Add undocumented_unsafe_blocks lint

2 files changed, 446 insertions, 0 deletions

diff --git a/tests/ui/undocumented_unsafe_blocks.rs b/tests/ui/undocumented_unsafe_blocks.rs
new file mode 100644
index 00000000000..52577323a58
--- /dev/null
+++ b/tests/ui/undocumented_unsafe_blocks.rs
@@ -0,0 +1,287 @@
+#![warn(clippy::undocumented_unsafe_blocks)]
+
+// Valid comments
+
+fn nested_local() {
+    let _ = {
+        let _ = {
+            // Safety:
+            let _ = unsafe {};
+        };
+    };
+}
+
+fn deep_nest() {
+    let _ = {
+        let _ = {
+            // Safety:
+            let _ = unsafe {};
+
+            // Safety:
+            unsafe {};
+
+            let _ = {
+                let _ = {
+                    let _ = {
+                        let _ = {
+                            let _ = {
+                                // Safety:
+                                let _ = unsafe {};
+
+                                // Safety:
+                                unsafe {};
+                            };
+                        };
+                    };
+
+                    // Safety:
+                    unsafe {};
+                };
+            };
+        };
+
+        // Safety:
+        unsafe {};
+    };
+
+    // Safety:
+    unsafe {};
+}
+
+fn local_tuple_expression() {
+    // Safety:
+    let _ = (42, unsafe {});
+}
+
+fn line_comment() {
+    // Safety:
+    unsafe {}
+}
+
+fn line_comment_newlines() {
+    // Safety:
+
+    unsafe {}
+}
+
+fn line_comment_empty() {
+    // Safety:
+    //
+    //
+    //
+    unsafe {}
+}
+
+fn line_comment_with_extras() {
+    // This is a description
+    // Safety:
+    unsafe {}
+}
+
+fn block_comment() {
+    /* Safety: */
+    unsafe {}
+}
+
+fn block_comment_newlines() {
+    /* Safety: */
+
+    unsafe {}
+}
+
+#[rustfmt::skip]
+fn inline_block_comment() {
+    /* Safety: */unsafe {}
+}
+
+fn block_comment_with_extras() {
+    /* This is a description
+     * Safety:
+     */
+    unsafe {}
+}
+
+fn block_comment_terminator_same_line() {
+    /* This is a description
+     * Safety: */
+    unsafe {}
+}
+
+fn buried_safety() {
+    // Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor
+    // incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation
+    // ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in
+    // reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint
+    // occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est
+    // laborum. Safety:
+    // Tellus elementum sagittis vitae et leo duis ut diam quam. Sit amet nulla facilisi
+    // morbi tempus iaculis urna. Amet luctus venenatis lectus magna. At quis risus sed vulputate odio
+    // ut. Luctus venenatis lectus magna fringilla urna. Tortor id aliquet lectus proin nibh nisl
+    // condimentum id venenatis. Vulputate dignissim suspendisse in est ante in nibh mauris cursus.
+    unsafe {}
+}
+
+fn safety_with_prepended_text() {
+    // This is a test. Safety:
+    unsafe {}
+}
+
+fn local_line_comment() {
+    // Safety:
+    let _ = unsafe {};
+}
+
+fn local_block_comment() {
+    /* Safety: */
+    let _ = unsafe {};
+}
+
+fn comment_array() {
+    // Safety:
+    let _ = [unsafe { 14 }, unsafe { 15 }, 42, unsafe { 16 }];
+}
+
+fn comment_tuple() {
+    // Safety:
+    let _ = (42, unsafe {}, "test", unsafe {});
+}
+
+fn comment_unary() {
+    // Safety:
+    let _ = *unsafe { &42 };
+}
+
+#[allow(clippy::match_single_binding)]
+fn comment_match() {
+    // Safety:
+    let _ = match unsafe {} {
+        _ => {},
+    };
+}
+
+fn comment_addr_of() {
+    // Safety:
+    let _ = &unsafe {};
+}
+
+fn comment_repeat() {
+    // Safety:
+    let _ = [unsafe {}; 5];
+}
+
+fn comment_macro_call() {
+    macro_rules! t {
+        ($b:expr) => {
+            $b
+        };
+    }
+
+    t!(
+        // Safety:
+        unsafe {}
+    );
+}
+
+fn comment_macro_def() {
+    macro_rules! t {
+        () => {
+            // Safety:
+            unsafe {}
+        };
+    }
+
+    t!();
+}
+
+fn non_ascii_comment() {
+    // ॐ᧻໒ Safety: ௵∰
+    unsafe {};
+}
+
+fn local_commented_block() {
+    let _ =
+        // Safety:
+        unsafe {};
+}
+
+fn local_nest() {
+    // Safety:
+    let _ = [(42, unsafe {}, unsafe {}), (52, unsafe {}, unsafe {})];
+}
+
+// Invalid comments
+
+fn no_comment() {
+    unsafe {}
+}
+
+fn no_comment_array() {
+    let _ = [unsafe { 14 }, unsafe { 15 }, 42, unsafe { 16 }];
+}
+
+fn no_comment_tuple() {
+    let _ = (42, unsafe {}, "test", unsafe {});
+}
+
+fn no_comment_unary() {
+    let _ = *unsafe { &42 };
+}
+
+#[allow(clippy::match_single_binding)]
+fn no_comment_match() {
+    let _ = match unsafe {} {
+        _ => {},
+    };
+}
+
+fn no_comment_addr_of() {
+    let _ = &unsafe {};
+}
+
+fn no_comment_repeat() {
+    let _ = [unsafe {}; 5];
+}
+
+fn local_no_comment() {
+    let _ = unsafe {};
+}
+
+fn no_comment_macro_call() {
+    macro_rules! t {
+        ($b:expr) => {
+            $b
+        };
+    }
+
+    t!(unsafe {});
+}
+
+fn no_comment_macro_def() {
+    macro_rules! t {
+        () => {
+            unsafe {}
+        };
+    }
+
+    t!();
+}
+
+fn trailing_comment() {
+    unsafe {} // Safety:
+}
+
+fn internal_comment() {
+    unsafe {
+        // Safety:
+    }
+}
+
+fn interference() {
+    // Safety
+
+    let _ = 42;
+
+    unsafe {};
+}
+
+fn main() {}
diff --git a/tests/ui/undocumented_unsafe_blocks.stderr b/tests/ui/undocumented_unsafe_blocks.stderr
new file mode 100644
index 00000000000..b32069a334c
--- /dev/null
+++ b/tests/ui/undocumented_unsafe_blocks.stderr
@@ -0,0 +1,159 @@
+error: unsafe block missing a safety comment
+  --> $DIR/undocumented_unsafe_blocks.rs:215:5
+   |
+LL |     unsafe {}
+   |     ^^^^^^^^^
+   |
+   = note: `-D clippy::undocumented-unsafe-blocks` implied by `-D warnings`
+help: consider adding a safety comment
+   |
+LL ~     // Safety: ...
+LL +     unsafe {}
+   |
+
+error: unsafe block missing a safety comment
+  --> $DIR/undocumented_unsafe_blocks.rs:219:5
+   |
+LL |     let _ = [unsafe { 14 }, unsafe { 15 }, 42, unsafe { 16 }];
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+help: consider adding a safety comment
+   |
+LL ~     // Safety: ...
+LL +     let _ = [unsafe { 14 }, unsafe { 15 }, 42, unsafe { 16 }];
+   |
+
+error: unsafe block missing a safety comment
+  --> $DIR/undocumented_unsafe_blocks.rs:223:5
+   |
+LL |     let _ = (42, unsafe {}, "test", unsafe {});
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+help: consider adding a safety comment
+   |
+LL ~     // Safety: ...
+LL +     let _ = (42, unsafe {}, "test", unsafe {});
+   |
+
+error: unsafe block missing a safety comment
+  --> $DIR/undocumented_unsafe_blocks.rs:227:5
+   |
+LL |     let _ = *unsafe { &42 };
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+help: consider adding a safety comment
+   |
+LL ~     // Safety: ...
+LL +     let _ = *unsafe { &42 };
+   |
+
+error: unsafe block missing a safety comment
+  --> $DIR/undocumented_unsafe_blocks.rs:232:5
+   |
+LL |     let _ = match unsafe {} {
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+help: consider adding a safety comment
+   |
+LL ~     // Safety: ...
+LL +     let _ = match unsafe {} {
+   |
+
+error: unsafe block missing a safety comment
+  --> $DIR/undocumented_unsafe_blocks.rs:238:5
+   |
+LL |     let _ = &unsafe {};
+   |     ^^^^^^^^^^^^^^^^^^^
+   |
+help: consider adding a safety comment
+   |
+LL ~     // Safety: ...
+LL +     let _ = &unsafe {};
+   |
+
+error: unsafe block missing a safety comment
+  --> $DIR/undocumented_unsafe_blocks.rs:242:5
+   |
+LL |     let _ = [unsafe {}; 5];
+   |     ^^^^^^^^^^^^^^^^^^^^^^^
+   |
+help: consider adding a safety comment
+   |
+LL ~     // Safety: ...
+LL +     let _ = [unsafe {}; 5];
+   |
+
+error: unsafe block missing a safety comment
+  --> $DIR/undocumented_unsafe_blocks.rs:246:5
+   |
+LL |     let _ = unsafe {};
+   |     ^^^^^^^^^^^^^^^^^^
+   |
+help: consider adding a safety comment
+   |
+LL ~     // Safety: ...
+LL +     let _ = unsafe {};
+   |
+
+error: unsafe block missing a safety comment
+  --> $DIR/undocumented_unsafe_blocks.rs:256:8
+   |
+LL |     t!(unsafe {});
+   |        ^^^^^^^^^
+   |
+help: consider adding a safety comment
+   |
+LL ~     t!(// Safety: ...
+LL ~     unsafe {});
+   |
+
+error: unsafe block in macro expansion missing a safety comment
+  --> $DIR/undocumented_unsafe_blocks.rs:262:13
+   |
+LL |             unsafe {}
+   |             ^^^^^^^^^
+...
+LL |     t!();
+   |     ----- in this macro invocation
+   |
+   = help: consider adding a safety comment in the macro definition
+   = note: this error originates in the macro `t` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: unsafe block missing a safety comment
+  --> $DIR/undocumented_unsafe_blocks.rs:270:5
+   |
+LL |     unsafe {} // Safety:
+   |     ^^^^^^^^^
+   |
+help: consider adding a safety comment
+   |
+LL ~     // Safety: ...
+LL ~     unsafe {} // Safety:
+   |
+
+error: unsafe block missing a safety comment
+  --> $DIR/undocumented_unsafe_blocks.rs:274:5
+   |
+LL |     unsafe {
+   |     ^^^^^^^^
+   |
+help: consider adding a safety comment
+   |
+LL ~     // Safety: ...
+LL +     unsafe {
+   |
+
+error: unsafe block missing a safety comment
+  --> $DIR/undocumented_unsafe_blocks.rs:284:5
+   |
+LL |     unsafe {};
+   |     ^^^^^^^^^
+   |
+help: consider adding a safety comment
+   |
+LL ~     // Safety: ...
+LL ~     unsafe {};
+   |
+
+error: aborting due to 13 previous errors
+