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A fingerprint is a stable hash of a particular piece of compiler data. This formalizes the stable notion of identity that the dependency trackers use for type body fingerprints in iterable decl contexts and the file-level interface hash
44 lines
1.6 KiB
C++
44 lines
1.6 KiB
C++
//===--- Fingerprint.cpp - A stable identity for compiler data --*- C++ -*-===//
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//
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// This source file is part of the Swift.org open source project
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//
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// Copyright (c) 2014 - 2020 Apple Inc. and the Swift project authors
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// Licensed under Apache License v2.0 with Runtime Library Exception
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//
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// See https://swift.org/LICENSE.txt for license information
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// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
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//
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//===----------------------------------------------------------------------===//
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#include "swift/Basic/Fingerprint.h"
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#include "swift/Basic/STLExtras.h"
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#include "llvm/Support/raw_ostream.h"
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using namespace swift;
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llvm::raw_ostream &llvm::operator<<(llvm::raw_ostream &OS,
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const Fingerprint &FP) {
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return OS << FP.getRawValue();
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}
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void swift::simple_display(llvm::raw_ostream &out, const Fingerprint &fp) {
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out << fp.getRawValue();
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}
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namespace {
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template <class T> struct SmallStringBound;
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template <size_t N> struct SmallStringBound<llvm::SmallString<N>> {
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static constexpr size_t value = N;
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};
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};
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// Assert that the \c DIGEST_LENGTH value we export from the \c Fingerprint
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// has the right byte length. It's unlikely this value will change in LLVM,
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// but it's always good to have compile-time justification for a
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// magic constant - especially one that gets used for serialization.
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using MD5Digest_t =
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decltype (&llvm::MD5::MD5Result::digest)(llvm::MD5::MD5Result);
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static_assert(SmallStringBound<std::result_of<MD5Digest_t>::type>::value ==
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Fingerprint::DIGEST_LENGTH,
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"MD5 digest size does not match size expected by Fingerprint!");
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