---

yaml
---
r: 65505
b: refs/heads/master
c: b8391cc
h: refs/heads/master
i:
  65503: c416e1b
v: v3

Author: bors

[refs]

@@ -1,5 +1,5 @@
 ---
-refs/heads/master: 6e075b6bb6c15e8fa358e08670687e3c94f4565b
+refs/heads/master: b8391ccea0b2e2718a4d4ef999e9f03583c7ddea
 refs/heads/snap-stage1: e33de59e47c5076a89eadeb38f4934f58a3618a6
 refs/heads/snap-stage3: 18e3db7392d2d0697b7e27d6d986139960144d85
 refs/heads/try: 7b78b52e602bb3ea8174f9b2006bff3315f03ef9

trunk/src/librustc/middle/lint.rs

@@ -96,6 +96,7 @@ pub enum lint {
     unnecessary_allocation,
 
     missing_doc,
+    unreachable_code,
 }
 
 pub fn level_to_str(lv: level) -> &'static str {
@@ -273,6 +274,13 @@ static lint_table: &'static [(&'static str, LintSpec)] = &[
         desc: "detects missing documentation for public members",
         default: allow
     }),
+
+    ("unreachable_code",
+     LintSpec {
+        lint: unreachable_code,
+        desc: "detects unreachable code",
+        default: warn
+    }),
 ];
 
 /*

trunk/src/librustc/middle/typeck/check/mod.rs

@@ -81,6 +81,7 @@ use core::prelude::*;
 use middle::const_eval;
 use middle::pat_util::pat_id_map;
 use middle::pat_util;
+use middle::lint::unreachable_code;
 use middle::ty::{FnSig, VariantInfo_};
 use middle::ty::{ty_param_bounds_and_ty, ty_param_substs_and_ty};
 use middle::ty::{substs, param_ty};
@@ -2937,7 +2938,8 @@ pub fn check_block_with_expected(fcx: @mut FnCtxt,
         let mut any_err = false;
         for blk.node.stmts.each |s| {
             check_stmt(fcx, *s);
-            let s_ty = fcx.node_ty(ast_util::stmt_id(*s));
+            let s_id = ast_util::stmt_id(*s);
+            let s_ty = fcx.node_ty(s_id);
             if last_was_bot && !warned && match s.node {
                   ast::stmt_decl(@codemap::spanned { node: ast::decl_local(_),
                                                  _}, _) |
@@ -2946,7 +2948,8 @@ pub fn check_block_with_expected(fcx: @mut FnCtxt,
                   }
                   _ => false
                 } {
-                fcx.ccx.tcx.sess.span_warn(s.span, "unreachable statement");
+                fcx.ccx.tcx.sess.add_lint(unreachable_code, s_id, s.span,
+                                          ~"unreachable statement");
                 warned = true;
             }
             if ty::type_is_bot(s_ty) {

trunk/src/libstd/hashmap.rs

@@ -72,11 +72,12 @@ pub fn linear_map_with_capacity<K:Eq + Hash,V>(
 fn linear_map_with_capacity_and_keys<K:Eq + Hash,V>(
     k0: u64, k1: u64,
     initial_capacity: uint) -> HashMap<K, V> {
+    let cap = uint::max(INITIAL_CAPACITY, initial_capacity);
     HashMap {
         k0: k0, k1: k1,
-        resize_at: resize_at(initial_capacity),
+        resize_at: resize_at(cap),
         size: 0,
-        buckets: vec::from_fn(initial_capacity, |_| None)
+        buckets: vec::from_fn(cap, |_| None)
     }
 }
 
@@ -480,7 +481,8 @@ pub impl<K: Hash + Eq, V> HashMap<K, V> {
     }
 
     fn consume(&mut self, f: &fn(K, V)) {
-        let buckets = replace(&mut self.buckets, ~[]);
+        let buckets = replace(&mut self.buckets,
+                              vec::from_fn(INITIAL_CAPACITY, |_| None));
         self.size = 0;
 
         do vec::consume(buckets) |_, bucket| {
@@ -664,6 +666,12 @@ mod test_map {
     use super::*;
     use uint;
 
+    #[test]
+    fn test_create_capacity_zero() {
+        let mut m = HashMap::with_capacity(0);
+        assert!(m.insert(1, 1));
+    }
+
     #[test]
     fn test_insert() {
         let mut m = HashMap::new();
@@ -771,6 +779,14 @@ mod test_map {
         assert_eq!(m2.get(&2), &3);
     }
 
+    #[test]
+    fn test_consume_still_usable() {
+        let mut m = HashMap::new();
+        assert!(m.insert(1, 2));
+        do m.consume |_, _| {}
+        assert!(m.insert(1, 2));
+    }
+
     #[test]
     fn test_iterate() {
         let mut m = linear_map_with_capacity(4);

trunk/src/libstd/prelude.rs

@@ -45,7 +45,7 @@ pub use path::PosixPath;
 pub use path::WindowsPath;
 pub use ptr::Ptr;
 pub use ascii::{Ascii, AsciiCast, OwnedAsciiCast, AsciiStr};
-pub use str::{StrSlice, OwnedStr};
+pub use str::{StrSlice, OwnedStr, StrUtil};
 pub use from_str::{FromStr};
 pub use to_bytes::IterBytes;
 pub use to_str::{ToStr, ToStrConsume};

trunk/src/libstd/str.rs

@@ -2165,33 +2165,50 @@ pub fn as_bytes_slice<'a>(s: &'a str) -> &'a [u8] {
 }
 
 /**
- * Work with the byte buffer of a string as a null-terminated C string.
- *
- * Allows for unsafe manipulation of strings, which is useful for foreign
- * interop. This is similar to `str::as_buf`, but guarantees null-termination.
- * If the given slice is not already null-terminated, this function will
- * allocate a temporary, copy the slice, null terminate it, and pass
- * that instead.
- *
- * # Example
- *
- * ~~~ {.rust}
- * let s = str::as_c_str("PATH", { |path| libc::getenv(path) });
- * ~~~
+ * A dummy trait to hold all the utility methods that we implement on strings.
  */
-#[inline]
-pub fn as_c_str<T>(s: &str, f: &fn(*libc::c_char) -> T) -> T {
-    do as_buf(s) |buf, len| {
-        // NB: len includes the trailing null.
-        assert!(len > 0);
-        if unsafe { *(ptr::offset(buf,len-1)) != 0 } {
-            as_c_str(to_owned(s), f)
-        } else {
-            f(buf as *libc::c_char)
+pub trait StrUtil {
+    /**
+     * Work with the byte buffer of a string as a null-terminated C string.
+     *
+     * Allows for unsafe manipulation of strings, which is useful for foreign
+     * interop. This is similar to `str::as_buf`, but guarantees null-termination.
+     * If the given slice is not already null-terminated, this function will
+     * allocate a temporary, copy the slice, null terminate it, and pass
+     * that instead.
+     *
+     * # Example
+     *
+     * ~~~ {.rust}
+     * let s = "PATH".as_c_str(|path| libc::getenv(path));
+     * ~~~
+     */
+    fn as_c_str<T>(self, f: &fn(*libc::c_char) -> T) -> T;
+}
+
+impl<'self> StrUtil for &'self str {
+    #[inline]
+    fn as_c_str<T>(self, f: &fn(*libc::c_char) -> T) -> T {
+        do as_buf(self) |buf, len| {
+            // NB: len includes the trailing null.
+            assert!(len > 0);
+            if unsafe { *(ptr::offset(buf,len-1)) != 0 } {
+                to_owned(self).as_c_str(f)
+            } else {
+                f(buf as *libc::c_char)
+            }
         }
     }
 }
 
+/**
+ * Deprecated. Use the `as_c_str` method on strings instead.
+ */
+#[inline(always)]
+pub fn as_c_str<T>(s: &str, f: &fn(*libc::c_char) -> T) -> T {
+    s.as_c_str(f)
+}
+
 /**
  * Work with the byte buffer and length of a slice.
  *

trunk/src/libstd/vec.rs

@@ -149,8 +149,7 @@ pub fn from_fn<T>(n_elts: uint, op: old_iter::InitOp<T>) -> ~[T] {
         do as_mut_buf(v) |p, _len| {
             let mut i: uint = 0u;
             while i < n_elts {
-                intrinsics::move_val_init(&mut(*ptr::mut_offset(p, i)),
-                                          op(i));
+                intrinsics::move_val_init(&mut(*ptr::mut_offset(p, i)), op(i));
                 i += 1u;
             }
         }
@@ -166,7 +165,20 @@ pub fn from_fn<T>(n_elts: uint, op: old_iter::InitOp<T>) -> ~[T] {
  * to the value `t`.
  */
 pub fn from_elem<T:Copy>(n_elts: uint, t: T) -> ~[T] {
-    from_fn(n_elts, |_i| copy t)
+    // hack: manually inline from_fn for 2x plus speedup (sadly very important, from_elem is a
+    // bottleneck in borrowck!)
+    unsafe {
+        let mut v = with_capacity(n_elts);
+        do as_mut_buf(v) |p, _len| {
+            let mut i = 0u;
+            while i < n_elts {
+                intrinsics::move_val_init(&mut(*ptr::mut_offset(p, i)), copy t);
+                i += 1u;
+            }
+        }
+        raw::set_len(&mut v, n_elts);
+        v
+    }
 }
 
 /// Creates a new unique vector with the same contents as the slice