Auto merge of rust-lang#126793 - saethlin:mono-rawvec, r=scottmcm

Apply "polymorphization at home" to RawVec

The idea here is to move all the logic in RawVec into functions with explicit size and alignment parameters. This should eliminate all the fussing about how tweaking RawVec code produces large swings in compile times.

This uncovered rust-lang/rust-clippy#12979, so I've modified the relevant test in a way that tries to preserve the spirit of the test without tripping the ICE.

Author: bors

library/alloc/src/raw_vec.rs

@@ -43,9 +43,9 @@ fn allocator_param() {
 
     let a = BoundedAlloc { fuel: Cell::new(500) };
     let mut v: RawVec<u8, _> = RawVec::with_capacity_in(50, a);
-    assert_eq!(v.alloc.fuel.get(), 450);
+    assert_eq!(v.inner.alloc.fuel.get(), 450);
     v.reserve(50, 150); // (causes a realloc, thus using 50 + 150 = 200 units of fuel)
-    assert_eq!(v.alloc.fuel.get(), 250);
+    assert_eq!(v.inner.alloc.fuel.get(), 250);
 }
 
 #[test]
@@ -86,7 +86,7 @@ struct ZST;
 fn zst_sanity<T>(v: &RawVec<T>) {
     assert_eq!(v.capacity(), usize::MAX);
     assert_eq!(v.ptr(), core::ptr::Unique::<T>::dangling().as_ptr());
-    assert_eq!(v.current_memory(), None);
+    assert_eq!(v.inner.current_memory(T::LAYOUT), None);
 }
 
 #[test]
@@ -106,22 +106,11 @@ fn zst() {
     let v: RawVec<ZST> = RawVec::with_capacity_in(100, Global);
     zst_sanity(&v);
 
-    let v: RawVec<ZST> = RawVec::try_allocate_in(0, AllocInit::Uninitialized, Global).unwrap();
-    zst_sanity(&v);
-
-    let v: RawVec<ZST> = RawVec::try_allocate_in(100, AllocInit::Uninitialized, Global).unwrap();
-    zst_sanity(&v);
-
-    let mut v: RawVec<ZST> =
-        RawVec::try_allocate_in(usize::MAX, AllocInit::Uninitialized, Global).unwrap();
+    let mut v: RawVec<ZST> = RawVec::with_capacity_in(usize::MAX, Global);
     zst_sanity(&v);
 
     // Check all these operations work as expected with zero-sized elements.
 
-    assert!(!v.needs_to_grow(100, usize::MAX - 100));
-    assert!(v.needs_to_grow(101, usize::MAX - 100));
-    zst_sanity(&v);
-
     v.reserve(100, usize::MAX - 100);
     //v.reserve(101, usize::MAX - 100); // panics, in `zst_reserve_panic` below
     zst_sanity(&v);
@@ -138,12 +127,12 @@ fn zst() {
     assert_eq!(v.try_reserve_exact(101, usize::MAX - 100), cap_err);
     zst_sanity(&v);
 
-    assert_eq!(v.grow_amortized(100, usize::MAX - 100), cap_err);
-    assert_eq!(v.grow_amortized(101, usize::MAX - 100), cap_err);
+    assert_eq!(v.inner.grow_amortized(100, usize::MAX - 100, ZST::LAYOUT), cap_err);
+    assert_eq!(v.inner.grow_amortized(101, usize::MAX - 100, ZST::LAYOUT), cap_err);
     zst_sanity(&v);
 
-    assert_eq!(v.grow_exact(100, usize::MAX - 100), cap_err);
-    assert_eq!(v.grow_exact(101, usize::MAX - 100), cap_err);
+    assert_eq!(v.inner.grow_exact(100, usize::MAX - 100, ZST::LAYOUT), cap_err);
+    assert_eq!(v.inner.grow_exact(101, usize::MAX - 100, ZST::LAYOUT), cap_err);
     zst_sanity(&v);
 }
 

library/alloc/src/raw_vec/tests.rs

@@ -5,6 +5,7 @@
 
 #![stable(feature = "rust1", since = "1.0.0")]
 
+use crate::alloc::Layout;
 use crate::marker::DiscriminantKind;
 use crate::{clone, cmp, fmt, hash, intrinsics, ptr};
 
@@ -1238,6 +1239,10 @@ pub trait SizedTypeProperties: Sized {
     #[doc(hidden)]
     #[unstable(feature = "sized_type_properties", issue = "none")]
     const IS_ZST: bool = size_of::<Self>() == 0;
+
+    #[doc(hidden)]
+    #[unstable(feature = "sized_type_properties", issue = "none")]
+    const LAYOUT: Layout = Layout::new::<Self>();
 }
 #[doc(hidden)]
 #[unstable(feature = "sized_type_properties", issue = "none")]

library/core/src/mem/mod.rs

@@ -56,7 +56,7 @@ def __init__(self, valobj):
         self._valobj = valobj
         vec = valobj["vec"]
         self._length = int(vec["len"])
-        self._data_ptr = unwrap_unique_or_non_null(vec["buf"]["ptr"])
+        self._data_ptr = unwrap_unique_or_non_null(vec["buf"]["inner"]["ptr"])
 
     def to_string(self):
         return self._data_ptr.lazy_string(encoding="utf-8", length=self._length)
@@ -74,7 +74,7 @@ def __init__(self, valobj):
         vec = buf[ZERO_FIELD] if is_windows else buf
 
         self._length = int(vec["len"])
-        self._data_ptr = unwrap_unique_or_non_null(vec["buf"]["ptr"])
+        self._data_ptr = unwrap_unique_or_non_null(vec["buf"]["inner"]["ptr"])
 
     def to_string(self):
         return self._data_ptr.lazy_string(encoding="utf-8", length=self._length)
@@ -96,6 +96,7 @@ def to_string(self):
     def display_hint():
         return "string"
 
+
 def _enumerate_array_elements(element_ptrs):
     for (i, element_ptr) in enumerate(element_ptrs):
         key = "[{}]".format(i)
@@ -112,6 +113,7 @@ def _enumerate_array_elements(element_ptrs):
 
         yield key, element
 
+
 class StdSliceProvider(printer_base):
     def __init__(self, valobj):
         self._valobj = valobj
@@ -130,11 +132,14 @@ def children(self):
     def display_hint():
         return "array"
 
+
 class StdVecProvider(printer_base):
     def __init__(self, valobj):
         self._valobj = valobj
         self._length = int(valobj["len"])
-        self._data_ptr = unwrap_unique_or_non_null(valobj["buf"]["ptr"])
+        self._data_ptr = unwrap_unique_or_non_null(valobj["buf"]["inner"]["ptr"])
+        ptr_ty = gdb.Type.pointer(valobj.type.template_argument(0))
+        self._data_ptr = self._data_ptr.reinterpret_cast(ptr_ty)
 
     def to_string(self):
         return "Vec(size={})".format(self._length)
@@ -155,11 +160,13 @@ def __init__(self, valobj):
         self._head = int(valobj["head"])
         self._size = int(valobj["len"])
         # BACKCOMPAT: rust 1.75
-        cap = valobj["buf"]["cap"]
+        cap = valobj["buf"]["inner"]["cap"]
         if cap.type.code != gdb.TYPE_CODE_INT:
             cap = cap[ZERO_FIELD]
         self._cap = int(cap)
-        self._data_ptr = unwrap_unique_or_non_null(valobj["buf"]["ptr"])
+        self._data_ptr = unwrap_unique_or_non_null(valobj["buf"]["inner"]["ptr"])
+        ptr_ty = gdb.Type.pointer(valobj.type.template_argument(0))
+        self._data_ptr = self._data_ptr.reinterpret_cast(ptr_ty)
 
     def to_string(self):
         return "VecDeque(size={})".format(self._size)

src/etc/gdb_providers.py

@@ -10,7 +10,7 @@ use std::sync::Once;
 
 const ATOMIC: AtomicUsize = AtomicUsize::new(5);
 const CELL: Cell<usize> = Cell::new(6);
-const ATOMIC_TUPLE: ([AtomicUsize; 1], Vec<AtomicUsize>, u8) = ([ATOMIC], Vec::new(), 7);
+const ATOMIC_TUPLE: ([AtomicUsize; 1], Option<Box<AtomicUsize>>, u8) = ([ATOMIC], None, 7);
 const INTEGER: u8 = 8;
 const STRING: String = String::new();
 const STR: &str = "012345";
@@ -74,7 +74,6 @@ fn main() {
     let _ = &(&&&&ATOMIC_TUPLE).0; //~ ERROR: interior mutability
     let _ = &ATOMIC_TUPLE.0[0]; //~ ERROR: interior mutability
     let _ = ATOMIC_TUPLE.0[0].load(Ordering::SeqCst); //~ ERROR: interior mutability
-    let _ = &*ATOMIC_TUPLE.1;
     let _ = &ATOMIC_TUPLE.2;
     let _ = (&&&&ATOMIC_TUPLE).0;
     let _ = (&&&&ATOMIC_TUPLE).2;

src/tools/clippy/tests/ui/borrow_interior_mutable_const/others.rs

@@ -92,23 +92,23 @@ LL |     let _ = ATOMIC_TUPLE.0[0].load(Ordering::SeqCst);
    = help: assign this const to a local or static variable, and use the variable here
 
 error: a `const` item with interior mutability should not be borrowed
-  --> tests/ui/borrow_interior_mutable_const/others.rs:82:13
+  --> tests/ui/borrow_interior_mutable_const/others.rs:81:13
    |
 LL |     let _ = ATOMIC_TUPLE.0[0];
    |             ^^^^^^^^^^^^
    |
    = help: assign this const to a local or static variable, and use the variable here
 
 error: a `const` item with interior mutability should not be borrowed
-  --> tests/ui/borrow_interior_mutable_const/others.rs:87:5
+  --> tests/ui/borrow_interior_mutable_const/others.rs:86:5
    |
 LL |     CELL.set(2);
    |     ^^^^
    |
    = help: assign this const to a local or static variable, and use the variable here
 
 error: a `const` item with interior mutability should not be borrowed
-  --> tests/ui/borrow_interior_mutable_const/others.rs:88:16
+  --> tests/ui/borrow_interior_mutable_const/others.rs:87:16
    |
 LL |     assert_eq!(CELL.get(), 6);
    |                ^^^^

src/tools/clippy/tests/ui/borrow_interior_mutable_const/others.stderr

@@ -1,3 +1,5 @@
+// FIXME: This test is broken since https://github.com/rust-lang/rust/pull/126793,
+// possibly related to the additional struct between Vec and Unique.
 //@revisions: default uniq
 // We disable the GC for this test because it would change what is printed.
 //@compile-flags: -Zmiri-tree-borrows -Zmiri-provenance-gc=0

src/tools/miri/tests/pass/tree_borrows/vec_unique.rs

@@ -2,7 +2,9 @@
 Warning: this tree is indicative only. Some tags may have been hidden.
 0..   2
 | Act |    └─┬──<TAG=root of the allocation>
-|-----|      └─┬──<TAG=base.as_ptr(), base.as_ptr()>
-|-----|        └─┬──<TAG=raw_parts.0>
-|-----|          └────<TAG=reconstructed.as_ptr(), reconstructed.as_ptr()>
+|-----|      ├────<TAG=base.as_ptr()>
+|-----|      ├────<TAG=base.as_ptr()>
+|-----|      └─┬──<TAG=raw_parts.0>
+|-----|        ├────<TAG=reconstructed.as_ptr()>
+|-----|        └────<TAG=reconstructed.as_ptr()>
 ──────────────────────────────────────────────────

src/tools/miri/tests/pass/tree_borrows/vec_unique.uniq.stderr

@@ -7,7 +7,7 @@
 // gdb-command:run
 
 // gdb-command:print plain_string
-// gdbr-check:$1 = alloc::string::String {vec: alloc::vec::Vec<u8, alloc::alloc::Global> {buf: alloc::raw_vec::RawVec<u8, alloc::alloc::Global> {ptr: core::ptr::unique::Unique<u8> {pointer: core::ptr::non_null::NonNull<u8> {pointer: 0x[...]}, _marker: core::marker::PhantomData<u8>}, cap: alloc::raw_vec::Cap (5), alloc: alloc::alloc::Global}, len: 5}}
+// gdbr-check:$1 = alloc::string::String {vec: alloc::vec::Vec<u8, alloc::alloc::Global> {buf: alloc::raw_vec::RawVec<u8, alloc::alloc::Global> {inner: alloc::raw_vec::RawVecInner<alloc::alloc::Global> {ptr: core::ptr::unique::Unique<u8> {pointer: core::ptr::non_null::NonNull<u8> {pointer: 0x[...]}, _marker: core::marker::PhantomData<u8>}, cap: alloc::raw_vec::Cap (5), alloc: alloc::alloc::Global}, _marker: core::marker::PhantomData<u8>}, len: 5}}
 
 // gdb-command:print plain_str
 // gdbr-check:$2 = "Hello"

tests/debuginfo/strings-and-strs.rs

@@ -5,63 +5,93 @@ fn vec_deref_to_slice(_1: &Vec<u8>) -> &[u8] {
     let mut _0: &[u8];
     scope 1 (inlined <Vec<u8> as Deref>::deref) {
         debug self => _1;
-        let mut _4: *const u8;
-        let mut _5: usize;
+        let mut _7: usize;
         scope 2 (inlined Vec::<u8>::as_ptr) {
             debug self => _1;
             let mut _2: &alloc::raw_vec::RawVec<u8>;
             scope 3 (inlined alloc::raw_vec::RawVec::<u8>::ptr) {
                 debug self => _2;
-                let mut _3: std::ptr::NonNull<u8>;
-                scope 4 (inlined Unique::<u8>::as_ptr) {
-                    debug ((self: Unique<u8>).0: std::ptr::NonNull<u8>) => _3;
-                    debug ((self: Unique<u8>).1: std::marker::PhantomData<u8>) => const PhantomData::<u8>;
-                    scope 5 (inlined NonNull::<u8>::as_ptr) {
+                let mut _3: &alloc::raw_vec::RawVecInner;
+                scope 4 (inlined alloc::raw_vec::RawVecInner::ptr::<u8>) {
+                    debug self => _3;
+                    let mut _6: std::ptr::NonNull<u8>;
+                    scope 5 (inlined alloc::raw_vec::RawVecInner::non_null::<u8>) {
                         debug self => _3;
+                        let mut _4: std::ptr::NonNull<u8>;
+                        scope 6 (inlined Unique::<u8>::cast::<u8>) {
+                            debug ((self: Unique<u8>).0: std::ptr::NonNull<u8>) => _4;
+                            debug ((self: Unique<u8>).1: std::marker::PhantomData<u8>) => const PhantomData::<u8>;
+                            scope 7 (inlined NonNull::<u8>::cast::<u8>) {
+                                debug self => _4;
+                                scope 8 (inlined NonNull::<u8>::as_ptr) {
+                                    debug self => _4;
+                                    let mut _5: *const u8;
+                                }
+                            }
+                        }
+                        scope 9 (inlined #[track_caller] <Unique<u8> as Into<NonNull<u8>>>::into) {
+                            debug ((self: Unique<u8>).0: std::ptr::NonNull<u8>) => _6;
+                            debug ((self: Unique<u8>).1: std::marker::PhantomData<u8>) => const PhantomData::<u8>;
+                            scope 10 (inlined <NonNull<u8> as From<Unique<u8>>>::from) {
+                                debug ((unique: Unique<u8>).0: std::ptr::NonNull<u8>) => _6;
+                                debug ((unique: Unique<u8>).1: std::marker::PhantomData<u8>) => const PhantomData::<u8>;
+                                scope 11 (inlined Unique::<u8>::as_non_null_ptr) {
+                                    debug ((self: Unique<u8>).0: std::ptr::NonNull<u8>) => _6;
+                                    debug ((self: Unique<u8>).1: std::marker::PhantomData<u8>) => const PhantomData::<u8>;
+                                }
+                            }
+                        }
+                    }
+                    scope 12 (inlined NonNull::<u8>::as_ptr) {
+                        debug self => _6;
                     }
                 }
             }
         }
-        scope 6 (inlined std::slice::from_raw_parts::<'_, u8>) {
-            debug data => _4;
-            debug len => _5;
-            let _6: *const [u8];
-            scope 7 (inlined core::ub_checks::check_language_ub) {
-                scope 8 (inlined core::ub_checks::check_language_ub::runtime) {
+        scope 13 (inlined std::slice::from_raw_parts::<'_, u8>) {
+            debug data => _5;
+            debug len => _7;
+            let _8: *const [u8];
+            scope 14 (inlined core::ub_checks::check_language_ub) {
+                scope 15 (inlined core::ub_checks::check_language_ub::runtime) {
                 }
             }
-            scope 9 (inlined std::mem::size_of::<u8>) {
+            scope 16 (inlined std::mem::size_of::<u8>) {
             }
-            scope 10 (inlined align_of::<u8>) {
+            scope 17 (inlined align_of::<u8>) {
             }
-            scope 11 (inlined slice_from_raw_parts::<u8>) {
-                debug data => _4;
-                debug len => _5;
-                scope 12 (inlined std::ptr::from_raw_parts::<[u8], u8>) {
-                    debug data_pointer => _4;
-                    debug metadata => _5;
+            scope 18 (inlined slice_from_raw_parts::<u8>) {
+                debug data => _5;
+                debug len => _7;
+                scope 19 (inlined std::ptr::from_raw_parts::<[u8], u8>) {
+                    debug data_pointer => _5;
+                    debug metadata => _7;
                 }
             }
         }
     }
 
     bb0: {
-        StorageLive(_4);
         StorageLive(_2);
         _2 = &((*_1).0: alloc::raw_vec::RawVec<u8>);
         StorageLive(_3);
-        _3 = ((((*_1).0: alloc::raw_vec::RawVec<u8>).0: std::ptr::Unique<u8>).0: std::ptr::NonNull<u8>);
-        _4 = (_3.0: *const u8);
-        StorageDead(_3);
-        StorageDead(_2);
-        StorageLive(_5);
-        _5 = ((*_1).1: usize);
+        _3 = &(((*_1).0: alloc::raw_vec::RawVec<u8>).0: alloc::raw_vec::RawVecInner);
         StorageLive(_6);
-        _6 = *const [u8] from (_4, _5);
-        _0 = &(*_6);
-        StorageDead(_6);
-        StorageDead(_5);
+        StorageLive(_4);
+        _4 = (((((*_1).0: alloc::raw_vec::RawVec<u8>).0: alloc::raw_vec::RawVecInner).0: std::ptr::Unique<u8>).0: std::ptr::NonNull<u8>);
+        _5 = (_4.0: *const u8);
+        _6 = NonNull::<u8> { pointer: _5 };
         StorageDead(_4);
+        StorageDead(_6);
+        StorageDead(_3);
+        StorageDead(_2);
+        StorageLive(_7);
+        _7 = ((*_1).1: usize);
+        StorageLive(_8);
+        _8 = *const [u8] from (_5, _7);
+        _0 = &(*_8);
+        StorageDead(_8);
+        StorageDead(_7);
         return;
     }
 }