diff options
| -rw-r--r-- | library/std/src/sys/pal/unix/args.rs | 81 |
1 files changed, 44 insertions, 37 deletions
diff --git a/library/std/src/sys/pal/unix/args.rs b/library/std/src/sys/pal/unix/args.rs index 9f7dcc0416e..78e82d9c194 100644 --- a/library/std/src/sys/pal/unix/args.rs +++ b/library/std/src/sys/pal/unix/args.rs @@ -201,9 +201,9 @@ mod imp { // As _NSGetArgc and _NSGetArgv aren't mentioned in iOS docs // and use underscores in their names - they're most probably - // are considered private and therefore should be avoided - // Here is another way to get arguments using Objective C - // runtime + // are considered private and therefore should be avoided. + // Here is another way to get arguments using the Objective-C + // runtime. // // In general it looks like: // res = Vec::new() @@ -213,53 +213,60 @@ mod imp { // res #[cfg(any(target_os = "ios", target_os = "tvos", target_os = "watchos"))] pub fn args() -> Args { - use crate::ffi::OsString; + use crate::ffi::{c_char, c_void, OsString}; use crate::mem; use crate::str; - extern "C" { - fn sel_registerName(name: *const libc::c_uchar) -> Sel; - fn objc_getClass(class_name: *const libc::c_uchar) -> NsId; - } + type Sel = *const c_void; + type NsId = *const c_void; + type NSUInteger = usize; - #[cfg(target_arch = "aarch64")] extern "C" { - fn objc_msgSend(obj: NsId, sel: Sel) -> NsId; - #[allow(clashing_extern_declarations)] - #[link_name = "objc_msgSend"] - fn objc_msgSend_ul(obj: NsId, sel: Sel, i: libc::c_ulong) -> NsId; - } + fn sel_registerName(name: *const c_char) -> Sel; + fn objc_getClass(class_name: *const c_char) -> NsId; - #[cfg(not(target_arch = "aarch64"))] - extern "C" { - fn objc_msgSend(obj: NsId, sel: Sel, ...) -> NsId; - #[allow(clashing_extern_declarations)] - #[link_name = "objc_msgSend"] - fn objc_msgSend_ul(obj: NsId, sel: Sel, ...) -> NsId; + // This must be transmuted to an appropriate function pointer type before being called. + fn objc_msgSend(); } - type Sel = *const libc::c_void; - type NsId = *const libc::c_void; + const MSG_SEND_PTR: unsafe extern "C" fn() = objc_msgSend; + const MSG_SEND_NO_ARGUMENTS_RETURN_PTR: unsafe extern "C" fn(NsId, Sel) -> *const c_void = + unsafe { mem::transmute(MSG_SEND_PTR) }; + const MSG_SEND_NO_ARGUMENTS_RETURN_NSUINTEGER: unsafe extern "C" fn( + NsId, + Sel, + ) -> NSUInteger = unsafe { mem::transmute(MSG_SEND_PTR) }; + const MSG_SEND_NSINTEGER_ARGUMENT_RETURN_PTR: unsafe extern "C" fn( + NsId, + Sel, + NSUInteger, + ) + -> *const c_void = unsafe { mem::transmute(MSG_SEND_PTR) }; let mut res = Vec::new(); unsafe { - let process_info_sel = - sel_registerName(c"processInfo".as_ptr() as *const libc::c_uchar); - let arguments_sel = sel_registerName(c"arguments".as_ptr() as *const libc::c_uchar); - let utf8_sel = sel_registerName(c"UTF8String".as_ptr() as *const libc::c_uchar); - let count_sel = sel_registerName(c"count".as_ptr() as *const libc::c_uchar); - let object_at_sel = - sel_registerName(c"objectAtIndex:".as_ptr() as *const libc::c_uchar); - - let klass = objc_getClass(c"NSProcessInfo".as_ptr() as *const libc::c_uchar); - let info = objc_msgSend(klass, process_info_sel); - let args = objc_msgSend(info, arguments_sel); - - let cnt: usize = mem::transmute(objc_msgSend(args, count_sel)); + let process_info_sel = sel_registerName(c"processInfo".as_ptr()); + let arguments_sel = sel_registerName(c"arguments".as_ptr()); + let count_sel = sel_registerName(c"count".as_ptr()); + let object_at_index_sel = sel_registerName(c"objectAtIndex:".as_ptr()); + let utf8string_sel = sel_registerName(c"UTF8String".as_ptr()); + + let klass = objc_getClass(c"NSProcessInfo".as_ptr()); + // `+[NSProcessInfo processInfo]` returns an object with +0 retain count, so no need to manually `retain/release`. + let info = MSG_SEND_NO_ARGUMENTS_RETURN_PTR(klass, process_info_sel); + + // `-[NSProcessInfo arguments]` returns an object with +0 retain count, so no need to manually `retain/release`. + let args = MSG_SEND_NO_ARGUMENTS_RETURN_PTR(info, arguments_sel); + + let cnt = MSG_SEND_NO_ARGUMENTS_RETURN_NSUINTEGER(args, count_sel); for i in 0..cnt { - let tmp = objc_msgSend_ul(args, object_at_sel, i as libc::c_ulong); - let utf_c_str: *const libc::c_char = mem::transmute(objc_msgSend(tmp, utf8_sel)); + // `-[NSArray objectAtIndex:]` returns an object whose lifetime is tied to the array, so no need to manually `retain/release`. + let ns_string = + MSG_SEND_NSINTEGER_ARGUMENT_RETURN_PTR(args, object_at_index_sel, i); + // The lifetime of this pointer is tied to the NSString, as well as the current autorelease pool, which is why we heap-allocate the string below. + let utf_c_str: *const c_char = + MSG_SEND_NO_ARGUMENTS_RETURN_PTR(ns_string, utf8string_sel).cast(); let bytes = CStr::from_ptr(utf_c_str).to_bytes(); res.push(OsString::from(str::from_utf8(bytes).unwrap())) } |