diff options
| -rw-r--r-- | components/servo_arc/lib.rs | 29 | ||||
| -rw-r--r-- | components/style/gecko/profiler.rs | 6 | ||||
| -rw-r--r-- | components/style/gecko_string_cache/mod.rs | 6 | ||||
| -rw-r--r-- | components/style/macros.rs | 4 | ||||
| -rw-r--r-- | components/style/properties/gecko.mako.rs | 17 | ||||
| -rw-r--r-- | components/style/properties/helpers/animated_properties.mako.rs | 32 | ||||
| -rw-r--r-- | components/style/properties/longhands/font.mako.rs | 13 | ||||
| -rw-r--r-- | components/style/properties/properties.mako.rs | 14 | ||||
| -rw-r--r-- | components/to_shmem/lib.rs | 7 |
9 files changed, 60 insertions, 68 deletions
diff --git a/components/servo_arc/lib.rs b/components/servo_arc/lib.rs index 089aa60f031..6e86ea7b5f3 100644 --- a/components/servo_arc/lib.rs +++ b/components/servo_arc/lib.rs @@ -52,25 +52,6 @@ use std::sync::atomic; use std::sync::atomic::Ordering::{Acquire, Relaxed, Release}; use std::{isize, usize}; -// Private macro to get the offset of a struct field in bytes from the address of the struct. -macro_rules! offset_of { - ($container:path, $field:ident) => {{ - // Make sure the field actually exists. This line ensures that a compile-time error is - // generated if $field is accessed through a Deref impl. - let $container { $field: _, .. }; - - // Create an (invalid) instance of the container and calculate the offset to its - // field. Using a null pointer might be UB if `&(*(0 as *const T)).field` is interpreted to - // be nullptr deref. - let invalid: $container = ::std::mem::uninitialized(); - let offset = &invalid.$field as *const _ as usize - &invalid as *const _ as usize; - - // Do not run destructors on the made up invalid instance. - ::std::mem::forget(invalid); - offset as isize - }}; -} - /// A soft limit on the amount of references that may be made to an `Arc`. /// /// Going above this limit will abort your program (although not @@ -196,6 +177,14 @@ struct ArcInner<T: ?Sized> { unsafe impl<T: ?Sized + Sync + Send> Send for ArcInner<T> {} unsafe impl<T: ?Sized + Sync + Send> Sync for ArcInner<T> {} +/// Computes the offset of the data field within ArcInner. +fn data_offset<T>() -> usize { + let size = size_of::<ArcInner<()>>(); + let align = align_of::<T>(); + // https://github.com/rust-lang/rust/blob/1.36.0/src/libcore/alloc.rs#L187-L207 + size.wrapping_add(align).wrapping_sub(1) & !align.wrapping_sub(1) +} + impl<T> Arc<T> { /// Construct an `Arc<T>` #[inline] @@ -251,7 +240,7 @@ impl<T> Arc<T> { unsafe fn from_raw(ptr: *const T) -> Self { // To find the corresponding pointer to the `ArcInner` we need // to subtract the offset of the `data` field from the pointer. - let ptr = (ptr as *const u8).offset(-offset_of!(ArcInner<T>, data)); + let ptr = (ptr as *const u8).sub(data_offset::<T>()); Arc { p: ptr::NonNull::new_unchecked(ptr as *mut ArcInner<T>), phantom: PhantomData, diff --git a/components/style/gecko/profiler.rs b/components/style/gecko/profiler.rs index 1f25dde04e7..db269b497d1 100644 --- a/components/style/gecko/profiler.rs +++ b/components/style/gecko/profiler.rs @@ -29,15 +29,15 @@ impl<'a> AutoProfilerLabel<'a> { /// stack. #[inline] pub unsafe fn new( - label: &mut structs::AutoProfilerLabel, + label: &mut std::mem::MaybeUninit<structs::AutoProfilerLabel>, label_type: ProfilerLabel, ) -> AutoProfilerLabel { let category_pair = match label_type { ProfilerLabel::Style => structs::JS::ProfilingCategoryPair_LAYOUT_StyleComputation, ProfilerLabel::Parse => structs::JS::ProfilingCategoryPair_LAYOUT_CSSParsing, }; - structs::Gecko_Construct_AutoProfilerLabel(label, category_pair); - AutoProfilerLabel(label) + structs::Gecko_Construct_AutoProfilerLabel(label.as_mut_ptr(), category_pair); + AutoProfilerLabel(&mut *label.as_mut_ptr()) } } diff --git a/components/style/gecko_string_cache/mod.rs b/components/style/gecko_string_cache/mod.rs index b8f3ff7f048..b209f316d09 100644 --- a/components/style/gecko_string_cache/mod.rs +++ b/components/style/gecko_string_cache/mod.rs @@ -202,7 +202,8 @@ impl WeakAtom { where F: FnOnce(&str) -> Output, { - let mut buffer: [u8; 64] = unsafe { mem::uninitialized() }; + let mut buffer = mem::MaybeUninit::<[u8; 64]>::uninit(); + let buffer = unsafe { &mut *buffer.as_mut_ptr() }; // The total string length in utf16 is going to be less than or equal // the slice length (each utf16 character is going to take at least one @@ -271,7 +272,8 @@ impl WeakAtom { } let slice = self.as_slice(); - let mut buffer: [u16; 64] = unsafe { mem::uninitialized() }; + let mut buffer = mem::MaybeUninit::<[u16; 64]>::uninit(); + let buffer = unsafe { &mut *buffer.as_mut_ptr() }; let mut vec; let mutable_slice = if let Some(buffer_prefix) = buffer.get_mut(..slice.len()) { buffer_prefix.copy_from_slice(slice); diff --git a/components/style/macros.rs b/components/style/macros.rs index 229e864977a..b4f4f1f7caf 100644 --- a/components/style/macros.rs +++ b/components/style/macros.rs @@ -112,8 +112,8 @@ macro_rules! define_keyword_type { #[macro_export] macro_rules! profiler_label { ($label_type:ident) => { - let mut _profiler_label: $crate::gecko_bindings::structs::AutoProfilerLabel = - unsafe { ::std::mem::uninitialized() }; + let mut _profiler_label = + ::std::mem::MaybeUninit::<$crate::gecko_bindings::structs::AutoProfilerLabel>::uninit(); let _profiler_label = if $crate::gecko::profiler::profiler_is_active() { unsafe { Some($crate::gecko::profiler::AutoProfilerLabel::new( diff --git a/components/style/properties/gecko.mako.rs b/components/style/properties/gecko.mako.rs index 11bd30136d7..ec29b82f2df 100644 --- a/components/style/properties/gecko.mako.rs +++ b/components/style/properties/gecko.mako.rs @@ -44,9 +44,9 @@ use crate::properties::computed_value_flags::*; use crate::properties::longhands; use crate::rule_tree::StrongRuleNode; use crate::selector_parser::PseudoElement; -use servo_arc::{Arc, RawOffsetArc}; +use servo_arc::{Arc, RawOffsetArc, UniqueArc}; use std::marker::PhantomData; -use std::mem::{forget, uninitialized, zeroed, ManuallyDrop}; +use std::mem::{forget, zeroed, ManuallyDrop}; use std::{cmp, ops, ptr}; use crate::values::{self, CustomIdent, Either, KeyframesName, None_}; use crate::values::computed::{Percentage, TransitionProperty}; @@ -210,19 +210,18 @@ impl ComputedValuesInner { Some(p) => p.pseudo_type(), None => structs::PseudoStyleType::NotPseudo, }; - let arc = unsafe { - let arc: Arc<ComputedValues> = Arc::new(uninitialized()); + unsafe { + let mut arc = UniqueArc::<ComputedValues>::new_uninit(); bindings::Gecko_ComputedStyle_Init( - &arc.0 as *const _ as *mut _, + &mut (*arc.as_mut_ptr()).0, &self, pseudo_ty, ); - // We're simulating a move by having C++ do a memcpy and then forgetting + // We're simulating move semantics by having C++ do a memcpy and then forgetting // it on this end. forget(self); - arc - }; - arc + UniqueArc::assume_init(arc).shareable() + } } } diff --git a/components/style/properties/helpers/animated_properties.mako.rs b/components/style/properties/helpers/animated_properties.mako.rs index 48f499c7ec3..2dcaf5d3fb2 100644 --- a/components/style/properties/helpers/animated_properties.mako.rs +++ b/components/style/properties/helpers/animated_properties.mako.rs @@ -18,7 +18,7 @@ use crate::properties::LonghandId; use servo_arc::Arc; use smallvec::SmallVec; use std::ptr; -use std::mem::{self, ManuallyDrop}; +use std::mem; use crate::hash::FxHashMap; use super::ComputedValues; use crate::values::animated::{Animate, Procedure, ToAnimatedValue, ToAnimatedZero}; @@ -252,12 +252,12 @@ impl Clone for AnimationValue { } unsafe { - let mut out = mem::uninitialized(); + let mut out = mem::MaybeUninit::uninit(); ptr::write( - &mut out as *mut _ as *mut CopyVariants, + out.as_mut_ptr() as *mut CopyVariants, *(self as *const _ as *const CopyVariants), ); - return out; + return out.assume_init(); } } @@ -269,15 +269,15 @@ impl Clone for AnimationValue { ${props[0].camel_case}(value.clone()) % else: unsafe { - let mut out = ManuallyDrop::new(mem::uninitialized()); + let mut out = mem::MaybeUninit::uninit(); ptr::write( - &mut out as *mut _ as *mut AnimationValueVariantRepr<${ty}>, + out.as_mut_ptr() as *mut AnimationValueVariantRepr<${ty}>, AnimationValueVariantRepr { tag: *(self as *const _ as *const u16), value: value.clone(), }, ); - ManuallyDrop::into_inner(out) + out.assume_init() } % endif } @@ -356,15 +356,15 @@ impl AnimationValue { PropertyDeclaration::${props[0].camel_case}(value) % else: unsafe { - let mut out = mem::uninitialized(); + let mut out = mem::MaybeUninit::uninit(); ptr::write( - &mut out as *mut _ as *mut PropertyDeclarationVariantRepr<${specified}>, + out.as_mut_ptr() as *mut PropertyDeclarationVariantRepr<${specified}>, PropertyDeclarationVariantRepr { tag: *(self as *const _ as *const u16), value, }, ); - out + out.assume_init() } % endif } @@ -424,15 +424,15 @@ impl AnimationValue { % endif unsafe { - let mut out = mem::uninitialized(); + let mut out = mem::MaybeUninit::uninit(); ptr::write( - &mut out as *mut _ as *mut AnimationValueVariantRepr<${ty}>, + out.as_mut_ptr() as *mut AnimationValueVariantRepr<${ty}>, AnimationValueVariantRepr { tag: longhand_id.to_physical(context.builder.writing_mode) as u16, value, }, ); - out + out.assume_init() } } % endfor @@ -579,15 +579,15 @@ impl Animate for AnimationValue { let value = this.animate(&other_repr.value, procedure)?; % endif - let mut out = mem::uninitialized(); + let mut out = mem::MaybeUninit::uninit(); ptr::write( - &mut out as *mut _ as *mut AnimationValueVariantRepr<${ty}>, + out.as_mut_ptr() as *mut AnimationValueVariantRepr<${ty}>, AnimationValueVariantRepr { tag: this_tag, value, }, ); - out + out.assume_init() } % endfor ${" |\n".join("{}(void)".format(prop.camel_case) for prop in unanimated)} => { diff --git a/components/style/properties/longhands/font.mako.rs b/components/style/properties/longhands/font.mako.rs index d65afad693d..02a4fd03c7d 100644 --- a/components/style/properties/longhands/font.mako.rs +++ b/components/style/properties/longhands/font.mako.rs @@ -390,15 +390,16 @@ ${helpers.predefined_type( % endfor }; - let mut system: nsFont = unsafe { mem::uninitialized() }; - unsafe { + let mut system = mem::MaybeUninit::<nsFont>::uninit(); + let system = unsafe { bindings::Gecko_nsFont_InitSystem( - &mut system, + system.as_mut_ptr(), id as i32, cx.style().get_font().gecko(), cx.device().document() - ) - } + ); + &mut *system.as_mut_ptr() + }; let font_weight = longhands::font_weight::computed_value::T::from_gecko_weight(system.weight); let font_stretch = FontStretch(NonNegative(Percentage(unsafe { bindings::Gecko_FontStretch_ToFloat(system.stretch) @@ -436,7 +437,7 @@ ${helpers.predefined_type( system_font: *self, default_font_type: system.fontlist.mDefaultFontType, }; - unsafe { bindings::Gecko_nsFont_Destroy(&mut system); } + unsafe { bindings::Gecko_nsFont_Destroy(system); } ret } diff --git a/components/style/properties/properties.mako.rs b/components/style/properties/properties.mako.rs index 4f07d6feb84..6382ae8b250 100644 --- a/components/style/properties/properties.mako.rs +++ b/components/style/properties/properties.mako.rs @@ -17,7 +17,7 @@ use servo_arc::{Arc, UniqueArc}; use std::borrow::Cow; use std::{ops, ptr}; use std::fmt::{self, Write}; -use std::mem::{self, ManuallyDrop}; +use std::mem; use cssparser::{Parser, RGBA, TokenSerializationType}; use cssparser::ParserInput; @@ -294,12 +294,12 @@ impl Clone for PropertyDeclaration { } unsafe { - let mut out = mem::uninitialized(); + let mut out = mem::MaybeUninit::uninit(); ptr::write( - &mut out as *mut _ as *mut CopyVariants, + out.as_mut_ptr() as *mut CopyVariants, *(self as *const _ as *const CopyVariants), ); - return out; + return out.assume_init(); } } @@ -333,15 +333,15 @@ impl Clone for PropertyDeclaration { % else: ${" |\n".join("{}(ref value)".format(v["name"]) for v in vs)} => { unsafe { - let mut out = ManuallyDrop::new(mem::uninitialized()); + let mut out = mem::MaybeUninit::uninit(); ptr::write( - &mut out as *mut _ as *mut PropertyDeclarationVariantRepr<${ty}>, + out.as_mut_ptr() as *mut PropertyDeclarationVariantRepr<${ty}>, PropertyDeclarationVariantRepr { tag: *(self as *const _ as *const u16), value: value.clone(), }, ); - ManuallyDrop::into_inner(out) + out.assume_init() } } % endif diff --git a/components/to_shmem/lib.rs b/components/to_shmem/lib.rs index 07c5fc9ccaa..22b86087bfd 100644 --- a/components/to_shmem/lib.rs +++ b/components/to_shmem/lib.rs @@ -412,9 +412,10 @@ impl<T: ToShmem, A: Array<Item = T>> ToShmem for SmallVec<A> { SmallVec::from_raw_parts(dest, self.len(), self.len()) } else { // Place the items inline. - let mut inline: A = mem::uninitialized(); - to_shmem_slice_ptr(self.iter(), inline.ptr_mut(), builder); - SmallVec::from_buf_and_len(inline, self.len()) + let mut s = SmallVec::new(); + to_shmem_slice_ptr(self.iter(), s.as_mut_ptr(), builder); + s.set_len(self.len()); + s } }; |