src/libsyntax/ext/deriving/mod.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 //! The compiler code necessary to implement the `#[derive]` extensions.
  12 //!
  13 //! FIXME (#2810): hygiene. Search for "__" strings (in other files too). We also assume "extra" is
  14 //! the standard library, and "std" is the core library.
  15
  16 use ast::{Item, MetaItem, MetaList, MetaNameValue, MetaWord};
  17 use ext::base::ExtCtxt;
  18 use codemap::Span;
  19 use ptr::P;
  20
  21 pub mod bounds;
  22 pub mod clone;
  23 pub mod encodable;
  24 pub mod decodable;
  25 pub mod hash;
  26 pub mod rand;
  27 pub mod show;
  28 pub mod default;
  29 pub mod primitive;
  30
  31 #[path="cmp/eq.rs"]
  32 pub mod eq;
  33 #[path="cmp/totaleq.rs"]
  34 pub mod totaleq;
  35 #[path="cmp/ord.rs"]
  36 pub mod ord;
  37 #[path="cmp/totalord.rs"]
  38 pub mod totalord;
  39
  40
  41 pub mod generic;
  42
  43 pub fn expand_meta_derive(cx: &mut ExtCtxt,
  44                           _span: Span,
  45                           mitem: &MetaItem,
  46                           item: &Item,
  47                           mut push: Box<FnMut(P<Item>)>) {
  48     match mitem.node {
  49         MetaNameValue(_, ref l) => {
  50             cx.span_err(l.span, "unexpected value in `derive`");
  51         }
  52         MetaWord(_) => {
  53             cx.span_warn(mitem.span, "empty trait list in `derive`");
  54         }
  55         MetaList(_, ref titems) if titems.len() == 0 => {
  56             cx.span_warn(mitem.span, "empty trait list in `derive`");
  57         }
  58         MetaList(_, ref titems) => {
  59             for titem in titems.iter().rev() {
  60                 match titem.node {
  61                     MetaNameValue(ref tname, _) |
  62                     MetaList(ref tname, _) |
  63                     MetaWord(ref tname) => {
  64                         macro_rules! expand {
  65                             ($func:path) => ($func(cx, titem.span, &**titem, item,
  66                                                    |i| push(i)))
  67                         }
  68
  69                         match tname.get() {
  70                             "Clone" => expand!(clone::expand_deriving_clone),
  71
  72                             "Hash" => expand!(hash::expand_deriving_hash),
  73
  74                             "RustcEncodable" => {
  75                                 expand!(encodable::expand_deriving_rustc_encodable)
  76                             }
  77                             "RustcDecodable" => {
  78                                 expand!(decodable::expand_deriving_rustc_decodable)
  79                             }
  80                             "Encodable" => {
  81                                 cx.span_warn(titem.span,
  82                                              "derive(Encodable) is deprecated \
  83                                               in favor of derive(RustcEncodable)");
  84
  85                                 expand!(encodable::expand_deriving_encodable)
  86                             }
  87                             "Decodable" => {
  88                                 cx.span_warn(titem.span,
  89                                              "derive(Decodable) is deprecated \
  90                                               in favor of derive(RustcDecodable)");
  91
  92                                 expand!(decodable::expand_deriving_decodable)
  93                             }
  94
  95                             "PartialEq" => expand!(eq::expand_deriving_eq),
  96                             "Eq" => expand!(totaleq::expand_deriving_totaleq),
  97                             "PartialOrd" => expand!(ord::expand_deriving_ord),
  98                             "Ord" => expand!(totalord::expand_deriving_totalord),
  99
 100                             "Rand" => expand!(rand::expand_deriving_rand),
 101
 102                             "Show" => expand!(show::expand_deriving_show),
 103
 104                             "Default" => expand!(default::expand_deriving_default),
 105
 106                             "FromPrimitive" => expand!(primitive::expand_deriving_from_primitive),
 107
 108                             "Send" => expand!(bounds::expand_deriving_bound),
 109                             "Sync" => expand!(bounds::expand_deriving_bound),
 110                             "Copy" => expand!(bounds::expand_deriving_bound),
 111
 112                             ref tname => {
 113                                 cx.span_err(titem.span,
 114                                             &format!("unknown `derive` \
 115                                                      trait: `{}`",
 116                                                     *tname)[]);
 117                             }
 118                         };
 119                     }
 120                 }
 121             }
 122         }
 123     }
 124 }