Auto merge of #121800 - GuillaumeGomez:rollup-wob2qcz, r=GuillaumeGomez

Rollup of 10 pull requests

Successful merges:

 - #118217 (Document which methods on `f64` are precise)
 - #119748 (Increase visibility of `join_path` and `split_paths`)
 - #121412 (platform docs: clarify hexagon-unknown-none-elf example, add hexagon-unknown-linux-musl)
 - #121654 (Fix `async Fn` confirmation for `FnDef`/`FnPtr`/`Closure` types)
 - #121700 (CFI: Don't compress user-defined builtin types)
 - #121765 (add platform-specific function to get the error number for HermitOS)
 - #121781 (bootstrap/format: send larger batches to rustfmt)
 - #121788 (bootstrap: fix clap deprecated warnings)
 - #121792 (Improve renaming suggestion when item starts with underscore)
 - #121793 (Document which methods on `f32` are precise)

r? `@ghost`
`@rustbot` modify labels: rollup

1 files changed, 5 insertions, 5 deletions

diff --git a/library/std/src/sys/pal/hermit/os.rs b/library/std/src/sys/pal/hermit/os.rs
index a54536aecb8..645f0dc1e31 100644
--- a/library/std/src/sys/pal/hermit/os.rs
+++ b/library/std/src/sys/pal/hermit/os.rs
@@ -14,15 +14,15 @@ use crate::sys::unsupported;
 use crate::vec;
 
 pub fn errno() -> i32 {
-    0
+    unsafe { abi::get_errno() }
 }
 
-pub fn error_string(_errno: i32) -> String {
-    "operation successful".to_string()
+pub fn error_string(errno: i32) -> String {
+    abi::error_string(errno).to_string()
 }
 
 pub fn getcwd() -> io::Result<PathBuf> {
-    unsupported()
+    Ok(PathBuf::from("/"))
 }
 
 pub fn chdir(_: &path::Path) -> io::Result<()> {
@@ -188,7 +188,7 @@ pub fn unsetenv(k: &OsStr) -> io::Result<()> {
 }
 
 pub fn temp_dir() -> PathBuf {
-    panic!("no filesystem on hermit")
+    PathBuf::from("/tmp")
 }
 
 pub fn home_dir() -> Option<PathBuf> {