cmd/land: support stdout, fizzbuzz

cmd/land/process.go

@@ -227,6 +227,11 @@ func (p *Process) open(fnamesP int32, flags int32) int32 {
 	var err error
 	switch str {
 	case "stdout":
+		fi = stdFD{
+			ReadWriteCloser: os.Stdout,
+		}
+
+	case "log":
 		fi = stdFD{
 			ReadWriteCloser: loggerFile{
 				Logger: log.New(os.Stdout, p.name+" ", log.LstdFlags),

cmd/land/process_test.go

@@ -116,3 +116,7 @@ func TestStruct(t *testing.T) {
 func TestCHelloWorld(t *testing.T) {
 	testWasmFile(t, "./testdata/helloworld.wasm")
 }
+
+func TestFizzbuzz(t *testing.T) {
+	testWasmFile(t, "./testdata/fizzbuzz.wasm")
+}

cmd/land/testdata/fizzbuzz.c

@@ -0,0 +1,71 @@
+extern int open(const char *, int);
+extern int write(int, char *, int);
+
+char intToLetter(int i) {
+  switch (i) {
+  case 0:
+    return '0';
+  case 1:
+    return '1';
+  case 2:
+    return '2';
+  case 3:
+    return '3';
+  case 4:
+    return '4';
+  case 5:
+    return '5';
+  case 6:
+    return '6';
+  case 7:
+    return '7';
+  case 8:
+    return '8';
+  case 9:
+    return '9';
+  }
+
+  return '?';
+}
+
+char* makeIntString(int i) {
+  char a[3];
+
+  int hundreds = i / 100;
+  int tens = (i/10) % 10;
+  int ones = i % 10;
+
+  a[0] = intToLetter(hundreds);
+  a[1] = intToLetter(tens);
+  a[2] = intToLetter(ones);
+
+  return a;
+}
+
+__attribute__ ((visibility ("default")))
+int main() {
+  int fd;
+  int x;
+
+  fd = open("stdout", 0x42);
+
+  for (x = 0; x < 100; x++) {
+    int wrote = 0;
+    if (x % 3 == 0) {
+      wrote = 1;
+      write(fd, "Fizz", 4);
+    }
+    if (x % 5 == 0) {
+      wrote = 1;
+      write(fd, "Buzz", 4);
+    }
+
+    if (wrote == 0) {
+      write(fd, makeIntString(x), 3);
+    }
+
+    write(fd, "\n", 1);
+  }
+
+  return 0;
+}