compiler/rustc_macros/src/lib.rs

   1 #![feature(allow_internal_unstable)]
   2 #![feature(let_else)]
   3 #![feature(never_type)]
   4 #![feature(proc_macro_diagnostic)]
   5 #![feature(proc_macro_span)]
   6 #![allow(rustc::default_hash_types)]
   7 #![recursion_limit = "128"]
   8
   9 use synstructure::decl_derive;
  10
  11 use proc_macro::TokenStream;
  12
  13 mod diagnostics;
  14 mod hash_stable;
  15 mod lift;
  16 mod newtype;
  17 mod query;
  18 mod serialize;
  19 mod symbols;
  20 mod type_foldable;
  21 mod type_visitable;
  22
  23 #[proc_macro]
  24 pub fn rustc_queries(input: TokenStream) -> TokenStream {
  25     query::rustc_queries(input)
  26 }
  27
  28 #[proc_macro]
  29 pub fn symbols(input: TokenStream) -> TokenStream {
  30     symbols::symbols(input.into()).into()
  31 }
  32
  33 /// Creates a struct type `S` that can be used as an index with
  34 /// `IndexVec` and so on.
  35 ///
  36 /// There are two ways of interacting with these indices:
  37 ///
  38 /// - The `From` impls are the preferred way. So you can do
  39 ///   `S::from(v)` with a `usize` or `u32`. And you can convert back
  40 ///   to an integer with `u32::from(s)`.
  41 ///
  42 /// - Alternatively, you can use the methods `S::new(v)` and `s.index()`
  43 ///   to create/return a value.
  44 ///
  45 /// Internally, the index uses a u32, so the index must not exceed
  46 /// `u32::MAX`. You can also customize things like the `Debug` impl,
  47 /// what traits are derived, and so forth via the macro.
  48 #[proc_macro]
  49 #[allow_internal_unstable(step_trait, rustc_attrs, trusted_step)]
  50 pub fn newtype_index(input: TokenStream) -> TokenStream {
  51     newtype::newtype(input)
  52 }
  53
  54 /// Implements the `fluent_messages` macro, which performs compile-time validation of the
  55 /// compiler's Fluent resources (i.e. that the resources parse and don't multiply define the same
  56 /// messages) and generates constants that make using those messages in diagnostics more ergonomic.
  57 ///
  58 /// For example, given the following invocation of the macro..
  59 ///
  60 /// ```ignore (rust)
  61 /// fluent_messages! {
  62 ///     typeck => "./typeck.ftl",
  63 /// }
  64 /// ```
  65 /// ..where `typeck.ftl` has the following contents..
  66 ///
  67 /// ```fluent
  68 /// typeck_field_multiply_specified_in_initializer =
  69 ///     field `{$ident}` specified more than once
  70 ///     .label = used more than once
  71 ///     .label_previous_use = first use of `{$ident}`
  72 /// ```
  73 /// ...then the macro parse the Fluent resource, emitting a diagnostic if it fails to do so, and
  74 /// will generate the following code:
  75 ///
  76 /// ```ignore (rust)
  77 /// pub static DEFAULT_LOCALE_RESOURCES: &'static [&'static str] = &[
  78 ///     include_str!("./typeck.ftl"),
  79 /// ];
  80 ///
  81 /// mod fluent_generated {
  82 ///     mod typeck {
  83 ///         pub const field_multiply_specified_in_initializer: DiagnosticMessage =
  84 ///             DiagnosticMessage::fluent("typeck_field_multiply_specified_in_initializer");
  85 ///         pub const field_multiply_specified_in_initializer_label_previous_use: DiagnosticMessage =
  86 ///             DiagnosticMessage::fluent_attr(
  87 ///                 "typeck_field_multiply_specified_in_initializer",
  88 ///                 "previous_use_label"
  89 ///             );
  90 ///     }
  91 /// }
  92 /// ```
  93 /// When emitting a diagnostic, the generated constants can be used as follows:
  94 ///
  95 /// ```ignore (rust)
  96 /// let mut err = sess.struct_span_err(
  97 ///     span,
  98 ///     fluent::typeck::field_multiply_specified_in_initializer
  99 /// );
 100 /// err.span_default_label(span);
 101 /// err.span_label(
 102 ///     previous_use_span,
 103 ///     fluent::typeck::field_multiply_specified_in_initializer_label_previous_use
 104 /// );
 105 /// err.emit();
 106 /// ```
 107 #[proc_macro]
 108 pub fn fluent_messages(input: TokenStream) -> TokenStream {
 109     diagnostics::fluent_messages(input)
 110 }
 111
 112 decl_derive!([HashStable, attributes(stable_hasher)] => hash_stable::hash_stable_derive);
 113 decl_derive!(
 114     [HashStable_Generic, attributes(stable_hasher)] =>
 115     hash_stable::hash_stable_generic_derive
 116 );
 117
 118 decl_derive!([Decodable] => serialize::decodable_derive);
 119 decl_derive!([Encodable] => serialize::encodable_derive);
 120 decl_derive!([TyDecodable] => serialize::type_decodable_derive);
 121 decl_derive!([TyEncodable] => serialize::type_encodable_derive);
 122 decl_derive!([MetadataDecodable] => serialize::meta_decodable_derive);
 123 decl_derive!([MetadataEncodable] => serialize::meta_encodable_derive);
 124 decl_derive!([TypeFoldable, attributes(type_foldable)] => type_foldable::type_foldable_derive);
 125 decl_derive!([TypeVisitable, attributes(type_visitable)] => type_visitable::type_visitable_derive);
 126 decl_derive!([Lift, attributes(lift)] => lift::lift_derive);
 127 decl_derive!(
 128     [SessionDiagnostic, attributes(
 129         // struct attributes
 130         warning,
 131         error,
 132         lint,
 133         help,
 134         note,
 135         warn_,
 136         // field attributes
 137         skip_arg,
 138         primary_span,
 139         label,
 140         subdiagnostic,
 141         suggestion,
 142         suggestion_short,
 143         suggestion_hidden,
 144         suggestion_verbose)] => diagnostics::session_diagnostic_derive
 145 );
 146 decl_derive!(
 147     [LintDiagnostic, attributes(
 148         // struct attributes
 149         warning,
 150         error,
 151         lint,
 152         help,
 153         note,
 154         warn_,
 155         // field attributes
 156         skip_arg,
 157         primary_span,
 158         label,
 159         subdiagnostic,
 160         suggestion,
 161         suggestion_short,
 162         suggestion_hidden,
 163         suggestion_verbose)] => diagnostics::lint_diagnostic_derive
 164 );
 165 decl_derive!(
 166     [SessionSubdiagnostic, attributes(
 167         // struct/variant attributes
 168         label,
 169         help,
 170         note,
 171         warn_,
 172         suggestion,
 173         suggestion_short,
 174         suggestion_hidden,
 175         suggestion_verbose,
 176         // field attributes
 177         skip_arg,
 178         primary_span,
 179         applicability)] => diagnostics::session_subdiagnostic_derive
 180 );