rustdoc: Show macros in documentation

Any macro tagged with #[macro_export] will be showed in the documentation for
that module. This also documents all the existing macros inside of std::macros.

Closes #3163
cc #5605
Closes #9954

src/librustdoc/clean.rs

@@ -181,6 +181,7 @@ pub enum ItemEnum {
     VariantItem(Variant),
     ForeignFunctionItem(Function),
     ForeignStaticItem(Static),
+    MacroItem(Macro),
 }
 
 #[deriving(Clone, Encodable, Decodable)]
@@ -206,7 +207,8 @@ impl Clean<Item> for doctree::Module {
                        self.fns.clean(), self.foreigns.clean().concat_vec(),
                        self.mods.clean(), self.typedefs.clean(),
                        self.statics.clean(), self.traits.clean(),
-                       self.impls.clean(), self.view_items.clean()].concat_vec()
+                       self.impls.clean(), self.view_items.clean(),
+                       self.macros.clean()].concat_vec()
             })
         }
     }
@@ -1263,3 +1265,23 @@ fn resolve_def(id: ast::NodeId) -> Option<ast::DefId> {
         None => None
     }
 }
+
+#[deriving(Clone, Encodable, Decodable)]
+pub struct Macro {
+    source: ~str,
+}
+
+impl Clean<Item> for doctree::Macro {
+    fn clean(&self) -> Item {
+        Item {
+            name: Some(self.name.clean()),
+            attrs: self.attrs.clean(),
+            source: self.where.clean(),
+            visibility: ast::Public.clean(),
+            id: self.id,
+            inner: MacroItem(Macro {
+                source: self.where.to_src(),
+            }),
+        }
+    }
+}

src/librustdoc/doctree.rs

@@ -32,6 +32,7 @@ pub struct Module {
     impls: ~[Impl],
     foreigns: ~[ast::ForeignMod],
     view_items: ~[ast::ViewItem],
+    macros: ~[Macro],
 }
 
 impl Module {
@@ -52,6 +53,7 @@ impl Module {
             impls      : ~[],
             view_items : ~[],
             foreigns   : ~[],
+            macros     : ~[],
         }
     }
 }
@@ -157,6 +159,13 @@ pub struct Impl {
     id: ast::NodeId,
 }
 
+pub struct Macro {
+    name: Ident,
+    id: ast::NodeId,
+    attrs: ~[ast::Attribute],
+    where: Span,
+}
+
 pub fn struct_type_from_def(sd: &ast::StructDef) -> StructType {
     if sd.ctor_id.is_some() {
         // We are in a tuple-struct

src/librustdoc/html/render.rs

@@ -798,6 +798,7 @@ fn shortty(item: &clean::Item) -> &'static str {
         clean::VariantItem(..)         => "variant",
         clean::ForeignFunctionItem(..) => "ffi",
         clean::ForeignStaticItem(..)   => "ffs",
+        clean::MacroItem(..)           => "macro",
     }
 }
 
@@ -876,6 +877,7 @@ impl<'a> fmt::Show for Item<'a> {
             clean::StructItem(ref s) => item_struct(fmt.buf, self.item, s),
             clean::EnumItem(ref e) => item_enum(fmt.buf, self.item, e),
             clean::TypedefItem(ref t) => item_typedef(fmt.buf, self.item, t),
+            clean::MacroItem(ref m) => item_macro(fmt.buf, self.item, m),
             _ => Ok(())
         }
     }
@@ -944,6 +946,8 @@ fn item_module(w: &mut Writer, cx: &Context,
             (_, &clean::ViewItemItem(..)) => Greater,
             (&clean::ModuleItem(..), _) => Less,
             (_, &clean::ModuleItem(..)) => Greater,
+            (&clean::MacroItem(..), _) => Less,
+            (_, &clean::MacroItem(..)) => Greater,
             (&clean::StructItem(..), _) => Less,
             (_, &clean::StructItem(..)) => Greater,
             (&clean::EnumItem(..), _) => Less,
@@ -994,6 +998,7 @@ fn item_module(w: &mut Writer, cx: &Context,
                 clean::VariantItem(..)         => "Variants",
                 clean::ForeignFunctionItem(..) => "Foreign Functions",
                 clean::ForeignStaticItem(..)   => "Foreign Statics",
+                clean::MacroItem(..)           => "Macros",
             }));
         }
 
@@ -1616,3 +1621,9 @@ impl<'a> fmt::Show for Source<'a> {
         Ok(())
     }
 }
+
+fn item_macro(w: &mut Writer, it: &clean::Item,
+              t: &clean::Macro) -> fmt::Result {
+    if_ok!(write!(w, "<pre class='macro'>{}</pre>", t.source));
+    document(w, it)
+}

src/librustdoc/passes.rs

@@ -150,8 +150,8 @@ impl<'a> fold::DocFolder for Stripper<'a> {
             }
             clean::ImplItem(..) => {}
 
-            // tymethods have no control over privacy
-            clean::TyMethodItem(..) => {}
+            // tymethods/macros have no control over privacy
+            clean::MacroItem(..) | clean::TyMethodItem(..) => {}
         }
 
         let fastreturn = match i.inner {

src/librustdoc/visit_ast.rs

@@ -280,7 +280,14 @@ impl<'a> RustdocVisitor<'a> {
             ast::ItemForeignMod(ref fm) => {
                 om.foreigns.push(fm.clone());
             }
-            _ => (),
+            ast::ItemMac(ref _m) => {
+                om.macros.push(Macro {
+                    id: item.id,
+                    attrs: item.attrs.clone(),
+                    name: item.ident,
+                    where: item.span,
+                })
+            }
         }
     }
 }

src/libstd/lib.rs

@@ -77,7 +77,7 @@
 #[cfg(test)] pub use ops = realstd::ops;
 #[cfg(test)] pub use cmp = realstd::cmp;
 
-mod macros;
+pub mod macros;
 
 mod rtdeps;
 

src/libstd/macros.rs

@@ -7,8 +7,29 @@
 // <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.
+
 #[macro_escape];
 
+/// The standard logging macro
+///
+/// This macro will generically log over a provided level (of type u32) with a
+/// format!-based argument list. See documentation in `std::fmt` for details on
+/// how to use the syntax, and documentation in `std::logging` for info about
+/// logging macros.
+///
+/// # Example
+///
+/// ```
+/// log!(::std::logging::DEBUG, "this is a debug message");
+/// log!(::std::logging::WARN, "this is a warning {}", "message");
+/// log!(6, "this is a custom logging level: {level}", level=6);
+/// ```
 #[macro_export]
 macro_rules! log(
     ($lvl:expr, $($arg:tt)+) => ({
@@ -21,26 +42,73 @@ macro_rules! log(
     })
 )
 
+/// A convenience macro for logging at the error log level. See `std::logging`
+/// for more information. about logging.
+///
+/// # Example
+///
+/// ```
+/// # let error = 3;
+/// error!("the build has failed with error code: {}", error);
+/// ```
 #[macro_export]
 macro_rules! error(
     ($($arg:tt)*) => (log!(1u32, $($arg)*))
 )
 
+/// A convenience macro for logging at the warning log level. See `std::logging`
+/// for more information. about logging.
+///
+/// # Example
+///
+/// ```
+/// # let code = 3;
+/// warn!("you may like to know that a process exited with: {}", code);
+/// ```
 #[macro_export]
 macro_rules! warn(
     ($($arg:tt)*) => (log!(2u32, $($arg)*))
 )
 
+/// A convenience macro for logging at the info log level. See `std::logging`
+/// for more information. about logging.
+///
+/// # Example
+///
+/// ```
+/// # let ret = 3;
+/// info!("this function is about to return: {}", ret);
+/// ```
 #[macro_export]
 macro_rules! info(
     ($($arg:tt)*) => (log!(3u32, $($arg)*))
 )
 
+/// A convenience macro for logging at the debug log level. See `std::logging`
+/// for more information. about logging.
+///
+/// # Example
+///
+/// ```
+/// debug!("x = {x}, y = {y}", x=10, y=20);
+/// ```
 #[macro_export]
 macro_rules! debug(
     ($($arg:tt)*) => (if cfg!(not(ndebug)) { log!(4u32, $($arg)*) })
 )
 
+/// A macro to test whether a log level is enabled for the current module.
+///
+/// # Example
+///
+/// ```
+/// # struct Point { x: int, y: int }
+/// # fn some_expensive_computation() -> Point { Point { x: 1, y: 2 } }
+/// if log_enabled!(std::logging::DEBUG) {
+///     let x = some_expensive_computation();
+///     debug!("x.x = {}, x.y = {}", x.x, x.y);
+/// }
+/// ```
 #[macro_export]
 macro_rules! log_enabled(
     ($lvl:expr) => ({
@@ -49,6 +117,24 @@ macro_rules! log_enabled(
     })
 )
 
+/// The entry point for failure of rust tasks.
+///
+/// This macro is used to inject failure into a rust task, causing the task to
+/// unwind and fail entirely. Each task's failure can be reaped as the `~Any`
+/// type, and the single-argument form of the `fail!` macro will be the value
+/// which is transmitted.
+///
+/// The multi-argument form of this macro fails with a string and has the
+/// `format!` sytnax for building a string.
+///
+/// # Example
+///
+/// ```should_fail
+/// fail!();
+/// fail!("this is a terrible mistake!");
+/// fail!(4); // fail with the value of 4 to be collected elsewhere
+/// fail!("this is a {} {message}", "fancy", message = "message");
+/// ```
 #[macro_export]
 macro_rules! fail(
     () => (
@@ -70,6 +156,26 @@ macro_rules! fail(
     });
 )
 
+/// Ensure that a boolean expression is `true` at runtime.
+///
+/// This will invoke the `fail!` macro if the provided expression cannot be
+/// evaluated to `true` at runtime.
+///
+/// # Example
+///
+/// ```
+/// // the failure message for these assertions is the stringified value of the
+/// // expression given.
+/// assert!(true);
+/// # fn some_computation() -> bool { true }
+/// assert!(some_computation());
+///
+/// // assert with a custom message
+/// # let x = true;
+/// assert!(x, "x wasn't true!");
+/// # let a = 3; let b = 27;
+/// assert!(a + b == 30, "a = {}, b = {}", a, b);
+/// ```
 #[macro_export]
 macro_rules! assert(
     ($cond:expr) => (
@@ -89,6 +195,18 @@ macro_rules! assert(
     );
 )
 
+/// Asserts that two expressions are equal to each other, testing equality in
+/// both directions.
+///
+/// On failure, this macro will print the values of the expressions.
+///
+/// # Example
+///
+/// ```
+/// let a = 3;
+/// let b = 1 + 2;
+/// assert_eq!(a, b);
+/// ```
 #[macro_export]
 macro_rules! assert_eq(
     ($given:expr , $expected:expr) => ({
@@ -136,6 +254,16 @@ macro_rules! unimplemented(
     () => (fail!("not yet implemented"))
 )
 
+/// Use the syntax described in `std::fmt` to create a value of type `~str`.
+/// See `std::fmt` for more information.
+///
+/// # Example
+///
+/// ```
+/// format!("test");
+/// format!("hello {}", "world!");
+/// format!("x = {}, y = {y}", 10, y = 30);
+/// ```
 #[macro_export]
 macro_rules! format(
     ($($arg:tt)*) => (
@@ -143,6 +271,19 @@ macro_rules! format(
     )
 )
 
+/// Use the `format!` syntax to write data into a buffer of type `&mut Writer`.
+/// See `std::fmt` for more information.
+///
+/// # Example
+///
+/// ```
+/// # #[allow(unused_must_use)];
+/// use std::io::MemWriter;
+///
+/// let mut w = MemWriter::new();
+/// write!(&mut w, "test");
+/// write!(&mut w, "formatted {}", "arguments");
+/// ```
 #[macro_export]
 macro_rules! write(
     ($dst:expr, $($arg:tt)*) => ({
@@ -151,6 +292,8 @@ macro_rules! write(
     })
 )
 
+/// Equivalent to the `write!` macro, except that a newline is appended after
+/// the message is written.
 #[macro_export]
 macro_rules! writeln(
     ($dst:expr, $($arg:tt)*) => ({
@@ -159,16 +302,42 @@ macro_rules! writeln(
     })
 )
 
+/// Equivalent to the `println!` macro except that a newline is not printed at
+/// the end of the message.
 #[macro_export]
 macro_rules! print(
     ($($arg:tt)*) => (format_args!(::std::io::stdio::print_args, $($arg)*))
 )
 
+/// Macro for printing to a task's stdout handle.
+///
+/// Each task can override its stdout handle via `std::io::stdio::set_stdout`.
+/// The syntax of this macro is the same as that used for `format!`. For more
+/// information, see `std::fmt` and `std::io::stdio`.
+///
+/// # Example
+///
+/// ```
+/// println!("hello there!");
+/// println!("format {} arguments", "some");
+/// ```
 #[macro_export]
 macro_rules! println(
     ($($arg:tt)*) => (format_args!(::std::io::stdio::println_args, $($arg)*))
 )
 
+/// Declare a task-local key with a specific type.
+///
+/// # Example
+///
+/// ```
+/// use std::local_data;
+///
+/// local_data_key!(my_integer: int)
+///
+/// local_data::set(my_integer, 2);
+/// local_data::get(my_integer, |val| println!("{}", val));
+/// ```
 #[macro_export]
 macro_rules! local_data_key(
     ($name:ident: $ty:ty) => (
@@ -179,6 +348,9 @@ macro_rules! local_data_key(
     );
 )
 
+/// Helper macro for unwrapping `Result` values while returning early with an
+/// error if the value of the expression is `Err`. For more information, see
+/// `std::io`.
 #[macro_export]
 macro_rules! if_ok(
     ($e:expr) => (match $e { Ok(e) => e, Err(e) => return Err(e) })