compiler/rustc_macros/src/lib.rs

   1 #![feature(allow_internal_unstable)]
   2 #![feature(never_type)]
   3 #![feature(proc_macro_diagnostic)]
   4 #![feature(proc_macro_span)]
   5 #![allow(rustc::default_hash_types)]
   6 #![deny(rustc::untranslatable_diagnostic)]
   7 #![deny(rustc::diagnostic_outside_of_impl)]
   8 #![recursion_limit = "128"]
   9
  10 use synstructure::decl_derive;
  11
  12 use proc_macro::TokenStream;
  13
  14 mod diagnostics;
  15 mod hash_stable;
  16 mod lift;
  17 mod newtype;
  18 mod query;
  19 mod serialize;
  20 mod symbols;
  21 mod type_foldable;
  22 mod type_visitable;
  23
  24 #[proc_macro]
  25 pub fn rustc_queries(input: TokenStream) -> TokenStream {
  26     query::rustc_queries(input)
  27 }
  28
  29 #[proc_macro]
  30 pub fn symbols(input: TokenStream) -> TokenStream {
  31     symbols::symbols(input.into()).into()
  32 }
  33
  34 /// Creates a struct type `S` that can be used as an index with
  35 /// `IndexVec` and so on.
  36 ///
  37 /// There are two ways of interacting with these indices:
  38 ///
  39 /// - The `From` impls are the preferred way. So you can do
  40 ///   `S::from(v)` with a `usize` or `u32`. And you can convert back
  41 ///   to an integer with `u32::from(s)`.
  42 ///
  43 /// - Alternatively, you can use the methods `S::new(v)` and `s.index()`
  44 ///   to create/return a value.
  45 ///
  46 /// Internally, the index uses a u32, so the index must not exceed
  47 /// `u32::MAX`. You can also customize things like the `Debug` impl,
  48 /// what traits are derived, and so forth via the macro.
  49 #[proc_macro]
  50 #[allow_internal_unstable(step_trait, rustc_attrs, trusted_step)]
  51 pub fn newtype_index(input: TokenStream) -> TokenStream {
  52     newtype::newtype(input)
  53 }
  54
  55 /// Implements the `fluent_messages` macro, which performs compile-time validation of the
  56 /// compiler's Fluent resources (i.e. that the resources parse and don't multiply define the same
  57 /// messages) and generates constants that make using those messages in diagnostics more ergonomic.
  58 ///
  59 /// For example, given the following invocation of the macro..
  60 ///
  61 /// ```ignore (rust)
  62 /// fluent_messages! {
  63 ///     typeck => "./typeck.ftl",
  64 /// }
  65 /// ```
  66 /// ..where `typeck.ftl` has the following contents..
  67 ///
  68 /// ```fluent
  69 /// typeck_field_multiply_specified_in_initializer =
  70 ///     field `{$ident}` specified more than once
  71 ///     .label = used more than once
  72 ///     .label_previous_use = first use of `{$ident}`
  73 /// ```
  74 /// ...then the macro parse the Fluent resource, emitting a diagnostic if it fails to do so, and
  75 /// will generate the following code:
  76 ///
  77 /// ```ignore (rust)
  78 /// pub static DEFAULT_LOCALE_RESOURCES: &'static [&'static str] = &[
  79 ///     include_str!("./typeck.ftl"),
  80 /// ];
  81 ///
  82 /// mod fluent_generated {
  83 ///     mod typeck {
  84 ///         pub const field_multiply_specified_in_initializer: DiagnosticMessage =
  85 ///             DiagnosticMessage::fluent("typeck_field_multiply_specified_in_initializer");
  86 ///         pub const field_multiply_specified_in_initializer_label_previous_use: DiagnosticMessage =
  87 ///             DiagnosticMessage::fluent_attr(
  88 ///                 "typeck_field_multiply_specified_in_initializer",
  89 ///                 "previous_use_label"
  90 ///             );
  91 ///     }
  92 /// }
  93 /// ```
  94 /// When emitting a diagnostic, the generated constants can be used as follows:
  95 ///
  96 /// ```ignore (rust)
  97 /// let mut err = sess.struct_span_err(
  98 ///     span,
  99 ///     fluent::typeck::field_multiply_specified_in_initializer
 100 /// );
 101 /// err.span_default_label(span);
 102 /// err.span_label(
 103 ///     previous_use_span,
 104 ///     fluent::typeck::field_multiply_specified_in_initializer_label_previous_use
 105 /// );
 106 /// err.emit();
 107 /// ```
 108 #[proc_macro]
 109 pub fn fluent_messages(input: TokenStream) -> TokenStream {
 110     diagnostics::fluent_messages(input)
 111 }
 112
 113 decl_derive!([HashStable, attributes(stable_hasher)] => hash_stable::hash_stable_derive);
 114 decl_derive!(
 115     [HashStable_Generic, attributes(stable_hasher)] =>
 116     hash_stable::hash_stable_generic_derive
 117 );
 118
 119 decl_derive!([Decodable] => serialize::decodable_derive);
 120 decl_derive!([Encodable] => serialize::encodable_derive);
 121 decl_derive!([TyDecodable] => serialize::type_decodable_derive);
 122 decl_derive!([TyEncodable] => serialize::type_encodable_derive);
 123 decl_derive!([MetadataDecodable] => serialize::meta_decodable_derive);
 124 decl_derive!([MetadataEncodable] => serialize::meta_encodable_derive);
 125 decl_derive!([TypeFoldable, attributes(type_foldable)] => type_foldable::type_foldable_derive);
 126 decl_derive!([TypeVisitable, attributes(type_visitable)] => type_visitable::type_visitable_derive);
 127 decl_derive!([Lift, attributes(lift)] => lift::lift_derive);
 128 decl_derive!(
 129     [Diagnostic, attributes(
 130         // struct attributes
 131         diag,
 132         help,
 133         note,
 134         warning,
 135         // field attributes
 136         skip_arg,
 137         primary_span,
 138         label,
 139         subdiagnostic,
 140         suggestion,
 141         suggestion_short,
 142         suggestion_hidden,
 143         suggestion_verbose)] => diagnostics::session_diagnostic_derive
 144 );
 145 decl_derive!(
 146     [LintDiagnostic, attributes(
 147         // struct attributes
 148         diag,
 149         help,
 150         note,
 151         warning,
 152         // field attributes
 153         skip_arg,
 154         primary_span,
 155         label,
 156         subdiagnostic,
 157         suggestion,
 158         suggestion_short,
 159         suggestion_hidden,
 160         suggestion_verbose)] => diagnostics::lint_diagnostic_derive
 161 );
 162 decl_derive!(
 163     [Subdiagnostic, attributes(
 164         // struct/variant attributes
 165         label,
 166         help,
 167         note,
 168         warning,
 169         suggestion,
 170         suggestion_short,
 171         suggestion_hidden,
 172         suggestion_verbose,
 173         multipart_suggestion,
 174         multipart_suggestion_short,
 175         multipart_suggestion_hidden,
 176         multipart_suggestion_verbose,
 177         // field attributes
 178         skip_arg,
 179         primary_span,
 180         suggestion_part,
 181         applicability)] => diagnostics::session_subdiagnostic_derive
 182 );