Global alloc; GlobalCoAllocMeta; type size tests

peter-lyons-kehl · peter-lyons-kehl · commit f26c539f73e8 · 2022-12-15T16:22:31.000-08:00
diff --git a/compiler/rustc_ast/src/ast.rs b/compiler/rustc_ast/src/ast.rs
@@ -25,6 +25,7 @@ pub use UnsafeSource::*;
 use crate::ptr::P;
 use crate::token::{self, CommentKind, Delimiter};
 use crate::tokenstream::{DelimSpan, LazyAttrTokenStream, TokenStream};
+use core::alloc::GlobalCoAllocMeta;
 use rustc_data_structures::stable_hasher::{HashStable, StableHasher};
 use rustc_data_structures::stack::ensure_sufficient_stack;
 use rustc_data_structures::sync::Lrc;
@@ -36,7 +37,6 @@ use rustc_span::{Span, DUMMY_SP};
 use std::fmt;
 use std::mem;
 use thin_vec::{thin_vec, ThinVec};
-
 /// A "Label" is an identifier of some point in sources,
 /// e.g. in the following code:
 ///
@@ -3084,26 +3084,26 @@ mod size_asserts {
     static_assert_size!(AssocItem, 104);
     static_assert_size!(AssocItemKind, 32);
     static_assert_size!(Attribute, 32);
-    static_assert_size!(Block, 48);
-    static_assert_size!(Expr, 72);
-    static_assert_size!(ExprKind, 40);
-    static_assert_size!(Fn, 184);
+    static_assert_size!(Block, 48 + mem::size_of::<GlobalCoAllocMeta>());
+    static_assert_size!(Expr, 72 + mem::size_of::<GlobalCoAllocMeta>());
+    static_assert_size!(ExprKind, 40 + mem::size_of::<GlobalCoAllocMeta>());
+    static_assert_size!(Fn, 184 + 2 * mem::size_of::<GlobalCoAllocMeta>());
     static_assert_size!(ForeignItem, 96);
     static_assert_size!(ForeignItemKind, 24);
     static_assert_size!(GenericArg, 24);
-    static_assert_size!(GenericBound, 72);
-    static_assert_size!(Generics, 72);
-    static_assert_size!(Impl, 184);
-    static_assert_size!(Item, 184);
-    static_assert_size!(ItemKind, 112);
+    static_assert_size!(GenericBound, 72 + mem::size_of::<GlobalCoAllocMeta>());
+    static_assert_size!(Generics, 72 + 2 * mem::size_of::<GlobalCoAllocMeta>());
+    static_assert_size!(Impl, 184 + 3 * mem::size_of::<GlobalCoAllocMeta>());
+    static_assert_size!(Item, 184 + 3 * mem::size_of::<GlobalCoAllocMeta>());
+    static_assert_size!(ItemKind, 112 + 3 * mem::size_of::<GlobalCoAllocMeta>());
     static_assert_size!(LitKind, 24);
     static_assert_size!(Local, 72);
     static_assert_size!(MetaItemLit, 40);
     static_assert_size!(Param, 40);
-    static_assert_size!(Pat, 88);
+    static_assert_size!(Pat, 88 + mem::size_of::<GlobalCoAllocMeta>());
     static_assert_size!(Path, 24);
     static_assert_size!(PathSegment, 24);
-    static_assert_size!(PatKind, 64);
+    static_assert_size!(PatKind, 64 + mem::size_of::<GlobalCoAllocMeta>());
     static_assert_size!(Stmt, 32);
     static_assert_size!(StmtKind, 16);
     static_assert_size!(Ty, 64);
diff --git a/compiler/rustc_ast/src/lib.rs b/compiler/rustc_ast/src/lib.rs
@@ -12,6 +12,7 @@
 #![feature(box_patterns)]
 #![feature(const_default_impls)]
 #![feature(const_trait_impl)]
+#![feature(global_co_alloc_meta)]
 #![feature(if_let_guard)]
 #![feature(let_chains)]
 #![feature(min_specialization)]
diff --git a/compiler/rustc_middle/src/lib.rs b/compiler/rustc_middle/src/lib.rs
@@ -32,6 +32,7 @@
 #![feature(exhaustive_patterns)]
 #![feature(generators)]
 #![feature(get_mut_unchecked)]
+#![feature(global_co_alloc_meta)]
 #![feature(if_let_guard)]
 #![feature(iter_from_generator)]
 #![feature(negative_impls)]
diff --git a/compiler/rustc_middle/src/mir/mod.rs b/compiler/rustc_middle/src/mir/mod.rs
@@ -2,6 +2,7 @@
 //!
 //! [rustc dev guide]: https://rustc-dev-guide.rust-lang.org/mir/index.html
 
+use core::alloc::GlobalCoAllocMeta;
 use crate::mir::interpret::{
     AllocRange, ConstAllocation, ConstValue, ErrorHandled, GlobalAlloc, LitToConstInput, Scalar,
 };
@@ -3062,7 +3063,7 @@ mod size_asserts {
     use super::*;
     use rustc_data_structures::static_assert_size;
     // tidy-alphabetical-start
-    static_assert_size!(BasicBlockData<'_>, 144);
+    static_assert_size!(BasicBlockData<'_>, 144 + mem::size_of::<GlobalCoAllocMeta>());
     static_assert_size!(LocalDecl<'_>, 56);
     static_assert_size!(Statement<'_>, 32);
     static_assert_size!(StatementKind<'_>, 16);
diff --git a/compiler/rustc_middle/src/mir/syntax.rs b/compiler/rustc_middle/src/mir/syntax.rs
@@ -3,6 +3,8 @@
 //! This is in a dedicated file so that changes to this file can be reviewed more carefully.
 //! The intention is that this file only contains datatype declarations, no code.
 
+use core::alloc::GlobalCoAllocMeta;
+use core::mem;
 use super::{BasicBlock, Constant, Field, Local, SwitchTargets, UserTypeProjection};
 
 use crate::mir::coverage::{CodeRegion, CoverageKind};
@@ -1267,6 +1269,6 @@ mod size_asserts {
     static_assert_size!(Operand<'_>, 24);
     static_assert_size!(Place<'_>, 16);
     static_assert_size!(PlaceElem<'_>, 24);
-    static_assert_size!(Rvalue<'_>, 40);
+    static_assert_size!(Rvalue<'_>, 40 + mem::size_of::<GlobalCoAllocMeta>());
     // tidy-alphabetical-end
 }
diff --git a/compiler/rustc_parse/src/lib.rs b/compiler/rustc_parse/src/lib.rs
@@ -2,6 +2,7 @@
 
 #![feature(array_windows)]
 #![feature(box_patterns)]
+#![feature(global_co_alloc_meta)]
 #![feature(if_let_guard)]
 #![feature(iter_intersperse)]
 #![feature(let_chains)]
diff --git a/compiler/rustc_parse/src/parser/attr_wrapper.rs b/compiler/rustc_parse/src/parser/attr_wrapper.rs
@@ -1,3 +1,5 @@
+use core::alloc::GlobalCoAllocMeta;
+use core::mem;
 use super::{Capturing, FlatToken, ForceCollect, Parser, ReplaceRange, TokenCursor, TrailingToken};
 use rustc_ast::token::{self, Delimiter, Token, TokenKind};
 use rustc_ast::tokenstream::{AttrTokenStream, AttributesData, ToAttrTokenStream};
@@ -469,6 +471,6 @@ mod size_asserts {
     use rustc_data_structures::static_assert_size;
     // tidy-alphabetical-start
     static_assert_size!(AttrWrapper, 16);
-    static_assert_size!(LazyAttrTokenStreamImpl, 144);
+    static_assert_size!(LazyAttrTokenStreamImpl, 144 + mem::size_of::<GlobalCoAllocMeta>());
     // tidy-alphabetical-end
 }
diff --git a/compiler/rustc_parse/src/parser/mod.rs b/compiler/rustc_parse/src/parser/mod.rs
@@ -11,6 +11,7 @@ mod stmt;
 mod ty;
 
 use crate::lexer::UnmatchedBrace;
+use core::alloc::GlobalCoAllocMeta;
 pub use attr_wrapper::AttrWrapper;
 pub use diagnostics::AttemptLocalParseRecovery;
 pub(crate) use item::FnParseMode;
@@ -168,7 +169,7 @@ pub struct Parser<'a> {
 // This type is used a lot, e.g. it's cloned when matching many declarative macro rules with nonterminals. Make sure
 // it doesn't unintentionally get bigger.
 #[cfg(all(target_arch = "x86_64", target_pointer_width = "64"))]
-rustc_data_structures::static_assert_size!(Parser<'_>, 336);
+rustc_data_structures::static_assert_size!(Parser<'_>, 336 + 4 * mem::size_of::<GlobalCoAllocMeta>());
 
 /// Stores span information about a closure.
 #[derive(Clone)]
diff --git a/compiler/rustc_trait_selection/src/lib.rs b/compiler/rustc_trait_selection/src/lib.rs
@@ -15,6 +15,7 @@
 #![feature(box_patterns)]
 #![feature(control_flow_enum)]
 #![feature(drain_filter)]
+#![feature(global_co_alloc_meta)]
 #![feature(hash_drain_filter)]
 #![feature(let_chains)]
 #![feature(if_let_guard)]
diff --git a/compiler/rustc_trait_selection/src/traits/fulfill.rs b/compiler/rustc_trait_selection/src/traits/fulfill.rs
@@ -1,4 +1,6 @@
 use crate::infer::{InferCtxt, TyOrConstInferVar};
+use core::alloc::GlobalCoAllocMeta;
+use core::mem;
 use rustc_data_structures::fx::FxHashMap;
 use rustc_data_structures::obligation_forest::ProcessResult;
 use rustc_data_structures::obligation_forest::{Error, ForestObligation, Outcome};
@@ -80,7 +82,7 @@ pub struct PendingPredicateObligation<'tcx> {
 
 // `PendingPredicateObligation` is used a lot. Make sure it doesn't unintentionally get bigger.
 #[cfg(all(target_arch = "x86_64", target_pointer_width = "64"))]
-static_assert_size!(PendingPredicateObligation<'_>, 72);
+static_assert_size!(PendingPredicateObligation<'_>, 72 + mem::size_of::<GlobalCoAllocMeta>());
 
 impl<'a, 'tcx> FulfillmentContext<'tcx> {
     /// Creates a new fulfillment context.
diff --git a/library/alloc/src/lib.rs b/library/alloc/src/lib.rs
@@ -121,6 +121,7 @@
 #![feature(extend_one)]
 #![feature(fmt_internals)]
 #![feature(fn_traits)]
+#![feature(global_co_alloc_meta)]
 #![feature(hasher_prefixfree_extras)]
 #![feature(inplace_iteration)]
 #![feature(iter_advance_by)]
@@ -174,6 +175,7 @@
 #![feature(exclusive_range_pattern)]
 #![feature(fundamental)]
 #![cfg_attr(not(test), feature(generator_trait))]
+#![feature(global_co_alloc)]
 #![feature(hashmap_internals)]
 #![feature(lang_items)]
 #![feature(min_specialization)]
diff --git a/library/alloc/src/raw_vec.rs b/library/alloc/src/raw_vec.rs
@@ -1,6 +1,6 @@
 #![unstable(feature = "raw_vec_internals", reason = "unstable const warnings", issue = "none")]
 
-use core::alloc::LayoutError;
+use core::alloc::{LayoutError, GlobalCoAllocMeta};
 use core::cmp;
 use core::intrinsics;
 use core::mem::{self, ManuallyDrop, MaybeUninit, SizedTypeProperties};
@@ -53,6 +53,8 @@ pub(crate) struct RawVec<T, A: Allocator = Global> {
     ptr: Unique<T>,
     cap: usize,
     alloc: A,
+    #[allow(dead_code)]
+    pub(crate) meta: GlobalCoAllocMeta,
 }
 
 impl<T> RawVec<T, Global> {
@@ -120,7 +122,7 @@ impl<T, A: Allocator> RawVec<T, A> {
     /// the returned `RawVec`.
     pub const fn new_in(alloc: A) -> Self {
         // `cap: 0` means "unallocated". zero-sized types are ignored.
-        Self { ptr: Unique::dangling(), cap: 0, alloc }
+        Self { ptr: Unique::dangling(), cap: 0, alloc, meta: GlobalCoAllocMeta {/*one: 1*/ /* , two: 2, three: 3, four: 4*/} }
     }
 
     /// Like `with_capacity`, but parameterized over the choice of
@@ -197,6 +199,7 @@ impl<T, A: Allocator> RawVec<T, A> {
                 ptr: unsafe { Unique::new_unchecked(ptr.cast().as_ptr()) },
                 cap: capacity,
                 alloc,
+                meta: GlobalCoAllocMeta {/*one: 1*/ /*, two: 2, three: 3, four: 4*/}
             }
         }
     }
@@ -213,7 +216,7 @@ impl<T, A: Allocator> RawVec<T, A> {
     /// guaranteed.
     #[inline]
     pub unsafe fn from_raw_parts_in(ptr: *mut T, capacity: usize, alloc: A) -> Self {
-        Self { ptr: unsafe { Unique::new_unchecked(ptr) }, cap: capacity, alloc }
+        Self { ptr: unsafe { Unique::new_unchecked(ptr) }, cap: capacity, alloc, meta: GlobalCoAllocMeta {/*one: 1*/ /*, two: 2, three: 3, four: 4*/} }
     }
 
     /// Gets a raw pointer to the start of the allocation. Note that this is
@@ -473,8 +476,18 @@ where
 }
 
 unsafe impl<#[may_dangle] T, A: Allocator> Drop for RawVec<T, A> {
+    /// Frees the memory owned by the `RawVec` *without* trying to drop its contents.
+    default fn drop(&mut self) {
+        if let Some((ptr, layout)) = self.current_memory() {
+            unsafe { self.alloc.deallocate(ptr, layout) }
+        }
+    }
+}
+
+unsafe impl<#[may_dangle] T> Drop for RawVec<T, Global> {
     /// Frees the memory owned by the `RawVec` *without* trying to drop its contents.
     fn drop(&mut self) {
+        // @TODO
         if let Some((ptr, layout)) = self.current_memory() {
             unsafe { self.alloc.deallocate(ptr, layout) }
         }
diff --git a/library/core/src/alloc/global.rs b/library/core/src/alloc/global.rs
@@ -1,6 +1,15 @@
 use crate::alloc::Layout;
 use crate::cmp;
 use crate::ptr;
+use crate::alloc::GlobalCoAllocMeta;
+
+#[unstable(feature = "global_co_alloc_meta", issue = "none")]
+#[allow(missing_debug_implementations)]
+/// Used for parameters and results (to/from `GlobalCoAllocator`'s functions, where applicable).
+pub struct PtrAndMeta {
+    pub ptr: *mut u8,
+    pub meta: GlobalCoAllocMeta,
+}
 
 /// A memory allocator that can be registered as the standard library’s default
 /// through the `#[global_allocator]` attribute.
@@ -156,6 +165,9 @@ pub unsafe trait GlobalAlloc {
     #[stable(feature = "global_alloc", since = "1.28.0")]
     unsafe fn alloc(&self, layout: Layout) -> *mut u8;
 
+    #[unstable(feature = "global_co_alloc", issue = "none")]
+    unsafe fn co_alloc(&self, _layout: Layout, mut _result: &mut PtrAndMeta) {panic!("TODO")}
+
     /// Deallocate the block of memory at the given `ptr` pointer with the given `layout`.
     ///
     /// # Safety
@@ -171,6 +183,9 @@ pub unsafe trait GlobalAlloc {
     #[stable(feature = "global_alloc", since = "1.28.0")]
     unsafe fn dealloc(&self, ptr: *mut u8, layout: Layout);
 
+    #[unstable(feature = "global_co_alloc", issue = "none")]
+    unsafe fn co_dealloc(&self, _ptr_and_meta: PtrAndMeta, _layout: Layout) {panic!("TODO")}
+
     /// Behaves like `alloc`, but also ensures that the contents
     /// are set to zero before being returned.
     ///
@@ -198,11 +213,23 @@ pub unsafe trait GlobalAlloc {
         if !ptr.is_null() {
             // SAFETY: as allocation succeeded, the region from `ptr`
             // of size `size` is guaranteed to be valid for writes.
-            unsafe { ptr::write_bytes(ptr, 0, size) };
+            unsafe { ptr::write_bytes(ptr, 0u8, size) };
         }
         ptr
     }
 
+    #[unstable(feature = "global_co_alloc", issue = "none")]
+    unsafe fn co_alloc_zeroed(&self, layout: Layout, mut result: &mut PtrAndMeta) {
+        let size = layout.size();
+        // SAFETY: the safety contract for `alloc` must be upheld by the caller.
+        unsafe { self.co_alloc(layout, &mut result) };
+        if !result.ptr.is_null() {
+            // SAFETY: as allocation succeeded, the region from `ptr_and_meta.ptr` of size `size` is
+            // guaranteed to be valid for writes.
+            unsafe { ptr::write_bytes(result.ptr, 0u8, size) };
+        }
+    }
+
     /// Shrink or grow a block of memory to the given `new_size`.
     /// The block is described by the given `ptr` pointer and `layout`.
     ///
@@ -274,4 +301,31 @@ pub unsafe trait GlobalAlloc {
         }
         new_ptr
     }
+
+    #[unstable(feature = "global_co_alloc", issue = "none")]
+    unsafe fn co_realloc(
+        &self,
+        ptr_and_meta: PtrAndMeta,
+        layout: Layout,
+        new_size: usize,
+        mut result: &mut PtrAndMeta
+    ) {
+        // SAFETY: the caller must ensure that the `new_size` does not overflow.
+        // `layout.align()` comes from a `Layout` and is thus guaranteed to be valid.
+        let new_layout = unsafe { Layout::from_size_align_unchecked(new_size, layout.align()) };
+        // SAFETY: the caller must ensure that `new_layout` is greater than zero.
+        unsafe { self.co_alloc(new_layout, &mut result) };
+        if !result.ptr.is_null() {
+            // SAFETY: the previously allocated block cannot overlap the newly allocated block.
+            // The safety contract for `dealloc` must be upheld by the caller.
+            unsafe {
+                ptr::copy_nonoverlapping(
+                    ptr_and_meta.ptr,
+                    result.ptr,
+                    cmp::min(layout.size(), new_size),
+                );
+                self.co_dealloc(ptr_and_meta, layout);
+            }
+        }
+    }
 }
diff --git a/library/core/src/alloc/mod.rs b/library/core/src/alloc/mod.rs
@@ -3,6 +3,7 @@
 #![stable(feature = "alloc_module", since = "1.28.0")]
 
 mod global;
+//mod global_co;
 mod layout;
 
 #[stable(feature = "global_alloc", since = "1.28.0")]
@@ -25,6 +26,16 @@ use crate::error::Error;
 use crate::fmt;
 use crate::ptr::{self, NonNull};
 
+// @TODO Make this target-specific
+#[unstable(feature = "global_co_alloc_meta", issue = "none")]
+#[allow(missing_debug_implementations)]
+pub struct GlobalCoAllocMeta {
+    //pub one: usize,
+    /*pub two: usize,
+    pub three: usize,
+    pub four: usize,*/
+}
+
 /// The `AllocError` error indicates an allocation failure
 /// that may be due to resource exhaustion or to
 /// something wrong when combining the given input arguments with this
diff --git a/src/librustdoc/clean/types.rs b/src/librustdoc/clean/types.rs
@@ -1,6 +1,8 @@
+use std::alloc::GlobalCoAllocMeta;
 use std::cell::RefCell;
 use std::default::Default;
 use std::hash::Hash;
+use std::mem;
 use std::path::PathBuf;
 use std::rc::Rc;
 use std::sync::Arc;
@@ -2574,13 +2576,13 @@ mod size_asserts {
     // tidy-alphabetical-start
     static_assert_size!(Crate, 64); // frequently moved by-value
     static_assert_size!(DocFragment, 32);
-    static_assert_size!(GenericArg, 32);
+    static_assert_size!(GenericArg, 32 + mem::size_of::<GlobalCoAllocMeta>());
     static_assert_size!(GenericArgs, 32);
-    static_assert_size!(GenericParamDef, 56);
+    static_assert_size!(GenericParamDef, 56 + mem::size_of::<GlobalCoAllocMeta>());
     static_assert_size!(Generics, 16);
     static_assert_size!(Item, 56);
-    static_assert_size!(ItemKind, 64);
+    static_assert_size!(ItemKind, 64 + mem::size_of::<GlobalCoAllocMeta>());
     static_assert_size!(PathSegment, 40);
-    static_assert_size!(Type, 32);
+    static_assert_size!(Type, 32 + mem::size_of::<GlobalCoAllocMeta>());
     // tidy-alphabetical-end
 }
diff --git a/src/librustdoc/html/render/context.rs b/src/librustdoc/html/render/context.rs
diff --git a/src/librustdoc/lib.rs b/src/librustdoc/lib.rs
