Remove the dirs-next dependency

This crate hasn't been maintained in a while, and we only used it for
obtaining the home directory, which is easy enough to implement
ourselves.

On Windows we expect the USERPROFILE variable to be set, and we don't
have a fallback to SHGetFolderPathW(). As far as I can tell USERPROFILE
is usually set, so it should be good enough. In all cases if the home
directory is explicitly set to an empty string we ignore it, because
there's no scenario in which one would treat it any different from a
home directory not being set at all.

Changelog: changed

vm/Cargo.toml

@@ -13,7 +13,6 @@ doctest = false
 libffi-system = ["libffi/system"]
 
 [dependencies]
-dirs-next = "^1.0"
 libloading = "^0.7"
 libffi = "^3.0"
 crossbeam-utils = "^0.8"

vm/src/builtin_functions/env.rs

@@ -1,5 +1,4 @@
 //! Functions for setting/getting environment and operating system data.
-use crate::directories;
 use crate::mem::{Array, Pointer, String as InkoString};
 use crate::platform;
 use crate::process::ProcessPointer;
@@ -48,15 +47,22 @@ pub(crate) fn env_home_directory(
     _: ProcessPointer,
     _: &[Pointer],
 ) -> Result<Pointer, RuntimeError> {
-    let result = if let Some(path) = directories::home() {
-        InkoString::alloc(
-            state.permanent_space.string_class(),
-            canonalize(path),
-        )
+    // Rather than performing all sorts of magical incantations to get the home
+    // directory, we're just going to require that these environment variables
+    // are set.
+    let var = if cfg!(windows) {
+        state.environment.get("USERPROFILE")
     } else {
-        Pointer::undefined_singleton()
+        state.environment.get("HOME")
     };
 
+    // If the home is explicitly set to an empty string we still ignore it,
+    // because there's no scenario in which Some("") is useful.
+    let result = var
+        .cloned()
+        .filter(|p| unsafe { !InkoString::read(p).is_empty() })
+        .unwrap_or_else(Pointer::undefined_singleton);
+
     Ok(result)
 }
 
@@ -66,7 +72,7 @@ pub(crate) fn env_temp_directory(
     _: ProcessPointer,
     _: &[Pointer],
 ) -> Result<Pointer, RuntimeError> {
-    let path = canonalize(directories::temp());
+    let path = canonalize(env::temp_dir().to_string_lossy().into_owned());
 
     Ok(InkoString::alloc(state.permanent_space.string_class(), path))
 }
@@ -77,7 +83,9 @@ pub(crate) fn env_get_working_directory(
     _: ProcessPointer,
     _: &[Pointer],
 ) -> Result<Pointer, RuntimeError> {
-    let path = directories::working_directory().map(canonalize)?;
+    let path = env::current_dir()
+        .map(|path| path.to_string_lossy().into_owned())
+        .map(canonalize)?;
 
     Ok(InkoString::alloc(state.permanent_space.string_class(), path))
 }
@@ -90,7 +98,7 @@ pub(crate) fn env_set_working_directory(
 ) -> Result<Pointer, RuntimeError> {
     let dir = unsafe { InkoString::read(&arguments[0]) };
 
-    directories::set_working_directory(dir)?;
+    env::set_current_dir(dir)?;
     Ok(Pointer::nil_singleton())
 }
 

vm/src/lib.rs

@@ -9,7 +9,6 @@ pub mod arc_without_weak;
 pub mod builtin_functions;
 pub mod chunk;
 pub mod config;
-pub mod directories;
 pub mod execution_context;
 pub mod ffi;
 pub mod hasher;