In most cases this involved removing a ~str allocations or clones
(yay), or coercing a ~str to a slice. In a few places, I had to bind
an intermediate Path (e.g. path.pop() return values), so that it would
live long enough to support the borrowed &str.
And in a few places, where the code was actively using the property
that the old API returned ~str's, I had to put in to_owned() or
clone(); but in those cases, we're trading an allocation within the
path.rs code for one in the client code, so they neutralize each
other.
Note that I left dirname as returning ~str, because both of its
implementations work by calling dir_path, which produces a new path,
and thus we cannot borrow the result from &'a self passed to dirname
(because the new path returned by dir_path will not live long enough
to satisfy the lifetime 'a).
Several changes with appropriate commit messages to explain them.
The final two commits, highlighting everything in the prelude, may be a little controversial. I think it's the sensible way forward with it.
We already do this for libstd tests automatically, and compiletest runs into the
same problems where when forking lots of processes lots of file descriptors are
created. On OSX we can use specific syscalls to raise the limits, in this
situation, though.
Closes#8904
Current access methods are nestable and unsafe. This patch renames
current methods implementation - prepends unsafe_ - and implements 2 new
methods that are both safe and un-nestable.
Fixes#7473
The Listener trait takes two type parameters, the type of connection and the type of Acceptor,
and specifies only one method, listen, which consumes the listener and produces an Acceptor.
The Acceptor trait takes one type parameter, the type of connection, and defines two methods.
The accept() method waits for an incoming connection attempt and returns the result.
The incoming() method creates an iterator over incoming connections and is a default method.
Example:
```rust
let listener = TcpListener.bind(addr); // Bind to a socket
let acceptor = listener.listen(); // Start the listener
for stream in acceptor.incoming() {
// Process incoming connections forever (a failure will kill the task).
}
```
Closes#8689
Significant progress on #6875, enough that I'll open new bugs and turn that into a metabug when this lands.
Description & example in the commit message.
I added a few and removed a few and corrected a couple, all with
reference to the prelude. It ends up a slightly arbitrary decision
precisely what ends up in and what doesn't, unfortunately.
- Remove highlighting of ``L"..."`` (obsolete syntax)
- Remove backslash at end of line being a line continuation always
(obsolete syntax; this only affects comments, actually)
- Add highlighting for backslash at end of line and leading whitespace
on the following line inside a string (a genuine line continuation)
Storing the type name in the `tydesc` aims to avoid the need to pass a type name in almost every single visitor method.
It would likely be much saner for `repr` to simply be passed the `TyDesc` corresponding to the function or just the type name, but this is good enough for now.
There are 6 new compiler recognised attributes: deprecated, experimental,
unstable, stable, frozen, locked (these levels are taken directly from
Node's "stability index"[1]). These indicate the stability of the
item to which they are attached; e.g. `#[deprecated] fn foo() { .. }`
says that `foo` is deprecated.
This comes with 3 lints for the first 3 levels (with matching names) that
will detect the use of items marked with them (the `unstable` lint
includes items with no stability attribute). The attributes can be given
a short text note that will be displayed by the lint. An example:
#[warn(unstable)]; // `allow` by default
#[deprecated="use `bar`"]
fn foo() { }
#[stable]
fn bar() { }
fn baz() { }
fn main() {
foo(); // "warning: use of deprecated item: use `bar`"
bar(); // all fine
baz(); // "warning: use of unmarked item"
}
The lints currently only check the "edges" of the AST: i.e. functions,
methods[2], structs and enum variants. Any stability attributes on modules,
enums, traits and impls are not checked.
[1]: http://nodejs.org/api/documentation.html
[2]: the method check is currently incorrect and doesn't work.
The message of the first commit explains (edited for changed trait name):
The trait `ExactSize` is introduced to solve a few small niggles:
* We can't reverse (`.invert()`) an enumeration iterator
* for a vector, we have `v.iter().position(f)` but `v.rposition(f)`.
* We can't reverse `Zip` even if both iterators are from vectors
`ExactSize` is an empty trait that is intended to indicate that an
iterator, for example `VecIterator`, knows its exact finite size and
reports it correctly using `.size_hint()`. Only adaptors that preserve
this at all times, can expose this trait further. (Where here we say
finite for fitting in uint).
---
It may seem complicated just to solve these small "niggles",
(It's really the reversible enumerate case that's the most interesting)
but only a few core iterators need to implement this trait.
While we gain more capabilities generically for some iterators,
it becomes a tad more complicated to figure out if a type has
the right trait impls for it.
Fix#8468. (Though the right answer in the end, as noted on the dialogue on the ticket, might be to just require trait methods to name their parameters, regardless of whether they have a default method implementation or not.)
As with the previous commit, this is targeted at removing the possibility of
collisions between statics. The main use case here is when there's a
type-parametric function with an inner static that's compiled as a library.
Before this commit, any impl would generate a path item of "__extensions__".
This changes this identifier to be a "pretty name", which is either the last
element of the path of the trait implemented or the last element of the type's
path that's being implemented. That doesn't quite cut it though, so the (trait,
type) pair is hashed and again used to append information to the symbol.
Essentially, __extensions__ was removed for something nicer for debugging, and
then some more information was added to symbol name by including a hash of the
trait being implemented and type it's being implemented for. This should prevent
colliding names for inner statics in regular functions with similar names.
Before, the path name for all items defined in methods of traits and impls never
took into account the name of the method. This meant that if you had two statics
of the same name in two different methods the statics would end up having the
same symbol named (even after mangling) because the path components leading to
the symbol were exactly the same (just __extensions__ and the static name).
It turns out that if you add the symbol "A" twice to LLVM, it automatically
makes the second one "A1" instead of "A". What this meant is that in local crate
compilations we never found this bug. Even across crates, this was never a
problem. The problem arises when you have generic methods that don't get
generated at compile-time of a library. If the statics were re-added to LLVM by
a client crate of a library in a different order, you would reference different
constants (the integer suffixes wouldn't be guaranteed to be the same).
This fixes the problem by adding the method name to symbol path when building
the ast_map. In doing so, two symbols in two different methods are disambiguated
against.
