Remove dep on hostprint and make mmaps linux only

Signed-off-by: James Sturtevant <jsturtevant@gmail.com>

Author: jsturtevant

src/hyperlight_wasm/src/sandbox/wasm_sandbox.rs

@@ -17,6 +17,7 @@ limitations under the License.
 use std::path::Path;
 use std::sync::Arc;
 
+#[cfg(target_os = "linux")]
 use hyperlight_host::mem::memory_region::{MemoryRegion, MemoryRegionFlags, MemoryRegionType};
 use hyperlight_host::sandbox::snapshot::Snapshot;
 use hyperlight_host::{MultiUseSandbox, Result, new_error};
@@ -107,6 +108,7 @@ impl WasmSandbox {
     /// It is the caller's responsibility to ensure that the host side
     /// of the region remains intact and is not written to until the
     /// produced LoadedWasmSandbox is discarded or devolved.
+    #[cfg(target_os = "linux")]
     pub unsafe fn load_module_by_mapping(
         mut self,
         base: *mut libc::c_void,

src/hyperlight_wasm_runtime/src/module.rs

@@ -157,23 +157,6 @@ fn init_wasm_runtime(function_call: FunctionCall) -> Result<Vec<u8>> {
         )?;
     }
 
-
-    let host_print_def = hostfuncs::HostFunctionDefinition {
-        function_name: "HostPrint".to_string(),
-        parameter_types: Some(alloc::vec![ParameterType::String]),
-        return_type: ReturnType::Int,
-    };
-    let captured = host_print_def.clone();
-    linker.func_new(
-        "env",
-        "HostPrint",
-        hostfuncs::hostfunc_type(&host_print_def, &engine)?,
-        move |c, ps, rs| {
-            hostfuncs::call(&captured, c, ps, rs)
-                .map_err(|e| wasmtime::Error::msg(format!("{:?}", e)))
-        },
-    )?;
-
     *CUR_ENGINE.lock() = Some(engine);
     *CUR_LINKER.lock() = Some(linker);
     Ok(get_flatbuffer_result::<i32>(0))

src/rust_wasm_samples/src/lib.rs

@@ -14,14 +14,8 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
-use std::ffi::CString;
 mod hostfuncs {
 
-    use std::os::raw::c_char;
-    extern "C" {
-        pub fn HostPrint(s: *const c_char) -> i32;
-    }
-
     mod host {
         extern "C" {
             #[link_name = "TestHostFunc"]
@@ -33,15 +27,31 @@ mod hostfuncs {
     }
 }
 
+#[link(wasm_import_module = "wasi_snapshot_preview1")]
+extern "C" {
+    fn fd_write(fd: i32, iovs: i32, iovs_len: i32, retptr: i32) -> i32;
+}
+
+fn wasi_print(s: &str) -> i32 {
+    let buf = s.as_ptr();
+    let len = s.len();
+    let iov: [u32; 2] = [buf as u32, len as u32];
+    let mut written: u32 = 0;
+    unsafe {
+        fd_write(
+            1, // stdout
+            iov.as_ptr() as i32,
+            1, // one iovec
+            &mut written as *mut u32 as i32,
+        );
+    }
+    written as i32
+}
+
 macro_rules! hlprint {
     ($($arg:tt)*) => {{
         let f = format!($($arg)*);
-        let s = CString::new(f).unwrap();
-        let r;
-        unsafe {
-            r = hostfuncs::HostPrint(s.as_ptr());
-        }
-        r
+        wasi_print(&f)
     }}
 }
 

src/wasmsamples/RunWasm.c

@@ -22,8 +22,6 @@ limitations under the License.
 #include <ctype.h>
 #include <math.h>
 
-int HostPrint(char* msg); // Implementation of this will be available in the native host
-
 int64_t GetTimeSinceBootMicrosecond();
 
 __attribute__((export_name("CalcFib")))
@@ -53,7 +51,7 @@ void* ReceiveByteArray(void* data, int length) {
 __attribute__((export_name("WasmPrintUsingHostPrint")))
 int WasmPrintUsingHostPrint(char* msg)
 {
-    HostPrint(msg); // Host borrows msg
+    printf("%s", msg);
     int len = strlen(msg);
     free(msg); // Free the param since we own
     return len;
@@ -69,7 +67,7 @@ void PrintHelloWorld()
 __attribute__((export_name("Print")))
 void Print(char* msg)
 {
-    HostPrint(msg);
+    printf("%s", msg);
     free(msg); // Free the msg since we own it
 }
 
@@ -99,7 +97,7 @@ char* ToUpper(char* msg)
 __attribute__((export_name("PrintUpper"), optnone))
 void PrintUpper(char* msg)
 {
-    HostPrint(ToUpper(msg));
+    printf("%s", ToUpper(msg));
     free(msg);
 }