wasm2c: uvwasi adapter layer for wasm2c output

Author: shravanrn

wasm2c/examples/hello-wasi/.gitignore

@@ -0,0 +1,5 @@
+*.o
+hello-wasi
+hello-wasi.wasm
+hello-wasi-wasm.*
+test.out

wasm2c/examples/hello-wasi/Makefile

@@ -0,0 +1,21 @@
+WABT_ROOT=../../..
+CC=clang
+CFLAGS=-I$(WABT_ROOT)/wasm2c -I$(WABT_ROOT)/third_party/uvwasi/include -O3
+LDFLAGS=-L$(WABT_ROOT)/build/_deps/libuv-build -L$(WABT_ROOT)/build/third_party/uvwasi
+LDLIBS=-luvwasi_a -luv_a -lm -lpthread
+
+all: hello-wasi
+
+clean:
+	rm -rf hello-wasi hello-wasi.wasm hello-wasi-wasm.c hello-wasi-wasm.h test.out *.o
+
+hello-wasi.wasm: hello-wasi.c
+	/opt/wasi-sdk/bin/clang -O3 $< -o $@
+
+hello-wasi-wasm.c: hello-wasi.wasm $(WABT_ROOT)/bin/wasm2c
+	$(WABT_ROOT)/bin/wasm2c $< -n hello_wasi -o $@
+
+hello-wasi: main.c hello-wasi-wasm.c $(WABT_ROOT)/wasm2c/wasm-rt-uvwasi-adapter.c $(WABT_ROOT)/wasm2c/wasm-rt-impl.c $(WABT_ROOT)/wasm2c/wasm-rt-mem-impl.c
+	$(CC) $(LDFLAGS) $(CFLAGS) $^ -o $@ $(LDLIBS)
+
+.PHONY: all clean

wasm2c/examples/hello-wasi/hello-wasi.c

@@ -0,0 +1,33 @@
+#include <assert.h>
+#include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+
+int main(int argc, char* argv[]) {
+  printf("printing args\n");
+  for (int i = 0; i < argc; i++) {
+    printf("[%d] %s \n", i, argv[i]);
+  }
+
+  printf("Writing to stdout\n");
+  char* hello_str = strdup("hello world!");
+  puts(hello_str);
+
+  printf("writing test.out\n");
+  FILE* fp = fopen("test.out", "w+");
+  assert(fp != NULL);
+  fprintf(fp, "hello filesystem\n");
+  fclose(fp);
+  printf("removing test.out\n");
+  assert(!unlink("test.out"));
+
+  printf("writing /tmp/test.out\n");
+  fp = fopen("/tmp/test.out", "w+");
+  assert(fp != NULL);
+  fprintf(fp, "hello filesystem\n");
+  fclose(fp);
+  printf("removing /tmp/test.out\n");
+  assert(!unlink("/tmp/test.out"));
+
+  return 0;
+}

wasm2c/examples/hello-wasi/main.c

@@ -0,0 +1,49 @@
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "hello-wasi-wasm.h"
+#include "wasm-rt-uvwasi-adapter.h"
+#include "uvwasi.h"
+
+int main(int argc, const char** argv) {
+  w2c_hello__wasi hello = {0};
+  struct w2c_wasi__snapshot__preview1 wasi = {0};
+  uvwasi_t uvwasi = {0};
+  uvwasi_options_t init_options = {0};
+  uvwasi_preopen_t preopens[2] = {0};
+
+  init_options.in = 0;
+  init_options.out = 1;
+  init_options.err = 2;
+  init_options.fd_table_size = 10;
+
+  extern const char** environ;
+  init_options.argc = argc;
+  init_options.argv = argv;
+  init_options.envp = (const char**)environ;
+
+  preopens[0].mapped_path = "/tmp";
+  preopens[0].real_path = "/tmp";
+  preopens[1].mapped_path = ".";
+  preopens[1].real_path = ".";
+  init_options.preopenc = 2;
+  init_options.preopens = preopens;
+  init_options.allocator = NULL;
+
+  wasm_rt_init();
+  uvwasi_errno_t ret = uvwasi_init(&uvwasi, &init_options);
+  if (ret != UVWASI_ESUCCESS) {
+    fprintf(stderr, "uvwasi_init failed with error %u\n", ret);
+    return 1;
+  }
+
+  wasm2c_uvwasi_link(&wasi, &hello.w2c_memory, &uvwasi);
+  wasm2c_hello__wasi_instantiate(&hello, &wasi);
+  w2c_hello__wasi_0x5Fstart(&hello);
+  wasm2c_hello__wasi_free(&hello);
+
+  uvwasi_destroy(&uvwasi);
+  wasm_rt_free();
+
+  return 0;
+}