If #[feature(default_type_parameters)] is enabled for a crate, then
deriving(Hash) will expand with Hash<W: Writer> instead of Hash<SipState> so
more hash algorithms can be used.
This leverages the new hashing framework and hashmap implementation to provide a
much speedier hashing algorithm for node ids and def ids. The hash algorithm
used is currentl FNV hashing, but it's quite easy to swap out.
I originally implemented hashing as the identity function, but this actually
ended up in slowing down rustc compiling libstd from 8s to 13s. I would suspect
that this is a result of a large number of collisions.
With FNV hashing, we get these timings (compiling with --no-trans, in seconds):
| | before | after |
|-----------|---------:|--------:|
| libstd | 8.324 | 6.703 |
| stdtest | 47.674 | 46.857 |
| libsyntax | 9.918 | 8.400 |
I added a new lint for variables whose names contain uppercase characters, since, by convention, variable names should be all lowercase. What motivated me to work on this was when I ran into something like the following:
```rust
use std::io::File;
use std::io::IoError;
fn main() {
let mut f = File::open(&Path::new("/something.txt"));
let mut buff = [0u8, ..16];
match f.read(buff) {
Ok(cnt) => println!("read this many bytes: {}", cnt),
Err(IoError{ kind: EndOfFile, .. }) => println!("Got end of file: {}", EndOfFile.to_str()),
}
}
```
I then got compile errors when I tried to add a wildcard match pattern at the end which I found very confusing since I believed that the 2nd match arm was only matching the EndOfFile condition. The problem is that I hadn't imported io::EndOfFile into the local scope. So, I thought that I was using EndOfFile as a sub-pattern, however, what I was actually doing was creating a new local variable named EndOfFile. This lint makes this error easier to spot by providing a warning that the variable name EndOfFile contains a uppercase characters which provides a nice hint as to why the code isn't doing what is intended.
The lint warns on local bindings as well:
```rust
let Hi = 0;
```
And also struct fields:
```rust
struct Something {
X: uint
}
```
Previously `ast::Arm` was always storing a single `ast::Expr` wrapped in an
`ast::Block` (for historical reasons, AIUI), so we might as just store
that expr directly.
Closes#3085.
A couple of syntax extensions manually expanded expressions, but it
wasn't done universally, most noticably inside of asm!().
There's also a bit of random cleanup.
Similarly to #12422 which made stdin buffered by default, this commit makes the
output streams also buffered by default. Now that buffered writers will flush
their contents when they are dropped, I don't believe that there's no reason why
the output shouldn't be buffered by default, which is what you want in 90% of
cases.
As with stdin, there are new stdout_raw() and stderr_raw() functions to get
unbuffered streams to stdout/stderr.
Formatting via reflection has been a little questionable for some time now, and
it's a little unfortunate that one of the standard macros will silently use
reflection when you weren't expecting it. This adds small bits of code bloat to
libraries, as well as not always being necessary. In light of this information,
this commit switches assert_eq!() to using {} in the error message instead of
{:?}.
In updating existing code, there were a few error cases that I encountered:
* It's impossible to define Show for [T, ..N]. I think DST will alleviate this
because we can define Show for [T].
* A few types here and there just needed a #[deriving(Show)]
* Type parameters needed a Show bound, I often moved this to `assert!(a == b)`
* `Path` doesn't implement `Show`, so assert_eq!() cannot be used on two paths.
I don't think this is much of a regression though because {:?} on paths looks
awful (it's a byte array).
Concretely speaking, this shaved 10K off a 656K binary. Not a lot, but sometime
significant for smaller binaries.
This helps prevent interleaving of error messages when running rustdoc tests.
This has an interesting bit of shuffling with I/O handles, but other than that
this is just using the APIs laid out in the previous commit.
Closes#12623
This commit alters the diagnostic emission machinery to be focused around a
Writer for emitting errors. This allows it to not hard-code emission of errors
to stderr (useful for other applications).
Previously, format!("{a}{b}", a=foo(), b=bar()) has foo() and bar() run in a
nondeterminisc order. This is clearly a non-desirable property, so this commit
uses iteration over a list instead of iteration over a hash map to provide
deterministic code generation of these format arguments.
The previous code passed around a {name,version} pair everywhere, but this is
better expressed as a CrateId. This patch changes these paths to store and pass
around crate ids instead of these pairs of name/version. This also prepares the
code to change the type of hash that is stored in crates.
There's a lot of these types in the compiler libraries, and a few of the
older or private stdlib ones. Some types are obviously meant to be
public, others not so much.
These are types that are in exported type signatures, but are not
exported themselves, e.g.
struct Foo { ... }
pub fn bar() -> Foo { ... }
will warn about the Foo.
Such types are not listed in documentation, and cannot be named outside
the crate in which they are declared, which is very user-unfriendly.
cc #10573
Make bytepos_to_charpos relative to the start of the filemap rather than its previous behaviour which was to be realtive to the start of the codemap, but ignoring multi-byte chars in earlier filemaps. Rename to bytepos_to_file_charpos. Add tests for multi-byte chars.
The most significant fix is for `syntax::ext::deriving::encodable`,
where one of the blocks of code, auspiciously containing `<S>` (recall
that Markdown allows arbitrary HTML to be contained inside it), was not
formatted as a code block, with a fun but messy effect.
The pretty printer was treating block comments with more than two
asterisks after the first slash (e.g. `/***`) as doc comments (which are
attributes), whereas in actual fact they are just regular comments.
This patch series does a couple things:
* replaces manual `Hash` implementations with `#[deriving(Hash)]`
* adds `Hash` back to `std::prelude`
* minor cleanup of whitespace and variable names.
They are still are not completely correct, since it does not handle
graphemes at all, just codepoints, but at least it handles the common
case correctly.
The calculation was previously very wrong (rather than just a little bit
wrong): it wasn't accounting for the fact that every character is 1
byte, and so multibyte characters were pretending to be zero width.
cc #8706
file.
Previously multibyte UTF-8 chars were being recorded as byte offsets
from the start of the file, and then later compared against global byte
positions, resulting in the compiler possibly thinking it had a byte
position pointing inside a multibyte character, if there were multibyte
characters in any non-crate files. (Although, sometimes the byte offsets
line up just right to not ICE, but that was a coincidence.)
Fixes#11136.
Fixes#11178.
This commit removes deriving(ToStr) in favor of deriving(Show), migrating all impls of ToStr to fmt::Show.
Most of the details can be found in the first commit message.
Closes#12477
This commit changes the ToStr trait to:
impl<T: fmt::Show> ToStr for T {
fn to_str(&self) -> ~str { format!("{}", *self) }
}
The ToStr trait has been on the chopping block for quite awhile now, and this is
the final nail in its coffin. The trait and the corresponding method are not
being removed as part of this commit, but rather any implementations of the
`ToStr` trait are being forbidden because of the generic impl. The new way to
get the `to_str()` method to work is to implement `fmt::Show`.
Formatting into a `&mut Writer` (as `format!` does) is much more efficient than
`ToStr` when building up large strings. The `ToStr` trait forces many
intermediate allocations to be made while the `fmt::Show` trait allows
incremental buildup in the same heap allocated buffer. Additionally, the
`fmt::Show` trait is much more extensible in terms of interoperation with other
`Writer` instances and in more situations. By design the `ToStr` trait requires
at least one allocation whereas the `fmt::Show` trait does not require any
allocations.
Closes#8242Closes#9806
Makes labelled loops hygiene by performing renaming of the labels defined in e.g. `'x: loop { ... }` and then used in break and continue statements within loop body so that they act hygienically when used with macros.
Closes#12262.
