diff --git a/src/bootstrap/check.rs b/src/bootstrap/check.rs
index 6e276f44668f7..06edbd8e9eec3 100644
--- a/src/bootstrap/check.rs
+++ b/src/bootstrap/check.rs
@@ -246,8 +246,11 @@ impl Step for Rls {
let compiler = builder.compiler(stage, host);
builder.ensure(tool::Rls { compiler, target: self.host });
- let mut cargo = builder.cargo(compiler, Mode::Tool, host, "test");
- cargo.arg("--manifest-path").arg(build.src.join("src/tools/rls/Cargo.toml"));
+ let mut cargo = tool::prepare_tool_cargo(builder,
+ compiler,
+ host,
+ "test",
+ "src/tools/rls");
// Don't build tests dynamically, just a pain to work with
cargo.env("RUSTC_NO_PREFER_DYNAMIC", "1");
@@ -291,8 +294,11 @@ impl Step for Rustfmt {
let compiler = builder.compiler(stage, host);
builder.ensure(tool::Rustfmt { compiler, target: self.host });
- let mut cargo = builder.cargo(compiler, Mode::Tool, host, "test");
- cargo.arg("--manifest-path").arg(build.src.join("src/tools/rustfmt/Cargo.toml"));
+ let mut cargo = tool::prepare_tool_cargo(builder,
+ compiler,
+ host,
+ "test",
+ "src/tools/rustfmt");
// Don't build tests dynamically, just a pain to work with
cargo.env("RUSTC_NO_PREFER_DYNAMIC", "1");
diff --git a/src/bootstrap/native.rs b/src/bootstrap/native.rs
index c4e8063031520..2c8e5004041da 100644
--- a/src/bootstrap/native.rs
+++ b/src/bootstrap/native.rs
@@ -352,34 +352,51 @@ impl Step for Openssl {
// originally from https://www.openssl.org/source/...
let url = format!("https://s3-us-west-1.amazonaws.com/rust-lang-ci2/rust-ci-mirror/{}",
name);
- let mut ok = false;
+ let mut last_error = None;
for _ in 0..3 {
let status = Command::new("curl")
.arg("-o").arg(&tmp)
+ .arg("-f") // make curl fail if the URL does not return HTTP 200
.arg(&url)
.status()
.expect("failed to spawn curl");
- if status.success() {
- ok = true;
- break
+
+ // Retry if download failed.
+ if !status.success() {
+ last_error = Some(status.to_string());
+ continue;
}
+
+ // Ensure the hash is correct.
+ let mut shasum = if target.contains("apple") || build.build.contains("netbsd") {
+ let mut cmd = Command::new("shasum");
+ cmd.arg("-a").arg("256");
+ cmd
+ } else {
+ Command::new("sha256sum")
+ };
+ let output = output(&mut shasum.arg(&tmp));
+ let found = output.split_whitespace().next().unwrap();
+
+ // If the hash is wrong, probably the download is incomplete or S3 served an error
+ // page. In any case, retry.
+ if found != OPENSSL_SHA256 {
+ last_error = Some(format!(
+ "downloaded openssl sha256 different\n\
+ expected: {}\n\
+ found: {}\n",
+ OPENSSL_SHA256,
+ found
+ ));
+ continue;
+ }
+
+ // Everything is fine, so exit the retry loop.
+ last_error = None;
+ break;
}
- if !ok {
- panic!("failed to download openssl source")
- }
- let mut shasum = if target.contains("apple") || build.build.contains("netbsd") {
- let mut cmd = Command::new("shasum");
- cmd.arg("-a").arg("256");
- cmd
- } else {
- Command::new("sha256sum")
- };
- let output = output(&mut shasum.arg(&tmp));
- let found = output.split_whitespace().next().unwrap();
- if found != OPENSSL_SHA256 {
- panic!("downloaded openssl sha256 different\n\
- expected: {}\n\
- found: {}\n", OPENSSL_SHA256, found);
+ if let Some(error) = last_error {
+ panic!("failed to download openssl source: {}", error);
}
t!(fs::rename(&tmp, &tarball));
}
diff --git a/src/liballoc/lib.rs b/src/liballoc/lib.rs
index d51aaa23c6a53..0cbfc9e9dacbb 100644
--- a/src/liballoc/lib.rs
+++ b/src/liballoc/lib.rs
@@ -121,6 +121,7 @@
#![feature(unique)]
#![feature(unsize)]
#![feature(allocator_internals)]
+#![feature(on_unimplemented)]
#![cfg_attr(not(test), feature(fused, fn_traits, placement_new_protocol, swap_with_slice, i128))]
#![cfg_attr(test, feature(test, box_heap))]
diff --git a/src/liballoc/vec.rs b/src/liballoc/vec.rs
index 861291194f369..cf34e195dea76 100644
--- a/src/liballoc/vec.rs
+++ b/src/liballoc/vec.rs
@@ -1543,6 +1543,7 @@ impl<T: Hash> Hash for Vec<T> {
}
#[stable(feature = "rust1", since = "1.0.0")]
+#[rustc_on_unimplemented = "vector indices are of type `usize` or ranges of `usize`"]
impl<T> Index<usize> for Vec<T> {
type Output = T;
@@ -1554,6 +1555,7 @@ impl<T> Index<usize> for Vec<T> {
}
#[stable(feature = "rust1", since = "1.0.0")]
+#[rustc_on_unimplemented = "vector indices are of type `usize` or ranges of `usize`"]
impl<T> IndexMut<usize> for Vec<T> {
#[inline]
fn index_mut(&mut self, index: usize) -> &mut T {
@@ -1562,8 +1564,8 @@ impl<T> IndexMut<usize> for Vec<T> {
}
}
-
#[stable(feature = "rust1", since = "1.0.0")]
+#[rustc_on_unimplemented = "vector indices are of type `usize` or ranges of `usize`"]
impl<T> ops::Index<ops::Range<usize>> for Vec<T> {
type Output = [T];
@@ -1572,7 +1574,9 @@ impl<T> ops::Index<ops::Range<usize>> for Vec<T> {
Index::index(&**self, index)
}
}
+
#[stable(feature = "rust1", since = "1.0.0")]
+#[rustc_on_unimplemented = "vector indices are of type `usize` or ranges of `usize`"]
impl<T> ops::Index<ops::RangeTo<usize>> for Vec<T> {
type Output = [T];
@@ -1581,7 +1585,9 @@ impl<T> ops::Index<ops::RangeTo<usize>> for Vec<T> {
Index::index(&**self, index)
}
}
+
#[stable(feature = "rust1", since = "1.0.0")]
+#[rustc_on_unimplemented = "vector indices are of type `usize` or ranges of `usize`"]
impl<T> ops::Index<ops::RangeFrom<usize>> for Vec<T> {
type Output = [T];
@@ -1590,7 +1596,9 @@ impl<T> ops::Index<ops::RangeFrom<usize>> for Vec<T> {
Index::index(&**self, index)
}
}
+
#[stable(feature = "rust1", since = "1.0.0")]
+#[rustc_on_unimplemented = "vector indices are of type `usize` or ranges of `usize`"]
impl<T> ops::Index<ops::RangeFull> for Vec<T> {
type Output = [T];
@@ -1599,7 +1607,9 @@ impl<T> ops::Index<ops::RangeFull> for Vec<T> {
self
}
}
+
#[unstable(feature = "inclusive_range", reason = "recently added, follows RFC", issue = "28237")]
+#[rustc_on_unimplemented = "vector indices are of type `usize` or ranges of `usize`"]
impl<T> ops::Index<ops::RangeInclusive<usize>> for Vec<T> {
type Output = [T];
@@ -1608,7 +1618,9 @@ impl<T> ops::Index<ops::RangeInclusive<usize>> for Vec<T> {
Index::index(&**self, index)
}
}
+
#[unstable(feature = "inclusive_range", reason = "recently added, follows RFC", issue = "28237")]
+#[rustc_on_unimplemented = "vector indices are of type `usize` or ranges of `usize`"]
impl<T> ops::Index<ops::RangeToInclusive<usize>> for Vec<T> {
type Output = [T];
@@ -1619,41 +1631,52 @@ impl<T> ops::Index<ops::RangeToInclusive<usize>> for Vec<T> {
}
#[stable(feature = "rust1", since = "1.0.0")]
+#[rustc_on_unimplemented = "vector indices are of type `usize` or ranges of `usize`"]
impl<T> ops::IndexMut<ops::Range<usize>> for Vec<T> {
#[inline]
fn index_mut(&mut self, index: ops::Range<usize>) -> &mut [T] {
IndexMut::index_mut(&mut **self, index)
}
}
+
#[stable(feature = "rust1", since = "1.0.0")]
+#[rustc_on_unimplemented = "vector indices are of type `usize` or ranges of `usize`"]
impl<T> ops::IndexMut<ops::RangeTo<usize>> for Vec<T> {
#[inline]
fn index_mut(&mut self, index: ops::RangeTo<usize>) -> &mut [T] {
IndexMut::index_mut(&mut **self, index)
}
}
+
#[stable(feature = "rust1", since = "1.0.0")]
+#[rustc_on_unimplemented = "vector indices are of type `usize` or ranges of `usize`"]
impl<T> ops::IndexMut<ops::RangeFrom<usize>> for Vec<T> {
#[inline]
fn index_mut(&mut self, index: ops::RangeFrom<usize>) -> &mut [T] {
IndexMut::index_mut(&mut **self, index)
}
}
+
#[stable(feature = "rust1", since = "1.0.0")]
+#[rustc_on_unimplemented = "vector indices are of type `usize` or ranges of `usize`"]
impl<T> ops::IndexMut<ops::RangeFull> for Vec<T> {
#[inline]
fn index_mut(&mut self, _index: ops::RangeFull) -> &mut [T] {
self
}
}
+
#[unstable(feature = "inclusive_range", reason = "recently added, follows RFC", issue = "28237")]
+#[rustc_on_unimplemented = "vector indices are of type `usize` or ranges of `usize`"]
impl<T> ops::IndexMut<ops::RangeInclusive<usize>> for Vec<T> {
#[inline]
fn index_mut(&mut self, index: ops::RangeInclusive<usize>) -> &mut [T] {
IndexMut::index_mut(&mut **self, index)
}
}
+
#[unstable(feature = "inclusive_range", reason = "recently added, follows RFC", issue = "28237")]
+#[rustc_on_unimplemented = "vector indices are of type `usize` or ranges of `usize`"]
impl<T> ops::IndexMut<ops::RangeToInclusive<usize>> for Vec<T> {
#[inline]
fn index_mut(&mut self, index: ops::RangeToInclusive<usize>) -> &mut [T] {
diff --git a/src/libcore/mem.rs b/src/libcore/mem.rs
index 680a0f5b2c03f..16d5fadc53620 100644
--- a/src/libcore/mem.rs
+++ b/src/libcore/mem.rs
@@ -429,9 +429,11 @@ pub fn align_of_val<T: ?Sized>(val: &T) -> usize {
/// Returns whether dropping values of type `T` matters.
///
-/// This is purely an optimization hint, and may be implemented conservatively.
-/// For instance, always returning `true` would be a valid implementation of
-/// this function.
+/// This is purely an optimization hint, and may be implemented conservatively:
+/// it may return `true` for types that don't actually need to be dropped.
+/// As such always returning `true` would be a valid implementation of
+/// this function. However if this function actually returns `false`, then you
+/// can be certain dropping `T` has no side effect.
///
/// Low level implementations of things like collections, which need to manually
/// drop their data, should use this function to avoid unnecessarily
diff --git a/src/librustc/middle/reachable.rs b/src/librustc/middle/reachable.rs
index 55d0c6b4c66a3..bb6213cb5faaf 100644
--- a/src/librustc/middle/reachable.rs
+++ b/src/librustc/middle/reachable.rs
@@ -336,6 +336,12 @@ struct CollectPrivateImplItemsVisitor<'a, 'tcx: 'a> {
impl<'a, 'tcx: 'a> ItemLikeVisitor<'tcx> for CollectPrivateImplItemsVisitor<'a, 'tcx> {
fn visit_item(&mut self, item: &hir::Item) {
+ // Anything which has custom linkage gets thrown on the worklist no
+ // matter where it is in the crate.
+ if attr::contains_name(&item.attrs, "linkage") {
+ self.worklist.push(item.id);
+ }
+
// We need only trait impls here, not inherent impls, and only non-exported ones
if let hir::ItemImpl(.., Some(ref trait_ref), _, ref impl_item_refs) = item.node {
if !self.access_levels.is_reachable(item.id) {
diff --git a/src/librustc/mir/mod.rs b/src/librustc/mir/mod.rs
index 075a629de04da..0159a198bc647 100644
--- a/src/librustc/mir/mod.rs
+++ b/src/librustc/mir/mod.rs
@@ -415,9 +415,11 @@ pub enum BorrowKind {
///////////////////////////////////////////////////////////////////////////
// Variables and temps
-newtype_index!(Local, "_");
-
-pub const RETURN_POINTER: Local = Local(0);
+newtype_index!(Local
+ {
+ DEBUG_NAME = "_",
+ const RETURN_POINTER = 0,
+ });
/// Classifies locals into categories. See `Mir::local_kind`.
#[derive(PartialEq, Eq, Debug)]
@@ -551,7 +553,7 @@ pub struct UpvarDecl {
///////////////////////////////////////////////////////////////////////////
// BasicBlock
-newtype_index!(BasicBlock, "bb");
+newtype_index!(BasicBlock { DEBUG_NAME = "bb" });
///////////////////////////////////////////////////////////////////////////
// BasicBlockData and Terminator
@@ -1131,7 +1133,7 @@ pub type LvalueProjection<'tcx> = Projection<'tcx, Lvalue<'tcx>, Local, Ty<'tcx>
/// and the index is a local.
pub type LvalueElem<'tcx> = ProjectionElem<'tcx, Local, Ty<'tcx>>;
-newtype_index!(Field, "field");
+newtype_index!(Field { DEBUG_NAME = "field" });
impl<'tcx> Lvalue<'tcx> {
pub fn field(self, f: Field, ty: Ty<'tcx>) -> Lvalue<'tcx> {
@@ -1196,8 +1198,11 @@ impl<'tcx> Debug for Lvalue<'tcx> {
///////////////////////////////////////////////////////////////////////////
// Scopes
-newtype_index!(VisibilityScope, "scope");
-pub const ARGUMENT_VISIBILITY_SCOPE : VisibilityScope = VisibilityScope(0);
+newtype_index!(VisibilityScope
+ {
+ DEBUG_NAME = "scope",
+ const ARGUMENT_VISIBILITY_SCOPE = 0,
+ });
#[derive(Clone, Debug, RustcEncodable, RustcDecodable)]
pub struct VisibilityScopeData {
@@ -1522,7 +1527,7 @@ pub struct Constant<'tcx> {
pub literal: Literal<'tcx>,
}
-newtype_index!(Promoted, "promoted");
+newtype_index!(Promoted { DEBUG_NAME = "promoted" });
#[derive(Clone, PartialEq, Eq, Hash, RustcEncodable, RustcDecodable)]
pub enum Literal<'tcx> {
diff --git a/src/librustc_borrowck/borrowck/mod.rs b/src/librustc_borrowck/borrowck/mod.rs
index a3f1340d42911..d6f7c2aa887f0 100644
--- a/src/librustc_borrowck/borrowck/mod.rs
+++ b/src/librustc_borrowck/borrowck/mod.rs
@@ -759,7 +759,21 @@ impl<'a, 'tcx> BorrowckCtxt<'a, 'tcx> {
let mut db = match err.cause {
MutabilityViolation => {
- self.cannot_assign(error_span, &descr, Origin::Ast)
+ let mut db = self.cannot_assign(error_span, &descr, Origin::Ast);
+ if let mc::NoteClosureEnv(upvar_id) = err.cmt.note {
+ let node_id = self.tcx.hir.hir_to_node_id(upvar_id.var_id);
+ let sp = self.tcx.hir.span(node_id);
+ match self.tcx.sess.codemap().span_to_snippet(sp) {
+ Ok(snippet) => {
+ let msg = &format!("consider making `{}` mutable", snippet);
+ db.span_suggestion(sp, msg, format!("mut {}", snippet));
+ }
+ _ => {
+ db.span_help(sp, "consider making this binding mutable");
+ }
+ }
+ }
+ db
}
BorrowViolation(euv::ClosureCapture(_)) => {
struct_span_err!(self.tcx.sess, error_span, E0595,
diff --git a/src/librustc_data_structures/indexed_vec.rs b/src/librustc_data_structures/indexed_vec.rs
index 4b7f55eba06be..6c5a37aa1e575 100644
--- a/src/librustc_data_structures/indexed_vec.rs
+++ b/src/librustc_data_structures/indexed_vec.rs
@@ -40,39 +40,80 @@ impl Idx for u32 {
#[macro_export]
macro_rules! newtype_index {
+ // ---- public rules ----
+
+ // Use default constants
($name:ident) => (
- newtype_index!($name, unsafe { ::std::intrinsics::type_name::<$name>() });
+ newtype_index!(
+ @type[$name]
+ @max[::std::u32::MAX]
+ @debug_name[unsafe {::std::intrinsics::type_name::<$name>() }]);
+ );
+
+ // Define any constants
+ ($name:ident { $($tokens:tt)+ }) => (
+ newtype_index!(
+ @type[$name]
+ @max[::std::u32::MAX]
+ @debug_name[unsafe {::std::intrinsics::type_name::<$name>() }]
+ $($tokens)+);
);
- ($name:ident, $debug_name:expr) => (
+ // ---- private rules ----
+
+ // Base case, user-defined constants (if any) have already been defined
+ (@type[$type:ident] @max[$max:expr] @debug_name[$debug_name:expr]) => (
#[derive(Copy, Clone, PartialEq, Eq, Hash, PartialOrd, Ord,
- RustcEncodable, RustcDecodable)]
- pub struct $name(u32);
-
- impl $name {
- // HACK use for constants
- #[allow(unused)]
- const fn const_new(x: u32) -> Self {
- $name(x)
- }
- }
+ RustcEncodable, RustcDecodable)]
+ pub struct $type(u32);
- impl Idx for $name {
+ impl Idx for $type {
fn new(value: usize) -> Self {
- assert!(value < (::std::u32::MAX) as usize);
- $name(value as u32)
+ assert!(value < ($max) as usize);
+ $type(value as u32)
}
fn index(self) -> usize {
self.0 as usize
}
}
- impl ::std::fmt::Debug for $name {
+ impl ::std::fmt::Debug for $type {
fn fmt(&self, fmt: &mut ::std::fmt::Formatter) -> ::std::fmt::Result {
write!(fmt, "{}{}", $debug_name, self.0)
}
}
- )
+ );
+
+ // Rewrite final without comma to one that includes comma
+ (@type[$type:ident] @max[$max:expr] @debug_name[$debug_name:expr]
+ $name:ident = $constant:expr) => (
+ newtype_index!(@type[$type] @max[$max] @debug_name[$debug_name] $name = $constant,);
+ );
+
+ // Rewrite final const without comma to one that includes comma
+ (@type[$type:ident] @max[$_max:expr] @debug_name[$debug_name:expr]
+ const $name:ident = $constant:expr) => (
+ newtype_index!(@type[$type] @max[$max] @debug_name[$debug_name] const $name = $constant,);
+ );
+
+ // Replace existing default for max
+ (@type[$type:ident] @max[$_max:expr] @debug_name[$debug_name:expr]
+ MAX = $max:expr, $($tokens:tt)*) => (
+ newtype_index!(@type[$type] @max[$max] @debug_name[$debug_name] $(tokens)*);
+ );
+
+ // Replace existing default for debug_name
+ (@type[$type:ident] @max[$max:expr] @debug_name[$_debug_name:expr]
+ DEBUG_NAME = $debug_name:expr, $($tokens:tt)*) => (
+ newtype_index!(@type[$type] @max[$max] @debug_name[$debug_name] $($tokens)*);
+ );
+
+ // Assign a user-defined constant (as final param)
+ (@type[$type:ident] @max[$max:expr] @debug_name[$debug_name:expr]
+ const $name:ident = $constant:expr, $($tokens:tt)*) => (
+ pub const $name: $type = $type($constant);
+ newtype_index!(@type[$type] @max[$max] @debug_name[$debug_name] $($tokens)*);
+ );
}
#[derive(Clone, PartialEq, Eq)]
diff --git a/src/librustc_resolve/lib.rs b/src/librustc_resolve/lib.rs
index 36cd69f91b9c3..4aab43cbec701 100644
--- a/src/librustc_resolve/lib.rs
+++ b/src/librustc_resolve/lib.rs
@@ -137,7 +137,7 @@ enum ResolutionError<'a> {
/// error E0416: identifier is bound more than once in the same pattern
IdentifierBoundMoreThanOnceInSamePattern(&'a str),
/// error E0426: use of undeclared label
- UndeclaredLabel(&'a str),
+ UndeclaredLabel(&'a str, Option<Name>),
/// error E0429: `self` imports are only allowed within a { } list
SelfImportsOnlyAllowedWithin,
/// error E0430: `self` import can only appear once in the list
@@ -263,13 +263,17 @@ fn resolve_struct_error<'sess, 'a>(resolver: &'sess Resolver,
err.span_label(span, "used in a pattern more than once");
err
}
- ResolutionError::UndeclaredLabel(name) => {
+ ResolutionError::UndeclaredLabel(name, lev_candidate) => {
let mut err = struct_span_err!(resolver.session,
span,
E0426,
"use of undeclared label `{}`",
name);
- err.span_label(span, format!("undeclared label `{}`", name));
+ if let Some(lev_candidate) = lev_candidate {
+ err.span_label(span, format!("did you mean `{}`?", lev_candidate));
+ } else {
+ err.span_label(span, format!("undeclared label `{}`", name));
+ }
err
}
ResolutionError::SelfImportsOnlyAllowedWithin => {
@@ -1790,9 +1794,13 @@ impl<'a> Resolver<'a> {
}
}
- /// Searches the current set of local scopes for labels.
+ /// Searches the current set of local scopes for labels. Returns the first non-None label that
+ /// is returned by the given predicate function
+ ///
/// Stops after meeting a closure.
- fn search_label(&self, mut ident: Ident) -> Option<Def> {
+ fn search_label<P, R>(&self, mut ident: Ident, pred: P) -> Option<R>
+ where P: Fn(&Rib, Ident) -> Option<R>
+ {
for rib in self.label_ribs.iter().rev() {
match rib.kind {
NormalRibKind => {}
@@ -1808,9 +1816,9 @@ impl<'a> Resolver<'a> {
return None;
}
}
- let result = rib.bindings.get(&ident).cloned();
- if result.is_some() {
- return result;
+ let r = pred(rib, ident);
+ if r.is_some() {
+ return r;
}
}
None
@@ -3202,12 +3210,20 @@ impl<'a> Resolver<'a> {
}
ExprKind::Break(Some(label), _) | ExprKind::Continue(Some(label)) => {
- match self.search_label(label.node) {
+ match self.search_label(label.node, |rib, id| rib.bindings.get(&id).cloned()) {
None => {
+ // Search again for close matches...
+ // Picks the first label that is "close enough", which is not necessarily
+ // the closest match
+ let close_match = self.search_label(label.node, |rib, ident| {
+ let names = rib.bindings.iter().map(|(id, _)| &id.name);
+ find_best_match_for_name(names, &*ident.name.as_str(), None)
+ });
self.record_def(expr.id, err_path_resolution());
resolve_error(self,
label.span,
- ResolutionError::UndeclaredLabel(&label.node.name.as_str()));
+ ResolutionError::UndeclaredLabel(&label.node.name.as_str(),
+ close_match));
}
Some(def @ Def::Label(_)) => {
// Since this def is a label, it is never read.
diff --git a/src/librustdoc/html/static/rustdoc.css b/src/librustdoc/html/static/rustdoc.css
index f0d6f46184a65..9e2798f1cf71a 100644
--- a/src/librustdoc/html/static/rustdoc.css
+++ b/src/librustdoc/html/static/rustdoc.css
@@ -394,7 +394,7 @@ h4 > code, h3 > code, .invisible > code {
padding: 0;
}
-.content .item-list li { margin-bottom: 3px; }
+.content .item-list li { margin-bottom: 1em; }
.content .multi-column {
-moz-column-count: 5;
@@ -773,17 +773,19 @@ span.since {
}
.sidebar {
- height: 40px;
+ height: 45px;
min-height: 40px;
- width: 100%;
- margin: 0px;
- padding: 0px;
+ width: calc(100% + 30px);
+ margin: 0;
+ margin-left: -15px;
+ padding: 0 15px;
position: static;
}
.sidebar .location {
float: right;
margin: 0px;
+ margin-top: 2px;
padding: 3px 10px 1px 10px;
min-height: 39px;
background: inherit;
@@ -798,7 +800,7 @@ span.since {
.sidebar img {
width: 35px;
margin-top: 5px;
- margin-bottom: 0px;
+ margin-bottom: 5px;
float: left;
}
diff --git a/src/libstd/ffi/c_str.rs b/src/libstd/ffi/c_str.rs
index f9d803364772f..b54603919427c 100644
--- a/src/libstd/ffi/c_str.rs
+++ b/src/libstd/ffi/c_str.rs
@@ -23,19 +23,69 @@ use ptr;
use slice;
use str::{self, Utf8Error};
-/// A type representing an owned C-compatible string.
+/// A type representing an owned, C-compatible, nul-terminated string with no nul bytes in the
+/// middle.
///
-/// This type serves the primary purpose of being able to safely generate a
+/// This type serves the purpose of being able to safely generate a
/// C-compatible string from a Rust byte slice or vector. An instance of this
/// type is a static guarantee that the underlying bytes contain no interior 0
-/// bytes and the final byte is 0.
+/// bytes ("nul characters") and that the final byte is 0 ("nul terminator").
///
-/// A `CString` is created from either a byte slice or a byte vector. A [`u8`]
-/// slice can be obtained with the `as_bytes` method. Slices produced from a
-/// `CString` do *not* contain the trailing nul terminator unless otherwise
-/// specified.
+/// `CString` is to [`CStr`] as [`String`] is to [`&str`]: the former
+/// in each pair are owned strings; the latter are borrowed
+/// references.
///
+/// # Creating a `CString`
+///
+/// A `CString` is created from either a byte slice or a byte vector,
+/// or anything that implements [`Into`]`<`[`Vec`]`<`[`u8`]`>>` (for
+/// example, you can build a `CString` straight out of a [`String`] or
+/// a [`&str`], since both implement that trait).
+///
+/// The [`new`] method will actually check that the provided `&[u8]`
+/// does not have 0 bytes in the middle, and return an error if it
+/// finds one.
+///
+/// # Extracting a raw pointer to the whole C string
+///
+/// `CString` implements a [`as_ptr`] method through the [`Deref`]
+/// trait. This method will give you a `*const c_char` which you can
+/// feed directly to extern functions that expect a nul-terminated
+/// string, like C's `strdup()`.
+///
+/// # Extracting a slice of the whole C string
+///
+/// Alternatively, you can obtain a `&[`[`u8`]`]` slice from a
+/// `CString` with the [`as_bytes`] method. Slices produced in this
+/// way do *not* contain the trailing nul terminator. This is useful
+/// when you will be calling an extern function that takes a `*const
+/// u8` argument which is not necessarily nul-terminated, plus another
+/// argument with the length of the string — like C's `strndup()`.
+/// You can of course get the slice's length with its
+/// [`len`][slice.len] method.
+///
+/// If you need a `&[`[`u8`]`]` slice *with* the nul terminator, you
+/// can use [`as_bytes_with_nul`] instead.
+///
+/// Once you have the kind of slice you need (with or without a nul
+/// terminator), you can call the slice's own
+/// [`as_ptr`][slice.as_ptr] method to get a raw pointer to pass to
+/// extern functions. See the documentation for that function for a
+/// discussion on ensuring the lifetime of the raw pointer.
+///
+/// [`Into`]: ../convert/trait.Into.html
+/// [`Vec`]: ../vec/struct.Vec.html
+/// [`String`]: ../string/struct.String.html
+/// [`&str`]: ../primitive.str.html
/// [`u8`]: ../primitive.u8.html
+/// [`new`]: #method.new
+/// [`as_bytes`]: #method.as_bytes
+/// [`as_bytes_with_nul`]: #method.as_bytes_with_nul
+/// [`as_ptr`]: #method.as_ptr
+/// [slice.as_ptr]: ../primitive.slice.html#method.as_ptr
+/// [slice.len]: ../primitive.slice.html#method.len
+/// [`Deref`]: ../ops/trait.Deref.html
+/// [`CStr`]: struct.CStr.html
///
/// # Examples
///
@@ -48,6 +98,8 @@ use str::{self, Utf8Error};
/// fn my_printer(s: *const c_char);
/// }
///
+/// // We are certain that our string doesn't have 0 bytes in the middle,
+/// // so we can .unwrap()
/// let c_to_print = CString::new("Hello, world!").unwrap();
/// unsafe {
/// my_printer(c_to_print.as_ptr());
@@ -58,7 +110,7 @@ use str::{self, Utf8Error};
/// # Safety
///
/// `CString` is intended for working with traditional C-style strings
-/// (a sequence of non-null bytes terminated by a single null byte); the
+/// (a sequence of non-nul bytes terminated by a single nul byte); the
/// primary use case for these kinds of strings is interoperating with C-like
/// code. Often you will need to transfer ownership to/from that external
/// code. It is strongly recommended that you thoroughly read through the
@@ -77,17 +129,21 @@ pub struct CString {
/// Representation of a borrowed C string.
///
-/// This dynamically sized type is only safely constructed via a borrowed
-/// version of an instance of `CString`. This type can be constructed from a raw
-/// C string as well and represents a C string borrowed from another location.
+/// This type represents a borrowed reference to a nul-terminated
+/// array of bytes. It can be constructed safely from a `&[`[`u8`]`]`
+/// slice, or unsafely from a raw `*const c_char`. It can then be
+/// converted to a Rust [`&str`] by performing UTF-8 validation, or
+/// into an owned [`CString`].
+///
+/// `CStr` is to [`CString`] as [`&str`] is to [`String`]: the former
+/// in each pair are borrowed references; the latter are owned
+/// strings.
///
/// Note that this structure is **not** `repr(C)` and is not recommended to be
-/// placed in the signatures of FFI functions. Instead safe wrappers of FFI
+/// placed in the signatures of FFI functions. Instead, safe wrappers of FFI
/// functions may leverage the unsafe [`from_ptr`] constructor to provide a safe
/// interface to other consumers.
///
-/// [`from_ptr`]: #method.from_ptr
-///
/// # Examples
///
/// Inspecting a foreign C string:
@@ -100,7 +156,7 @@ pub struct CString {
///
/// unsafe {
/// let slice = CStr::from_ptr(my_string());
-/// println!("string length: {}", slice.to_bytes().len());
+/// println!("string buffer size without nul terminator: {}", slice.to_bytes().len());
/// }
/// ```
///
@@ -122,8 +178,6 @@ pub struct CString {
///
/// Converting a foreign C string into a Rust [`String`]:
///
-/// [`String`]: ../string/struct.String.html
-///
/// ```no_run
/// use std::ffi::CStr;
/// use std::os::raw::c_char;
@@ -138,6 +192,12 @@ pub struct CString {
///
/// println!("string: {}", my_string_safe());
/// ```
+///
+/// [`u8`]: ../primitive.u8.html
+/// [`&str`]: ../primitive.str.html
+/// [`String`]: ../string/struct.String.html
+/// [`CString`]: struct.CString.html
+/// [`from_ptr`]: #method.from_ptr
#[derive(Hash)]
#[stable(feature = "rust1", since = "1.0.0")]
pub struct CStr {
@@ -148,9 +208,15 @@ pub struct CStr {
inner: [c_char]
}
-/// An error returned from [`CString::new`] to indicate that a nul byte was found
-/// in the vector provided.
+/// An error indicating that an interior nul byte was found.
+///
+/// While Rust strings may contain nul bytes in the middle, C strings
+/// can't, as that byte would effectively truncate the string.
///
+/// This error is created by the [`new`][`CString::new`] method on
+/// [`CString`]. See its documentation for more.
+///
+/// [`CString`]: struct.CString.html
/// [`CString::new`]: struct.CString.html#method.new
///
/// # Examples
@@ -164,9 +230,16 @@ pub struct CStr {
#[stable(feature = "rust1", since = "1.0.0")]
pub struct NulError(usize, Vec<u8>);
-/// An error returned from [`CStr::from_bytes_with_nul`] to indicate that a nul
-/// byte was found too early in the slice provided or one wasn't found at all.
+/// An error indicating that a nul byte was not in the expected position.
+///
+/// The slice used to create a [`CStr`] must have one and only one nul
+/// byte at the end of the slice.
///
+/// This error is created by the
+/// [`from_bytes_with_nul`][`CStr::from_bytes_with_nul`] method on
+/// [`CStr`]. See its documentation for more.
+///
+/// [`CStr`]: struct.CStr.html
/// [`CStr::from_bytes_with_nul`]: struct.CStr.html#method.from_bytes_with_nul
///
/// # Examples
@@ -201,9 +274,18 @@ impl FromBytesWithNulError {
}
}
-/// An error returned from [`CString::into_string`] to indicate that a UTF-8 error
-/// was encountered during the conversion.
+/// An error indicating invalid UTF-8 when converting a [`CString`] into a [`String`].
+///
+/// `CString` is just a wrapper over a buffer of bytes with a nul
+/// terminator; [`into_string`][`CString::into_string`] performs UTF-8
+/// validation on those bytes and may return this error.
+///
+/// This `struct` is created by the
+/// [`into_string`][`CString::into_string`] method on [`CString`]. See
+/// its documentation for more.
///
+/// [`String`]: ../string/struct.String.html
+/// [`CString`]: struct.CString.html
/// [`CString::into_string`]: struct.CString.html#method.into_string
#[derive(Clone, PartialEq, Eq, Debug)]
#[stable(feature = "cstring_into", since = "1.7.0")]
@@ -215,8 +297,11 @@ pub struct IntoStringError {
impl CString {
/// Creates a new C-compatible string from a container of bytes.
///
- /// This method will consume the provided data and use the underlying bytes
- /// to construct a new string, ensuring that there is a trailing 0 byte.
+ /// This function will consume the provided data and use the
+ /// underlying bytes to construct a new string, ensuring that
+ /// there is a trailing 0 byte. This trailing 0 byte will be
+ /// appended by this function; the provided data should *not*
+ /// contain any 0 bytes in it.
///
/// # Examples
///
@@ -234,9 +319,11 @@ impl CString {
///
/// # Errors
///
- /// This function will return an error if the bytes yielded contain an
- /// internal 0 byte. The error returned will contain the bytes as well as
+ /// This function will return an error if the supplied bytes contain an
+ /// internal 0 byte. The [`NulError`] returned will contain the bytes as well as
/// the position of the nul byte.
+ ///
+ /// [`NulError`]: struct.NulError.html
#[stable(feature = "rust1", since = "1.0.0")]
pub fn new<T: Into<Vec<u8>>>(t: T) -> Result<CString, NulError> {
Self::_new(t.into())
@@ -249,8 +336,8 @@ impl CString {
}
}
- /// Creates a C-compatible string from a byte vector without checking for
- /// interior 0 bytes.
+ /// Creates a C-compatible string by consuming a byte vector,
+ /// without checking for interior 0 bytes.
///
/// This method is equivalent to [`new`] except that no runtime assertion
/// is made that `v` contains no 0 bytes, and it requires an actual
@@ -275,7 +362,7 @@ impl CString {
CString { inner: v.into_boxed_slice() }
}
- /// Retakes ownership of a `CString` that was transferred to C.
+ /// Retakes ownership of a `CString` that was transferred to C via [`into_raw`].
///
/// Additionally, the length of the string will be recalculated from the pointer.
///
@@ -286,7 +373,14 @@ impl CString {
/// ownership of a string that was allocated by foreign code) is likely to lead
/// to undefined behavior or allocator corruption.
///
+ /// > **Note:** If you need to borrow a string that was allocated by
+ /// > foreign code, use [`CStr`]. If you need to take ownership of
+ /// > a string that was allocated by foreign code, you will need to
+ /// > make your own provisions for freeing it appropriately, likely
+ /// > with the foreign code's API to do that.
+ ///
/// [`into_raw`]: #method.into_raw
+ /// [`CStr`]: struct.CStr.html
///
/// # Examples
///
@@ -315,11 +409,11 @@ impl CString {
CString { inner: Box::from_raw(slice as *mut [c_char] as *mut [u8]) }
}
- /// Transfers ownership of the string to a C caller.
+ /// Consumes the `CString` and transfers ownership of the string to a C caller.
///
- /// The pointer must be returned to Rust and reconstituted using
+ /// The pointer which this function returns must be returned to Rust and reconstituted using
/// [`from_raw`] to be properly deallocated. Specifically, one
- /// should *not* use the standard C `free` function to deallocate
+ /// should *not* use the standard C `free()` function to deallocate
/// this string.
///
/// Failure to call [`from_raw`] will lead to a memory leak.
@@ -351,11 +445,27 @@ impl CString {
Box::into_raw(self.into_inner()) as *mut c_char
}
- /// Converts the `CString` into a [`String`] if it contains valid Unicode data.
+ /// Converts the `CString` into a [`String`] if it contains valid UTF-8 data.
///
/// On failure, ownership of the original `CString` is returned.
///
/// [`String`]: ../string/struct.String.html
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use std::ffi::CString;
+ ///
+ /// let valid_utf8 = vec![b'f', b'o', b'o'];
+ /// let cstring = CString::new(valid_utf8).unwrap();
+ /// assert_eq!(cstring.into_string().unwrap(), "foo");
+ ///
+ /// let invalid_utf8 = vec![b'f', 0xff, b'o', b'o'];
+ /// let cstring = CString::new(invalid_utf8).unwrap();
+ /// let err = cstring.into_string().err().unwrap();
+ /// assert_eq!(err.utf8_error().valid_up_to(), 1);
+ /// ```
+
#[stable(feature = "cstring_into", since = "1.7.0")]
pub fn into_string(self) -> Result<String, IntoStringError> {
String::from_utf8(self.into_bytes())
@@ -365,10 +475,11 @@ impl CString {
})
}
- /// Returns the underlying byte buffer.
+ /// Consumes the `CString` and returns the underlying byte buffer.
///
- /// The returned buffer does **not** contain the trailing nul separator and
- /// it is guaranteed to not have any interior nul bytes.
+ /// The returned buffer does **not** contain the trailing nul
+ /// terminator, and it is guaranteed to not have any interior nul
+ /// bytes.
///
/// # Examples
///
@@ -388,7 +499,7 @@ impl CString {
}
/// Equivalent to the [`into_bytes`] function except that the returned vector
- /// includes the trailing nul byte.
+ /// includes the trailing nul terminator.
///
/// [`into_bytes`]: #method.into_bytes
///
@@ -408,8 +519,12 @@ impl CString {
/// Returns the contents of this `CString` as a slice of bytes.
///
- /// The returned slice does **not** contain the trailing nul separator and
- /// it is guaranteed to not have any interior nul bytes.
+ /// The returned slice does **not** contain the trailing nul
+ /// terminator, and it is guaranteed to not have any interior nul
+ /// bytes. If you need the nul terminator, use
+ /// [`as_bytes_with_nul`] instead.
+ ///
+ /// [`as_bytes_with_nul`]: #method.as_bytes_with_nul
///
/// # Examples
///
@@ -427,7 +542,7 @@ impl CString {
}
/// Equivalent to the [`as_bytes`] function except that the returned slice
- /// includes the trailing nul byte.
+ /// includes the trailing nul terminator.
///
/// [`as_bytes`]: #method.as_bytes
///
@@ -598,8 +713,8 @@ impl Default for Box<CStr> {
}
impl NulError {
- /// Returns the position of the nul byte in the slice that was provided to
- /// [`CString::new`].
+ /// Returns the position of the nul byte in the slice that caused
+ /// [`CString::new`] to fail.
///
/// [`CString::new`]: struct.CString.html#method.new
///
@@ -711,9 +826,9 @@ impl fmt::Display for IntoStringError {
}
impl CStr {
- /// Casts a raw C string to a safe C string wrapper.
+ /// Wraps a raw C string with a safe C string wrapper.
///
- /// This function will cast the provided `ptr` to the `CStr` wrapper which
+ /// This function will wrap the provided `ptr` with a `CStr` wrapper, which
/// allows inspection and interoperation of non-owned C strings. This method
/// is unsafe for a number of reasons:
///
@@ -753,9 +868,9 @@ impl CStr {
/// Creates a C string wrapper from a byte slice.
///
- /// This function will cast the provided `bytes` to a `CStr` wrapper after
- /// ensuring that it is null terminated and does not contain any interior
- /// nul bytes.
+ /// This function will cast the provided `bytes` to a `CStr`
+ /// wrapper after ensuring that the byte slice is nul-terminated
+ /// and does not contain any interior nul bytes.
///
/// # Examples
///
@@ -766,7 +881,7 @@ impl CStr {
/// assert!(cstr.is_ok());
/// ```
///
- /// Creating a `CStr` without a trailing nul byte is an error:
+ /// Creating a `CStr` without a trailing nul terminator is an error:
///
/// ```
/// use std::ffi::CStr;
@@ -800,7 +915,7 @@ impl CStr {
/// Unsafely creates a C string wrapper from a byte slice.
///
/// This function will cast the provided `bytes` to a `CStr` wrapper without
- /// performing any sanity checks. The provided slice must be null terminated
+ /// performing any sanity checks. The provided slice **must** be nul-terminated
/// and not contain any interior nul bytes.
///
/// # Examples
@@ -822,7 +937,7 @@ impl CStr {
/// Returns the inner pointer to this C string.
///
- /// The returned pointer will be valid for as long as `self` is and points
+ /// The returned pointer will be valid for as long as `self` is, and points
/// to a contiguous region of memory terminated with a 0 byte to represent
/// the end of the string.
///
@@ -843,9 +958,9 @@ impl CStr {
/// ```
///
/// This happens because the pointer returned by `as_ptr` does not carry any
- /// lifetime information and the string is deallocated immediately after
+ /// lifetime information and the [`CString`] is deallocated immediately after
/// the `CString::new("Hello").unwrap().as_ptr()` expression is evaluated.
- /// To fix the problem, bind the string to a local variable:
+ /// To fix the problem, bind the `CString` to a local variable:
///
/// ```no_run
/// use std::ffi::{CString};
@@ -857,6 +972,11 @@ impl CStr {
/// *ptr;
/// }
/// ```
+ ///
+ /// This way, the lifetime of the `CString` in `hello` encompasses
+ /// the lifetime of `ptr` and the `unsafe` block.
+ ///
+ /// [`CString`]: struct.CString.html
#[inline]
#[stable(feature = "rust1", since = "1.0.0")]
pub fn as_ptr(&self) -> *const c_char {
@@ -865,11 +985,7 @@ impl CStr {
/// Converts this C string to a byte slice.
///
- /// This function will calculate the length of this string (which normally
- /// requires a linear amount of work to be done) and then return the
- /// resulting slice of `u8` elements.
- ///
- /// The returned slice will **not** contain the trailing nul that this C
+ /// The returned slice will **not** contain the trailing nul terminator that this C
/// string has.
///
/// > **Note**: This method is currently implemented as a 0-cost cast, but
@@ -894,7 +1010,7 @@ impl CStr {
/// Converts this C string to a byte slice containing the trailing 0 byte.
///
/// This function is the equivalent of [`to_bytes`] except that it will retain
- /// the trailing nul instead of chopping it off.
+ /// the trailing nul terminator instead of chopping it off.
///
/// > **Note**: This method is currently implemented as a 0-cost cast, but
/// > it is planned to alter its definition in the future to perform the
@@ -918,8 +1034,9 @@ impl CStr {
/// Yields a [`&str`] slice if the `CStr` contains valid UTF-8.
///
- /// This function will calculate the length of this string and check for
- /// UTF-8 validity, and then return the [`&str`] if it's valid.
+ /// If the contents of the `CStr` are valid UTF-8 data, this
+ /// function will return the corresponding [`&str`] slice. Otherwise,
+ /// it will return an error with details of where UTF-8 validation failed.
///
/// > **Note**: This method is currently implemented to check for validity
/// > after a 0-cost cast, but it is planned to alter its definition in the
@@ -947,10 +1064,12 @@ impl CStr {
/// Converts a `CStr` into a [`Cow`]`<`[`str`]`>`.
///
- /// This function will calculate the length of this string (which normally
- /// requires a linear amount of work to be done) and then return the
- /// resulting slice as a [`Cow`]`<`[`str`]`>`, replacing any invalid UTF-8 sequences
- /// with `U+FFFD REPLACEMENT CHARACTER`.
+ /// If the contents of the `CStr` are valid UTF-8 data, this
+ /// function will return a [`Cow`]`::`[`Borrowed`]`(`[`&str`]`)`
+ /// with the the corresponding [`&str`] slice. Otherwise, it will
+ /// replace any invalid UTF-8 sequences with `U+FFFD REPLACEMENT
+ /// CHARACTER` and return a [`Cow`]`::`[`Owned`]`(`[`String`]`)`
+ /// with the result.
///
/// > **Note**: This method is currently implemented to check for validity
/// > after a 0-cost cast, but it is planned to alter its definition in the
@@ -958,7 +1077,9 @@ impl CStr {
/// > check whenever this method is called.
///
/// [`Cow`]: ../borrow/enum.Cow.html
+ /// [`Borrowed`]: ../borrow/enum.Cow.html#variant.Borrowed
/// [`str`]: ../primitive.str.html
+ /// [`String`]: ../string/struct.String.html
///
/// # Examples
///
diff --git a/src/libstd/ffi/mod.rs b/src/libstd/ffi/mod.rs
index ca1ff18f1cad8..a75596351e4cf 100644
--- a/src/libstd/ffi/mod.rs
+++ b/src/libstd/ffi/mod.rs
@@ -9,6 +9,157 @@
// except according to those terms.
//! Utilities related to FFI bindings.
+//!
+//! This module provides utilities to handle data across non-Rust
+//! interfaces, like other programming languages and the underlying
+//! operating system. It is mainly of use for FFI (Foreign Function
+//! Interface) bindings and code that needs to exchange C-like strings
+//! with other languages.
+//!
+//! # Overview
+//!
+//! Rust represents owned strings with the [`String`] type, and
+//! borrowed slices of strings with the [`str`] primitive. Both are
+//! always in UTF-8 encoding, and may contain nul bytes in the middle,
+//! i.e. if you look at the bytes that make up the string, there may
+//! be a `\0` among them. Both `String` and `str` store their length
+//! explicitly; there are no nul terminators at the end of strings
+//! like in C.
+//!
+//! C strings are different from Rust strings:
+//!
+//! * **Encodings** - Rust strings are UTF-8, but C strings may use
+//! other encodings. If you are using a string from C, you should
+//! check its encoding explicitly, rather than just assuming that it
+//! is UTF-8 like you can do in Rust.
+//!
+//! * **Character size** - C strings may use `char` or `wchar_t`-sized
+//! characters; please **note** that C's `char` is different from Rust's.
+//! The C standard leaves the actual sizes of those types open to
+//! interpretation, but defines different APIs for strings made up of
+//! each character type. Rust strings are always UTF-8, so different
+//! Unicode characters will be encoded in a variable number of bytes
+//! each. The Rust type [`char`] represents a '[Unicode scalar
+//! value]', which is similar to, but not the same as, a '[Unicode
+//! code point]'.
+//!
+//! * **Nul terminators and implicit string lengths** - Often, C
+//! strings are nul-terminated, i.e. they have a `\0` character at the
+//! end. The length of a string buffer is not stored, but has to be
+//! calculated; to compute the length of a string, C code must
+//! manually call a function like `strlen()` for `char`-based strings,
+//! or `wcslen()` for `wchar_t`-based ones. Those functions return
+//! the number of characters in the string excluding the nul
+//! terminator, so the buffer length is really `len+1` characters.
+//! Rust strings don't have a nul terminator; their length is always
+//! stored and does not need to be calculated. While in Rust
+//! accessing a string's length is a O(1) operation (becasue the
+//! length is stored); in C it is an O(length) operation because the
+//! length needs to be computed by scanning the string for the nul
+//! terminator.
+//!
+//! * **Internal nul characters** - When C strings have a nul
+//! terminator character, this usually means that they cannot have nul
+//! characters in the middle — a nul character would essentially
+//! truncate the string. Rust strings *can* have nul characters in
+//! the middle, because nul does not have to mark the end of the
+//! string in Rust.
+//!
+//! # Representations of non-Rust strings
+//!
+//! [`CString`] and [`CStr`] are useful when you need to transfer
+//! UTF-8 strings to and from languages with a C ABI, like Python.
+//!
+//! * **From Rust to C:** [`CString`] represents an owned, C-friendly
+//! string: it is nul-terminated, and has no internal nul characters.
+//! Rust code can create a `CString` out of a normal string (provided
+//! that the string doesn't have nul characters in the middle), and
+//! then use a variety of methods to obtain a raw `*mut u8` that can
+//! then be passed as an argument to functions which use the C
+//! conventions for strings.
+//!
+//! * **From C to Rust:** [`CStr`] represents a borrowed C string; it
+//! is what you would use to wrap a raw `*const u8` that you got from
+//! a C function. A `CStr` is guaranteed to be a nul-terminated array
+//! of bytes. Once you have a `CStr`, you can convert it to a Rust
+//! `&str` if it's valid UTF-8, or lossily convert it by adding
+//! replacement characters.
+//!
+//! [`OsString`] and [`OsStr`] are useful when you need to transfer
+//! strings to and from the operating system itself, or when capturing
+//! the output of external commands. Conversions between `OsString`,
+//! `OsStr` and Rust strings work similarly to those for [`CString`]
+//! and [`CStr`].
+//!
+//! * [`OsString`] represents an owned string in whatever
+//! representation the operating system prefers. In the Rust standard
+//! library, various APIs that transfer strings to/from the operating
+//! system use `OsString` instead of plain strings. For example,
+//! [`env::var_os()`] is used to query environment variables; it
+//! returns an `Option<OsString>`. If the environment variable exists
+//! you will get a `Some(os_string)`, which you can *then* try to
+//! convert to a Rust string. This yields a [`Result<>`], so that
+//! your code can detect errors in case the environment variable did
+//! not in fact contain valid Unicode data.
+//!
+//! * [`OsStr`] represents a borrowed reference to a string in a
+//! format that can be passed to the operating system. It can be
+//! converted into an UTF-8 Rust string slice in a similar way to
+//! `OsString`.
+//!
+//! # Conversions
+//!
+//! ## On Unix
+//!
+//! On Unix, [`OsStr`] implements the
+//! `std::os::unix:ffi::`[`OsStrExt`][unix.OsStrExt] trait, which
+//! augments it with two methods, [`from_bytes`] and [`as_bytes`].
+//! These do inexpensive conversions from and to UTF-8 byte slices.
+//!
+//! Additionally, on Unix [`OsString`] implements the
+//! `std::os::unix:ffi::`[`OsStringExt`][unix.OsStringExt] trait,
+//! which provides [`from_vec`] and [`into_vec`] methods that consume
+//! their arguments, and take or produce vectors of [`u8`].
+//!
+//! ## On Windows
+//!
+//! On Windows, [`OsStr`] implements the
+//! `std::os::windows::ffi::`[`OsStrExt`][windows.OsStrExt] trait,
+//! which provides an [`encode_wide`] method. This provides an
+//! iterator that can be [`collect`]ed into a vector of [`u16`].
+//!
+//! Additionally, on Windows [`OsString`] implements the
+//! `std::os::windows:ffi::`[`OsStringExt`][windows.OsStringExt]
+//! trait, which provides a [`from_wide`] method. The result of this
+//! method is an `OsString` which can be round-tripped to a Windows
+//! string losslessly.
+//!
+//! [`String`]: ../string/struct.String.html
+//! [`str`]: ../primitive.str.html
+//! [`char`]: ../primitive.char.html
+//! [`u8`]: ../primitive.u8.html
+//! [`u16`]: ../primitive.u16.html
+//! [Unicode scalar value]: http://www.unicode.org/glossary/#unicode_scalar_value
+//! [Unicode code point]: http://www.unicode.org/glossary/#code_point
+//! [`CString`]: struct.CString.html
+//! [`CStr`]: struct.CStr.html
+//! [`OsString`]: struct.OsString.html
+//! [`OsStr`]: struct.OsStr.html
+//! [`env::set_var()`]: ../env/fn.set_var.html
+//! [`env::var_os()`]: ../env/fn.var_os.html
+//! [`Result<>`]: ../result/enum.Result.html
+//! [unix.OsStringExt]: ../os/unix/ffi/trait.OsStringExt.html
+//! [`from_vec`]: ../os/unix/ffi/trait.OsStringExt.html#tymethod.from_vec
+//! [`into_vec`]: ../os/unix/ffi/trait.OsStringExt.html#tymethod.into_vec
+//! [unix.OsStrExt]: ../os/unix/ffi/trait.OsStrExt.html
+//! [`from_bytes`]: ../os/unix/ffi/trait.OsStrExt.html#tymethod.from_bytes
+//! [`as_bytes`]: ../os/unix/ffi/trait.OsStrExt.html#tymethod.as_bytes
+//! [`OsStrExt`]: ../os/unix/ffi/trait.OsStrExt.html
+//! [windows.OsStrExt]: ../os/windows/ffi/trait.OsStrExt.html
+//! [`encode_wide`]: ../os/windows/ffi/trait.OsStrExt.html#tymethod.encode_wide
+//! [`collect`]: ../iter/trait.Iterator.html#method.collect
+//! [windows.OsStringExt]: ../os/windows/ffi/trait.OsStringExt.html
+//! [`from_wide`]: ../os/windows/ffi/trait.OsStringExt.html#tymethod.from_wide
#![stable(feature = "rust1", since = "1.0.0")]
diff --git a/src/libstd/ffi/os_str.rs b/src/libstd/ffi/os_str.rs
index 88ee5c9a73420..a97075ff8d8cd 100644
--- a/src/libstd/ffi/os_str.rs
+++ b/src/libstd/ffi/os_str.rs
@@ -32,18 +32,65 @@ use sys_common::{AsInner, IntoInner, FromInner};
///
/// `OsString` and [`OsStr`] bridge this gap by simultaneously representing Rust
/// and platform-native string values, and in particular allowing a Rust string
-/// to be converted into an "OS" string with no cost.
+/// to be converted into an "OS" string with no cost if possible.
+///
+/// `OsString` is to [`OsStr`] as [`String`] is to [`&str`]: the former
+/// in each pair are owned strings; the latter are borrowed
+/// references.
+///
+/// # Creating an `OsString`
+///
+/// **From a Rust string**: `OsString` implements
+/// [`From`]`<`[`String`]`>`, so you can use `my_string.`[`from`] to
+/// create an `OsString` from a normal Rust string.
+///
+/// **From slices:** Just like you can start with an empty Rust
+/// [`String`] and then [`push_str`][String.push_str] `&str`
+/// sub-string slices into it, you can create an empty `OsString` with
+/// the [`new`] method and then push string slices into it with the
+/// [`push`] method.
+///
+/// # Extracting a borrowed reference to the whole OS string
+///
+/// You can use the [`as_os_str`] method to get an `&`[`OsStr`] from
+/// an `OsString`; this is effectively a borrowed reference to the
+/// whole string.
+///
+/// # Conversions
+///
+/// See the [module's toplevel documentation about conversions][conversions] for a discussion on
+/// the traits which `OsString` implements for conversions from/to native representations.
///
/// [`OsStr`]: struct.OsStr.html
+/// [`From`]: ../convert/trait.From.html
+/// [`from`]: ../convert/trait.From.html#tymethod.from
+/// [`String`]: ../string/struct.String.html
+/// [`&str`]: ../primitive.str.html
+/// [`u8`]: ../primitive.u8.html
+/// [`u16`]: ../primitive.u16.html
+/// [String.push_str]: ../string/struct.String.html#method.push_str
+/// [`new`]: #method.new
+/// [`push`]: #method.push
+/// [`as_os_str`]: #method.as_os_str
#[derive(Clone)]
#[stable(feature = "rust1", since = "1.0.0")]
pub struct OsString {
inner: Buf
}
-/// Slices into OS strings (see [`OsString`]).
+/// Borrowed reference to an OS string (see [`OsString`]).
+///
+/// This type represents a borrowed reference to a string in the operating system's preferred
+/// representation.
+///
+/// `OsStr` is to [`OsString`] as [`String`] is to [`&str`]: the former in each pair are borrowed
+/// references; the latter are owned strings.
+///
+/// See the [module's toplevel documentation about conversions][conversions] for a discussion on
+/// the traits which `OsStr` implements for conversions from/to native representations.
///
/// [`OsString`]: struct.OsString.html
+/// [conversions]: index.html#conversions
#[stable(feature = "rust1", since = "1.0.0")]
pub struct OsStr {
inner: Slice
diff --git a/src/libstd/sys/windows/ext/ffi.rs b/src/libstd/sys/windows/ext/ffi.rs
index 3f6c2827a3f93..d6b8896ac096d 100644
--- a/src/libstd/sys/windows/ext/ffi.rs
+++ b/src/libstd/sys/windows/ext/ffi.rs
@@ -9,6 +9,62 @@
// except according to those terms.
//! Windows-specific extensions to the primitives in the `std::ffi` module.
+//!
+//! # Overview
+//!
+//! For historical reasons, the Windows API uses a form of potentially
+//! ill-formed UTF-16 encoding for strings. Specifically, the 16-bit
+//! code units in Windows strings may contain [isolated surrogate code
+//! points which are not paired together][ill-formed-utf-16]. The
+//! Unicode standard requires that surrogate code points (those in the
+//! range U+D800 to U+DFFF) always be *paired*, because in the UTF-16
+//! encoding a *surrogate code unit pair* is used to encode a single
+//! character. For compatibility with code that does not enforce
+//! these pairings, Windows does not enforce them, either.
+//!
+//! While it is not always possible to convert such a string losslessly into
+//! a valid UTF-16 string (or even UTF-8), it is often desirable to be
+//! able to round-trip such a string from and to Windows APIs
+//! losslessly. For example, some Rust code may be "bridging" some
+//! Windows APIs together, just passing `WCHAR` strings among those
+//! APIs without ever really looking into the strings.
+//!
+//! If Rust code *does* need to look into those strings, it can
+//! convert them to valid UTF-8, possibly lossily, by substituting
+//! invalid sequences with U+FFFD REPLACEMENT CHARACTER, as is
+//! conventionally done in other Rust APIs that deal with string
+//! encodings.
+//!
+//! # `OsStringExt` and `OsStrExt`
+//!
+//! [`OsString`] is the Rust wrapper for owned strings in the
+//! preferred representation of the operating system. On Windows,
+//! this struct gets augmented with an implementation of the
+//! [`OsStringExt`] trait, which has a [`from_wide`] method. This
+//! lets you create an [`OsString`] from a `&[u16]` slice; presumably
+//! you get such a slice out of a `WCHAR` Windows API.
+//!
+//! Similarly, [`OsStr`] is the Rust wrapper for borrowed strings from
+//! preferred representation of the operating system. On Windows, the
+//! [`OsStrExt`] trait provides the [`encode_wide`] method, which
+//! outputs an [`EncodeWide`] iterator. You can [`collect`] this
+//! iterator, for example, to obtain a `Vec<u16>`; you can later get a
+//! pointer to this vector's contents and feed it to Windows APIs.
+//!
+//! These traits, along with [`OsString`] and [`OsStr`], work in
+//! conjunction so that it is possible to **round-trip** strings from
+//! Windows and back, with no loss of data, even if the strings are
+//! ill-formed UTF-16.
+//!
+//! [ill-formed-utf-16]: https://simonsapin.github.io/wtf-8/#ill-formed-utf-16
+//! [`OsString`]: ../../../ffi/struct.OsString.html
+//! [`OsStr`]: ../../../ffi/struct.OsStr.html
+//! [`OsStringExt`]: trait.OsStringExt.html
+//! [`OsStrExt`]: trait.OsStrExt.html
+//! [`EncodeWide`]: struct.EncodeWide.html
+//! [`from_wide`]: trait.OsStringExt.html#tymethod.from_wide
+//! [`encode_wide`]: trait.OsStrExt.html#tymethod.encode_wide
+//! [`collect`]: ../../../iter/trait.Iterator.html#method.collect
#![stable(feature = "rust1", since = "1.0.0")]
diff --git a/src/libsyntax/parse/parser.rs b/src/libsyntax/parse/parser.rs
index ff020445715d4..04e6cdcfe5820 100644
--- a/src/libsyntax/parse/parser.rs
+++ b/src/libsyntax/parse/parser.rs
@@ -2314,6 +2314,7 @@ impl<'a> Parser<'a> {
while self.token != token::CloseDelim(token::Brace) {
if self.eat(&token::DotDot) {
+ let exp_span = self.prev_span;
match self.parse_expr() {
Ok(e) => {
base = Some(e);
@@ -2323,6 +2324,16 @@ impl<'a> Parser<'a> {
self.recover_stmt();
}
}
+ if self.token == token::Comma {
+ let mut err = self.sess.span_diagnostic.mut_span_err(
+ exp_span.to(self.prev_span),
+ "cannot use a comma after the base struct",
+ );
+ err.span_suggestion_short(self.span, "remove this comma", "".to_owned());
+ err.note("the base struct must always be the last field");
+ err.emit();
+ self.recover_stmt();
+ }
break;
}
@@ -2960,6 +2971,7 @@ impl<'a> Parser<'a> {
{ // Foo<Bar<Baz<Qux, ()>>>
err.help(
"use `::<...>` instead of `<...>` if you meant to specify type arguments");
+ err.help("or use `(...)` if you meant to specify fn arguments");
}
err.emit();
}
diff --git a/src/llvm b/src/llvm
index c7a16bd57c2a9..83b72cedfd780 160000
--- a/src/llvm
+++ b/src/llvm
@@ -1 +1 @@
-Subproject commit c7a16bd57c2a9c643a52f0cebecdaf0b6a996da1
+Subproject commit 83b72cedfd7800ffc983d2855a85c5d06a545aa7
diff --git a/src/test/compile-fail/index-help.rs b/src/test/compile-fail/index-help.rs
new file mode 100644
index 0000000000000..2d37fc7925035
--- /dev/null
+++ b/src/test/compile-fail/index-help.rs
@@ -0,0 +1,15 @@
+// Copyright 2017 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+fn main() {
+ let x = vec![1];
+ x[0i32]; //~ ERROR E0277
+ //~| NOTE vector indices are of type `usize` or ranges of `usize`
+}
diff --git a/src/test/parse-fail/require-parens-for-chained-comparison.rs b/src/test/parse-fail/require-parens-for-chained-comparison.rs
index 7e76dbd31f0a3..1ee6996ce9c84 100644
--- a/src/test/parse-fail/require-parens-for-chained-comparison.rs
+++ b/src/test/parse-fail/require-parens-for-chained-comparison.rs
@@ -21,5 +21,6 @@ fn main() {
f<X>();
//~^ ERROR: chained comparison operators require parentheses
- //~^^ HELP: use `::<...>` instead of `<...>`
+ //~| HELP: use `::<...>` instead of `<...>`
+ //~| HELP: or use `(...)`
}
diff --git a/src/test/run-pass/smallest-hello-world.rs b/src/test/run-pass/smallest-hello-world.rs
deleted file mode 100644
index bcbd3fd3786ab..0000000000000
--- a/src/test/run-pass/smallest-hello-world.rs
+++ /dev/null
@@ -1,41 +0,0 @@
-// Copyright 2013-2014 The Rust Project Developers. See the COPYRIGHT
-// file at the top-level directory of this distribution and at
-// http://rust-lang.org/COPYRIGHT.
-//
-// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
-// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
-// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
-// option. This file may not be copied, modified, or distributed
-// except according to those terms.
-
-// Smallest "hello world" with a libc runtime
-
-// ignore-windows
-// ignore-android
-
-#![feature(intrinsics, lang_items, start, no_core, alloc_system)]
-#![feature(global_allocator, allocator_api)]
-#![no_std]
-
-extern crate alloc_system;
-
-use alloc_system::System;
-
-#[global_allocator]
-static A: System = System;
-
-extern {
- fn puts(s: *const u8);
-}
-
-#[no_mangle]
-#[lang = "eh_personality"] pub extern fn rust_eh_personality() {}
-#[lang = "panic_fmt"] fn panic_fmt() -> ! { loop {} }
-
-#[start]
-fn main(_: isize, _: *const *const u8) -> isize {
- unsafe {
- puts("Hello!\0".as_ptr() as *const u8);
- }
- return 0
-}
diff --git a/src/test/run-pass/thin-lto-global-allocator.rs b/src/test/run-pass/thin-lto-global-allocator.rs
new file mode 100644
index 0000000000000..1c15da5469e52
--- /dev/null
+++ b/src/test/run-pass/thin-lto-global-allocator.rs
@@ -0,0 +1,19 @@
+// Copyright 2017 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+// compile-flags: -Z thinlto -C codegen-units=2
+// min-llvm-version 4.0
+
+#![feature(allocator_api, global_allocator)]
+
+#[global_allocator]
+static A: std::heap::System = std::heap::System;
+
+fn main() {}
diff --git a/src/test/ui/did_you_mean/issue-40396.stderr b/src/test/ui/did_you_mean/issue-40396.stderr
index 1a0c74dc01a09..11279f5c6129f 100644
--- a/src/test/ui/did_you_mean/issue-40396.stderr
+++ b/src/test/ui/did_you_mean/issue-40396.stderr
@@ -5,6 +5,7 @@ error: chained comparison operators require parentheses
| ^^^^^^^^
|
= help: use `::<...>` instead of `<...>` if you meant to specify type arguments
+ = help: or use `(...)` if you meant to specify fn arguments
error: chained comparison operators require parentheses
--> $DIR/issue-40396.rs:16:25
@@ -13,6 +14,7 @@ error: chained comparison operators require parentheses
| ^^^^^^^
|
= help: use `::<...>` instead of `<...>` if you meant to specify type arguments
+ = help: or use `(...)` if you meant to specify fn arguments
error: chained comparison operators require parentheses
--> $DIR/issue-40396.rs:20:37
@@ -21,6 +23,7 @@ error: chained comparison operators require parentheses
| ^^^^^^^^
|
= help: use `::<...>` instead of `<...>` if you meant to specify type arguments
+ = help: or use `(...)` if you meant to specify fn arguments
error: chained comparison operators require parentheses
--> $DIR/issue-40396.rs:20:41
@@ -29,6 +32,7 @@ error: chained comparison operators require parentheses
| ^^^^^^
|
= help: use `::<...>` instead of `<...>` if you meant to specify type arguments
+ = help: or use `(...)` if you meant to specify fn arguments
error: aborting due to 4 previous errors
diff --git a/src/test/ui/struct-field-init-syntax.rs b/src/test/ui/struct-field-init-syntax.rs
new file mode 100644
index 0000000000000..8ea62fef9fad1
--- /dev/null
+++ b/src/test/ui/struct-field-init-syntax.rs
@@ -0,0 +1,27 @@
+// Copyright 2017 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+// compile-flags: -Z parse-only
+
+// issue #41834
+
+fn main() {
+ let foo = Foo {
+ one: 111,
+ ..Foo::default(),
+ //~^ ERROR cannot use a comma after struct expansion
+ };
+
+ let foo = Foo {
+ ..Foo::default(),
+ //~^ ERROR cannot use a comma after struct expansion
+ one: 111,
+ };
+}
diff --git a/src/test/ui/struct-field-init-syntax.stderr b/src/test/ui/struct-field-init-syntax.stderr
new file mode 100644
index 0000000000000..0bca3f83eb1a3
--- /dev/null
+++ b/src/test/ui/struct-field-init-syntax.stderr
@@ -0,0 +1,18 @@
+error: cannot use a comma after the base struct
+ --> $DIR/struct-field-init-syntax.rs:18:9
+ |
+18 | ..Foo::default(),
+ | ^^^^^^^^^^^^^^^^- help: remove this comma
+ |
+ = note: the base struct must always be the last field
+
+error: cannot use a comma after the base struct
+ --> $DIR/struct-field-init-syntax.rs:23:9
+ |
+23 | ..Foo::default(),
+ | ^^^^^^^^^^^^^^^^- help: remove this comma
+ |
+ = note: the base struct must always be the last field
+
+error: aborting due to 2 previous errors
+
diff --git a/src/test/ui/suggestions/closure-immutable-outer-variable.rs b/src/test/ui/suggestions/closure-immutable-outer-variable.rs
new file mode 100644
index 0000000000000..fe8e2bc6c8ed1
--- /dev/null
+++ b/src/test/ui/suggestions/closure-immutable-outer-variable.rs
@@ -0,0 +1,20 @@
+// Copyright 2017 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+// Point at the captured immutable outer variable
+
+fn foo(mut f: Box<FnMut()>) {
+ f();
+}
+
+fn main() {
+ let y = true;
+ foo(Box::new(move || y = false) as Box<_>);
+}
diff --git a/src/test/ui/suggestions/closure-immutable-outer-variable.stderr b/src/test/ui/suggestions/closure-immutable-outer-variable.stderr
new file mode 100644
index 0000000000000..19f1cd071714e
--- /dev/null
+++ b/src/test/ui/suggestions/closure-immutable-outer-variable.stderr
@@ -0,0 +1,10 @@
+error[E0594]: cannot assign to captured outer variable in an `FnMut` closure
+ --> $DIR/closure-immutable-outer-variable.rs:19:26
+ |
+18 | let y = true;
+ | - help: consider making `y` mutable: `mut y`
+19 | foo(Box::new(move || y = false) as Box<_>);
+ | ^^^^^^^^^
+
+error: aborting due to previous error
+
diff --git a/src/test/ui/suggestions/suggest-labels.rs b/src/test/ui/suggestions/suggest-labels.rs
new file mode 100644
index 0000000000000..5bebce79eccbc
--- /dev/null
+++ b/src/test/ui/suggestions/suggest-labels.rs
@@ -0,0 +1,26 @@
+// Copyright 2017 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+#[allow(unreachable_code)]
+fn main() {
+ 'foo: loop {
+ break 'fo;
+ }
+
+ 'bar: loop {
+ continue 'bor;
+ }
+
+ 'longlabel: loop {
+ 'longlabel1: loop {
+ break 'longlable;
+ }
+ }
+}
diff --git a/src/test/ui/suggestions/suggest-labels.stderr b/src/test/ui/suggestions/suggest-labels.stderr
new file mode 100644
index 0000000000000..23aa18a3655fb
--- /dev/null
+++ b/src/test/ui/suggestions/suggest-labels.stderr
@@ -0,0 +1,20 @@
+error[E0426]: use of undeclared label `'fo`
+ --> $DIR/suggest-labels.rs:14:15
+ |
+14 | break 'fo;
+ | ^^^ did you mean `'foo`?
+
+error[E0426]: use of undeclared label `'bor`
+ --> $DIR/suggest-labels.rs:18:18
+ |
+18 | continue 'bor;
+ | ^^^^ did you mean `'bar`?
+
+error[E0426]: use of undeclared label `'longlable`
+ --> $DIR/suggest-labels.rs:23:19
+ |
+23 | break 'longlable;
+ | ^^^^^^^^^^ did you mean `'longlabel1`?
+
+error: aborting due to 3 previous errors
+