From e5f3e9642d82601eab22ad56b29a755bdede9bfb Mon Sep 17 00:00:00 2001
From: bjorn3 <17426603+bjorn3@users.noreply.github.com>
Date: Mon, 24 Jun 2024 12:47:33 +0200
Subject: [PATCH] Use origin's errno_location in the __errno_location
 implementation

This will help with integrating the musl dynamic linker until a rust
replacement is written.

cc sunfishcode/origin#110
---
 c-scape/Cargo.toml    |  2 +-
 c-scape/src/errno_.rs | 13 +++++++++----
 2 files changed, 10 insertions(+), 5 deletions(-)

diff --git a/c-scape/Cargo.toml b/c-scape/Cargo.toml
index c7d29ae..cf525e8 100644
--- a/c-scape/Cargo.toml
+++ b/c-scape/Cargo.toml
@@ -64,7 +64,7 @@ static_assertions = "1.1.0"
 
 [features]
 default = ["thread", "std", "coexist-with-libc", "threadsafe-setenv", "use-compiler-builtins"]
-thread = []
+thread = ["origin/unstable-errno"]
 std = ["rustix/std", "printf-compat/std"]
 
 # In "take-charge" mode, this enables code in c-scape to define the
diff --git a/c-scape/src/errno_.rs b/c-scape/src/errno_.rs
index f5fb970..d2d6ed7 100644
--- a/c-scape/src/errno_.rs
+++ b/c-scape/src/errno_.rs
@@ -1,7 +1,7 @@
 use alloc::borrow::ToOwned;
 use alloc::format;
 use core::cell::SyncUnsafeCell;
-use core::ptr::{addr_of_mut, copy_nonoverlapping, null_mut};
+use core::ptr::{copy_nonoverlapping, null_mut};
 use libc::{c_char, c_int};
 
 /// Return the address of the thread-local `errno` state.
@@ -13,9 +13,14 @@ use libc::{c_char, c_int};
 unsafe extern "C" fn __errno_location() -> *mut c_int {
     libc!(libc::__errno_location());
 
-    #[cfg_attr(feature = "thread", thread_local)]
-    static mut ERRNO: i32 = 0;
-    addr_of_mut!(ERRNO)
+    #[cfg(feature = "thread")]
+    return origin::thread::errno_location();
+
+    #[cfg(not(feature = "thread"))]
+    {
+        static mut ERRNO: i32 = 0;
+        return core::ptr::addr_of_mut!(ERRNO);
+    }
 }
 
 #[no_mangle]