Auto merge of rust-lang#11170 - tgross35:undocumented-unsafe-blocks-defaults, r=Centri3

Change defaults of `accept-comment-above-statement` and `accept-comment-above-attributes`

This patch sets the two configuration options for `undocumented_unsafe_blocks` to `true` by default: these are `accept-comment-above-statement` and `accept-comment-above-attributes`. Having these values `false` by default prevents what many users would consider clean code, e.g. placing the `// SAFETY:` comment above a single-line functino call, rather than directly next to the argument.

This was originally discussed in rust-lang/rust-clippy#11162

changelog: [`undocumented_unsafe_blocks`]: set
`accept-comment-above-statement` and `accept-comment-above-attributes` to `true` by default.

Author: bors

book/src/lint_configuration.md

@@ -703,7 +703,7 @@ Minimum chars an ident can have, anything below or equal to this will be linted.
 ## `accept-comment-above-statement`
 Whether to accept a safety comment to be placed above the statement containing the `unsafe` block
 
-**Default Value:** `false` (`bool`)
+**Default Value:** `true` (`bool`)
 
 ---
 **Affected lints:**
@@ -713,7 +713,7 @@ Whether to accept a safety comment to be placed above the statement containing t
 ## `accept-comment-above-attributes`
 Whether to accept a safety comment to be placed above the attributes for the `unsafe` block
 
-**Default Value:** `false` (`bool`)
+**Default Value:** `true` (`bool`)
 
 ---
 **Affected lints:**

clippy_lints/src/utils/conf.rs

@@ -542,11 +542,11 @@ define_Conf! {
     /// Lint: UNDOCUMENTED_UNSAFE_BLOCKS.
     ///
     /// Whether to accept a safety comment to be placed above the statement containing the `unsafe` block
-    (accept_comment_above_statement: bool = false),
+    (accept_comment_above_statement: bool = true),
     /// Lint: UNDOCUMENTED_UNSAFE_BLOCKS.
     ///
     /// Whether to accept a safety comment to be placed above the attributes for the `unsafe` block
-    (accept_comment_above_attributes: bool = false),
+    (accept_comment_above_attributes: bool = true),
     /// Lint: UNNECESSARY_RAW_STRING_HASHES.
     ///
     /// Whether to allow `r#""#` when `r""` can be used

tests/ui-toml/undocumented_unsafe_blocks/clippy.toml

@@ -0,0 +1,2 @@
+# default configuration has `accept-comment-above-statement` and
+# `accept-comment-above-attributes` true

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

@@ -0,0 +1,3 @@
+# test with these options disabled
+accept-comment-above-statement = false
+accept-comment-above-attributes = false

tests/ui-toml/undocumented_unsafe_blocks/disabled/clippy.toml

@@ -1,5 +1,5 @@
 error: unsafe block missing a safety comment
-  --> $DIR/undocumented_unsafe_blocks.rs:263:19
+  --> $DIR/undocumented_unsafe_blocks.rs:266:19
    |
 LL |     /* Safety: */ unsafe {}
    |                   ^^^^^^^^^
@@ -9,103 +9,103 @@ LL |     /* Safety: */ unsafe {}
    = help: to override `-D warnings` add `#[allow(clippy::undocumented_unsafe_blocks)]`
 
 error: unsafe block missing a safety comment
-  --> $DIR/undocumented_unsafe_blocks.rs:267:5
+  --> $DIR/undocumented_unsafe_blocks.rs:270:5
    |
 LL |     unsafe {}
    |     ^^^^^^^^^
    |
    = help: consider adding a safety comment on the preceding line
 
 error: unsafe block missing a safety comment
-  --> $DIR/undocumented_unsafe_blocks.rs:271:14
+  --> $DIR/undocumented_unsafe_blocks.rs:274:14
    |
 LL |     let _ = [unsafe { 14 }, unsafe { 15 }, 42, unsafe { 16 }];
    |              ^^^^^^^^^^^^^
    |
    = help: consider adding a safety comment on the preceding line
 
 error: unsafe block missing a safety comment
-  --> $DIR/undocumented_unsafe_blocks.rs:271:29
+  --> $DIR/undocumented_unsafe_blocks.rs:274:29
    |
 LL |     let _ = [unsafe { 14 }, unsafe { 15 }, 42, unsafe { 16 }];
    |                             ^^^^^^^^^^^^^
    |
    = help: consider adding a safety comment on the preceding line
 
 error: unsafe block missing a safety comment
-  --> $DIR/undocumented_unsafe_blocks.rs:271:48
+  --> $DIR/undocumented_unsafe_blocks.rs:274:48
    |
 LL |     let _ = [unsafe { 14 }, unsafe { 15 }, 42, unsafe { 16 }];
    |                                                ^^^^^^^^^^^^^
    |
    = help: consider adding a safety comment on the preceding line
 
 error: unsafe block missing a safety comment
-  --> $DIR/undocumented_unsafe_blocks.rs:275:18
+  --> $DIR/undocumented_unsafe_blocks.rs:278:18
    |
 LL |     let _ = (42, unsafe {}, "test", unsafe {});
    |                  ^^^^^^^^^
    |
    = help: consider adding a safety comment on the preceding line
 
 error: unsafe block missing a safety comment
-  --> $DIR/undocumented_unsafe_blocks.rs:275:37
+  --> $DIR/undocumented_unsafe_blocks.rs:278:37
    |
 LL |     let _ = (42, unsafe {}, "test", unsafe {});
    |                                     ^^^^^^^^^
    |
    = help: consider adding a safety comment on the preceding line
 
 error: unsafe block missing a safety comment
-  --> $DIR/undocumented_unsafe_blocks.rs:279:14
+  --> $DIR/undocumented_unsafe_blocks.rs:282:14
    |
 LL |     let _ = *unsafe { &42 };
    |              ^^^^^^^^^^^^^^
    |
    = help: consider adding a safety comment on the preceding line
 
 error: unsafe block missing a safety comment
-  --> $DIR/undocumented_unsafe_blocks.rs:284:19
+  --> $DIR/undocumented_unsafe_blocks.rs:287:19
    |
 LL |     let _ = match unsafe {} {
    |                   ^^^^^^^^^
    |
    = help: consider adding a safety comment on the preceding line
 
 error: unsafe block missing a safety comment
-  --> $DIR/undocumented_unsafe_blocks.rs:290:14
+  --> $DIR/undocumented_unsafe_blocks.rs:293:14
    |
 LL |     let _ = &unsafe {};
    |              ^^^^^^^^^
    |
    = help: consider adding a safety comment on the preceding line
 
 error: unsafe block missing a safety comment
-  --> $DIR/undocumented_unsafe_blocks.rs:294:14
+  --> $DIR/undocumented_unsafe_blocks.rs:297:14
    |
 LL |     let _ = [unsafe {}; 5];
    |              ^^^^^^^^^
    |
    = help: consider adding a safety comment on the preceding line
 
 error: unsafe block missing a safety comment
-  --> $DIR/undocumented_unsafe_blocks.rs:298:13
+  --> $DIR/undocumented_unsafe_blocks.rs:301:13
    |
 LL |     let _ = unsafe {};
    |             ^^^^^^^^^
    |
    = help: consider adding a safety comment on the preceding line
 
 error: unsafe block missing a safety comment
-  --> $DIR/undocumented_unsafe_blocks.rs:308:8
+  --> $DIR/undocumented_unsafe_blocks.rs:311:8
    |
 LL |     t!(unsafe {});
    |        ^^^^^^^^^
    |
    = help: consider adding a safety comment on the preceding line
 
 error: unsafe block missing a safety comment
-  --> $DIR/undocumented_unsafe_blocks.rs:314:13
+  --> $DIR/undocumented_unsafe_blocks.rs:317:13
    |
 LL |             unsafe {}
    |             ^^^^^^^^^
@@ -117,55 +117,55 @@ LL |     t!();
    = 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:322:5
+  --> $DIR/undocumented_unsafe_blocks.rs:325:5
    |
 LL |     unsafe {} // SAFETY:
    |     ^^^^^^^^^
    |
    = help: consider adding a safety comment on the preceding line
 
 error: unsafe block missing a safety comment
-  --> $DIR/undocumented_unsafe_blocks.rs:326:5
+  --> $DIR/undocumented_unsafe_blocks.rs:329:5
    |
 LL |     unsafe {
    |     ^^^^^^^^
    |
    = help: consider adding a safety comment on the preceding line
 
 error: unsafe block missing a safety comment
-  --> $DIR/undocumented_unsafe_blocks.rs:336:5
+  --> $DIR/undocumented_unsafe_blocks.rs:339:5
    |
 LL |     unsafe {};
    |     ^^^^^^^^^
    |
    = help: consider adding a safety comment on the preceding line
 
 error: unsafe block missing a safety comment
-  --> $DIR/undocumented_unsafe_blocks.rs:340:20
+  --> $DIR/undocumented_unsafe_blocks.rs:343:20
    |
 LL |     println!("{}", unsafe { String::from_utf8_unchecked(vec![]) });
    |                    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = help: consider adding a safety comment on the preceding line
 
 error: unsafe impl missing a safety comment
-  --> $DIR/undocumented_unsafe_blocks.rs:347:5
+  --> $DIR/undocumented_unsafe_blocks.rs:350:5
    |
 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:354:9
+  --> $DIR/undocumented_unsafe_blocks.rs:357:9
    |
 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:375:13
+  --> $DIR/undocumented_unsafe_blocks.rs:378:13
    |
 LL |             unsafe impl T for $t {}
    |             ^^^^^^^^^^^^^^^^^^^^^^^
@@ -177,7 +177,7 @@ LL |     no_safety_comment!(());
    = note: this error originates in the macro `no_safety_comment` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error: unsafe impl missing a safety comment
-  --> $DIR/undocumented_unsafe_blocks.rs:400:13
+  --> $DIR/undocumented_unsafe_blocks.rs:403:13
    |
 LL |             unsafe impl T for $t {}
    |             ^^^^^^^^^^^^^^^^^^^^^^^
@@ -189,15 +189,15 @@ LL |     no_safety_comment!(());
    = note: this error originates in the macro `no_safety_comment` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error: unsafe impl missing a safety comment
-  --> $DIR/undocumented_unsafe_blocks.rs:408:5
+  --> $DIR/undocumented_unsafe_blocks.rs:411:5
    |
 LL |     unsafe impl T for (i32) {}
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = help: consider adding a safety comment on the preceding line
 
 error: unsafe impl missing a safety comment
-  --> $DIR/undocumented_unsafe_blocks.rs:400:13
+  --> $DIR/undocumented_unsafe_blocks.rs:403:13
    |
 LL |             unsafe impl T for $t {}
    |             ^^^^^^^^^^^^^^^^^^^^^^^
@@ -209,77 +209,77 @@ LL |     no_safety_comment!(u32);
    = note: this error originates in the macro `no_safety_comment` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error: unsafe impl missing a safety comment
-  --> $DIR/undocumented_unsafe_blocks.rs:414:5
+  --> $DIR/undocumented_unsafe_blocks.rs:417:5
    |
 LL |     unsafe impl T for (bool) {}
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = help: consider adding a safety comment on the preceding line
 
 error: unsafe impl missing a safety comment
-  --> $DIR/undocumented_unsafe_blocks.rs:460:5
+  --> $DIR/undocumented_unsafe_blocks.rs:463:5
    |
 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:464:19
+  --> $DIR/undocumented_unsafe_blocks.rs:467:19
    |
 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:468:5
+  --> $DIR/undocumented_unsafe_blocks.rs:471:5
    |
 LL |     unsafe impl TrailingComment for () {} // SAFETY:
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = help: consider adding a safety comment on the preceding line
 
 error: constant item has unnecessary safety comment
-  --> $DIR/undocumented_unsafe_blocks.rs:472:5
+  --> $DIR/undocumented_unsafe_blocks.rs:475:5
    |
 LL |     const BIG_NUMBER: i32 = 1000000;
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
 help: consider removing the safety comment
-  --> $DIR/undocumented_unsafe_blocks.rs:471:5
+  --> $DIR/undocumented_unsafe_blocks.rs:474:5
    |
 LL |     // SAFETY:
    |     ^^^^^^^^^^
    = note: `-D clippy::unnecessary-safety-comment` implied by `-D warnings`
    = help: to override `-D warnings` add `#[allow(clippy::unnecessary_safety_comment)]`
 
 error: unsafe impl missing a safety comment
-  --> $DIR/undocumented_unsafe_blocks.rs:473:5
+  --> $DIR/undocumented_unsafe_blocks.rs:476:5
    |
 LL |     unsafe impl Interference for () {}
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = help: consider adding a safety comment on the preceding line
 
 error: unsafe impl missing a safety comment
-  --> $DIR/undocumented_unsafe_blocks.rs:480:5
+  --> $DIR/undocumented_unsafe_blocks.rs:483:5
    |
 LL |     unsafe impl ImplInFn for () {}
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = help: consider adding a safety comment on the preceding line
 
 error: unsafe impl missing a safety comment
-  --> $DIR/undocumented_unsafe_blocks.rs:489:1
+  --> $DIR/undocumented_unsafe_blocks.rs:492:1
    |
 LL | unsafe impl CrateRoot for () {}
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = help: consider adding a safety comment on the preceding line
 
 error: statement has unnecessary safety comment
-  --> $DIR/undocumented_unsafe_blocks.rs:502:5
+  --> $DIR/undocumented_unsafe_blocks.rs:505:5
    |
 LL | /     let _ = {
 LL | |         if unsafe { true } {
@@ -291,21 +291,21 @@ LL | |     };
    | |______^
    |
 help: consider removing the safety comment
-  --> $DIR/undocumented_unsafe_blocks.rs:501:5
+  --> $DIR/undocumented_unsafe_blocks.rs:504:5
    |
 LL |     // SAFETY: this is more than one level away, so it should warn
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: unsafe block missing a safety comment
-  --> $DIR/undocumented_unsafe_blocks.rs:503:12
+  --> $DIR/undocumented_unsafe_blocks.rs:506:12
    |
 LL |         if unsafe { true } {
    |            ^^^^^^^^^^^^^^^
    |
    = help: consider adding a safety comment on the preceding line
 
 error: unsafe block missing a safety comment
-  --> $DIR/undocumented_unsafe_blocks.rs:506:23
+  --> $DIR/undocumented_unsafe_blocks.rs:509:23
    |
 LL |             let bar = unsafe {};
    |                       ^^^^^^^^^