Do not lint inside macros

Author: agroudiev

clippy_lints/src/reserve_after_initialization.rs

@@ -1,7 +1,7 @@
 use clippy_utils::diagnostics::span_lint_and_sugg;
 use clippy_utils::higher::{get_vec_init_kind, VecInitKind};
-use clippy_utils::path_to_local_id;
 use clippy_utils::source::snippet;
+use clippy_utils::{is_from_proc_macro, path_to_local_id};
 use rustc_errors::Applicability;
 use rustc_hir::def::Res;
 use rustc_hir::{BindingAnnotation, Block, Expr, ExprKind, HirId, Local, PatKind, QPath, Stmt, StmtKind};
@@ -74,8 +74,9 @@ impl<'tcx> LateLintPass<'tcx> for ReserveAfterInitialization {
             && let PatKind::Binding(BindingAnnotation::MUT, id, _, None) = local.pat.kind
             && !in_external_macro(cx.sess(), local.span)
             && let Some(init) = get_vec_init_kind(cx, init_expr)
-            && !matches!(init, VecInitKind::WithExprCapacity(_))
-            && !matches!(init, VecInitKind::WithConstCapacity(_))
+            && !matches!(init, VecInitKind::WithExprCapacity(_)
+               | VecInitKind::WithConstCapacity(_)
+            )
         {
             self.searcher = Some(VecReserveSearcher {
                 local_id: id,
@@ -116,6 +117,7 @@ impl<'tcx> LateLintPass<'tcx> for ReserveAfterInitialization {
             if let StmtKind::Expr(expr) | StmtKind::Semi(expr) = stmt.kind
                 && let ExprKind::MethodCall(name, self_arg, [space_hint], _) = expr.kind
                 && path_to_local_id(self_arg, searcher.local_id)
+                && !is_from_proc_macro(cx, expr)
                 && name.ident.as_str() == "reserve"
             {
                 self.searcher = Some(VecReserveSearcher {

tests/ui/reserve_after_initialization.fixed

@@ -1,6 +1,10 @@
+//@aux-build:proc_macros.rs
 #![warn(clippy::reserve_after_initialization)]
 #![no_main]
 
+extern crate proc_macros;
+use proc_macros::{external, with_span};
+
 // Should lint
 fn standard() {
     let mut v1: Vec<usize> = Vec::with_capacity(10);
@@ -29,28 +33,16 @@ fn assign_expression() {
     v5 = Vec::with_capacity(10);
 }
 
-/*fn in_macros() {
+fn in_macros() {
     external! {
-        // Should lint
-        let mut v1: Vec<usize> = vec![];
-        v1.reserve(10);
-
-        // Should lint
-        let capacity = 10;
-        let mut v2: Vec<usize> = vec![];
-        v2.reserve(capacity);
+        let mut v: Vec<usize> = vec![];
+        v.reserve(10);
     }
 
     with_span! {
         span
 
-        // Should lint
-        let mut v1: Vec<usize> = vec![];
-        v1.reserve(10);
-
-        // Should lint
-        let capacity = 10;
-        let mut v2: Vec<usize> = vec![];
-        v2.reserve(capacity);
+        let mut v: Vec<usize> = vec![];
+        v.reserve(10);
     }
-}*/
+}

tests/ui/reserve_after_initialization.rs

@@ -1,6 +1,10 @@
+//@aux-build:proc_macros.rs
 #![warn(clippy::reserve_after_initialization)]
 #![no_main]
 
+extern crate proc_macros;
+use proc_macros::{external, with_span};
+
 // Should lint
 fn standard() {
     let mut v1: Vec<usize> = vec![];
@@ -32,28 +36,16 @@ fn assign_expression() {
     v5.reserve(10);
 }
 
-/*fn in_macros() {
+fn in_macros() {
     external! {
-        // Should lint
-        let mut v1: Vec<usize> = vec![];
-        v1.reserve(10);
-
-        // Should lint
-        let capacity = 10;
-        let mut v2: Vec<usize> = vec![];
-        v2.reserve(capacity);
+        let mut v: Vec<usize> = vec![];
+        v.reserve(10);
     }
 
     with_span! {
         span
 
-        // Should lint
-        let mut v1: Vec<usize> = vec![];
-        v1.reserve(10);
-
-        // Should lint
-        let capacity = 10;
-        let mut v2: Vec<usize> = vec![];
-        v2.reserve(capacity);
+        let mut v: Vec<usize> = vec![];
+        v.reserve(10);
     }
-}*/
+}

tests/ui/reserve_after_initialization.stderr

@@ -1,5 +1,5 @@
 error: call to `reserve` immediately after creation
-  --> $DIR/reserve_after_initialization.rs:6:5
+  --> $DIR/reserve_after_initialization.rs:10:5
    |
 LL | /     let mut v1: Vec<usize> = vec![];
 LL | |     v1.reserve(10);
@@ -8,14 +8,14 @@ LL | |     v1.reserve(10);
    = note: `-D clippy::reserve-after-initialization` implied by `-D warnings`
 
 error: call to `reserve` immediately after creation
-  --> $DIR/reserve_after_initialization.rs:13:5
+  --> $DIR/reserve_after_initialization.rs:17:5
    |
 LL | /     let mut v2: Vec<usize> = vec![];
 LL | |     v2.reserve(capacity);
    | |_________________________^ help: consider using `Vec::with_capacity(/* Space hint */)`: `let mut v2: Vec<usize> = Vec::with_capacity(capacity);`
 
 error: call to `reserve` immediately after creation
-  --> $DIR/reserve_after_initialization.rs:31:5
+  --> $DIR/reserve_after_initialization.rs:35:5
    |
 LL | /     v5 = Vec::new();
 LL | |     v5.reserve(10);