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// Copyright 2015 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
use session::Session;
use syntax::ast;
use syntax::attr::AttrMetaMethods;
use syntax::visit;
use syntax::visit::Visitor;
#[derive(Copy, Clone, PartialEq)]
enum Target {
Fn,
Struct,
Enum,
Other,
}
impl Target {
fn from_item(item: &ast::Item) -> Target {
match item.node {
ast::ItemKind::Fn(..) => Target::Fn,
ast::ItemKind::Struct(..) => Target::Struct,
ast::ItemKind::Enum(..) => Target::Enum,
_ => Target::Other,
}
}
}
struct CheckAttrVisitor<'a> {
sess: &'a Session,
}
impl<'a> CheckAttrVisitor<'a> {
fn check_inline(&self, attr: &ast::Attribute, target: Target) {
if target != Target::Fn {
span_err!(self.sess, attr.span, E0518, "attribute should be applied to function");
}
}
fn check_repr(&self, attr: &ast::Attribute, target: Target) {
let words = match attr.meta_item_list() {
Some(words) => words,
None => {
return;
}
};
for word in words {
let word: &str = &word.name();
let message = match word {
"C" => {
if target != Target::Struct && target != Target::Enum {
"attribute should be applied to struct or enum"
} else {
continue
}
}
"packed" |
"simd" => {
if target != Target::Struct {
"attribute should be applied to struct"
} else {
continue
}
}
"i8" | "u8" | "i16" | "u16" |
"i32" | "u32" | "i64" | "u64" |
"isize" | "usize" => {
if target != Target::Enum {
"attribute should be applied to enum"
} else {
continue
}
}
_ => continue,
};
span_err!(self.sess, attr.span, E0517, "{}", message);
}
}
fn check_attribute(&self, attr: &ast::Attribute, target: Target) {
let name: &str = &attr.name();
match name {
"inline" => self.check_inline(attr, target),
"repr" => self.check_repr(attr, target),
_ => (),
}
}
}
impl<'a> Visitor for CheckAttrVisitor<'a> {
fn visit_item(&mut self, item: &ast::Item) {
let target = Target::from_item(item);
for attr in &item.attrs {
self.check_attribute(attr, target);
}
visit::walk_item(self, item);
}
}
pub fn check_crate(sess: &Session, krate: &ast::Crate) {
visit::walk_crate(&mut CheckAttrVisitor { sess: sess }, krate);
}