lib/DebugInfo/CodeView/RecordSerialization.cpp

   1 //===-- RecordSerialization.cpp -------------------------------------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 //
   9 // Utilities for serializing and deserializing CodeView records.
  10 //
  11 //===----------------------------------------------------------------------===//
  12
  13 #include "llvm/DebugInfo/CodeView/RecordSerialization.h"
  14 #include "llvm/ADT/APInt.h"
  15 #include "llvm/ADT/APSInt.h"
  16 #include "llvm/DebugInfo/CodeView/CodeViewError.h"
  17 #include "llvm/DebugInfo/CodeView/SymbolRecord.h"
  18 #include "llvm/DebugInfo/CodeView/TypeRecord.h"
  19 #include "llvm/Support/BinaryByteStream.h"
  20
  21 using namespace llvm;
  22 using namespace llvm::codeview;
  23 using namespace llvm::support;
  24
  25 /// Reinterpret a byte array as an array of characters. Does not interpret as
  26 /// a C string, as StringRef has several helpers (split) that make that easy.
  27 StringRef llvm::codeview::getBytesAsCharacters(ArrayRef<uint8_t> LeafData) {
  28   return StringRef(reinterpret_cast<const char *>(LeafData.data()),
  29                    LeafData.size());
  30 }
  31
  32 StringRef llvm::codeview::getBytesAsCString(ArrayRef<uint8_t> LeafData) {
  33   return getBytesAsCharacters(LeafData).split('\0').first;
  34 }
  35
  36 Error llvm::codeview::consume(BinaryStreamReader &Reader, APSInt &Num) {
  37   // Used to avoid overload ambiguity on APInt construtor.
  38   bool FalseVal = false;
  39   uint16_t Short;
  40   if (auto EC = Reader.readInteger(Short))
  41     return EC;
  42
  43   if (Short < LF_NUMERIC) {
  44     Num = APSInt(APInt(/*numBits=*/16, Short, /*isSigned=*/false),
  45                  /*isUnsigned=*/true);
  46     return Error::success();
  47   }
  48
  49   switch (Short) {
  50   case LF_CHAR: {
  51     int8_t N;
  52     if (auto EC = Reader.readInteger(N))
  53       return EC;
  54     Num = APSInt(APInt(8, N, true), false);
  55     return Error::success();
  56   }
  57   case LF_SHORT: {
  58     int16_t N;
  59     if (auto EC = Reader.readInteger(N))
  60       return EC;
  61     Num = APSInt(APInt(16, N, true), false);
  62     return Error::success();
  63   }
  64   case LF_USHORT: {
  65     uint16_t N;
  66     if (auto EC = Reader.readInteger(N))
  67       return EC;
  68     Num = APSInt(APInt(16, N, false), true);
  69     return Error::success();
  70   }
  71   case LF_LONG: {
  72     int32_t N;
  73     if (auto EC = Reader.readInteger(N))
  74       return EC;
  75     Num = APSInt(APInt(32, N, true), false);
  76     return Error::success();
  77   }
  78   case LF_ULONG: {
  79     uint32_t N;
  80     if (auto EC = Reader.readInteger(N))
  81       return EC;
  82     Num = APSInt(APInt(32, N, FalseVal), true);
  83     return Error::success();
  84   }
  85   case LF_QUADWORD: {
  86     int64_t N;
  87     if (auto EC = Reader.readInteger(N))
  88       return EC;
  89     Num = APSInt(APInt(64, N, true), false);
  90     return Error::success();
  91   }
  92   case LF_UQUADWORD: {
  93     uint64_t N;
  94     if (auto EC = Reader.readInteger(N))
  95       return EC;
  96     Num = APSInt(APInt(64, N, false), true);
  97     return Error::success();
  98   }
  99   }
 100   return make_error<CodeViewError>(cv_error_code::corrupt_record,
 101                                    "Buffer contains invalid APSInt type");
 102 }
 103
 104 Error llvm::codeview::consume(StringRef &Data, APSInt &Num) {
 105   ArrayRef<uint8_t> Bytes(Data.bytes_begin(), Data.bytes_end());
 106   BinaryByteStream S(Bytes, llvm::support::little);
 107   BinaryStreamReader SR(S);
 108   auto EC = consume(SR, Num);
 109   Data = Data.take_back(SR.bytesRemaining());
 110   return EC;
 111 }
 112
 113 /// Decode a numeric leaf value that is known to be a uint64_t.
 114 Error llvm::codeview::consume_numeric(BinaryStreamReader &Reader,
 115                                       uint64_t &Num) {
 116   APSInt N;
 117   if (auto EC = consume(Reader, N))
 118     return EC;
 119   if (N.isSigned() || !N.isIntN(64))
 120     return make_error<CodeViewError>(cv_error_code::corrupt_record,
 121                                      "Data is not a numeric value!");
 122   Num = N.getLimitedValue();
 123   return Error::success();
 124 }
 125
 126 Error llvm::codeview::consume(BinaryStreamReader &Reader, uint32_t &Item) {
 127   return Reader.readInteger(Item);
 128 }
 129
 130 Error llvm::codeview::consume(StringRef &Data, uint32_t &Item) {
 131   ArrayRef<uint8_t> Bytes(Data.bytes_begin(), Data.bytes_end());
 132   BinaryByteStream S(Bytes, llvm::support::little);
 133   BinaryStreamReader SR(S);
 134   auto EC = consume(SR, Item);
 135   Data = Data.take_back(SR.bytesRemaining());
 136   return EC;
 137 }
 138
 139 Error llvm::codeview::consume(BinaryStreamReader &Reader, int32_t &Item) {
 140   return Reader.readInteger(Item);
 141 }
 142
 143 Error llvm::codeview::consume(BinaryStreamReader &Reader, StringRef &Item) {
 144   if (Reader.empty())
 145     return make_error<CodeViewError>(cv_error_code::corrupt_record,
 146                                      "Null terminated string buffer is empty!");
 147
 148   return Reader.readCString(Item);
 149 }
 150
 151 Expected<CVSymbol> llvm::codeview::readSymbolFromStream(BinaryStreamRef Stream,
 152                                                         uint32_t Offset) {
 153   return readCVRecordFromStream<SymbolKind>(Stream, Offset);
 154 }