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.
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.
These two containers are indeed collections, so their place is in
libcollections, not in libstd. There will always be a hash map as part of the
standard distribution of Rust, but by moving it out of the standard library it
makes libstd that much more portable to more platforms and environments.
This conveniently also removes the stuttering of 'std::hashmap::HashMap',
although 'collections::HashMap' is only one character shorter.
This PR merges `IterBytes` and `Hash` into a trait that allows for generic non-stream-based hashing. It makes use of @eddyb's default type parameter support in order to have a similar usage to the old `Hash` framework.
Fixes#8038.
Todo:
- [x] Better documentation
- [ ] Benchmark
- [ ] Parameterize `HashMap` on a `Hasher`.
Closes#12366.
Parentheses around assignment statements such as
let mut a = (0);
a = (1);
a += (2);
are not necessary and therefore an unnecessary_parens warning is raised when
statements like this occur.
The warning mechanism was refactored along the way to allow for code reuse
between the routines for checking expressions and statements.
Code had to be adopted throughout the compiler and standard libraries to comply
with this modification of the lint.
This patch merges IterBytes and Hash traits, which clears up the
confusion of using `#[deriving(IterBytes)]` to support hashing.
Instead, it now is much easier to use the new `#[deriving(Hash)]`
for making a type hashable with a stream hash.
Furthermore, it supports custom non-stream-based hashers, such as
if a value's hash was cached in a database.
This does not yet replace the old IterBytes-hash with this new
version.
This is in preparation to remove the implementations of ToStrRadix in integers, and to remove the associated logic from `std::num::strconv`.
The parts that still need to be liberated are:
- `std::fmt::Formatter::runplural`
- `num::{bigint, complex, rational}`
This "bubble up an error" macro was originally named if_ok! in order to get it
landed, but after the fact it was discovered that this name is not exactly
desirable.
The name `if_ok!` isn't immediately clear that is has much to do with error
handling, and it doesn't look fantastic in all contexts (if if_ok!(...) {}). In
general, the agreed opinion about `if_ok!` is that is came in as subpar.
The name `try!` is more invocative of error handling, it's shorter by 2 letters,
and it looks fitting in almost all circumstances. One concern about the word
`try!` is that it's too invocative of exceptions, but the belief is that this
will be overcome with documentation and examples.
Close#12037
Currently, the format_args! macro and its downstream macros in turn
expand to series of let statements, one for each of its arguments, and
then the invocation of the macro function. If one or more of the
arguments are RefCell's, the enclosing statement for the temporary of
the let is the let itself, which leads to scope problem. This patch
changes let's to a match expression.
Closes#12239.
Currently, the format_args! macro and its downstream macros in turn
expand to series of let statements, one for each of its arguments, and
then the invocation of the macro function. If one or more of the
arguments are RefCell's, the enclosing statement for the temporary of
the let is the let itself, which leads to scope problem. This patch
changes let's to a match expression.
Closes#12239.
Closes#11692. Instead of returning the original expression, a dummy expression
(with identical span) is returned. This prevents infinite loops of failed
expansions as well as odd double error messages in certain situations.
Now that fold_item can return multiple items, this is pretty trivial. It
also recursively expands generated items so ItemDecorators can generate
items that are tagged with ItemDecorators!
Closes#4913
The old method of building up a list of items and threading it through
all of the decorators was unwieldy and not really scalable as
non-deriving ItemDecorators become possible. The API is now that the
decorator gets an immutable reference to the item it's attached to, and
a callback that it can pass new items to. If we want to add syntax
extensions that can modify the item they're attached to, we can add that
later, but I think it'll have to be separate from ItemDecorator to avoid
strange ordering issues.
@huonw
The old method of building up a list of items and threading it through
all of the decorators was unwieldy and not really scalable as
non-deriving ItemDecorators become possible. The API is now that the
decorator gets an immutable reference to the item it's attached to, and
a callback that it can pass new items to. If we want to add syntax
extensions that can modify the item they're attached to, we can add that
later, but I think it'll have to be separate from ItemDecorator to avoid
strange ordering issues.
The first setp for #9880 is to add a new `crate` keyword. This PR does exactly that. I took a chance to refactor `parse_item_foreign_mod` and I broke it down into 2 separate methods to isolate each feature.
The next step will be to push a new stage0 snapshot and then get rid of all `extern mod` around the code.
Externally loaded libraries are able to do things that cause references
to them to survive past the expansion phase (e.g. creating @-box cycles,
launching a task or storing something in task local data). As such, the
library has to stay loaded for the lifetime of the process.
This patch gets rid of ObsoleteExternModAttributesInParens and
ObsoleteNamedExternModule since the replacement of `extern mod` with
`extern crate` avoids those cases and raises different errors. Both have
been around for at least a version which makes this a good moment to get
rid of them.
This patch adds a new keyword `crate` which is intended to replace mod
in the context of `extern mod` as part of the issue #9880. The patch
doesn't replace all `extern mod` cases since it is necessary to first
push a new snapshot 0.
The implementation could've been less invasive than this. However I
preferred to take this chance to split the `parse_item_foreign_mod`
method and pull the `extern crate` part out of there, hence the new
method `parse_item_foreign_crate`.
This patch replaces all `crate` usage with `krate` before introducing the
new keyword. This ensures that after introducing the keyword, there
won't be any compilation errors.
krate might not be the most expressive substitution for crate but it's a
very close abbreviation for it. `module` was already used in several
places already.
This resolves issue #12157. Does that do it already or is there something else that needs taking care of?
As a side note, there seems to be some documentation, in which the old existence of the do keyword is explained. The list of keywords is not up-to-date either. But these are certainly separate issues.
Resolves issue #12157. `do` is hereby reinstated as a keyword; no syntax is
associated with it though. Along the way, a unit test had to be adapted, since
it was using `do` as a method identifier.
Breaking changes:
- Any code using `do` as an identifier will no longer work.
Repair a rather embarassingly obvious hole that I created as part of #9629. In particular, prevent `&mut` borrows of data in an aliasable location. This used to be prevented through the restrictions mechanism, but in #9629 I modified those rules incorrectly.
r? @pcwalton
Fixes#11913
fourcc!() allows you to embed FourCC (or OSType) values that are
evaluated as u32 literals. It takes a 4-byte ASCII string and produces
the u32 resulting in interpreting those 4 bytes as a u32, using either
the platform-native endianness, or explicitly as big or little endian.
Error messages cleaned in librustc/middle
Error messages cleaned in libsyntax
Error messages cleaned in libsyntax more agressively
Error messages cleaned in librustc more aggressively
Fixed affected tests
Fixed other failing tests
Last failing tests fixed
The lexer and json were using `transmute(-1): char` as a sentinel value for EOF, which is invalid since `char` is strictly a unicode codepoint.
Fixing this allows for range asserts on chars since they always lie between 0 and 0x10FFFF.
The transmute was unsound.
There are many instances of .unwrap_or('\x00') for "ignoring" EOF which
either do not make the situation worse than it was (well, actually make
it better, since it's easy to grep for places that don't handle EOF) or
can never ever be read.
Fixes#8971.
This has been a long time coming. Conditions in rust were initially envisioned
as being a good alternative to error code return pattern. The idea is that all
errors are fatal-by-default, and you can opt-in to handling the error by
registering an error handler.
While sounding nice, conditions ended up having some unforseen shortcomings:
* Actually handling an error has some very awkward syntax:
let mut result = None;
let mut answer = None;
io::io_error::cond.trap(|e| { result = Some(e) }).inside(|| {
answer = Some(some_io_operation());
});
match result {
Some(err) => { /* hit an I/O error */ }
None => {
let answer = answer.unwrap();
/* deal with the result of I/O */
}
}
This pattern can certainly use functions like io::result, but at its core
actually handling conditions is fairly difficult
* The "zero value" of a function is often confusing. One of the main ideas
behind using conditions was to change the signature of I/O functions. Instead
of read_be_u32() returning a result, it returned a u32. Errors were notified
via a condition, and if you caught the condition you understood that the "zero
value" returned is actually a garbage value. These zero values are often
difficult to understand, however.
One case of this is the read_bytes() function. The function takes an integer
length of the amount of bytes to read, and returns an array of that size. The
array may actually be shorter, however, if an error occurred.
Another case is fs::stat(). The theoretical "zero value" is a blank stat
struct, but it's a little awkward to create and return a zero'd out stat
struct on a call to stat().
In general, the return value of functions that can raise error are much more
natural when using a Result as opposed to an always-usable zero-value.
* Conditions impose a necessary runtime requirement on *all* I/O. In theory I/O
is as simple as calling read() and write(), but using conditions imposed the
restriction that a rust local task was required if you wanted to catch errors
with I/O. While certainly an surmountable difficulty, this was always a bit of
a thorn in the side of conditions.
* Functions raising conditions are not always clear that they are raising
conditions. This suffers a similar problem to exceptions where you don't
actually know whether a function raises a condition or not. The documentation
likely explains, but if someone retroactively adds a condition to a function
there's nothing forcing upstream users to acknowledge a new point of task
failure.
* Libaries using I/O are not guaranteed to correctly raise on conditions when an
error occurs. In developing various I/O libraries, it's much easier to just
return `None` from a read rather than raising an error. The silent contract of
"don't raise on EOF" was a little difficult to understand and threw a wrench
into the answer of the question "when do I raise a condition?"
Many of these difficulties can be overcome through documentation, examples, and
general practice. In the end, all of these difficulties added together ended up
being too overwhelming and improving various aspects didn't end up helping that
much.
A result-based I/O error handling strategy also has shortcomings, but the
cognitive burden is much smaller. The tooling necessary to make this strategy as
usable as conditions were is much smaller than the tooling necessary for
conditions.
Perhaps conditions may manifest themselves as a future entity, but for now
we're going to remove them from the standard library.
Closes#9795Closes#8968
This has been a long time coming. Conditions in rust were initially envisioned
as being a good alternative to error code return pattern. The idea is that all
errors are fatal-by-default, and you can opt-in to handling the error by
registering an error handler.
While sounding nice, conditions ended up having some unforseen shortcomings:
* Actually handling an error has some very awkward syntax:
let mut result = None;
let mut answer = None;
io::io_error::cond.trap(|e| { result = Some(e) }).inside(|| {
answer = Some(some_io_operation());
});
match result {
Some(err) => { /* hit an I/O error */ }
None => {
let answer = answer.unwrap();
/* deal with the result of I/O */
}
}
This pattern can certainly use functions like io::result, but at its core
actually handling conditions is fairly difficult
* The "zero value" of a function is often confusing. One of the main ideas
behind using conditions was to change the signature of I/O functions. Instead
of read_be_u32() returning a result, it returned a u32. Errors were notified
via a condition, and if you caught the condition you understood that the "zero
value" returned is actually a garbage value. These zero values are often
difficult to understand, however.
One case of this is the read_bytes() function. The function takes an integer
length of the amount of bytes to read, and returns an array of that size. The
array may actually be shorter, however, if an error occurred.
Another case is fs::stat(). The theoretical "zero value" is a blank stat
struct, but it's a little awkward to create and return a zero'd out stat
struct on a call to stat().
In general, the return value of functions that can raise error are much more
natural when using a Result as opposed to an always-usable zero-value.
* Conditions impose a necessary runtime requirement on *all* I/O. In theory I/O
is as simple as calling read() and write(), but using conditions imposed the
restriction that a rust local task was required if you wanted to catch errors
with I/O. While certainly an surmountable difficulty, this was always a bit of
a thorn in the side of conditions.
* Functions raising conditions are not always clear that they are raising
conditions. This suffers a similar problem to exceptions where you don't
actually know whether a function raises a condition or not. The documentation
likely explains, but if someone retroactively adds a condition to a function
there's nothing forcing upstream users to acknowledge a new point of task
failure.
* Libaries using I/O are not guaranteed to correctly raise on conditions when an
error occurs. In developing various I/O libraries, it's much easier to just
return `None` from a read rather than raising an error. The silent contract of
"don't raise on EOF" was a little difficult to understand and threw a wrench
into the answer of the question "when do I raise a condition?"
Many of these difficulties can be overcome through documentation, examples, and
general practice. In the end, all of these difficulties added together ended up
being too overwhelming and improving various aspects didn't end up helping that
much.
A result-based I/O error handling strategy also has shortcomings, but the
cognitive burden is much smaller. The tooling necessary to make this strategy as
usable as conditions were is much smaller than the tooling necessary for
conditions.
Perhaps conditions may manifest themselves as a future entity, but for now
we're going to remove them from the standard library.
Closes#9795Closes#8968
- `extra::json` didn't make the cut, because of `extra::json` required
dep on `extra::TreeMap`. If/when `extra::TreeMap` moves out of `extra`,
then `extra::json` could move into `serialize`
- `libextra`, `libsyntax` and `librustc` depend on the newly created
`libserialize`
- The extensions to various `extra` types like `DList`, `RingBuf`, `TreeMap`
and `TreeSet` for `Encodable`/`Decodable` were moved into the respective
modules in `extra`
- There is some trickery, evident in `src/libextra/lib.rs` where a stub
of `extra::serialize` is set up (in `src/libextra/serialize.rs`) for
use in the stage0 build, where the snapshot rustc is still making
deriving for `Encodable` and `Decodable` point at extra. Big props to
@huonw for help working out the re-export solution for this
extra: inline extra::serialize stub
fix stuff clobbered in rebase + don't reexport serialize::serialize
no more globs in libserialize
syntax: fix import of libserialize traits
librustc: fix bad imports in encoder/decoder
add serialize dep to librustdoc
fix failing run-pass tests w/ serialize dep
adjust uuid dep
more rebase de-clobbering for libserialize
fixing tests, pushing libextra dep into cfg(test)
fix doc code in extra::json
adjust index.md links to serialize and uuid library
This removes @[] from the parser as well as much of the handling of it (and `@str`) from the compiler as I can find.
I've just rebased @pcwalton's (already reviewed) `@str` removal (and fixed the problems in a separate commit); the only new work is the trailing commits with my authorship.
Closes#11967
This is has been obsolete for quite a while now (including a release),
so removing the special handling seems fine. (The error message is quite
good still anyway.)
Fixes#9580.
`Times::times` was always a second-class loop because it did not support the `break` and `continue` operations. Its playful appeal was then lost after `do` was disabled for closures. It's time to let this one go.
cc #7621.
See the commit message. I'm not sure if we should merge this now, or wait until we can write `Clone::clone(x)` which will directly solve the above issue with perfect error messages.
This unfortunately changes an error like
error: mismatched types: expected `&&NotClone` but found `&NotClone`
into
error: type `NotClone` does not implement any method in scope named `clone`
I'd forgotten to update them when I changed this a while ago; it now displays error messages linked to the struct/variant field, rather than the `#[deriving(Trait)]` line, for all traits.
This also adds a very large number of autogenerated tests. I can easily remove/tone down that commit if necessary.
This makes error messages about (e.g.) `#[deriving(Clone)] struct Foo {
x: Type }` point at `x: Type` rather than `Clone` in the header (while
still referring to the `#[deriving(Clone)]` in the expansion info).
Now that procedural macros can be implemented outside of the compiler,
it's more important to have a reasonable API to work with. Here are the
basic changes:
* Rename SyntaxExpanderTTTrait to MacroExpander, SyntaxExpanderTT to
BasicMacroExpander, etc. I think "procedural macro" is the right
term for these now, right? The other option would be SynExtExpander
or something like that.
* Stop passing the SyntaxContext to extensions. This was only ever used
by macro_rules, which doesn't even use it anymore. I can't think of
a context in which an external extension would need it, and removal
allows the API to be significantly simpler - no more
SyntaxExpanderTTItemExpanderWithoutContext wrappers to worry about.
Now that procedural macros can be implemented outside of the compiler,
it's more important to have a reasonable API to work with. Here are the
basic changes:
* Rename SyntaxExpanderTTTrait to MacroExpander, SyntaxExpanderTT to
BasicMacroExpander, etc. I think "procedural macro" is the right
term for these now, right? The other option would be SynExtExpander
or something like that.
* Stop passing the SyntaxContext to extensions. This was only ever used
by macro_rules, which doesn't even use it anymore. I can't think of
a context in which an external extension would need it, and removal
allows the API to be significantly simpler - no more
SyntaxExpanderTTItemExpanderWithoutContext wrappers to worry about.
They all have to go into a single module at the moment unfortunately.
Ideally, the logging macros would live in std::logging, condition! would
live in std::condition, format! in std::fmt, etc. However, this
introduces cyclic dependencies between those modules and the macros they
use which the current expansion system can't deal with. We may be able
to get around this by changing the expansion phase to a two-pass system
but that's for a later PR.
Closes#2247
cc #11763
The old method of serializing the AST gives totally bogus spans if the
expansion of an imported macro causes compilation errors. The best
solution seems to be to serialize the actual textual macro definition
and load it the same way the std-macros are. I'm not totally confident
that getting the source from the CodeMap will always do the right thing,
but it seems to work in simple cases.
A mutable and immutable borrow place some restrictions on what you can
with the variable until the borrow ends. This commit attempts to convey
to the user what those restrictions are. Also, if the original borrow is
a mutable borrow, the error message has been changed (more specifically,
i. "cannot borrow `x` as immutable because it is also borrowed as
mutable" and ii. "cannot borrow `x` as mutable more than once" have
been changed to "cannot borrow `x` because it is already borrowed as
mutable").
In addition, this adds a (custom) span note to communicate where the
original borrow ends.
```rust
fn main() {
match true {
true => {
let mut x = 1;
let y = &x;
let z = &mut x;
}
false => ()
}
}
test.rs:6:21: 6:27 error: cannot borrow `x` as mutable because it is already borrowed as immutable
test.rs:6 let z = &mut x;
^~~~~~
test.rs:5:21: 5:23 note: previous borrow of `x` occurs here; the immutable borrow prevents subsequent moves or mutable borrows of `x` until the borrow ends
test.rs:5 let y = &x;
^~
test.rs:7:10: 7:10 note: previous borrow ends here
test.rs:3 true => {
test.rs:4 let mut x = 1;
test.rs:5 let y = &x;
test.rs:6 let z = &mut x;
test.rs:7 }
^
```
```rust
fn foo3(t0: &mut &mut int) {
let t1 = &mut *t0;
let p: &int = &**t0;
}
fn main() {}
test.rs:3:19: 3:24 error: cannot borrow `**t0` because it is already borrowed as mutable
test.rs:3 let p: &int = &**t0;
^~~~~
test.rs:2:14: 2:22 note: previous borrow of `**t0` as mutable occurs here; the mutable borrow prevents subsequent moves, borrows, or modification of `**t0` until the borrow ends
test.rs:2 let t1 = &mut *t0;
^~~~~~~~
test.rs:4:2: 4:2 note: previous borrow ends here
test.rs:1 fn foo3(t0: &mut &mut int) {
test.rs:2 let t1 = &mut *t0;
test.rs:3 let p: &int = &**t0;
test.rs:4 }
^
```
For the "previous borrow ends here" note, if the span is too long (has too many lines), then only the first and last lines are printed, and the middle is replaced with dot dot dot:
```rust
fn foo3(t0: &mut &mut int) {
let t1 = &mut *t0;
let p: &int = &**t0;
}
fn main() {}
test.rs:3:19: 3:24 error: cannot borrow `**t0` because it is already borrowed as mutable
test.rs:3 let p: &int = &**t0;
^~~~~
test.rs:2:14: 2:22 note: previous borrow of `**t0` as mutable occurs here; the mutable borrow prevents subsequent moves, borrows, or modification of `**t0` until the borrow ends
test.rs:2 let t1 = &mut *t0;
^~~~~~~~
test.rs:7:2: 7:2 note: previous borrow ends here
test.rs:1 fn foo3(t0: &mut &mut int) {
...
test.rs:7 }
^
```
(Sidenote: the `span_end_note` currently also has issue #11715)
Renamed the ```invert()``` function in ```iter.rs``` to ```flip()```, from #10632
Also renamed the ```Invert<T>``` type to ```Flip<T>```.
Some related code comments changed. Documentation that I could find has
been updated, and all the instances I could locate where the
function/type were called have been updated as well.
This is my first contribution to Rust! Apologies in advance if I've snarfed the
PR process, I'm not used to rebase.
I initially had issues with the ```codegen``` section of the tests failing, however
the ```make check``` process is not reporting any failures at this time. I think
that was a local env issue more than me facerolling my changes. :)
This patchset consists of three parts:
- rustpkg doesn't guess crate version if it is not given by user.
- `rustpkg::version::Version` is replaced by `Option<~str>`.
It removes some semantic versioning portions which is not currently used.
(cc #8405 and #11396)
`rustpkg::crate_id::CrateId` is also replaced by `syntax::crateid::CrateId`.
- rustpkg now computes hash to find crate, instead of manual filename parse.
cc @metajack
Renamed the invert() function in iter.rs to flip().
Also renamed the Invert<T> type to Flip<T>.
Some related code comments changed. Documentation that I could find has
been updated, and all the instances I could locate where the
function/type were called have been updated as well.
A mutable and immutable borrow place some restrictions on what you can
with the variable until the borrow ends. This commit attempts to convey
to the user what those restrictions are. Also, if the original borrow is
a mutable borrow, the error message has been changed (more specifically,
i. "cannot borrow `x` as immutable because it is also borrowed as
mutable" and ii. "cannot borrow `x` as mutable more than once" have
been changed to "cannot borrow `x` because it is already borrowed as
mutable").
In addition, this adds a (custom) span note to communicate where the
original borrow ends.
The old method of serializing the AST gives totally bogus spans if the
expansion of an imported macro causes compilation errors. The best
solution seems to be to serialize the actual textual macro definition
and load it the same way the std-macros are. I'm not totally confident
that getting the source from the CodeMap will always do the right thing,
but it seems to work in simple cases.
This means that compilation continues for longer, and so we can see more
errors per compile. This is mildly more user-friendly because it stops
users having to run rustc n times to see n macro errors: just run it
once to see all of them.
If the library is in the working directory, its path won't have a "/"
which will cause dlopen to search /usr/lib etc. It turns out that Path
auto-normalizes during joins so Path::new(".").join(path) is actually a
no-op.
NodeIds are sequential integers starting at zero, so we can achieve some
memory savings by just storing the items all in a line in a vector.
The occupancy for typical crates seems to be 75-80%, so we're already
more efficient than a HashMap (maximum occupancy 75%), not even counting
the extra book-keeping that HashMap does.
