// BitstreamCursor implementation
//===----------------------------------------------------------------------===//
-void BitstreamCursor::operator=(const BitstreamCursor &RHS) {
- freeState();
-
- BitStream = RHS.BitStream;
- NextChar = RHS.NextChar;
- CurWord = RHS.CurWord;
- BitsInCurWord = RHS.BitsInCurWord;
- CurCodeSize = RHS.CurCodeSize;
-
- // Copy abbreviations, and bump ref counts.
- CurAbbrevs = RHS.CurAbbrevs;
- for (unsigned i = 0, e = static_cast<unsigned>(CurAbbrevs.size());
- i != e; ++i)
- CurAbbrevs[i]->addRef();
-
- // Copy block scope and bump ref counts.
- BlockScope = RHS.BlockScope;
- for (unsigned S = 0, e = static_cast<unsigned>(BlockScope.size());
- S != e; ++S) {
- std::vector<BitCodeAbbrev*> &Abbrevs = BlockScope[S].PrevAbbrevs;
- for (unsigned i = 0, e = static_cast<unsigned>(Abbrevs.size());
- i != e; ++i)
- Abbrevs[i]->addRef();
- }
-}
-
void BitstreamCursor::freeState() {
// Free all the Abbrevs.
- for (unsigned i = 0, e = static_cast<unsigned>(CurAbbrevs.size());
- i != e; ++i)
- CurAbbrevs[i]->dropRef();
CurAbbrevs.clear();
-
+
// Free all the Abbrevs in the block scope.
- for (unsigned S = 0, e = static_cast<unsigned>(BlockScope.size());
- S != e; ++S) {
- std::vector<BitCodeAbbrev*> &Abbrevs = BlockScope[S].PrevAbbrevs;
- for (unsigned i = 0, e = static_cast<unsigned>(Abbrevs.size());
- i != e; ++i)
- Abbrevs[i]->dropRef();
- }
BlockScope.clear();
}
// 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 (const BitstreamReader::BlockInfo *Info =
BitStream->getBlockInfo(BlockID)) {
- for (unsigned i = 0, e = static_cast<unsigned>(Info->Abbrevs.size());
- i != e; ++i) {
- CurAbbrevs.push_back(Info->Abbrevs[i]);
- CurAbbrevs.back()->addRef();
- }
+ CurAbbrevs.insert(CurAbbrevs.end(), Info->Abbrevs.begin(),
+ Info->Abbrevs.end());
}
-
+
// Get the codesize of this block.
CurCodeSize = ReadVBR(bitc::CodeLenWidth);
- SkipToWord();
+ // 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.
- if (CurCodeSize == 0 || AtEndOfStream())
- return true;
-
- return false;
+ 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.
+void BitstreamCursor::skipRecord(unsigned AbbrevID) {
+ // Skip unabbreviated records by reading past their entries.
+ if (AbbrevID == bitc::UNABBREV_RECORD) {
+ unsigned Code = ReadVBR(6);
+ (void)Code;
+ unsigned NumElts = ReadVBR(6);
+ for (unsigned i = 0; i != NumElts; ++i)
+ (void)ReadVBR64(6);
+ return;
+ }
+
+ const BitCodeAbbrev *Abbv = getAbbrev(AbbrevID);
+
+ for (unsigned i = 0, 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;
+ }
-unsigned BitstreamCursor::ReadRecord(unsigned AbbrevID,
+ 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.
+ for (; NumElts; --NumElts)
+ skipAbbreviatedField(*this, EltEnc);
+ 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)) {
+ NextChar = BitStream->getBitcodeBytes().getExtent();
+ break;
+ }
+
+ // Skip over the blob.
+ JumpToBit(NewEnd);
+ }
+}
+
+unsigned BitstreamCursor::readRecord(unsigned AbbrevID,
SmallVectorImpl<uint64_t> &Vals,
- const char **BlobStart, unsigned *BlobLen){
+ StringRef *Blob) {
if (AbbrevID == bitc::UNABBREV_RECORD) {
unsigned Code = ReadVBR(6);
unsigned NumElts = ReadVBR(6);
Vals.push_back(ReadVBR64(6));
return Code;
}
-
+
const BitCodeAbbrev *Abbv = getAbbrev(AbbrevID);
-
- for (unsigned i = 0, e = Abbv->getNumOperandInfos(); i != e; ++i) {
+
+ // 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()) {
- ReadAbbreviatedLiteral(Op, Vals);
+ Vals.push_back(Op.getLiteralValue());
continue;
}
-
+
if (Op.getEncoding() != BitCodeAbbrevOp::Array &&
Op.getEncoding() != BitCodeAbbrevOp::Blob) {
- ReadAbbreviatedField(Op, Vals);
+ 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.
- assert(i+2 == e && "array op not second to last?");
+ 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");
+ if (EltEnc.getEncoding() == BitCodeAbbrevOp::Array ||
+ EltEnc.getEncoding() == BitCodeAbbrevOp::Blob)
+ report_fatal_error("Array element type can't be an Array or a Blob");
+
// Read all the elements.
for (; NumElts; --NumElts)
- ReadAbbreviatedField(EltEnc, Vals);
+ Vals.push_back(readAbbreviatedField(*this, EltEnc));
continue;
}
-
+
assert(Op.getEncoding() == BitCodeAbbrevOp::Blob);
// Blob case. Read the number of bytes as a vbr6.
unsigned NumElts = ReadVBR(6);
- SkipToWord(); // 32-bit alignment
-
+ SkipToFourByteBoundary(); // 32-bit alignment
+
// Figure out where the end of this blob will be including tail padding.
- size_t NewEnd = NextChar+((NumElts+3)&~3);
-
+ 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)) {
+ if (!canSkipToPos(NewEnd/8)) {
Vals.append(NumElts, 0);
NextChar = BitStream->getBitcodeBytes().getExtent();
break;
}
-
- // Otherwise, read the number of bytes. If we can return a reference to
- // the data, do so to avoid copying it.
- if (BlobStart) {
- *BlobStart = (const char*)BitStream->getBitcodeBytes().getPointer(
- NextChar, NumElts);
- *BlobLen = NumElts;
+
+ // Otherwise, inform the streamer that we need these bytes in memory.
+ const char *Ptr = (const char*)
+ BitStream->getBitcodeBytes().getPointer(CurBitPos/8, NumElts);
+
+ // If we can return a reference to the data, do so to avoid copying it.
+ if (Blob) {
+ *Blob = StringRef(Ptr, NumElts);
} else {
- for (; NumElts; ++NextChar, --NumElts)
- Vals.push_back(getByte(NextChar));
+ // Otherwise, unpack into Vals with zero extension.
+ for (; NumElts; --NumElts)
+ Vals.push_back((unsigned char)*Ptr++);
}
// Skip over tail padding.
- NextChar = NewEnd;
+ JumpToBit(NewEnd);
}
-
- unsigned Code = (unsigned)Vals[0];
- Vals.erase(Vals.begin());
+
return Code;
}
BitCodeAbbrev *Abbv = new BitCodeAbbrev();
unsigned NumOpInfo = ReadVBR(5);
for (unsigned i = 0; i != NumOpInfo; ++i) {
- bool IsLiteral = Read(1) ? true : false;
+ bool IsLiteral = Read(1);
if (IsLiteral) {
Abbv->Add(BitCodeAbbrevOp(ReadVBR64(8)));
continue;
}
-
+
BitCodeAbbrevOp::Encoding E = (BitCodeAbbrevOp::Encoding)Read(3);
- if (BitCodeAbbrevOp::hasEncodingData(E))
- Abbv->Add(BitCodeAbbrevOp(E, ReadVBR64(5)));
- else
+ 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(Abbv);
}
// If this is the second stream to get to the block info block, skip it.
if (BitStream->hasBlockInfoRecords())
return SkipBlock();
-
+
if (EnterSubBlock(bitc::BLOCKINFO_BLOCK_ID)) return true;
-
+
SmallVector<uint64_t, 64> Record;
- BitstreamReader::BlockInfo *CurBlockInfo = 0;
-
+ BitstreamReader::BlockInfo *CurBlockInfo = nullptr;
+
// Read all the records for this module.
while (1) {
- unsigned Code = ReadCode();
- if (Code == bitc::END_BLOCK)
- return ReadBlockEnd();
- if (Code == bitc::ENTER_SUBBLOCK) {
- ReadSubBlockID();
- if (SkipBlock()) return true;
- continue;
+ BitstreamEntry Entry = advanceSkippingSubblocks(AF_DontAutoprocessAbbrevs);
+
+ switch (Entry.Kind) {
+ case llvm::BitstreamEntry::SubBlock: // Handled for us already.
+ case llvm::BitstreamEntry::Error:
+ return true;
+ case llvm::BitstreamEntry::EndBlock:
+ return false;
+ case llvm::BitstreamEntry::Record:
+ // The interesting case.
+ break;
}
-
+
// Read abbrev records, associate them with CurBID.
- if (Code == bitc::DEFINE_ABBREV) {
+ if (Entry.ID == bitc::DEFINE_ABBREV) {
if (!CurBlockInfo) return true;
ReadAbbrevRecord();
-
+
// ReadAbbrevRecord installs the abbrev in CurAbbrevs. Move it to the
// appropriate BlockInfo.
- BitCodeAbbrev *Abbv = CurAbbrevs.back();
+ CurBlockInfo->Abbrevs.push_back(std::move(CurAbbrevs.back()));
CurAbbrevs.pop_back();
- CurBlockInfo->Abbrevs.push_back(Abbv);
continue;
}
-
+
// Read a record.
Record.clear();
- switch (ReadRecord(Code, Record)) {
+ switch (readRecord(Entry.ID, Record)) {
default: break; // Default behavior, ignore unknown content.
case bitc::BLOCKINFO_CODE_SETBID:
if (Record.size() < 1) return true;
}
}
-