diff --git a/clippy_lints/src/undocumented_unsafe_blocks.rs b/clippy_lints/src/undocumented_unsafe_blocks.rs
index f8be71704c09..ee8d7a24e358 100644
--- a/clippy_lints/src/undocumented_unsafe_blocks.rs
+++ b/clippy_lints/src/undocumented_unsafe_blocks.rs
@@ -1,15 +1,17 @@
 use clippy_utils::diagnostics::span_lint_and_sugg;
 use clippy_utils::source::{snippet, indent_of, reindent_multiline};
 use rustc_errors::Applicability;
-use rustc_hir::{Block, BlockCheckMode, Expr, ExprKind, HirId, Local, MatchSource, UnsafeSource, YieldSource};
+use rustc_hir::{Block, BlockCheckMode, Expr, ExprKind, HirId, Local, UnsafeSource};
 use rustc_lexer::TokenKind;
+use rustc_middle::hir::map::Map;
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_middle::lint::in_external_macro;
 use rustc_middle::ty::TyCtxt;
 use rustc_session::{impl_lint_pass, declare_tool_lint};
 use rustc_span::{BytePos, Span};
 use std::borrow::Cow;
-use clippy_utils::is_lint_allowed;
+use clippy_utils::{is_lint_allowed, in_macro};
+use rustc_hir::intravisit::{NestedVisitorMap, Visitor, walk_expr};
 
 declare_clippy_lint! {
     /// ### What it does
@@ -70,13 +72,13 @@ impl LateLintPass<'_> for UndocumentedUnsafeBlocks {
 
                     let result = block_has_safety_comment(cx.tcx, enclosing_scope_hir_id, span);
 
-                    if result == Some(true) || result.is_none() {
+                    if result.unwrap_or(true) {
                         self.local_checked = true;
                         return;
                     }
                 }
 
-                err(cx, span);
+                lint(cx, span);
             }
         }
     }
@@ -86,12 +88,12 @@ impl LateLintPass<'_> for UndocumentedUnsafeBlocks {
             if !is_lint_allowed(cx, UNDOCUMENTED_UNSAFE_BLOCKS, local.hir_id);
             if !in_external_macro(cx.tcx.sess, local.span);
             if let Some(init) = local.init;
-            if let Some((block, element_count)) = find_block_in_expr(&init.kind);
-            if let BlockCheckMode::UnsafeBlock(UnsafeSource::UserProvided) = block.rules;
-            if cx.tcx.hir().get_enclosing_scope(block.hir_id).is_some();
             then {
-                self.local_level = self.local_level.saturating_add(element_count);
-                self.local_span = Some(local.span);
+                self.visit_expr(init);
+
+                if self.local_level > 0 {
+                    self.local_span = Some(local.span);
+                }
             }
         }
     }
@@ -106,94 +108,22 @@ impl LateLintPass<'_> for UndocumentedUnsafeBlocks {
     }
 }
 
-fn find_block_in_expr(expr_kind: &ExprKind<'hir>) -> Option<(&'tcx Block<'hir>, u32)> {
-    match expr_kind {
-        ExprKind::Array(elements) | ExprKind::Tup(elements) => {
-            let unsafe_blocks = elements
-                .iter()
-                .filter_map(|e| match e {
-                    Expr {
-                        kind:
-                        ExprKind::Block(
-                            block
-                            @
-                            Block {
-                                rules: BlockCheckMode::UnsafeBlock(UnsafeSource::UserProvided),
-                                ..
-                            },
-                            _,
-                        ),
-                        ..
-                    } => Some(block),
-                    _ => None,
-                })
-                .collect::<Vec<_>>();
+impl<'hir> Visitor<'hir> for UndocumentedUnsafeBlocks {
+    type Map = Map<'hir>;
 
-            if let Some(block) = unsafe_blocks.get(0) {
-                return Some((block, unsafe_blocks.len().try_into().unwrap()));
-            }
+    fn nested_visit_map(&mut self) -> NestedVisitorMap<Self::Map> {
+        NestedVisitorMap::None
+    }
 
-            None
+    fn visit_expr(&mut self, ex: &'v Expr<'v>) {
+        match ex.kind {
+            ExprKind::Block(_, _) => self.local_level = self.local_level.saturating_add(1),
+            _ => walk_expr(self, ex)
         }
-        ExprKind::Box(Expr {
-                          kind: ExprKind::Block(block, _),
-                          ..
-                      })
-        | ExprKind::Unary(
-            _,
-            Expr {
-                kind: ExprKind::Block(block, _),
-                ..
-            },
-        )
-        | ExprKind::Match(
-            Expr {
-                kind: ExprKind::Block(block, _),
-                ..
-            },
-            _,
-            MatchSource::Normal,
-        )
-        | ExprKind::Loop(block, _, _, _)
-        | ExprKind::Block(block, _)
-        | ExprKind::AddrOf(
-            _,
-            _,
-            Expr {
-                kind: ExprKind::Block(block, _),
-                ..
-            },
-        )
-        | ExprKind::Break(
-            _,
-            Some(Expr {
-                     kind: ExprKind::Block(block, _),
-                     ..
-                 }),
-        )
-        | ExprKind::Ret(Some(Expr {
-                                 kind: ExprKind::Block(block, _),
-                                 ..
-                             }))
-        | ExprKind::Repeat(
-            Expr {
-                kind: ExprKind::Block(block, _),
-                ..
-            },
-            _,
-        )
-        | ExprKind::Yield(
-            Expr {
-                kind: ExprKind::Block(block, _),
-                ..
-            },
-            YieldSource::Yield,
-        ) => Some((block, 1)),
-        _ => None,
     }
 }
 
-fn err(cx: &LateContext<'_>, span: Span) {
+fn lint(cx: &LateContext<'_>, span: Span) {
     let block_indent = indent_of(cx, span);
     let suggestion = format!("// Safety: ...\n{}", snippet(cx, span, ".."));
 
@@ -217,7 +147,12 @@ fn block_has_safety_comment(
     let source_map = tcx.sess.source_map();
 
     let enclosing_scope_span = map.opt_span(enclosing_hir_id)?;
-    let between_span = enclosing_scope_span.to(block_span);
+
+    let between_span = if in_macro(block_span) {
+        enclosing_scope_span.with_hi(block_span.hi())
+    } else {
+        enclosing_scope_span.to(block_span)
+    };
 
     let file_name = source_map.span_to_filename(between_span);
     let source_file = source_map.get_source_file(&file_name)?;
diff --git a/tests/ui/undocumented_unsafe_blocks.rs b/tests/ui/undocumented_unsafe_blocks.rs
index f887843aba81..52577323a583 100644
--- a/tests/ui/undocumented_unsafe_blocks.rs
+++ b/tests/ui/undocumented_unsafe_blocks.rs
@@ -169,6 +169,30 @@ fn comment_repeat() {
     let _ = [unsafe {}; 5];
 }
 
+fn comment_macro_call() {
+    macro_rules! t {
+        ($b:expr) => {
+            $b
+        };
+    }
+
+    t!(
+        // Safety:
+        unsafe {}
+    );
+}
+
+fn comment_macro_def() {
+    macro_rules! t {
+        () => {
+            // Safety:
+            unsafe {}
+        };
+    }
+
+    t!();
+}
+
 fn non_ascii_comment() {
     // ॐ᧻໒ Safety: ௵∰
     unsafe {};
@@ -180,6 +204,11 @@ fn local_commented_block() {
         unsafe {};
 }
 
+fn local_nest() {
+    // Safety:
+    let _ = [(42, unsafe {}, unsafe {}), (52, unsafe {}, unsafe {})];
+}
+
 // Invalid comments
 
 fn no_comment() {
@@ -217,6 +246,26 @@ fn local_no_comment() {
     let _ = unsafe {};
 }
 
+fn no_comment_macro_call() {
+    macro_rules! t {
+        ($b:expr) => {
+            $b
+        };
+    }
+
+    t!(unsafe {});
+}
+
+fn no_comment_macro_def() {
+    macro_rules! t {
+        () => {
+            unsafe {}
+        };
+    }
+
+    t!();
+}
+
 fn trailing_comment() {
     unsafe {} // Safety:
 }
diff --git a/tests/ui/undocumented_unsafe_blocks.stderr b/tests/ui/undocumented_unsafe_blocks.stderr
index 7baab11034a8..3f88ae4cec4d 100644
--- a/tests/ui/undocumented_unsafe_blocks.stderr
+++ b/tests/ui/undocumented_unsafe_blocks.stderr
@@ -1,5 +1,5 @@
 error: unsafe block missing a safety comment
-  --> $DIR/undocumented_unsafe_blocks.rs:186:5
+  --> $DIR/undocumented_unsafe_blocks.rs:215:5
    |
 LL |     unsafe {}
    |     ^^^^^^^^^
@@ -12,7 +12,7 @@ LL +     unsafe {}
    |
 
 error: unsafe block missing a safety comment
-  --> $DIR/undocumented_unsafe_blocks.rs:190:5
+  --> $DIR/undocumented_unsafe_blocks.rs:219:5
    |
 LL |     let _ = [unsafe { 14 }, unsafe { 15 }, 42, unsafe { 16 }];
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -24,7 +24,7 @@ LL +     let _ = [unsafe { 14 }, unsafe { 15 }, 42, unsafe { 16 }];
    |
 
 error: unsafe block missing a safety comment
-  --> $DIR/undocumented_unsafe_blocks.rs:194:5
+  --> $DIR/undocumented_unsafe_blocks.rs:223:5
    |
 LL |     let _ = (42, unsafe {}, "test", unsafe {});
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -36,7 +36,7 @@ LL +     let _ = (42, unsafe {}, "test", unsafe {});
    |
 
 error: unsafe block missing a safety comment
-  --> $DIR/undocumented_unsafe_blocks.rs:198:5
+  --> $DIR/undocumented_unsafe_blocks.rs:227:5
    |
 LL |     let _ = *unsafe { &42 };
    |     ^^^^^^^^^^^^^^^^^^^^^^^^
@@ -48,7 +48,7 @@ LL +     let _ = *unsafe { &42 };
    |
 
 error: unsafe block missing a safety comment
-  --> $DIR/undocumented_unsafe_blocks.rs:203:5
+  --> $DIR/undocumented_unsafe_blocks.rs:232:5
    |
 LL | /     let _ = match unsafe {} {
 LL | |         _ => {},
@@ -64,7 +64,7 @@ LL +         };
    |
 
 error: unsafe block missing a safety comment
-  --> $DIR/undocumented_unsafe_blocks.rs:209:5
+  --> $DIR/undocumented_unsafe_blocks.rs:238:5
    |
 LL |     let _ = &unsafe {};
    |     ^^^^^^^^^^^^^^^^^^^
@@ -76,7 +76,7 @@ LL +     let _ = &unsafe {};
    |
 
 error: unsafe block missing a safety comment
-  --> $DIR/undocumented_unsafe_blocks.rs:213:5
+  --> $DIR/undocumented_unsafe_blocks.rs:242:5
    |
 LL |     let _ = [unsafe {}; 5];
    |     ^^^^^^^^^^^^^^^^^^^^^^^
@@ -88,7 +88,7 @@ LL +     let _ = [unsafe {}; 5];
    |
 
 error: unsafe block missing a safety comment
-  --> $DIR/undocumented_unsafe_blocks.rs:217:5
+  --> $DIR/undocumented_unsafe_blocks.rs:246:5
    |
 LL |     let _ = unsafe {};
    |     ^^^^^^^^^^^^^^^^^^
@@ -100,7 +100,35 @@ LL +     let _ = unsafe {};
    |
 
 error: unsafe block missing a safety comment
-  --> $DIR/undocumented_unsafe_blocks.rs:221:5
+  --> $DIR/undocumented_unsafe_blocks.rs:256:8
+   |
+LL |     t!(unsafe {});
+   |        ^^^^^^^^^
+   |
+help: consider adding a safety comment
+   |
+LL ~     t!(// Safety: ...
+LL ~     unsafe {});
+   |
+
+error: unsafe block missing a safety comment
+  --> $DIR/undocumented_unsafe_blocks.rs:262:13
+   |
+LL |             unsafe {}
+   |             ^^^^^^^^^
+...
+LL |     t!();
+   |     ----- in this macro invocation
+   |
+   = note: this error originates in the macro `t` (in Nightly builds, run with -Z macro-backtrace for more info)
+help: consider adding a safety comment
+   |
+LL ~             // Safety: ...
+LL +     unsafe {}
+   |
+
+error: unsafe block missing a safety comment
+  --> $DIR/undocumented_unsafe_blocks.rs:270:5
    |
 LL |     unsafe {} // Safety:
    |     ^^^^^^^^^
@@ -112,7 +140,7 @@ LL ~     unsafe {} // Safety:
    |
 
 error: unsafe block missing a safety comment
-  --> $DIR/undocumented_unsafe_blocks.rs:225:5
+  --> $DIR/undocumented_unsafe_blocks.rs:274:5
    |
 LL | /     unsafe {
 LL | |         // Safety:
@@ -128,7 +156,7 @@ LL +         }
    |
 
 error: unsafe block missing a safety comment
-  --> $DIR/undocumented_unsafe_blocks.rs:235:5
+  --> $DIR/undocumented_unsafe_blocks.rs:284:5
    |
 LL |     unsafe {};
    |     ^^^^^^^^^
@@ -139,5 +167,5 @@ LL ~     // Safety: ...
 LL ~     unsafe {};
    |
 
-error: aborting due to 11 previous errors
+error: aborting due to 13 previous errors