lib/DebugInfo/MSF/MSFCommon.cpp

   1 //===- MSFCommon.cpp - Common types and functions for MSF files -----------===//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file is distributed under the University of Illinois Open Source
   6 // License. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9
  10 #include "llvm/DebugInfo/MSF/MSFCommon.h"
  11 #include "llvm/DebugInfo/MSF/MSFError.h"
  12 #include "llvm/Support/Endian.h"
  13 #include "llvm/Support/Error.h"
  14 #include <cstdint>
  15 #include <cstring>
  16
  17 using namespace llvm;
  18 using namespace llvm::msf;
  19
  20 Error llvm::msf::validateSuperBlock(const SuperBlock &SB) {
  21   // Check the magic bytes.
  22   if (std::memcmp(SB.MagicBytes, Magic, sizeof(Magic)) != 0)
  23     return make_error<MSFError>(msf_error_code::invalid_format,
  24                                 "MSF magic header doesn't match");
  25
  26   if (!isValidBlockSize(SB.BlockSize))
  27     return make_error<MSFError>(msf_error_code::invalid_format,
  28                                 "Unsupported block size.");
  29
  30   // We don't support directories whose sizes aren't a multiple of four bytes.
  31   if (SB.NumDirectoryBytes % sizeof(support::ulittle32_t) != 0)
  32     return make_error<MSFError>(msf_error_code::invalid_format,
  33                                 "Directory size is not multiple of 4.");
  34
  35   // The number of blocks which comprise the directory is a simple function of
  36   // the number of bytes it contains.
  37   uint64_t NumDirectoryBlocks =
  38       bytesToBlocks(SB.NumDirectoryBytes, SB.BlockSize);
  39
  40   // The directory, as we understand it, is a block which consists of a list of
  41   // block numbers.  It is unclear what would happen if the number of blocks
  42   // couldn't fit on a single block.
  43   if (NumDirectoryBlocks > SB.BlockSize / sizeof(support::ulittle32_t))
  44     return make_error<MSFError>(msf_error_code::invalid_format,
  45                                 "Too many directory blocks.");
  46
  47   if (SB.BlockMapAddr == 0)
  48     return make_error<MSFError>(msf_error_code::invalid_format,
  49                                 "Block 0 is reserved");
  50
  51   if (SB.BlockMapAddr >= SB.NumBlocks)
  52     return make_error<MSFError>(msf_error_code::invalid_format,
  53                                 "Block map address is invalid.");
  54
  55   if (SB.FreeBlockMapBlock != 1 && SB.FreeBlockMapBlock != 2)
  56     return make_error<MSFError>(
  57         msf_error_code::invalid_format,
  58         "The free block map isn't at block 1 or block 2.");
  59
  60   return Error::success();
  61 }
  62
  63 MSFStreamLayout llvm::msf::getFpmStreamLayout(const MSFLayout &Msf,
  64                                               bool IncludeUnusedFpmData,
  65                                               bool AltFpm) {
  66   MSFStreamLayout FL;
  67   uint32_t NumFpmIntervals =
  68       getNumFpmIntervals(Msf, IncludeUnusedFpmData, AltFpm);
  69
  70   uint32_t FpmBlock = AltFpm ? Msf.alternateFpmBlock() : Msf.mainFpmBlock();
  71
  72   for (uint32_t I = 0; I < NumFpmIntervals; ++I) {
  73     FL.Blocks.push_back(support::ulittle32_t(FpmBlock));
  74     FpmBlock += msf::getFpmIntervalLength(Msf);
  75   }
  76
  77   if (IncludeUnusedFpmData)
  78     FL.Length = NumFpmIntervals * Msf.SB->BlockSize;
  79   else
  80     FL.Length = divideCeil(Msf.SB->NumBlocks, 8);
  81
  82   return FL;
  83 }