lib/DebugInfo/MSF/MSFCommon.cpp

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