---

yaml
---
r: 81693
b: refs/heads/master
c: fadc6cc
h: refs/heads/master
i:
  81691: ad7e073
v: v3

Author: Evgeny Sologubov

[refs]

@@ -1,5 +1,5 @@
 ---
-refs/heads/master: 755f6229da1d436f4cb23fffea644ba13291b434
+refs/heads/master: fadc6cc4b006d0eb6250afb899f10f8b67ad546d
 refs/heads/snap-stage1: e33de59e47c5076a89eadeb38f4934f58a3618a6
 refs/heads/snap-stage3: 6c08cc2db4f98e9f07ae7d50338396c4123c2f0a
 refs/heads/try: 70152ff55722878cde684ee6462c14c65f2c4729

trunk/RELEASES.txt

@@ -1,148 +1,3 @@
-Version 0.8 (October 2013)
---------------------------
-
-   * ~2100 changes, numerous bugfixes
-
-   * Language
-      * The `for` loop syntax has changed to work with the `Iterator` trait.
-      * At long last, unwinding works on Windows.
-      * Default methods definitely mostly work.
-      * Many trait inheritance bugs fixed.
-      * Owned and borrowed trait objects work more reliably.
-      * `copy` is no longer a keyword. It has been replaced by the `Clone` trait.
-      * rustc no longer emits code for the `debug!` macro unless it is passed
-        `--cfg debug`
-      * mod.rs is now "blessed". When loading `mod foo;`, rustc will now look
-        for foo.rs, then foo/mod.rs, and will generate an error when both are
-        present.
-      * Strings no longer contain trailing nulls. The new `std::c_str` module
-        provides new mechanisms for converting to C strings.
-      * The type of foreign functions is now `extern "C" fn` instead of `*u8'.
-      * The FFI has been overhauled such that foreign functions are called directly,
-        instead of through a stack-switching wrapper.
-      * Calling a foreign function must be done through a Rust function with the
-        `#[fixed_stack_segment]` attribute.
-      * The `externfn!` macro can be used to declare both a foreign function and
-        a `#[fixed_stack_segment]` wrapper at once.
-      * `pub` and `priv` modifiers on `extern` blocks are no longer parsed.
-      * `unsafe` is no longer allowed on extern fns - they are all unsafe.
-      * `priv` is disallowed everywhere except for struct fields and enum variants.
-      * `&T` (besides `&'static T`) is no longer allowed in `@T`.
-      * `ref` bindings in irrefutable patterns work correctly now.
-      * `char` is now prevented from containing invalid code points.
-      * Casting to `bool` is no longer allowed.
-      * `yield` is a reserved keyword.
-      * `typeof` is a reserved keyword.
-      * Crates may be imported by URL with `extern mod foo = "url";`.
-      * Explicit enum discriminants may be given as uints as in `enum E { V = 0u }`
-      * Static vectors can be initialized with repeating elements,
-        e.g. `static foo: [u8, .. 100]: [0, .. 100];`.
-      * Static structs can be initialized with functional record update,
-        e.g. `static foo: Foo = Foo { a: 5, .. bar };`.
-      * `cfg!` can be used to conditionally execute code based on the crate
-        configuration, similarly to `#[cfg(...)]`.
-      * The `unnecessary_qualification` lint detects unneeded module
-        prefixes (default: allow).
-      * Arithmetic operations have been implemented on the SIMD types in
-        `std::unstable::simd`.
-      * Exchange allocation headers were removed, reducing memory usage.
-      * `format!` implements a completely new, extensible, and higher-performance
-        string formatting system. It will replace `fmt!`.
-      * `print!` and `println!` write formatted strings (using the `format!`
-        extension) to stdout.
-      * `write!` and `writeln!` write formatted strings (using the `format!`
-        extension) to the new Writers in `std::rt::io`.
-      * The library section in which a function or static is placed may
-        be specified with `#[link_section = "..."]`.
-      * The `proto!` syntax extension for defining bounded message protocols
-        was removed.
-      * `macro_rules!` is hygenic for `let` declarations.
-      * The `#[export_name]` attribute specifies the name of a symbol.
-      * `unreachable!` can be used to indicate unreachable code, and fails
-        if executed.
-
-   * Libraries
-      * std: Transitioned to the new runtime, written in Rust.
-      * std: Added an experimental I/O library, `rt::io`, based on the new
-        runtime.
-      * std: A new generic `range` function was added to the prelude, replacing
-        `uint::range` and friends.
-      * std: `range_rev` no longer exists. Since range is an iterator it can be
-        reversed with `range(lo, hi).invert()`.
-      * std: The `chain` method on option renamed to `and_then`; `unwrap_or_default`
-        renamed to `unwrap_or`.
-      * std: The `iterator` module was renamed to `iter`.
-      * std: Integral types now support the `checked_add`, `checked_sub`, and
-        `checked_mul` operations for detecting overflow.
-      * std: Many methods in `str`, `vec`, `option, `result` were renamed for
-        consistency.
-      * std: Methods are standardizing on conventions for casting methods:
-        `to_foo` for copying, `into_foo` for moving, `as_foo` for temporary
-        and cheap casts.
-      * std: The `CString` type in `c_str` provides new ways to convert to and
-        from C strings.
-      * std: `DoubleEndedIterator` can yield elements in two directions.
-      * std: The `mut_split` method on vectors partitions an `&mut [T]` into
-        two splices.
-      * std: `str::from_bytes` renamed to `str::from_utf8`.
-      * std: `pop_opt` and `shift_opt` methods added to vectors.
-      * std: The task-local data interface no longer uses @, and keys are
-        no longer function pointers.
-      * std: The `swap_unwrap` method of `Option` renamed to `take_unwrap`.
-      * std: Added `SharedPort` to `comm`.
-      * std: `Eq` has a default method for `ne`; only `eq` is required
-        in implementations.
-      * std: `Ord` has default methods for `le`, `gt` and `le`; only `lt`
-        is required in implementations.
-      * std: `is_utf8` performance is improved, impacting many string functions.
-      * std: `os::MemoryMap` provides cross-platform mmap.
-      * std: `ptr::offset` is now unsafe, but also more optimized. Offsets that
-        are not 'in-bounds' are considered undefined.
-      * std: Many freestanding functions in `vec` removed in favor of methods.
-      * std: Many freestanding functions on scalar types removed in favor of
-        methods.
-      * std: Many options to task builders were removed since they don't make
-        sense in the new scheduler design.
-      * std: More containers implement `FromIterator` so can be created by the
-        `collect` method.
-      * std: More complete atomic types in `unstable::atomics`.
-      * std: `comm::PortSet` removed.
-      * std: Mutating methods in the `Set` and `Map` traits have been moved into
-        the `MutableSet` and `MutableMap` traits. `Container::is_empty`,
-        `Map::contains_key`, `MutableMap::insert`, and `MutableMap::remove` have
-        default implementations.
-      * extra: `dlist`, the doubly-linked list was modernized.
-      * extra: Added a `hex` module with `ToHex` and `FromHex` traits.
-      * extra: Added `glob` module, replacing `std::os::glob`.
-      * extra: `rope` was removed.
-      * extra: `deque` was renamed to `ringbuf`. `RingBuf` implements `Deque`.
-      * extra: `net`, and `timer` were removed. The experimental replacements
-        are `std::rt::io::net` and `std::rt::io::timer`.
-      * extra: Iterators implemented for `SmallIntMap`.
-      * extra: Iterators implemented for `Bitv` and `BitvSet`.
-      * extra: `SmallIntSet` removed. Use `BitvSet`.
-      * extra: Performance of JSON parsing greatly improved.
-      * extra: `semver` updated to SemVer 2.0.0.
-      * extra: `term` handles more terminals correctly.
-      * extra: `dbg` module removed.
-
-   * Other
-      * rustc's debug info generation (`-Z debug-info`) is greatly improved.
-      * rustc accepts `--target-cpu` to compile to a specific CPU architecture,
-        similarly to gcc's `--march` flag.
-      * rustpkg has received many improvements.
-      * rustpkg supports git tags as package IDs.
-      * rustpkg builds into target-specific directories so it can be used for
-        cross-compiling.
-      * The number of concurrent test tasks is controlled by the environment
-        variable RUST_TEST_TASKS.
-      * The test harness can now report metrics for benchmarks.
-      * All tools have man pages.
-      * Programs compiled with `--test` now support the `-h` and `--help` flags.
-      * The runtime uses jemalloc for allocations.
-      * Segmented stacks are temporarily disabled as part of the transition to
-        the new runtime. Stack overflows are possible!
-
 Version 0.7 (July 2013)
 -----------------------
 

trunk/src/librustc/middle/trans/expr.rs

@@ -313,6 +313,36 @@ pub fn trans_to_datum(bcx: @mut Block, expr: @ast::Expr) -> DatumBlock {
         let target_obj_ty = expr_ty_adjusted(bcx, expr);
         debug!("auto_borrow_obj(target=%s)",
                target_obj_ty.repr(tcx));
+
+        // Extract source store information
+        let (source_store, source_mutbl) = match ty::get(source_datum.ty).sty {
+            ty::ty_trait(_, _, s, m, _) => (s, m),
+            _ => {
+                bcx.sess().span_bug(
+                    expr.span,
+                    fmt!("auto_borrow_trait_obj expected a trait, found %s",
+                         source_datum.ty.repr(bcx.tcx())));
+            }
+        };
+
+        // check if any borrowing is really needed or we could reuse the source_datum instead
+        match ty::get(target_obj_ty).sty {
+            ty::ty_trait(_, _, ty::RegionTraitStore(target_scope), target_mutbl, _) => {
+                if target_mutbl == ast::MutImmutable && target_mutbl == source_mutbl {
+                    match source_store {
+                        ty::RegionTraitStore(source_scope) => {
+                            if tcx.region_maps.is_subregion_of(target_scope, source_scope) {
+                                return DatumBlock { bcx: bcx, datum: source_datum };
+                            }
+                        },
+                        _ => {}
+
+                    };
+                }
+            },
+            _ => {}
+        }
+
         let scratch = scratch_datum(bcx, target_obj_ty,
                                     "__auto_borrow_obj", false);
 
@@ -331,15 +361,6 @@ pub fn trans_to_datum(bcx: @mut Block, expr: @ast::Expr) -> DatumBlock {
         // ~T, or &T, depending on source_obj_ty.
         let source_data_ptr = GEPi(bcx, source_llval, [0u, abi::trt_field_box]);
         let source_data = Load(bcx, source_data_ptr); // always a ptr
-        let (source_store, source_mutbl) = match ty::get(source_datum.ty).sty {
-            ty::ty_trait(_, _, s, m, _) => (s, m),
-            _ => {
-                bcx.sess().span_bug(
-                    expr.span,
-                    fmt!("auto_borrow_trait_obj expected a trait, found %s",
-                         source_datum.ty.repr(bcx.tcx())));
-            }
-        };
         let target_data = match source_store {
             ty::BoxTraitStore(*) => {
                 // For deref of @T or @mut T, create a dummy datum and

trunk/src/librustc/middle/trans/meth.rs

@@ -434,13 +434,22 @@ pub fn trans_trait_callee(bcx: @mut Block,
     let _icx = push_ctxt("impl::trans_trait_callee");
     let mut bcx = bcx;
 
+    // make a local copy for trait if needed
     let self_ty = expr_ty_adjusted(bcx, self_expr);
-    let self_scratch = scratch_datum(bcx, self_ty, "__trait_callee", false);
-    bcx = expr::trans_into(bcx, self_expr, expr::SaveIn(self_scratch.val));
+    let self_scratch = match ty::get(self_ty).sty {
+        ty::ty_trait(_, _, ty::RegionTraitStore(*), _, _) => {
+            unpack_datum!(bcx, expr::trans_to_datum(bcx, self_expr))
+        }
+        _ => {
+            let d = scratch_datum(bcx, self_ty, "__trait_callee", false);
+            bcx = expr::trans_into(bcx, self_expr, expr::SaveIn(d.val));
+            // Arrange a temporary cleanup for the object in case something
+            // should go wrong before the method is actually *invoked*.
+            d.add_clean(bcx);
+            d
+        }
+    };
 
-    // Arrange a temporary cleanup for the object in case something
-    // should go wrong before the method is actually *invoked*.
-    self_scratch.add_clean(bcx);
 
     let callee_ty = node_id_type(bcx, callee_id);
     trans_trait_callee_from_llval(bcx,

trunk/src/librustc/middle/trans/type_.rs

@@ -278,23 +278,12 @@ impl Type {
 
     pub fn opaque_trait(ctx: &CrateContext, store: ty::TraitStore) -> Type {
         let tydesc_ptr = ctx.tydesc_type.ptr_to();
-        match store {
-            ty::BoxTraitStore => {
-                Type::struct_(
-                    [ tydesc_ptr, Type::opaque_box(ctx).ptr_to() ],
-                false)
-            }
-            ty::UniqTraitStore => {
-                Type::struct_(
-                    [ tydesc_ptr, Type::unique(ctx, &Type::i8()).ptr_to()],
-                false)
-            }
-            ty::RegionTraitStore(*) => {
-                Type::struct_(
-                    [ tydesc_ptr, Type::i8().ptr_to() ],
-                false)
-            }
-        }
+        let box_ty = match store {
+            ty::BoxTraitStore => Type::opaque_box(ctx),
+            ty::UniqTraitStore => Type::unique(ctx, &Type::i8()),
+            ty::RegionTraitStore(*) => Type::i8()
+        };
+        Type::struct_([tydesc_ptr, box_ty.ptr_to()], false)
     }
 
     pub fn kind(&self) -> TypeKind {

trunk/src/libstd/option.rs

@@ -467,14 +467,23 @@ impl<T: Default> Option<T> {
             None => Default::default()
         }
     }
+
+    /// Returns self or `Some`-wrapped default value
+    #[inline]
+    pub fn or_default(self) -> Option<T> {
+        match self {
+            None => Some(Default::default()),
+            x => x,
+        }
+    }
 }
 
 impl<T> Default for Option<T> {
     #[inline]
     fn default() -> Option<T> { None }
 }
 
-impl<T: Zero> Option<T> {
+impl<T:Zero> Option<T> {
     /// Returns the contained value or zero (for this type)
     #[inline]
     pub fn unwrap_or_zero(self) -> T {
@@ -483,6 +492,15 @@ impl<T: Zero> Option<T> {
             None => Zero::zero()
         }
     }
+
+    /// Returns self or `Some`-wrapped zero value
+    #[inline]
+    pub fn or_zero(self) -> Option<T> {
+        match self {
+            None => Some(Zero::zero()),
+            x => x
+        }
+    }
 }
 
 /// An iterator that yields either one or zero elements

trunk/src/libsyntax/ext/deriving/default.rs

@@ -47,7 +47,9 @@ fn default_substructure(cx: @ExtCtxt, span: Span, substr: &Substructure) -> @Exp
         cx.ident_of("Default"),
         cx.ident_of("default")
     ];
-    let default_call = cx.expr_call_global(span, default_ident.clone(), ~[]);
+    let default_call = || {
+        cx.expr_call_global(span, default_ident.clone(), ~[])
+    };
 
     return match *substr.fields {
         StaticStruct(_, ref summary) => {
@@ -56,13 +58,13 @@ fn default_substructure(cx: @ExtCtxt, span: Span, substr: &Substructure) -> @Exp
                     if count == 0 {
                         cx.expr_ident(span, substr.type_ident)
                     } else {
-                        let exprs = vec::from_elem(count, default_call);
+                        let exprs = vec::from_fn(count, |_| default_call());
                         cx.expr_call_ident(span, substr.type_ident, exprs)
                     }
                 }
                 Right(ref fields) => {
                     let default_fields = do fields.map |ident| {
-                        cx.field_imm(span, *ident, default_call)
+                        cx.field_imm(span, *ident, default_call())
                     };
                     cx.expr_struct_ident(span, substr.type_ident, default_fields)
                 }

trunk/src/libsyntax/ext/deriving/zero.rs

@@ -62,7 +62,9 @@ fn zero_substructure(cx: @ExtCtxt, span: Span, substr: &Substructure) -> @Expr {
         cx.ident_of("Zero"),
         cx.ident_of("zero")
     ];
-    let zero_call = cx.expr_call_global(span, zero_ident.clone(), ~[]);
+    let zero_call = || {
+        cx.expr_call_global(span, zero_ident.clone(), ~[])
+    };
 
     return match *substr.fields {
         StaticStruct(_, ref summary) => {
@@ -71,13 +73,13 @@ fn zero_substructure(cx: @ExtCtxt, span: Span, substr: &Substructure) -> @Expr {
                     if count == 0 {
                         cx.expr_ident(span, substr.type_ident)
                     } else {
-                        let exprs = vec::from_elem(count, zero_call);
+                        let exprs = vec::from_fn(count, |_| zero_call());
                         cx.expr_call_ident(span, substr.type_ident, exprs)
                     }
                 }
                 Right(ref fields) => {
                     let zero_fields = do fields.map |ident| {
-                        cx.field_imm(span, *ident, zero_call)
+                        cx.field_imm(span, *ident, zero_call())
                     };
                     cx.expr_struct_ident(span, substr.type_ident, zero_fields)
                 }

trunk/src/libsyntax/ext/format.rs

@@ -76,7 +76,6 @@ impl Context {
                 self.ecx.span_err(sp, "expected token: `,`");
                 return (extra, None);
             }
-            if *p.token == token::EOF { break } // accept trailing commas
             if named || (token::is_ident(p.token) &&
                          p.look_ahead(1, |t| *t == token::EQ)) {
                 named = true;

trunk/src/test/run-pass/core-run-destroy.rs

@@ -55,6 +55,7 @@ fn test_destroy_actually_kills(force: bool) {
 
     #[cfg(windows)]
     fn process_exists(pid: libc::pid_t) -> bool {
+        #[fixed_stack_segment];
 
         use std::libc::types::os::arch::extra::DWORD;
         use std::libc::funcs::extra::kernel32::{CloseHandle, GetExitCodeProcess, OpenProcess};

trunk/src/test/run-pass/ifmt.rs

@@ -243,10 +243,6 @@ pub fn main() {
     }
 
     test_format_args();
-
-    // test that trailing commas are acceptable
-    format!("{}", "test",);
-    format!("{foo}", foo="test",);
 }
 
 // Basic test to make sure that we can invoke the `write!` macro with an