5c28cd259a
This makes sure that empty lines in lint examples are preserved. It also fixes the documentation for the invalid_ref lint, which was not shown because of an extra newline before the lint declaration.
61 lines
2.0 KiB
Rust
61 lines
2.0 KiB
Rust
use rustc::lint::*;
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use rustc::ty;
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use rustc::hir::*;
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use utils::{match_def_path, opt_def_id, paths, span_help_and_lint};
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/// **What it does:** Checks for creation of references to zeroed or uninitialized memory.
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///
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/// **Why is this bad?** Creation of null references is undefined behavior.
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///
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/// **Known problems:** None.
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///
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/// **Example:**
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/// ```rust
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/// let bad_ref: &usize = std::mem::zeroed();
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/// ```
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declare_lint! {
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pub INVALID_REF,
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Warn,
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"creation of invalid reference"
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}
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const ZERO_REF_SUMMARY: &str = "reference to zeroed memory";
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const UNINIT_REF_SUMMARY: &str = "reference to uninitialized memory";
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const HELP: &str = "Creation of a null reference is undefined behavior; \
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see https://doc.rust-lang.org/reference/behavior-considered-undefined.html";
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pub struct InvalidRef;
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impl LintPass for InvalidRef {
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fn get_lints(&self) -> LintArray {
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lint_array!(INVALID_REF)
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}
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}
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impl<'a, 'tcx> LateLintPass<'a, 'tcx> for InvalidRef {
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fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr) {
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if_chain! {
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if let ExprCall(ref path, ref args) = expr.node;
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if let ExprPath(ref qpath) = path.node;
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if args.len() == 0;
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if let ty::TyRef(..) = cx.tables.expr_ty(expr).sty;
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if let Some(def_id) = opt_def_id(cx.tables.qpath_def(qpath, path.hir_id));
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then {
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let msg = if match_def_path(cx.tcx, def_id, &paths::MEM_ZEROED) |
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match_def_path(cx.tcx, def_id, &paths::INIT)
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{
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ZERO_REF_SUMMARY
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} else if match_def_path(cx.tcx, def_id, &paths::MEM_UNINIT) |
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match_def_path(cx.tcx, def_id, &paths::UNINIT)
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{
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UNINIT_REF_SUMMARY
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} else {
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return;
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};
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span_help_and_lint(cx, INVALID_REF, expr.span, msg, HELP);
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}
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}
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return;
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}
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}
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