1//===-LTOModule.h - LLVM Link Time Optimizer ------------------------------===//
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 file declares the LTOModule class.
10//
11//===----------------------------------------------------------------------===//
12
13#ifndef LLVM_LTO_LEGACY_LTOMODULE_H
14#define LLVM_LTO_LEGACY_LTOMODULE_H
15
16#include "llvm-c/lto.h"
17#include "llvm/ADT/StringMap.h"
18#include "llvm/ADT/StringSet.h"
19#include "llvm/IR/Module.h"
20#include "llvm/LTO/LTO.h"
21#include "llvm/Object/IRObjectFile.h"
22#include "llvm/Object/ModuleSymbolTable.h"
23#include "llvm/Target/TargetMachine.h"
24#include <string>
25#include <vector>
26
27// Forward references to llvm classes.
28namespace llvm {
29 class Function;
30 class GlobalValue;
31 class MemoryBuffer;
32 class TargetOptions;
33 class Value;
34
35//===----------------------------------------------------------------------===//
36/// C++ class which implements the opaque lto_module_t type.
37///
38struct LTOModule {
39private:
40 struct NameAndAttributes {
41 StringRef name;
42 uint32_t attributes = 0;
43 bool isFunction = false;
44 const GlobalValue *symbol = nullptr;
45 };
46
47 std::unique_ptr<LLVMContext> OwnedContext;
48
49 std::string LinkerOpts;
50
51 std::unique_ptr<Module> Mod;
52 MemoryBufferRef MBRef;
53 ModuleSymbolTable SymTab;
54 std::unique_ptr<TargetMachine> _target;
55 std::vector<NameAndAttributes> _symbols;
56
57 // _defines and _undefines only needed to disambiguate tentative definitions
58 StringSet<> _defines;
59 StringMap<NameAndAttributes> _undefines;
60 std::vector<StringRef> _asm_undefines;
61
62 LTOModule(std::unique_ptr<Module> M, MemoryBufferRef MBRef,
63 TargetMachine *TM);
64
65public:
66 ~LTOModule();
67
68 /// Returns 'true' if the file or memory contents is LLVM bitcode.
69 static bool isBitcodeFile(const void *mem, size_t length);
70 static bool isBitcodeFile(StringRef path);
71
72 /// Returns 'true' if the Module is produced for ThinLTO.
73 bool isThinLTO();
74
75 /// Returns 'true' if the memory buffer is LLVM bitcode for the specified
76 /// triple.
77 static bool isBitcodeForTarget(MemoryBuffer *memBuffer,
78 StringRef triplePrefix);
79
80 /// Returns a string representing the producer identification stored in the
81 /// bitcode, or "" if the bitcode does not contains any.
82 ///
83 static std::string getProducerString(MemoryBuffer *Buffer);
84
85 /// Create a MemoryBuffer from a memory range with an optional name.
86 static std::unique_ptr<MemoryBuffer>
87 makeBuffer(const void *mem, size_t length, StringRef name = "");
88
89 /// Create an LTOModule. N.B. These methods take ownership of the buffer. The
90 /// caller must have initialized the Targets, the TargetMCs, the AsmPrinters,
91 /// and the AsmParsers by calling:
92 ///
93 /// InitializeAllTargets();
94 /// InitializeAllTargetMCs();
95 /// InitializeAllAsmPrinters();
96 /// InitializeAllAsmParsers();
97 static ErrorOr<std::unique_ptr<LTOModule>>
98 createFromFile(LLVMContext &Context, StringRef path,
99 const TargetOptions &options);
100 static ErrorOr<std::unique_ptr<LTOModule>>
101 createFromOpenFile(LLVMContext &Context, int fd, StringRef path, size_t size,
102 const TargetOptions &options);
103 static ErrorOr<std::unique_ptr<LTOModule>>
104 createFromOpenFileSlice(LLVMContext &Context, int fd, StringRef path,
105 size_t map_size, off_t offset,
106 const TargetOptions &options);
107 static ErrorOr<std::unique_ptr<LTOModule>>
108 createFromBuffer(LLVMContext &Context, const void *mem, size_t length,
109 const TargetOptions &options, StringRef path = "");
110 static ErrorOr<std::unique_ptr<LTOModule>>
111 createInLocalContext(std::unique_ptr<LLVMContext> Context, const void *mem,
112 size_t length, const TargetOptions &options,
113 StringRef path);
114
115 const Module &getModule() const { return *Mod; }
116 Module &getModule() { return *Mod; }
117
118 std::unique_ptr<Module> takeModule() { return std::move(Mod); }
119
120 /// Return the Module's target triple.
121 const std::string &getTargetTriple() {
122 return getModule().getTargetTriple();
123 }
124
125 /// Set the Module's target triple.
126 void setTargetTriple(StringRef Triple) {
127 getModule().setTargetTriple(Triple);
128 }
129
130 /// Get the number of symbols
131 uint32_t getSymbolCount() {
132 return _symbols.size();
133 }
134
135 /// Get the attributes for a symbol at the specified index.
136 lto_symbol_attributes getSymbolAttributes(uint32_t index) {
137 if (index < _symbols.size())
138 return lto_symbol_attributes(_symbols[index].attributes);
139 return lto_symbol_attributes(0);
140 }
141
142 /// Get the name of the symbol at the specified index.
143 StringRef getSymbolName(uint32_t index) {
144 if (index < _symbols.size())
145 return _symbols[index].name;
146 return StringRef();
147 }
148
149 const GlobalValue *getSymbolGV(uint32_t index) {
150 if (index < _symbols.size())
151 return _symbols[index].symbol;
152 return nullptr;
153 }
154
155 StringRef getLinkerOpts() { return LinkerOpts; }
156
157 const std::vector<StringRef> &getAsmUndefinedRefs() { return _asm_undefines; }
158
159 static lto::InputFile *createInputFile(const void *buffer, size_t buffer_size,
160 const char *path, std::string &out_error);
161
162 static size_t getDependentLibraryCount(lto::InputFile *input);
163
164 static const char *getDependentLibrary(lto::InputFile *input, size_t index, size_t *size);
165
166 Expected<uint32_t> getMachOCPUType() const;
167
168 Expected<uint32_t> getMachOCPUSubType() const;
169
170 /// Returns true if the module has either the @llvm.global_ctors or the
171 /// @llvm.global_dtors symbol. Otherwise returns false.
172 bool hasCtorDtor() const;
173
174private:
175 /// Parse metadata from the module
176 // FIXME: it only parses "llvm.linker.options" metadata at the moment
177 // FIXME: can't access metadata in lazily loaded modules
178 void parseMetadata();
179
180 /// Parse the symbols from the module and model-level ASM and add them to
181 /// either the defined or undefined lists.
182 void parseSymbols();
183
184 /// Add a symbol which isn't defined just yet to a list to be resolved later.
185 void addPotentialUndefinedSymbol(ModuleSymbolTable::Symbol Sym,
186 bool isFunc);
187
188 /// Add a defined symbol to the list.
189 void addDefinedSymbol(StringRef Name, const GlobalValue *def,
190 bool isFunction);
191
192 /// Add a data symbol as defined to the list.
193 void addDefinedDataSymbol(ModuleSymbolTable::Symbol Sym);
194 void addDefinedDataSymbol(StringRef Name, const GlobalValue *v);
195
196 /// Add a function symbol as defined to the list.
197 void addDefinedFunctionSymbol(ModuleSymbolTable::Symbol Sym);
198 void addDefinedFunctionSymbol(StringRef Name, const Function *F);
199
200 /// Add a global symbol from module-level ASM to the defined list.
201 void addAsmGlobalSymbol(StringRef, lto_symbol_attributes scope);
202
203 /// Add a global symbol from module-level ASM to the undefined list.
204 void addAsmGlobalSymbolUndef(StringRef);
205
206 /// Parse i386/ppc ObjC class data structure.
207 void addObjCClass(const GlobalVariable *clgv);
208
209 /// Parse i386/ppc ObjC category data structure.
210 void addObjCCategory(const GlobalVariable *clgv);
211
212 /// Parse i386/ppc ObjC class list data structure.
213 void addObjCClassRef(const GlobalVariable *clgv);
214
215 /// Get string that the data pointer points to.
216 bool objcClassNameFromExpression(const Constant *c, std::string &name);
217
218 /// Create an LTOModule (private version).
219 static ErrorOr<std::unique_ptr<LTOModule>>
220 makeLTOModule(MemoryBufferRef Buffer, const TargetOptions &options,
221 LLVMContext &Context, bool ShouldBeLazy);
222};
223}
224#endif
225

source code of llvm/include/llvm/LTO/legacy/LTOModule.h