compiler/rustc_macros/src/lib.rs

   1 #![feature(allow_internal_unstable)]
   2 #![feature(if_let_guard)]
   3 #![feature(never_type)]
   4 #![feature(proc_macro_diagnostic)]
   5 #![feature(proc_macro_span)]
   6 #![allow(rustc::default_hash_types)]
   7 #![deny(rustc::untranslatable_diagnostic)]
   8 #![deny(rustc::diagnostic_outside_of_impl)]
   9 #![recursion_limit = "128"]
  10
  11 use synstructure::decl_derive;
  12
  13 use proc_macro::TokenStream;
  14
  15 mod diagnostics;
  16 mod hash_stable;
  17 mod lift;
  18 mod newtype;
  19 mod query;
  20 mod serialize;
  21 mod symbols;
  22 mod type_foldable;
  23 mod type_visitable;
  24
  25 #[proc_macro]
  26 pub fn rustc_queries(input: TokenStream) -> TokenStream {
  27     query::rustc_queries(input)
  28 }
  29
  30 #[proc_macro]
  31 pub fn symbols(input: TokenStream) -> TokenStream {
  32     symbols::symbols(input.into()).into()
  33 }
  34
  35 /// Creates a struct type `S` that can be used as an index with
  36 /// `IndexVec` and so on.
  37 ///
  38 /// There are two ways of interacting with these indices:
  39 ///
  40 /// - The `From` impls are the preferred way. So you can do
  41 ///   `S::from(v)` with a `usize` or `u32`. And you can convert back
  42 ///   to an integer with `u32::from(s)`.
  43 ///
  44 /// - Alternatively, you can use the methods `S::new(v)` and `s.index()`
  45 ///   to create/return a value.
  46 ///
  47 /// Internally, the index uses a u32, so the index must not exceed
  48 /// `u32::MAX`. You can also customize things like the `Debug` impl,
  49 /// what traits are derived, and so forth via the macro.
  50 #[proc_macro]
  51 #[allow_internal_unstable(step_trait, rustc_attrs, trusted_step)]
  52 pub fn newtype_index(input: TokenStream) -> TokenStream {
  53     newtype::newtype(input)
  54 }
  55
  56 /// Implements the `fluent_messages` macro, which performs compile-time validation of the
  57 /// compiler's Fluent resources (i.e. that the resources parse and don't multiply define the same
  58 /// messages) and generates constants that make using those messages in diagnostics more ergonomic.
  59 ///
  60 /// For example, given the following invocation of the macro..
  61 ///
  62 /// ```ignore (rust)
  63 /// fluent_messages! {
  64 ///     typeck => "./typeck.ftl",
  65 /// }
  66 /// ```
  67 /// ..where `typeck.ftl` has the following contents..
  68 ///
  69 /// ```fluent
  70 /// typeck_field_multiply_specified_in_initializer =
  71 ///     field `{$ident}` specified more than once
  72 ///     .label = used more than once
  73 ///     .label_previous_use = first use of `{$ident}`
  74 /// ```
  75 /// ...then the macro parse the Fluent resource, emitting a diagnostic if it fails to do so, and
  76 /// will generate the following code:
  77 ///
  78 /// ```ignore (rust)
  79 /// pub static DEFAULT_LOCALE_RESOURCES: &'static [&'static str] = &[
  80 ///     include_str!("./typeck.ftl"),
  81 /// ];
  82 ///
  83 /// mod fluent_generated {
  84 ///     mod typeck {
  85 ///         pub const field_multiply_specified_in_initializer: DiagnosticMessage =
  86 ///             DiagnosticMessage::fluent("typeck_field_multiply_specified_in_initializer");
  87 ///         pub const field_multiply_specified_in_initializer_label_previous_use: DiagnosticMessage =
  88 ///             DiagnosticMessage::fluent_attr(
  89 ///                 "typeck_field_multiply_specified_in_initializer",
  90 ///                 "previous_use_label"
  91 ///             );
  92 ///     }
  93 /// }
  94 /// ```
  95 /// When emitting a diagnostic, the generated constants can be used as follows:
  96 ///
  97 /// ```ignore (rust)
  98 /// let mut err = sess.struct_span_err(
  99 ///     span,
 100 ///     fluent::typeck::field_multiply_specified_in_initializer
 101 /// );
 102 /// err.span_default_label(span);
 103 /// err.span_label(
 104 ///     previous_use_span,
 105 ///     fluent::typeck::field_multiply_specified_in_initializer_label_previous_use
 106 /// );
 107 /// err.emit();
 108 /// ```
 109 #[proc_macro]
 110 pub fn fluent_messages(input: TokenStream) -> TokenStream {
 111     diagnostics::fluent_messages(input)
 112 }
 113
 114 decl_derive!([HashStable, attributes(stable_hasher)] => hash_stable::hash_stable_derive);
 115 decl_derive!(
 116     [HashStable_Generic, attributes(stable_hasher)] =>
 117     hash_stable::hash_stable_generic_derive
 118 );
 119
 120 decl_derive!([Decodable] => serialize::decodable_derive);
 121 decl_derive!([Encodable] => serialize::encodable_derive);
 122 decl_derive!([TyDecodable] => serialize::type_decodable_derive);
 123 decl_derive!([TyEncodable] => serialize::type_encodable_derive);
 124 decl_derive!([MetadataDecodable] => serialize::meta_decodable_derive);
 125 decl_derive!([MetadataEncodable] => serialize::meta_encodable_derive);
 126 decl_derive!([TypeFoldable, attributes(type_foldable)] => type_foldable::type_foldable_derive);
 127 decl_derive!([TypeVisitable, attributes(type_visitable)] => type_visitable::type_visitable_derive);
 128 decl_derive!([Lift, attributes(lift)] => lift::lift_derive);
 129 decl_derive!(
 130     [Diagnostic, attributes(
 131         // struct attributes
 132         diag,
 133         help,
 134         note,
 135         warning,
 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         diag,
 150         help,
 151         note,
 152         warning,
 153         // field attributes
 154         skip_arg,
 155         primary_span,
 156         label,
 157         subdiagnostic,
 158         suggestion,
 159         suggestion_short,
 160         suggestion_hidden,
 161         suggestion_verbose)] => diagnostics::lint_diagnostic_derive
 162 );
 163 decl_derive!(
 164     [Subdiagnostic, attributes(
 165         // struct/variant attributes
 166         label,
 167         help,
 168         note,
 169         warning,
 170         suggestion,
 171         suggestion_short,
 172         suggestion_hidden,
 173         suggestion_verbose,
 174         multipart_suggestion,
 175         multipart_suggestion_short,
 176         multipart_suggestion_hidden,
 177         multipart_suggestion_verbose,
 178         // field attributes
 179         skip_arg,
 180         primary_span,
 181         suggestion_part,
 182         applicability)] => diagnostics::session_subdiagnostic_derive
 183 );