From 3668bbdf3ac05f2cc458baf30640b9d2f66c0d65 Mon Sep 17 00:00:00 2001
From: Mark Poliakov <mark@alnyan.me>
Date: Tue, 14 Nov 2023 14:39:15 +0200
Subject: [PATCH] alnyan/yggdrasil: [unsafe] make env writable

---
 library/std/src/sys/yggdrasil/mod.rs | 22 +++++++++++--
 library/std/src/sys/yggdrasil/os.rs  | 47 +++++++++++++---------------
 2 files changed, 41 insertions(+), 28 deletions(-)

diff --git a/library/std/src/sys/yggdrasil/mod.rs b/library/std/src/sys/yggdrasil/mod.rs
index 211f206bb75..d181bd052d7 100644
--- a/library/std/src/sys/yggdrasil/mod.rs
+++ b/library/std/src/sys/yggdrasil/mod.rs
@@ -1,7 +1,11 @@
 #![allow(unused)]
 #![allow(nonstandard_style)]
 
+use crate::collections::HashMap;
+use crate::ffi::OsString;
 use crate::io::{Error as IoError, ErrorKind, RawOsError};
+use crate::mem::MaybeUninit;
+use crate::str::FromStr;
 
 #[path = "../unix/cmath.rs"]
 pub mod cmath;
@@ -43,7 +47,8 @@ use crate::path::Path;
 // 0x000: args pointer
 // 0x008: envs pointer
 static mut ARGS: usize = 0;
-static mut ENVS: usize = 0;
+// TODO handle this in better way
+static mut ENVS: MaybeUninit<HashMap<OsString, OsString>> = MaybeUninit::uninit();
 
 #[doc(hidden)]
 pub trait IsNegative {
@@ -168,7 +173,20 @@ unsafe fn init_kernel_arg(program_arg: usize) {
     let hdr = program_arg as *const Header;
 
     ARGS = (*hdr).args_ptr;
-    ENVS = (*hdr).envs_ptr;
+    let env_list = util::KStringList::new((*hdr).envs_ptr);
+
+    let mut envs = ENVS.write(HashMap::new());
+
+    for i in 0..env_list.len() {
+        let line = env_list.get(i);
+        let Some((key, value)) = line.split_once('=') else {
+            continue;
+        };
+        let key = OsString::from_str(key).unwrap();
+        let value = OsString::from_str(value).unwrap();
+
+        envs.insert(key, value);
+    }
 }
 
 #[cfg(not(test))]
diff --git a/library/std/src/sys/yggdrasil/os.rs b/library/std/src/sys/yggdrasil/os.rs
index b596c6b8472..6daa2f72d70 100644
--- a/library/std/src/sys/yggdrasil/os.rs
+++ b/library/std/src/sys/yggdrasil/os.rs
@@ -1,3 +1,4 @@
+use crate::collections::hash_map;
 use crate::error::Error as StdError;
 use crate::ffi::{OsStr, OsString};
 use crate::fmt;
@@ -12,8 +13,7 @@ use yggdrasil_rt::Error as OsError;
 pub struct SplitPaths<'a>(!, PhantomData<&'a ()>);
 
 pub struct Env {
-    list: KStringList,
-    index: usize,
+    it: hash_map::Iter<'static, OsString, OsString>,
 }
 
 impl !Send for Env {}
@@ -23,26 +23,15 @@ impl Iterator for Env {
     type Item = (OsString, OsString);
 
     fn next(&mut self) -> Option<(OsString, OsString)> {
-        loop {
-            if self.index >= self.list.len() {
-                return None;
-            }
-            let item_str = self.list.get(self.index);
-            self.index += 1;
-
-            let Some((key, value)) = item_str.split_once('=') else {
-                continue;
-            };
-
-            let key = OsString::from_str(key).unwrap();
-            let value = OsString::from_str(value).unwrap();
-            break Some((key, value));
+        match self.it.next() {
+            Some((k, v)) => Some((k.clone(), v.clone())),
+            None => None,
         }
     }
 
-    // fn size_hint(&self) -> (usize, Option<usize>) {
-    //     todo!()
-    // }
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        self.it.size_hint()
+    }
 }
 
 pub fn split_paths(_path: &OsStr) -> SplitPaths<'_> {
@@ -122,17 +111,23 @@ pub fn current_exe() -> io::Result<PathBuf> {
 }
 
 pub fn env() -> Env {
-    Env { list: unsafe { KStringList::new(super::ENVS) }, index: 0 }
+    Env { it: unsafe { super::ENVS.assume_init_ref().iter() } }
 }
 
-pub fn getenv(_name: &OsStr) -> Option<OsString> {
-    todo!()
+pub fn getenv(name: &OsStr) -> Option<OsString> {
+    unsafe { super::ENVS.assume_init_ref().get(name).cloned() }
 }
 
-pub fn setenv(_name: &OsStr, _value: &OsStr) -> io::Result<()> {
-    todo!()
+pub fn setenv(name: &OsStr, value: &OsStr) -> io::Result<()> {
+    unsafe {
+        super::ENVS.assume_init_mut().insert(name.to_owned(), value.to_owned());
+    }
+    Ok(())
 }
 
-pub fn unsetenv(_name: &OsStr) -> io::Result<()> {
-    todo!()
+pub fn unsetenv(name: &OsStr) -> io::Result<()> {
+    unsafe {
+        super::ENVS.assume_init_mut().remove(name);
+    }
+    Ok(())
 }