use crate::consts::{constant, Constant};
-use crate::utils::paths;
-use crate::utils::{is_direct_expn_of, is_expn_of, match_function_call, snippet_opt, span_help_and_lint};
+use crate::utils::{is_direct_expn_of, is_expn_of, match_panic_call, snippet_opt, span_lint_and_help};
use if_chain::if_chain;
-use rustc::lint::{LateContext, LateLintPass};
-use rustc_hir::*;
+use rustc_hir::{Expr, ExprKind, UnOp};
+use rustc_lint::{LateContext, LateLintPass};
use rustc_session::{declare_lint_pass, declare_tool_lint};
-use syntax::ast::LitKind;
declare_clippy_lint! {
/// **What it does:** Checks for `assert!(true)` and `assert!(false)` calls.
///
/// **Why is this bad?** Will be optimized out by the compiler or should probably be replaced by a
- /// panic!() or unreachable!()
+ /// `panic!()` or `unreachable!()`
///
/// **Known problems:** None
///
/// **Example:**
/// ```rust,ignore
/// assert!(false)
- /// // or
/// assert!(true)
- /// // or
/// const B: bool = false;
/// assert!(B)
/// ```
declare_lint_pass!(AssertionsOnConstants => [ASSERTIONS_ON_CONSTANTS]);
-impl<'a, 'tcx> LateLintPass<'a, 'tcx> for AssertionsOnConstants {
- fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, e: &'tcx Expr<'_>) {
- let lint_true = || {
- span_help_and_lint(
+impl<'tcx> LateLintPass<'tcx> for AssertionsOnConstants {
+ fn check_expr(&mut self, cx: &LateContext<'tcx>, e: &'tcx Expr<'_>) {
+ let lint_true = |is_debug: bool| {
+ span_lint_and_help(
cx,
ASSERTIONS_ON_CONSTANTS,
e.span,
- "`assert!(true)` will be optimized out by the compiler",
+ if is_debug {
+ "`debug_assert!(true)` will be optimized out by the compiler"
+ } else {
+ "`assert!(true)` will be optimized out by the compiler"
+ },
+ None,
"remove it",
);
};
let lint_false_without_message = || {
- span_help_and_lint(
+ span_lint_and_help(
cx,
ASSERTIONS_ON_CONSTANTS,
e.span,
"`assert!(false)` should probably be replaced",
+ None,
"use `panic!()` or `unreachable!()`",
);
};
let lint_false_with_message = |panic_message: String| {
- span_help_and_lint(
+ span_lint_and_help(
cx,
ASSERTIONS_ON_CONSTANTS,
e.span,
&format!("`assert!(false, {})` should probably be replaced", panic_message),
+ None,
&format!("use `panic!({})` or `unreachable!({})`", panic_message, panic_message),
)
};
}
if_chain! {
if let ExprKind::Unary(_, ref lit) = e.kind;
- if let Some((Constant::Bool(is_true), _)) = constant(cx, cx.tables, lit);
+ if let Some((Constant::Bool(is_true), _)) = constant(cx, cx.typeck_results(), lit);
if is_true;
then {
- lint_true();
+ lint_true(true);
}
};
} else if let Some(assert_span) = is_direct_expn_of(e.span, "assert") {
match assert_match {
// matched assert but not message
AssertKind::WithoutMessage(false) => lint_false_without_message(),
- AssertKind::WithoutMessage(true) | AssertKind::WithMessage(_, true) => lint_true(),
+ AssertKind::WithoutMessage(true) | AssertKind::WithMessage(_, true) => lint_true(false),
AssertKind::WithMessage(panic_message, false) => lint_false_with_message(panic_message),
};
}
/// Check if the expression matches
///
/// ```rust,ignore
-/// match { let _t = !c; _t } {
-/// true => {
-/// {
-/// ::std::rt::begin_panic(message, _)
-/// }
-/// }
-/// _ => { }
-/// };
+/// if !c {
+/// {
+/// ::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> {
+fn match_assert_with_message<'tcx>(cx: &LateContext<'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;
+ if let ExprKind::If(ref cond, ref then, _) = expr.kind;
+ if let ExprKind::Unary(UnOp::Not, ref expr) = cond.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 let Some((Constant::Bool(is_true), _)) = constant(cx, cx.typeck_results(), expr);
+ // block
+ if let ExprKind::Block(ref block, _) = then.kind;
if block.stmts.is_empty();
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;
+ // inner block is optional. unwrap it if it exists, or use the expression as is otherwise.
+ if let Some(begin_panic_call) = match block_expr.kind {
+ ExprKind::Block(ref inner_block, _) => &inner_block.expr,
+ _ => &block.expr,
+ };
// function call
- if let Some(args) = match_function_call(cx, begin_panic_call, &paths::BEGIN_PANIC);
+ if let Some(args) = match_panic_call(cx, begin_panic_call);
if args.len() == 1;
// bind the second argument of the `assert!` macro if it exists
if let panic_message = snippet_opt(cx, args[0].span);