1 use crate::utils::{is_type_diagnostic_item, 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 rustc_span::symbol::sym;
9 use std::path::{Component, Path};
11 declare_clippy_lint! {
12 /// **What it does:*** Checks for [push](https://doc.rust-lang.org/std/path/struct.PathBuf.html#method.push)
13 /// calls on `PathBuf` that can cause overwrites.
15 /// **Why is this bad?** Calling `push` with a root path at the start can overwrite the
16 /// previous defined path.
18 /// **Known problems:** None.
22 /// use std::path::PathBuf;
24 /// let mut x = PathBuf::from("/foo");
26 /// assert_eq!(x, PathBuf::from("/bar"));
31 /// use std::path::PathBuf;
33 /// let mut x = PathBuf::from("/foo");
35 /// assert_eq!(x, PathBuf::from("/foo/bar"));
37 pub PATH_BUF_PUSH_OVERWRITE,
39 "calling `push` with file system root on `PathBuf` can overwrite it"
42 declare_lint_pass!(PathBufPushOverwrite => [PATH_BUF_PUSH_OVERWRITE]);
44 impl<'tcx> LateLintPass<'tcx> for PathBufPushOverwrite {
45 fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) {
47 if let ExprKind::MethodCall(ref path, _, ref args, _) = expr.kind;
48 if path.ident.name == sym!(push);
50 if is_type_diagnostic_item(cx, cx.typeck_results().expr_ty(&args[0]).peel_refs(), sym::PathBuf);
51 if let Some(get_index_arg) = args.get(1);
52 if let ExprKind::Lit(ref lit) = get_index_arg.kind;
53 if let LitKind::Str(ref path_lit, _) = lit.node;
54 if let pushed_path = Path::new(&*path_lit.as_str());
55 if let Some(pushed_path_lit) = pushed_path.to_str();
56 if pushed_path.has_root();
57 if let Some(root) = pushed_path.components().next();
58 if root == Component::RootDir;
62 PATH_BUF_PUSH_OVERWRITE,
64 "calling `push` with '/' or '\\' (file system root) will overwrite the previous path definition",
66 format!("\"{}\"", pushed_path_lit.trim_start_matches(|c| c == '/' || c == '\\')),
67 Applicability::MachineApplicable,