1 use crate::utils::{match_type, paths, span_lint_and_sugg};
2 use if_chain::if_chain;
3 use rustc_ast::ast::LitKind;
4 use rustc_errors::Applicability;
5 use rustc_hir::{Expr, ExprKind};
6 use rustc_lint::{LateContext, LateLintPass};
7 use rustc_session::{declare_lint_pass, declare_tool_lint};
8 use std::path::{Component, Path};
10 declare_clippy_lint! {
11 /// **What it does:*** Checks for [push](https://doc.rust-lang.org/std/path/struct.PathBuf.html#method.push)
12 /// calls on `PathBuf` that can cause overwrites.
14 /// **Why is this bad?** Calling `push` with a root path at the start can overwrite the
15 /// previous defined path.
17 /// **Known problems:** None.
21 /// use std::path::PathBuf;
23 /// let mut x = PathBuf::from("/foo");
25 /// assert_eq!(x, PathBuf::from("/bar"));
30 /// use std::path::PathBuf;
32 /// let mut x = PathBuf::from("/foo");
34 /// assert_eq!(x, PathBuf::from("/foo/bar"));
36 pub PATH_BUF_PUSH_OVERWRITE,
38 "calling `push` with file system root on `PathBuf` can overwrite it"
41 declare_lint_pass!(PathBufPushOverwrite => [PATH_BUF_PUSH_OVERWRITE]);
43 impl<'tcx> LateLintPass<'tcx> for PathBufPushOverwrite {
44 fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) {
46 if let ExprKind::MethodCall(ref path, _, ref args, _) = expr.kind;
47 if path.ident.name == sym!(push);
49 if match_type(cx, cx.typeck_results().expr_ty(&args[0]).peel_refs(), &paths::PATH_BUF);
50 if let Some(get_index_arg) = args.get(1);
51 if let ExprKind::Lit(ref lit) = get_index_arg.kind;
52 if let LitKind::Str(ref path_lit, _) = lit.node;
53 if let pushed_path = Path::new(&*path_lit.as_str());
54 if let Some(pushed_path_lit) = pushed_path.to_str();
55 if pushed_path.has_root();
56 if let Some(root) = pushed_path.components().next();
57 if root == Component::RootDir;
61 PATH_BUF_PUSH_OVERWRITE,
63 "calling `push` with '/' or '\\' (file system root) will overwrite the previous path definition",
65 format!("\"{}\"", pushed_path_lit.trim_start_matches(|c| c == '/' || c == '\\')),
66 Applicability::MachineApplicable,