#define BITSTREAM_READER_H
#include "llvm/Bitcode/BitCodes.h"
-#include "llvm/ADT/SmallVector.h"
-#include <cassert>
+#include <vector>
namespace llvm {
// CurCodeSize - This is the declared size of code values used for the current
// block, in bits.
unsigned CurCodeSize;
+
+ /// CurAbbrevs - Abbrevs installed at in this block.
+ std::vector<BitCodeAbbrev*> CurAbbrevs;
- /// BlockScope - This tracks the codesize of parent blocks.
- SmallVector<unsigned, 8> BlockScope;
+ struct Block {
+ unsigned PrevCodeSize;
+ std::vector<BitCodeAbbrev*> PrevAbbrevs;
+ explicit Block(unsigned PCS) : PrevCodeSize(PCS) {}
+ };
+ /// BlockScope - This tracks the codesize of parent blocks.
+ SmallVector<Block, 8> BlockScope;
+
+ /// FirstChar - This remembers the first byte of the stream.
+ const unsigned char *FirstChar;
public:
BitstreamReader(const unsigned char *Start, const unsigned char *End)
- : NextChar(Start), LastChar(End) {
+ : NextChar(Start), LastChar(End), FirstChar(Start) {
assert(((End-Start) & 3) == 0 &&"Bitcode stream not a multiple of 4 bytes");
CurWord = 0;
BitsInCurWord = 0;
CurCodeSize = 2;
}
+ ~BitstreamReader() {
+ // Abbrevs could still exist if the stream was broken. If so, don't leak
+ // them.
+ for (unsigned i = 0, e = CurAbbrevs.size(); i != e; ++i)
+ delete CurAbbrevs[i];
+
+ for (unsigned S = 0, e = BlockScope.size(); S != e; ++S) {
+ std::vector<BitCodeAbbrev*> &Abbrevs = BlockScope[S].PrevAbbrevs;
+ for (unsigned i = 0, e = Abbrevs.size(); i != e; ++i)
+ delete Abbrevs[i];
+ }
+ }
+
bool AtEndOfStream() const { return NextChar == LastChar; }
+ /// GetCurrentBitNo - Return the bit # of the bit we are reading.
+ uint64_t GetCurrentBitNo() const {
+ return (NextChar-FirstChar)*8 + (32-BitsInCurWord);
+ }
+
+
uint32_t Read(unsigned NumBits) {
// If the field is fully contained by CurWord, return it quickly.
if (BitsInCurWord >= NumBits) {
return R;
}
+ uint64_t Read64(unsigned NumBits) {
+ if (NumBits <= 32) return Read(NumBits);
+
+ uint64_t V = Read(32);
+ return V | (uint64_t)Read(NumBits-32) << 32;
+ }
+
uint32_t ReadVBR(unsigned NumBits) {
uint32_t Piece = Read(NumBits);
- if ((Piece & (1U << NumBits-1)) == 0)
+ if ((Piece & (1U << (NumBits-1))) == 0)
return Piece;
uint32_t Result = 0;
while (1) {
Result |= (Piece & ((1U << (NumBits-1))-1)) << NextBit;
- if ((Piece & (1U << NumBits-1)) == 0)
+ if ((Piece & (1U << (NumBits-1))) == 0)
return Result;
NextBit += NumBits-1;
uint64_t ReadVBR64(unsigned NumBits) {
uint64_t Piece = Read(NumBits);
- if ((Piece & (1U << NumBits-1)) == 0)
+ if ((Piece & (1U << (NumBits-1))) == 0)
return Piece;
uint64_t Result = 0;
while (1) {
Result |= (Piece & ((1U << (NumBits-1))-1)) << NextBit;
- if ((Piece & (1U << NumBits-1)) == 0)
+ if ((Piece & (1U << (NumBits-1))) == 0)
return Result;
NextBit += NumBits-1;
/// EnterSubBlock - Having read the ENTER_SUBBLOCK abbrevid, read and enter
/// the block, returning the BlockID of the block we just entered.
bool EnterSubBlock() {
- BlockScope.push_back(CurCodeSize);
+ BlockScope.push_back(Block(CurCodeSize));
+ BlockScope.back().PrevAbbrevs.swap(CurAbbrevs);
// Get the codesize of this block.
CurCodeSize = ReadVBR(bitc::CodeLenWidth);
// Block tail:
// [END_BLOCK, <align4bytes>]
SkipToWord();
- CurCodeSize = BlockScope.back();
+ CurCodeSize = BlockScope.back().PrevCodeSize;
+
+ // Delete abbrevs from popped scope.
+ for (unsigned i = 0, e = CurAbbrevs.size(); i != e; ++i)
+ delete CurAbbrevs[i];
+
+ BlockScope.back().PrevAbbrevs.swap(CurAbbrevs);
BlockScope.pop_back();
return false;
}
return Code;
}
- assert(0 && "Reading with abbrevs not implemented!");
+ unsigned AbbrevNo = AbbrevID-bitc::FIRST_ABBREV;
+ assert(AbbrevNo < CurAbbrevs.size() && "Invalid abbrev #!");
+ BitCodeAbbrev *Abbv = CurAbbrevs[AbbrevNo];
+
+ for (unsigned i = 0, e = Abbv->getNumOperandInfos(); i != e; ++i) {
+ const BitCodeAbbrevOp &Op = Abbv->getOperandInfo(i);
+ if (Op.isLiteral()) {
+ // If the abbrev specifies the literal value to use, use it.
+ Vals.push_back(Op.getLiteralValue());
+ } else {
+ // Decode the value as we are commanded.
+ switch (Op.getEncoding()) {
+ default: assert(0 && "Unknown encoding!");
+ case BitCodeAbbrevOp::FixedWidth:
+ Vals.push_back(Read(Op.getEncodingData()));
+ break;
+ case BitCodeAbbrevOp::VBR:
+ Vals.push_back(ReadVBR64(Op.getEncodingData()));
+ break;
+ }
+ }
+ }
+
+ unsigned Code = Vals[0];
+ Vals.erase(Vals.begin());
+ return Code;
}
+ //===--------------------------------------------------------------------===//
+ // Abbrev Processing
+ //===--------------------------------------------------------------------===//
+
+ void ReadAbbrevRecord() {
+ BitCodeAbbrev *Abbv = new 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)) {
+ Abbv->Add(BitCodeAbbrevOp(E, ReadVBR64(5)));
+ } else {
+ assert(0 && "unimp");
+ }
+ }
+ CurAbbrevs.push_back(Abbv);
+ }
};
} // End llvm namespace
#endif
-
-
\ No newline at end of file
projects / oota-llvm.git / blobdiff