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//===--------------- BitCode.swift - LLVM BitCode Helpers ----------------===//
//
// This source file is part of the Swift.org open source project
//
// Copyright (c) 2014 - 2019 Apple Inc. and the Swift project authors
// Licensed under Apache License v2.0 with Runtime Library Exception
//
// See https://swift.org/LICENSE.txt for license information
// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
//
//===----------------------------------------------------------------------===//
import struct TSCBasic.ByteString
internal struct Bitcode {
public let signature: Bitcode.Signature
public let elements: [BitcodeElement]
public let blockInfo: [UInt64:BlockInfo]
}
extension Bitcode {
internal struct Signature: Equatable {
private var value: UInt32
public init(value: UInt32) {
self.value = value
}
public init(string: String) {
precondition(string.utf8.count == 4)
var result: UInt32 = 0
for byte in string.utf8.reversed() {
result <<= 8
result |= UInt32(byte)
}
self.value = result
}
}
}
extension Bitcode {
/// Traverse a bitstream using the specified `visitor`, which will receive
/// callbacks when blocks and records are encountered.
internal static func read<Visitor: BitstreamVisitor>(bytes: ByteString, using visitor: inout Visitor) throws {
precondition(bytes.count > 4)
var reader = BitstreamReader(buffer: bytes)
try visitor.validate(signature: reader.readSignature())
try reader.readBlock(id: BitstreamReader.fakeTopLevelBlockID,
abbrevWidth: 2,
abbrevInfo: [],
visitor: &visitor)
}
}
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