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 }
84