forked from BigfootDev/flatbuffers
374f8fb5fb
* Rust soundness fixes * Second pass * Make init_from_table unsafe * Remove SafeSliceAccess * Clippy * Remove create_vector_of_strings * More clippy * Remove deprecated root type accessors * More soundness fixes * Fix EndianScalar for bool * Add TriviallyTransmutable * Add debug assertions * Review comments * Review feedback
101 lines
2.7 KiB
Rust
101 lines
2.7 KiB
Rust
/*
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* Copyright 2018 Google Inc. All rights reserved.
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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use core::cmp::max;
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use core::mem::{align_of, size_of};
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use crate::endian_scalar::emplace_scalar;
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/// Trait to abstract over functionality needed to write values (either owned
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/// or referenced). Used in FlatBufferBuilder and implemented for generated
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/// types.
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pub trait Push: Sized {
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type Output;
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/// # Safety
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///
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/// dst is aligned to [`Self::alignment`] and has length greater than or equal to [`Self::size`]
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unsafe fn push(&self, dst: &mut [u8], written_len: usize);
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#[inline]
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fn size() -> usize {
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size_of::<Self::Output>()
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}
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#[inline]
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fn alignment() -> PushAlignment {
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PushAlignment::new(align_of::<Self::Output>())
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}
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}
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impl<'a, T: Push> Push for &'a T {
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type Output = T::Output;
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unsafe fn push(&self, dst: &mut [u8], written_len: usize) {
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T::push(self, dst, written_len)
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}
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fn size() -> usize {
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T::size()
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}
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fn alignment() -> PushAlignment {
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T::alignment()
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}
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}
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/// Ensure Push alignment calculations are typesafe (because this helps reduce
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/// implementation issues when using FlatBufferBuilder::align).
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pub struct PushAlignment(usize);
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impl PushAlignment {
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#[inline]
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pub fn new(x: usize) -> Self {
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PushAlignment(x)
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}
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#[inline]
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pub fn value(&self) -> usize {
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self.0
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}
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#[inline]
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pub fn max_of(&self, o: usize) -> Self {
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PushAlignment::new(max(self.0, o))
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}
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}
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/// Macro to implement Push for EndianScalar types.
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macro_rules! impl_push_for_endian_scalar {
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($ty:ident) => {
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impl Push for $ty {
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type Output = $ty;
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#[inline]
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unsafe fn push(&self, dst: &mut [u8], _written_len: usize) {
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emplace_scalar::<$ty>(dst, *self);
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}
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}
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};
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}
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impl_push_for_endian_scalar!(bool);
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impl_push_for_endian_scalar!(u8);
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impl_push_for_endian_scalar!(i8);
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impl_push_for_endian_scalar!(u16);
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impl_push_for_endian_scalar!(i16);
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impl_push_for_endian_scalar!(u32);
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impl_push_for_endian_scalar!(i32);
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impl_push_for_endian_scalar!(u64);
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impl_push_for_endian_scalar!(i64);
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impl_push_for_endian_scalar!(f32);
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impl_push_for_endian_scalar!(f64);
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