borrow checker and generalize what moves are allowed. Fixes a nasty
bug or two in the pattern move checking code. Unifies dataflow code
used for initialization and other things. First step towards
once fns. Everybody wins.
Fixes#4384. Fixes#4715. cc once fns (#2202), optimizing local moves (#5016).
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.
Currently, trait_info is a hashmap that allows a quick lookup of all
methods contained in a given trait, but we actually only use it to
lookup traits that contain a given method. Adjusting the map to support
the lookup we actually need gives a nice speed boost, reducing the time
required for the resolution step for librustc from ~2.6s to ~1.0s on my
box.
fail!() used to require owned strings but can handle static strings
now. Also, it can pass its arguments to fmt!() on its own, no need for
the caller to call fmt!() itself.
Every unresolved import is reported. An additional error message isn't useful
and obscures (imo) the real errors: I need to take it into account when
looking at the error count.
Closes#6183.
The first commit changes the compiler's method of treating a `for` loop, and all the remaining commits are just dealing with the fallout.
The biggest fallout was the `IterBytes` trait, although it's really a whole lot nicer now because all of the `iter_bytes_XX` methods are just and-ed together. Sadly there was a huge amount of stuff that's `cfg(stage0)` gated, but whoever lands the next snapshot is going to have a lot of fun deleting all this code!
&str can be turned into @~str on demand, using to_owned(), so for
strings, we can create a specialized interner that accepts &str for
intern() and find() but stores and returns @~str.
This improves error reporting for the following class of imports:
```rust
use foo::bar;
```
Where foo, the topmost module, is unresolved. It now results in:
```text
/tmp/foo.rs:1:4: 1:7 error: unresolved import. perhapsyou forgot an 'extern mod foo'?
/tmp/foo.rs:1 use foo::bar;
^~~
/tmp/foo.rs:1:4: 1:12 error: failed to resolve import: foo::bar
/tmp/foo.rs:1 use foo::bar;
^~~~~~~~
error: failed to resolve imports
error: aborting due to 3 previous errors
```
This is the first of a series of changes I plan on making to unresolved name error messages.
