+ if let Some(assert_match) = match_assert_with_message(&cx, e) {
+ match assert_match {
+ // matched assert but not message
+ AssertKind::WithoutMessage(false) => lint_false_without_message(),
+ AssertKind::WithoutMessage(true) | AssertKind::WithMessage(_, true) => lint_true(),
+ AssertKind::WithMessage(panic_message, false) => lint_false_with_message(panic_message),
+ };
+ }
+ }
+ }
+}
+
+/// Result of calling `match_assert_with_message`.
+enum AssertKind {
+ WithMessage(String, bool),
+ WithoutMessage(bool),
+}
+
+/// Check if the expression matches
+///
+/// ```rust,ignore
+/// match { let _t = !c; _t } {
+/// true => {
+/// {
+/// ::std::rt::begin_panic(message, _)
+/// }
+/// }
+/// _ => { }
+/// };
+/// ```
+///
+/// where `message` is any expression and `c` is a constant bool.
+fn match_assert_with_message<'a, 'tcx>(cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr) -> Option<AssertKind> {
+ if_chain! {
+ if let ExprKind::Match(ref expr, ref arms, _) = expr.kind;
+ // matches { let _t = expr; _t }
+ if let ExprKind::DropTemps(ref expr) = expr.kind;
+ if let ExprKind::Unary(UnOp::UnNot, ref expr) = expr.kind;
+ // bind the first argument of the `assert!` macro
+ if let Some((Constant::Bool(is_true), _)) = constant(cx, cx.tables, expr);
+ // arm 1 pattern
+ if let PatKind::Lit(ref lit_expr) = arms[0].pat.kind;
+ if let ExprKind::Lit(ref lit) = lit_expr.kind;
+ if let LitKind::Bool(true) = lit.node;
+ // arm 1 block
+ if let ExprKind::Block(ref block, _) = arms[0].body.kind;
+ if block.stmts.len() == 0;
+ if let Some(block_expr) = &block.expr;
+ if let ExprKind::Block(ref inner_block, _) = block_expr.kind;
+ if let Some(begin_panic_call) = &inner_block.expr;
+ // function call
+ if let Some(args) = match_function_call(cx, begin_panic_call, &paths::BEGIN_PANIC);
+ if args.len() == 2;
+ // bind the second argument of the `assert!` macro if it exists
+ if let panic_message = snippet_opt(cx, args[0].span);
+ // second argument of begin_panic is irrelevant
+ // as is the second match arm
+ then {
+ // an empty message occurs when it was generated by the macro
+ // (and not passed by the user)
+ return panic_message
+ .filter(|msg| !msg.is_empty())
+ .map(|msg| AssertKind::WithMessage(msg, is_true))
+ .or(Some(AssertKind::WithoutMessage(is_true)));