auto merge of #5252 : nikomatsakis/rust/issue-5087-make-trait-not-imp…

…l-self, r=pcwalton

Two changes:

- The first fixes an inconsistency in coherence whereby extension methods were added to the inherent methods table, but only in cross-crate scenarios.  This causes some minor fallout in tests and so forth.  In one case (comm) I added inherent and trait methods so as to avoid the need to import traits like `GenericPort` just to use a port.

- The second makes objects not implement the associated trait, as discussed in #5087.

r? @pcwalton

src/libcore/comm.rs

@@ -104,64 +104,98 @@ pub fn stream<T:Owned>() -> (Port<T>, Chan<T>) {
     (Port_(Port_ { endp: Some(s) }), Chan_(Chan_{ endp: Some(c) }))
 }
 
+// Add an inherent method so that imports of GenericChan are not
+// required.
+#[cfg(stage1)]
+#[cfg(stage2)]
+pub impl<T: Owned> Chan<T> {
+    fn send(&self, x: T) { chan_send(self, x) }
+    fn try_send(&self, x: T) -> bool { chan_try_send(self, x) }
+}
+
 impl<T: Owned> GenericChan<T> for Chan<T> {
-    fn send(&self, x: T) {
-        let mut endp = None;
-        endp <-> self.endp;
-        self.endp = Some(
-            streamp::client::data(unwrap(endp), x))
-    }
+    fn send(&self, x: T) { chan_send(self, x) }
 }
 
-impl<T: Owned> GenericSmartChan<T> for Chan<T> {
+#[inline(always)]
+fn chan_send<T:Owned>(self: &Chan<T>, x: T) {
+    let mut endp = None;
+    endp <-> self.endp;
+    self.endp = Some(
+        streamp::client::data(unwrap(endp), x))
+}
 
+impl<T: Owned> GenericSmartChan<T> for Chan<T> {
     fn try_send(&self, x: T) -> bool {
-        let mut endp = None;
-        endp <-> self.endp;
-        match streamp::client::try_data(unwrap(endp), x) {
-            Some(next) => {
-                self.endp = Some(next);
-                true
-            }
-            None => false
-        }
+        chan_try_send(self, x)
     }
 }
 
-impl<T: Owned> GenericPort<T> for Port<T> {
-    fn recv(&self) -> T {
-        let mut endp = None;
-        endp <-> self.endp;
-        let streamp::data(x, endp) = recv(unwrap(endp));
-        self.endp = Some(endp);
-        x
+#[inline(always)]
+fn chan_try_send<T:Owned>(self: &Chan<T>, x: T) -> bool {
+    let mut endp = None;
+    endp <-> self.endp;
+    match streamp::client::try_data(unwrap(endp), x) {
+        Some(next) => {
+            self.endp = Some(next);
+            true
+        }
+        None => false
     }
+}
 
-    fn try_recv(&self) -> Option<T> {
-        let mut endp = None;
-        endp <-> self.endp;
-        match try_recv(unwrap(endp)) {
-          Some(streamp::data(x, endp)) => {
+// Use an inherent impl so that imports are not required:
+#[cfg(stage1)]
+#[cfg(stage2)]
+pub impl<T: Owned> Port<T> {
+    fn recv(&self) -> T { port_recv(self) }
+    fn try_recv(&self) -> Option<T> { port_try_recv(self) }
+    pure fn peek(&self) -> bool { port_peek(self) }
+}
+
+impl<T: Owned> GenericPort<T> for Port<T> {
+    // These two calls will prefer the inherent versions above:
+    fn recv(&self) -> T { port_recv(self) }
+    fn try_recv(&self) -> Option<T> { port_try_recv(self) }
+}
+
+#[inline(always)]
+fn port_recv<T:Owned>(self: &Port<T>) -> T {
+    let mut endp = None;
+    endp <-> self.endp;
+    let streamp::data(x, endp) = recv(unwrap(endp));
+    self.endp = Some(endp);
+    x
+}
+
+#[inline(always)]
+fn port_try_recv<T:Owned>(self: &Port<T>) -> Option<T> {
+    let mut endp = None;
+    endp <-> self.endp;
+    match try_recv(unwrap(endp)) {
+        Some(streamp::data(x, endp)) => {
             self.endp = Some(endp);
             Some(x)
-          }
-          None => None
         }
+        None => None
     }
 }
 
 impl<T: Owned> Peekable<T> for Port<T> {
-    pure fn peek(&self) -> bool {
-        unsafe {
-            let mut endp = None;
-            endp <-> self.endp;
-            let peek = match &endp {
-              &Some(ref endp) => peek(endp),
-              &None => fail!(~"peeking empty stream")
-            };
-            self.endp <-> endp;
-            peek
-        }
+    pure fn peek(&self) -> bool { port_peek(self) }
+}
+
+#[inline(always)]
+pure fn port_peek<T:Owned>(self: &Port<T>) -> bool {
+    unsafe {
+        let mut endp = None;
+        endp <-> self.endp;
+        let peek = match &endp {
+            &Some(ref endp) => peek(endp),
+            &None => fail!(~"peeking empty stream")
+        };
+        self.endp <-> endp;
+        peek
     }
 }
 
@@ -187,8 +221,16 @@ pub fn PortSet<T: Owned>() -> PortSet<T>{
     }
 }
 
-pub impl<T: Owned> PortSet<T> {
+// Use an inherent impl so that imports are not required:
+#[cfg(stage1)]
+#[cfg(stage2)]
+pub impl<T:Owned> PortSet<T> {
+    fn recv(&self) -> T { port_set_recv(self) }
+    fn try_recv(&self) -> Option<T> { port_set_try_recv(self) }
+    pure fn peek(&self) -> bool { port_set_peek(self) }
+}
 
+pub impl<T: Owned> PortSet<T> {
     fn add(&self, port: Port<T>) {
         self.ports.push(port)
     }
@@ -200,69 +242,89 @@ pub impl<T: Owned> PortSet<T> {
     }
 }
 
-impl<T: Owned> GenericPort<T> for PortSet<T> {
-
-    fn try_recv(&self) -> Option<T> {
-        let mut result = None;
-        // we have to swap the ports array so we aren't borrowing
-        // aliasable mutable memory.
-        let mut ports = ~[];
-        ports <-> self.ports;
-        while result.is_none() && ports.len() > 0 {
-            let i = wait_many(ports);
-            match ports[i].try_recv() {
-                Some(m) => {
-                  result = Some(m);
-                }
-                None => {
-                    // Remove this port.
-                    let _ = ports.swap_remove(i);
-                }
+impl<T:Owned> GenericPort<T> for PortSet<T> {
+    fn try_recv(&self) -> Option<T> { port_set_try_recv(self) }
+    fn recv(&self) -> T { port_set_recv(self) }
+}
+
+#[inline(always)]
+fn port_set_recv<T:Owned>(self: &PortSet<T>) -> T {
+    port_set_try_recv(self).expect("port_set: endpoints closed")
+}
+
+#[inline(always)]
+fn port_set_try_recv<T:Owned>(self: &PortSet<T>) -> Option<T> {
+    let mut result = None;
+    // we have to swap the ports array so we aren't borrowing
+    // aliasable mutable memory.
+    let mut ports = ~[];
+    ports <-> self.ports;
+    while result.is_none() && ports.len() > 0 {
+        let i = wait_many(ports);
+        match ports[i].try_recv() {
+            Some(m) => {
+                result = Some(m);
+            }
+            None => {
+                // Remove this port.
+                let _ = ports.swap_remove(i);
             }
         }
-        ports <-> self.ports;
-        result
     }
-
-    fn recv(&self) -> T {
-        self.try_recv().expect("port_set: endpoints closed")
-    }
-
+    ports <-> self.ports;
+    result
 }
 
 impl<T: Owned> Peekable<T> for PortSet<T> {
-    pure fn peek(&self) -> bool {
-        // It'd be nice to use self.port.each, but that version isn't
-        // pure.
-        for vec::each(self.ports) |p| {
-            if p.peek() { return true }
-        }
-        false
+    pure fn peek(&self) -> bool { port_set_peek(self) }
+}
+
+#[inline(always)]
+pure fn port_set_peek<T:Owned>(self: &PortSet<T>) -> bool {
+    // It'd be nice to use self.port.each, but that version isn't
+    // pure.
+    for vec::each(self.ports) |p| {
+        if p.peek() { return true }
     }
+    false
 }
 
+
 /// A channel that can be shared between many senders.
 pub type SharedChan<T> = unstable::Exclusive<Chan<T>>;
 
+#[cfg(stage1)]
+#[cfg(stage2)]
+pub impl<T: Owned> SharedChan<T> {
+    fn send(&self, x: T) { shared_chan_send(self, x) }
+    fn try_send(&self, x: T) -> bool { shared_chan_try_send(self, x) }
+}
+
 impl<T: Owned> GenericChan<T> for SharedChan<T> {
-    fn send(&self, x: T) {
-        let mut xx = Some(x);
-        do self.with_imm |chan| {
-            let mut x = None;
-            x <-> xx;
-            chan.send(option::unwrap(x))
-        }
+    fn send(&self, x: T) { shared_chan_send(self, x) }
+}
+
+#[inline(always)]
+fn shared_chan_send<T:Owned>(self: &SharedChan<T>, x: T) {
+    let mut xx = Some(x);
+    do self.with_imm |chan| {
+        let mut x = None;
+        x <-> xx;
+        chan.send(option::unwrap(x))
     }
 }
 
 impl<T: Owned> GenericSmartChan<T> for SharedChan<T> {
-    fn try_send(&self, x: T) -> bool {
-        let mut xx = Some(x);
-        do self.with_imm |chan| {
-            let mut x = None;
-            x <-> xx;
-            chan.try_send(option::unwrap(x))
-        }
+    fn try_send(&self, x: T) -> bool { shared_chan_try_send(self, x) }
+}
+
+#[inline(always)]
+fn shared_chan_try_send<T:Owned>(self: &SharedChan<T>, x: T) -> bool {
+    let mut xx = Some(x);
+    do self.with_imm |chan| {
+        let mut x = None;
+        x <-> xx;
+        chan.try_send(option::unwrap(x))
     }
 }
 

src/libcore/io.rs

@@ -69,6 +69,26 @@ pub trait Reader {
     fn tell(&self) -> uint;
 }
 
+#[cfg(stage1)]
+#[cfg(stage2)]
+impl Reader for @Reader {
+    fn read(&self, bytes: &mut [u8], len: uint) -> uint {
+        self.read(bytes, len)
+    }
+    fn read_byte(&self) -> int {
+        self.read_byte()
+    }
+    fn eof(&self) -> bool {
+        self.eof()
+    }
+    fn seek(&self, position: int, style: SeekStyle) {
+        self.seek(position, style)
+    }
+    fn tell(&self) -> uint {
+        self.tell()
+    }
+}
+
 /// Generic utility functions defined on readers.
 pub trait ReaderUtil {
 
@@ -631,6 +651,16 @@ pub trait Writer {
     fn get_type(&self) -> WriterType;
 }
 
+#[cfg(stage1)]
+#[cfg(stage2)]
+impl Writer for @Writer {
+    fn write(&self, v: &[const u8]) { self.write(v) }
+    fn seek(&self, a: int, b: SeekStyle) { self.seek(a, b) }
+    fn tell(&self) -> uint { self.tell() }
+    fn flush(&self) -> int { self.flush() }
+    fn get_type(&self) -> WriterType { self.get_type() }
+}
+
 impl<W:Writer,C> Writer for Wrapper<W, C> {
     fn write(&self, bs: &[const u8]) { self.base.write(bs); }
     fn seek(&self, off: int, style: SeekStyle) { self.base.seek(off, style); }
@@ -1067,8 +1097,8 @@ pub fn buffered_file_writer(path: &Path) -> Result<Writer, ~str> {
 // FIXME (#2004) it would be great if this could be a const
 // FIXME (#2004) why are these different from the way stdin() is
 // implemented?
-pub fn stdout() -> Writer { fd_writer(libc::STDOUT_FILENO as c_int, false) }
-pub fn stderr() -> Writer { fd_writer(libc::STDERR_FILENO as c_int, false) }
+pub fn stdout() -> @Writer { fd_writer(libc::STDOUT_FILENO as c_int, false) }
+pub fn stderr() -> @Writer { fd_writer(libc::STDERR_FILENO as c_int, false) }
 
 pub fn print(s: &str) { stdout().write_str(s); }
 pub fn println(s: &str) { stdout().write_line(s); }

src/librustc/back/link.rs

@@ -23,6 +23,7 @@ use middle::ty;
 use util::ppaux;
 
 use core::char;
+use core::hash::Streaming;
 use core::hash;
 use core::io::{Writer, WriterUtil};
 use core::libc::{c_int, c_uint, c_char};

src/librustc/metadata/encoder.rs

@@ -26,7 +26,7 @@ use core::dvec;
 use core::flate;
 use core::hash::{Hash, HashUtil};
 use core::int;
-use core::io::WriterUtil;
+use core::io::{Writer, WriterUtil};
 use core::io;
 use core::str;
 use core::to_bytes::IterBytes;