rustc: move rustc_front to rustc::hir.

src/librustc/hir/check_attr.rs

@@ -0,0 +1,110 @@
+// 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, 'v> Visitor<'v> 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);
+}