-use crate::utils::paths::{BEGIN_PANIC, BEGIN_PANIC_FMT, FROM_TRAIT};
-use crate::utils::{
- is_expn_of, is_type_diagnostic_item, match_def_path, method_chain_args, span_lint_and_then, walk_ptrs_ty,
-};
+use clippy_utils::diagnostics::span_lint_and_then;
+use clippy_utils::ty::is_type_diagnostic_item;
+use clippy_utils::{is_expn_of, match_panic_def_id, method_chain_args};
use if_chain::if_chain;
use rustc_hir as hir;
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::Span;
+use rustc_span::{sym, Span};
declare_clippy_lint! {
- /// **What it does:** Checks for impls of `From<..>` that contain `panic!()` or `unwrap()`
+ /// ### What it does
+ /// Checks for impls of `From<..>` that contain `panic!()` or `unwrap()`
///
- /// **Why is this bad?** `TryFrom` should be used if there's a possibility of failure.
+ /// ### Why is this bad?
+ /// `TryFrom` should be used if there's a possibility of failure.
///
- /// **Known problems:** None.
- ///
- /// **Example:**
+ /// ### Example
/// ```rust
/// struct Foo(i32);
+ ///
+ /// // Bad
/// impl From<String> for Foo {
/// fn from(s: String) -> Self {
/// Foo(s.parse().unwrap())
/// }
/// }
/// ```
+ ///
+ /// ```rust
+ /// // Good
+ /// struct Foo(i32);
+ ///
+ /// use std::convert::TryFrom;
+ /// impl TryFrom<String> for Foo {
+ /// type Error = ();
+ /// fn try_from(s: String) -> Result<Self, Self::Error> {
+ /// if let Ok(parsed) = s.parse() {
+ /// Ok(Foo(parsed))
+ /// } else {
+ /// Err(())
+ /// }
+ /// }
+ /// }
+ /// ```
pub FALLIBLE_IMPL_FROM,
nursery,
"Warn on impls of `From<..>` that contain `panic!()` or `unwrap()`"
declare_lint_pass!(FallibleImplFrom => [FALLIBLE_IMPL_FROM]);
-impl<'a, 'tcx> LateLintPass<'a, 'tcx> for FallibleImplFrom {
- fn check_item(&mut self, cx: &LateContext<'a, 'tcx>, item: &'tcx hir::Item<'_>) {
+impl<'tcx> LateLintPass<'tcx> for FallibleImplFrom {
+ fn check_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx hir::Item<'_>) {
// check for `impl From<???> for ..`
- let impl_def_id = cx.tcx.hir().local_def_id(item.hir_id);
if_chain! {
- if let hir::ItemKind::Impl{ items: impl_items, .. } = item.kind;
- if let Some(impl_trait_ref) = cx.tcx.impl_trait_ref(impl_def_id);
- if match_def_path(cx, impl_trait_ref.def_id, &FROM_TRAIT);
+ if let hir::ItemKind::Impl(impl_) = &item.kind;
+ if let Some(impl_trait_ref) = cx.tcx.impl_trait_ref(item.def_id);
+ if cx.tcx.is_diagnostic_item(sym::from_trait, impl_trait_ref.def_id);
then {
- lint_impl_body(cx, item.span, impl_items);
+ lint_impl_body(cx, item.span, impl_.items);
}
}
}
}
-fn lint_impl_body<'a, 'tcx>(cx: &LateContext<'a, 'tcx>, impl_span: Span, impl_items: &[hir::ImplItemRef<'_>]) {
+fn lint_impl_body<'tcx>(cx: &LateContext<'tcx>, impl_span: Span, impl_items: &[hir::ImplItemRef<'_>]) {
use rustc_hir::intravisit::{self, NestedVisitorMap, Visitor};
use rustc_hir::{Expr, ExprKind, ImplItemKind, QPath};
struct FindPanicUnwrap<'a, 'tcx> {
- lcx: &'a LateContext<'a, 'tcx>,
- tables: &'tcx ty::TypeckTables<'tcx>,
+ lcx: &'a LateContext<'tcx>,
+ typeck_results: &'tcx ty::TypeckResults<'tcx>,
result: Vec<Span>,
}
fn visit_expr(&mut self, expr: &'tcx Expr<'_>) {
// check for `begin_panic`
if_chain! {
- if let ExprKind::Call(ref func_expr, _) = expr.kind;
- if let ExprKind::Path(QPath::Resolved(_, ref path)) = func_expr.kind;
+ if let ExprKind::Call(func_expr, _) = expr.kind;
+ if let ExprKind::Path(QPath::Resolved(_, path)) = func_expr.kind;
if let Some(path_def_id) = path.res.opt_def_id();
- if match_def_path(self.lcx, path_def_id, &BEGIN_PANIC) ||
- match_def_path(self.lcx, path_def_id, &BEGIN_PANIC_FMT);
+ if match_panic_def_id(self.lcx, path_def_id);
if is_expn_of(expr.span, "unreachable").is_none();
then {
self.result.push(expr.span);
// check for `unwrap`
if let Some(arglists) = method_chain_args(expr, &["unwrap"]) {
- let reciever_ty = walk_ptrs_ty(self.tables.expr_ty(&arglists[0][0]));
- if is_type_diagnostic_item(self.lcx, reciever_ty, sym!(option_type))
- || is_type_diagnostic_item(self.lcx, reciever_ty, sym!(result_type))
+ 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)
{
self.result.push(expr.span);
}
for impl_item in impl_items {
if_chain! {
- if impl_item.ident.name == sym!(from);
+ if impl_item.ident.name == sym::from;
if let ImplItemKind::Fn(_, body_id) =
cx.tcx.hir().impl_item(impl_item.id).kind;
then {
// check the body for `begin_panic` or `unwrap`
let body = cx.tcx.hir().body(body_id);
- let impl_item_def_id = cx.tcx.hir().local_def_id(impl_item.id.hir_id);
let mut fpu = FindPanicUnwrap {
lcx: cx,
- tables: cx.tcx.typeck_tables_of(impl_item_def_id),
+ typeck_results: cx.tcx.typeck(impl_item.id.def_id),
result: Vec::new(),
};
fpu.visit_expr(&body.value);
move |diag| {
diag.help(
"`From` is intended for infallible conversions only. \
- Use `TryFrom` if there's a possibility for the conversion to fail.");
+ Use `TryFrom` if there's a possibility for the conversion to fail");
diag.span_note(fpu.result, "potential failure(s)");
});
}
projects / rust.git / blobdiff