add support for std::alloc::Global, add more tests

tests/ui/vec_box_sized.fixed

@@ -1,13 +1,26 @@
 #![allow(dead_code)]
 #![feature(allocator_api)]
 
+use std::alloc::{Layout, AllocError, Allocator};
+use std::ptr::NonNull;
+
 struct SizedStruct(i32);
 struct UnsizedStruct([i32]);
 struct BigStruct([i32; 10000]);
 
+struct DummyAllocator;
+unsafe impl Allocator for DummyAllocator {
+    fn allocate(&self, layout: Layout) -> Result<NonNull<[u8]>, AllocError> {
+        todo!()
+    }
+    unsafe fn deallocate(&self, ptr: NonNull<u8>, layout: Layout) {
+        todo!()
+    }
+}
+
 /// The following should trigger the lint
 mod should_trigger {
-    use super::SizedStruct;
+    use super::{SizedStruct, DummyAllocator};
     const C: Vec<i32> = Vec::new();
     static S: Vec<i32> = Vec::new();
 
@@ -17,13 +30,21 @@ mod should_trigger {
 
     struct A(Vec<SizedStruct>);
     struct B(Vec<Vec<u32>>);
+
+    fn allocator_global_defined_vec() -> Vec<i32> {
+        Vec::new()
+    }
+    fn allocator_global_defined_box() -> Vec<i32> {
+        Vec::new()
+    }
+    fn allocator_match() -> Vec<i32> {
+        Vec::new_in(DummyAllocator)
+    }
 }
 
 /// The following should not trigger the lint
 mod should_not_trigger {
-    use super::{BigStruct, UnsizedStruct};
-    use std::alloc::{Layout, AllocError, Allocator};
-    use std::ptr::NonNull;
+    use super::{BigStruct, UnsizedStruct, DummyAllocator};
 
     struct C(Vec<Box<UnsizedStruct>>);
     struct D(Vec<Box<BigStruct>>);
@@ -37,18 +58,8 @@ mod should_not_trigger {
         inner: Vec<Box<T>>,
     }
 
-    struct DummyAllocator;
-    unsafe impl Allocator for DummyAllocator {
-        fn allocate(&self, layout: Layout) -> Result<NonNull<[u8]>, AllocError> {
-            todo!()
-        }
-        unsafe fn deallocate(&self, ptr: NonNull<u8>, layout: Layout) {
-            todo!()
-        }
-    }
-
     fn allocator_mismatch() -> Vec<Box<i32, DummyAllocator>> {
-        vec![]
+        Vec::new()
     }
 }
 

tests/ui/vec_box_sized.rs

@@ -1,13 +1,26 @@
 #![allow(dead_code)]
 #![feature(allocator_api)]
 
+use std::alloc::{Layout, AllocError, Allocator};
+use std::ptr::NonNull;
+
 struct SizedStruct(i32);
 struct UnsizedStruct([i32]);
 struct BigStruct([i32; 10000]);
 
+struct DummyAllocator;
+unsafe impl Allocator for DummyAllocator {
+    fn allocate(&self, layout: Layout) -> Result<NonNull<[u8]>, AllocError> {
+        todo!()
+    }
+    unsafe fn deallocate(&self, ptr: NonNull<u8>, layout: Layout) {
+        todo!()
+    }
+}
+
 /// The following should trigger the lint
 mod should_trigger {
-    use super::SizedStruct;
+    use super::{SizedStruct, DummyAllocator};
     const C: Vec<Box<i32>> = Vec::new();
     static S: Vec<Box<i32>> = Vec::new();
 
@@ -17,13 +30,21 @@ mod should_trigger {
 
     struct A(Vec<Box<SizedStruct>>);
     struct B(Vec<Vec<Box<(u32)>>>);
+
+    fn allocator_global_defined_vec() -> Vec<Box<i32>, std::alloc::Global> {
+        Vec::new()
+    }
+    fn allocator_global_defined_box() -> Vec<Box<i32, std::alloc::Global>> {
+        Vec::new()
+    }
+    fn allocator_match() -> Vec<Box<i32, DummyAllocator>, DummyAllocator> {
+        Vec::new_in(DummyAllocator)
+    }
 }
 
 /// The following should not trigger the lint
 mod should_not_trigger {
-    use super::{BigStruct, UnsizedStruct};
-    use std::alloc::{Layout, AllocError, Allocator};
-    use std::ptr::NonNull;
+    use super::{BigStruct, UnsizedStruct, DummyAllocator};
 
     struct C(Vec<Box<UnsizedStruct>>);
     struct D(Vec<Box<BigStruct>>);
@@ -37,18 +58,8 @@ mod should_not_trigger {
         inner: Vec<Box<T>>,
     }
 
-    struct DummyAllocator;
-    unsafe impl Allocator for DummyAllocator {
-        fn allocate(&self, layout: Layout) -> Result<NonNull<[u8]>, AllocError> {
-            todo!()
-        }
-        unsafe fn deallocate(&self, ptr: NonNull<u8>, layout: Layout) {
-            todo!()
-        }
-    }
-
     fn allocator_mismatch() -> Vec<Box<i32, DummyAllocator>> {
-        vec![]
+        Vec::new()
     }
 }
 

tests/ui/vec_box_sized.stderr

@@ -1,5 +1,5 @@
 error: `Vec<T>` is already on the heap, the boxing is unnecessary
-  --> $DIR/vec_box_sized.rs:11:14
+  --> $DIR/vec_box_sized.rs:24:14
    |
 LL |     const C: Vec<Box<i32>> = Vec::new();
    |              ^^^^^^^^^^^^^ help: try: `Vec<i32>`
@@ -8,34 +8,52 @@ LL |     const C: Vec<Box<i32>> = Vec::new();
    = help: to override `-D warnings` add `#[allow(clippy::vec_box)]`
 
 error: `Vec<T>` is already on the heap, the boxing is unnecessary
-  --> $DIR/vec_box_sized.rs:12:15
+  --> $DIR/vec_box_sized.rs:25:15
    |
 LL |     static S: Vec<Box<i32>> = Vec::new();
    |               ^^^^^^^^^^^^^ help: try: `Vec<i32>`
 
 error: `Vec<T>` is already on the heap, the boxing is unnecessary
-  --> $DIR/vec_box_sized.rs:15:21
+  --> $DIR/vec_box_sized.rs:28:21
    |
 LL |         sized_type: Vec<Box<SizedStruct>>,
    |                     ^^^^^^^^^^^^^^^^^^^^^ help: try: `Vec<SizedStruct>`
 
 error: `Vec<T>` is already on the heap, the boxing is unnecessary
-  --> $DIR/vec_box_sized.rs:18:14
+  --> $DIR/vec_box_sized.rs:31:14
    |
 LL |     struct A(Vec<Box<SizedStruct>>);
    |              ^^^^^^^^^^^^^^^^^^^^^ help: try: `Vec<SizedStruct>`
 
 error: `Vec<T>` is already on the heap, the boxing is unnecessary
-  --> $DIR/vec_box_sized.rs:19:18
+  --> $DIR/vec_box_sized.rs:32:18
    |
 LL |     struct B(Vec<Vec<Box<(u32)>>>);
    |                  ^^^^^^^^^^^^^^^ help: try: `Vec<u32>`
 
 error: `Vec<T>` is already on the heap, the boxing is unnecessary
-  --> $DIR/vec_box_sized.rs:63:23
+  --> $DIR/vec_box_sized.rs:34:42
+   |
+LL |     fn allocator_global_defined_vec() -> Vec<Box<i32>, std::alloc::Global> {
+   |                                          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `Vec<i32>`
+
+error: `Vec<T>` is already on the heap, the boxing is unnecessary
+  --> $DIR/vec_box_sized.rs:37:42
+   |
+LL |     fn allocator_global_defined_box() -> Vec<Box<i32, std::alloc::Global>> {
+   |                                          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `Vec<i32>`
+
+error: `Vec<T>` is already on the heap, the boxing is unnecessary
+  --> $DIR/vec_box_sized.rs:40:29
+   |
+LL |     fn allocator_match() -> Vec<Box<i32, DummyAllocator>, DummyAllocator> {
+   |                             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `Vec<i32>`
+
+error: `Vec<T>` is already on the heap, the boxing is unnecessary
+  --> $DIR/vec_box_sized.rs:74:23
    |
 LL |         pub fn f() -> Vec<Box<S>> {
    |                       ^^^^^^^^^^^ help: try: `Vec<S>`
 
-error: aborting due to 6 previous errors
+error: aborting due to 9 previous errors