Stub out WASI support to make things compile

src/lib.rs

@@ -31,6 +31,9 @@ cfg_if! {
     } else if #[cfg(target_os = "redox")] {
         mod redox;
         use redox as sys;
+    } else if #[cfg(target_os = "wasi")] {
+        mod wasi;
+        use wasi as sys;
     } else {
         mod lin;
         use lin as sys;

src/wasi.rs

@@ -0,0 +1,22 @@
+// TODO: flesh this out once actual WASI APIs for this are designed.
+//
+// For now here are just enough definitions to make things *compile*.
+
+use std::path::PathBuf;
+
+pub fn home_dir()       -> Option<PathBuf> { None }
+pub fn cache_dir()      -> Option<PathBuf> { None }
+pub fn config_dir()     -> Option<PathBuf> { None }
+pub fn data_dir()       -> Option<PathBuf> { None }
+pub fn data_local_dir() -> Option<PathBuf> { None }
+pub fn runtime_dir()    -> Option<PathBuf> { None }
+pub fn executable_dir() -> Option<PathBuf> { None }
+pub fn audio_dir()      -> Option<PathBuf> { None }
+pub fn desktop_dir()    -> Option<PathBuf> { None }
+pub fn document_dir()   -> Option<PathBuf> { None }
+pub fn download_dir()   -> Option<PathBuf> { None }
+pub fn font_dir()       -> Option<PathBuf> { None }
+pub fn picture_dir()    -> Option<PathBuf> { None }
+pub fn public_dir()     -> Option<PathBuf> { None }
+pub fn template_dir()   -> Option<PathBuf> { None }
+pub fn video_dir()      -> Option<PathBuf> { None }