have a condition for has_break_or_return in WHILE_IMMUTABLE_CONDITION lint

Author: yerke

clippy_lints/src/loops.rs

@@ -2374,13 +2374,20 @@ fn check_infinite_loop<'a, 'tcx>(cx: &LateContext<'a, 'tcx>, cond: &'tcx Expr, e
     has_break_or_return_visitor.visit_expr(expr);
     let has_break_or_return = has_break_or_return_visitor.has_break_or_return;
 
-    if no_cond_variable_mutated && !mutable_static_in_cond && !has_break_or_return {
-        span_lint(
+    if no_cond_variable_mutated && !mutable_static_in_cond {
+        span_lint_and_then(
             cx,
             WHILE_IMMUTABLE_CONDITION,
             cond.span,
-            "variables in the condition are not mutated in the loop body. \
-             This may lead to an infinite or to a never running loop",
+            "variables in the condition are not mutated in the loop body",
+            |db| {
+                db.note("This may lead to an infinite or to a never running loop");
+
+                if has_break_or_return {
+                    db.note("this loop contains `return`s or `break`s");
+                    db.help("rewrite it as `if cond { loop { } }`");
+                }
+            },
         );
     }
 }

tests/ui/infinite_loop.rs

@@ -183,14 +183,14 @@ fn while_loop_with_break_and_return() {
         if y == 0 {
             break;
         }
-        println!("OK - loop contains break");
+        println!("KO - loop contains break");
     }
 
     while y < 10 {
         if y == 0 {
             return;
         }
-        println!("OK - loop contains return");
+        println!("KO - loop contains return");
     }
 }
 

tests/ui/infinite_loop.stderr

@@ -1,58 +1,95 @@
-error: variables in the condition are not mutated in the loop body. This may lead to an infinite or to a never running loop
+error: variables in the condition are not mutated in the loop body
   --> $DIR/infinite_loop.rs:23:11
    |
 LL |     while y < 10 {
    |           ^^^^^^
    |
    = note: `#[deny(clippy::while_immutable_condition)]` on by default
+   = note: This may lead to an infinite or to a never running loop
 
-error: variables in the condition are not mutated in the loop body. This may lead to an infinite or to a never running loop
+error: variables in the condition are not mutated in the loop body
   --> $DIR/infinite_loop.rs:28:11
    |
 LL |     while y < 10 && x < 3 {
    |           ^^^^^^^^^^^^^^^
+   |
+   = note: This may lead to an infinite or to a never running loop
 
-error: variables in the condition are not mutated in the loop body. This may lead to an infinite or to a never running loop
+error: variables in the condition are not mutated in the loop body
   --> $DIR/infinite_loop.rs:35:11
    |
 LL |     while !cond {
    |           ^^^^^
+   |
+   = note: This may lead to an infinite or to a never running loop
 
-error: variables in the condition are not mutated in the loop body. This may lead to an infinite or to a never running loop
+error: variables in the condition are not mutated in the loop body
   --> $DIR/infinite_loop.rs:79:11
    |
 LL |     while i < 3 {
    |           ^^^^^
+   |
+   = note: This may lead to an infinite or to a never running loop
 
-error: variables in the condition are not mutated in the loop body. This may lead to an infinite or to a never running loop
+error: variables in the condition are not mutated in the loop body
   --> $DIR/infinite_loop.rs:84:11
    |
 LL |     while i < 3 && j > 0 {
    |           ^^^^^^^^^^^^^^
+   |
+   = note: This may lead to an infinite or to a never running loop
 
-error: variables in the condition are not mutated in the loop body. This may lead to an infinite or to a never running loop
+error: variables in the condition are not mutated in the loop body
   --> $DIR/infinite_loop.rs:88:11
    |
 LL |     while i < 3 {
    |           ^^^^^
+   |
+   = note: This may lead to an infinite or to a never running loop
 
-error: variables in the condition are not mutated in the loop body. This may lead to an infinite or to a never running loop
+error: variables in the condition are not mutated in the loop body
   --> $DIR/infinite_loop.rs:103:11
    |
 LL |     while i < 3 {
    |           ^^^^^
+   |
+   = note: This may lead to an infinite or to a never running loop
 
-error: variables in the condition are not mutated in the loop body. This may lead to an infinite or to a never running loop
+error: variables in the condition are not mutated in the loop body
   --> $DIR/infinite_loop.rs:108:11
    |
 LL |     while i < 3 {
    |           ^^^^^
+   |
+   = note: This may lead to an infinite or to a never running loop
 
-error: variables in the condition are not mutated in the loop body. This may lead to an infinite or to a never running loop
+error: variables in the condition are not mutated in the loop body
   --> $DIR/infinite_loop.rs:174:15
    |
 LL |         while self.count < n {
    |               ^^^^^^^^^^^^^^
+   |
+   = note: This may lead to an infinite or to a never running loop
+
+error: variables in the condition are not mutated in the loop body
+  --> $DIR/infinite_loop.rs:182:11
+   |
+LL |     while y < 10 {
+   |           ^^^^^^
+   |
+   = note: This may lead to an infinite or to a never running loop
+   = note: this loop contains `return`s or `break`s
+   = help: rewrite it as `if cond { loop { } }`
+
+error: variables in the condition are not mutated in the loop body
+  --> $DIR/infinite_loop.rs:189:11
+   |
+LL |     while y < 10 {
+   |           ^^^^^^
+   |
+   = note: This may lead to an infinite or to a never running loop
+   = note: this loop contains `return`s or `break`s
+   = help: rewrite it as `if cond { loop { } }`
 
-error: aborting due to 9 previous errors
+error: aborting due to 11 previous errors