1 files changed, 206 insertions, 0 deletions
diff --git a/library/std/src/sys/pal/hermit/os.rs b/library/std/src/sys/pal/hermit/os.rs
new file mode 100644
index 00000000000..a54536aecb8
--- /dev/null
+++ b/library/std/src/sys/pal/hermit/os.rs
@@ -0,0 +1,206 @@
+use super::abi;
+use crate::collections::HashMap;
+use crate::error::Error as StdError;
+use crate::ffi::{CStr, OsStr, OsString};
+use crate::fmt;
+use crate::io;
+use crate::marker::PhantomData;
+use crate::os::hermit::ffi::OsStringExt;
+use crate::path::{self, PathBuf};
+use crate::str;
+use crate::sync::Mutex;
+use crate::sys::memchr;
+use crate::sys::unsupported;
+use crate::vec;
+
+pub fn errno() -> i32 {
+    0
+}
+
+pub fn error_string(_errno: i32) -> String {
+    "operation successful".to_string()
+}
+
+pub fn getcwd() -> io::Result<PathBuf> {
+    unsupported()
+}
+
+pub fn chdir(_: &path::Path) -> io::Result<()> {
+    unsupported()
+}
+
+pub struct SplitPaths<'a>(!, PhantomData<&'a ()>);
+
+pub fn split_paths(_unparsed: &OsStr) -> SplitPaths<'_> {
+    panic!("unsupported")
+}
+
+impl<'a> Iterator for SplitPaths<'a> {
+    type Item = PathBuf;
+    fn next(&mut self) -> Option<PathBuf> {
+        self.0
+    }
+}
+
+#[derive(Debug)]
+pub struct JoinPathsError;
+
+pub fn join_paths<I, T>(_paths: I) -> Result<OsString, JoinPathsError>
+where
+    I: Iterator<Item = T>,
+    T: AsRef<OsStr>,
+{
+    Err(JoinPathsError)
+}
+
+impl fmt::Display for JoinPathsError {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        "not supported on hermit yet".fmt(f)
+    }
+}
+
+impl StdError for JoinPathsError {
+    #[allow(deprecated)]
+    fn description(&self) -> &str {
+        "not supported on hermit yet"
+    }
+}
+
+pub fn current_exe() -> io::Result<PathBuf> {
+    unsupported()
+}
+
+static mut ENV: Option<Mutex<HashMap<OsString, OsString>>> = None;
+
+pub fn init_environment(env: *const *const i8) {
+    unsafe {
+        ENV = Some(Mutex::new(HashMap::new()));
+
+        if env.is_null() {
+            return;
+        }
+
+        let mut guard = ENV.as_ref().unwrap().lock().unwrap();
+        let mut environ = env;
+        while !(*environ).is_null() {
+            if let Some((key, value)) = parse(CStr::from_ptr(*environ).to_bytes()) {
+                guard.insert(key, value);
+            }
+            environ = environ.add(1);
+        }
+    }
+
+    fn parse(input: &[u8]) -> Option<(OsString, OsString)> {
+        // Strategy (copied from glibc): Variable name and value are separated
+        // by an ASCII equals sign '='. Since a variable name must not be
+        // empty, allow variable names starting with an equals sign. Skip all
+        // malformed lines.
+        if input.is_empty() {
+            return None;
+        }
+        let pos = memchr::memchr(b'=', &input[1..]).map(|p| p + 1);
+        pos.map(|p| {
+            (
+                OsStringExt::from_vec(input[..p].to_vec()),
+                OsStringExt::from_vec(input[p + 1..].to_vec()),
+            )
+        })
+    }
+}
+
+pub struct Env {
+    iter: vec::IntoIter<(OsString, OsString)>,
+}
+
+// FIXME(https://github.com/rust-lang/rust/issues/114583): Remove this when <OsStr as Debug>::fmt matches <str as Debug>::fmt.
+pub struct EnvStrDebug<'a> {
+    slice: &'a [(OsString, OsString)],
+}
+
+impl fmt::Debug for EnvStrDebug<'_> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        let Self { slice } = self;
+        f.debug_list()
+            .entries(slice.iter().map(|(a, b)| (a.to_str().unwrap(), b.to_str().unwrap())))
+            .finish()
+    }
+}
+
+impl Env {
+    pub fn str_debug(&self) -> impl fmt::Debug + '_ {
+        let Self { iter } = self;
+        EnvStrDebug { slice: iter.as_slice() }
+    }
+}
+
+impl fmt::Debug for Env {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        let Self { iter } = self;
+        f.debug_list().entries(iter.as_slice()).finish()
+    }
+}
+
+impl !Send for Env {}
+impl !Sync for Env {}
+
+impl Iterator for Env {
+    type Item = (OsString, OsString);
+    fn next(&mut self) -> Option<(OsString, OsString)> {
+        self.iter.next()
+    }
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        self.iter.size_hint()
+    }
+}
+
+/// Returns a vector of (variable, value) byte-vector pairs for all the
+/// environment variables of the current process.
+pub fn env() -> Env {
+    unsafe {
+        let guard = ENV.as_ref().unwrap().lock().unwrap();
+        let mut result = Vec::new();
+
+        for (key, value) in guard.iter() {
+            result.push((key.clone(), value.clone()));
+        }
+
+        return Env { iter: result.into_iter() };
+    }
+}
+
+pub fn getenv(k: &OsStr) -> Option<OsString> {
+    unsafe { ENV.as_ref().unwrap().lock().unwrap().get_mut(k).cloned() }
+}
+
+pub fn setenv(k: &OsStr, v: &OsStr) -> io::Result<()> {
+    unsafe {
+        let (k, v) = (k.to_owned(), v.to_owned());
+        ENV.as_ref().unwrap().lock().unwrap().insert(k, v);
+    }
+    Ok(())
+}
+
+pub fn unsetenv(k: &OsStr) -> io::Result<()> {
+    unsafe {
+        ENV.as_ref().unwrap().lock().unwrap().remove(k);
+    }
+    Ok(())
+}
+
+pub fn temp_dir() -> PathBuf {
+    panic!("no filesystem on hermit")
+}
+
+pub fn home_dir() -> Option<PathBuf> {
+    None
+}
+
+pub fn exit(code: i32) -> ! {
+    unsafe {
+        abi::exit(code);
+    }
+}
+
+pub fn getpid() -> u32 {
+    unsafe { abi::getpid() }
+}