src/attrs.rs

   1 /// checks for attributes
   2
   3 use rustc::plugin::Registry;
   4 use rustc::lint::*;
   5 use syntax::ast::*;
   6 use syntax::ptr::P;
   7 use syntax::codemap::{Span, ExpnInfo};
   8 use syntax::parse::token::InternedString;
   9 use utils::in_macro;
  10
  11 declare_lint! { pub INLINE_ALWAYS, Warn,
  12     "#[inline(always)] is usually a bad idea."}
  13
  14
  15 #[derive(Copy,Clone)]
  16 pub struct AttrPass;
  17
  18 impl LintPass for AttrPass {
  19     fn get_lints(&self) -> LintArray {
  20         lint_array!(INLINE_ALWAYS)
  21     }
  22
  23     fn check_item(&mut self, cx: &Context, item: &Item) {
  24                 cx.sess().codemap().with_expn_info(item.span.expn_id,
  25                         |info| check_attrs(cx, info, &item.ident, &item.attrs))
  26         }
  27
  28     fn check_impl_item(&mut self, cx: &Context, item: &ImplItem) {
  29                 cx.sess().codemap().with_expn_info(item.span.expn_id,
  30                         |info| check_attrs(cx, info, &item.ident, &item.attrs))
  31         }
  32
  33         fn check_trait_item(&mut self, cx: &Context, item: &TraitItem) {
  34                 cx.sess().codemap().with_expn_info(item.span.expn_id,
  35                         |info| check_attrs(cx, info, &item.ident, &item.attrs))
  36         }
  37 }
  38
  39 fn check_attrs(cx: &Context, info: Option<&ExpnInfo>, ident: &Ident,
  40                 attrs: &[Attribute]) {
  41         if in_macro(cx, info) { return; }
  42
  43         for attr in attrs {
  44                 if let MetaList(ref inline, ref values) = attr.node.value.node {
  45                         if values.len() != 1 || inline != &"inline" { continue; }
  46                         if let MetaWord(ref always) = values[0].node {
  47                                 if always != &"always" { continue; }
  48                                 cx.span_lint(INLINE_ALWAYS, attr.span, &format!(
  49                                         "You have declared #[inline(always)] on {}. This \
  50                                         is usually a bad idea. Are you sure?",
  51                                         ident.as_str()));
  52                         }
  53                 }
  54         }
  55 }