Resolved conflicts

clippy_lints/src/undocumented_unsafe_blocks.rs

@@ -2,12 +2,14 @@ use clippy_utils::diagnostics::span_lint_and_help;
 use clippy_utils::is_lint_allowed;
 use clippy_utils::source::walk_span_to_context;
 use rustc_data_structures::sync::Lrc;
+use rustc_hir as hir;
 use rustc_hir::{Block, BlockCheckMode, UnsafeSource};
 use rustc_lexer::{tokenize, TokenKind};
 use rustc_lint::{LateContext, LateLintPass, LintContext};
 use rustc_middle::lint::in_external_macro;
 use rustc_session::{declare_lint_pass, declare_tool_lint};
-use rustc_span::{BytePos, Pos, SyntaxContext};
+use rustc_span::{BytePos, Pos, Span, SyntaxContext};
+use std::rc::Rc;
 
 declare_clippy_lint! {
     /// ### What it does
@@ -86,6 +88,66 @@ impl LateLintPass<'_> for UndocumentedUnsafeBlocks {
             );
         }
     }
+
+    fn check_mod(&mut self, cx: &LateContext<'_>, module: &'_ hir::Mod<'_>, mod_span: Span, hir_id: hir::HirId) {
+        let source_map = cx.sess().source_map();
+        let mut item_and_spans: Vec<(&hir::Item<'_>, Span)> = Vec::new(); // (start, end, item)
+
+        // Collect all items and their spans
+        for item_id in module.item_ids {
+            let item = cx.tcx.hir().item(*item_id);
+            item_and_spans.push((item, item.span));
+        }
+        // Sort items by start position
+        item_and_spans.sort_by_key(|e| e.1.lo());
+
+        for (idx, (item, item_span)) in item_and_spans.iter().enumerate() {
+            if let hir::ItemKind::Impl(imple) = &item.kind
+                && imple.unsafety == hir::Unsafety::Unsafe
+                && !item_span.from_expansion()
+                && !is_lint_allowed(cx, UNDOCUMENTED_UNSAFE_BLOCKS, hir_id)
+            {
+                // Checks if the lines immediately preceding the impl contain a safety comment.
+                let impl_has_safety_comment = {
+                    let span_before_impl = if idx == 0 {
+                        // mod A { /* comment */ unsafe impl T {} }
+                        // ^--------------------^
+                        todo!();
+                        //mod_span.until(module.spans)
+                    } else {
+                        // unsafe impl S {} /* comment */ unsafe impl T {}
+                        //                 ^-------------^
+                        item_and_spans[idx - 1].1.between(*item_span)
+                    };
+
+                    if let Ok(start) = source_map.lookup_line(span_before_impl.lo())
+                        && let Ok(end) = source_map.lookup_line(span_before_impl.hi())
+                        && let Some(src) = start.sf.src.as_deref()
+                    {
+                        start.line < end.line && text_has_safety_comment(
+                            src,
+                            &start.sf.lines[start.line + 1 ..= end.line],
+                            start.sf.start_pos.to_usize()
+                        )
+                    } else {
+                        // Problem getting source text. Pretend a comment was found.
+                        true
+                    }
+                };
+
+                if !impl_has_safety_comment {
+                    span_lint_and_help(
+                        cx,
+                        UNDOCUMENTED_UNSAFE_BLOCKS,
+                        *item_span,
+                        "unsafe impl missing a safety comment",
+                        None,
+                        "consider adding a safety comment on the preceding line",
+                    );
+                }
+            }
+        }
+    }
 }
 
 fn is_unsafe_from_proc_macro(cx: &LateContext<'_>, block: &Block<'_>) -> bool {

tests/ui/undocumented_unsafe_blocks.rs

@@ -1,7 +1,7 @@
 // aux-build:proc_macro_unsafe.rs
 
 #![warn(clippy::undocumented_unsafe_blocks)]
-#![allow(clippy::let_unit_value)]
+#![allow(clippy::let_unit_value, clippy::missing_safety_doc)]
 
 extern crate proc_macro_unsafe;
 
@@ -334,4 +334,103 @@ pub fn print_binary_tree() {
     println!("{}", unsafe { String::from_utf8_unchecked(vec![]) });
 }
 
+mod unsafe_impl_smoke_test {
+    unsafe trait A {}
+
+    // error: no safety comment
+    unsafe impl A for () {}
+
+    // Safety: ok
+    unsafe impl A for (i32) {}
+
+    mod sub_mod {
+        // error: also works for the first item
+        unsafe impl B for (u32) {}
+        unsafe trait B {}
+    }
+
+    #[rustfmt::skip]
+    mod sub_mod2 {
+        // 
+        // SAFETY: ok
+        // 
+
+        unsafe impl B for (u32) {}
+        unsafe trait B {}
+    }
+}
+
+mod unsafe_impl_from_macro {
+    unsafe trait T {}
+
+    macro_rules! unsafe_impl {
+        ($t:ty) => {
+            unsafe impl T for $t {}
+        };
+    }
+    // ok: from macro expanision
+    unsafe_impl!(());
+    // ok: from macro expansion
+    unsafe_impl!(i32);
+}
+
+#[rustfmt::skip]
+mod unsafe_impl_valid_comment {
+    unsafe trait SaFety {}
+    // SaFety:
+    unsafe impl SaFety for () {}
+
+    unsafe trait MultiLineComment {}
+    // The following impl is safe
+    // ...
+    // Safety: reason
+    unsafe impl MultiLineComment for () {}
+
+    unsafe trait NoAscii {}
+    // 安全 SAFETY: 以下のコードは安全です
+    unsafe impl NoAscii for () {}
+
+    unsafe trait InlineAndPrecedingComment {}
+    // SAFETY:
+    /* comment */ unsafe impl InlineAndPrecedingComment for () {}
+
+    unsafe trait BuriedSafety {}
+    // 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 impl BuriedSafety for () {}
+
+    unsafe trait MultiLineBlockComment {}
+    /* This is a description
+     * Safety: */
+    unsafe impl MultiLineBlockComment for () {}
+}
+
+#[rustfmt::skip]
+mod unsafe_impl_invalid_comment {
+    unsafe trait NoComment {}
+
+    unsafe impl NoComment for () {}
+
+    unsafe trait InlineComment {}
+
+    /* SAFETY: */ unsafe impl InlineComment for () {}
+
+    unsafe trait TrailingComment {}
+
+    unsafe impl TrailingComment for () {} // SAFETY:
+
+    unsafe trait Interference {}
+    // SAFETY:
+    const BIG_NUMBER: i32 = 1000000;
+    unsafe impl Interference for () {}
+}
+
 fn main() {}

tests/ui/undocumented_unsafe_blocks.stderr

@@ -147,5 +147,53 @@ LL |     println!("{}", unsafe { String::from_utf8_unchecked(vec![]) });
    |
    = help: consider adding a safety comment on the preceding line
 
-error: aborting due to 18 previous errors
+error: unsafe impl missing a safety comment
+  --> $DIR/undocumented_unsafe_blocks.rs:341:5
+   |
+LL |     unsafe impl A for () {}
+   |     ^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = help: consider adding a safety comment on the preceding line
+
+error: unsafe impl missing a safety comment
+  --> $DIR/undocumented_unsafe_blocks.rs:348:9
+   |
+LL |         unsafe impl B for (u32) {}
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = help: consider adding a safety comment on the preceding line
+
+error: unsafe impl missing a safety comment
+  --> $DIR/undocumented_unsafe_blocks.rs:420:5
+   |
+LL |     unsafe impl NoComment for () {}
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = help: consider adding a safety comment on the preceding line
+
+error: unsafe impl missing a safety comment
+  --> $DIR/undocumented_unsafe_blocks.rs:424:19
+   |
+LL |     /* SAFETY: */ unsafe impl InlineComment for () {}
+   |                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = help: consider adding a safety comment on the preceding line
+
+error: unsafe impl missing a safety comment
+  --> $DIR/undocumented_unsafe_blocks.rs:428:5
+   |
+LL |     unsafe impl TrailingComment for () {} // SAFETY:
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = help: consider adding a safety comment on the preceding line
+
+error: unsafe impl missing a safety comment
+  --> $DIR/undocumented_unsafe_blocks.rs:433:5
+   |
+LL |     unsafe impl Interference for () {}
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = help: consider adding a safety comment on the preceding line
+
+error: aborting due to 24 previous errors