Imported Upstream version 5.18.0.179

Former-commit-id: 67aa10e65b237e1c4537630979ee99ebe1374215

external/llvm/lib/Bitcode/Reader/BitReader.cpp

@@ -0,0 +1,134 @@
+//===-- BitReader.cpp -----------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm-c/BitReader.h"
+#include "llvm-c/Core.h"
+#include "llvm/Bitcode/BitcodeReader.h"
+#include "llvm/IR/LLVMContext.h"
+#include "llvm/IR/Module.h"
+#include "llvm/Support/MemoryBuffer.h"
+#include "llvm/Support/raw_ostream.h"
+#include <cstring>
+#include <string>
+
+using namespace llvm;
+
+/* Builds a module from the bitcode in the specified memory buffer, returning a
+   reference to the module via the OutModule parameter. Returns 0 on success.
+   Optionally returns a human-readable error message via OutMessage. */
+LLVMBool LLVMParseBitcode(LLVMMemoryBufferRef MemBuf, LLVMModuleRef *OutModule,
+                          char **OutMessage) {
+  return LLVMParseBitcodeInContext(LLVMGetGlobalContext(), MemBuf, OutModule,
+                                   OutMessage);
+}
+
+LLVMBool LLVMParseBitcode2(LLVMMemoryBufferRef MemBuf,
+                           LLVMModuleRef *OutModule) {
+  return LLVMParseBitcodeInContext2(LLVMGetGlobalContext(), MemBuf, OutModule);
+}
+
+LLVMBool LLVMParseBitcodeInContext(LLVMContextRef ContextRef,
+                                   LLVMMemoryBufferRef MemBuf,
+                                   LLVMModuleRef *OutModule,
+                                   char **OutMessage) {
+  MemoryBufferRef Buf = unwrap(MemBuf)->getMemBufferRef();
+  LLVMContext &Ctx = *unwrap(ContextRef);
+
+  Expected<std::unique_ptr<Module>> ModuleOrErr = parseBitcodeFile(Buf, Ctx);
+  if (Error Err = ModuleOrErr.takeError()) {
+    std::string Message;
+    handleAllErrors(std::move(Err), [&](ErrorInfoBase &EIB) {
+      Message = EIB.message();
+    });
+    if (OutMessage)
+      *OutMessage = strdup(Message.c_str());
+    *OutModule = wrap((Module *)nullptr);
+    return 1;
+  }
+
+  *OutModule = wrap(ModuleOrErr.get().release());
+  return 0;
+}
+
+LLVMBool LLVMParseBitcodeInContext2(LLVMContextRef ContextRef,
+                                    LLVMMemoryBufferRef MemBuf,
+                                    LLVMModuleRef *OutModule) {
+  MemoryBufferRef Buf = unwrap(MemBuf)->getMemBufferRef();
+  LLVMContext &Ctx = *unwrap(ContextRef);
+
+  ErrorOr<std::unique_ptr<Module>> ModuleOrErr =
+      expectedToErrorOrAndEmitErrors(Ctx, parseBitcodeFile(Buf, Ctx));
+  if (ModuleOrErr.getError()) {
+    *OutModule = wrap((Module *)nullptr);
+    return 1;
+  }
+
+  *OutModule = wrap(ModuleOrErr.get().release());
+  return 0;
+}
+
+/* Reads a module from the specified path, returning via the OutModule parameter
+   a module provider which performs lazy deserialization. Returns 0 on success.
+   Optionally returns a human-readable error message via OutMessage. */
+LLVMBool LLVMGetBitcodeModuleInContext(LLVMContextRef ContextRef,
+                                       LLVMMemoryBufferRef MemBuf,
+                                       LLVMModuleRef *OutM, char **OutMessage) {
+  LLVMContext &Ctx = *unwrap(ContextRef);
+  std::unique_ptr<MemoryBuffer> Owner(unwrap(MemBuf));
+  Expected<std::unique_ptr<Module>> ModuleOrErr =
+      getOwningLazyBitcodeModule(std::move(Owner), Ctx);
+  // Release the buffer if we didn't take ownership of it since we never owned
+  // it anyway.
+  (void)Owner.release();
+
+  if (Error Err = ModuleOrErr.takeError()) {
+    std::string Message;
+    handleAllErrors(std::move(Err), [&](ErrorInfoBase &EIB) {
+      Message = EIB.message();
+    });
+    if (OutMessage)
+      *OutMessage = strdup(Message.c_str());
+    *OutM = wrap((Module *)nullptr);
+    return 1;
+  }
+
+  *OutM = wrap(ModuleOrErr.get().release());
+
+  return 0;
+}
+
+LLVMBool LLVMGetBitcodeModuleInContext2(LLVMContextRef ContextRef,
+                                        LLVMMemoryBufferRef MemBuf,
+                                        LLVMModuleRef *OutM) {
+  LLVMContext &Ctx = *unwrap(ContextRef);
+  std::unique_ptr<MemoryBuffer> Owner(unwrap(MemBuf));
+
+  ErrorOr<std::unique_ptr<Module>> ModuleOrErr = expectedToErrorOrAndEmitErrors(
+      Ctx, getOwningLazyBitcodeModule(std::move(Owner), Ctx));
+  Owner.release();
+
+  if (ModuleOrErr.getError()) {
+    *OutM = wrap((Module *)nullptr);
+    return 1;
+  }
+
+  *OutM = wrap(ModuleOrErr.get().release());
+  return 0;
+}
+
+LLVMBool LLVMGetBitcodeModule(LLVMMemoryBufferRef MemBuf, LLVMModuleRef *OutM,
+                              char **OutMessage) {
+  return LLVMGetBitcodeModuleInContext(LLVMGetGlobalContext(), MemBuf, OutM,
+                                       OutMessage);
+}
+
+LLVMBool LLVMGetBitcodeModule2(LLVMMemoryBufferRef MemBuf,
+                               LLVMModuleRef *OutM) {
+  return LLVMGetBitcodeModuleInContext2(LLVMGetGlobalContext(), MemBuf, OutM);
+}

external/llvm/lib/Bitcode/Reader/BitcodeReader.cpp.REMOVED.git-id

@@ -0,0 +1 @@
+945ac451536862033d0336f38be662d9657a3e72

external/llvm/lib/Bitcode/Reader/BitstreamReader.cpp

@@ -0,0 +1,390 @@
+//===- BitstreamReader.cpp - BitstreamReader implementation ---------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Bitcode/BitstreamReader.h"
+#include "llvm/ADT/StringRef.h"
+#include <cassert>
+#include <string>
+
+using namespace llvm;
+
+//===----------------------------------------------------------------------===//
+//  BitstreamCursor implementation
+//===----------------------------------------------------------------------===//
+
+/// EnterSubBlock - Having read the ENTER_SUBBLOCK abbrevid, enter
+/// the block, and return true if the block has an error.
+bool BitstreamCursor::EnterSubBlock(unsigned BlockID, unsigned *NumWordsP) {
+  // Save the current block's state on BlockScope.
+  BlockScope.push_back(Block(CurCodeSize));
+  BlockScope.back().PrevAbbrevs.swap(CurAbbrevs);
+
+  // Add the abbrevs specific to this block to the CurAbbrevs list.
+  if (BlockInfo) {
+    if (const BitstreamBlockInfo::BlockInfo *Info =
+            BlockInfo->getBlockInfo(BlockID)) {
+      CurAbbrevs.insert(CurAbbrevs.end(), Info->Abbrevs.begin(),
+                        Info->Abbrevs.end());
+    }
+  }
+
+  // Get the codesize of this block.
+  CurCodeSize = ReadVBR(bitc::CodeLenWidth);
+  // We can't read more than MaxChunkSize at a time
+  if (CurCodeSize > MaxChunkSize)
+    return true;
+
+  SkipToFourByteBoundary();
+  unsigned NumWords = Read(bitc::BlockSizeWidth);
+  if (NumWordsP) *NumWordsP = NumWords;
+
+  // Validate that this block is sane.
+  return CurCodeSize == 0 || AtEndOfStream();
+}
+
+static uint64_t readAbbreviatedField(BitstreamCursor &Cursor,
+                                     const BitCodeAbbrevOp &Op) {
+  assert(!Op.isLiteral() && "Not to be used with literals!");
+
+  // Decode the value as we are commanded.
+  switch (Op.getEncoding()) {
+  case BitCodeAbbrevOp::Array:
+  case BitCodeAbbrevOp::Blob:
+    llvm_unreachable("Should not reach here");
+  case BitCodeAbbrevOp::Fixed:
+    assert((unsigned)Op.getEncodingData() <= Cursor.MaxChunkSize);
+    return Cursor.Read((unsigned)Op.getEncodingData());
+  case BitCodeAbbrevOp::VBR:
+    assert((unsigned)Op.getEncodingData() <= Cursor.MaxChunkSize);
+    return Cursor.ReadVBR64((unsigned)Op.getEncodingData());
+  case BitCodeAbbrevOp::Char6:
+    return BitCodeAbbrevOp::DecodeChar6(Cursor.Read(6));
+  }
+  llvm_unreachable("invalid abbreviation encoding");
+}
+
+static void skipAbbreviatedField(BitstreamCursor &Cursor,
+                                 const BitCodeAbbrevOp &Op) {
+  assert(!Op.isLiteral() && "Not to be used with literals!");
+
+  // Decode the value as we are commanded.
+  switch (Op.getEncoding()) {
+  case BitCodeAbbrevOp::Array:
+  case BitCodeAbbrevOp::Blob:
+    llvm_unreachable("Should not reach here");
+  case BitCodeAbbrevOp::Fixed:
+    assert((unsigned)Op.getEncodingData() <= Cursor.MaxChunkSize);
+    Cursor.Read((unsigned)Op.getEncodingData());
+    break;
+  case BitCodeAbbrevOp::VBR:
+    assert((unsigned)Op.getEncodingData() <= Cursor.MaxChunkSize);
+    Cursor.ReadVBR64((unsigned)Op.getEncodingData());
+    break;
+  case BitCodeAbbrevOp::Char6:
+    Cursor.Read(6);
+    break;
+  }
+}
+
+/// skipRecord - Read the current record and discard it.
+unsigned BitstreamCursor::skipRecord(unsigned AbbrevID) {
+  // Skip unabbreviated records by reading past their entries.
+  if (AbbrevID == bitc::UNABBREV_RECORD) {
+    unsigned Code = ReadVBR(6);
+    unsigned NumElts = ReadVBR(6);
+    for (unsigned i = 0; i != NumElts; ++i)
+      (void)ReadVBR64(6);
+    return Code;
+  }
+
+  const BitCodeAbbrev *Abbv = getAbbrev(AbbrevID);
+  const BitCodeAbbrevOp &CodeOp = Abbv->getOperandInfo(0);
+  unsigned Code;
+  if (CodeOp.isLiteral())
+    Code = CodeOp.getLiteralValue();
+  else {
+    if (CodeOp.getEncoding() == BitCodeAbbrevOp::Array ||
+        CodeOp.getEncoding() == BitCodeAbbrevOp::Blob)
+      report_fatal_error("Abbreviation starts with an Array or a Blob");
+    Code = readAbbreviatedField(*this, CodeOp);
+  }
+
+  for (unsigned i = 1, e = Abbv->getNumOperandInfos(); i < e; ++i) {
+    const BitCodeAbbrevOp &Op = Abbv->getOperandInfo(i);
+    if (Op.isLiteral())
+      continue;
+
+    if (Op.getEncoding() != BitCodeAbbrevOp::Array &&
+        Op.getEncoding() != BitCodeAbbrevOp::Blob) {
+      skipAbbreviatedField(*this, Op);
+      continue;
+    }
+
+    if (Op.getEncoding() == BitCodeAbbrevOp::Array) {
+      // Array case.  Read the number of elements as a vbr6.
+      unsigned NumElts = ReadVBR(6);
+
+      // Get the element encoding.
+      assert(i+2 == e && "array op not second to last?");
+      const BitCodeAbbrevOp &EltEnc = Abbv->getOperandInfo(++i);
+
+      // Read all the elements.
+      // Decode the value as we are commanded.
+      switch (EltEnc.getEncoding()) {
+      default:
+        report_fatal_error("Array element type can't be an Array or a Blob");
+      case BitCodeAbbrevOp::Fixed:
+        assert((unsigned)EltEnc.getEncodingData() <= MaxChunkSize);
+        JumpToBit(GetCurrentBitNo() + NumElts * EltEnc.getEncodingData());
+        break;
+      case BitCodeAbbrevOp::VBR:
+        assert((unsigned)EltEnc.getEncodingData() <= MaxChunkSize);
+        for (; NumElts; --NumElts)
+          ReadVBR64((unsigned)EltEnc.getEncodingData());
+        break;
+      case BitCodeAbbrevOp::Char6:
+        JumpToBit(GetCurrentBitNo() + NumElts * 6);
+        break;
+      }
+      continue;
+    }
+
+    assert(Op.getEncoding() == BitCodeAbbrevOp::Blob);
+    // Blob case.  Read the number of bytes as a vbr6.
+    unsigned NumElts = ReadVBR(6);
+    SkipToFourByteBoundary();  // 32-bit alignment
+
+    // Figure out where the end of this blob will be including tail padding.
+    size_t NewEnd = GetCurrentBitNo()+((NumElts+3)&~3)*8;
+
+    // If this would read off the end of the bitcode file, just set the
+    // record to empty and return.
+    if (!canSkipToPos(NewEnd/8)) {
+      skipToEnd();
+      break;
+    }
+
+    // Skip over the blob.
+    JumpToBit(NewEnd);
+  }
+  return Code;
+}
+
+unsigned BitstreamCursor::readRecord(unsigned AbbrevID,
+                                     SmallVectorImpl<uint64_t> &Vals,
+                                     StringRef *Blob) {
+  if (AbbrevID == bitc::UNABBREV_RECORD) {
+    unsigned Code = ReadVBR(6);
+    unsigned NumElts = ReadVBR(6);
+    for (unsigned i = 0; i != NumElts; ++i)
+      Vals.push_back(ReadVBR64(6));
+    return Code;
+  }
+
+  const BitCodeAbbrev *Abbv = getAbbrev(AbbrevID);
+
+  // Read the record code first.
+  assert(Abbv->getNumOperandInfos() != 0 && "no record code in abbreviation?");
+  const BitCodeAbbrevOp &CodeOp = Abbv->getOperandInfo(0);
+  unsigned Code;
+  if (CodeOp.isLiteral())
+    Code = CodeOp.getLiteralValue();
+  else {
+    if (CodeOp.getEncoding() == BitCodeAbbrevOp::Array ||
+        CodeOp.getEncoding() == BitCodeAbbrevOp::Blob)
+      report_fatal_error("Abbreviation starts with an Array or a Blob");
+    Code = readAbbreviatedField(*this, CodeOp);
+  }
+
+  for (unsigned i = 1, e = Abbv->getNumOperandInfos(); i != e; ++i) {
+    const BitCodeAbbrevOp &Op = Abbv->getOperandInfo(i);
+    if (Op.isLiteral()) {
+      Vals.push_back(Op.getLiteralValue());
+      continue;
+    }
+
+    if (Op.getEncoding() != BitCodeAbbrevOp::Array &&
+        Op.getEncoding() != BitCodeAbbrevOp::Blob) {
+      Vals.push_back(readAbbreviatedField(*this, Op));
+      continue;
+    }
+
+    if (Op.getEncoding() == BitCodeAbbrevOp::Array) {
+      // Array case.  Read the number of elements as a vbr6.
+      unsigned NumElts = ReadVBR(6);
+
+      // Get the element encoding.
+      if (i + 2 != e)
+        report_fatal_error("Array op not second to last");
+      const BitCodeAbbrevOp &EltEnc = Abbv->getOperandInfo(++i);
+      if (!EltEnc.isEncoding())
+        report_fatal_error(
+            "Array element type has to be an encoding of a type");
+
+      // Read all the elements.
+      switch (EltEnc.getEncoding()) {
+      default:
+        report_fatal_error("Array element type can't be an Array or a Blob");
+      case BitCodeAbbrevOp::Fixed:
+        for (; NumElts; --NumElts)
+          Vals.push_back(Read((unsigned)EltEnc.getEncodingData()));
+        break;
+      case BitCodeAbbrevOp::VBR:
+        for (; NumElts; --NumElts)
+          Vals.push_back(ReadVBR64((unsigned)EltEnc.getEncodingData()));
+        break;
+      case BitCodeAbbrevOp::Char6:
+        for (; NumElts; --NumElts)
+          Vals.push_back(BitCodeAbbrevOp::DecodeChar6(Read(6)));
+      }
+      continue;
+    }
+
+    assert(Op.getEncoding() == BitCodeAbbrevOp::Blob);
+    // Blob case.  Read the number of bytes as a vbr6.
+    unsigned NumElts = ReadVBR(6);
+    SkipToFourByteBoundary();  // 32-bit alignment
+
+    // Figure out where the end of this blob will be including tail padding.
+    size_t CurBitPos = GetCurrentBitNo();
+    size_t NewEnd = CurBitPos+((NumElts+3)&~3)*8;
+
+    // If this would read off the end of the bitcode file, just set the
+    // record to empty and return.
+    if (!canSkipToPos(NewEnd/8)) {
+      Vals.append(NumElts, 0);
+      skipToEnd();
+      break;
+    }
+
+    // Otherwise, inform the streamer that we need these bytes in memory.  Skip
+    // over tail padding first, in case jumping to NewEnd invalidates the Blob
+    // pointer.
+    JumpToBit(NewEnd);
+    const char *Ptr = (const char *)getPointerToBit(CurBitPos, NumElts);
+
+    // If we can return a reference to the data, do so to avoid copying it.
+    if (Blob) {
+      *Blob = StringRef(Ptr, NumElts);
+    } else {
+      // Otherwise, unpack into Vals with zero extension.
+      for (; NumElts; --NumElts)
+        Vals.push_back((unsigned char)*Ptr++);
+    }
+  }
+
+  return Code;
+}
+
+void BitstreamCursor::ReadAbbrevRecord() {
+  auto Abbv = std::make_shared<BitCodeAbbrev>();
+  unsigned NumOpInfo = ReadVBR(5);
+  for (unsigned i = 0; i != NumOpInfo; ++i) {
+    bool IsLiteral = Read(1);
+    if (IsLiteral) {
+      Abbv->Add(BitCodeAbbrevOp(ReadVBR64(8)));
+      continue;
+    }
+
+    BitCodeAbbrevOp::Encoding E = (BitCodeAbbrevOp::Encoding)Read(3);
+    if (BitCodeAbbrevOp::hasEncodingData(E)) {
+      uint64_t Data = ReadVBR64(5);
+
+      // As a special case, handle fixed(0) (i.e., a fixed field with zero bits)
+      // and vbr(0) as a literal zero.  This is decoded the same way, and avoids
+      // a slow path in Read() to have to handle reading zero bits.
+      if ((E == BitCodeAbbrevOp::Fixed || E == BitCodeAbbrevOp::VBR) &&
+          Data == 0) {
+        Abbv->Add(BitCodeAbbrevOp(0));
+        continue;
+      }
+
+      if ((E == BitCodeAbbrevOp::Fixed || E == BitCodeAbbrevOp::VBR) &&
+          Data > MaxChunkSize)
+        report_fatal_error(
+            "Fixed or VBR abbrev record with size > MaxChunkData");
+
+      Abbv->Add(BitCodeAbbrevOp(E, Data));
+    } else
+      Abbv->Add(BitCodeAbbrevOp(E));
+  }
+
+  if (Abbv->getNumOperandInfos() == 0)
+    report_fatal_error("Abbrev record with no operands");
+  CurAbbrevs.push_back(std::move(Abbv));
+}
+
+Optional<BitstreamBlockInfo>
+BitstreamCursor::ReadBlockInfoBlock(bool ReadBlockInfoNames) {
+  if (EnterSubBlock(bitc::BLOCKINFO_BLOCK_ID)) return None;
+
+  BitstreamBlockInfo NewBlockInfo;
+
+  SmallVector<uint64_t, 64> Record;
+  BitstreamBlockInfo::BlockInfo *CurBlockInfo = nullptr;
+
+  // Read all the records for this module.
+  while (true) {
+    BitstreamEntry Entry = advanceSkippingSubblocks(AF_DontAutoprocessAbbrevs);
+
+    switch (Entry.Kind) {
+    case llvm::BitstreamEntry::SubBlock: // Handled for us already.
+    case llvm::BitstreamEntry::Error:
+      return None;
+    case llvm::BitstreamEntry::EndBlock:
+      return std::move(NewBlockInfo);
+    case llvm::BitstreamEntry::Record:
+      // The interesting case.
+      break;
+    }
+
+    // Read abbrev records, associate them with CurBID.
+    if (Entry.ID == bitc::DEFINE_ABBREV) {
+      if (!CurBlockInfo) return None;
+      ReadAbbrevRecord();
+
+      // ReadAbbrevRecord installs the abbrev in CurAbbrevs.  Move it to the
+      // appropriate BlockInfo.
+      CurBlockInfo->Abbrevs.push_back(std::move(CurAbbrevs.back()));
+      CurAbbrevs.pop_back();
+      continue;
+    }
+
+    // Read a record.
+    Record.clear();
+    switch (readRecord(Entry.ID, Record)) {
+      default: break;  // Default behavior, ignore unknown content.
+      case bitc::BLOCKINFO_CODE_SETBID:
+        if (Record.size() < 1) return None;
+        CurBlockInfo = &NewBlockInfo.getOrCreateBlockInfo((unsigned)Record[0]);
+        break;
+      case bitc::BLOCKINFO_CODE_BLOCKNAME: {
+        if (!CurBlockInfo) return None;
+        if (!ReadBlockInfoNames)
+          break; // Ignore name.
+        std::string Name;
+        for (unsigned i = 0, e = Record.size(); i != e; ++i)
+          Name += (char)Record[i];
+        CurBlockInfo->Name = Name;
+        break;
+      }
+      case bitc::BLOCKINFO_CODE_SETRECORDNAME: {
+        if (!CurBlockInfo) return None;
+        if (!ReadBlockInfoNames)
+          break; // Ignore name.
+        std::string Name;
+        for (unsigned i = 1, e = Record.size(); i != e; ++i)
+          Name += (char)Record[i];
+        CurBlockInfo->RecordNames.push_back(std::make_pair((unsigned)Record[0],
+                                                           Name));
+        break;
+      }
+    }
+  }
+}

external/llvm/lib/Bitcode/Reader/CMakeLists.txt

@@ -0,0 +1,13 @@
+add_llvm_library(LLVMBitReader
+  BitReader.cpp
+  BitcodeReader.cpp
+  BitstreamReader.cpp
+  MetadataLoader.cpp
+  ValueList.cpp
+
+  ADDITIONAL_HEADER_DIRS
+  ${LLVM_MAIN_INCLUDE_DIR}/llvm/Bitcode
+
+  DEPENDS
+  intrinsics_gen
+  )

external/llvm/lib/Bitcode/Reader/LLVMBuild.txt

@@ -0,0 +1,22 @@
+;===- ./lib/Bitcode/Reader/LLVMBuild.txt -----------------------*- Conf -*--===;
+;
+;                     The LLVM Compiler Infrastructure
+;
+; This file is distributed under the University of Illinois Open Source
+; License. See LICENSE.TXT for details.
+;
+;===------------------------------------------------------------------------===;
+;
+; This is an LLVMBuild description file for the components in this subdirectory.
+;
+; For more information on the LLVMBuild system, please see:
+;
+;   http://llvm.org/docs/LLVMBuild.html
+;
+;===------------------------------------------------------------------------===;
+
+[component_0]
+type = Library
+name = BitReader
+parent = Bitcode
+required_libraries = Core Support

external/llvm/lib/Bitcode/Reader/MetadataLoader.h

@@ -0,0 +1,88 @@
+//===-- Bitcode/Reader/MetadataLoader.h - Load Metadatas -------*- C++ -*-====//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This class handles loading Metadatas.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIB_BITCODE_READER_METADATALOADER_H
+#define LLVM_LIB_BITCODE_READER_METADATALOADER_H
+
+#include "llvm/ADT/SmallVector.h"
+#include "llvm/Support/Error.h"
+
+#include <functional>
+#include <memory>
+
+namespace llvm {
+class BitcodeReaderValueList;
+class BitstreamCursor;
+class DISubprogram;
+class Error;
+class Function;
+class Instruction;
+class Metadata;
+class MDNode;
+class Module;
+class Type;
+
+/// Helper class that handles loading Metadatas and keeping them available.
+class MetadataLoader {
+  class MetadataLoaderImpl;
+  std::unique_ptr<MetadataLoaderImpl> Pimpl;
+  Error parseMetadata(bool ModuleLevel);
+
+public:
+  ~MetadataLoader();
+  MetadataLoader(BitstreamCursor &Stream, Module &TheModule,
+                 BitcodeReaderValueList &ValueList, bool IsImporting,
+                 std::function<Type *(unsigned)> getTypeByID);
+  MetadataLoader &operator=(MetadataLoader &&);
+  MetadataLoader(MetadataLoader &&);
+
+  // Parse a module metadata block
+  Error parseModuleMetadata() { return parseMetadata(true); }
+
+  // Parse a function metadata block
+  Error parseFunctionMetadata() { return parseMetadata(false); }
+
+  /// Set the mode to strip TBAA metadata on load.
+  void setStripTBAA(bool StripTBAA = true);
+
+  /// Return true if the Loader is stripping TBAA metadata.
+  bool isStrippingTBAA();
+
+  // Return true there are remaining unresolved forward references.
+  bool hasFwdRefs() const;
+
+  /// Return the given metadata, creating a replaceable forward reference if
+  /// necessary.
+  Metadata *getMetadataFwdRefOrLoad(unsigned Idx);
+
+  MDNode *getMDNodeFwdRefOrNull(unsigned Idx);
+
+  /// Return the DISubprogra metadata for a Function if any, null otherwise.
+  DISubprogram *lookupSubprogramForFunction(Function *F);
+
+  /// Parse a `METADATA_ATTACHMENT` block for a function.
+  Error parseMetadataAttachment(
+      Function &F, const SmallVectorImpl<Instruction *> &InstructionList);
+
+  /// Parse a `METADATA_KIND` block for the current module.
+  Error parseMetadataKinds();
+
+  unsigned size() const;
+  void shrinkTo(unsigned N);
+
+  /// Perform bitcode upgrades on llvm.dbg.* calls.
+  void upgradeDebugIntrinsics(Function &F);
+};
+}
+
+#endif // LLVM_LIB_BITCODE_READER_METADATALOADER_H

external/llvm/lib/Bitcode/Reader/ValueList.cpp

@@ -0,0 +1,216 @@
+//===- ValueList.cpp - Internal BitcodeReader implementation --------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "ValueList.h"
+#include "llvm/ADT/SmallVector.h"
+#include "llvm/IR/Argument.h"
+#include "llvm/IR/Constant.h"
+#include "llvm/IR/Constants.h"
+#include "llvm/IR/GlobalValue.h"
+#include "llvm/IR/Instruction.h"
+#include "llvm/IR/Type.h"
+#include "llvm/IR/User.h"
+#include "llvm/IR/Value.h"
+#include "llvm/IR/ValueHandle.h"
+#include "llvm/Support/Casting.h"
+#include "llvm/Support/ErrorHandling.h"
+#include <algorithm>
+#include <cassert>
+#include <cstddef>
+#include <limits>
+#include <utility>
+
+using namespace llvm;
+
+namespace llvm {
+
+namespace {
+
+/// \brief A class for maintaining the slot number definition
+/// as a placeholder for the actual definition for forward constants defs.
+class ConstantPlaceHolder : public ConstantExpr {
+public:
+  explicit ConstantPlaceHolder(Type *Ty, LLVMContext &Context)
+      : ConstantExpr(Ty, Instruction::UserOp1, &Op<0>(), 1) {
+    Op<0>() = UndefValue::get(Type::getInt32Ty(Context));
+  }
+
+  ConstantPlaceHolder &operator=(const ConstantPlaceHolder &) = delete;
+
+  // allocate space for exactly one operand
+  void *operator new(size_t s) { return User::operator new(s, 1); }
+
+  /// \brief Methods to support type inquiry through isa, cast, and dyn_cast.
+  static bool classof(const Value *V) {
+    return isa<ConstantExpr>(V) &&
+           cast<ConstantExpr>(V)->getOpcode() == Instruction::UserOp1;
+  }
+
+  /// Provide fast operand accessors
+  DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Value);
+};
+
+} // end anonymous namespace
+
+// FIXME: can we inherit this from ConstantExpr?
+template <>
+struct OperandTraits<ConstantPlaceHolder>
+    : public FixedNumOperandTraits<ConstantPlaceHolder, 1> {};
+DEFINE_TRANSPARENT_OPERAND_ACCESSORS(ConstantPlaceHolder, Value)
+
+} // end namespace llvm
+
+void BitcodeReaderValueList::assignValue(Value *V, unsigned Idx) {
+  if (Idx == size()) {
+    push_back(V);
+    return;
+  }
+
+  if (Idx >= size())
+    resize(Idx + 1);
+
+  WeakTrackingVH &OldV = ValuePtrs[Idx];
+  if (!OldV) {
+    OldV = V;
+    return;
+  }
+
+  // Handle constants and non-constants (e.g. instrs) differently for
+  // efficiency.
+  if (Constant *PHC = dyn_cast<Constant>(&*OldV)) {
+    ResolveConstants.push_back(std::make_pair(PHC, Idx));
+    OldV = V;
+  } else {
+    // If there was a forward reference to this value, replace it.
+    Value *PrevVal = OldV;
+    OldV->replaceAllUsesWith(V);
+    PrevVal->deleteValue();
+  }
+}
+
+Constant *BitcodeReaderValueList::getConstantFwdRef(unsigned Idx, Type *Ty) {
+  if (Idx >= size())
+    resize(Idx + 1);
+
+  if (Value *V = ValuePtrs[Idx]) {
+    if (Ty != V->getType())
+      report_fatal_error("Type mismatch in constant table!");
+    return cast<Constant>(V);
+  }
+
+  // Create and return a placeholder, which will later be RAUW'd.
+  Constant *C = new ConstantPlaceHolder(Ty, Context);
+  ValuePtrs[Idx] = C;
+  return C;
+}
+
+Value *BitcodeReaderValueList::getValueFwdRef(unsigned Idx, Type *Ty) {
+  // Bail out for a clearly invalid value. This would make us call resize(0)
+  if (Idx == std::numeric_limits<unsigned>::max())
+    return nullptr;
+
+  if (Idx >= size())
+    resize(Idx + 1);
+
+  if (Value *V = ValuePtrs[Idx]) {
+    // If the types don't match, it's invalid.
+    if (Ty && Ty != V->getType())
+      return nullptr;
+    return V;
+  }
+
+  // No type specified, must be invalid reference.
+  if (!Ty)
+    return nullptr;
+
+  // Create and return a placeholder, which will later be RAUW'd.
+  Value *V = new Argument(Ty);
+  ValuePtrs[Idx] = V;
+  return V;
+}
+
+/// Once all constants are read, this method bulk resolves any forward
+/// references.  The idea behind this is that we sometimes get constants (such
+/// as large arrays) which reference *many* forward ref constants.  Replacing
+/// each of these causes a lot of thrashing when building/reuniquing the
+/// constant.  Instead of doing this, we look at all the uses and rewrite all
+/// the place holders at once for any constant that uses a placeholder.
+void BitcodeReaderValueList::resolveConstantForwardRefs() {
+  // Sort the values by-pointer so that they are efficient to look up with a
+  // binary search.
+  std::sort(ResolveConstants.begin(), ResolveConstants.end());
+
+  SmallVector<Constant *, 64> NewOps;
+
+  while (!ResolveConstants.empty()) {
+    Value *RealVal = operator[](ResolveConstants.back().second);
+    Constant *Placeholder = ResolveConstants.back().first;
+    ResolveConstants.pop_back();
+
+    // Loop over all users of the placeholder, updating them to reference the
+    // new value.  If they reference more than one placeholder, update them all
+    // at once.
+    while (!Placeholder->use_empty()) {
+      auto UI = Placeholder->user_begin();
+      User *U = *UI;
+
+      // If the using object isn't uniqued, just update the operands.  This
+      // handles instructions and initializers for global variables.
+      if (!isa<Constant>(U) || isa<GlobalValue>(U)) {
+        UI.getUse().set(RealVal);
+        continue;
+      }
+
+      // Otherwise, we have a constant that uses the placeholder.  Replace that
+      // constant with a new constant that has *all* placeholder uses updated.
+      Constant *UserC = cast<Constant>(U);
+      for (User::op_iterator I = UserC->op_begin(), E = UserC->op_end(); I != E;
+           ++I) {
+        Value *NewOp;
+        if (!isa<ConstantPlaceHolder>(*I)) {
+          // Not a placeholder reference.
+          NewOp = *I;
+        } else if (*I == Placeholder) {
+          // Common case is that it just references this one placeholder.
+          NewOp = RealVal;
+        } else {
+          // Otherwise, look up the placeholder in ResolveConstants.
+          ResolveConstantsTy::iterator It = std::lower_bound(
+              ResolveConstants.begin(), ResolveConstants.end(),
+              std::pair<Constant *, unsigned>(cast<Constant>(*I), 0));
+          assert(It != ResolveConstants.end() && It->first == *I);
+          NewOp = operator[](It->second);
+        }
+
+        NewOps.push_back(cast<Constant>(NewOp));
+      }
+
+      // Make the new constant.
+      Constant *NewC;
+      if (ConstantArray *UserCA = dyn_cast<ConstantArray>(UserC)) {
+        NewC = ConstantArray::get(UserCA->getType(), NewOps);
+      } else if (ConstantStruct *UserCS = dyn_cast<ConstantStruct>(UserC)) {
+        NewC = ConstantStruct::get(UserCS->getType(), NewOps);
+      } else if (isa<ConstantVector>(UserC)) {
+        NewC = ConstantVector::get(NewOps);
+      } else {
+        assert(isa<ConstantExpr>(UserC) && "Must be a ConstantExpr.");
+        NewC = cast<ConstantExpr>(UserC)->getWithOperands(NewOps);
+      }
+
+      UserC->replaceAllUsesWith(NewC);
+      UserC->destroyConstant();
+      NewOps.clear();
+    }
+
+    // Update all ValueHandles, they should be the only users at this point.
+    Placeholder->replaceAllUsesWith(RealVal);
+    Placeholder->deleteValue();
+  }
+}

external/llvm/lib/Bitcode/Reader/ValueList.h

@@ -0,0 +1,86 @@
+//===-- Bitcode/Reader/ValueList.h - Number values --------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This class gives values and types Unique ID's.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIB_BITCODE_READER_VALUELIST_H
+#define LLVM_LIB_BITCODE_READER_VALUELIST_H
+
+#include "llvm/IR/ValueHandle.h"
+#include <cassert>
+#include <utility>
+#include <vector>
+
+namespace llvm {
+
+class Constant;
+class LLVMContext;
+class Type;
+class Value;
+
+class BitcodeReaderValueList {
+  std::vector<WeakTrackingVH> ValuePtrs;
+
+  /// As we resolve forward-referenced constants, we add information about them
+  /// to this vector.  This allows us to resolve them in bulk instead of
+  /// resolving each reference at a time.  See the code in
+  /// ResolveConstantForwardRefs for more information about this.
+  ///
+  /// The key of this vector is the placeholder constant, the value is the slot
+  /// number that holds the resolved value.
+  using ResolveConstantsTy = std::vector<std::pair<Constant *, unsigned>>;
+  ResolveConstantsTy ResolveConstants;
+  LLVMContext &Context;
+
+public:
+  BitcodeReaderValueList(LLVMContext &C) : Context(C) {}
+
+  ~BitcodeReaderValueList() {
+    assert(ResolveConstants.empty() && "Constants not resolved?");
+  }
+
+  // vector compatibility methods
+  unsigned size() const { return ValuePtrs.size(); }
+  void resize(unsigned N) { ValuePtrs.resize(N); }
+  void push_back(Value *V) { ValuePtrs.emplace_back(V); }
+
+  void clear() {
+    assert(ResolveConstants.empty() && "Constants not resolved?");
+    ValuePtrs.clear();
+  }
+
+  Value *operator[](unsigned i) const {
+    assert(i < ValuePtrs.size());
+    return ValuePtrs[i];
+  }
+
+  Value *back() const { return ValuePtrs.back(); }
+  void pop_back() { ValuePtrs.pop_back(); }
+  bool empty() const { return ValuePtrs.empty(); }
+
+  void shrinkTo(unsigned N) {
+    assert(N <= size() && "Invalid shrinkTo request!");
+    ValuePtrs.resize(N);
+  }
+
+  Constant *getConstantFwdRef(unsigned Idx, Type *Ty);
+  Value *getValueFwdRef(unsigned Idx, Type *Ty);
+
+  void assignValue(Value *V, unsigned Idx);
+
+  /// Once all constants are read, this method bulk resolves any forward
+  /// references.
+  void resolveConstantForwardRefs();
+};
+
+} // end namespace llvm
+
+#endif // LLVM_LIB_BITCODE_READER_VALUELIST_H