-use crate::utils::{is_type_diagnostic_item, method_chain_args, return_ty, span_lint_and_then};
+use clippy_utils::diagnostics::span_lint_and_then;
+use clippy_utils::ty::is_type_diagnostic_item;
+use clippy_utils::{method_chain_args, return_ty};
use if_chain::if_chain;
use rustc_hir as hir;
+use rustc_hir::intravisit::{self, Visitor};
+use rustc_hir::{Expr, ImplItemKind};
use rustc_lint::{LateContext, LateLintPass};
-use rustc_middle::hir::map::Map;
use rustc_middle::ty;
use rustc_session::{declare_lint_pass, declare_tool_lint};
use rustc_span::{sym, Span};
declare_clippy_lint! {
- /// **What it does:** Checks for functions of type Result that contain `expect()` or `unwrap()`
+ /// ### What it does
+ /// Checks for functions of type `Result` that contain `expect()` or `unwrap()`
///
- /// **Why is this bad?** These functions promote recoverable errors to non-recoverable errors which may be undesirable in code bases which wish to avoid panics.
+ /// ### Why is this bad?
+ /// These functions promote recoverable errors to non-recoverable errors which may be undesirable in code bases which wish to avoid panics.
///
- /// **Known problems:** This can cause false positives in functions that handle both recoverable and non recoverable errors.
+ /// ### Known problems
+ /// This can cause false positives in functions that handle both recoverable and non recoverable errors.
///
- /// **Example:**
+ /// ### Example
/// Before:
/// ```rust
/// fn divisible_by_3(i_str: String) -> Result<(), String> {
/// Ok(())
/// }
/// ```
+ #[clippy::version = "1.48.0"]
pub UNWRAP_IN_RESULT,
restriction,
"functions of type `Result<..>` or `Option`<...> that contain `expect()` or `unwrap()`"
// first check if it's a method or function
if let hir::ImplItemKind::Fn(ref _signature, _) = impl_item.kind;
// checking if its return type is `result` or `option`
- if is_type_diagnostic_item(cx, return_ty(cx, impl_item.hir_id()), sym::result_type)
- || is_type_diagnostic_item(cx, return_ty(cx, impl_item.hir_id()), sym::option_type);
+ if is_type_diagnostic_item(cx, return_ty(cx, impl_item.hir_id()), sym::Result)
+ || is_type_diagnostic_item(cx, return_ty(cx, impl_item.hir_id()), sym::Option);
then {
lint_impl_body(cx, impl_item.span, impl_item);
}
}
}
-use rustc_hir::intravisit::{self, NestedVisitorMap, Visitor};
-use rustc_hir::{Expr, ImplItemKind};
-
struct FindExpectUnwrap<'a, 'tcx> {
lcx: &'a LateContext<'tcx>,
typeck_results: &'tcx ty::TypeckResults<'tcx>,
}
impl<'a, 'tcx> Visitor<'tcx> for FindExpectUnwrap<'a, 'tcx> {
- type Map = Map<'tcx>;
-
fn visit_expr(&mut self, expr: &'tcx Expr<'_>) {
// check for `expect`
if let Some(arglists) = method_chain_args(expr, &["expect"]) {
let reciever_ty = self.typeck_results.expr_ty(&arglists[0][0]).peel_refs();
- if is_type_diagnostic_item(self.lcx, reciever_ty, sym::option_type)
- || is_type_diagnostic_item(self.lcx, reciever_ty, sym::result_type)
+ if is_type_diagnostic_item(self.lcx, reciever_ty, sym::Option)
+ || is_type_diagnostic_item(self.lcx, reciever_ty, sym::Result)
{
self.result.push(expr.span);
}
// check for `unwrap`
if let Some(arglists) = method_chain_args(expr, &["unwrap"]) {
let reciever_ty = self.typeck_results.expr_ty(&arglists[0][0]).peel_refs();
- if is_type_diagnostic_item(self.lcx, reciever_ty, sym::option_type)
- || is_type_diagnostic_item(self.lcx, reciever_ty, sym::result_type)
+ if is_type_diagnostic_item(self.lcx, reciever_ty, sym::Option)
+ || is_type_diagnostic_item(self.lcx, reciever_ty, sym::Result)
{
self.result.push(expr.span);
}
// and check sub-expressions
intravisit::walk_expr(self, expr);
}
-
- fn nested_visit_map(&mut self) -> NestedVisitorMap<Self::Map> {
- NestedVisitorMap::None
- }
}
fn lint_impl_body<'tcx>(cx: &LateContext<'tcx>, impl_span: Span, impl_item: &'tcx hir::ImplItem<'_>) {
- if_chain! {
+ if let ImplItemKind::Fn(_, body_id) = impl_item.kind {
+ let body = cx.tcx.hir().body(body_id);
+ let mut fpu = FindExpectUnwrap {
+ lcx: cx,
+ typeck_results: cx.tcx.typeck(impl_item.def_id),
+ result: Vec::new(),
+ };
+ fpu.visit_expr(&body.value);
- if let ImplItemKind::Fn(_, body_id) = impl_item.kind;
- then {
- let body = cx.tcx.hir().body(body_id);
- let mut fpu = FindExpectUnwrap {
- lcx: cx,
- typeck_results: cx.tcx.typeck(impl_item.def_id),
- result: Vec::new(),
- };
- fpu.visit_expr(&body.value);
-
- // if we've found one, lint
- if !fpu.result.is_empty() {
- span_lint_and_then(
- cx,
- UNWRAP_IN_RESULT,
- impl_span,
- "used unwrap or expect in a function that returns result or option",
- move |diag| {
- diag.help(
- "unwrap and expect should not be used in a function that returns result or option" );
- diag.span_note(fpu.result, "potential non-recoverable error(s)");
- });
- }
+ // if we've found one, lint
+ if !fpu.result.is_empty() {
+ span_lint_and_then(
+ cx,
+ UNWRAP_IN_RESULT,
+ impl_span,
+ "used unwrap or expect in a function that returns result or option",
+ move |diag| {
+ diag.help("unwrap and expect should not be used in a function that returns result or option");
+ diag.span_note(fpu.result, "potential non-recoverable error(s)");
+ },
+ );
}
}
}
projects / rust.git / blobdiff