| use crate::utils::{match_def_path, paths, span_help_and_lint}; |
| use if_chain::if_chain; |
| use rustc::hir::*; |
| use rustc::lint::{LateContext, LateLintPass, LintArray, LintPass}; |
| use rustc::ty; |
| use rustc::{declare_lint_pass, declare_tool_lint}; |
| |
| declare_clippy_lint! { |
| /// **What it does:** Checks for creation of references to zeroed or uninitialized memory. |
| /// |
| /// **Why is this bad?** Creation of null references is undefined behavior. |
| /// |
| /// **Known problems:** None. |
| /// |
| /// **Example:** |
| /// ```no_run |
| /// let bad_ref: &usize = unsafe { std::mem::zeroed() }; |
| /// ``` |
| pub INVALID_REF, |
| correctness, |
| "creation of invalid reference" |
| } |
| |
| const ZERO_REF_SUMMARY: &str = "reference to zeroed memory"; |
| const UNINIT_REF_SUMMARY: &str = "reference to uninitialized memory"; |
| const HELP: &str = "Creation of a null reference is undefined behavior; \ |
| see https://doc.rust-lang.org/reference/behavior-considered-undefined.html"; |
| |
| declare_lint_pass!(InvalidRef => [INVALID_REF]); |
| |
| impl<'a, 'tcx> LateLintPass<'a, 'tcx> for InvalidRef { |
| fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr) { |
| if_chain! { |
| if let ExprKind::Call(ref path, ref args) = expr.node; |
| if let ExprKind::Path(ref qpath) = path.node; |
| if args.len() == 0; |
| if let ty::Ref(..) = cx.tables.expr_ty(expr).sty; |
| if let Some(def_id) = cx.tables.qpath_res(qpath, path.hir_id).opt_def_id(); |
| then { |
| let msg = if match_def_path(cx, def_id, &paths::MEM_ZEROED) | |
| match_def_path(cx, def_id, &paths::INIT) |
| { |
| ZERO_REF_SUMMARY |
| } else if match_def_path(cx, def_id, &paths::MEM_UNINIT) | |
| match_def_path(cx, def_id, &paths::UNINIT) |
| { |
| UNINIT_REF_SUMMARY |
| } else { |
| return; |
| }; |
| span_help_and_lint(cx, INVALID_REF, expr.span, msg, HELP); |
| } |
| } |
| } |
| } |