The way we deal with unreachable expressions in trans is pretty ad hoc,
but this at least doesn't make it worse, and eliminates the LLVM
assertion failure reported in #5741.
Fixes https://github.com/mozilla/rust/issues/6578 by merging the 3 different ways to build an AST into a single `AstBuilder` trait, creating a more uniform and briefer interface.
Also, converts the `ext_ctxt` trait-object to be a plain struct, as well as renaming it to `ExtCtxt`.
Seems to make expansion slightly faster for the normal case (e.g. `libcore` and `libstd`), but slower for `librustc` (slightly) and `libsyntax` (0.3s -> 0.8s! I'm investigating this, but I'd prefer this patch to land relatively quickly.).
`git blame` suggests maybe @graydon or @erickt are familiar with this area of the code. r?
This adds a lint mode for detecting unnecessary allocations on the heap. This isn't super fancy, currently it only has two rules
1. For a function's arguments, if you allocate a `[~|@]str` literal, when the type of the argument is a `&str`, emit a warning.
2. For the same case, emit warnings for boxed vectors when slices are required.
After adding the lint, I rampaged through the libraries and removed all the unnecessary allocations I could find.
r?
Mostly refactoring, and adding some of the remaining types described in #4419.
The [`Local`](3b4ff41511/src/libcore/rt/local.rs (L17)) trait collects some common, often unsafe patterns around task-local and thread-local values. Making all these types safe is largely the aim of #6210.
* Add ARC::get method and implements the function from it.
* Add an example showing a simple use of ARC.
Update PR #6622 to avoid git noise.
I will remove the function get later.
This includes new, tested, hygiene support functions. It also removes the interner_key! macro and replaces it with a function, which should be inline-able. It also contains some parser patch-ups and some docfixes.
On my machine, this patch passes all tests.
