75 lines
2.8 KiB
Rust
75 lines
2.8 KiB
Rust
use if_chain::if_chain;
|
|
use rustc::hir::{Expr, ExprKind};
|
|
use rustc::lint::{LateContext, LateLintPass, LintArray, LintPass};
|
|
use rustc::{declare_lint_pass, declare_tool_lint};
|
|
use syntax_pos::Span;
|
|
|
|
use crate::consts::{constant, Constant};
|
|
use crate::utils::{in_macro_or_desugar, is_direct_expn_of, span_help_and_lint};
|
|
|
|
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!()
|
|
///
|
|
/// **Known problems:** None
|
|
///
|
|
/// **Example:**
|
|
/// ```rust,ignore
|
|
/// assert!(false)
|
|
/// // or
|
|
/// assert!(true)
|
|
/// // or
|
|
/// const B: bool = false;
|
|
/// assert!(B)
|
|
/// ```
|
|
pub ASSERTIONS_ON_CONSTANTS,
|
|
style,
|
|
"`assert!(true)` / `assert!(false)` will be optimized out by the compiler, and should probably be replaced by a `panic!()` or `unreachable!()`"
|
|
}
|
|
|
|
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 mut is_debug_assert = false;
|
|
let debug_assert_not_in_macro_or_desugar = |span: Span| {
|
|
is_debug_assert = true;
|
|
// Check that `debug_assert!` itself is not inside a macro
|
|
!in_macro_or_desugar(span)
|
|
};
|
|
if_chain! {
|
|
if let Some(assert_span) = is_direct_expn_of(e.span, "assert");
|
|
if !in_macro_or_desugar(assert_span)
|
|
|| is_direct_expn_of(assert_span, "debug_assert")
|
|
.map_or(false, debug_assert_not_in_macro_or_desugar);
|
|
if let ExprKind::Unary(_, ref lit) = e.node;
|
|
if let Some(bool_const) = constant(cx, cx.tables, lit);
|
|
then {
|
|
match bool_const.0 {
|
|
Constant::Bool(true) => {
|
|
span_help_and_lint(
|
|
cx,
|
|
ASSERTIONS_ON_CONSTANTS,
|
|
e.span,
|
|
"`assert!(true)` will be optimized out by the compiler",
|
|
"remove it"
|
|
);
|
|
},
|
|
Constant::Bool(false) if !is_debug_assert => {
|
|
span_help_and_lint(
|
|
cx,
|
|
ASSERTIONS_ON_CONSTANTS,
|
|
e.span,
|
|
"`assert!(false)` should probably be replaced",
|
|
"use `panic!()` or `unreachable!()`"
|
|
);
|
|
},
|
|
_ => (),
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|