From 8a2dba534ac2be43ffb577f314acfb38bc64c49e Mon Sep 17 00:00:00 2001
From: Mark McCaskey <mark@wasmer.io>
Date: Wed, 28 Aug 2019 13:19:06 -0700
Subject: [PATCH] Improve error handling, fix probable lifetime issue

---
 lib/wasi/src/lib.rs       |  8 ++++----
 lib/wasi/src/state/mod.rs | 24 +++++++++++++++++-------
 2 files changed, 21 insertions(+), 11 deletions(-)

diff --git a/lib/wasi/src/lib.rs b/lib/wasi/src/lib.rs
index f8294f83e..ce2059c6f 100644
--- a/lib/wasi/src/lib.rs
+++ b/lib/wasi/src/lib.rs
@@ -41,20 +41,20 @@ pub fn generate_import_object(
     mapped_dirs: Vec<(String, PathBuf)>,
 ) -> ImportObject {
     let state_gen = move || {
+        // TODO: look into removing all these unnecessary clones
         fn state_destructor(data: *mut c_void) {
-            dbg!("IN DESTRUCTOR");
-            dbg!(&data);
             unsafe {
                 drop(Box::from_raw(data as *mut WasiState));
             }
         }
+        let preopened_files = preopened_files.clone();
+        let mapped_dirs = mapped_dirs.clone();
 
         let state = Box::new(WasiState {
-            fs: WasiFs::new(&preopened_files, &mapped_dirs).unwrap(),
+            fs: WasiFs::new(&preopened_files, &mapped_dirs).expect("Could not create WASI FS"),
             args: args.clone(),
             envs: envs.clone(),
         });
-        dbg!("IN CONSTRUCTOR");
 
         (
             Box::into_raw(state) as *mut c_void,
diff --git a/lib/wasi/src/state/mod.rs b/lib/wasi/src/state/mod.rs
index a4154733d..64a5aee84 100644
--- a/lib/wasi/src/state/mod.rs
+++ b/lib/wasi/src/state/mod.rs
@@ -168,7 +168,7 @@ impl WasiFs {
             let inode = wasi_fs.create_virtual_root();
             let fd = wasi_fs
                 .create_fd(root_rights, root_rights, 0, Fd::READ, inode)
-                .expect("Could not create root fd");
+                .map_err(|e| format!("Could not create root fd: {}", e))?;
             wasi_fs.preopen_fds.push(fd);
             inode
         };
@@ -179,7 +179,13 @@ impl WasiFs {
             // TODO: think about this
             let default_rights = 0x1FFFFFFF; // all rights
             let cur_dir = PathBuf::from(dir);
-            let cur_dir_metadata = cur_dir.metadata().expect("Could not find directory");
+            let cur_dir_metadata = cur_dir.metadata().map_err(|e| {
+                format!(
+                    "Could not get metadata for file {:?}: {}",
+                    dir,
+                    e.to_string()
+                )
+            })?;
             let kind = if cur_dir_metadata.is_dir() {
                 Kind::Dir {
                     parent: Some(root_inode),
@@ -209,7 +215,7 @@ impl WasiFs {
                     Fd::READ | Fd::WRITE,
                     inode,
                 )
-                .expect("Could not open fd");
+                .map_err(|e| format!("Could not open fd for file {:?}: {}", dir, e))?;
             if let Kind::Root { entries } = &mut wasi_fs.inodes[root_inode].kind {
                 // todo handle collisions
                 assert!(entries.insert(dir.to_string(), inode).is_none())
@@ -221,9 +227,13 @@ impl WasiFs {
             debug!("Attempting to open {:?} at {}", real_dir, alias);
             // TODO: think about this
             let default_rights = 0x1FFFFFFF; // all rights
-            let cur_dir_metadata = real_dir
-                .metadata()
-                .expect("mapped dir not at previously verified location");
+            let cur_dir_metadata = real_dir.metadata().map_err(|e| {
+                format!(
+                    "Could not get metadata for file {:?}: {}",
+                    &real_dir,
+                    e.to_string()
+                )
+            })?;
             let kind = if cur_dir_metadata.is_dir() {
                 Kind::Dir {
                     parent: Some(root_inode),
@@ -253,7 +263,7 @@ impl WasiFs {
                     Fd::READ | Fd::WRITE,
                     inode,
                 )
-                .expect("Could not open fd");
+                .map_err(|e| format!("Could not open fd for file {:?}: {}", &real_dir, e))?;
             if let Kind::Root { entries } = &mut wasi_fs.inodes[root_inode].kind {
                 // todo handle collisions
                 assert!(entries.insert(alias.clone(), inode).is_none());