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!(static REGISTERED_DIAGNOSTICS: RefCell<HashMap<Name, Option<Name>>> = {
  22     RefCell::new(HashMap::new())
  23 })
  24 thread_local!(static USED_DIAGNOSTICS: RefCell<HashMap<Name, Span>> = {
  25     RefCell::new(HashMap::new())
  26 })
  27
  28 fn with_registered_diagnostics<T>(f: |&mut HashMap<Name, Option<Name>>| -> T) -> T {
  29     REGISTERED_DIAGNOSTICS.with(|slot| {
  30         f(&mut *slot.borrow_mut())
  31     })
  32 }
  33
  34 fn with_used_diagnostics<T>(f: |&mut HashMap<Name, Span>| -> T) -> T {
  35     USED_DIAGNOSTICS.with(|slot| {
  36         f(&mut *slot.borrow_mut())
  37     })
  38 }
  39
  40 pub fn expand_diagnostic_used<'cx>(ecx: &'cx mut ExtCtxt,
  41                                    span: Span,
  42                                    token_tree: &[TokenTree])
  43                                    -> Box<MacResult+'cx> {
  44     let code = match token_tree {
  45         [ast::TtToken(_, token::Ident(code, _))] => code,
  46         _ => unreachable!()
  47     };
  48     with_registered_diagnostics(|diagnostics| {
  49         if !diagnostics.contains_key(&code.name) {
  50             ecx.span_err(span, format!(
  51                 "unknown diagnostic code {}; add to librustc/diagnostics.rs",
  52                 token::get_ident(code).get()
  53             ).as_slice());
  54         }
  55         ()
  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).get()
  62                 ).as_slice());
  63                 ecx.span_note(previous_span, "previous invocation");
  64             },
  65             None => ()
  66         }
  67         ()
  68     });
  69     MacExpr::new(quote_expr!(ecx, ()))
  70 }
  71
  72 pub fn expand_register_diagnostic<'cx>(ecx: &'cx mut ExtCtxt,
  73                                        span: Span,
  74                                        token_tree: &[TokenTree])
  75                                        -> Box<MacResult+'cx> {
  76     let (code, description) = match token_tree {
  77         [ast::TtToken(_, token::Ident(ref code, _))] => {
  78             (code, None)
  79         },
  80         [ast::TtToken(_, token::Ident(ref code, _)),
  81          ast::TtToken(_, token::Comma),
  82          ast::TtToken(_, token::Literal(token::StrRaw(description, _), None))] => {
  83             (code, Some(description))
  84         }
  85         _ => unreachable!()
  86     };
  87     with_registered_diagnostics(|diagnostics| {
  88         if diagnostics.insert(code.name, description).is_some() {
  89             ecx.span_err(span, format!(
  90                 "diagnostic code {} already registered", token::get_ident(*code).get()
  91             ).as_slice());
  92         }
  93     });
  94     let sym = Ident::new(token::gensym((
  95         "__register_diagnostic_".to_string() + token::get_ident(*code).get()
  96     ).as_slice()));
  97     MacItems::new(vec![quote_item!(ecx, mod $sym {}).unwrap()].into_iter())
  98 }
  99
 100 pub fn expand_build_diagnostic_array<'cx>(ecx: &'cx mut ExtCtxt,
 101                                           span: Span,
 102                                           token_tree: &[TokenTree])
 103                                           -> Box<MacResult+'cx> {
 104     let name = match token_tree {
 105         [ast::TtToken(_, token::Ident(ref name, _))] => name,
 106         _ => unreachable!()
 107     };
 108
 109     let (count, expr) = with_used_diagnostics(|diagnostics_in_use| {
 110         with_registered_diagnostics(|diagnostics| {
 111             let descriptions: Vec<P<ast::Expr>> = diagnostics
 112                 .iter().filter_map(|(code, description)| {
 113                 if !diagnostics_in_use.contains_key(code) {
 114                     ecx.span_warn(span, format!(
 115                         "diagnostic code {} never used", token::get_name(*code).get()
 116                     ).as_slice());
 117                 }
 118                 description.map(|description| {
 119                     ecx.expr_tuple(span, vec![
 120                         ecx.expr_str(span, token::get_name(*code)),
 121                         ecx.expr_str(span, token::get_name(description))
 122                     ])
 123                 })
 124             }).collect();
 125             (descriptions.len(), ecx.expr_vec(span, descriptions))
 126         })
 127     });
 128     MacItems::new(vec![quote_item!(ecx,
 129         pub static $name: [(&'static str, &'static str), ..$count] = $expr;
 130     ).unwrap()].into_iter())
 131 }