[unnecessary_safety_comment] Some fixes regarding comments above attributes (rust-lang#15678)

The way clippy checked for SAFETY comments above attributes was wrong:
- It wasn't considered for items
- It cause an ICE with some attributes
- When considering comments above attributes, it didn't considered
comments below them, causing some unlintable situations.

This PR tries to fix this by delegating the skipping of attributes to
the function analyzing the source code itself.

changelog: [`unnecessary_safety_comment`]: Taking into account comments
above attributes for items

Fixes rust-lang#14555
Fixes rust-lang#15684
Fixes rust-lang#15754

Author: blyxyas

clippy_lints/src/undocumented_unsafe_blocks.rs

@@ -5,10 +5,10 @@ error: module has unnecessary safety comment
   | ^^^^^^^^
   |
 help: consider removing the safety comment
- --> src/main.rs:1:1
+ --> src/main.rs:1:4
   |
 1 | // SAFETY: ...
-  | ^^^^^^^^^^^^^^
+  |    ^^^^^^^
   = note: requested on the command line with `-D clippy::unnecessary-safety-comment`
 
 error: module has unnecessary safety comment
@@ -18,9 +18,9 @@ error: module has unnecessary safety comment
   | ^^^^^^^^
   |
 help: consider removing the safety comment
- --> src/main.rs:4:1
+ --> src/main.rs:4:4
   |
 4 | // SAFETY: ...
-  | ^^^^^^^^^^^^^^
+  |    ^^^^^^^
 
 error: could not compile `undocumented_unsafe_blocks` (bin "undocumented_unsafe_blocks") due to 2 previous errors

tests/ui-cargo/undocumented_unsafe_blocks/fail/Cargo.stderr

@@ -247,10 +247,10 @@ LL |     const BIG_NUMBER: i32 = 1000000;
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
 help: consider removing the safety comment
-  --> tests/ui-toml/undocumented_unsafe_blocks/undocumented_unsafe_blocks.rs:507:5
+  --> tests/ui-toml/undocumented_unsafe_blocks/undocumented_unsafe_blocks.rs:507:8
    |
 LL |     // SAFETY:
-   |     ^^^^^^^^^^
+   |        ^^^^^^^
    = note: `-D clippy::unnecessary-safety-comment` implied by `-D warnings`
    = help: to override `-D warnings` add `#[allow(clippy::unnecessary_safety_comment)]`
 
@@ -289,10 +289,10 @@ LL | |     };
    | |______^
    |
 help: consider removing the safety comment
-  --> tests/ui-toml/undocumented_unsafe_blocks/undocumented_unsafe_blocks.rs:542:5
+  --> tests/ui-toml/undocumented_unsafe_blocks/undocumented_unsafe_blocks.rs:542:8
    |
 LL |     // SAFETY: this is more than one level away, so it should warn
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: unsafe block missing a safety comment
   --> tests/ui-toml/undocumented_unsafe_blocks/undocumented_unsafe_blocks.rs:545:12
@@ -342,17 +342,137 @@ LL |         const NO_SAFETY_IN_IMPL: i32 = unsafe { 1 };
    |
    = help: consider adding a safety comment on the preceding line
 
+error: constant has unnecessary safety comment
+  --> tests/ui-toml/undocumented_unsafe_blocks/undocumented_unsafe_blocks.rs:701:5
+   |
+LL |     const UNIX_EPOCH_JULIAN_DAY: i32 =
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+help: consider removing the safety comment
+  --> tests/ui-toml/undocumented_unsafe_blocks/undocumented_unsafe_blocks.rs:699:8
+   |
+LL |     // SAFETY: fail ONLY if `accept-comment-above-attribute = false`
+   |        ^^^^^^^
+
 error: statement has unnecessary safety comment
-  --> tests/ui-toml/undocumented_unsafe_blocks/undocumented_unsafe_blocks.rs:719:5
+  --> tests/ui-toml/undocumented_unsafe_blocks/undocumented_unsafe_blocks.rs:721:5
    |
 LL |     _ = bar();
    |     ^^^^^^^^^^
    |
 help: consider removing the safety comment
-  --> tests/ui-toml/undocumented_unsafe_blocks/undocumented_unsafe_blocks.rs:718:5
+  --> tests/ui-toml/undocumented_unsafe_blocks/undocumented_unsafe_blocks.rs:720:8
    |
 LL |     // SAFETY: unnecessary_safety_comment triggers here
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: module has unnecessary safety comment
+  --> tests/ui-toml/undocumented_unsafe_blocks/undocumented_unsafe_blocks.rs:741:5
+   |
+LL |     mod x {}
+   |     ^^^^^^^^
+   |
+help: consider removing the safety comment
+  --> tests/ui-toml/undocumented_unsafe_blocks/undocumented_unsafe_blocks.rs:740:8
+   |
+LL |     // SAFETY: ...
+   |        ^^^^^^^
+
+error: module has unnecessary safety comment
+  --> tests/ui-toml/undocumented_unsafe_blocks/undocumented_unsafe_blocks.rs:746:5
+   |
+LL |     mod y {}
+   |     ^^^^^^^^
+   |
+help: consider removing the safety comment
+  --> tests/ui-toml/undocumented_unsafe_blocks/undocumented_unsafe_blocks.rs:744:8
+   |
+LL |     // SAFETY: ...
+   |        ^^^^^^^
+
+error: module has unnecessary safety comment
+  --> tests/ui-toml/undocumented_unsafe_blocks/undocumented_unsafe_blocks.rs:751:5
+   |
+LL |     mod z {}
+   |     ^^^^^^^^
+   |
+help: consider removing the safety comment
+  --> tests/ui-toml/undocumented_unsafe_blocks/undocumented_unsafe_blocks.rs:750:8
+   |
+LL |     // SAFETY: ...
+   |        ^^^^^^^
+
+error: module has unnecessary safety comment
+  --> tests/ui-toml/undocumented_unsafe_blocks/undocumented_unsafe_blocks.rs:759:5
+   |
+LL |     mod y {}
+   |     ^^^^^^^^
+   |
+help: consider removing the safety comment
+  --> tests/ui-toml/undocumented_unsafe_blocks/undocumented_unsafe_blocks.rs:757:8
+   |
+LL |     // SAFETY: ...
+   |        ^^^^^^^
+
+error: statement has unnecessary safety comment
+  --> tests/ui-toml/undocumented_unsafe_blocks/undocumented_unsafe_blocks.rs:774:9
+   |
+LL |         let x = 34;
+   |         ^^^^^^^^^^^
+   |
+help: consider removing the safety comment
+  --> tests/ui-toml/undocumented_unsafe_blocks/undocumented_unsafe_blocks.rs:772:12
+   |
+LL |         // SAFETY: ...
+   |            ^^^^^^^^^^^
+
+error: function has unnecessary safety comment
+  --> tests/ui-toml/undocumented_unsafe_blocks/undocumented_unsafe_blocks.rs:781:5
+   |
+LL |     unsafe fn unsafe_comment() {}
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+help: consider changing the `safety` comment for a `# Safety` doc comment
+  --> tests/ui-toml/undocumented_unsafe_blocks/undocumented_unsafe_blocks.rs:780:8
+   |
+LL |     // SAFETY: Bla
+   |        ^^^^^^^
+
+error: function has unnecessary safety comment
+  --> tests/ui-toml/undocumented_unsafe_blocks/undocumented_unsafe_blocks.rs:787:5
+   |
+LL |     unsafe fn unsafe_block_comment() {}
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+help: consider changing the `safety` comment for a `# Safety` doc comment
+  --> tests/ui-toml/undocumented_unsafe_blocks/undocumented_unsafe_blocks.rs:785:8
+   |
+LL |        SAFETY: Bla
+   |        ^^^^^^^
+
+error: function has unnecessary safety comment
+  --> tests/ui-toml/undocumented_unsafe_blocks/undocumented_unsafe_blocks.rs:791:5
+   |
+LL |     fn safe_comment() {}
+   |     ^^^^^^^^^^^^^^^^^^^^
+   |
+help: consider removing the safety comment
+  --> tests/ui-toml/undocumented_unsafe_blocks/undocumented_unsafe_blocks.rs:790:8
+   |
+LL |     // SAFETY: Bla
+   |        ^^^^^^^
+
+error: function has unnecessary safety comment
+  --> tests/ui-toml/undocumented_unsafe_blocks/undocumented_unsafe_blocks.rs:795:5
+   |
+LL |     fn safe_doc_comment() {}
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+help: consider removing the safety comment
+  --> tests/ui-toml/undocumented_unsafe_blocks/undocumented_unsafe_blocks.rs:794:9
+   |
+LL |     /// SAFETY: Bla
+   |         ^^^^^^^
 
-error: aborting due to 40 previous errors
+error: aborting due to 50 previous errors
 

tests/ui-toml/undocumented_unsafe_blocks/undocumented_unsafe_blocks.default.stderr

@@ -247,10 +247,10 @@ LL |     const BIG_NUMBER: i32 = 1000000;
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
 help: consider removing the safety comment
-  --> tests/ui-toml/undocumented_unsafe_blocks/undocumented_unsafe_blocks.rs:507:5
+  --> tests/ui-toml/undocumented_unsafe_blocks/undocumented_unsafe_blocks.rs:507:8
    |
 LL |     // SAFETY:
-   |     ^^^^^^^^^^
+   |        ^^^^^^^
    = note: `-D clippy::unnecessary-safety-comment` implied by `-D warnings`
    = help: to override `-D warnings` add `#[allow(clippy::unnecessary_safety_comment)]`
 
@@ -297,10 +297,10 @@ LL | |     };
    | |______^
    |
 help: consider removing the safety comment
-  --> tests/ui-toml/undocumented_unsafe_blocks/undocumented_unsafe_blocks.rs:542:5
+  --> tests/ui-toml/undocumented_unsafe_blocks/undocumented_unsafe_blocks.rs:542:8
    |
 LL |     // SAFETY: this is more than one level away, so it should warn
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: unsafe block missing a safety comment
   --> tests/ui-toml/undocumented_unsafe_blocks/undocumented_unsafe_blocks.rs:545:12
@@ -439,24 +439,104 @@ LL |         unsafe { Date::__from_ordinal_date_unchecked(1970, 1) }.into_julian
    = help: consider adding a safety comment on the preceding line
 
 error: statement has unnecessary safety comment
-  --> tests/ui-toml/undocumented_unsafe_blocks/undocumented_unsafe_blocks.rs:719:5
+  --> tests/ui-toml/undocumented_unsafe_blocks/undocumented_unsafe_blocks.rs:721:5
    |
 LL |     _ = bar();
    |     ^^^^^^^^^^
    |
 help: consider removing the safety comment
-  --> tests/ui-toml/undocumented_unsafe_blocks/undocumented_unsafe_blocks.rs:718:5
+  --> tests/ui-toml/undocumented_unsafe_blocks/undocumented_unsafe_blocks.rs:720:8
    |
 LL |     // SAFETY: unnecessary_safety_comment triggers here
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: unsafe block missing a safety comment
-  --> tests/ui-toml/undocumented_unsafe_blocks/undocumented_unsafe_blocks.rs:733:12
+  --> tests/ui-toml/undocumented_unsafe_blocks/undocumented_unsafe_blocks.rs:735:12
    |
 LL |     return unsafe { h() };
    |            ^^^^^^^^^^^^^^
    |
    = help: consider adding a safety comment on the preceding line
 
-error: aborting due to 53 previous errors
+error: module has unnecessary safety comment
+  --> tests/ui-toml/undocumented_unsafe_blocks/undocumented_unsafe_blocks.rs:741:5
+   |
+LL |     mod x {}
+   |     ^^^^^^^^
+   |
+help: consider removing the safety comment
+  --> tests/ui-toml/undocumented_unsafe_blocks/undocumented_unsafe_blocks.rs:740:8
+   |
+LL |     // SAFETY: ...
+   |        ^^^^^^^
+
+error: module has unnecessary safety comment
+  --> tests/ui-toml/undocumented_unsafe_blocks/undocumented_unsafe_blocks.rs:751:5
+   |
+LL |     mod z {}
+   |     ^^^^^^^^
+   |
+help: consider removing the safety comment
+  --> tests/ui-toml/undocumented_unsafe_blocks/undocumented_unsafe_blocks.rs:750:8
+   |
+LL |     // SAFETY: ...
+   |        ^^^^^^^
+
+error: unsafe block missing a safety comment
+  --> tests/ui-toml/undocumented_unsafe_blocks/undocumented_unsafe_blocks.rs:766:9
+   |
+LL |         unsafe {}
+   |         ^^^^^^^^^
+   |
+   = help: consider adding a safety comment on the preceding line
+
+error: function has unnecessary safety comment
+  --> tests/ui-toml/undocumented_unsafe_blocks/undocumented_unsafe_blocks.rs:781:5
+   |
+LL |     unsafe fn unsafe_comment() {}
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+help: consider changing the `safety` comment for a `# Safety` doc comment
+  --> tests/ui-toml/undocumented_unsafe_blocks/undocumented_unsafe_blocks.rs:780:8
+   |
+LL |     // SAFETY: Bla
+   |        ^^^^^^^
+
+error: function has unnecessary safety comment
+  --> tests/ui-toml/undocumented_unsafe_blocks/undocumented_unsafe_blocks.rs:787:5
+   |
+LL |     unsafe fn unsafe_block_comment() {}
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+help: consider changing the `safety` comment for a `# Safety` doc comment
+  --> tests/ui-toml/undocumented_unsafe_blocks/undocumented_unsafe_blocks.rs:785:8
+   |
+LL |        SAFETY: Bla
+   |        ^^^^^^^
+
+error: function has unnecessary safety comment
+  --> tests/ui-toml/undocumented_unsafe_blocks/undocumented_unsafe_blocks.rs:791:5
+   |
+LL |     fn safe_comment() {}
+   |     ^^^^^^^^^^^^^^^^^^^^
+   |
+help: consider removing the safety comment
+  --> tests/ui-toml/undocumented_unsafe_blocks/undocumented_unsafe_blocks.rs:790:8
+   |
+LL |     // SAFETY: Bla
+   |        ^^^^^^^
+
+error: function has unnecessary safety comment
+  --> tests/ui-toml/undocumented_unsafe_blocks/undocumented_unsafe_blocks.rs:795:5
+   |
+LL |     fn safe_doc_comment() {}
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+help: consider removing the safety comment
+  --> tests/ui-toml/undocumented_unsafe_blocks/undocumented_unsafe_blocks.rs:794:9
+   |
+LL |     /// SAFETY: Bla
+   |         ^^^^^^^
+
+error: aborting due to 60 previous errors