1 //===--- Bitcode/Writer/Writer.cpp - Bitcode Writer -----------------------===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file was developed by Chris Lattner and is distributed under 6 // the University of Illinois Open Source License. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 // 10 // Bitcode writer implementation. 11 // 12 //===----------------------------------------------------------------------===// 13 14 #include "llvm/Bitcode/ReaderWriter.h" 15 #include "llvm/Bitcode/BitstreamWriter.h" 16 #include "../LLVMBitCodes.h" 17 #include "ValueEnumerator.h" 18 #include "llvm/DerivedTypes.h" 19 #include "llvm/Module.h" 20 #include "llvm/TypeSymbolTable.h" 21 #include "llvm/Support/MathExtras.h" 22 using namespace llvm; 23 24 static const unsigned CurVersion = 0; 25 26 static void WriteStringRecord(unsigned Code, const std::string &Str, 27 unsigned AbbrevToUse, BitstreamWriter &Stream) { 28 SmallVector<unsigned, 64> Vals; 29 30 // Code: [strlen, strchar x N] 31 Vals.push_back(Str.size()); 32 for (unsigned i = 0, e = Str.size(); i != e; ++i) 33 Vals.push_back(Str[i]); 34 35 // Emit the finished record. 36 Stream.EmitRecord(Code, Vals, AbbrevToUse); 37 } 38 39 40 /// WriteTypeTable - Write out the type table for a module. 41 static void WriteTypeTable(const ValueEnumerator &VE, BitstreamWriter &Stream) { 42 const ValueEnumerator::TypeList &TypeList = VE.getTypes(); 43 44 Stream.EnterSubblock(bitc::TYPE_BLOCK_ID, 4 /*count from # abbrevs */); 45 SmallVector<uint64_t, 64> TypeVals; 46 47 // FIXME: Set up abbrevs now that we know the width of the type fields, etc. 48 49 // Emit an entry count so the reader can reserve space. 50 TypeVals.push_back(TypeList.size()); 51 Stream.EmitRecord(bitc::TYPE_CODE_NUMENTRY, TypeVals); 52 TypeVals.clear(); 53 54 // Loop over all of the types, emitting each in turn. 55 for (unsigned i = 0, e = TypeList.size(); i != e; ++i) { 56 const Type *T = TypeList[i].first; 57 int AbbrevToUse = 0; 58 unsigned Code = 0; 59 60 switch (T->getTypeID()) { 61 case Type::PackedStructTyID: // FIXME: Delete Type::PackedStructTyID. 62 default: assert(0 && "Unknown type!"); 63 case Type::VoidTyID: Code = bitc::TYPE_CODE_VOID; break; 64 case Type::FloatTyID: Code = bitc::TYPE_CODE_FLOAT; break; 65 case Type::DoubleTyID: Code = bitc::TYPE_CODE_DOUBLE; break; 66 case Type::LabelTyID: Code = bitc::TYPE_CODE_LABEL; break; 67 case Type::OpaqueTyID: Code = bitc::TYPE_CODE_OPAQUE; break; 68 case Type::IntegerTyID: 69 // INTEGER: [width] 70 Code = bitc::TYPE_CODE_INTEGER; 71 TypeVals.push_back(cast<IntegerType>(T)->getBitWidth()); 72 break; 73 case Type::PointerTyID: 74 // POINTER: [pointee type] 75 Code = bitc::TYPE_CODE_POINTER; 76 TypeVals.push_back(VE.getTypeID(cast<PointerType>(T)->getElementType())); 77 break; 78 79 case Type::FunctionTyID: { 80 const FunctionType *FT = cast<FunctionType>(T); 81 // FUNCTION: [isvararg, #pararms, paramty x N] 82 Code = bitc::TYPE_CODE_FUNCTION; 83 TypeVals.push_back(FT->isVarArg()); 84 TypeVals.push_back(VE.getTypeID(FT->getReturnType())); 85 // FIXME: PARAM ATTR ID! 86 TypeVals.push_back(FT->getNumParams()); 87 for (unsigned i = 0, e = FT->getNumParams(); i != e; ++i) 88 TypeVals.push_back(VE.getTypeID(FT->getParamType(i))); 89 break; 90 } 91 case Type::StructTyID: { 92 const StructType *ST = cast<StructType>(T); 93 // STRUCT: [ispacked, #elts, eltty x N] 94 Code = bitc::TYPE_CODE_STRUCT; 95 TypeVals.push_back(ST->isPacked()); 96 TypeVals.push_back(ST->getNumElements()); 97 // Output all of the element types... 98 for (StructType::element_iterator I = ST->element_begin(), 99 E = ST->element_end(); I != E; ++I) 100 TypeVals.push_back(VE.getTypeID(*I)); 101 break; 102 } 103 case Type::ArrayTyID: { 104 const ArrayType *AT = cast<ArrayType>(T); 105 // ARRAY: [numelts, eltty] 106 Code = bitc::TYPE_CODE_ARRAY; 107 TypeVals.push_back(AT->getNumElements()); 108 TypeVals.push_back(VE.getTypeID(AT->getElementType())); 109 break; 110 } 111 case Type::VectorTyID: { 112 const VectorType *VT = cast<VectorType>(T); 113 // VECTOR [numelts, eltty] 114 Code = bitc::TYPE_CODE_VECTOR; 115 TypeVals.push_back(VT->getNumElements()); 116 TypeVals.push_back(VE.getTypeID(VT->getElementType())); 117 break; 118 } 119 } 120 121 // Emit the finished record. 122 Stream.EmitRecord(Code, TypeVals, AbbrevToUse); 123 TypeVals.clear(); 124 } 125 126 Stream.ExitBlock(); 127 } 128 129 /// WriteTypeSymbolTable - Emit a block for the specified type symtab. 130 static void WriteTypeSymbolTable(const TypeSymbolTable &TST, 131 const ValueEnumerator &VE, 132 BitstreamWriter &Stream) { 133 if (TST.empty()) return; 134 135 Stream.EnterSubblock(bitc::TYPE_SYMTAB_BLOCK_ID, 3); 136 137 // FIXME: Set up the abbrev, we know how many types there are! 138 // FIXME: We know if the type names can use 7-bit ascii. 139 140 SmallVector<unsigned, 64> NameVals; 141 142 for (TypeSymbolTable::const_iterator TI = TST.begin(), TE = TST.end(); 143 TI != TE; ++TI) { 144 unsigned AbbrevToUse = 0; 145 146 // TST_ENTRY: [typeid, namelen, namechar x N] 147 NameVals.push_back(VE.getTypeID(TI->second)); 148 149 const std::string &Str = TI->first; 150 NameVals.push_back(Str.size()); 151 for (unsigned i = 0, e = Str.size(); i != e; ++i) 152 NameVals.push_back(Str[i]); 153 154 // Emit the finished record. 155 Stream.EmitRecord(bitc::TST_ENTRY_CODE, NameVals, AbbrevToUse); 156 NameVals.clear(); 157 } 158 159 Stream.ExitBlock(); 160 } 161 162 static unsigned getEncodedLinkage(const GlobalValue *GV) { 163 switch (GV->getLinkage()) { 164 default: assert(0 && "Invalid linkage!"); 165 case GlobalValue::ExternalLinkage: return 0; 166 case GlobalValue::WeakLinkage: return 1; 167 case GlobalValue::AppendingLinkage: return 2; 168 case GlobalValue::InternalLinkage: return 3; 169 case GlobalValue::LinkOnceLinkage: return 4; 170 case GlobalValue::DLLImportLinkage: return 5; 171 case GlobalValue::DLLExportLinkage: return 6; 172 case GlobalValue::ExternalWeakLinkage: return 7; 173 } 174 } 175 176 static unsigned getEncodedVisibility(const GlobalValue *GV) { 177 switch (GV->getVisibility()) { 178 default: assert(0 && "Invalid visibility!"); 179 case GlobalValue::DefaultVisibility: return 0; 180 case GlobalValue::HiddenVisibility: return 1; 181 } 182 } 183 184 // Emit top-level description of module, including target triple, inline asm, 185 // descriptors for global variables, and function prototype info. 186 static void WriteModuleInfo(const Module *M, const ValueEnumerator &VE, 187 BitstreamWriter &Stream) { 188 // Emit the list of dependent libraries for the Module. 189 for (Module::lib_iterator I = M->lib_begin(), E = M->lib_end(); I != E; ++I) 190 WriteStringRecord(bitc::MODULE_CODE_DEPLIB, *I, 0/*TODO*/, Stream); 191 192 // Emit various pieces of data attached to a module. 193 if (!M->getTargetTriple().empty()) 194 WriteStringRecord(bitc::MODULE_CODE_TRIPLE, M->getTargetTriple(), 195 0/*TODO*/, Stream); 196 if (!M->getDataLayout().empty()) 197 WriteStringRecord(bitc::MODULE_CODE_DATALAYOUT, M->getDataLayout(), 198 0/*TODO*/, Stream); 199 if (!M->getModuleInlineAsm().empty()) 200 WriteStringRecord(bitc::MODULE_CODE_ASM, M->getModuleInlineAsm(), 201 0/*TODO*/, Stream); 202 203 // Emit information about sections. 204 std::map<std::string, unsigned> SectionMap; 205 for (Module::const_global_iterator GV = M->global_begin(),E = M->global_end(); 206 GV != E; ++GV) { 207 if (!GV->hasSection()) continue; 208 // Give section names unique ID's. 209 unsigned &Entry = SectionMap[GV->getSection()]; 210 if (Entry != 0) continue; 211 WriteStringRecord(bitc::MODULE_CODE_SECTIONNAME, GV->getSection(), 212 0/*TODO*/, Stream); 213 Entry = SectionMap.size(); 214 } 215 for (Module::const_iterator F = M->begin(), E = M->end(); F != E; ++F) { 216 if (!F->hasSection()) continue; 217 // Give section names unique ID's. 218 unsigned &Entry = SectionMap[F->getSection()]; 219 if (Entry != 0) continue; 220 WriteStringRecord(bitc::MODULE_CODE_SECTIONNAME, F->getSection(), 221 0/*TODO*/, Stream); 222 Entry = SectionMap.size(); 223 } 224 225 // TODO: Emit abbrev, now that we know # sections. 226 227 // Emit the global variable information. 228 SmallVector<unsigned, 64> Vals; 229 for (Module::const_global_iterator GV = M->global_begin(),E = M->global_end(); 230 GV != E; ++GV) { 231 232 // GLOBALVAR: [type, isconst, initid, 233 // linkage, alignment, section, visibility, threadlocal] 234 Vals.push_back(VE.getTypeID(GV->getType())); 235 Vals.push_back(GV->isConstant()); 236 Vals.push_back(GV->isDeclaration() ? 0 : 237 (VE.getValueID(GV->getInitializer()) + 1)); 238 Vals.push_back(getEncodedLinkage(GV)); 239 Vals.push_back(Log2_32(GV->getAlignment())+1); 240 Vals.push_back(GV->hasSection() ? SectionMap[GV->getSection()] : 0); 241 Vals.push_back(getEncodedVisibility(GV)); 242 Vals.push_back(GV->isThreadLocal()); 243 244 unsigned AbbrevToUse = 0; 245 Stream.EmitRecord(bitc::MODULE_CODE_GLOBALVAR, Vals, AbbrevToUse); 246 Vals.clear(); 247 } 248 249 // Emit the function proto information. 250 for (Module::const_iterator F = M->begin(), E = M->end(); F != E; ++F) { 251 // FUNCTION: [type, callingconv, isproto, linkage, alignment, section, 252 // visibility] 253 Vals.push_back(VE.getTypeID(F->getType())); 254 Vals.push_back(F->getCallingConv()); 255 Vals.push_back(F->isDeclaration()); 256 Vals.push_back(getEncodedLinkage(F)); 257 Vals.push_back(Log2_32(F->getAlignment())+1); 258 Vals.push_back(F->hasSection() ? SectionMap[F->getSection()] : 0); 259 Vals.push_back(getEncodedVisibility(F)); 260 261 unsigned AbbrevToUse = 0; 262 Stream.EmitRecord(bitc::MODULE_CODE_FUNCTION, Vals, AbbrevToUse); 263 Vals.clear(); 264 } 265 } 266 267 268 /// WriteModule - Emit the specified module to the bitstream. 269 static void WriteModule(const Module *M, BitstreamWriter &Stream) { 270 Stream.EnterSubblock(bitc::MODULE_BLOCK_ID, 2); 271 272 // Emit the version number if it is non-zero. 273 if (CurVersion) { 274 SmallVector<unsigned, 1> VersionVals; 275 VersionVals.push_back(CurVersion); 276 Stream.EmitRecord(bitc::MODULE_CODE_VERSION, VersionVals); 277 } 278 279 // Analyze the module, enumerating globals, functions, etc. 280 ValueEnumerator VE(M); 281 282 // Emit information describing all of the types in the module. 283 WriteTypeTable(VE, Stream); 284 285 // FIXME: Emit constants. 286 287 // Emit top-level description of module, including target triple, inline asm, 288 // descriptors for global variables, and function prototype info. 289 WriteModuleInfo(M, VE, Stream); 290 291 // Emit the type symbol table information. 292 WriteTypeSymbolTable(M->getTypeSymbolTable(), VE, Stream); 293 Stream.ExitBlock(); 294 } 295 296 /// WriteBitcodeToFile - Write the specified module to the specified output 297 /// stream. 298 void llvm::WriteBitcodeToFile(const Module *M, std::ostream &Out) { 299 std::vector<unsigned char> Buffer; 300 BitstreamWriter Stream(Buffer); 301 302 Buffer.reserve(256*1024); 303 304 // Emit the file header. 305 Stream.Emit((unsigned)'B', 8); 306 Stream.Emit((unsigned)'C', 8); 307 Stream.Emit(0x0, 4); 308 Stream.Emit(0xC, 4); 309 Stream.Emit(0xE, 4); 310 Stream.Emit(0xD, 4); 311 312 // Emit the module. 313 WriteModule(M, Stream); 314 315 // Write the generated bitstream to "Out". 316 Out.write((char*)&Buffer.front(), Buffer.size()); 317 } 318