src/librustc_hir/target.rs

   1 //! This module implements some validity checks for attributes.
   2 //! In particular it verifies that `#[inline]` and `#[repr]` attributes are
   3 //! attached to items that actually support them and if there are
   4 //! conflicts between multiple such attributes attached to the same
   5 //! item.
   6
   7 use crate::hir;
   8 use crate::{Item, ItemKind, TraitItem, TraitItemKind};
   9
  10 use std::fmt::{self, Display};
  11
  12 #[derive(Copy, Clone, PartialEq)]
  13 pub enum MethodKind {
  14     Trait { body: bool },
  15     Inherent,
  16 }
  17
  18 #[derive(Copy, Clone, PartialEq)]
  19 pub enum Target {
  20     ExternCrate,
  21     Use,
  22     Static,
  23     Const,
  24     Fn,
  25     Closure,
  26     Mod,
  27     ForeignMod,
  28     GlobalAsm,
  29     TyAlias,
  30     OpaqueTy,
  31     Enum,
  32     Struct,
  33     Union,
  34     Trait,
  35     TraitAlias,
  36     Impl,
  37     Expression,
  38     Statement,
  39     AssocConst,
  40     Method(MethodKind),
  41     AssocTy,
  42     ForeignFn,
  43     ForeignStatic,
  44     ForeignTy,
  45 }
  46
  47 impl Display for Target {
  48     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
  49         write!(
  50             f,
  51             "{}",
  52             match *self {
  53                 Target::ExternCrate => "extern crate",
  54                 Target::Use => "use",
  55                 Target::Static => "static item",
  56                 Target::Const => "constant item",
  57                 Target::Fn => "function",
  58                 Target::Closure => "closure",
  59                 Target::Mod => "module",
  60                 Target::ForeignMod => "foreign module",
  61                 Target::GlobalAsm => "global asm",
  62                 Target::TyAlias => "type alias",
  63                 Target::OpaqueTy => "opaque type",
  64                 Target::Enum => "enum",
  65                 Target::Struct => "struct",
  66                 Target::Union => "union",
  67                 Target::Trait => "trait",
  68                 Target::TraitAlias => "trait alias",
  69                 Target::Impl => "item",
  70                 Target::Expression => "expression",
  71                 Target::Statement => "statement",
  72                 Target::AssocConst => "associated const",
  73                 Target::Method(_) => "method",
  74                 Target::AssocTy => "associated type",
  75                 Target::ForeignFn => "foreign function",
  76                 Target::ForeignStatic => "foreign static item",
  77                 Target::ForeignTy => "foreign type",
  78             }
  79         )
  80     }
  81 }
  82
  83 impl Target {
  84     pub fn from_item(item: &Item<'_>) -> Target {
  85         match item.kind {
  86             ItemKind::ExternCrate(..) => Target::ExternCrate,
  87             ItemKind::Use(..) => Target::Use,
  88             ItemKind::Static(..) => Target::Static,
  89             ItemKind::Const(..) => Target::Const,
  90             ItemKind::Fn(..) => Target::Fn,
  91             ItemKind::Mod(..) => Target::Mod,
  92             ItemKind::ForeignMod(..) => Target::ForeignMod,
  93             ItemKind::GlobalAsm(..) => Target::GlobalAsm,
  94             ItemKind::TyAlias(..) => Target::TyAlias,
  95             ItemKind::OpaqueTy(..) => Target::OpaqueTy,
  96             ItemKind::Enum(..) => Target::Enum,
  97             ItemKind::Struct(..) => Target::Struct,
  98             ItemKind::Union(..) => Target::Union,
  99             ItemKind::Trait(..) => Target::Trait,
 100             ItemKind::TraitAlias(..) => Target::TraitAlias,
 101             ItemKind::Impl { .. } => Target::Impl,
 102         }
 103     }
 104
 105     pub fn from_trait_item(trait_item: &TraitItem<'_>) -> Target {
 106         match trait_item.kind {
 107             TraitItemKind::Const(..) => Target::AssocConst,
 108             TraitItemKind::Fn(_, hir::TraitFn::Required(_)) => {
 109                 Target::Method(MethodKind::Trait { body: false })
 110             }
 111             TraitItemKind::Fn(_, hir::TraitFn::Provided(_)) => {
 112                 Target::Method(MethodKind::Trait { body: true })
 113             }
 114             TraitItemKind::Type(..) => Target::AssocTy,
 115         }
 116     }
 117
 118     pub fn from_foreign_item(foreign_item: &hir::ForeignItem<'_>) -> Target {
 119         match foreign_item.kind {
 120             hir::ForeignItemKind::Fn(..) => Target::ForeignFn,
 121             hir::ForeignItemKind::Static(..) => Target::ForeignStatic,
 122             hir::ForeignItemKind::Type => Target::ForeignTy,
 123         }
 124     }
 125 }