Rust wrapper for libctru
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// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
//! Standard library macros
//!
//! This modules contains a set of macros which are exported from the standard
//! library. Each macro is available for use when linking against the standard
//! library.
/// The entry point for panic of Rust threads.
///
/// This allows a program to to terminate immediately and provide feedback
/// to the caller of the program. `panic!` should be used when a program reaches
/// an unrecoverable problem.
///
/// This macro is the perfect way to assert conditions in example code and in
/// tests. `panic!` is closely tied with the `unwrap` method of both [`Option`]
/// and [`Result`][runwrap] enums. Both implementations call `panic!` when they are set
/// to None or Err variants.
///
/// This macro is used to inject panic into a Rust thread, causing the thread to
/// panic entirely. Each thread's panic can be reaped as the `Box<Any>` type,
/// and the single-argument form of the `panic!` macro will be the value which
/// is transmitted.
///
/// [`Result`] enum is often a better solution for recovering from errors than
/// using the `panic!` macro. This macro should be used to avoid proceeding using
/// incorrect values, such as from external sources. Detailed information about
/// error handling is found in the [book].
///
/// The multi-argument form of this macro panics with a string and has the
/// [`format!`] syntax for building a string.
///
/// [runwrap]: ../std/result/enum.Result.html#method.unwrap
/// [`Option`]: ../std/option/enum.Option.html#method.unwrap
/// [`Result`]: ../std/result/enum.Result.html
/// [`format!`]: ../std/macro.format.html
/// [book]: ../book/second-edition/ch09-01-unrecoverable-errors-with-panic.html
///
/// # Current implementation
///
/// If the main thread panics it will terminate all your threads and end your
/// program with code `101`.
///
/// # Examples
///
/// ```should_panic
/// # #![allow(unreachable_code)]
/// panic!();
/// panic!("this is a terrible mistake!");
/// panic!(4); // panic with the value of 4 to be collected elsewhere
/// panic!("this is a {} {message}", "fancy", message = "message");
/// ```
#[macro_export]
#[stable(feature = "rust1", since = "1.0.0")]
#[allow_internal_unstable]
macro_rules! panic {
() => ({
panic!("explicit panic")
});
($msg:expr) => ({
$crate::rt::begin_panic($msg, &(file!(), line!(), __rust_unstable_column!()))
});
($fmt:expr, $($arg:tt)+) => ({
$crate::rt::begin_panic_fmt(&format_args!($fmt, $($arg)+),
&(file!(), line!(), __rust_unstable_column!()))
});
}
/// Macro for printing to the standard output.
///
/// Equivalent to the [`println!`] macro except that a newline is not printed at
/// the end of the message.
///
/// Note that stdout is frequently line-buffered by default so it may be
/// necessary to use [`io::stdout().flush()`][flush] to ensure the output is emitted
/// immediately.
///
/// Use `print!` only for the primary output of your program. Use
/// [`eprint!`] instead to print error and progress messages.
///
/// [`println!`]: ../std/macro.println.html
/// [flush]: ../std/io/trait.Write.html#tymethod.flush
/// [`eprint!`]: ../std/macro.eprint.html
///
/// # Panics
///
/// Panics if writing to `io::stdout()` fails.
///
/// # Examples
///
/// ```
/// use std::io::{self, Write};
///
/// print!("this ");
/// print!("will ");
/// print!("be ");
/// print!("on ");
/// print!("the ");
/// print!("same ");
/// print!("line ");
///
/// io::stdout().flush().unwrap();
///
/// print!("this string has a newline, why not choose println! instead?\n");
///
/// io::stdout().flush().unwrap();
/// ```
#[macro_export]
#[stable(feature = "rust1", since = "1.0.0")]
#[allow_internal_unstable]
macro_rules! print {
($($arg:tt)*) => ($crate::io::_print(format_args!($($arg)*)));
}
/// Macro for printing to the standard output, with a newline.
///
/// On all platforms, the newline is the LINE FEED character (`\n`/`U+000A`) alone
/// (no additional CARRIAGE RETURN (`\r`/`U+000D`).
///
/// Use the [`format!`] syntax to write data to the standard output.
/// See [`std::fmt`] for more information.
///
/// Use `println!` only for the primary output of your program. Use
/// [`eprintln!`] instead to print error and progress messages.
///
/// [`format!`]: ../std/macro.format.html
/// [`std::fmt`]: ../std/fmt/index.html
/// [`eprintln!`]: ../std/macro.eprint.html
/// # Panics
///
/// Panics if writing to `io::stdout` fails.
///
/// # Examples
///
/// ```
/// println!(); // prints just a newline
/// println!("hello there!");
/// println!("format {} arguments", "some");
/// ```
#[macro_export]
#[stable(feature = "rust1", since = "1.0.0")]
macro_rules! println {
() => (print!("\n"));
($fmt:expr) => (print!(concat!($fmt, "\n")));
($fmt:expr, $($arg:tt)*) => (print!(concat!($fmt, "\n"), $($arg)*));
}
/// Macro for printing to the standard error.
///
/// Equivalent to the [`print!`] macro, except that output goes to
/// [`io::stderr`] instead of `io::stdout`. See [`print!`] for
/// example usage.
///
/// Use `eprint!` only for error and progress messages. Use `print!`
/// instead for the primary output of your program.
///
/// [`io::stderr`]: ../std/io/struct.Stderr.html
/// [`print!`]: ../std/macro.print.html
///
/// # Panics
///
/// Panics if writing to `io::stderr` fails.
///
/// # Examples
///
/// ```
/// eprint!("Error: Could not complete task");
/// ```
#[macro_export]
#[stable(feature = "eprint", since = "1.19.0")]
#[allow_internal_unstable]
macro_rules! eprint {
($($arg:tt)*) => ($crate::io::_eprint(format_args!($($arg)*)));
}
/// Macro for printing to the standard error, with a newline.
///
/// Equivalent to the [`println!`] macro, except that output goes to
/// [`io::stderr`] instead of `io::stdout`. See [`println!`] for
/// example usage.
///
/// Use `eprintln!` only for error and progress messages. Use `println!`
/// instead for the primary output of your program.
///
/// [`io::stderr`]: ../std/io/struct.Stderr.html
/// [`println!`]: ../std/macro.println.html
///
/// # Panics
///
/// Panics if writing to `io::stderr` fails.
///
/// # Examples
///
/// ```
/// eprintln!("Error: Could not complete task");
/// ```
#[macro_export]
#[stable(feature = "eprint", since = "1.19.0")]
macro_rules! eprintln {
() => (eprint!("\n"));
($fmt:expr) => (eprint!(concat!($fmt, "\n")));
($fmt:expr, $($arg:tt)*) => (eprint!(concat!($fmt, "\n"), $($arg)*));
}
/// A macro to select an event from a number of receivers.
///
/// This macro is used to wait for the first event to occur on a number of
/// receivers. It places no restrictions on the types of receivers given to
/// this macro, this can be viewed as a heterogeneous select.
///
/// # Examples
///
/// ```
/// #![feature(mpsc_select)]
///
/// use std::thread;
/// use std::sync::mpsc;
///
/// // two placeholder functions for now
/// fn long_running_thread() {}
/// fn calculate_the_answer() -> u32 { 42 }
///
/// let (tx1, rx1) = mpsc::channel();
/// let (tx2, rx2) = mpsc::channel();
///
/// thread::spawn(move|| { long_running_thread(); tx1.send(()).unwrap(); });
/// thread::spawn(move|| { tx2.send(calculate_the_answer()).unwrap(); });
///
/// select! {
/// _ = rx1.recv() => println!("the long running thread finished first"),
/// answer = rx2.recv() => {
/// println!("the answer was: {}", answer.unwrap());
/// }
/// }
/// # drop(rx1.recv());
/// # drop(rx2.recv());
/// ```
///
/// For more information about select, see the `std::sync::mpsc::Select` structure.
#[macro_export]
#[unstable(feature = "mpsc_select", issue = "27800")]
macro_rules! select {
(
$($name:pat = $rx:ident.$meth:ident() => $code:expr),+
) => ({
use $crate::sync::mpsc::Select;
let sel = Select::new();
$( let mut $rx = sel.handle(&$rx); )+
unsafe {
$( $rx.add(); )+
}
let ret = sel.wait();
$( if ret == $rx.id() { let $name = $rx.$meth(); $code } else )+
{ unreachable!() }
})
}
#[cfg(test)]
macro_rules! assert_approx_eq {
($a:expr, $b:expr) => ({
let (a, b) = (&$a, &$b);
assert!((*a - *b).abs() < 1.0e-6,
"{} is not approximately equal to {}", *a, *b);
})
}
/// Built-in macros to the compiler itself.
///
/// These macros do not have any corresponding definition with a `macro_rules!`
/// macro, but are documented here. Their implementations can be found hardcoded
/// into libsyntax itself.
#[cfg(dox)]
pub mod builtin {
/// Unconditionally causes compilation to fail with the given error message when encountered.
///
/// This macro should be used when a crate uses a conditional compilation strategy to provide
/// better error messages for erroneous conditions.
///
/// # Examples
///
/// Two such examples are macros and `#[cfg]` environments.
///
/// Emit better compiler error if a macro is passed invalid values.
///
/// ```compile_fail
/// macro_rules! give_me_foo_or_bar {
/// (foo) => {};
/// (bar) => {};
/// ($x:ident) => {
/// compile_error!("This macro only accepts `foo` or `bar`");
/// }
/// }
///
/// give_me_foo_or_bar!(neither);
/// // ^ will fail at compile time with message "This macro only accepts `foo` or `bar`"
/// ```
///
/// Emit compiler error if one of a number of features isn't available.
///
/// ```compile_fail
/// #[cfg(not(any(feature = "foo", feature = "bar")))]
/// compile_error!("Either feature \"foo\" or \"bar\" must be enabled for this crate.")
/// ```
#[stable(feature = "compile_error_macro", since = "1.20.0")]
#[macro_export]
macro_rules! compile_error { ($msg:expr) => ({ /* compiler built-in */ }) }
/// The core macro for formatted string creation & output.
///
/// This macro functions by taking a formatting string literal containing
/// `{}` for each additional argument passed. `format_args!` prepares the
/// additional parameters to ensure the output can be interpreted as a string
/// and canonicalizes the arguments into a single type. Any value that implements
/// the [`Display`] trait can be passed to `format_args!`, as can any
/// [`Debug`] implementation be passed to a `{:?}` within the formatting string.
///
/// This macro produces a value of type [`fmt::Arguments`]. This value can be
/// passed to the macros within [`std::fmt`] for performing useful redirection.
/// All other formatting macros ([`format!`], [`write!`], [`println!`], etc) are
/// proxied through this one. `format_args!`, unlike its derived macros, avoids
/// heap allocations.
///
/// For more information, see the documentation in [`std::fmt`].
///
/// [`Display`]: ../std/fmt/trait.Display.html
/// [`Debug`]: ../std/fmt/trait.Debug.html
/// [`fmt::Arguments`]: ../std/fmt/struct.Arguments.html
/// [`std::fmt`]: ../std/fmt/index.html
/// [`format!`]: ../std/macro.format.html
/// [`write!`]: ../std/macro.write.html
/// [`println!`]: ../std/macro.println.html
///
/// # Examples
///
/// ```
/// use std::fmt;
///
/// let s = fmt::format(format_args!("hello {}", "world"));
/// assert_eq!(s, format!("hello {}", "world"));
///
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
#[macro_export]
macro_rules! format_args {
($fmt:expr) => ({ /* compiler built-in */ });
($fmt:expr, $($args:tt)*) => ({ /* compiler built-in */ });
}
/// Inspect an environment variable at compile time.
///
/// This macro will expand to the value of the named environment variable at
/// compile time, yielding an expression of type `&'static str`.
///
/// If the environment variable is not defined, then a compilation error
/// will be emitted. To not emit a compile error, use the [`option_env!`]
/// macro instead.
///
/// [`option_env!`]: ../std/macro.option_env.html
///
/// # Examples
///
/// ```
/// let path: &'static str = env!("PATH");
/// println!("the $PATH variable at the time of compiling was: {}", path);
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
#[macro_export]
macro_rules! env {
($name:expr) => ({ /* compiler built-in */ });
($name:expr,) => ({ /* compiler built-in */ });
}
/// Optionally inspect an environment variable at compile time.
///
/// If the named environment variable is present at compile time, this will
/// expand into an expression of type `Option<&'static str>` whose value is
/// `Some` of the value of the environment variable. If the environment
/// variable is not present, then this will expand to `None`. See
/// [`Option<T>`][option] for more information on this type.
///
/// A compile time error is never emitted when using this macro regardless
/// of whether the environment variable is present or not.
///
/// [option]: ../std/option/enum.Option.html
///
/// # Examples
///
/// ```
/// let key: Option<&'static str> = option_env!("SECRET_KEY");
/// println!("the secret key might be: {:?}", key);
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
#[macro_export]
macro_rules! option_env { ($name:expr) => ({ /* compiler built-in */ }) }
/// Concatenate identifiers into one identifier.
///
/// This macro takes any number of comma-separated identifiers, and
/// concatenates them all into one, yielding an expression which is a new
/// identifier. Note that hygiene makes it such that this macro cannot
/// capture local variables. Also, as a general rule, macros are only
/// allowed in item, statement or expression position. That means while
/// you may use this macro for referring to existing variables, functions or
/// modules etc, you cannot define a new one with it.
///
/// # Examples
///
/// ```
/// #![feature(concat_idents)]
///
/// # fn main() {
/// fn foobar() -> u32 { 23 }
///
/// let f = concat_idents!(foo, bar);
/// println!("{}", f());
///
/// // fn concat_idents!(new, fun, name) { } // not usable in this way!
/// # }
/// ```
#[unstable(feature = "concat_idents_macro", issue = "29599")]
#[macro_export]
macro_rules! concat_idents {
($($e:ident),*) => ({ /* compiler built-in */ });
($($e:ident,)*) => ({ /* compiler built-in */ });
}
/// Concatenates literals into a static string slice.
///
/// This macro takes any number of comma-separated literals, yielding an
/// expression of type `&'static str` which represents all of the literals
/// concatenated left-to-right.
///
/// Integer and floating point literals are stringified in order to be
/// concatenated.
///
/// # Examples
///
/// ```
/// let s = concat!("test", 10, 'b', true);
/// assert_eq!(s, "test10btrue");
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
#[macro_export]
macro_rules! concat {
($($e:expr),*) => ({ /* compiler built-in */ });
($($e:expr,)*) => ({ /* compiler built-in */ });
}
/// A macro which expands to the line number on which it was invoked.
///
/// With [`column!`] and [`file!`], these macros provide debugging information for
/// developers about the location within the source.
///
/// The expanded expression has type `u32` and is 1-based, so the first line
/// in each file evaluates to 1, the second to 2, etc. This is consistent
/// with error messages by common compilers or popular editors.
/// The returned line is not the invocation of the `line!` macro itself,
/// but rather the first macro invocation leading up to the invocation
/// of the `line!` macro.
///
/// [`column!`]: macro.column.html
/// [`file!`]: macro.file.html
///
/// # Examples
///
/// ```
/// let current_line = line!();
/// println!("defined on line: {}", current_line);
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
#[macro_export]
macro_rules! line { () => ({ /* compiler built-in */ }) }
/// A macro which expands to the column number on which it was invoked.
///
/// With [`line!`] and [`file!`], these macros provide debugging information for
/// developers about the location within the source.
///
/// The expanded expression has type `u32` and is 1-based, so the first column
/// in each line evaluates to 1, the second to 2, etc. This is consistent
/// with error messages by common compilers or popular editors.
/// The returned column is not the invocation of the `column!` macro itself,
/// but rather the first macro invocation leading up to the invocation
/// of the `column!` macro.
///
/// [`line!`]: macro.line.html
/// [`file!`]: macro.file.html
///
/// # Examples
///
/// ```
/// let current_col = column!();
/// println!("defined on column: {}", current_col);
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
#[macro_export]
macro_rules! column { () => ({ /* compiler built-in */ }) }
/// A macro which expands to the file name from which it was invoked.
///
/// With [`line!`] and [`column!`], these macros provide debugging information for
/// developers about the location within the source.
///
///
/// The expanded expression has type `&'static str`, and the returned file
/// is not the invocation of the `file!` macro itself, but rather the
/// first macro invocation leading up to the invocation of the `file!`
/// macro.
///
/// [`line!`]: macro.line.html
/// [`column!`]: macro.column.html
///
/// # Examples
///
/// ```
/// let this_file = file!();
/// println!("defined in file: {}", this_file);
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
#[macro_export]
macro_rules! file { () => ({ /* compiler built-in */ }) }
/// A macro which stringifies its arguments.
///
/// This macro will yield an expression of type `&'static str` which is the
/// stringification of all the tokens passed to the macro. No restrictions
/// are placed on the syntax of the macro invocation itself.
///
/// Note that the expanded results of the input tokens may change in the
/// future. You should be careful if you rely on the output.
///
/// # Examples
///
/// ```
/// let one_plus_one = stringify!(1 + 1);
/// assert_eq!(one_plus_one, "1 + 1");
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
#[macro_export]
macro_rules! stringify { ($($t:tt)*) => ({ /* compiler built-in */ }) }
/// Includes a utf8-encoded file as a string.
///
/// The file is located relative to the current file. (similarly to how
/// modules are found)
///
/// This macro will yield an expression of type `&'static str` which is the
/// contents of the file.
///
/// # Examples
///
/// Assume there are two files in the same directory with the following
/// contents:
///
/// File 'spanish.in':
///
/// ```text
/// adiós
/// ```
///
/// File 'main.rs':
///
/// ```ignore (cannot-doctest-external-file-dependency)
/// fn main() {
/// let my_str = include_str!("spanish.in");
/// assert_eq!(my_str, "adiós\n");
/// print!("{}", my_str);
/// }
/// ```
///
/// Compiling 'main.rs' and running the resulting binary will print "adiós".
#[stable(feature = "rust1", since = "1.0.0")]
#[macro_export]
macro_rules! include_str { ($file:expr) => ({ /* compiler built-in */ }) }
/// Includes a file as a reference to a byte array.
///
/// The file is located relative to the current file. (similarly to how
/// modules are found)
///
/// This macro will yield an expression of type `&'static [u8; N]` which is
/// the contents of the file.
///
/// # Examples
///
/// Assume there are two files in the same directory with the following
/// contents:
///
/// File 'spanish.in':
///
/// ```text
/// adiós
/// ```
///
/// File 'main.rs':
///
/// ```ignore (cannot-doctest-external-file-dependency)
/// fn main() {
/// let bytes = include_bytes!("spanish.in");
/// assert_eq!(bytes, b"adi\xc3\xb3s\n");
/// print!("{}", String::from_utf8_lossy(bytes));
/// }
/// ```
///
/// Compiling 'main.rs' and running the resulting binary will print "adiós".
#[stable(feature = "rust1", since = "1.0.0")]
#[macro_export]
macro_rules! include_bytes { ($file:expr) => ({ /* compiler built-in */ }) }
/// Expands to a string that represents the current module path.
///
/// The current module path can be thought of as the hierarchy of modules
/// leading back up to the crate root. The first component of the path
/// returned is the name of the crate currently being compiled.
///
/// # Examples
///
/// ```
/// mod test {
/// pub fn foo() {
/// assert!(module_path!().ends_with("test"));
/// }
/// }
///
/// test::foo();
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
#[macro_export]
macro_rules! module_path { () => ({ /* compiler built-in */ }) }
/// Boolean evaluation of configuration flags, at compile-time.
///
/// In addition to the `#[cfg]` attribute, this macro is provided to allow
/// boolean expression evaluation of configuration flags. This frequently
/// leads to less duplicated code.
///
/// The syntax given to this macro is the same syntax as [the `cfg`
/// attribute](../book/first-edition/conditional-compilation.html).
///
/// # Examples
///
/// ```
/// let my_directory = if cfg!(windows) {
/// "windows-specific-directory"
/// } else {
/// "unix-directory"
/// };
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
#[macro_export]
macro_rules! cfg { ($($cfg:tt)*) => ({ /* compiler built-in */ }) }
/// Parse a file as an expression or an item according to the context.
///
/// The file is located relative to the current file (similarly to how
/// modules are found).
///
/// Using this macro is often a bad idea, because if the file is
/// parsed as an expression, it is going to be placed in the
/// surrounding code unhygienically. This could result in variables
/// or functions being different from what the file expected if
/// there are variables or functions that have the same name in
/// the current file.
///
/// # Examples
///
/// Assume there are two files in the same directory with the following
/// contents:
///
/// File 'monkeys.in':
///
/// ```ignore (only-for-syntax-highlight)
/// ['🙈', '🙊', '🙉']
/// .iter()
/// .cycle()
/// .take(6)
/// .collect::<String>()
/// ```
///
/// File 'main.rs':
///
/// ```ignore (cannot-doctest-external-file-dependency)
/// fn main() {
/// let my_string = include!("monkeys.in");
/// assert_eq!("🙈🙊🙉🙈🙊🙉", my_string);
/// println!("{}", my_string);
/// }
/// ```
///
/// Compiling 'main.rs' and running the resulting binary will print
/// "🙈🙊🙉🙈🙊🙉".
#[stable(feature = "rust1", since = "1.0.0")]
#[macro_export]
macro_rules! include { ($file:expr) => ({ /* compiler built-in */ }) }
}
/// A macro for defining #[cfg] if-else statements.
///
/// This is similar to the `if/elif` C preprocessor macro by allowing definition
/// of a cascade of `#[cfg]` cases, emitting the implementation which matches
/// first.
///
/// This allows you to conveniently provide a long list #[cfg]'d blocks of code
/// without having to rewrite each clause multiple times.
macro_rules! cfg_if {
($(
if #[cfg($($meta:meta),*)] { $($it:item)* }
) else * else {
$($it2:item)*
}) => {
__cfg_if_items! {
() ;
$( ( ($($meta),*) ($($it)*) ), )*
( () ($($it2)*) ),
}
}
}
macro_rules! __cfg_if_items {
(($($not:meta,)*) ; ) => {};
(($($not:meta,)*) ; ( ($($m:meta),*) ($($it:item)*) ), $($rest:tt)*) => {
__cfg_if_apply! { cfg(all(not(any($($not),*)), $($m,)*)), $($it)* }
__cfg_if_items! { ($($not,)* $($m,)*) ; $($rest)* }
}
}
macro_rules! __cfg_if_apply {
($m:meta, $($it:item)*) => {
$(#[$m] $it)*
}
}