hello world in C

cmd/land/process.go

@@ -229,7 +229,7 @@ func (p *Process) open(fnamesP int32, flags int32) int32 {
 	case "stdout":
 		fi = stdFD{
 			ReadWriteCloser: loggerFile{
-				Logger: log.New(os.Stdout, p.name, log.LstdFlags),
+				Logger: log.New(os.Stdout, p.name+" ", log.LstdFlags),
 			},
 		}
 

cmd/land/process_test.go

@@ -20,6 +20,7 @@ func testWasmFile(t *testing.T, fname string) *Process {
 	if err != nil {
 		t.Fatal(err)
 	}
+	p.name = fname
 
 	ret, err := p.Main()
 	if err != nil {
@@ -111,3 +112,7 @@ func TestStruct(t *testing.T) {
 		t.Fatalf("wanted foo.baz to be 255, got: %d", foo.Baz)
 	}
 }
+
+func TestCHelloWorld(t *testing.T) {
+	testWasmFile(t, "./testdata/helloworld.wasm")
+}

cmd/land/testdata/Tupfile

@@ -2,7 +2,8 @@ include_rules
 
 CFLAGS += --target=wasm32-unknown-unknown-wasm
 CFLAGS += --sysroot=~/code/wasmception/sysroot/
-CFLAGS += -O0 -nostartfiles -Wl,--no-entry -nostdlib
+CFLAGS += -O0 -nostartfiles -nostdlib -fvisibility=hidden
+CFLAGS += -Wl,--no-entry,--allow-undefined-file=land.syms
 
 : foreach *.wast |> wat2wasm -o %o %f |> %B.wasm
 : foreach *.c |>  ~/code/wasmception/dist/bin/clang $(CFLAGS) %f -o %o |> %B.wasm

cmd/land/testdata/helloworld.c

@@ -4,18 +4,11 @@ extern int close(int);
 
 __attribute__ ((visibility ("default")))
 int main() {
-  const char *name = "hello";
+  const char *name = "stdout";
   char *msg = "Hello, world!";
   int fd = open(name, 0x42);
-  int num = write(fd, msg, 13);
-  if (num == 0) {
-    return 1;
-  }
-
-  num = close(fd);
-  if (num == 0) {
-    return 1;
-  }
+  write(fd, msg, 13);
+  close(fd);
 
   return 0;
 }

cmd/land/testdata/land.syms

@@ -0,0 +1,6 @@
+open
+read
+write
+close
+unlink
+isatty