42 lines
1.7 KiB
Swift
42 lines
1.7 KiB
Swift
// MIT License
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//
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// Copyright (c) 2017-2021 Wesley Wickwire and Tokamak contributors
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//
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// Permission is hereby granted, free of charge, to any person obtaining a copy
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// of this software and associated documentation files (the "Software"), to deal
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// in the Software without restriction, including without limitation the rights
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// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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// copies of the Software, and to permit persons to whom the Software is
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// furnished to do so, subject to the following conditions:
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//
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// The above copyright notice and this permission notice shall be included in all
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// copies or substantial portions of the Software.
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//
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// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
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// SOFTWARE.
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struct MetadataOffset<Pointee> {
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let offset: Int32
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func apply(to ptr: UnsafeRawPointer) -> UnsafePointer<Pointee> {
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// Data pointers in constant metadata are absolute until SwiftWasm 5.6
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// Since SwiftWasm 5.7, they are relative as well as other platforms.
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#if arch(wasm32) && !compiler(>=5.7)
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return UnsafePointer<Pointee>(bitPattern: Int(offset))!
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#else
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return ptr.advanced(by: numericCast(offset)).assumingMemoryBound(to: Pointee.self)
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#endif
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}
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}
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extension MetadataOffset: CustomStringConvertible {
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var description: String {
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"\(offset)"
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}
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}
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