rust/clippy_lints/src/unsafe_removed_from_name.rs
2018-03-28 15:24:26 +02:00

81 lines
2.2 KiB
Rust

use rustc::lint::*;
use syntax::ast::*;
use syntax::codemap::Span;
use syntax::symbol::InternedString;
use utils::span_lint;
/// **What it does:** Checks for imports that remove "unsafe" from an item's
/// name.
///
/// **Why is this bad?** Renaming makes it less clear which traits and
/// structures are unsafe.
///
/// **Known problems:** None.
///
/// **Example:**
/// ```rust,ignore
/// use std::cell::{UnsafeCell as TotallySafeCell};
///
/// extern crate crossbeam;
/// use crossbeam::{spawn_unsafe as spawn};
/// ```
declare_clippy_lint! {
pub UNSAFE_REMOVED_FROM_NAME,
style,
"`unsafe` removed from API names on import"
}
pub struct UnsafeNameRemoval;
impl LintPass for UnsafeNameRemoval {
fn get_lints(&self) -> LintArray {
lint_array!(UNSAFE_REMOVED_FROM_NAME)
}
}
impl EarlyLintPass for UnsafeNameRemoval {
fn check_item(&mut self, cx: &EarlyContext, item: &Item) {
if let ItemKind::Use(ref use_tree) = item.node {
check_use_tree(use_tree, cx, &item.span);
}
}
}
fn check_use_tree(use_tree: &UseTree, cx: &EarlyContext, span: &Span) {
match use_tree.kind {
UseTreeKind::Simple(Some(new_name)) => {
let old_name = use_tree
.prefix
.segments
.last()
.expect("use paths cannot be empty")
.identifier;
unsafe_to_safe_check(old_name, new_name, cx, span);
}
UseTreeKind::Simple(None) |
UseTreeKind::Glob => {},
UseTreeKind::Nested(ref nested_use_tree) => {
for &(ref use_tree, _) in nested_use_tree {
check_use_tree(use_tree, cx, span);
}
}
}
}
fn unsafe_to_safe_check(old_name: Ident, new_name: Ident, cx: &EarlyContext, span: &Span) {
let old_str = old_name.name.as_str();
let new_str = new_name.name.as_str();
if contains_unsafe(&old_str) && !contains_unsafe(&new_str) {
span_lint(
cx,
UNSAFE_REMOVED_FROM_NAME,
*span,
&format!("removed \"unsafe\" from the name of `{}` in use as `{}`", old_str, new_str),
);
}
}
fn contains_unsafe(name: &InternedString) -> bool {
name.contains("Unsafe") || name.contains("unsafe")
}