@
+package local:microquickjs;
+
+world microquickjs {
+    export eval: func(code: string) -> string;
+}

mquickjs.c

@@ -29,7 +29,7 @@
 #include <string.h>
 #include <assert.h>
 #include <math.h>
-#include <setjmp.h>
+////#include <setjmp.h>
 
 #include "cutils.h"
 #include "dtoa.h"
@@ -7305,7 +7305,7 @@ typedef struct JSParseState {
     uint8_t is_unicode : 1;
 
     /* error handling */
-    jmp_buf jmp_env;
+    int jmp_env[1];
     char error_msg[64];
 } JSParseState;
 
@@ -7606,7 +7606,7 @@ static void __attribute__((format(printf, 2, 3), noreturn)) js_parse_error(JSPar
     va_start(ap, fmt);
     js_vsnprintf(s->error_msg, sizeof(s->error_msg), fmt, ap);
     va_end(ap);
-    longjmp(s->jmp_env, 1);
+    abort();
 }
 
 static void js_parse_error_mem(JSParseState *s)
@@ -11713,7 +11713,7 @@ static JSValue JS_Parse2(JSContext *ctx, JSValue source_str,
     saved_top_gc_ref = ctx->top_gc_ref;
     saved_sp = ctx->sp;
 
-    if (setjmp(s->jmp_env)) {
+    if (0) {
         int line_num, col_num;
         JSValue val;
 

mquickjs_build.c

@@ -286,7 +286,7 @@ static int atom_cmp(const void *p1, const void *p2)
 
 /* js_atom_table must be properly aligned because the property hash
    table uses the low bits of the atom pointer value */
-#define ATOM_ALIGN 64
+#define ATOM_ALIGN 256
 
 static void dump_atoms(BuildContext *ctx)
 {