1 //===- MSFBuilder.h - MSF Directory & Metadata Builder ----------*- C++ -*-===// 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 #ifndef LLVM_DEBUGINFO_MSF_MSFBUILDER_H 11 #define LLVM_DEBUGINFO_MSF_MSFBUILDER_H 12 13 #include "llvm/ADT/ArrayRef.h" 14 #include "llvm/ADT/BitVector.h" 15 #include "llvm/DebugInfo/MSF/MSFCommon.h" 16 #include "llvm/Support/Allocator.h" 17 #include "llvm/Support/Error.h" 18 #include <cstdint> 19 #include <utility> 20 #include <vector> 21 22 namespace llvm { 23 namespace msf { 24 25 class MSFBuilder { 26 public: 27 /// \brief Create a new `MSFBuilder`. 28 /// 29 /// \param BlockSize The internal block size used by the PDB file. See 30 /// isValidBlockSize() for a list of valid block sizes. 31 /// 32 /// \param MinBlockCount Causes the builder to reserve up front space for 33 /// at least `MinBlockCount` blocks. This is useful when using `MSFBuilder` 34 /// to read an existing MSF that you want to write back out later. The 35 /// original MSF file's SuperBlock contains the exact number of blocks used 36 /// by the file, so is a good hint as to how many blocks the new MSF file 37 /// will contain. Furthermore, it is actually necessary in this case. To 38 /// preserve stability of the file's layout, it is helpful to try to keep 39 /// all streams mapped to their original block numbers. To ensure that this 40 /// is possible, space for all blocks must be allocated beforehand so that 41 /// streams can be assigned to them. 42 /// 43 /// \param CanGrow If true, any operation which results in an attempt to 44 /// locate a free block when all available blocks have been exhausted will 45 /// allocate a new block, thereby growing the size of the final MSF file. 46 /// When false, any such attempt will result in an error. This is especially 47 /// useful in testing scenarios when you know your test isn't going to do 48 /// anything to increase the size of the file, so having an Error returned if 49 /// it were to happen would catch a programming error 50 /// 51 /// \returns an llvm::Error representing whether the operation succeeded or 52 /// failed. Currently the only way this can fail is if an invalid block size 53 /// is specified, or `MinBlockCount` does not leave enough room for the 54 /// mandatory reserved blocks required by an MSF file. 55 static Expected<MSFBuilder> create(BumpPtrAllocator &Allocator, 56 uint32_t BlockSize, 57 uint32_t MinBlockCount = 0, 58 bool CanGrow = true); 59 60 /// Request the block map to be at a specific block address. This is useful 61 /// when editing a MSF and you want the layout to be as stable as possible. 62 Error setBlockMapAddr(uint32_t Addr); 63 Error setDirectoryBlocksHint(ArrayRef<uint32_t> DirBlocks); 64 void setFreePageMap(uint32_t Fpm); 65 void setUnknown1(uint32_t Unk1); 66 67 /// Add a stream to the MSF file with the given size, occupying the given 68 /// list of blocks. This is useful when reading a MSF file and you want a 69 /// particular stream to occupy the original set of blocks. If the given 70 /// blocks are already allocated, or if the number of blocks specified is 71 /// incorrect for the given stream size, this function will return an Error. 72 Expected<uint32_t> addStream(uint32_t Size, ArrayRef<uint32_t> Blocks); 73 74 /// Add a stream to the MSF file with the given size, occupying any available 75 /// blocks that the builder decides to use. This is useful when building a 76 /// new PDB file from scratch and you don't care what blocks a stream occupies 77 /// but you just want it to work. 78 Expected<uint32_t> addStream(uint32_t Size); 79 80 /// Update the size of an existing stream. This will allocate or deallocate 81 /// blocks as needed to match the requested size. This can fail if `CanGrow` 82 /// was set to false when initializing the `MSFBuilder`. 83 Error setStreamSize(uint32_t Idx, uint32_t Size); 84 85 /// Get the total number of streams in the MSF layout. This should return 1 86 /// for every call to `addStream`. 87 uint32_t getNumStreams() const; 88 89 /// Get the size of a stream by index. 90 uint32_t getStreamSize(uint32_t StreamIdx) const; 91 92 /// Get the list of blocks allocated to a particular stream. 93 ArrayRef<uint32_t> getStreamBlocks(uint32_t StreamIdx) const; 94 95 /// Get the total number of blocks that will be allocated to actual data in 96 /// this MSF file. 97 uint32_t getNumUsedBlocks() const; 98 99 /// Get the total number of blocks that exist in the MSF file but are not 100 /// allocated to any valid data. 101 uint32_t getNumFreeBlocks() const; 102 103 /// Get the total number of blocks in the MSF file. In practice this is equal 104 /// to `getNumUsedBlocks() + getNumFreeBlocks()`. 105 uint32_t getTotalBlockCount() const; 106 107 /// Check whether a particular block is allocated or free. 108 bool isBlockFree(uint32_t Idx) const; 109 110 /// Finalize the layout and build the headers and structures that describe the 111 /// MSF layout and can be written directly to the MSF file. 112 Expected<MSFLayout> build(); 113 114 BumpPtrAllocator &getAllocator() { return Allocator; } 115 116 private: 117 MSFBuilder(uint32_t BlockSize, uint32_t MinBlockCount, bool CanGrow, 118 BumpPtrAllocator &Allocator); 119 120 Error allocateBlocks(uint32_t NumBlocks, MutableArrayRef<uint32_t> Blocks); 121 uint32_t computeDirectoryByteSize() const; 122 123 using BlockList = std::vector<uint32_t>; 124 125 BumpPtrAllocator &Allocator; 126 127 bool IsGrowable; 128 uint32_t FreePageMap; 129 uint32_t Unknown1 = 0; 130 uint32_t BlockSize; 131 uint32_t MininumBlocks; 132 uint32_t BlockMapAddr; 133 BitVector FreeBlocks; 134 std::vector<uint32_t> DirectoryBlocks; 135 std::vector<std::pair<uint32_t, BlockList>> StreamData; 136 }; 137 138 } // end namespace msf 139 } // end namespace llvm 140 141 #endif // LLVM_DEBUGINFO_MSF_MSFBUILDER_H 142
