LLVM 19.0.0git
BitcodeReader.h
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1//===- llvm/Bitcode/BitcodeReader.h - Bitcode reader ------------*- C++ -*-===//
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// This header defines interfaces to read LLVM bitcode files/streams.
10//
11//===----------------------------------------------------------------------===//
12
13#ifndef LLVM_BITCODE_BITCODEREADER_H
14#define LLVM_BITCODE_BITCODEREADER_H
15
16#include "llvm/ADT/ArrayRef.h"
17#include "llvm/ADT/StringRef.h"
19#include "llvm/IR/GlobalValue.h"
20#include "llvm/Support/Endian.h"
21#include "llvm/Support/Error.h"
24#include <cstdint>
25#include <memory>
26#include <optional>
27#include <string>
28#include <system_error>
29#include <vector>
30namespace llvm {
31
32class LLVMContext;
33class Module;
34class MemoryBuffer;
35class Metadata;
36class ModuleSummaryIndex;
37class Type;
38class Value;
39
40// Callback to override the data layout string of an imported bitcode module.
41// The first argument is the target triple, the second argument the data layout
42// string from the input, or a default string. It will be used if the callback
43// returns std::nullopt.
44typedef std::function<std::optional<std::string>(StringRef, StringRef)>
46
47typedef std::function<Type *(unsigned)> GetTypeByIDTy;
48
49typedef std::function<unsigned(unsigned, unsigned)> GetContainedTypeIDTy;
50
51typedef std::function<void(Value *, unsigned, GetTypeByIDTy,
54
55typedef std::function<void(Metadata **, unsigned, GetTypeByIDTy,
58
59// These functions are for converting Expected/Error values to
60// ErrorOr/std::error_code for compatibility with legacy clients. FIXME:
61// Remove these functions once no longer needed by the C and libLTO APIs.
62
63std::error_code errorToErrorCodeAndEmitErrors(LLVMContext &Ctx, Error Err);
64
65template <typename T>
67 if (!Val)
69 return std::move(*Val);
70}
71
73 std::optional<DataLayoutCallbackFuncTy> DataLayout;
74 /// The ValueType callback is called for every function definition or
75 /// declaration and allows accessing the type information, also behind
76 /// pointers. This can be useful, when the opaque pointer upgrade cleans all
77 /// type information behind pointers.
78 /// The second argument to ValueTypeCallback is the type ID of the
79 /// function, the two passed functions can be used to extract type
80 /// information.
81 std::optional<ValueTypeCallbackTy> ValueType;
82 /// The MDType callback is called for every value in metadata.
83 std::optional<MDTypeCallbackTy> MDType;
84
85 ParserCallbacks() = default;
88};
89
90 struct BitcodeFileContents;
91
92 /// Basic information extracted from a bitcode module to be used for LTO.
98 };
99
100 /// Represents a module in a bitcode file.
102 // This covers the identification (if present) and module blocks.
103 ArrayRef<uint8_t> Buffer;
104 StringRef ModuleIdentifier;
105
106 // The string table used to interpret this module.
107 StringRef Strtab;
108
109 // The bitstream location of the IDENTIFICATION_BLOCK.
110 uint64_t IdentificationBit;
111
112 // The bitstream location of this module's MODULE_BLOCK.
113 uint64_t ModuleBit;
114
115 BitcodeModule(ArrayRef<uint8_t> Buffer, StringRef ModuleIdentifier,
116 uint64_t IdentificationBit, uint64_t ModuleBit)
117 : Buffer(Buffer), ModuleIdentifier(ModuleIdentifier),
118 IdentificationBit(IdentificationBit), ModuleBit(ModuleBit) {}
119
120 // Calls the ctor.
123
125 getModuleImpl(LLVMContext &Context, bool MaterializeAll,
126 bool ShouldLazyLoadMetadata, bool IsImporting,
127 ParserCallbacks Callbacks = {});
128
129 public:
131 return StringRef((const char *)Buffer.begin(), Buffer.size());
132 }
133
134 StringRef getStrtab() const { return Strtab; }
135
136 StringRef getModuleIdentifier() const { return ModuleIdentifier; }
137
138 /// Read the bitcode module and prepare for lazy deserialization of function
139 /// bodies. If ShouldLazyLoadMetadata is true, lazily load metadata as well.
140 /// If IsImporting is true, this module is being parsed for ThinLTO
141 /// importing into another module.
143 getLazyModule(LLVMContext &Context, bool ShouldLazyLoadMetadata,
144 bool IsImporting, ParserCallbacks Callbacks = {});
145
146 /// Read the entire bitcode module and return it.
147 Expected<std::unique_ptr<Module>>
148 parseModule(LLVMContext &Context, ParserCallbacks Callbacks = {});
149
150 /// Returns information about the module to be used for LTO: whether to
151 /// compile with ThinLTO, and whether it has a summary.
152 Expected<BitcodeLTOInfo> getLTOInfo();
153
154 /// Parse the specified bitcode buffer, returning the module summary index.
155 Expected<std::unique_ptr<ModuleSummaryIndex>> getSummary();
156
157 /// Parse the specified bitcode buffer and merge its module summary index
158 /// into CombinedIndex.
159 Error
160 readSummary(ModuleSummaryIndex &CombinedIndex, StringRef ModulePath,
161 std::function<bool(GlobalValue::GUID)> IsPrevailing = nullptr);
162 };
163
165 std::vector<BitcodeModule> Mods;
167 };
168
169 /// Returns the contents of a bitcode file. This includes the raw contents of
170 /// the symbol table embedded in the bitcode file. Clients which require a
171 /// symbol table should prefer to use irsymtab::read instead of this function
172 /// because it creates a reader for the irsymtab and handles upgrading bitcode
173 /// files without a symbol table or with an old symbol table.
175
176 /// Returns a list of modules in the specified bitcode buffer.
179
180 /// Read the header of the specified bitcode buffer and prepare for lazy
181 /// deserialization of function bodies. If ShouldLazyLoadMetadata is true,
182 /// lazily load metadata as well. If IsImporting is true, this module is
183 /// being parsed for ThinLTO importing into another module.
186 bool ShouldLazyLoadMetadata = false,
187 bool IsImporting = false,
188 ParserCallbacks Callbacks = {});
189
190 /// Like getLazyBitcodeModule, except that the module takes ownership of
191 /// the memory buffer if successful. If successful, this moves Buffer. On
192 /// error, this *does not* move Buffer. If IsImporting is true, this module is
193 /// being parsed for ThinLTO importing into another module.
194 Expected<std::unique_ptr<Module>> getOwningLazyBitcodeModule(
195 std::unique_ptr<MemoryBuffer> &&Buffer, LLVMContext &Context,
196 bool ShouldLazyLoadMetadata = false, bool IsImporting = false,
197 ParserCallbacks Callbacks = {});
198
199 /// Read the header of the specified bitcode buffer and extract just the
200 /// triple information. If successful, this returns a string. On error, this
201 /// returns "".
202 Expected<std::string> getBitcodeTargetTriple(MemoryBufferRef Buffer);
203
204 /// Return true if \p Buffer contains a bitcode file with ObjC code (category
205 /// or class) in it.
206 Expected<bool> isBitcodeContainingObjCCategory(MemoryBufferRef Buffer);
207
208 /// Read the header of the specified bitcode buffer and extract just the
209 /// producer string information. If successful, this returns a string. On
210 /// error, this returns "".
211 Expected<std::string> getBitcodeProducerString(MemoryBufferRef Buffer);
212
213 /// Read the specified bitcode file, returning the module.
214 Expected<std::unique_ptr<Module>>
215 parseBitcodeFile(MemoryBufferRef Buffer, LLVMContext &Context,
216 ParserCallbacks Callbacks = {});
217
218 /// Returns LTO information for the specified bitcode file.
219 Expected<BitcodeLTOInfo> getBitcodeLTOInfo(MemoryBufferRef Buffer);
220
221 /// Parse the specified bitcode buffer, returning the module summary index.
222 Expected<std::unique_ptr<ModuleSummaryIndex>>
223 getModuleSummaryIndex(MemoryBufferRef Buffer);
224
225 /// Parse the specified bitcode buffer and merge the index into CombinedIndex.
226 Error readModuleSummaryIndex(MemoryBufferRef Buffer,
227 ModuleSummaryIndex &CombinedIndex);
228
229 /// Parse the module summary index out of an IR file and return the module
230 /// summary index object if found, or an empty summary if not. If Path refers
231 /// to an empty file and IgnoreEmptyThinLTOIndexFile is true, then
232 /// this function will return nullptr.
233 Expected<std::unique_ptr<ModuleSummaryIndex>>
234 getModuleSummaryIndexForFile(StringRef Path,
235 bool IgnoreEmptyThinLTOIndexFile = false);
236
237 /// isBitcodeWrapper - Return true if the given bytes are the magic bytes
238 /// for an LLVM IR bitcode wrapper.
239 inline bool isBitcodeWrapper(const unsigned char *BufPtr,
240 const unsigned char *BufEnd) {
241 // See if you can find the hidden message in the magic bytes :-).
242 // (Hint: it's a little-endian encoding.)
243 return BufPtr != BufEnd &&
244 BufPtr[0] == 0xDE &&
245 BufPtr[1] == 0xC0 &&
246 BufPtr[2] == 0x17 &&
247 BufPtr[3] == 0x0B;
248 }
249
250 /// isRawBitcode - Return true if the given bytes are the magic bytes for
251 /// raw LLVM IR bitcode (without a wrapper).
252 inline bool isRawBitcode(const unsigned char *BufPtr,
253 const unsigned char *BufEnd) {
254 // These bytes sort of have a hidden message, but it's not in
255 // little-endian this time, and it's a little redundant.
256 return BufPtr != BufEnd &&
257 BufPtr[0] == 'B' &&
258 BufPtr[1] == 'C' &&
259 BufPtr[2] == 0xc0 &&
260 BufPtr[3] == 0xde;
261 }
262
263 /// isBitcode - Return true if the given bytes are the magic bytes for
264 /// LLVM IR bitcode, either with or without a wrapper.
265 inline bool isBitcode(const unsigned char *BufPtr,
266 const unsigned char *BufEnd) {
267 return isBitcodeWrapper(BufPtr, BufEnd) ||
268 isRawBitcode(BufPtr, BufEnd);
269 }
270
271 /// SkipBitcodeWrapperHeader - Some systems wrap bc files with a special
272 /// header for padding or other reasons. The format of this header is:
273 ///
274 /// struct bc_header {
275 /// uint32_t Magic; // 0x0B17C0DE
276 /// uint32_t Version; // Version, currently always 0.
277 /// uint32_t BitcodeOffset; // Offset to traditional bitcode file.
278 /// uint32_t BitcodeSize; // Size of traditional bitcode file.
279 /// ... potentially other gunk ...
280 /// };
281 ///
282 /// This function is called when we find a file with a matching magic number.
283 /// In this case, skip down to the subsection of the file that is actually a
284 /// BC file.
285 /// If 'VerifyBufferSize' is true, check that the buffer is large enough to
286 /// contain the whole bitcode file.
287 inline bool SkipBitcodeWrapperHeader(const unsigned char *&BufPtr,
288 const unsigned char *&BufEnd,
289 bool VerifyBufferSize) {
290 // Must contain the offset and size field!
291 if (unsigned(BufEnd - BufPtr) < BWH_SizeField + 4)
292 return true;
293
295 unsigned Size = support::endian::read32le(&BufPtr[BWH_SizeField]);
296 uint64_t BitcodeOffsetEnd = (uint64_t)Offset + (uint64_t)Size;
297
298 // Verify that Offset+Size fits in the file.
299 if (VerifyBufferSize && BitcodeOffsetEnd > uint64_t(BufEnd-BufPtr))
300 return true;
301 BufPtr += Offset;
302 BufEnd = BufPtr+Size;
303 return false;
304 }
305
306 APInt readWideAPInt(ArrayRef<uint64_t> Vals, unsigned TypeBits);
307
308 const std::error_category &BitcodeErrorCategory();
309 enum class BitcodeError { CorruptedBitcode = 1 };
310 inline std::error_code make_error_code(BitcodeError E) {
311 return std::error_code(static_cast<int>(E), BitcodeErrorCategory());
312 }
313
314} // end namespace llvm
315
316namespace std {
317
318template <> struct is_error_code_enum<llvm::BitcodeError> : std::true_type {};
319
320} // end namespace std
321
322#endif // LLVM_BITCODE_BITCODEREADER_H
static GCRegistry::Add< CoreCLRGC > E("coreclr", "CoreCLR-compatible GC")
RelocType Type
Definition: COFFYAML.cpp:391
uint64_t Size
Provides ErrorOr<T> smart pointer.
Machine Check Debug Module
ArrayRef - Represent a constant reference to an array (0 or more elements consecutively in memory),...
Definition: ArrayRef.h:41
size_t size() const
size - Get the array size.
Definition: ArrayRef.h:165
iterator begin() const
Definition: ArrayRef.h:153
Represents a module in a bitcode file.
StringRef getModuleIdentifier() const
Expected< std::unique_ptr< ModuleSummaryIndex > > getSummary()
Parse the specified bitcode buffer, returning the module summary index.
Expected< BitcodeLTOInfo > getLTOInfo()
Returns information about the module to be used for LTO: whether to compile with ThinLTO,...
StringRef getBuffer() const
Error readSummary(ModuleSummaryIndex &CombinedIndex, StringRef ModulePath, std::function< bool(GlobalValue::GUID)> IsPrevailing=nullptr)
Parse the specified bitcode buffer and merge its module summary index into CombinedIndex.
Expected< std::unique_ptr< Module > > parseModule(LLVMContext &Context, ParserCallbacks Callbacks={})
Read the entire bitcode module and return it.
StringRef getStrtab() const
friend Expected< BitcodeFileContents > getBitcodeFileContents(MemoryBufferRef Buffer)
Returns the contents of a bitcode file.
Expected< std::unique_ptr< Module > > getLazyModule(LLVMContext &Context, bool ShouldLazyLoadMetadata, bool IsImporting, ParserCallbacks Callbacks={})
Read the bitcode module and prepare for lazy deserialization of function bodies.
A parsed version of the target data layout string in and methods for querying it.
Definition: DataLayout.h:110
Represents either an error or a value T.
Definition: ErrorOr.h:56
Lightweight error class with error context and mandatory checking.
Definition: Error.h:160
Tagged union holding either a T or a Error.
Definition: Error.h:474
Error takeError()
Take ownership of the stored error.
Definition: Error.h:601
uint64_t GUID
Declare a type to represent a global unique identifier for a global value.
Definition: GlobalValue.h:586
This is an important class for using LLVM in a threaded context.
Definition: LLVMContext.h:67
Root of the metadata hierarchy.
Definition: Metadata.h:62
StringRef - Represent a constant reference to a string, i.e.
Definition: StringRef.h:50
The instances of the Type class are immutable: once they are created, they are never changed.
Definition: Type.h:45
LLVM Value Representation.
Definition: Value.h:74
uint32_t read32le(const void *P)
Definition: Endian.h:409
This is an optimization pass for GlobalISel generic memory operations.
Definition: AddressRanges.h:18
@ Offset
Definition: DWP.cpp:456
const std::error_category & BitcodeErrorCategory()
Expected< std::unique_ptr< Module > > parseBitcodeFile(MemoryBufferRef Buffer, LLVMContext &Context, ParserCallbacks Callbacks={})
Read the specified bitcode file, returning the module.
std::error_code make_error_code(BitcodeError E)
std::function< Type *(unsigned)> GetTypeByIDTy
Definition: BitcodeReader.h:47
Expected< bool > isBitcodeContainingObjCCategory(MemoryBufferRef Buffer)
Return true if Buffer contains a bitcode file with ObjC code (category or class) in it.
std::function< unsigned(unsigned, unsigned)> GetContainedTypeIDTy
Definition: BitcodeReader.h:49
@ BWH_OffsetField
Definition: BitCodeEnums.h:29
@ BWH_SizeField
Definition: BitCodeEnums.h:30
Expected< std::string > getBitcodeTargetTriple(MemoryBufferRef Buffer)
Read the header of the specified bitcode buffer and extract just the triple information.
Expected< BitcodeFileContents > getBitcodeFileContents(MemoryBufferRef Buffer)
Returns the contents of a bitcode file.
ErrorOr< T > expectedToErrorOrAndEmitErrors(LLVMContext &Ctx, Expected< T > Val)
Definition: BitcodeReader.h:66
bool isRawBitcode(const unsigned char *BufPtr, const unsigned char *BufEnd)
isRawBitcode - Return true if the given bytes are the magic bytes for raw LLVM IR bitcode (without a ...
Expected< std::unique_ptr< ModuleSummaryIndex > > getModuleSummaryIndex(MemoryBufferRef Buffer)
Parse the specified bitcode buffer, returning the module summary index.
Expected< std::string > getBitcodeProducerString(MemoryBufferRef Buffer)
Read the header of the specified bitcode buffer and extract just the producer string information.
Expected< std::unique_ptr< Module > > getLazyBitcodeModule(MemoryBufferRef Buffer, LLVMContext &Context, bool ShouldLazyLoadMetadata=false, bool IsImporting=false, ParserCallbacks Callbacks={})
Read the header of the specified bitcode buffer and prepare for lazy deserialization of function bodi...
std::function< void(Metadata **, unsigned, GetTypeByIDTy, GetContainedTypeIDTy)> MDTypeCallbackTy
Definition: BitcodeReader.h:57
Expected< std::vector< BitcodeModule > > getBitcodeModuleList(MemoryBufferRef Buffer)
Returns a list of modules in the specified bitcode buffer.
Expected< BitcodeLTOInfo > getBitcodeLTOInfo(MemoryBufferRef Buffer)
Returns LTO information for the specified bitcode file.
bool SkipBitcodeWrapperHeader(const unsigned char *&BufPtr, const unsigned char *&BufEnd, bool VerifyBufferSize)
SkipBitcodeWrapperHeader - Some systems wrap bc files with a special header for padding or other reas...
bool isBitcodeWrapper(const unsigned char *BufPtr, const unsigned char *BufEnd)
isBitcodeWrapper - Return true if the given bytes are the magic bytes for an LLVM IR bitcode wrapper.
APInt readWideAPInt(ArrayRef< uint64_t > Vals, unsigned TypeBits)
std::function< void(Value *, unsigned, GetTypeByIDTy, GetContainedTypeIDTy)> ValueTypeCallbackTy
Definition: BitcodeReader.h:53
std::function< std::optional< std::string >(StringRef, StringRef)> DataLayoutCallbackFuncTy
Definition: BitcodeReader.h:45
bool isBitcode(const unsigned char *BufPtr, const unsigned char *BufEnd)
isBitcode - Return true if the given bytes are the magic bytes for LLVM IR bitcode,...
Error readModuleSummaryIndex(MemoryBufferRef Buffer, ModuleSummaryIndex &CombinedIndex)
Parse the specified bitcode buffer and merge the index into CombinedIndex.
Expected< std::unique_ptr< ModuleSummaryIndex > > getModuleSummaryIndexForFile(StringRef Path, bool IgnoreEmptyThinLTOIndexFile=false)
Parse the module summary index out of an IR file and return the module summary index object if found,...
Expected< std::unique_ptr< Module > > getOwningLazyBitcodeModule(std::unique_ptr< MemoryBuffer > &&Buffer, LLVMContext &Context, bool ShouldLazyLoadMetadata=false, bool IsImporting=false, ParserCallbacks Callbacks={})
Like getLazyBitcodeModule, except that the module takes ownership of the memory buffer if successful.
std::error_code errorToErrorCodeAndEmitErrors(LLVMContext &Ctx, Error Err)
Implement std::hash so that hash_code can be used in STL containers.
Definition: BitVector.h:858
std::vector< BitcodeModule > Mods
Basic information extracted from a bitcode module to be used for LTO.
Definition: BitcodeReader.h:93
std::optional< ValueTypeCallbackTy > ValueType
The ValueType callback is called for every function definition or declaration and allows accessing th...
Definition: BitcodeReader.h:81
std::optional< DataLayoutCallbackFuncTy > DataLayout
Definition: BitcodeReader.h:73
ParserCallbacks(DataLayoutCallbackFuncTy DataLayout)
Definition: BitcodeReader.h:86
std::optional< MDTypeCallbackTy > MDType
The MDType callback is called for every value in metadata.
Definition: BitcodeReader.h:83