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::BTreeMap;
  13
  14 use ast;
  15 use ast::{Ident, Name, TokenTree};
  16 use codemap::Span;
  17 use ext::base::{ExtCtxt, MacExpr, MacResult, MacItems};
  18 use ext::build::AstBuilder;
  19 use parse::token;
  20 use ptr::P;
  21
  22 thread_local! {
  23     static REGISTERED_DIAGNOSTICS: RefCell<BTreeMap<Name, Option<Name>>> = {
  24         RefCell::new(BTreeMap::new())
  25     }
  26 }
  27 thread_local! {
  28     static USED_DIAGNOSTICS: RefCell<BTreeMap<Name, Span>> = {
  29         RefCell::new(BTreeMap::new())
  30     }
  31 }
  32
  33 fn with_registered_diagnostics<T, F>(f: F) -> T where
  34     F: FnOnce(&mut BTreeMap<Name, Option<Name>>) -> T,
  35 {
  36     REGISTERED_DIAGNOSTICS.with(move |slot| {
  37         f(&mut *slot.borrow_mut())
  38     })
  39 }
  40
  41 fn with_used_diagnostics<T, F>(f: F) -> T where
  42     F: FnOnce(&mut BTreeMap<Name, Span>) -> T,
  43 {
  44     USED_DIAGNOSTICS.with(move |slot| {
  45         f(&mut *slot.borrow_mut())
  46     })
  47 }
  48
  49 pub fn expand_diagnostic_used<'cx>(ecx: &'cx mut ExtCtxt,
  50                                    span: Span,
  51                                    token_tree: &[TokenTree])
  52                                    -> Box<MacResult+'cx> {
  53     let code = match token_tree {
  54         [ast::TtToken(_, token::Ident(code, _))] => code,
  55         _ => unreachable!()
  56     };
  57     with_used_diagnostics(|diagnostics| {
  58         match diagnostics.insert(code.name, span) {
  59             Some(previous_span) => {
  60                 ecx.span_warn(span, &format!(
  61                     "diagnostic code {} already used", &token::get_ident(code)
  62                 ));
  63                 ecx.span_note(previous_span, "previous invocation");
  64             },
  65             None => ()
  66         }
  67         ()
  68     });
  69     with_registered_diagnostics(|diagnostics| {
  70         if !diagnostics.contains_key(&code.name) {
  71             ecx.span_err(span, &format!(
  72                 "used diagnostic code {} not registered", &token::get_ident(code)
  73             ));
  74         }
  75     });
  76     MacExpr::new(quote_expr!(ecx, ()))
  77 }
  78
  79 pub fn expand_register_diagnostic<'cx>(ecx: &'cx mut ExtCtxt,
  80                                        span: Span,
  81                                        token_tree: &[TokenTree])
  82                                        -> Box<MacResult+'cx> {
  83     let (code, description) = match token_tree {
  84         [ast::TtToken(_, token::Ident(ref code, _))] => {
  85             (code, None)
  86         },
  87         [ast::TtToken(_, token::Ident(ref code, _)),
  88          ast::TtToken(_, token::Comma),
  89          ast::TtToken(_, token::Literal(token::StrRaw(description, _), None))] => {
  90             (code, Some(description))
  91         }
  92         _ => unreachable!()
  93     };
  94     with_registered_diagnostics(|diagnostics| {
  95         if diagnostics.insert(code.name, description).is_some() {
  96             ecx.span_err(span, &format!(
  97                 "diagnostic code {} already registered", &token::get_ident(*code)
  98             ));
  99         }
 100     });
 101     let sym = Ident::new(token::gensym(&(
 102         "__register_diagnostic_".to_string() + &token::get_ident(*code)
 103     )));
 104     MacItems::new(vec![quote_item!(ecx, mod $sym {}).unwrap()].into_iter())
 105 }
 106
 107 pub fn expand_build_diagnostic_array<'cx>(ecx: &'cx mut ExtCtxt,
 108                                           span: Span,
 109                                           token_tree: &[TokenTree])
 110                                           -> Box<MacResult+'cx> {
 111     let name = match token_tree {
 112         [ast::TtToken(_, token::Ident(ref name, _))] => name,
 113         _ => unreachable!()
 114     };
 115
 116     let (count, expr) =
 117         with_registered_diagnostics(|diagnostics| {
 118             let descriptions: Vec<P<ast::Expr>> =
 119                 diagnostics.iter().filter_map(|(code, description)| {
 120                     description.map(|description| {
 121                         ecx.expr_tuple(span, vec![
 122                             ecx.expr_str(span, token::get_name(*code)),
 123                             ecx.expr_str(span, token::get_name(description))])
 124                     })
 125                 }).collect();
 126             (descriptions.len(), ecx.expr_vec(span, descriptions))
 127         });
 128
 129     MacItems::new(vec![quote_item!(ecx,
 130         pub static $name: [(&'static str, &'static str); $count] = $expr;
 131     ).unwrap()].into_iter())
 132 }