| use crate::utils::{match_type, paths, span_lint_and_sugg, walk_ptrs_ty}; |
| use if_chain::if_chain; |
| use rustc::hir::*; |
| use rustc::lint::{LateContext, LateLintPass, LintArray, LintPass}; |
| use rustc::{declare_lint_pass, declare_tool_lint}; |
| use rustc_errors::Applicability; |
| use std::path::{Component, Path}; |
| use syntax::ast::LitKind; |
| |
| declare_clippy_lint! { |
| /// **What it does:*** Checks for [push](https://doc.rust-lang.org/std/path/struct.PathBuf.html#method.push) |
| /// calls on `PathBuf` that can cause overwrites. |
| /// |
| /// **Why is this bad?** Calling `push` with a root path at the start can overwrite the |
| /// previous defined path. |
| /// |
| /// **Known problems:** None. |
| /// |
| /// **Example:** |
| /// ```rust |
| /// use std::path::PathBuf; |
| /// |
| /// let mut x = PathBuf::from("/foo"); |
| /// x.push("/bar"); |
| /// assert_eq!(x, PathBuf::from("/bar")); |
| /// ``` |
| /// Could be written: |
| /// |
| /// ```rust |
| /// use std::path::PathBuf; |
| /// |
| /// let mut x = PathBuf::from("/foo"); |
| /// x.push("bar"); |
| /// assert_eq!(x, PathBuf::from("/foo/bar")); |
| /// ``` |
| pub PATH_BUF_PUSH_OVERWRITE, |
| nursery, |
| "calling `push` with file system root on `PathBuf` can overwrite it" |
| } |
| |
| declare_lint_pass!(PathBufPushOverwrite => [PATH_BUF_PUSH_OVERWRITE]); |
| |
| impl<'a, 'tcx> LateLintPass<'a, 'tcx> for PathBufPushOverwrite { |
| fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr) { |
| if_chain! { |
| if let ExprKind::MethodCall(ref path, _, ref args) = expr.kind; |
| if path.ident.name == sym!(push); |
| if args.len() == 2; |
| if match_type(cx, walk_ptrs_ty(cx.tables.expr_ty(&args[0])), &paths::PATH_BUF); |
| if let Some(get_index_arg) = args.get(1); |
| if let ExprKind::Lit(ref lit) = get_index_arg.kind; |
| if let LitKind::Str(ref path_lit, _) = lit.node; |
| if let pushed_path = Path::new(&path_lit.as_str()); |
| if let Some(pushed_path_lit) = pushed_path.to_str(); |
| if pushed_path.has_root(); |
| if let Some(root) = pushed_path.components().next(); |
| if root == Component::RootDir; |
| then { |
| span_lint_and_sugg( |
| cx, |
| PATH_BUF_PUSH_OVERWRITE, |
| lit.span, |
| "Calling `push` with '/' or '\\' (file system root) will overwrite the previous path definition", |
| "try", |
| format!("\"{}\"", pushed_path_lit.trim_start_matches(|c| c == '/' || c == '\\')), |
| Applicability::MachineApplicable, |
| ); |
| } |
| } |
| } |
| } |