src/libsyntax/diagnostics/plugin.rs

   1 // Copyright 2014 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 use std::cell::RefCell;
  12 use std::collections::HashMap;
  13 use ast;
  14 use ast::{Ident, Name, TokenTree};
  15 use codemap::Span;
  16 use ext::base::{ExtCtxt, MacExpr, MacResult, MacItems};
  17 use ext::build::AstBuilder;
  18 use parse::token;
  19 use ptr::P;
  20
  21 thread_local! {
  22     static REGISTERED_DIAGNOSTICS: RefCell<HashMap<Name, Option<Name>>> = {
  23         RefCell::new(HashMap::new())
  24     }
  25 }
  26 thread_local! {
  27     static USED_DIAGNOSTICS: RefCell<HashMap<Name, Span>> = {
  28         RefCell::new(HashMap::new())
  29     }
  30 }
  31
  32 fn with_registered_diagnostics<T, F>(f: F) -> T where
  33     F: FnOnce(&mut HashMap<Name, Option<Name>>) -> T,
  34 {
  35     REGISTERED_DIAGNOSTICS.with(move |slot| {
  36         f(&mut *slot.borrow_mut())
  37     })
  38 }
  39
  40 fn with_used_diagnostics<T, F>(f: F) -> T where
  41     F: FnOnce(&mut HashMap<Name, Span>) -> T,
  42 {
  43     USED_DIAGNOSTICS.with(move |slot| {
  44         f(&mut *slot.borrow_mut())
  45     })
  46 }
  47
  48 pub fn expand_diagnostic_used<'cx>(ecx: &'cx mut ExtCtxt,
  49                                    span: Span,
  50                                    token_tree: &[TokenTree])
  51                                    -> Box<MacResult+'cx> {
  52     let code = match token_tree {
  53         [ast::TtToken(_, token::Ident(code, _))] => code,
  54         _ => unreachable!()
  55     };
  56     with_used_diagnostics(|diagnostics| {
  57         match diagnostics.insert(code.name, span) {
  58             Some(previous_span) => {
  59                 ecx.span_warn(span, format!(
  60                     "diagnostic code {} already used", token::get_ident(code).get()
  61                 ).index(&FullRange));
  62                 ecx.span_note(previous_span, "previous invocation");
  63             },
  64             None => ()
  65         }
  66         ()
  67     });
  68     MacExpr::new(quote_expr!(ecx, ()))
  69 }
  70
  71 pub fn expand_register_diagnostic<'cx>(ecx: &'cx mut ExtCtxt,
  72                                        span: Span,
  73                                        token_tree: &[TokenTree])
  74                                        -> Box<MacResult+'cx> {
  75     let (code, description) = match token_tree {
  76         [ast::TtToken(_, token::Ident(ref code, _))] => {
  77             (code, None)
  78         },
  79         [ast::TtToken(_, token::Ident(ref code, _)),
  80          ast::TtToken(_, token::Comma),
  81          ast::TtToken(_, token::Literal(token::StrRaw(description, _), None))] => {
  82             (code, Some(description))
  83         }
  84         _ => unreachable!()
  85     };
  86     with_registered_diagnostics(|diagnostics| {
  87         if diagnostics.insert(code.name, description).is_some() {
  88             ecx.span_err(span, format!(
  89                 "diagnostic code {} already registered", token::get_ident(*code).get()
  90             ).index(&FullRange));
  91         }
  92     });
  93     let sym = Ident::new(token::gensym((
  94         "__register_diagnostic_".to_string() + token::get_ident(*code).get()
  95     ).index(&FullRange)));
  96     MacItems::new(vec![quote_item!(ecx, mod $sym {}).unwrap()].into_iter())
  97 }
  98
  99 pub fn expand_build_diagnostic_array<'cx>(ecx: &'cx mut ExtCtxt,
 100                                           span: Span,
 101                                           token_tree: &[TokenTree])
 102                                           -> Box<MacResult+'cx> {
 103     let name = match token_tree {
 104         [ast::TtToken(_, token::Ident(ref name, _))] => name,
 105         _ => unreachable!()
 106     };
 107
 108     let (count, expr) =
 109         with_registered_diagnostics(|diagnostics| {
 110             let descriptions: Vec<P<ast::Expr>> =
 111                 diagnostics.iter().filter_map(|(code, description)| {
 112                     description.map(|description| {
 113                         ecx.expr_tuple(span, vec![
 114                             ecx.expr_str(span, token::get_name(*code)),
 115                             ecx.expr_str(span, token::get_name(description))])
 116                     })
 117                 }).collect();
 118             (descriptions.len(), ecx.expr_vec(span, descriptions))
 119         });
 120
 121     MacItems::new(vec![quote_item!(ecx,
 122         pub static $name: [(&'static str, &'static str); $count] = $expr;
 123     ).unwrap()].into_iter())
 124 }