userland/src/lib: add bloghelloworld

userland/src/lib/bloghelloworld.wast

@@ -0,0 +1,40 @@
+(module
+ ;; import functions from env
+ (func $close (import "env" "close") (param i32)         (result i32))
+ (func $open  (import "env" "open")  (param i32 i32)     (result i32))
+ (func $read  (import "env" "read")  (param i32 i32 i32) (result i32))
+ (func $write (import "env" "write") (param i32 i32 i32) (result i32))
+
+ ;; memory
+ (memory $mem 1)
+
+ ;; constants
+ (data (i32.const 200) "data")
+ (data (i32.const 230) "Hello, world!\n")
+
+ (func $main (result i32)
+       ;; $fd is the file descriptor of the file we're gonna open
+       (local $fd i32)
+
+       ;; $fd = $open("data", O_CREAT|O_RDWR);
+       (set_local $fd
+                  (call $open
+                        ;; pointer to the file name
+                        (i32.const 200)
+                        ;; flags, 42 for O_CREAT,O_RDWR
+                        (i32.const 42)))
+
+       ;; $write($fd, "Hello, World!\n", 14);
+       (call $write
+             (get_local $fd)
+             (i32.const 230)
+             (i32.const 14))
+       (drop)
+
+       ;; $close($fd);
+       (call $close
+             (get_local $fd))
+       (drop)
+
+       (i32.const 0))
+ (export "main" (func $main)))