2019-10-05 14:45:02 +00:00
|
|
|
use crate::consts::{constant, Constant};
|
2021-03-25 18:29:11 +00:00
|
|
|
use clippy_utils::diagnostics::span_lint_and_help;
|
|
|
|
use clippy_utils::source::snippet_opt;
|
|
|
|
use clippy_utils::{is_direct_expn_of, is_expn_of, match_panic_call};
|
2019-10-05 14:45:02 +00:00
|
|
|
use if_chain::if_chain;
|
2021-01-01 18:38:11 +00:00
|
|
|
use rustc_hir::{Expr, ExprKind, UnOp};
|
2020-01-12 06:08:41 +00:00
|
|
|
use rustc_lint::{LateContext, LateLintPass};
|
2020-01-11 11:37:08 +00:00
|
|
|
use rustc_session::{declare_lint_pass, declare_tool_lint};
|
2018-12-25 22:29:03 +00:00
|
|
|
|
|
|
|
declare_clippy_lint! {
|
2019-01-31 01:15:29 +00:00
|
|
|
/// **What it does:** Checks for `assert!(true)` and `assert!(false)` calls.
|
2019-03-05 16:50:33 +00:00
|
|
|
///
|
|
|
|
/// **Why is this bad?** Will be optimized out by the compiler or should probably be replaced by a
|
2020-03-18 01:50:39 +00:00
|
|
|
/// `panic!()` or `unreachable!()`
|
2019-03-05 16:50:33 +00:00
|
|
|
///
|
|
|
|
/// **Known problems:** None
|
|
|
|
///
|
|
|
|
/// **Example:**
|
2019-03-10 22:01:56 +00:00
|
|
|
/// ```rust,ignore
|
2019-01-31 01:15:29 +00:00
|
|
|
/// assert!(false)
|
|
|
|
/// assert!(true)
|
2019-03-05 16:50:33 +00:00
|
|
|
/// const B: bool = false;
|
2019-01-31 01:15:29 +00:00
|
|
|
/// assert!(B)
|
2019-03-05 16:50:33 +00:00
|
|
|
/// ```
|
2019-01-09 10:38:38 +00:00
|
|
|
pub ASSERTIONS_ON_CONSTANTS,
|
|
|
|
style,
|
2019-03-10 17:19:47 +00:00
|
|
|
"`assert!(true)` / `assert!(false)` will be optimized out by the compiler, and should probably be replaced by a `panic!()` or `unreachable!()`"
|
2018-12-25 22:29:03 +00:00
|
|
|
}
|
|
|
|
|
2019-04-08 20:43:55 +00:00
|
|
|
declare_lint_pass!(AssertionsOnConstants => [ASSERTIONS_ON_CONSTANTS]);
|
2018-12-25 22:29:03 +00:00
|
|
|
|
2020-06-25 20:41:36 +00:00
|
|
|
impl<'tcx> LateLintPass<'tcx> for AssertionsOnConstants {
|
|
|
|
fn check_expr(&mut self, cx: &LateContext<'tcx>, e: &'tcx Expr<'_>) {
|
2020-01-20 02:52:58 +00:00
|
|
|
let lint_true = |is_debug: bool| {
|
2020-01-27 01:56:22 +00:00
|
|
|
span_lint_and_help(
|
2019-10-07 20:08:00 +00:00
|
|
|
cx,
|
|
|
|
ASSERTIONS_ON_CONSTANTS,
|
|
|
|
e.span,
|
2020-01-20 02:52:58 +00:00
|
|
|
if is_debug {
|
|
|
|
"`debug_assert!(true)` will be optimized out by the compiler"
|
|
|
|
} else {
|
|
|
|
"`assert!(true)` will be optimized out by the compiler"
|
|
|
|
},
|
2020-04-18 10:28:29 +00:00
|
|
|
None,
|
2019-10-07 20:08:00 +00:00
|
|
|
"remove it",
|
|
|
|
);
|
|
|
|
};
|
|
|
|
let lint_false_without_message = || {
|
2020-01-27 01:56:22 +00:00
|
|
|
span_lint_and_help(
|
2019-10-07 20:08:00 +00:00
|
|
|
cx,
|
|
|
|
ASSERTIONS_ON_CONSTANTS,
|
|
|
|
e.span,
|
|
|
|
"`assert!(false)` should probably be replaced",
|
2020-04-18 10:28:29 +00:00
|
|
|
None,
|
2019-10-07 20:08:00 +00:00
|
|
|
"use `panic!()` or `unreachable!()`",
|
|
|
|
);
|
2019-08-17 18:46:44 +00:00
|
|
|
};
|
2019-10-07 20:08:00 +00:00
|
|
|
let lint_false_with_message = |panic_message: String| {
|
2020-01-27 01:56:22 +00:00
|
|
|
span_lint_and_help(
|
2019-10-07 20:08:00 +00:00
|
|
|
cx,
|
|
|
|
ASSERTIONS_ON_CONSTANTS,
|
|
|
|
e.span,
|
|
|
|
&format!("`assert!(false, {})` should probably be replaced", panic_message),
|
2020-04-18 10:28:29 +00:00
|
|
|
None,
|
2019-10-07 20:08:00 +00:00
|
|
|
&format!("use `panic!({})` or `unreachable!({})`", panic_message, panic_message),
|
|
|
|
)
|
|
|
|
};
|
|
|
|
|
2019-08-17 18:46:44 +00:00
|
|
|
if let Some(debug_assert_span) = is_expn_of(e.span, "debug_assert") {
|
2019-08-19 16:30:32 +00:00
|
|
|
if debug_assert_span.from_expansion() {
|
2019-08-17 18:46:44 +00:00
|
|
|
return;
|
|
|
|
}
|
2019-10-07 20:08:00 +00:00
|
|
|
if_chain! {
|
2021-04-08 15:50:13 +00:00
|
|
|
if let ExprKind::Unary(_, lit) = e.kind;
|
2020-07-17 08:47:04 +00:00
|
|
|
if let Some((Constant::Bool(is_true), _)) = constant(cx, cx.typeck_results(), lit);
|
2019-10-07 20:08:00 +00:00
|
|
|
if is_true;
|
|
|
|
then {
|
2020-01-20 02:52:58 +00:00
|
|
|
lint_true(true);
|
2019-10-07 20:08:00 +00:00
|
|
|
}
|
|
|
|
};
|
2019-08-17 18:46:44 +00:00
|
|
|
} else if let Some(assert_span) = is_direct_expn_of(e.span, "assert") {
|
2019-08-19 16:30:32 +00:00
|
|
|
if assert_span.from_expansion() {
|
2019-08-17 18:46:44 +00:00
|
|
|
return;
|
|
|
|
}
|
2021-04-08 15:50:13 +00:00
|
|
|
if let Some(assert_match) = match_assert_with_message(cx, e) {
|
2019-10-07 20:08:00 +00:00
|
|
|
match assert_match {
|
|
|
|
// matched assert but not message
|
|
|
|
AssertKind::WithoutMessage(false) => lint_false_without_message(),
|
2020-01-20 02:52:58 +00:00
|
|
|
AssertKind::WithoutMessage(true) | AssertKind::WithMessage(_, true) => lint_true(false),
|
2019-10-07 20:08:00 +00:00
|
|
|
AssertKind::WithMessage(panic_message, false) => lint_false_with_message(panic_message),
|
|
|
|
};
|
2019-10-05 14:45:02 +00:00
|
|
|
}
|
|
|
|
}
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
2019-10-07 20:08:00 +00:00
|
|
|
/// Result of calling `match_assert_with_message`.
|
|
|
|
enum AssertKind {
|
|
|
|
WithMessage(String, bool),
|
|
|
|
WithoutMessage(bool),
|
|
|
|
}
|
|
|
|
|
2019-10-06 18:10:30 +00:00
|
|
|
/// Check if the expression matches
|
|
|
|
///
|
|
|
|
/// ```rust,ignore
|
2021-01-01 18:38:11 +00:00
|
|
|
/// if !c {
|
|
|
|
/// {
|
|
|
|
/// ::std::rt::begin_panic(message, _)
|
|
|
|
/// }
|
|
|
|
/// }
|
2019-10-06 18:10:30 +00:00
|
|
|
/// ```
|
|
|
|
///
|
2019-10-07 20:08:00 +00:00
|
|
|
/// where `message` is any expression and `c` is a constant bool.
|
2020-06-25 20:41:36 +00:00
|
|
|
fn match_assert_with_message<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) -> Option<AssertKind> {
|
2019-10-05 14:45:02 +00:00
|
|
|
if_chain! {
|
2021-04-08 15:50:13 +00:00
|
|
|
if let ExprKind::If(cond, then, _) = expr.kind;
|
|
|
|
if let ExprKind::Unary(UnOp::Not, expr) = cond.kind;
|
2019-10-06 18:10:30 +00:00
|
|
|
// bind the first argument of the `assert!` macro
|
2020-07-17 08:47:04 +00:00
|
|
|
if let Some((Constant::Bool(is_true), _)) = constant(cx, cx.typeck_results(), expr);
|
2021-01-01 18:38:11 +00:00
|
|
|
// block
|
2021-04-08 15:50:13 +00:00
|
|
|
if let ExprKind::Block(block, _) = then.kind;
|
2019-12-27 07:12:26 +00:00
|
|
|
if block.stmts.is_empty();
|
2019-10-06 18:10:30 +00:00
|
|
|
if let Some(block_expr) = &block.expr;
|
2020-11-23 12:51:04 +00:00
|
|
|
// inner block is optional. unwrap it if it exists, or use the expression as is otherwise.
|
2020-11-19 18:47:25 +00:00
|
|
|
if let Some(begin_panic_call) = match block_expr.kind {
|
2021-04-08 15:50:13 +00:00
|
|
|
ExprKind::Block(inner_block, _) => &inner_block.expr,
|
2020-11-19 18:47:25 +00:00
|
|
|
_ => &block.expr,
|
|
|
|
};
|
2019-10-05 14:45:02 +00:00
|
|
|
// function call
|
2021-04-22 09:31:13 +00:00
|
|
|
if let Some(arg) = match_panic_call(cx, begin_panic_call);
|
2019-10-07 20:08:00 +00:00
|
|
|
// bind the second argument of the `assert!` macro if it exists
|
2021-04-22 09:31:13 +00:00
|
|
|
if let panic_message = snippet_opt(cx, arg.span);
|
2019-10-06 18:10:30 +00:00
|
|
|
// second argument of begin_panic is irrelevant
|
|
|
|
// as is the second match arm
|
2019-10-05 14:45:02 +00:00
|
|
|
then {
|
2019-10-07 20:08:00 +00:00
|
|
|
// 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)));
|
2018-12-25 22:29:03 +00:00
|
|
|
}
|
|
|
|
}
|
2019-10-06 18:10:30 +00:00
|
|
|
None
|
|
|
|
}
|