This commit moves reflection (as well as the {:?} format modifier) to a new
libdebug crate, all of which is marked experimental.
This is a breaking change because it now requires the debug crate to be
explicitly linked if the :? format qualifier is used. This means that any code
using this feature will have to add `extern crate debug;` to the top of the
crate. Any code relying on reflection will also need to do this.
Closes#12019
[breaking-change]
This code does not belong in libstd, and rather belongs in a dedicated crate. In
the future, the syntax::ext::format module should move to the fmt_macros crate
(hence the name of the crate), but for now the fmt_macros crate will only
contain the format string parser.
The entire fmt_macros crate is marked #[experimental] because it is not meant
for general consumption, only the format!() interface is officially supported,
not the internals.
This is a breaking change for anyone using the internals of std::fmt::parse.
Some of the flags have moved to std::fmt::rt, while the actual parsing support
has all moved to the fmt_macros library.
[breaking-change]
This is a stand-in until we have a saner `~[T]` type (i.e. a proper
owned slice). It's a library version of what `~[T]` will be, i.e. an
owned pointer and a length.
This commit moves all logging out of the standard library into an external
crate. This crate is the new crate which is responsible for all logging macros
and logging implementation. A few reasons for this change are:
* The crate map has always been a bit of a code smell among rust programs. It
has difficulty being loaded on almost all platforms, and it's used almost
exclusively for logging and only logging. Removing the crate map is one of the
end goals of this movement.
* The compiler has a fair bit of special support for logging. It has the
__log_level() expression as well as generating a global word per module
specifying the log level. This is unfairly favoring the built-in logging
system, and is much better done purely in libraries instead of the compiler
itself.
* Initialization of logging is much easier to do if there is no reliance on a
magical crate map being available to set module log levels.
* If the logging library can be written outside of the standard library, there's
no reason that it shouldn't be. It's likely that we're not going to build the
highest quality logging library of all time, so third-party libraries should
be able to provide just as high-quality logging systems as the default one
provided in the rust distribution.
With a migration such as this, the change does not come for free. There are some
subtle changes in the behavior of liblog vs the previous logging macros:
* The core change of this migration is that there is no longer a physical
log-level per module. This concept is still emulated (it is quite useful), but
there is now only a global log level, not a local one. This global log level
is a reflection of the maximum of all log levels specified. The previously
generated logging code looked like:
if specified_level <= __module_log_level() {
println!(...)
}
The newly generated code looks like:
if specified_level <= ::log::LOG_LEVEL {
if ::log::module_enabled(module_path!()) {
println!(...)
}
}
Notably, the first layer of checking is still intended to be "super fast" in
that it's just a load of a global word and a compare. The second layer of
checking is executed to determine if the current module does indeed have
logging turned on.
This means that if any module has a debug log level turned on, all modules
with debug log levels get a little bit slower (they all do more expensive
dynamic checks to determine if they're turned on or not).
Semantically, this migration brings no change in this respect, but
runtime-wise, this will have a perf impact on some code.
* A `RUST_LOG=::help` directive will no longer print out a list of all modules
that can be logged. This is because the crate map will no longer specify the
log levels of all modules, so the list of modules is not known. Additionally,
warnings can no longer be provided if a malformed logging directive was
supplied.
The new "hello world" for logging looks like:
#[phase(syntax, link)]
extern crate log;
fn main() {
debug!("Hello, world!");
}
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.
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.
- `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
Understand 'pkgid' in stage0. As a bonus, the snapshot now contains now metadata
(now that those changes have landed), and the snapshot download is half as large
as it used to be!
This replaces the link meta attributes with a pkgid attribute and uses a hash
of this as the crate hash. This makes the crate hash computable by things
other than the Rust compiler. It also switches the hash function ot SHA1 since
that is much more likely to be available in shell, Python, etc than SipHash.
Fixes#10188, #8523.
In order to keep up to date with changes to the libraries that `llvm-config`
spits out, the dependencies to the LLVM are a dynamically generated rust file.
This file is now automatically updated whenever LLVM is updated to get kept
up-to-date.
At the same time, this cleans out some old cruft which isn't necessary in the
makefiles in terms of dependencies.
Closes#10745Closes#10744
Keegan McAllister