rust/tests/ui/macros/conditional-debug-macro-on.rs

// run-pass
pub fn main() {
    // exits early if println! evaluates its arguments, otherwise it
    // will hit the panic.
    println!("{:?}", { if true { return; } });

    panic!();
}
Add `// run-pass` annotations to all the tests under `ui/run-pass/`. (I may have accidentally added it to some auxilliary crates as well; my emacs-macro-based methodology was pretty crude.) 2018-08-30 07:18:55 -05:00			`// run-pass`
test: Make all the run-pass tests use `pub fn main` 2014-01-03 17:30:54 -06:00			`pub fn main() {`
log: Introduce liblog, the old std::logging 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!"); } 2014-03-09 00:11:44 -06:00			`// exits early if println! evaluates its arguments, otherwise it`
Rename fail! to panic! https://github.com/rust-lang/rfcs/pull/221 The current terminology of "task failure" often causes problems when writing or speaking about code. You often want to talk about the possibility of an operation that returns a Result "failing", but cannot because of the ambiguity with task failure. Instead, you have to speak of "the failing case" or "when the operation does not succeed" or other circumlocutions. Likewise, we use a "Failure" header in rustdoc to describe when operations may fail the task, but it would often be helpful to separate out a section describing the "Err-producing" case. We have been steadily moving away from task failure and toward Result as an error-handling mechanism, so we should optimize our terminology accordingly: Result-producing functions should be easy to describe. To update your code, rename any call to `fail!` to `panic!` instead. Assuming you have not created your own macro named `panic!`, this will work on UNIX based systems: grep -lZR 'fail!' . \| xargs -0 -l sed -i -e 's/fail!/panic!/g' You can of course also do this by hand. [breaking-change] 2014-10-09 14:17:22 -05:00			`// will hit the panic.`
core: split into fmt::Show and fmt::String fmt::Show is for debugging, and can and should be implemented for all public types. This trait is used with `{:?}` syntax. There still exists #[derive(Show)]. fmt::String is for types that faithfully be represented as a String. Because of this, there is no way to derive fmt::String, all implementations must be purposeful. It is used by the default format syntax, `{}`. This will break most instances of `{}`, since that now requires the type to impl fmt::String. In most cases, replacing `{}` with `{:?}` is the correct fix. Types that were being printed specifically for users should receive a fmt::String implementation to fix this. Part of #20013 [breaking-change] 2014-12-20 02:09:35 -06:00			`println!("{:?}", { if true { return; } });`
syntax: make a macros-injection pass; conditionally define debug! to a noop based on cfg(debug). Macros can be conditionally defined because stripping occurs before macro expansion, but, the built-in macros were only added as part of the actual expansion process and so couldn't be stripped to have definitions conditional on cfg flags. debug! is defined conditionally in terms of the debug config, expanding to nothing unless the --cfg debug flag is passed (to be precise it expands to `if false { normal_debug!(...) }` so that they are still type checked, and to avoid unused variable lints). 2013-07-16 00:05:50 -05:00
Rename fail! to panic! https://github.com/rust-lang/rfcs/pull/221 The current terminology of "task failure" often causes problems when writing or speaking about code. You often want to talk about the possibility of an operation that returns a Result "failing", but cannot because of the ambiguity with task failure. Instead, you have to speak of "the failing case" or "when the operation does not succeed" or other circumlocutions. Likewise, we use a "Failure" header in rustdoc to describe when operations may fail the task, but it would often be helpful to separate out a section describing the "Err-producing" case. We have been steadily moving away from task failure and toward Result as an error-handling mechanism, so we should optimize our terminology accordingly: Result-producing functions should be easy to describe. To update your code, rename any call to `fail!` to `panic!` instead. Assuming you have not created your own macro named `panic!`, this will work on UNIX based systems: grep -lZR 'fail!' . \| xargs -0 -l sed -i -e 's/fail!/panic!/g' You can of course also do this by hand. [breaking-change] 2014-10-09 14:17:22 -05:00			`panic!();`
Invert --cfg debug to --cfg ndebug 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. 2013-09-17 23:02:11 -05:00			`}`