rust/src/libstd/rt/logging.rs, branch try

log: Introduce liblog, the old std::logging

2014-03-16T05:26:36+00:00

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!"); }

std: Remove lots of allocations from log settings

2014-02-28T20:24:50+00:00

Most of these are unnecessary because we're only looking at static strings. This also moves to Vec in a few places instead of ~[T]. This didn't end up getting much of a code size win (update_log_settings is the third largest function in the executables I'm looking at), but this seems like a generally nice improvement regardless.

Fixup the rest of the tests in the compiler

2014-01-08T07:51:38+00:00

std: Fill in all missing imports

2014-01-08T07:51:38+00:00

Fallout from the previous commits

Support arbitrary stdout/stderr/logger handles

2014-01-06T21:19:53+00:00

This will allow capturing of common things like logging messages, stdout prints (using stdio println), and failure messages (printed to stderr). Any new prints added to libstd should be funneled through these task handles to allow capture as well. Additionally, this commit redirects logging back through a `Logger` trait so the log level can be usefully consumed by an arbitrary logger. This commit also introduces methods to set the task-local stdout handles: * std::io::stdio::set_stdout * std::io::stdio::set_stderr * std::io::logging::set_logger These methods all return the previous logger just in case it needs to be used for inspection. I plan on using this infrastructure for extra::test soon, but we don't quite have the primitives that I'd like to use for it, so it doesn't migrate extra::test at this time. Closes #6369

std: print RUST_LOG=::help in sorted order.

2013-12-31T12:47:15+00:00

Fixes #8949.

Removed useless cmp::{min, max} reexports from the integer modules

2013-11-29T19:19:22+00:00

libstd: Remove all non-`proc` uses of `do` from libstd

2013-11-26T16:23:57+00:00

Removed unneccessary `_iter` suffixes from various APIs

2013-11-26T09:02:26+00:00

Move std::rt::io to std::io

2013-11-12T04:44:07+00:00