From 7cc967e709250af50473f9c8dcf3be4e9d518c03 Mon Sep 17 00:00:00 2001
From: Mark McCaskey <mark@wasmer.io>
Date: Mon, 20 May 2019 16:46:08 -0700
Subject: [PATCH] flip order of args in mapdir

---
 lib/wasi/src/lib.rs   |  2 +-
 lib/wasi/src/state.rs | 14 +++++++-------
 src/bin/wasmer.rs     | 13 ++++++++-----
 3 files changed, 16 insertions(+), 13 deletions(-)

diff --git a/lib/wasi/src/lib.rs b/lib/wasi/src/lib.rs
index 55459b74b..8621dc55e 100644
--- a/lib/wasi/src/lib.rs
+++ b/lib/wasi/src/lib.rs
@@ -30,7 +30,7 @@ pub fn generate_import_object(
     args: Vec<Vec<u8>>,
     envs: Vec<Vec<u8>>,
     preopened_files: Vec<String>,
-    mapped_dirs: Vec<(PathBuf, String)>,
+    mapped_dirs: Vec<(String, PathBuf)>,
 ) -> ImportObject {
     let state_gen = move || {
         fn state_destructor(data: *mut c_void) {
diff --git a/lib/wasi/src/state.rs b/lib/wasi/src/state.rs
index 3b03162ba..979d63d4d 100644
--- a/lib/wasi/src/state.rs
+++ b/lib/wasi/src/state.rs
@@ -177,7 +177,7 @@ pub struct WasiFs {
 impl WasiFs {
     pub fn new(
         preopened_dirs: &[String],
-        mapped_dirs: &[(PathBuf, String)],
+        mapped_dirs: &[(String, PathBuf)],
     ) -> Result<Self, String> {
         debug!("wasi::fs::inodes");
         let inodes = Arena::new();
@@ -218,28 +218,28 @@ impl WasiFs {
                 .expect("Could not open fd");
         }
         debug!("wasi::fs::mapped_dirs");
-        for (src_dir, dest_dir) in mapped_dirs {
-            debug!("Attempting to open {:?} at {}", src_dir, dest_dir);
+        for (alias, real_dir) in mapped_dirs {
+            debug!("Attempting to open {:?} at {}", dest_dir, alias);
             // TODO: think about this
             let default_rights = 0x1FFFFFFF; // all rights
-            let cur_dir_metadata = src_dir
+            let cur_dir_metadata = real_dir
                 .metadata()
                 .expect("mapped dir not at previously verified location");
             let kind = if cur_dir_metadata.is_dir() {
                 Kind::Dir {
                     parent: None,
-                    path: src_dir.clone(),
+                    path: real_dir.clone(),
                     entries: Default::default(),
                 }
             } else {
                 return Err(format!(
                     "WASI only supports pre-opened directories right now; found \"{:?}\"",
-                    &src_dir,
+                    &real_dir,
                 ));
             };
             // TODO: handle nested pats in `file`
             let inode_val =
-                InodeVal::from_file_metadata(&cur_dir_metadata, dest_dir.clone(), true, kind);
+                InodeVal::from_file_metadata(&cur_dir_metadata, alias.clone(), true, kind);
 
             let inode = wasi_fs.inodes.insert(inode_val);
             wasi_fs.inodes[inode].stat.st_ino = wasi_fs.inode_counter.get();
diff --git a/src/bin/wasmer.rs b/src/bin/wasmer.rs
index 1c232e1e6..bc4da1c85 100644
--- a/src/bin/wasmer.rs
+++ b/src/bin/wasmer.rs
@@ -234,16 +234,19 @@ fn execute_wasm(options: &Run) -> Result<(), String> {
     let mapped_dirs = {
         let mut md = vec![];
         for entry in options.mapped_dirs.iter() {
-            if let &[source, dest] = &entry.split(':').collect::<Vec<&str>>()[..] {
-                let pb = PathBuf::from(&source);
+            if let &[alias, real_dir] = &entry.split(':').collect::<Vec<&str>>()[..] {
+                let pb = PathBuf::from(&real_dir);
                 if let Ok(pb_metadata) = pb.metadata() {
                     if !pb_metadata.is_dir() {
-                        return Err(format!("\"{}\" exists, but it is not a directory", &source));
+                        return Err(format!(
+                            "\"{}\" exists, but it is not a directory",
+                            &real_dir
+                        ));
                     }
                 } else {
-                    return Err(format!("Directory \"{}\" does not exist", &source));
+                    return Err(format!("Directory \"{}\" does not exist", &real_dir));
                 }
-                md.push((pb, dest.to_string()));
+                md.push((alias.to_string(), pb));
                 continue;
             }
             return Err(format!(