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 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.
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.
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.
Major changes:
- Define temporary scopes in a syntax-based way that basically defaults
to the innermost statement or conditional block, except for in
a `let` initializer, where we default to the innermost block. Rules
are documented in the code, but not in the manual (yet).
See new test run-pass/cleanup-value-scopes.rs for examples.
- Refactors Datum to better define cleanup roles.
- Refactor cleanup scopes to not be tied to basic blocks, permitting
us to have a very large number of scopes (one per AST node).
- Introduce nascent documentation in trans/doc.rs covering datums and
cleanup in a more comprehensive way.
r? @pcwalton
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.
The `print!` and `println!` macros are now the preferred method of printing, and so there is no reason to export the `stdio` functions in the prelude. The functions have also been replaced by their macro counterparts in the tutorial and other documentation so that newcomers don't get confused about what they should be using.
I'd really like to be able to do something like
```rust
struct MapChain<'next, K, V> {
info: BlockInfo,
map: HashMap<K, V>,
next: Option<&'next mut MapChain<'next, K, V>
}
```
but I can't get the lifetimes to work out.
I'd really like to be able to do something like
struct MapChain<'next, K, V> {
info: BlockInfo,
map: HashMap<K, V>,
next: Option<&'next mut MapChain<'next, K, V>
}
but I can't get the lifetimes to work out.
This extracts everything related to green scheduling from libstd and introduces
a new libgreen crate. This mostly involves deleting most of std::rt and moving
it to libgreen.
Along with the movement of code, this commit rearchitects many functions in the
scheduler in order to adapt to the fact that Local::take now *only* works on a
Task, not a scheduler. This mostly just involved threading the current green
task through in a few locations, but there were one or two spots where things
got hairy.
There are a few repercussions of this commit:
* tube/rc have been removed (the runtime implementation of rc)
* There is no longer a "single threaded" spawning mode for tasks. This is now
encompassed by 1:1 scheduling + communication. Convenience methods have been
introduced that are specific to libgreen to assist in the spawning of pools of
schedulers.
These two attributes are no longer useful now that Rust has decided to leave
segmented stacks behind. It is assumed that the rust task's stack is always
large enough to make an FFI call (due to the stack being very large).
There's always the case of stack overflow, however, to consider. This does not
change the behavior of stack overflow in Rust. This is still normally triggered
by the __morestack function and aborts the whole process.
C stack overflow will continue to corrupt the stack, however (as it did before
this commit as well). The future improvement of a guard page at the end of every
rust stack is still unimplemented and is intended to be the mechanism through
which we attempt to detect C stack overflow.
Closes#8822Closes#10155
This extension can be used to concatenate string literals at compile time. C has
this useful ability when placing string literals lexically next to one another,
but this needs to be handled at the syntax extension level to recursively expand
macros.
The major use case for this is something like:
macro_rules! mylog( ($fmt:expr $($arg:tt)*) => {
error2!(concat!(file!(), ":", line!(), " - ", $fmt) $($arg)*);
})
Where the mylog macro will automatically prepend the filename/line number to the
beginning of every log message.
- `begin_unwind` is now generic over any `T: Any + Send`.
- Every value you fail with gets boxed as an `~Any`.
- Because of implementation details, `&'static str` and `~str` are still
handled specially behind the scenes.
- Changed the big macro source string in libsyntax to a raw string
literal, and enabled doc comments there.
This commit fixes all of the fallout of the previous commit which is an attempt
to refine privacy. There were a few unfortunate leaks which now must be plugged,
and the most horrible one is the current `shouldnt_be_public` module now inside
`std::rt`. I think that this either needs a slight reorganization of the
runtime, or otherwise it needs to just wait for the external users of these
modules to get replaced with their `rt` implementations.
Other fixes involve making things pub which should be pub, and otherwise
updating error messages that now reference privacy instead of referencing an
"unresolved name" (yay!).
We're not outright removing fmt! just yet, but this prevents it from leaking
into the compiler further (it's still turned on by default for all other code).
This lifts various restrictions on the runtime, for example the character limit
when logging a message. Right now the old debug!-style macros still involve
allocating (because they use fmt! syntax), but the new debug2! macros don't
involve allocating at all (unless the formatter for a type requires allocation.
This lifts various restrictions on the runtime, for example the character limit
when logging a message. Right now the old debug!-style macros still involve
allocating (because they use fmt! syntax), but the new debug2! macros don't
involve allocating at all (unless the formatter for a type requires allocation.
Many people will be very confused that their debug! statements aren't working
when they first use rust only to learn that they should have been building with
`--cfg debug` the entire time. This inverts the meaning of the flag to instead
of enabling debug statements, now it disables debug statements.
This way the default behavior is a bit more reasonable, and requires less
end-user configuration. Furthermore, this turns on debug by default when
building the rustc compiler.
This is my first contribution, so please point out anything that I may have missed.
I consulted IRC and settled on `match () { ... }` for most of the replacements.
The same fix as before is still relevant, I just forgot to update the
expand_stmt macro expansion site. The tests for format!() suffice as tests for
this change.
This renames the syntax-extension file to format from ifmt, and it also reduces
the amount of complexity inside by defining all other macros in terms of
format_args!
has a unique id. Fixes numerous bugs in macro expansion and deriving. Add two
representative tests.
Fixes#7971Fixes#6304Fixes#8367Fixes#8754Fixes#8852Fixes#2543Fixes#7654
Also redefine all of the standard logging macros to use more rust code instead
of custom LLVM translation code. This makes them a bit easier to understand, but
also more flexibile for future types of logging.
Additionally, this commit removes the LogType language item in preparation for
changing how logging is performed.
This is actually almost a problem, because those were my poster-child
macros for "here's how to implement a capturing macro." Following this
change, there will be no macros that use capturing; this will probably
make life unpleasant for the first person that wants to implement a
capturing macro. I should probably create a dummy_capturing macro,
just to show how it works.
Also redefine all of the standard logging macros to use more rust code instead
of custom LLVM translation code. This makes them a bit easier to understand, but
also more flexibile for future types of logging.
Additionally, this commit removes the LogType language item in preparation for
changing how logging is performed.
Rationale: having a function which fails means that the location of
failure which is output is that of the unreachable() function, rather
than the caller.
This is part of #8991 but is not all of it; current usage of
``std::util::unreachable()`` must remain so for the moment, until a new
snapshot is made; then I will remove that function entirely in favour of
using this macro.
