83 lines
2.9 KiB
Rust
83 lines
2.9 KiB
Rust
use clippy_utils::diagnostics::span_lint_and_then;
|
|
use clippy_utils::ty::is_type_diagnostic_item;
|
|
use clippy_utils::{find_macro_calls, is_expn_of, return_ty};
|
|
use rustc_hir as hir;
|
|
use rustc_hir::intravisit::FnKind;
|
|
use rustc_lint::{LateContext, LateLintPass};
|
|
use rustc_session::{declare_lint_pass, declare_tool_lint};
|
|
use rustc_span::{sym, Span};
|
|
|
|
declare_clippy_lint! {
|
|
/// **What it does:** Checks for usage of `panic!`, `unimplemented!`, `todo!`, `unreachable!` or assertions in a function of type result.
|
|
///
|
|
/// **Why is this bad?** For some codebases, it is desirable for functions of type result to return an error instead of crashing. Hence panicking macros should be avoided.
|
|
///
|
|
/// **Known problems:** Functions called from a function returning a `Result` may invoke a panicking macro. This is not checked.
|
|
///
|
|
/// **Example:**
|
|
///
|
|
/// ```rust
|
|
/// fn result_with_panic() -> Result<bool, String>
|
|
/// {
|
|
/// panic!("error");
|
|
/// }
|
|
/// ```
|
|
/// Use instead:
|
|
/// ```rust
|
|
/// fn result_without_panic() -> Result<bool, String> {
|
|
/// Err(String::from("error"))
|
|
/// }
|
|
/// ```
|
|
pub PANIC_IN_RESULT_FN,
|
|
restriction,
|
|
"functions of type `Result<..>` that contain `panic!()`, `todo!()`, `unreachable()`, `unimplemented()` or assertion"
|
|
}
|
|
|
|
declare_lint_pass!(PanicInResultFn => [PANIC_IN_RESULT_FN]);
|
|
|
|
impl<'tcx> LateLintPass<'tcx> for PanicInResultFn {
|
|
fn check_fn(
|
|
&mut self,
|
|
cx: &LateContext<'tcx>,
|
|
fn_kind: FnKind<'tcx>,
|
|
_: &'tcx hir::FnDecl<'tcx>,
|
|
body: &'tcx hir::Body<'tcx>,
|
|
span: Span,
|
|
hir_id: hir::HirId,
|
|
) {
|
|
if !matches!(fn_kind, FnKind::Closure) && is_type_diagnostic_item(cx, return_ty(cx, hir_id), sym::result_type) {
|
|
lint_impl_body(cx, span, body);
|
|
}
|
|
}
|
|
}
|
|
|
|
fn lint_impl_body<'tcx>(cx: &LateContext<'tcx>, impl_span: Span, body: &'tcx hir::Body<'tcx>) {
|
|
let mut panics = find_macro_calls(
|
|
&[
|
|
"unimplemented",
|
|
"unreachable",
|
|
"panic",
|
|
"todo",
|
|
"assert",
|
|
"assert_eq",
|
|
"assert_ne",
|
|
],
|
|
body,
|
|
);
|
|
panics.retain(|span| is_expn_of(*span, "debug_assert").is_none());
|
|
if !panics.is_empty() {
|
|
span_lint_and_then(
|
|
cx,
|
|
PANIC_IN_RESULT_FN,
|
|
impl_span,
|
|
"used `unimplemented!()`, `unreachable!()`, `todo!()`, `panic!()` or assertion in a function that returns `Result`",
|
|
move |diag| {
|
|
diag.help(
|
|
"`unimplemented!()`, `unreachable!()`, `todo!()`, `panic!()` or assertions should not be used in a function that returns `Result` as `Result` is expected to return an error instead of crashing",
|
|
);
|
|
diag.span_note(panics, "return Err() instead of panicking");
|
|
},
|
|
);
|
|
}
|
|
}
|