Insulate API from intricacies of memory mgmt of calling runtimes

src/ctx.rs

@@ -1,6 +1,5 @@
 use crate::fdentry::FdEntry;
 use crate::host;
-use crate::wasm32;
 
 use failure::{bail, format_err, Error};
 use nix::unistd::dup;
@@ -11,17 +10,6 @@ use std::io::{stderr, stdin, stdout};
 use std::os::unix::prelude::{AsRawFd, FromRawFd, IntoRawFd, RawFd};
 use std::path::{Path, PathBuf};
 
-pub trait VmContext {
-    fn as_wasi_ctx(&self) -> *const WasiCtx;
-    fn as_wasi_ctx_mut(&mut self) -> *mut WasiCtx;
-
-    unsafe fn dec_ptr(
-        &mut self,
-        ptr: wasm32::uintptr_t,
-        len: usize,
-    ) -> Result<*mut u8, host::__wasi_errno_t>;
-}
-
 pub struct WasiCtxBuilder {
     fds: HashMap<host::__wasi_fd_t, FdEntry>,
     preopens: HashMap<PathBuf, File>,
@@ -198,16 +186,6 @@ pub struct WasiCtx {
     pub env: Vec<CString>,
 }
 
-impl Default for WasiCtx {
-    fn default() -> Self {
-        Self {
-            fds: HashMap::new(),
-            args: Vec::new(),
-            env: Vec::new(),
-        }
-    }
-}
-
 impl WasiCtx {
     /// Make a new `WasiCtx` with some default settings.
     ///