1 //===-LTOCodeGenerator.h - LLVM Link Time Optimizer -----------------------===// 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 // This file declares the LTOCodeGenerator class. 11 // 12 // LTO compilation consists of three phases: Pre-IPO, IPO and Post-IPO. 13 // 14 // The Pre-IPO phase compiles source code into bitcode file. The resulting 15 // bitcode files, along with object files and libraries, will be fed to the 16 // linker to through the IPO and Post-IPO phases. By using obj-file extension, 17 // the resulting bitcode file disguises itself as an object file, and therefore 18 // obviates the need of writing a special set of the make-rules only for LTO 19 // compilation. 20 // 21 // The IPO phase perform inter-procedural analyses and optimizations, and 22 // the Post-IPO consists two sub-phases: intra-procedural scalar optimizations 23 // (SOPT), and intra-procedural target-dependent code generator (CG). 24 // 25 // As of this writing, we don't separate IPO and the Post-IPO SOPT. They 26 // are intermingled together, and are driven by a single pass manager (see 27 // PassManagerBuilder::populateLTOPassManager()). 28 // 29 // The "LTOCodeGenerator" is the driver for the IPO and Post-IPO stages. 30 // The "CodeGenerator" here is bit confusing. Don't confuse the "CodeGenerator" 31 // with the machine specific code generator. 32 // 33 //===----------------------------------------------------------------------===// 34 35 #ifndef LLVM_LTO_LTOCODEGENERATOR_H 36 #define LLVM_LTO_LTOCODEGENERATOR_H 37 38 #include "llvm-c/lto.h" 39 #include "llvm/ADT/ArrayRef.h" 40 #include "llvm/ADT/SmallPtrSet.h" 41 #include "llvm/ADT/StringMap.h" 42 #include "llvm/Linker/Linker.h" 43 #include "llvm/Target/TargetOptions.h" 44 #include <string> 45 #include <vector> 46 47 namespace llvm { 48 class LLVMContext; 49 class DiagnosticInfo; 50 class GlobalValue; 51 class Mangler; 52 class MemoryBuffer; 53 class TargetLibraryInfo; 54 class TargetMachine; 55 class raw_ostream; 56 57 //===----------------------------------------------------------------------===// 58 /// C++ class which implements the opaque lto_code_gen_t type. 59 /// 60 struct LTOCodeGenerator { 61 static const char *getVersionString(); 62 63 LTOCodeGenerator(); 64 LTOCodeGenerator(std::unique_ptr<LLVMContext> Context); 65 ~LTOCodeGenerator(); 66 67 // Merge given module, return true on success. 68 bool addModule(struct LTOModule *); 69 70 void setTargetOptions(TargetOptions options); 71 void setDebugInfo(lto_debug_model); 72 void setCodePICModel(lto_codegen_model); 73 setCpuLTOCodeGenerator74 void setCpu(const char *mCpu) { MCpu = mCpu; } setAttrLTOCodeGenerator75 void setAttr(const char *mAttr) { MAttr = mAttr; } 76 addMustPreserveSymbolLTOCodeGenerator77 void addMustPreserveSymbol(const char *sym) { MustPreserveSymbols[sym] = 1; } 78 79 // To pass options to the driver and optimization passes. These options are 80 // not necessarily for debugging purpose (The function name is misleading). 81 // This function should be called before LTOCodeGenerator::compilexxx(), 82 // and LTOCodeGenerator::writeMergedModules(). 83 void setCodeGenDebugOptions(const char *opts); 84 85 // Parse the options set in setCodeGenDebugOptions. Like 86 // setCodeGenDebugOptions, this must be called before 87 // LTOCodeGenerator::compilexxx() and LTOCodeGenerator::writeMergedModules() 88 void parseCodeGenDebugOptions(); 89 90 // Write the merged module to the file specified by the given path. 91 // Return true on success. 92 bool writeMergedModules(const char *path, std::string &errMsg); 93 94 // Compile the merged module into a *single* object file; the path to object 95 // file is returned to the caller via argument "name". Return true on 96 // success. 97 // 98 // NOTE that it is up to the linker to remove the intermediate object file. 99 // Do not try to remove the object file in LTOCodeGenerator's destructor 100 // as we don't who (LTOCodeGenerator or the obj file) will last longer. 101 bool compile_to_file(const char **name, 102 bool disableOpt, 103 bool disableInline, 104 bool disableGVNLoadPRE, 105 bool disableVectorization, 106 std::string &errMsg); 107 108 // As with compile_to_file(), this function compiles the merged module into 109 // single object file. Instead of returning the object-file-path to the caller 110 // (linker), it brings the object to a buffer, and return the buffer to the 111 // caller. This function should delete intermediate object file once its content 112 // is brought to memory. Return NULL if the compilation was not successful. 113 const void *compile(size_t *length, 114 bool disableOpt, 115 bool disableInline, 116 bool disableGVNLoadPRE, 117 bool disableVectorization, 118 std::string &errMsg); 119 120 void setDiagnosticHandler(lto_diagnostic_handler_t, void *); 121 getContextLTOCodeGenerator122 LLVMContext &getContext() { return Context; } 123 124 private: 125 void initializeLTOPasses(); 126 127 bool generateObjectFile(raw_ostream &out, bool disableOpt, bool disableInline, 128 bool disableGVNLoadPRE, bool disableVectorization, 129 std::string &errMsg); 130 void applyScopeRestrictions(); 131 void applyRestriction(GlobalValue &GV, ArrayRef<StringRef> Libcalls, 132 std::vector<const char *> &MustPreserveList, 133 SmallPtrSetImpl<GlobalValue *> &AsmUsed, 134 Mangler &Mangler); 135 bool determineTarget(std::string &errMsg); 136 137 static void DiagnosticHandler(const DiagnosticInfo &DI, void *Context); 138 139 void DiagnosticHandler2(const DiagnosticInfo &DI); 140 141 typedef StringMap<uint8_t> StringSet; 142 143 void initialize(); 144 std::unique_ptr<LLVMContext> OwnedContext; 145 LLVMContext &Context; 146 Linker IRLinker; 147 TargetMachine *TargetMach; 148 bool EmitDwarfDebugInfo; 149 bool ScopeRestrictionsDone; 150 lto_codegen_model CodeModel; 151 StringSet MustPreserveSymbols; 152 StringSet AsmUndefinedRefs; 153 std::unique_ptr<MemoryBuffer> NativeObjectFile; 154 std::vector<char *> CodegenOptions; 155 std::string MCpu; 156 std::string MAttr; 157 std::string NativeObjectPath; 158 TargetOptions Options; 159 lto_diagnostic_handler_t DiagHandler; 160 void *DiagContext; 161 }; 162 } 163 #endif 164