implement collect handling

Author: lucarlig

lints/par_iter/src/lib.rs

@@ -17,16 +17,15 @@ mod variable_check;
 use clippy_utils::{get_parent_expr, get_trait_def_id};
 use rustc_data_structures::fx::FxHashSet;
 use rustc_errors::Applicability;
-use rustc_hir::intravisit::Visitor;
+use rustc_hir::intravisit::{walk_expr, Visitor};
 use rustc_hir::{self as hir};
 use rustc_lint::{LateContext, LateLintPass, LintContext};
-use rustc_middle::ty::{self, ty_kind::TyKind, Ty};
+use rustc_middle::ty::{self, Ty};
 use rustc_span::sym;
 use variable_check::{
     check_implements_par_iter, check_trait_impl, check_variables, generate_suggestion,
     is_type_valid,
 };
-
 dylint_linting::declare_late_lint! {
     /// ### What it does
     /// parallelize iterators using rayon
@@ -89,11 +88,6 @@ impl<'tcx> LateLintPass<'tcx> for ParIter {
                     return;
                 }
 
-                // TODO: this needs to change and find a better solutions for returns
-                if let TyKind::Adt(_, _) = ty.kind() {
-                    return;
-                }
-
                 let mut validator = Validator { cx, is_valid: true };
                 validator.visit_expr(top_expr);
                 if !validator.is_valid {
@@ -128,14 +122,17 @@ impl<'a, 'tcx> hir::intravisit::Visitor<'_> for Validator<'a, 'tcx> {
             if !self.is_valid {
                 return;
             }
+            let ex_ty = self.cx.typeck_results().expr_ty(ex);
+            self.is_valid &= is_type_valid(self.cx, ex_ty);
+
             for arg in args {
                 if let hir::ExprKind::Closure(closure) = arg.kind {
                     let body = self.cx.tcx.hir().body(closure.body);
-
                     self.is_valid &= check_variables(self.cx, closure.def_id, body);
                 }
             }
         }
+        walk_expr(self, ex)
     }
 }
 

lints/par_iter/ui/main.fixed

@@ -302,3 +302,50 @@ impl ApplicationState {
         self.foreground_high_qos_cases.extend(change_state_cases);
     }
 }
+
+// should parallelize
+fn collect_at_end() {
+    let people = vec![
+        Person {
+            name: "Alice".to_string(),
+            age: 25,
+        },
+        Person {
+            name: "Bob".to_string(),
+            age: 35,
+        },
+        Person {
+            name: "Carol".to_string(),
+            age: 32,
+        },
+    ];
+
+    let names: Vec<String> = people.par_iter().map(|p| p.name.clone()).collect();
+
+    println!("{:?}", names);
+}
+
+struct Tsize {
+    send: usize,
+}
+
+impl Tsize {
+    fn to_no_send(&self) -> TsizeNoSend {
+        TsizeNoSend {
+            no_send: Rc::new(self.send),
+        }
+    }
+}
+
+#[derive(Debug)]
+struct TsizeNoSend {
+    no_send: Rc<usize>,
+}
+
+// no
+fn collect_at_end_no_par() {
+    let t_size_vec: Vec<Tsize> = vec![Tsize { send: 32 }, Tsize { send: 42 }];
+    let t_size_vec_no_send: Vec<TsizeNoSend> = t_size_vec.iter().map(|t| t.to_no_send()).collect();
+
+    println!("{:?}", t_size_vec_no_send);
+}

lints/par_iter/ui/main.rs

@@ -302,3 +302,50 @@ impl ApplicationState {
         self.foreground_high_qos_cases.extend(change_state_cases);
     }
 }
+
+// should parallelize
+fn collect_at_end() {
+    let people = vec![
+        Person {
+            name: "Alice".to_string(),
+            age: 25,
+        },
+        Person {
+            name: "Bob".to_string(),
+            age: 35,
+        },
+        Person {
+            name: "Carol".to_string(),
+            age: 32,
+        },
+    ];
+
+    let names: Vec<String> = people.iter().map(|p| p.name.clone()).collect();
+
+    println!("{:?}", names);
+}
+
+struct Tsize {
+    send: usize,
+}
+
+impl Tsize {
+    fn to_no_send(&self) -> TsizeNoSend {
+        TsizeNoSend {
+            no_send: Rc::new(self.send),
+        }
+    }
+}
+
+#[derive(Debug)]
+struct TsizeNoSend {
+    no_send: Rc<usize>,
+}
+
+// no
+fn collect_at_end_no_par() {
+    let t_size_vec: Vec<Tsize> = vec![Tsize { send: 32 }, Tsize { send: 42 }];
+    let t_size_vec_no_send: Vec<TsizeNoSend> = t_size_vec.iter().map(|t| t.to_no_send()).collect();
+
+    println!("{:?}", t_size_vec_no_send);
+}

lints/par_iter/ui/main.stderr

@@ -44,5 +44,11 @@ error: found iterator that can be parallelized
 LL |     numbers.iter().enumerate().for_each(|t| {
    |     ^^^^^^^^^^^^^^ help: try using a parallel iterator: `numbers.par_iter()`
 
-error: aborting due to 6 previous errors
+error: found iterator that can be parallelized
+  --> $DIR/main.rs:323:30
+   |
+LL |     let names: Vec<String> = people.iter().map(|p| p.name.clone()).collect();
+   |                              ^^^^^^^^^^^^^ help: try using a parallel iterator: `people.par_iter()`
+
+error: aborting due to 7 previous errors
 

lints/par_iter/ui/main2.fixed

@@ -100,24 +100,3 @@ fn main() {}
 //     println!("{:?}", doubled_numbers);
 // }
 //
-// // should parallelize
-// fn collect_at_end() {
-//     let people = vec![
-//         Person {
-//             name: "Alice".to_string(),
-//             age: 25,
-//         },
-//         Person {
-//             name: "Bob".to_string(),
-//             age: 35,
-//         },
-//         Person {
-//             name: "Carol".to_string(),
-//             age: 32,
-//         },
-//     ];
-
-//     let names: Vec<String> = people.iter().map(|p| p.name.clone()).collect();
-
-//     println!("{:?}", names);
-// }

lints/par_iter/ui/main2.rs

@@ -100,24 +100,3 @@ fn main() {}
 //     println!("{:?}", doubled_numbers);
 // }
 //
-// // should parallelize
-// fn collect_at_end() {
-//     let people = vec![
-//         Person {
-//             name: "Alice".to_string(),
-//             age: 25,
-//         },
-//         Person {
-//             name: "Bob".to_string(),
-//             age: 35,
-//         },
-//         Person {
-//             name: "Carol".to_string(),
-//             age: 32,
-//         },
-//     ];
-
-//     let names: Vec<String> = people.iter().map(|p| p.name.clone()).collect();
-
-//     println!("{:?}", names);
-// }