1 files changed, 279 insertions, 0 deletions
diff --git a/third_party/rust/objc/src/encode.rs b/third_party/rust/objc/src/encode.rs
new file mode 100644
index 0000000000..921479da98
--- /dev/null
+++ b/third_party/rust/objc/src/encode.rs
@@ -0,0 +1,279 @@
+use std::ffi::CStr;
+use std::fmt;
+use std::os::raw::{c_char, c_void};
+use std::str;
+use malloc_buf::MallocBuffer;
+
+use runtime::{Class, Object, Sel};
+
+const QUALIFIERS: &'static [char] = &[
+    'r', // const
+    'n', // in
+    'N', // inout
+    'o', // out
+    'O', // bycopy
+    'R', // byref
+    'V', // oneway
+];
+
+#[cfg(target_pointer_width = "64")]
+const CODE_INLINE_CAP: usize = 30;
+
+#[cfg(target_pointer_width = "32")]
+const CODE_INLINE_CAP: usize = 14;
+
+enum Code {
+    Slice(&'static str),
+    Owned(String),
+    Inline(u8, [u8; CODE_INLINE_CAP]),
+    Malloc(MallocBuffer<u8>)
+}
+
+/// An Objective-C type encoding.
+///
+/// For more information, see Apple's documentation:
+/// <https://developer.apple.com/library/mac/documentation/Cocoa/Conceptual/ObjCRuntimeGuide/Articles/ocrtTypeEncodings.html>
+pub struct Encoding {
+    code: Code,
+}
+
+impl Encoding {
+    /// Constructs an `Encoding` from its string representation.
+    /// Unsafe because the caller must ensure the string is a valid encoding.
+    pub unsafe fn from_str(code: &str) -> Encoding {
+        from_str(code)
+    }
+
+    /// Returns self as a `str`.
+    pub fn as_str(&self) -> &str {
+        match self.code {
+            Code::Slice(code) => code,
+            Code::Owned(ref code) => code,
+            Code::Inline(len, ref bytes) => unsafe {
+                str::from_utf8_unchecked(&bytes[..len as usize])
+            },
+            Code::Malloc(ref buf) => unsafe {
+                str::from_utf8_unchecked(&buf[..buf.len() - 1])
+            },
+        }
+    }
+}
+
+impl Clone for Encoding {
+    fn clone(&self) -> Encoding {
+        if let Code::Slice(code) = self.code {
+            from_static_str(code)
+        } else {
+            from_str(self.as_str())
+        }
+    }
+}
+
+impl PartialEq for Encoding {
+    fn eq(&self, other: &Encoding) -> bool {
+        // strip qualifiers when comparing
+        let s = self.as_str().trim_left_matches(QUALIFIERS);
+        let o = other.as_str().trim_left_matches(QUALIFIERS);
+        s == o
+    }
+}
+
+impl fmt::Debug for Encoding {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "{}", self.as_str())
+    }
+}
+
+pub fn from_static_str(code: &'static str) -> Encoding {
+    Encoding { code: Code::Slice(code) }
+}
+
+pub fn from_str(code: &str) -> Encoding {
+    if code.len() > CODE_INLINE_CAP {
+        Encoding { code: Code::Owned(code.to_owned()) }
+    } else {
+        let mut bytes = [0; CODE_INLINE_CAP];
+        for (dst, byte) in bytes.iter_mut().zip(code.bytes()) {
+            *dst = byte;
+        }
+        Encoding { code: Code::Inline(code.len() as u8, bytes) }
+    }
+}
+
+pub unsafe fn from_malloc_str(ptr: *mut c_char) -> Encoding {
+    let s = CStr::from_ptr(ptr);
+    let bytes = s.to_bytes_with_nul();
+    assert!(str::from_utf8(bytes).is_ok());
+    let buf = MallocBuffer::new(ptr as *mut u8, bytes.len()).unwrap();
+    Encoding { code: Code::Malloc(buf) }
+}
+
+/// Types that have an Objective-C type encoding.
+///
+/// Unsafe because Objective-C will make assumptions about the type (like its
+/// size and alignment) from its encoding, so the implementer must verify that
+/// the encoding is accurate.
+pub unsafe trait Encode {
+    /// Returns the Objective-C type encoding for Self.
+    fn encode() -> Encoding;
+}
+
+macro_rules! encode_impls {
+    ($($t:ty : $s:expr,)*) => ($(
+        unsafe impl Encode for $t {
+            fn encode() -> Encoding { from_static_str($s) }
+        }
+    )*);
+}
+
+encode_impls!(
+    i8: "c",
+    i16: "s",
+    i32: "i",
+    i64: "q",
+    u8: "C",
+    u16: "S",
+    u32: "I",
+    u64: "Q",
+    f32: "f",
+    f64: "d",
+    bool: "B",
+    (): "v",
+    *mut c_char: "*",
+    *const c_char: "r*",
+    *mut c_void: "^v",
+    *const c_void: "r^v",
+    Sel: ":",
+);
+
+unsafe impl Encode for isize {
+    #[cfg(target_pointer_width = "32")]
+    fn encode() -> Encoding { i32::encode() }
+
+    #[cfg(target_pointer_width = "64")]
+    fn encode() -> Encoding { i64::encode() }
+}
+
+unsafe impl Encode for usize {
+    #[cfg(target_pointer_width = "32")]
+    fn encode() -> Encoding { u32::encode() }
+
+    #[cfg(target_pointer_width = "64")]
+    fn encode() -> Encoding { u64::encode() }
+}
+
+macro_rules! encode_message_impl {
+    ($code:expr, $name:ident) => (
+        encode_message_impl!($code, $name,);
+    );
+    ($code:expr, $name:ident, $($t:ident),*) => (
+        unsafe impl<'a $(, $t)*> $crate::Encode for &'a $name<$($t),*> {
+            fn encode() -> Encoding { from_static_str($code) }
+        }
+
+        unsafe impl<'a $(, $t)*> $crate::Encode for &'a mut $name<$($t),*> {
+            fn encode() -> Encoding { from_static_str($code) }
+        }
+
+        unsafe impl<'a $(, $t)*> $crate::Encode for Option<&'a $name<$($t),*>> {
+            fn encode() -> Encoding { from_static_str($code) }
+        }
+
+        unsafe impl<'a $(, $t)*> $crate::Encode for Option<&'a mut $name<$($t),*>> {
+            fn encode() -> Encoding { from_static_str($code) }
+        }
+
+        unsafe impl<$($t),*> $crate::Encode for *const $name<$($t),*> {
+            fn encode() -> Encoding { from_static_str($code) }
+        }
+
+        unsafe impl<$($t),*> $crate::Encode for *mut $name<$($t),*> {
+            fn encode() -> Encoding { from_static_str($code) }
+        }
+    );
+}
+
+encode_message_impl!("@", Object);
+
+encode_message_impl!("#", Class);
+
+/// Types that represent a group of arguments, where each has an Objective-C
+/// type encoding.
+pub trait EncodeArguments {
+    /// The type as which the encodings for Self will be returned.
+    type Encs: AsRef<[Encoding]>;
+
+    /// Returns the Objective-C type encodings for Self.
+    fn encodings() -> Self::Encs;
+}
+
+macro_rules! count_idents {
+    () => (0);
+    ($a:ident) => (1);
+    ($a:ident, $($b:ident),+) => (1 + count_idents!($($b),*));
+}
+
+macro_rules! encode_args_impl {
+    ($($t:ident),*) => (
+        impl<$($t: Encode),*> EncodeArguments for ($($t,)*) {
+            type Encs = [Encoding; count_idents!($($t),*)];
+
+            fn encodings() -> Self::Encs {
+                [
+                    $($t::encode()),*
+                ]
+            }
+        }
+    );
+}
+
+encode_args_impl!();
+encode_args_impl!(A);
+encode_args_impl!(A, B);
+encode_args_impl!(A, B, C);
+encode_args_impl!(A, B, C, D);
+encode_args_impl!(A, B, C, D, E);
+encode_args_impl!(A, B, C, D, E, F);
+encode_args_impl!(A, B, C, D, E, F, G);
+encode_args_impl!(A, B, C, D, E, F, G, H);
+encode_args_impl!(A, B, C, D, E, F, G, H, I);
+encode_args_impl!(A, B, C, D, E, F, G, H, I, J);
+encode_args_impl!(A, B, C, D, E, F, G, H, I, J, K);
+encode_args_impl!(A, B, C, D, E, F, G, H, I, J, K, L);
+
+#[cfg(test)]
+mod tests {
+    use runtime::{Class, Object, Sel};
+    use super::{Encode, Encoding};
+
+    #[test]
+    fn test_encode() {
+        assert!(u32::encode().as_str() == "I");
+        assert!(<()>::encode().as_str() == "v");
+        assert!(<&Object>::encode().as_str() == "@");
+        assert!(<*mut Object>::encode().as_str() == "@");
+        assert!(<&Class>::encode().as_str() == "#");
+        assert!(Sel::encode().as_str() == ":");
+    }
+
+    #[test]
+    fn test_inline_encoding() {
+        let enc = unsafe { Encoding::from_str("C") };
+        assert!(enc.as_str() == "C");
+
+        let enc2 = enc.clone();
+        assert!(enc2 == enc);
+        assert!(enc2.as_str() == "C");
+    }
+
+    #[test]
+    fn test_owned_encoding() {
+        let s = "{Test=CCCCCCCCCCCCCCCCCCCCCCCCC}";
+        let enc = unsafe { Encoding::from_str(s) };
+        assert!(enc.as_str() == s);
+
+        let enc2 = enc.clone();
+        assert!(enc2 == enc);
+        assert!(enc2.as_str() == s);
+    }
+}