Avoid sys-locale in host on macOS

Author: codegod100

Cargo.toml

@@ -13,14 +13,16 @@ crate-type = ["staticlib"]
 # Note: we use "=version" for reproducability, cargo may silently use a more recent version if you do not use `=`.
 [dependencies]
 libc = "=0.2.180" # keep version in sync with libc workspace dep below
-sys-locale.workspace = true
 crossterm = "0.27"
 roc_std_new.workspace = true
 roc_io_error.workspace = true
 roc_random.workspace = true
 roc_command.workspace = true
 memoffset = "=0.9.1"
 
+[target.'cfg(not(target_os = "macos"))'.dependencies]
+sys-locale.workspace = true
+
 [workspace]
 members = [
     "crates/roc_io_error",

crates/roc_host/Cargo.toml

@@ -16,7 +16,6 @@ path = "src/lib.rs"
 crossterm.workspace = true
 memmap2.workspace = true
 memchr.workspace = true
-sys-locale.workspace = true
 libc.workspace = true
 backtrace.workspace = true
 roc_std.workspace = true

src/lib.rs

@@ -669,8 +669,47 @@ unsafe fn write_try_bool_result(
     std::ptr::write(ret_ptr as *mut TryBoolPathErr, try_result);
 }
 
+#[cfg(target_os = "macos")]
+fn locale_from_env() -> Option<String> {
+    for key in ["LC_ALL", "LC_CTYPE", "LANG"] {
+        if let Ok(value) = std::env::var(key) {
+            let trimmed = value.trim();
+            if trimmed.is_empty() {
+                continue;
+            }
+            let locale = trimmed
+                .split('.')
+                .next()
+                .unwrap_or(trimmed)
+                .split('@')
+                .next()
+                .unwrap_or(trimmed)
+                .trim();
+            if !locale.is_empty() {
+                return Some(locale.to_string());
+            }
+        }
+    }
+
+    None
+}
+
+/// Hosted function: Locale.all!
+/// Takes {}, returns List(Str)
+#[cfg(target_os = "macos")]
+extern "C" fn hosted_locale_all(ops: *const RocOps, ret_ptr: *mut c_void, _args_ptr: *mut c_void) {
+    let roc_ops = unsafe { &*ops };
+    let locales = locale_from_env().unwrap_or_else(|| "en-US".to_string());
+    let mut list = RocList::with_capacity(1, roc_ops);
+    list.push(RocStr::from_str(&locales, roc_ops), roc_ops);
+    unsafe {
+        *(ret_ptr as *mut RocList<RocStr>) = list;
+    }
+}
+
 /// Hosted function: Locale.all!
 /// Takes {}, returns List(Str)
+#[cfg(not(target_os = "macos"))]
 extern "C" fn hosted_locale_all(ops: *const RocOps, ret_ptr: *mut c_void, _args_ptr: *mut c_void) {
     let roc_ops = unsafe { &*ops };
     let locales = sys_locale::get_locales().collect::<Vec<_>>();
@@ -686,6 +725,19 @@ extern "C" fn hosted_locale_all(ops: *const RocOps, ret_ptr: *mut c_void, _args_
 
 /// Hosted function: Locale.get!
 /// Takes {}, returns Str
+#[cfg(target_os = "macos")]
+extern "C" fn hosted_locale_get(ops: *const RocOps, ret_ptr: *mut c_void, _args_ptr: *mut c_void) {
+    let roc_ops = unsafe { &*ops };
+    let locale = locale_from_env().unwrap_or_else(|| "en-US".to_string());
+    let roc_str = RocStr::from_str(&locale, roc_ops);
+    unsafe {
+        *(ret_ptr as *mut RocStr) = roc_str;
+    }
+}
+
+/// Hosted function: Locale.get!
+/// Takes {}, returns Str
+#[cfg(not(target_os = "macos"))]
 extern "C" fn hosted_locale_get(ops: *const RocOps, ret_ptr: *mut c_void, _args_ptr: *mut c_void) {
     let roc_ops = unsafe { &*ops };
     let locale = sys_locale::get_locale().unwrap_or_else(|| "en-US".to_string());