src/librustc/plugin/registry.rs

   1 // Copyright 2012-2013 The Rust Project Developers. See the COPYRIGHT
   2 // file at the top-level directory of this distribution and at
   3 // http://rust-lang.org/COPYRIGHT.
   4 //
   5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
   6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
   7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
   8 // option. This file may not be copied, modified, or distributed
   9 // except according to those terms.
  10
  11 //! Used by plugin crates to tell `rustc` about the plugins they provide.
  12
  13 use lint::{LintPassObject, LintId, Lint};
  14 use session::Session;
  15
  16 use syntax::ext::base::{SyntaxExtension, NamedSyntaxExtension, NormalTT};
  17 use syntax::ext::base::{IdentTT, Decorator, Modifier, MultiModifier, MacroRulesTT};
  18 use syntax::ext::base::MacroExpanderFn;
  19 use syntax::codemap::Span;
  20 use syntax::parse::token;
  21 use syntax::ptr::P;
  22 use syntax::ast;
  23
  24 use std::collections::HashMap;
  25
  26 /// Structure used to register plugins.
  27 ///
  28 /// A plugin registrar function takes an `&mut Registry` and should call
  29 /// methods to register its plugins.
  30 ///
  31 /// This struct has public fields and other methods for use by `rustc`
  32 /// itself. They are not documented here, and plugin authors should
  33 /// not use them.
  34 pub struct Registry<'a> {
  35     /// Compiler session. Useful if you want to emit diagnostic messages
  36     /// from the plugin registrar.
  37     pub sess: &'a Session,
  38
  39     #[doc(hidden)]
  40     pub args_hidden: Option<Vec<P<ast::MetaItem>>>,
  41
  42     #[doc(hidden)]
  43     pub krate_span: Span,
  44
  45     #[doc(hidden)]
  46     pub syntax_exts: Vec<NamedSyntaxExtension>,
  47
  48     #[doc(hidden)]
  49     pub lint_passes: Vec<LintPassObject>,
  50
  51     #[doc(hidden)]
  52     pub lint_groups: HashMap<&'static str, Vec<LintId>>,
  53 }
  54
  55 impl<'a> Registry<'a> {
  56     #[doc(hidden)]
  57     pub fn new(sess: &'a Session, krate: &ast::Crate) -> Registry<'a> {
  58         Registry {
  59             sess: sess,
  60             args_hidden: None,
  61             krate_span: krate.span,
  62             syntax_exts: vec!(),
  63             lint_passes: vec!(),
  64             lint_groups: HashMap::new(),
  65         }
  66     }
  67
  68     /// Get the plugin's arguments, if any.
  69     ///
  70     /// These are specified inside the `plugin` crate attribute as
  71     ///
  72     /// ```no_run
  73     /// #![plugin(my_plugin_name(... args ...))]
  74     /// ```
  75     pub fn args<'b>(&'b self) -> &'b Vec<P<ast::MetaItem>> {
  76         self.args_hidden.as_ref().expect("args not set")
  77     }
  78
  79     /// Register a syntax extension of any kind.
  80     ///
  81     /// This is the most general hook into `libsyntax`'s expansion behavior.
  82     pub fn register_syntax_extension(&mut self, name: ast::Name, extension: SyntaxExtension) {
  83         self.syntax_exts.push((name, match extension {
  84             NormalTT(ext, _, allow_internal_unstable) => {
  85                 NormalTT(ext, Some(self.krate_span), allow_internal_unstable)
  86             }
  87             IdentTT(ext, _, allow_internal_unstable) => {
  88                 IdentTT(ext, Some(self.krate_span), allow_internal_unstable)
  89             }
  90             Decorator(ext) => Decorator(ext),
  91             Modifier(ext) => Modifier(ext),
  92             MultiModifier(ext) => MultiModifier(ext),
  93             MacroRulesTT => {
  94                 self.sess.err("plugin tried to register a new MacroRulesTT");
  95                 return;
  96             }
  97         }));
  98     }
  99
 100     /// Register a macro of the usual kind.
 101     ///
 102     /// This is a convenience wrapper for `register_syntax_extension`.
 103     /// It builds for you a `NormalTT` that calls `expander`,
 104     /// and also takes care of interning the macro's name.
 105     pub fn register_macro(&mut self, name: &str, expander: MacroExpanderFn) {
 106         self.register_syntax_extension(token::intern(name),
 107                                        NormalTT(Box::new(expander), None, false));
 108     }
 109
 110     /// Register a compiler lint pass.
 111     pub fn register_lint_pass(&mut self, lint_pass: LintPassObject) {
 112         self.lint_passes.push(lint_pass);
 113     }
 114
 115     /// Register a lint group.
 116     pub fn register_lint_group(&mut self, name: &'static str, to: Vec<&'static Lint>) {
 117         self.lint_groups.insert(name, to.into_iter().map(|x| LintId::of(x)).collect());
 118     }
 119 }