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-rw-r--r--contrib/llvm/lib/DebugInfo/PDB/Native/HashTable.cpp308
1 files changed, 308 insertions, 0 deletions
diff --git a/contrib/llvm/lib/DebugInfo/PDB/Native/HashTable.cpp b/contrib/llvm/lib/DebugInfo/PDB/Native/HashTable.cpp
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+++ b/contrib/llvm/lib/DebugInfo/PDB/Native/HashTable.cpp
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+//===- HashTable.cpp - PDB Hash Table -------------------------------------===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/DebugInfo/PDB/Native/HashTable.h"
+#include "llvm/ADT/Optional.h"
+#include "llvm/DebugInfo/PDB/Native/RawError.h"
+#include "llvm/Support/BinaryStreamReader.h"
+#include "llvm/Support/BinaryStreamWriter.h"
+#include "llvm/Support/Error.h"
+#include "llvm/Support/MathExtras.h"
+#include <algorithm>
+#include <cassert>
+#include <cstdint>
+#include <utility>
+
+using namespace llvm;
+using namespace llvm::pdb;
+
+HashTable::HashTable() : HashTable(8) {}
+
+HashTable::HashTable(uint32_t Capacity) { Buckets.resize(Capacity); }
+
+Error HashTable::load(BinaryStreamReader &Stream) {
+ const Header *H;
+ if (auto EC = Stream.readObject(H))
+ return EC;
+ if (H->Capacity == 0)
+ return make_error<RawError>(raw_error_code::corrupt_file,
+ "Invalid Hash Table Capacity");
+ if (H->Size > maxLoad(H->Capacity))
+ return make_error<RawError>(raw_error_code::corrupt_file,
+ "Invalid Hash Table Size");
+
+ Buckets.resize(H->Capacity);
+
+ if (auto EC = readSparseBitVector(Stream, Present))
+ return EC;
+ if (Present.count() != H->Size)
+ return make_error<RawError>(raw_error_code::corrupt_file,
+ "Present bit vector does not match size!");
+
+ if (auto EC = readSparseBitVector(Stream, Deleted))
+ return EC;
+ if (Present.intersects(Deleted))
+ return make_error<RawError>(raw_error_code::corrupt_file,
+ "Present bit vector interesects deleted!");
+
+ for (uint32_t P : Present) {
+ if (auto EC = Stream.readInteger(Buckets[P].first))
+ return EC;
+ if (auto EC = Stream.readInteger(Buckets[P].second))
+ return EC;
+ }
+
+ return Error::success();
+}
+
+uint32_t HashTable::calculateSerializedLength() const {
+ uint32_t Size = sizeof(Header);
+
+ int NumBitsP = Present.find_last() + 1;
+ int NumBitsD = Deleted.find_last() + 1;
+
+ // Present bit set number of words, followed by that many actual words.
+ Size += sizeof(uint32_t);
+ Size += alignTo(NumBitsP, sizeof(uint32_t));
+
+ // Deleted bit set number of words, followed by that many actual words.
+ Size += sizeof(uint32_t);
+ Size += alignTo(NumBitsD, sizeof(uint32_t));
+
+ // One (Key, Value) pair for each entry Present.
+ Size += 2 * sizeof(uint32_t) * size();
+
+ return Size;
+}
+
+Error HashTable::commit(BinaryStreamWriter &Writer) const {
+ Header H;
+ H.Size = size();
+ H.Capacity = capacity();
+ if (auto EC = Writer.writeObject(H))
+ return EC;
+
+ if (auto EC = writeSparseBitVector(Writer, Present))
+ return EC;
+
+ if (auto EC = writeSparseBitVector(Writer, Deleted))
+ return EC;
+
+ for (const auto &Entry : *this) {
+ if (auto EC = Writer.writeInteger(Entry.first))
+ return EC;
+ if (auto EC = Writer.writeInteger(Entry.second))
+ return EC;
+ }
+ return Error::success();
+}
+
+void HashTable::clear() {
+ Buckets.resize(8);
+ Present.clear();
+ Deleted.clear();
+}
+
+uint32_t HashTable::capacity() const { return Buckets.size(); }
+
+uint32_t HashTable::size() const { return Present.count(); }
+
+HashTableIterator HashTable::begin() const { return HashTableIterator(*this); }
+
+HashTableIterator HashTable::end() const {
+ return HashTableIterator(*this, 0, true);
+}
+
+HashTableIterator HashTable::find(uint32_t K) {
+ uint32_t H = K % capacity();
+ uint32_t I = H;
+ Optional<uint32_t> FirstUnused;
+ do {
+ if (isPresent(I)) {
+ if (Buckets[I].first == K)
+ return HashTableIterator(*this, I, false);
+ } else {
+ if (!FirstUnused)
+ FirstUnused = I;
+ // Insertion occurs via linear probing from the slot hint, and will be
+ // inserted at the first empty / deleted location. Therefore, if we are
+ // probing and find a location that is neither present nor deleted, then
+ // nothing must have EVER been inserted at this location, and thus it is
+ // not possible for a matching value to occur later.
+ if (!isDeleted(I))
+ break;
+ }
+ I = (I + 1) % capacity();
+ } while (I != H);
+
+ // The only way FirstUnused would not be set is if every single entry in the
+ // table were Present. But this would violate the load factor constraints
+ // that we impose, so it should never happen.
+ assert(FirstUnused);
+ return HashTableIterator(*this, *FirstUnused, true);
+}
+
+void HashTable::set(uint32_t K, uint32_t V) {
+ auto Entry = find(K);
+ if (Entry != end()) {
+ assert(isPresent(Entry.index()));
+ assert(Buckets[Entry.index()].first == K);
+ // We're updating, no need to do anything special.
+ Buckets[Entry.index()].second = V;
+ return;
+ }
+
+ auto &B = Buckets[Entry.index()];
+ assert(!isPresent(Entry.index()));
+ assert(Entry.isEnd());
+ B.first = K;
+ B.second = V;
+ Present.set(Entry.index());
+ Deleted.reset(Entry.index());
+
+ grow();
+
+ assert(find(K) != end());
+}
+
+void HashTable::remove(uint32_t K) {
+ auto Iter = find(K);
+ // It wasn't here to begin with, just exit.
+ if (Iter == end())
+ return;
+
+ assert(Present.test(Iter.index()));
+ assert(!Deleted.test(Iter.index()));
+ Deleted.set(Iter.index());
+ Present.reset(Iter.index());
+}
+
+uint32_t HashTable::get(uint32_t K) {
+ auto I = find(K);
+ assert(I != end());
+ return (*I).second;
+}
+
+uint32_t HashTable::maxLoad(uint32_t capacity) { return capacity * 2 / 3 + 1; }
+
+void HashTable::grow() {
+ uint32_t S = size();
+ if (S < maxLoad(capacity()))
+ return;
+ assert(capacity() != UINT32_MAX && "Can't grow Hash table!");
+
+ uint32_t NewCapacity =
+ (capacity() <= INT32_MAX) ? capacity() * 2 : UINT32_MAX;
+
+ // Growing requires rebuilding the table and re-hashing every item. Make a
+ // copy with a larger capacity, insert everything into the copy, then swap
+ // it in.
+ HashTable NewMap(NewCapacity);
+ for (auto I : Present) {
+ NewMap.set(Buckets[I].first, Buckets[I].second);
+ }
+
+ Buckets.swap(NewMap.Buckets);
+ std::swap(Present, NewMap.Present);
+ std::swap(Deleted, NewMap.Deleted);
+ assert(capacity() == NewCapacity);
+ assert(size() == S);
+}
+
+Error HashTable::readSparseBitVector(BinaryStreamReader &Stream,
+ SparseBitVector<> &V) {
+ uint32_t NumWords;
+ if (auto EC = Stream.readInteger(NumWords))
+ return joinErrors(
+ std::move(EC),
+ make_error<RawError>(raw_error_code::corrupt_file,
+ "Expected hash table number of words"));
+
+ for (uint32_t I = 0; I != NumWords; ++I) {
+ uint32_t Word;
+ if (auto EC = Stream.readInteger(Word))
+ return joinErrors(std::move(EC),
+ make_error<RawError>(raw_error_code::corrupt_file,
+ "Expected hash table word"));
+ for (unsigned Idx = 0; Idx < 32; ++Idx)
+ if (Word & (1U << Idx))
+ V.set((I * 32) + Idx);
+ }
+ return Error::success();
+}
+
+Error HashTable::writeSparseBitVector(BinaryStreamWriter &Writer,
+ SparseBitVector<> &Vec) {
+ int ReqBits = Vec.find_last() + 1;
+ uint32_t NumWords = alignTo(ReqBits, sizeof(uint32_t)) / sizeof(uint32_t);
+ if (auto EC = Writer.writeInteger(NumWords))
+ return joinErrors(
+ std::move(EC),
+ make_error<RawError>(raw_error_code::corrupt_file,
+ "Could not write linear map number of words"));
+
+ uint32_t Idx = 0;
+ for (uint32_t I = 0; I != NumWords; ++I) {
+ uint32_t Word = 0;
+ for (uint32_t WordIdx = 0; WordIdx < 32; ++WordIdx, ++Idx) {
+ if (Vec.test(Idx))
+ Word |= (1 << WordIdx);
+ }
+ if (auto EC = Writer.writeInteger(Word))
+ return joinErrors(std::move(EC), make_error<RawError>(
+ raw_error_code::corrupt_file,
+ "Could not write linear map word"));
+ }
+ return Error::success();
+}
+
+HashTableIterator::HashTableIterator(const HashTable &Map, uint32_t Index,
+ bool IsEnd)
+ : Map(&Map), Index(Index), IsEnd(IsEnd) {}
+
+HashTableIterator::HashTableIterator(const HashTable &Map) : Map(&Map) {
+ int I = Map.Present.find_first();
+ if (I == -1) {
+ Index = 0;
+ IsEnd = true;
+ } else {
+ Index = static_cast<uint32_t>(I);
+ IsEnd = false;
+ }
+}
+
+HashTableIterator &HashTableIterator::operator=(const HashTableIterator &R) {
+ Map = R.Map;
+ return *this;
+}
+
+bool HashTableIterator::operator==(const HashTableIterator &R) const {
+ if (IsEnd && R.IsEnd)
+ return true;
+ if (IsEnd != R.IsEnd)
+ return false;
+
+ return (Map == R.Map) && (Index == R.Index);
+}
+
+const std::pair<uint32_t, uint32_t> &HashTableIterator::operator*() const {
+ assert(Map->Present.test(Index));
+ return Map->Buckets[Index];
+}
+
+HashTableIterator &HashTableIterator::operator++() {
+ while (Index < Map->Buckets.size()) {
+ ++Index;
+ if (Map->Present.test(Index))
+ return *this;
+ }
+
+ IsEnd = true;
+ return *this;
+}
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