74 lines
2.7 KiB
Rust
74 lines
2.7 KiB
Rust
use clippy_utils::diagnostics::span_lint_and_sugg;
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use clippy_utils::ty::is_type_diagnostic_item;
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use if_chain::if_chain;
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use rustc_ast::ast::LitKind;
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use rustc_errors::Applicability;
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use rustc_hir::{Expr, ExprKind};
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use rustc_lint::{LateContext, LateLintPass};
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use rustc_session::{declare_lint_pass, declare_tool_lint};
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use rustc_span::symbol::sym;
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use std::path::{Component, Path};
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declare_clippy_lint! {
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/// ### What it does
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///* Checks for [push](https://doc.rust-lang.org/std/path/struct.PathBuf.html#method.push)
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/// calls on `PathBuf` that can cause overwrites.
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///
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/// ### Why is this bad?
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/// Calling `push` with a root path at the start can overwrite the
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/// previous defined path.
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///
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/// ### Example
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/// ```rust
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/// use std::path::PathBuf;
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///
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/// let mut x = PathBuf::from("/foo");
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/// x.push("/bar");
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/// assert_eq!(x, PathBuf::from("/bar"));
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/// ```
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/// Could be written:
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///
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/// ```rust
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/// use std::path::PathBuf;
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///
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/// let mut x = PathBuf::from("/foo");
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/// x.push("bar");
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/// assert_eq!(x, PathBuf::from("/foo/bar"));
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/// ```
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pub PATH_BUF_PUSH_OVERWRITE,
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nursery,
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"calling `push` with file system root on `PathBuf` can overwrite it"
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}
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declare_lint_pass!(PathBufPushOverwrite => [PATH_BUF_PUSH_OVERWRITE]);
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impl<'tcx> LateLintPass<'tcx> for PathBufPushOverwrite {
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fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) {
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if_chain! {
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if let ExprKind::MethodCall(path, _, args, _) = expr.kind;
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if path.ident.name == sym!(push);
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if args.len() == 2;
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if is_type_diagnostic_item(cx, cx.typeck_results().expr_ty(&args[0]).peel_refs(), sym::PathBuf);
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if let Some(get_index_arg) = args.get(1);
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if let ExprKind::Lit(ref lit) = get_index_arg.kind;
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if let LitKind::Str(ref path_lit, _) = lit.node;
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if let pushed_path = Path::new(&*path_lit.as_str());
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if let Some(pushed_path_lit) = pushed_path.to_str();
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if pushed_path.has_root();
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if let Some(root) = pushed_path.components().next();
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if root == Component::RootDir;
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then {
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span_lint_and_sugg(
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cx,
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PATH_BUF_PUSH_OVERWRITE,
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lit.span,
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"calling `push` with '/' or '\\' (file system root) will overwrite the previous path definition",
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"try",
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format!("\"{}\"", pushed_path_lit.trim_start_matches(|c| c == '/' || c == '\\')),
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Applicability::MachineApplicable,
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);
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}
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}
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}
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}
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