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
validateSuperBlock(const SuperBlock & SB)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
getFpmStreamLayout(const MSFLayout & Msf,bool IncludeUnusedFpmData,bool AltFpm)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 }
83