auto merge of #17466 : nikomatsakis/rust/oibt, r=pcwalton

Moves the vast majority of builtin bound checking out of type contents and into the trait system.

This is a preliminary step for a lot of follow-on work:

- opt-in builtin types, obviously
- generalized where clauses, because TypeContents has this notion that a type parameter has a single set of builtin kinds, but with where clauses it depends on context
- generalized coherence, because this adds support for recursive trait selection

Unfortunately I wasn't able to completely remove Type Contents from the front-end checking in this PR. It's still used by EUV to decide what gets moved and what doesn't.

r? @pcwalton

Author: bors

mk/crates.mk

@@ -59,6 +59,7 @@ CRATES := $(TARGET_CRATES) $(HOST_CRATES)
 TOOLS := compiletest rustdoc rustc
 
 DEPS_core :=
+DEPS_libc := core
 DEPS_rlibc := core
 DEPS_unicode := core
 DEPS_alloc := core libc native:jemalloc

src/doc/guide-unsafe.md

@@ -466,7 +466,7 @@ fn start(_argc: int, _argv: *const *const u8) -> int {
 // provided by libstd.
 #[lang = "stack_exhausted"] extern fn stack_exhausted() {}
 #[lang = "eh_personality"] extern fn eh_personality() {}
-#[lang = "sized"] trait Sized { }
+#[lang = "fail_fmt"] fn fail_fmt() -> ! { loop {} }
 # // fn main() {} tricked you, rustdoc!
 ```
 
@@ -489,32 +489,28 @@ pub extern fn main(argc: int, argv: *const *const u8) -> int {
 
 #[lang = "stack_exhausted"] extern fn stack_exhausted() {}
 #[lang = "eh_personality"] extern fn eh_personality() {}
-#[lang = "sized"] trait Sized { }
+#[lang = "fail_fmt"] fn fail_fmt() -> ! { loop {} }
 # // fn main() {} tricked you, rustdoc!
 ```
 
 
 The compiler currently makes a few assumptions about symbols which are available
 in the executable to call. Normally these functions are provided by the standard
-xlibrary, but without it you must define your own.
+library, but without it you must define your own.
 
-The first of these two functions, `stack_exhausted`, is invoked whenever stack
+The first of these three functions, `stack_exhausted`, is invoked whenever stack
 overflow is detected.  This function has a number of restrictions about how it
 can be called and what it must do, but if the stack limit register is not being
 maintained then a task always has an "infinite stack" and this function
 shouldn't get triggered.
 
-The second of these two functions, `eh_personality`, is used by the failure
-mechanisms of the compiler. This is often mapped to GCC's personality function
-(see the [libstd implementation](std/rt/unwind/index.html) for more
-information), but crates which do not trigger failure can be assured that this
-function is never called.
-
-The final item in the example is a trait called `Sized`. This a trait
-that represents data of a known static size: it is integral to the
-Rust type system, and so the compiler expects the standard library to
-provide it. Since you are not using the standard library, you have to
-provide it yourself.
+The second of these three functions, `eh_personality`, is used by the
+failure mechanisms of the compiler. This is often mapped to GCC's
+personality function (see the
+[libstd implementation](std/rt/unwind/index.html) for more
+information), but crates which do not trigger failure can be assured
+that this function is never called. The final function, `fail_fmt`, is
+also used by the failure mechanisms of the compiler.
 
 ## Using libcore
 
@@ -694,7 +690,7 @@ fn main(argc: int, argv: *const *const u8) -> int {
 
 #[lang = "stack_exhausted"] extern fn stack_exhausted() {}
 #[lang = "eh_personality"] extern fn eh_personality() {}
-#[lang = "sized"] trait Sized {}
+#[lang = "fail_fmt"] fn fail_fmt() -> ! { loop {} }
 ```
 
 Note the use of `abort`: the `exchange_malloc` lang item is assumed to

src/libcore/kinds.rs

@@ -25,19 +25,19 @@ pub use self::Sync as Share;
 
 /// Types able to be transferred across task boundaries.
 #[lang="send"]
-pub trait Send {
+pub trait Send for Sized? {
     // empty.
 }
 
 /// Types with a constant size known at compile-time.
 #[lang="sized"]
-pub trait Sized {
+pub trait Sized for Sized? {
     // Empty.
 }
 
 /// Types that can be copied by simply copying bits (i.e. `memcpy`).
 #[lang="copy"]
-pub trait Copy {
+pub trait Copy for Sized? {
     // Empty.
 }
 
@@ -87,7 +87,7 @@ pub trait Copy {
 /// reference; not doing this is undefined behaviour (for example,
 /// `transmute`-ing from `&T` to `&mut T` is illegal).
 #[lang="sync"]
-pub trait Sync {
+pub trait Sync for Sized? {
     // Empty
 }
 

src/liblibc/lib.rs

@@ -79,6 +79,8 @@
 #![allow(missing_doc)]
 #![allow(non_snake_case)]
 
+extern crate core;
+
 #[cfg(test)] extern crate std;
 #[cfg(test)] extern crate test;
 #[cfg(test)] extern crate native;

src/librustc/diagnostics.rs

@@ -58,8 +58,6 @@ register_diagnostics!(
     E0039,
     E0040,
     E0041,
-    E0042,
-    E0043,
     E0044,
     E0045,
     E0046,
@@ -92,7 +90,6 @@ register_diagnostics!(
     E0075,
     E0076,
     E0077,
-    E0078,
     E0079,
     E0080,
     E0081,
@@ -130,7 +127,6 @@ register_diagnostics!(
     E0121,
     E0122,
     E0124,
-    E0125,
     E0126,
     E0127,
     E0128,
@@ -147,12 +143,6 @@ register_diagnostics!(
     E0139,
     E0140,
     E0141,
-    E0143,
-    E0144,
-    E0145,
-    E0146,
-    E0148,
-    E0151,
     E0152,
     E0153,
     E0154,

src/librustc/driver/driver.rs

@@ -17,7 +17,7 @@ use lint;
 use llvm::{ContextRef, ModuleRef};
 use metadata::common::LinkMeta;
 use metadata::creader;
-use middle::{trans, stability, kind, ty, typeck, reachable};
+use middle::{trans, stability, ty, typeck, reachable};
 use middle::dependency_format;
 use middle;
 use plugin::load::Plugins;
@@ -462,8 +462,12 @@ pub fn phase_3_run_analysis_passes<'tcx>(sess: Session,
     time(time_passes, "rvalue checking", (), |_|
          middle::check_rvalues::check_crate(&ty_cx, krate));
 
-    time(time_passes, "kind checking", (), |_|
-         kind::check_crate(&ty_cx));
+    // Avoid overwhelming user with errors if type checking failed.
+    // I'm not sure how helpful this is, to be honest, but it avoids a
+    // lot of annoying errors in the compile-fail tests (basically,
+    // lint warnings and so on -- kindck used to do this abort, but
+    // kindck is gone now). -nmatsakis
+    ty_cx.sess.abort_if_errors();
 
     let reachable_map =
         time(time_passes, "reachability checking", (), |_|

src/librustc/lib.rs

@@ -95,7 +95,6 @@ pub mod middle {
     pub mod expr_use_visitor;
     pub mod graph;
     pub mod intrinsicck;
-    pub mod kind;
     pub mod lang_items;
     pub mod liveness;
     pub mod mem_categorization;