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.

try-job: x86_64-msvc

library/alloc/src/raw_vec/tests.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/core/src/mem/mod.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")]

src/etc/gdb_providers.py

@@ -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/lldb_providers.py

@@ -389,11 +389,11 @@ def get_child_at_index(self, index):
     def update(self):
         # type: () -> None
         self.length = self.valobj.GetChildMemberWithName("len").GetValueAsUnsigned()
-        self.buf = self.valobj.GetChildMemberWithName("buf")
+        self.buf = self.valobj.GetChildMemberWithName("buf").GetChildMemberWithName("inner")
 
         self.data_ptr = unwrap_unique_or_non_null(self.buf.GetChildMemberWithName("ptr"))
 
-        self.element_type = self.data_ptr.GetType().GetPointeeType()
+        self.element_type = self.valobj.GetType().GetTemplateArgumentType(0)
         self.element_type_size = self.element_type.GetByteSize()
 
     def has_children(self):
@@ -474,15 +474,15 @@ def update(self):
         # type: () -> None
         self.head = self.valobj.GetChildMemberWithName("head").GetValueAsUnsigned()
         self.size = self.valobj.GetChildMemberWithName("len").GetValueAsUnsigned()
-        self.buf = self.valobj.GetChildMemberWithName("buf")
+        self.buf = self.valobj.GetChildMemberWithName("buf").GetChildMemberWithName("inner")
         cap = self.buf.GetChildMemberWithName("cap")
         if cap.GetType().num_fields == 1:
             cap = cap.GetChildAtIndex(0)
         self.cap = cap.GetValueAsUnsigned()
 
         self.data_ptr = unwrap_unique_or_non_null(self.buf.GetChildMemberWithName("ptr"))
 
-        self.element_type = self.data_ptr.GetType().GetPointeeType()
+        self.element_type = self.valobj.GetType().GetTemplateArgumentType(0)
         self.element_type_size = self.element_type.GetByteSize()
 
     def has_children(self):

src/etc/natvis/liballoc.natvis

@@ -4,26 +4,26 @@
     <DisplayString>{{ len={len} }}</DisplayString>
     <Expand>
       <Item Name="[len]" ExcludeView="simple">len</Item>
-      <Item Name="[capacity]" ExcludeView="simple">buf.cap.__0</Item>
+      <Item Name="[capacity]" ExcludeView="simple">buf.inner.cap.__0</Item>
       <ArrayItems>
         <Size>len</Size>
-        <ValuePointer>buf.ptr.pointer.pointer</ValuePointer>
+        <ValuePointer>($T1*)buf.inner.ptr.pointer.pointer</ValuePointer>
       </ArrayItems>
     </Expand>
   </Type>
   <Type Name="alloc::collections::vec_deque::VecDeque&lt;*&gt;">
     <DisplayString>{{ len={len} }}</DisplayString>
     <Expand>
       <Item Name="[len]" ExcludeView="simple">len</Item>
-      <Item Name="[capacity]" ExcludeView="simple">buf.cap.__0</Item>
+      <Item Name="[capacity]" ExcludeView="simple">buf.inner.cap.__0</Item>
       <CustomListItems>
         <Variable Name="i" InitialValue="0" />
         <Size>len</Size>
         <Loop>
           <If Condition="i == len">
             <Break/>
           </If>
-          <Item>buf.ptr.pointer.pointer[(i + head) % buf.cap.__0]</Item>
+          <Item>(($T1*)buf.inner.ptr.pointer.pointer)[(i + head) % buf.inner.cap.__0]</Item>
           <Exec>i = i + 1</Exec>
         </Loop>
       </CustomListItems>
@@ -41,17 +41,17 @@
     </Expand>
   </Type>
   <Type Name="alloc::string::String">
-    <DisplayString>{(char*)vec.buf.ptr.pointer.pointer,[vec.len]s8}</DisplayString>
-    <StringView>(char*)vec.buf.ptr.pointer.pointer,[vec.len]s8</StringView>
+    <DisplayString>{(char*)vec.buf.inner.ptr.pointer.pointer,[vec.len]s8}</DisplayString>
+    <StringView>(char*)vec.buf.inner.ptr.pointer.pointer,[vec.len]s8</StringView>
     <Expand>
       <Item Name="[len]" ExcludeView="simple">vec.len</Item>
-      <Item Name="[capacity]" ExcludeView="simple">vec.buf.cap.__0</Item>
+      <Item Name="[capacity]" ExcludeView="simple">vec.buf.inner.cap.__0</Item>
       <Synthetic Name="[chars]">
-        <DisplayString>{(char*)vec.buf.ptr.pointer.pointer,[vec.len]s8}</DisplayString>
+        <DisplayString>{(char*)vec.buf.inner.ptr.pointer.pointer,[vec.len]s8}</DisplayString>
         <Expand>
           <ArrayItems>
             <Size>vec.len</Size>
-            <ValuePointer>(char*)vec.buf.ptr.pointer.pointer</ValuePointer>
+            <ValuePointer>(char*)vec.buf.inner.ptr.pointer.pointer</ValuePointer>
           </ArrayItems>
         </Expand>
       </Synthetic>

src/etc/natvis/libstd.natvis

@@ -104,14 +104,14 @@
   </Type>
 
   <Type Name="std::ffi::os_str::OsString">
-    <DisplayString>{(char*)inner.inner.bytes.buf.ptr.pointer.pointer,[inner.inner.bytes.len]}</DisplayString>
+    <DisplayString>{(char*)inner.inner.bytes.buf.inner.ptr.pointer.pointer,[inner.inner.bytes.len]}</DisplayString>
     <Expand>
       <Synthetic Name="[chars]">
-        <DisplayString>{(char*)inner.inner.bytes.buf.ptr.pointer.pointer,[inner.inner.bytes.len]}</DisplayString>
+        <DisplayString>{(char*)inner.inner.bytes.buf.inner.ptr.pointer.pointer,[inner.inner.bytes.len]}</DisplayString>
         <Expand>
           <ArrayItems>
             <Size>inner.inner.bytes.len</Size>
-            <ValuePointer>(char*)inner.inner.bytes.buf.ptr.pointer.pointer</ValuePointer>
+            <ValuePointer>(char*)inner.inner.bytes.buf.inner.ptr.pointer.pointer</ValuePointer>
           </ArrayItems>
         </Expand>
       </Synthetic>

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

@@ -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.stderr

@@ -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/miri/tests/pass/tree_borrows/vec_unique.rs

@@ -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.uniq.stderr

@@ -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()>
 ──────────────────────────────────────────────────

tests/debuginfo/pretty-std.rs

@@ -81,10 +81,10 @@
 // cdb-check:vec,d [...] : { len=4 } [Type: [...]::Vec<u64,alloc::alloc::Global>]
 // cdb-check:    [len]            : 4 [Type: [...]]
 // cdb-check:    [capacity]       : [...] [Type: [...]]
-// cdb-check:    [0]              : 4 [Type: unsigned __int64]
-// cdb-check:    [1]              : 5 [Type: unsigned __int64]
-// cdb-check:    [2]              : 6 [Type: unsigned __int64]
-// cdb-check:    [3]              : 7 [Type: unsigned __int64]
+// cdb-check:    [0]              : 4 [Type: u64]
+// cdb-check:    [1]              : 5 [Type: u64]
+// cdb-check:    [2]              : 6 [Type: u64]
+// cdb-check:    [3]              : 7 [Type: u64]
 
 // cdb-command: dx str_slice
 // cdb-check:str_slice        : "IAMA string slice!" [Type: ref$<str$>]
@@ -141,8 +141,8 @@
 // cdb-check:    [<Raw View>]     [Type: alloc::collections::vec_deque::VecDeque<i32,alloc::alloc::Global>]
 // cdb-check:    [len]            : 0x2 [Type: unsigned [...]]
 // cdb-check:    [capacity]       : 0x8 [Type: unsigned [...]]
-// cdb-check:    [0x0]            : 90 [Type: int]
-// cdb-check:    [0x1]            : 20 [Type: int]
+// cdb-check:    [0x0]            : 90 [Type: i32]
+// cdb-check:    [0x1]            : 20 [Type: i32]
 
 #![allow(unused_variables)]
 use std::collections::{LinkedList, VecDeque};

tests/debuginfo/strings-and-strs.rs

@@ -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"