Add errno in the libcc2rs compat layer

Author: lucic71

libcc2rs/src/compat.rs

@@ -11,6 +11,14 @@ unsafe extern "C" {
     #[cfg(target_os = "macos")]
     #[link_name = "malloc_size"]
     fn platform_malloc_size(ptr: *const c_void) -> usize;
+
+    #[cfg(target_os = "linux")]
+    #[link_name = "__errno_location"]
+    fn platform_errno_location() -> *mut i32;
+
+    #[cfg(target_os = "macos")]
+    #[link_name = "__error"]
+    fn platform_errno_location() -> *mut i32;
 }
 
 /// # Safety
@@ -28,3 +36,7 @@ pub unsafe fn malloc_usable_size(ptr: *mut c_void) -> usize {
         unsafe { platform_malloc_size(ptr as *const c_void) }
     }
 }
+
+pub unsafe fn cpp2rust_errno() -> *mut i32 {
+    platform_errno_location()
+}

rules/errno/ir_unsafe.json

@@ -2,7 +2,7 @@
   "f1": {
     "body": [
       {
-        "text": "libc::__errno_location()"
+        "text": "libcc2rs::cpp2rust_errno()"
       }
     ],
     "return_type": {

rules/errno/src.c

@@ -3,4 +3,4 @@
 
 #include <errno.h>
 
-int *f1(void) { return __errno_location(); }
+int *f1(void) { return cpp2rust_errno(); }

rules/errno/tgt_unsafe.rs

@@ -2,5 +2,5 @@
 // Distributed under the MIT license that can be found in the LICENSE file.
 
 unsafe fn f1() -> *mut i32 {
-    libc::__errno_location()
+    libcc2rs::cpp2rust_errno()
 }

tests/unit/out/unsafe/errno.rs

@@ -7,25 +7,25 @@ use std::io::{Read, Seek, Write};
 use std::os::fd::{AsFd, FromRawFd, IntoRawFd};
 use std::rc::Rc;
 pub unsafe fn test_errno_0() {
-    (*libc::__errno_location()) = 0;
-    assert!(((((*libc::__errno_location()) == (0)) as i32) != 0));
-    (*libc::__errno_location()) = 42;
-    assert!(((((*libc::__errno_location()) == (42)) as i32) != 0));
-    let mut saved: i32 = (*libc::__errno_location());
+    (*libcc2rs::cpp2rust_errno()) = 0;
+    assert!(((((*libcc2rs::cpp2rust_errno()) == (0)) as i32) != 0));
+    (*libcc2rs::cpp2rust_errno()) = 42;
+    assert!(((((*libcc2rs::cpp2rust_errno()) == (42)) as i32) != 0));
+    let mut saved: i32 = (*libcc2rs::cpp2rust_errno());
     assert!(((((saved) == (42)) as i32) != 0));
-    (*libc::__errno_location()) = 0;
+    (*libcc2rs::cpp2rust_errno()) = 0;
 }
 pub unsafe fn test_errno_preserved_across_strdup_1() {
-    (*libc::__errno_location()) = 99;
+    (*libcc2rs::cpp2rust_errno()) = 99;
     let mut d: *mut u8 =
         libc::strdup((b"hello\0".as_ptr().cast_mut()).cast_const() as *const i8) as *mut u8;
     assert!((((!((d).is_null())) as i32) != 0));
-    assert!(((((*libc::__errno_location()) == (99)) as i32) != 0));
+    assert!(((((*libcc2rs::cpp2rust_errno()) == (99)) as i32) != 0));
     libc::free((d as *mut u8 as *mut ::libc::c_void));
-    (*libc::__errno_location()) = 0;
+    (*libcc2rs::cpp2rust_errno()) = 0;
 }
 pub unsafe fn test_errno_from_fseek_2() {
-    (*libc::__errno_location()) = 0;
+    (*libcc2rs::cpp2rust_errno()) = 0;
     let mut r: i32 = if (match 0 {
         0 => (*libcc2rs::cin_unsafe()).seek(std::io::SeekFrom::Start(0_i64 as u64)),
         1 => (*libcc2rs::cin_unsafe()).seek(std::io::SeekFrom::Current(0_i64)),
@@ -39,8 +39,8 @@ pub unsafe fn test_errno_from_fseek_2() {
         -1
     };
     assert!(((((r) == (-1_i32)) as i32) != 0));
-    assert!(((((*libc::__errno_location()) == (29)) as i32) != 0));
-    (*libc::__errno_location()) = 0;
+    assert!(((((*libcc2rs::cpp2rust_errno()) == (29)) as i32) != 0));
+    (*libcc2rs::cpp2rust_errno()) = 0;
 }
 pub fn main() {
     unsafe {