unnecessary_reserve: address review comments

Author: wowinter13

clippy_lints/src/unnecessary_reserve.rs

@@ -63,14 +63,21 @@ impl<'tcx> LateLintPass<'tcx> for UnnecessaryReserve {
             && let Some(next_stmt_span) = check_extend_method(cx, block, struct_calling_on, &args_a[0])
             && !next_stmt_span.from_expansion()
         {
+            let stmt_span = cx
+                .tcx
+                .hir()
+                .parent_id_iter(expr.hir_id)
+                .next()
+                .map_or(expr.span, |parent| cx.tcx.hir().span(parent));
+
             span_lint_and_then(
                 cx,
                 UNNECESSARY_RESERVE,
                 next_stmt_span,
                 "unnecessary call to `reserve`",
                 |diag| {
                     diag.span_suggestion(
-                        expr.span,
+                        stmt_span,
                         "remove this line",
                         String::new(),
                         Applicability::MaybeIncorrect,

tests/ui/unnecessary_reserve.fixed

@@ -8,7 +8,7 @@ fn main() {
     vec_reserve();
     vec_deque_reserve();
     hash_map_reserve();
-    msrv_1_62();
+    insufficient_msrv();
     box_vec_reserve();
 }
 
@@ -18,31 +18,36 @@ fn vec_reserve() {
     let array2: &[usize] = &[3, 4];
 
     // do not lint - different arrays
-    ;
+    
     vec.extend(array2);
 
     // do not lint
     vec.reserve(1);
     vec.extend([1]);
 
-    //// do lint
-    ;
+    // do lint
+    
     vec.extend(array1);
 
     // do lint
     {
-        ;
+        
         vec.extend(array1)
     };
 
     // do not lint
-    ;
+    
     vec.push(1);
     vec.extend(array1);
 
     // do not lint
     let mut other_vec: Vec<usize> = Vec::with_capacity(1);
-    vec.extend([1])
+    other_vec.extend([1]);
+
+    // do not lint
+    let mut vec2: Vec<usize> = vec![];
+    vec2.extend(array1);
+    vec2.reserve(array1.len());
 }
 
 fn vec_deque_reserve() {
@@ -54,7 +59,7 @@ fn vec_deque_reserve() {
     vec_deque.extend([1]);
 
     // do lint
-    ;
+    
     vec_deque.extend(array);
 
     // do not lint
@@ -82,8 +87,8 @@ fn hash_map_reserve() {
     map.extend(other_map);
 }
 
-fn msrv_1_62() {
-    #![clippy::msrv = "1.61"]
+#[clippy::msrv = "1.61"]
+fn insufficient_msrv() {
     let mut vec: Vec<usize> = vec![];
     let array: &[usize] = &[1, 2];
 
@@ -104,6 +109,6 @@ fn box_vec_reserve() {
     let array: &[usize] = &[1, 2];
 
     // do lint
-    ;
+    
     vec.extend(array);
 }

tests/ui/unnecessary_reserve.rs

@@ -8,7 +8,7 @@ fn main() {
     vec_reserve();
     vec_deque_reserve();
     hash_map_reserve();
-    msrv_1_62();
+    insufficient_msrv();
     box_vec_reserve();
 }
 
@@ -25,7 +25,7 @@ fn vec_reserve() {
     vec.reserve(1);
     vec.extend([1]);
 
-    //// do lint
+    // do lint
     vec.reserve(array1.len());
     vec.extend(array1);
 
@@ -43,7 +43,12 @@ fn vec_reserve() {
     // do not lint
     let mut other_vec: Vec<usize> = vec![];
     other_vec.reserve(1);
-    vec.extend([1])
+    other_vec.extend([1]);
+
+    // do not lint
+    let mut vec2: Vec<usize> = vec![];
+    vec2.extend(array1);
+    vec2.reserve(array1.len());
 }
 
 fn vec_deque_reserve() {
@@ -83,8 +88,8 @@ fn hash_map_reserve() {
     map.extend(other_map);
 }
 
-fn msrv_1_62() {
-    #![clippy::msrv = "1.61"]
+#[clippy::msrv = "1.61"]
+fn insufficient_msrv() {
     let mut vec: Vec<usize> = vec![];
     let array: &[usize] = &[1, 2];
 

tests/ui/unnecessary_reserve.stderr

@@ -16,9 +16,9 @@ LL | |     let array1: &[usize] = &[1, 2];
 LL | |     let array2: &[usize] = &[3, 4];
 ...  |
 LL | |     vec.reserve(array1.len());
-   | |     ------------------------- help: remove this line
+   | |     -------------------------- help: remove this line
 ...  |
-LL | |     vec.extend([1])
+LL | |     vec2.reserve(array1.len());
 LL | | }
    | |_^
    |
@@ -35,9 +35,9 @@ LL | |     let array1: &[usize] = &[1, 2];
 LL | |     let array2: &[usize] = &[3, 4];
 ...  |
 LL | |     vec.reserve(array1.len());
-   | |     ------------------------- help: remove this line
+   | |     -------------------------- help: remove this line
 ...  |
-LL | |     vec.extend([1])
+LL | |     vec2.reserve(array1.len());
 LL | | }
    | |_^
 
@@ -46,7 +46,7 @@ error: unnecessary call to `reserve`
    |
 LL | /     {
 LL | |         vec.reserve(array1.len());
-   | |         ------------------------- help: remove this line
+   | |         -------------------------- help: remove this line
 LL | |         vec.extend(array1)
 LL | |     };
    | |_____^
@@ -61,9 +61,9 @@ LL | |     let array1: &[usize] = &[1, 2];
 LL | |     let array2: &[usize] = &[3, 4];
 ...  |
 LL | |     vec.reserve(array1.len());
-   | |     ------------------------- help: remove this line
+   | |     -------------------------- help: remove this line
 ...  |
-LL | |     vec.extend([1])
+LL | |     vec2.reserve(array1.len());
 LL | | }
    | |_^
 
@@ -78,30 +78,30 @@ LL | |     other_vec.reserve(1);
    = help: to override `-D warnings` add `#[allow(clippy::reserve_after_initialization)]`
 
 error: unnecessary call to `reserve`
-  --> tests/ui/unnecessary_reserve.rs:49:24
+  --> tests/ui/unnecessary_reserve.rs:54:24
    |
 LL |   fn vec_deque_reserve() {
    |  ________________________^
 LL | |     let mut vec_deque: VecDeque<usize> = [1].into();
 LL | |     let array: &[usize] = &[1, 2];
 ...  |
 LL | |     vec_deque.reserve(array.len());
-   | |     ------------------------------ help: remove this line
+   | |     ------------------------------- help: remove this line
 ...  |
 LL | |     vec_deque.extend([1])
 LL | | }
    | |_^
 
 error: unnecessary call to `reserve`
-  --> tests/ui/unnecessary_reserve.rs:103:22
+  --> tests/ui/unnecessary_reserve.rs:108:22
    |
 LL |   fn box_vec_reserve() {
    |  ______________________^
 LL | |     let mut vec: Box<Vec<usize>> = Box::default();
 LL | |     let array: &[usize] = &[1, 2];
 ...  |
 LL | |     vec.reserve(array.len());
-   | |     ------------------------ help: remove this line
+   | |     ------------------------- help: remove this line
 LL | |     vec.extend(array);
 LL | | }
    | |_^