From d8716f5a3fb32dfaa77e298129dae193b0b8c650 Mon Sep 17 00:00:00 2001
From: daxpedda <daxpedda@gmail.com>
Date: Mon, 17 Feb 2020 02:38:48 +0100
Subject: [PATCH] Fix ICE.

---
 clippy_lints/src/doc.rs | 43 +++++++++++++++++++++--------------------
 1 file changed, 22 insertions(+), 21 deletions(-)

diff --git a/clippy_lints/src/doc.rs b/clippy_lints/src/doc.rs
index 133a20b669a..c1285ad3646 100644
--- a/clippy_lints/src/doc.rs
+++ b/clippy_lints/src/doc.rs
@@ -153,11 +153,11 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for DocMarkdown {
     fn check_item(&mut self, cx: &LateContext<'a, 'tcx>, item: &'tcx hir::Item<'_>) {
         let headers = check_attrs(cx, &self.valid_idents, &item.attrs);
         match item.kind {
-            hir::ItemKind::Fn(ref sig, ..) => {
+            hir::ItemKind::Fn(ref sig, _, body_id) => {
                 if !(is_entrypoint_fn(cx, cx.tcx.hir().local_def_id(item.hir_id))
                     || in_external_macro(cx.tcx.sess, item.span))
                 {
-                    lint_for_missing_headers(cx, item.hir_id, item.span, sig, headers);
+                    lint_for_missing_headers(cx, item.hir_id, item.span, sig, headers, Some(body_id));
                 }
             },
             hir::ItemKind::Impl {
@@ -180,7 +180,7 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for DocMarkdown {
         let headers = check_attrs(cx, &self.valid_idents, &item.attrs);
         if let hir::TraitItemKind::Method(ref sig, ..) = item.kind {
             if !in_external_macro(cx.tcx.sess, item.span) {
-                lint_for_missing_headers(cx, item.hir_id, item.span, sig, headers);
+                lint_for_missing_headers(cx, item.hir_id, item.span, sig, headers, None);
             }
         }
     }
@@ -190,8 +190,8 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for DocMarkdown {
         if self.in_trait_impl || in_external_macro(cx.tcx.sess, item.span) {
             return;
         }
-        if let hir::ImplItemKind::Method(ref sig, ..) = item.kind {
-            lint_for_missing_headers(cx, item.hir_id, item.span, sig, headers);
+        if let hir::ImplItemKind::Method(ref sig, body_id) = item.kind {
+            lint_for_missing_headers(cx, item.hir_id, item.span, sig, headers, Some(body_id));
         }
     }
 }
@@ -202,6 +202,7 @@ fn lint_for_missing_headers<'a, 'tcx>(
     span: impl Into<MultiSpan> + Copy,
     sig: &hir::FnSig<'_>,
     headers: DocHeaders,
+    body_id: Option<hir::BodyId>,
 ) {
     if !cx.access_levels.is_exported(hir_id) {
         return; // Private functions do not require doc comments
@@ -222,24 +223,24 @@ fn lint_for_missing_headers<'a, 'tcx>(
                 span,
                 "docs for function returning `Result` missing `# Errors` section",
             );
-        } else {
-            let def_id = cx.tcx.hir().local_def_id(hir_id);
+        } else if let (Some(body_id), Some(future)) = (body_id, get_trait_def_id(cx, &paths::FUTURE)) {
+            let def_id = cx.tcx.hir().body_owner_def_id(body_id);
             let mir = cx.tcx.optimized_mir(def_id);
-            if let Some(future) = get_trait_def_id(cx, &paths::FUTURE) {
-                if implements_trait(cx, mir.return_ty(), future, &[]) {
-                    use TyKind::*;
+            let ret_ty = mir.return_ty();
 
-                    if let Opaque(_, subs) = mir.return_ty().kind {
-                        if let Some(ty) = subs.types().next() {
-                            if let Generator(_, subs, _) = ty.kind {
-                                if match_type(cx, subs.as_generator().return_ty(def_id, cx.tcx), &paths::RESULT) {
-                                    span_lint(
-                                        cx,
-                                        MISSING_ERRORS_DOC,
-                                        span,
-                                        "docs for function returning `Result` missing `# Errors` section",
-                                    );
-                                }
+            if implements_trait(cx, ret_ty, future, &[]) {
+                use TyKind::*;
+
+                if let Opaque(_, subs) = ret_ty.kind {
+                    if let Some(ty) = subs.types().next() {
+                        if let Generator(_, subs, _) = ty.kind {
+                            if match_type(cx, subs.as_generator().return_ty(def_id, cx.tcx), &paths::RESULT) {
+                                span_lint(
+                                    cx,
+                                    MISSING_ERRORS_DOC,
+                                    span,
+                                    "docs for function returning `Result` missing `# Errors` section",
+                                );
                             }
                         }
                     }