Auto merge of #144572 - scottmcm:alloc-using-alignment, r=<try>

Need less bumf to pass `Layout` to `__rustc_alloc`

Author: rust-bors[bot]

library/alloc/src/alloc.rs

@@ -6,7 +6,7 @@
 #[doc(inline)]
 pub use core::alloc::*;
 use core::hint;
-use core::ptr::{self, NonNull};
+use core::ptr::{self, Alignment, NonNull};
 
 unsafe extern "Rust" {
     // These are the magic symbols to call the global allocator. rustc generates
@@ -17,19 +17,19 @@ unsafe extern "Rust" {
     #[rustc_allocator]
     #[rustc_nounwind]
     #[rustc_std_internal_symbol]
-    fn __rust_alloc(size: usize, align: usize) -> *mut u8;
+    fn __rust_alloc(size: usize, align: Alignment) -> *mut u8;
     #[rustc_deallocator]
     #[rustc_nounwind]
     #[rustc_std_internal_symbol]
-    fn __rust_dealloc(ptr: *mut u8, size: usize, align: usize);
+    fn __rust_dealloc(ptr: *mut u8, size: usize, align: Alignment);
     #[rustc_reallocator]
     #[rustc_nounwind]
     #[rustc_std_internal_symbol]
-    fn __rust_realloc(ptr: *mut u8, old_size: usize, align: usize, new_size: usize) -> *mut u8;
+    fn __rust_realloc(ptr: *mut u8, old_size: usize, align: Alignment, new_size: usize) -> *mut u8;
     #[rustc_allocator_zeroed]
     #[rustc_nounwind]
     #[rustc_std_internal_symbol]
-    fn __rust_alloc_zeroed(size: usize, align: usize) -> *mut u8;
+    fn __rust_alloc_zeroed(size: usize, align: Alignment) -> *mut u8;
 
     #[rustc_nounwind]
     #[rustc_std_internal_symbol]
@@ -91,7 +91,7 @@ pub unsafe fn alloc(layout: Layout) -> *mut u8 {
         // stable code until it is actually stabilized.
         __rust_no_alloc_shim_is_unstable_v2();
 
-        __rust_alloc(layout.size(), layout.align())
+        __rust_alloc(layout.size(), layout.alignment())
     }
 }
 
@@ -111,7 +111,7 @@ pub unsafe fn alloc(layout: Layout) -> *mut u8 {
 #[inline]
 #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces
 pub unsafe fn dealloc(ptr: *mut u8, layout: Layout) {
-    unsafe { __rust_dealloc(ptr, layout.size(), layout.align()) }
+    unsafe { __rust_dealloc(ptr, layout.size(), layout.alignment()) }
 }
 
 /// Reallocates memory with the global allocator.
@@ -131,7 +131,7 @@ pub unsafe fn dealloc(ptr: *mut u8, layout: Layout) {
 #[inline]
 #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces
 pub unsafe fn realloc(ptr: *mut u8, layout: Layout, new_size: usize) -> *mut u8 {
-    unsafe { __rust_realloc(ptr, layout.size(), layout.align(), new_size) }
+    unsafe { __rust_realloc(ptr, layout.size(), layout.alignment(), new_size) }
 }
 
 /// Allocates zero-initialized memory with the global allocator.
@@ -174,7 +174,7 @@ pub unsafe fn alloc_zeroed(layout: Layout) -> *mut u8 {
         // stable code until it is actually stabilized.
         __rust_no_alloc_shim_is_unstable_v2();
 
-        __rust_alloc_zeroed(layout.size(), layout.align())
+        __rust_alloc_zeroed(layout.size(), layout.alignment())
     }
 }
 

tests/codegen-llvm/box-uninit-bytes.rs

@@ -41,6 +41,6 @@ pub fn box_lotsa_padding() -> Box<LotsaPadding> {
 
 // Hide the `allocalign` attribute in the declaration of __rust_alloc
 // from the CHECK-NOT above, and also verify the attributes got set reasonably.
-// CHECK: declare {{(dso_local )?}}noalias noundef ptr @{{.*}}__rust_alloc(i{{[0-9]+}} noundef, i{{[0-9]+}} allocalign noundef) unnamed_addr [[RUST_ALLOC_ATTRS:#[0-9]+]]
+// CHECK: declare {{(dso_local )?}}noalias noundef ptr @{{.*}}__rust_alloc(i{{[0-9]+}} noundef, i{{[0-9]+}} allocalign noundef range({{i64 1, -9223372036854775807|i32 1, -2147483647}})) unnamed_addr [[RUST_ALLOC_ATTRS:#[0-9]+]]
 
 // CHECK-DAG: attributes [[RUST_ALLOC_ATTRS]] = { {{.*}} allockind("alloc,uninitialized,aligned") allocsize(0) {{(uwtable )?}}"alloc-family"="__rust_alloc" {{.*}} }

tests/codegen-llvm/vec-calloc.rs

@@ -177,6 +177,6 @@ pub fn vec_option_i32(n: usize) -> Vec<Option<i32>> {
 }
 
 // Ensure that __rust_alloc_zeroed gets the right attributes for LLVM to optimize it away.
-// CHECK: declare noalias noundef ptr @{{.*}}__rust_alloc_zeroed(i64 noundef, i64 allocalign noundef) unnamed_addr [[RUST_ALLOC_ZEROED_ATTRS:#[0-9]+]]
+// CHECK: declare noalias noundef ptr @{{.*}}__rust_alloc_zeroed(i64 noundef, i64 allocalign noundef range(i64 1, -9223372036854775807)) unnamed_addr [[RUST_ALLOC_ZEROED_ATTRS:#[0-9]+]]
 
 // CHECK-DAG: attributes [[RUST_ALLOC_ZEROED_ATTRS]] = { {{.*}} allockind("alloc,zeroed,aligned") allocsize(0) uwtable "alloc-family"="__rust_alloc" {{.*}} }

tests/mir-opt/pre-codegen/drop_boxed_slice.generic_in_place.PreCodegen.after.panic-abort.mir

@@ -0,0 +1,97 @@
+// MIR for `generic_in_place` after PreCodegen
+
+fn generic_in_place(_1: *mut Box<[T]>) -> () {
+    debug ptr => _1;
+    let mut _0: ();
+    scope 1 (inlined drop_in_place::<Box<[T]>> - shim(Some(Box<[T]>))) {
+        scope 2 (inlined <Box<[T]> as Drop>::drop) {
+            let _2: std::ptr::NonNull<[T]>;
+            let mut _3: *mut [T];
+            let mut _4: *const [T];
+            let _9: ();
+            scope 3 {
+                scope 4 {
+                    scope 12 (inlined Layout::size) {
+                    }
+                    scope 13 (inlined Unique::<[T]>::cast::<u8>) {
+                        scope 14 (inlined NonNull::<[T]>::cast::<u8>) {
+                            scope 15 (inlined NonNull::<[T]>::as_ptr) {
+                            }
+                        }
+                    }
+                    scope 16 (inlined <NonNull<u8> as From<Unique<u8>>>::from) {
+                        scope 17 (inlined Unique::<u8>::as_non_null_ptr) {
+                        }
+                    }
+                    scope 18 (inlined <std::alloc::Global as Allocator>::deallocate) {
+                        let mut _8: *mut u8;
+                        scope 19 (inlined Layout::size) {
+                        }
+                        scope 20 (inlined NonNull::<u8>::as_ptr) {
+                        }
+                        scope 21 (inlined std::alloc::dealloc) {
+                            scope 22 (inlined Layout::size) {
+                            }
+                            scope 23 (inlined Layout::alignment) {
+                            }
+                        }
+                    }
+                }
+                scope 5 (inlined Unique::<[T]>::as_ptr) {
+                    scope 6 (inlined NonNull::<[T]>::as_ptr) {
+                    }
+                }
+                scope 7 (inlined Layout::for_value_raw::<[T]>) {
+                    let mut _5: usize;
+                    let mut _6: usize;
+                    scope 8 {
+                        scope 11 (inlined #[track_caller] Layout::from_size_align_unchecked) {
+                            let mut _7: std::ptr::Alignment;
+                        }
+                    }
+                    scope 9 (inlined size_of_val_raw::<[T]>) {
+                    }
+                    scope 10 (inlined align_of_val_raw::<[T]>) {
+                    }
+                }
+            }
+        }
+    }
+
+    bb0: {
+        StorageLive(_2);
+        _2 = copy (((*_1).0: std::ptr::Unique<[T]>).0: std::ptr::NonNull<[T]>);
+        StorageLive(_4);
+        _3 = copy _2 as *mut [T] (Transmute);
+        _4 = copy _2 as *const [T] (Transmute);
+        StorageLive(_6);
+        _5 = std::intrinsics::size_of_val::<[T]>(copy _4) -> [return: bb1, unwind unreachable];
+    }
+
+    bb1: {
+        _6 = std::intrinsics::align_of_val::<[T]>(move _4) -> [return: bb2, unwind unreachable];
+    }
+
+    bb2: {
+        _7 = copy _6 as std::ptr::Alignment (Transmute);
+        StorageDead(_6);
+        StorageDead(_4);
+        switchInt(copy _5) -> [0: bb5, otherwise: bb3];
+    }
+
+    bb3: {
+        StorageLive(_8);
+        _8 = copy _3 as *mut u8 (PtrToPtr);
+        _9 = alloc::alloc::__rust_dealloc(move _8, move _5, move _7) -> [return: bb4, unwind unreachable];
+    }
+
+    bb4: {
+        StorageDead(_8);
+        goto -> bb5;
+    }
+
+    bb5: {
+        StorageDead(_2);
+        return;
+    }
+}

tests/mir-opt/pre-codegen/drop_boxed_slice.generic_in_place.PreCodegen.after.panic-unwind.mir

@@ -0,0 +1,97 @@
+// MIR for `generic_in_place` after PreCodegen
+
+fn generic_in_place(_1: *mut Box<[T]>) -> () {
+    debug ptr => _1;
+    let mut _0: ();
+    scope 1 (inlined drop_in_place::<Box<[T]>> - shim(Some(Box<[T]>))) {
+        scope 2 (inlined <Box<[T]> as Drop>::drop) {
+            let _2: std::ptr::NonNull<[T]>;
+            let mut _3: *mut [T];
+            let mut _4: *const [T];
+            let _9: ();
+            scope 3 {
+                scope 4 {
+                    scope 12 (inlined Layout::size) {
+                    }
+                    scope 13 (inlined Unique::<[T]>::cast::<u8>) {
+                        scope 14 (inlined NonNull::<[T]>::cast::<u8>) {
+                            scope 15 (inlined NonNull::<[T]>::as_ptr) {
+                            }
+                        }
+                    }
+                    scope 16 (inlined <NonNull<u8> as From<Unique<u8>>>::from) {
+                        scope 17 (inlined Unique::<u8>::as_non_null_ptr) {
+                        }
+                    }
+                    scope 18 (inlined <std::alloc::Global as Allocator>::deallocate) {
+                        let mut _8: *mut u8;
+                        scope 19 (inlined Layout::size) {
+                        }
+                        scope 20 (inlined NonNull::<u8>::as_ptr) {
+                        }
+                        scope 21 (inlined std::alloc::dealloc) {
+                            scope 22 (inlined Layout::size) {
+                            }
+                            scope 23 (inlined Layout::alignment) {
+                            }
+                        }
+                    }
+                }
+                scope 5 (inlined Unique::<[T]>::as_ptr) {
+                    scope 6 (inlined NonNull::<[T]>::as_ptr) {
+                    }
+                }
+                scope 7 (inlined Layout::for_value_raw::<[T]>) {
+                    let mut _5: usize;
+                    let mut _6: usize;
+                    scope 8 {
+                        scope 11 (inlined #[track_caller] Layout::from_size_align_unchecked) {
+                            let mut _7: std::ptr::Alignment;
+                        }
+                    }
+                    scope 9 (inlined size_of_val_raw::<[T]>) {
+                    }
+                    scope 10 (inlined align_of_val_raw::<[T]>) {
+                    }
+                }
+            }
+        }
+    }
+
+    bb0: {
+        StorageLive(_2);
+        _2 = copy (((*_1).0: std::ptr::Unique<[T]>).0: std::ptr::NonNull<[T]>);
+        StorageLive(_4);
+        _3 = copy _2 as *mut [T] (Transmute);
+        _4 = copy _2 as *const [T] (Transmute);
+        StorageLive(_6);
+        _5 = std::intrinsics::size_of_val::<[T]>(copy _4) -> [return: bb1, unwind unreachable];
+    }
+
+    bb1: {
+        _6 = std::intrinsics::align_of_val::<[T]>(move _4) -> [return: bb2, unwind unreachable];
+    }
+
+    bb2: {
+        _7 = copy _6 as std::ptr::Alignment (Transmute);
+        StorageDead(_6);
+        StorageDead(_4);
+        switchInt(copy _5) -> [0: bb5, otherwise: bb3];
+    }
+
+    bb3: {
+        StorageLive(_8);
+        _8 = copy _3 as *mut u8 (PtrToPtr);
+        _9 = alloc::alloc::__rust_dealloc(move _8, move _5, move _7) -> [return: bb4, unwind unreachable];
+    }
+
+    bb4: {
+        StorageDead(_8);
+        goto -> bb5;
+    }
+
+    bb5: {
+        StorageDead(_2);
+        return;
+    }
+}

tests/mir-opt/pre-codegen/drop_boxed_slice.rs

@@ -0,0 +1,18 @@
+//@ compile-flags: -O -Zmir-opt-level=2
+// EMIT_MIR_FOR_EACH_PANIC_STRATEGY
+
+#![crate_type = "lib"]
+#![feature(step_trait)]
+
+// EMIT_MIR drop_boxed_slice.generic_in_place.PreCodegen.after.mir
+pub unsafe fn generic_in_place<T: Copy>(ptr: *mut Box<[T]>) {
+    // CHECK-LABEL: fn generic_in_place(_1: *mut Box<[T]>)
+    // CHECK: (inlined <Box<[T]> as Drop>::drop)
+    // CHECK: [[SIZE:_.+]] = std::intrinsics::size_of_val::<[T]>
+    // CHECK: [[ALIGN:_.+]] = std::intrinsics::align_of_val::<[T]>
+    // CHECK: [[ALIGNMENT:_.+]] = copy [[ALIGN]] as std::ptr::Alignment (Transmute);
+    // CHECK-NOT: discriminant
+    // CHECK-NOT: IntToInt
+    // CHECK: = alloc::alloc::__rust_dealloc({{.+}}, move [[SIZE]], move [[ALIGNMENT]]) ->
+    std::ptr::drop_in_place(ptr)
+}