CGCall.cpp revision 288943
1//===--- CGCall.cpp - Encapsulate calling convention details --------------===// 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// These classes wrap the information about a call or function 11// definition used to handle ABI compliancy. 12// 13//===----------------------------------------------------------------------===// 14 15#include "CGCall.h" 16#include "ABIInfo.h" 17#include "CGCXXABI.h" 18#include "CodeGenFunction.h" 19#include "CodeGenModule.h" 20#include "TargetInfo.h" 21#include "clang/AST/Decl.h" 22#include "clang/AST/DeclCXX.h" 23#include "clang/AST/DeclObjC.h" 24#include "clang/Basic/TargetInfo.h" 25#include "clang/CodeGen/CGFunctionInfo.h" 26#include "clang/Frontend/CodeGenOptions.h" 27#include "llvm/ADT/StringExtras.h" 28#include "llvm/IR/Attributes.h" 29#include "llvm/IR/CallSite.h" 30#include "llvm/IR/DataLayout.h" 31#include "llvm/IR/InlineAsm.h" 32#include "llvm/IR/Intrinsics.h" 33#include "llvm/IR/IntrinsicInst.h" 34#include "llvm/Transforms/Utils/Local.h" 35using namespace clang; 36using namespace CodeGen; 37 38/***/ 39 40static unsigned ClangCallConvToLLVMCallConv(CallingConv CC) { 41 switch (CC) { 42 default: return llvm::CallingConv::C; 43 case CC_X86StdCall: return llvm::CallingConv::X86_StdCall; 44 case CC_X86FastCall: return llvm::CallingConv::X86_FastCall; 45 case CC_X86ThisCall: return llvm::CallingConv::X86_ThisCall; 46 case CC_X86_64Win64: return llvm::CallingConv::X86_64_Win64; 47 case CC_X86_64SysV: return llvm::CallingConv::X86_64_SysV; 48 case CC_AAPCS: return llvm::CallingConv::ARM_AAPCS; 49 case CC_AAPCS_VFP: return llvm::CallingConv::ARM_AAPCS_VFP; 50 case CC_IntelOclBicc: return llvm::CallingConv::Intel_OCL_BI; 51 // TODO: Add support for __pascal to LLVM. 52 case CC_X86Pascal: return llvm::CallingConv::C; 53 // TODO: Add support for __vectorcall to LLVM. 54 case CC_X86VectorCall: return llvm::CallingConv::X86_VectorCall; 55 case CC_SpirFunction: return llvm::CallingConv::SPIR_FUNC; 56 case CC_SpirKernel: return llvm::CallingConv::SPIR_KERNEL; 57 } 58} 59 60/// Derives the 'this' type for codegen purposes, i.e. ignoring method 61/// qualification. 62/// FIXME: address space qualification? 63static CanQualType GetThisType(ASTContext &Context, const CXXRecordDecl *RD) { 64 QualType RecTy = Context.getTagDeclType(RD)->getCanonicalTypeInternal(); 65 return Context.getPointerType(CanQualType::CreateUnsafe(RecTy)); 66} 67 68/// Returns the canonical formal type of the given C++ method. 69static CanQual<FunctionProtoType> GetFormalType(const CXXMethodDecl *MD) { 70 return MD->getType()->getCanonicalTypeUnqualified() 71 .getAs<FunctionProtoType>(); 72} 73 74/// Returns the "extra-canonicalized" return type, which discards 75/// qualifiers on the return type. Codegen doesn't care about them, 76/// and it makes ABI code a little easier to be able to assume that 77/// all parameter and return types are top-level unqualified. 78static CanQualType GetReturnType(QualType RetTy) { 79 return RetTy->getCanonicalTypeUnqualified().getUnqualifiedType(); 80} 81 82/// Arrange the argument and result information for a value of the given 83/// unprototyped freestanding function type. 84const CGFunctionInfo & 85CodeGenTypes::arrangeFreeFunctionType(CanQual<FunctionNoProtoType> FTNP) { 86 // When translating an unprototyped function type, always use a 87 // variadic type. 88 return arrangeLLVMFunctionInfo(FTNP->getReturnType().getUnqualifiedType(), 89 /*instanceMethod=*/false, 90 /*chainCall=*/false, None, 91 FTNP->getExtInfo(), RequiredArgs(0)); 92} 93 94/// Arrange the LLVM function layout for a value of the given function 95/// type, on top of any implicit parameters already stored. 96static const CGFunctionInfo & 97arrangeLLVMFunctionInfo(CodeGenTypes &CGT, bool instanceMethod, 98 SmallVectorImpl<CanQualType> &prefix, 99 CanQual<FunctionProtoType> FTP) { 100 RequiredArgs required = RequiredArgs::forPrototypePlus(FTP, prefix.size()); 101 // FIXME: Kill copy. 102 prefix.append(FTP->param_type_begin(), FTP->param_type_end()); 103 CanQualType resultType = FTP->getReturnType().getUnqualifiedType(); 104 return CGT.arrangeLLVMFunctionInfo(resultType, instanceMethod, 105 /*chainCall=*/false, prefix, 106 FTP->getExtInfo(), required); 107} 108 109/// Arrange the argument and result information for a value of the 110/// given freestanding function type. 111const CGFunctionInfo & 112CodeGenTypes::arrangeFreeFunctionType(CanQual<FunctionProtoType> FTP) { 113 SmallVector<CanQualType, 16> argTypes; 114 return ::arrangeLLVMFunctionInfo(*this, /*instanceMethod=*/false, argTypes, 115 FTP); 116} 117 118static CallingConv getCallingConventionForDecl(const Decl *D, bool IsWindows) { 119 // Set the appropriate calling convention for the Function. 120 if (D->hasAttr<StdCallAttr>()) 121 return CC_X86StdCall; 122 123 if (D->hasAttr<FastCallAttr>()) 124 return CC_X86FastCall; 125 126 if (D->hasAttr<ThisCallAttr>()) 127 return CC_X86ThisCall; 128 129 if (D->hasAttr<VectorCallAttr>()) 130 return CC_X86VectorCall; 131 132 if (D->hasAttr<PascalAttr>()) 133 return CC_X86Pascal; 134 135 if (PcsAttr *PCS = D->getAttr<PcsAttr>()) 136 return (PCS->getPCS() == PcsAttr::AAPCS ? CC_AAPCS : CC_AAPCS_VFP); 137 138 if (D->hasAttr<IntelOclBiccAttr>()) 139 return CC_IntelOclBicc; 140 141 if (D->hasAttr<MSABIAttr>()) 142 return IsWindows ? CC_C : CC_X86_64Win64; 143 144 if (D->hasAttr<SysVABIAttr>()) 145 return IsWindows ? CC_X86_64SysV : CC_C; 146 147 return CC_C; 148} 149 150/// Arrange the argument and result information for a call to an 151/// unknown C++ non-static member function of the given abstract type. 152/// (Zero value of RD means we don't have any meaningful "this" argument type, 153/// so fall back to a generic pointer type). 154/// The member function must be an ordinary function, i.e. not a 155/// constructor or destructor. 156const CGFunctionInfo & 157CodeGenTypes::arrangeCXXMethodType(const CXXRecordDecl *RD, 158 const FunctionProtoType *FTP) { 159 SmallVector<CanQualType, 16> argTypes; 160 161 // Add the 'this' pointer. 162 if (RD) 163 argTypes.push_back(GetThisType(Context, RD)); 164 else 165 argTypes.push_back(Context.VoidPtrTy); 166 167 return ::arrangeLLVMFunctionInfo( 168 *this, true, argTypes, 169 FTP->getCanonicalTypeUnqualified().getAs<FunctionProtoType>()); 170} 171 172/// Arrange the argument and result information for a declaration or 173/// definition of the given C++ non-static member function. The 174/// member function must be an ordinary function, i.e. not a 175/// constructor or destructor. 176const CGFunctionInfo & 177CodeGenTypes::arrangeCXXMethodDeclaration(const CXXMethodDecl *MD) { 178 assert(!isa<CXXConstructorDecl>(MD) && "wrong method for constructors!"); 179 assert(!isa<CXXDestructorDecl>(MD) && "wrong method for destructors!"); 180 181 CanQual<FunctionProtoType> prototype = GetFormalType(MD); 182 183 if (MD->isInstance()) { 184 // The abstract case is perfectly fine. 185 const CXXRecordDecl *ThisType = TheCXXABI.getThisArgumentTypeForMethod(MD); 186 return arrangeCXXMethodType(ThisType, prototype.getTypePtr()); 187 } 188 189 return arrangeFreeFunctionType(prototype); 190} 191 192const CGFunctionInfo & 193CodeGenTypes::arrangeCXXStructorDeclaration(const CXXMethodDecl *MD, 194 StructorType Type) { 195 196 SmallVector<CanQualType, 16> argTypes; 197 argTypes.push_back(GetThisType(Context, MD->getParent())); 198 199 GlobalDecl GD; 200 if (auto *CD = dyn_cast<CXXConstructorDecl>(MD)) { 201 GD = GlobalDecl(CD, toCXXCtorType(Type)); 202 } else { 203 auto *DD = dyn_cast<CXXDestructorDecl>(MD); 204 GD = GlobalDecl(DD, toCXXDtorType(Type)); 205 } 206 207 CanQual<FunctionProtoType> FTP = GetFormalType(MD); 208 209 // Add the formal parameters. 210 argTypes.append(FTP->param_type_begin(), FTP->param_type_end()); 211 212 TheCXXABI.buildStructorSignature(MD, Type, argTypes); 213 214 RequiredArgs required = 215 (MD->isVariadic() ? RequiredArgs(argTypes.size()) : RequiredArgs::All); 216 217 FunctionType::ExtInfo extInfo = FTP->getExtInfo(); 218 CanQualType resultType = TheCXXABI.HasThisReturn(GD) 219 ? argTypes.front() 220 : TheCXXABI.hasMostDerivedReturn(GD) 221 ? CGM.getContext().VoidPtrTy 222 : Context.VoidTy; 223 return arrangeLLVMFunctionInfo(resultType, /*instanceMethod=*/true, 224 /*chainCall=*/false, argTypes, extInfo, 225 required); 226} 227 228/// Arrange a call to a C++ method, passing the given arguments. 229const CGFunctionInfo & 230CodeGenTypes::arrangeCXXConstructorCall(const CallArgList &args, 231 const CXXConstructorDecl *D, 232 CXXCtorType CtorKind, 233 unsigned ExtraArgs) { 234 // FIXME: Kill copy. 235 SmallVector<CanQualType, 16> ArgTypes; 236 for (const auto &Arg : args) 237 ArgTypes.push_back(Context.getCanonicalParamType(Arg.Ty)); 238 239 CanQual<FunctionProtoType> FPT = GetFormalType(D); 240 RequiredArgs Required = RequiredArgs::forPrototypePlus(FPT, 1 + ExtraArgs); 241 GlobalDecl GD(D, CtorKind); 242 CanQualType ResultType = TheCXXABI.HasThisReturn(GD) 243 ? ArgTypes.front() 244 : TheCXXABI.hasMostDerivedReturn(GD) 245 ? CGM.getContext().VoidPtrTy 246 : Context.VoidTy; 247 248 FunctionType::ExtInfo Info = FPT->getExtInfo(); 249 return arrangeLLVMFunctionInfo(ResultType, /*instanceMethod=*/true, 250 /*chainCall=*/false, ArgTypes, Info, 251 Required); 252} 253 254/// Arrange the argument and result information for the declaration or 255/// definition of the given function. 256const CGFunctionInfo & 257CodeGenTypes::arrangeFunctionDeclaration(const FunctionDecl *FD) { 258 if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(FD)) 259 if (MD->isInstance()) 260 return arrangeCXXMethodDeclaration(MD); 261 262 CanQualType FTy = FD->getType()->getCanonicalTypeUnqualified(); 263 264 assert(isa<FunctionType>(FTy)); 265 266 // When declaring a function without a prototype, always use a 267 // non-variadic type. 268 if (isa<FunctionNoProtoType>(FTy)) { 269 CanQual<FunctionNoProtoType> noProto = FTy.getAs<FunctionNoProtoType>(); 270 return arrangeLLVMFunctionInfo( 271 noProto->getReturnType(), /*instanceMethod=*/false, 272 /*chainCall=*/false, None, noProto->getExtInfo(), RequiredArgs::All); 273 } 274 275 assert(isa<FunctionProtoType>(FTy)); 276 return arrangeFreeFunctionType(FTy.getAs<FunctionProtoType>()); 277} 278 279/// Arrange the argument and result information for the declaration or 280/// definition of an Objective-C method. 281const CGFunctionInfo & 282CodeGenTypes::arrangeObjCMethodDeclaration(const ObjCMethodDecl *MD) { 283 // It happens that this is the same as a call with no optional 284 // arguments, except also using the formal 'self' type. 285 return arrangeObjCMessageSendSignature(MD, MD->getSelfDecl()->getType()); 286} 287 288/// Arrange the argument and result information for the function type 289/// through which to perform a send to the given Objective-C method, 290/// using the given receiver type. The receiver type is not always 291/// the 'self' type of the method or even an Objective-C pointer type. 292/// This is *not* the right method for actually performing such a 293/// message send, due to the possibility of optional arguments. 294const CGFunctionInfo & 295CodeGenTypes::arrangeObjCMessageSendSignature(const ObjCMethodDecl *MD, 296 QualType receiverType) { 297 SmallVector<CanQualType, 16> argTys; 298 argTys.push_back(Context.getCanonicalParamType(receiverType)); 299 argTys.push_back(Context.getCanonicalParamType(Context.getObjCSelType())); 300 // FIXME: Kill copy? 301 for (const auto *I : MD->params()) { 302 argTys.push_back(Context.getCanonicalParamType(I->getType())); 303 } 304 305 FunctionType::ExtInfo einfo; 306 bool IsWindows = getContext().getTargetInfo().getTriple().isOSWindows(); 307 einfo = einfo.withCallingConv(getCallingConventionForDecl(MD, IsWindows)); 308 309 if (getContext().getLangOpts().ObjCAutoRefCount && 310 MD->hasAttr<NSReturnsRetainedAttr>()) 311 einfo = einfo.withProducesResult(true); 312 313 RequiredArgs required = 314 (MD->isVariadic() ? RequiredArgs(argTys.size()) : RequiredArgs::All); 315 316 return arrangeLLVMFunctionInfo( 317 GetReturnType(MD->getReturnType()), /*instanceMethod=*/false, 318 /*chainCall=*/false, argTys, einfo, required); 319} 320 321const CGFunctionInfo & 322CodeGenTypes::arrangeGlobalDeclaration(GlobalDecl GD) { 323 // FIXME: Do we need to handle ObjCMethodDecl? 324 const FunctionDecl *FD = cast<FunctionDecl>(GD.getDecl()); 325 326 if (const CXXConstructorDecl *CD = dyn_cast<CXXConstructorDecl>(FD)) 327 return arrangeCXXStructorDeclaration(CD, getFromCtorType(GD.getCtorType())); 328 329 if (const CXXDestructorDecl *DD = dyn_cast<CXXDestructorDecl>(FD)) 330 return arrangeCXXStructorDeclaration(DD, getFromDtorType(GD.getDtorType())); 331 332 return arrangeFunctionDeclaration(FD); 333} 334 335/// Arrange a thunk that takes 'this' as the first parameter followed by 336/// varargs. Return a void pointer, regardless of the actual return type. 337/// The body of the thunk will end in a musttail call to a function of the 338/// correct type, and the caller will bitcast the function to the correct 339/// prototype. 340const CGFunctionInfo & 341CodeGenTypes::arrangeMSMemberPointerThunk(const CXXMethodDecl *MD) { 342 assert(MD->isVirtual() && "only virtual memptrs have thunks"); 343 CanQual<FunctionProtoType> FTP = GetFormalType(MD); 344 CanQualType ArgTys[] = { GetThisType(Context, MD->getParent()) }; 345 return arrangeLLVMFunctionInfo(Context.VoidTy, /*instanceMethod=*/false, 346 /*chainCall=*/false, ArgTys, 347 FTP->getExtInfo(), RequiredArgs(1)); 348} 349 350const CGFunctionInfo & 351CodeGenTypes::arrangeMSCtorClosure(const CXXConstructorDecl *CD, 352 CXXCtorType CT) { 353 assert(CT == Ctor_CopyingClosure || CT == Ctor_DefaultClosure); 354 355 CanQual<FunctionProtoType> FTP = GetFormalType(CD); 356 SmallVector<CanQualType, 2> ArgTys; 357 const CXXRecordDecl *RD = CD->getParent(); 358 ArgTys.push_back(GetThisType(Context, RD)); 359 if (CT == Ctor_CopyingClosure) 360 ArgTys.push_back(*FTP->param_type_begin()); 361 if (RD->getNumVBases() > 0) 362 ArgTys.push_back(Context.IntTy); 363 CallingConv CC = Context.getDefaultCallingConvention( 364 /*IsVariadic=*/false, /*IsCXXMethod=*/true); 365 return arrangeLLVMFunctionInfo(Context.VoidTy, /*instanceMethod=*/true, 366 /*chainCall=*/false, ArgTys, 367 FunctionType::ExtInfo(CC), RequiredArgs::All); 368} 369 370/// Arrange a call as unto a free function, except possibly with an 371/// additional number of formal parameters considered required. 372static const CGFunctionInfo & 373arrangeFreeFunctionLikeCall(CodeGenTypes &CGT, 374 CodeGenModule &CGM, 375 const CallArgList &args, 376 const FunctionType *fnType, 377 unsigned numExtraRequiredArgs, 378 bool chainCall) { 379 assert(args.size() >= numExtraRequiredArgs); 380 381 // In most cases, there are no optional arguments. 382 RequiredArgs required = RequiredArgs::All; 383 384 // If we have a variadic prototype, the required arguments are the 385 // extra prefix plus the arguments in the prototype. 386 if (const FunctionProtoType *proto = dyn_cast<FunctionProtoType>(fnType)) { 387 if (proto->isVariadic()) 388 required = RequiredArgs(proto->getNumParams() + numExtraRequiredArgs); 389 390 // If we don't have a prototype at all, but we're supposed to 391 // explicitly use the variadic convention for unprototyped calls, 392 // treat all of the arguments as required but preserve the nominal 393 // possibility of variadics. 394 } else if (CGM.getTargetCodeGenInfo() 395 .isNoProtoCallVariadic(args, 396 cast<FunctionNoProtoType>(fnType))) { 397 required = RequiredArgs(args.size()); 398 } 399 400 // FIXME: Kill copy. 401 SmallVector<CanQualType, 16> argTypes; 402 for (const auto &arg : args) 403 argTypes.push_back(CGT.getContext().getCanonicalParamType(arg.Ty)); 404 return CGT.arrangeLLVMFunctionInfo(GetReturnType(fnType->getReturnType()), 405 /*instanceMethod=*/false, chainCall, 406 argTypes, fnType->getExtInfo(), required); 407} 408 409/// Figure out the rules for calling a function with the given formal 410/// type using the given arguments. The arguments are necessary 411/// because the function might be unprototyped, in which case it's 412/// target-dependent in crazy ways. 413const CGFunctionInfo & 414CodeGenTypes::arrangeFreeFunctionCall(const CallArgList &args, 415 const FunctionType *fnType, 416 bool chainCall) { 417 return arrangeFreeFunctionLikeCall(*this, CGM, args, fnType, 418 chainCall ? 1 : 0, chainCall); 419} 420 421/// A block function call is essentially a free-function call with an 422/// extra implicit argument. 423const CGFunctionInfo & 424CodeGenTypes::arrangeBlockFunctionCall(const CallArgList &args, 425 const FunctionType *fnType) { 426 return arrangeFreeFunctionLikeCall(*this, CGM, args, fnType, 1, 427 /*chainCall=*/false); 428} 429 430const CGFunctionInfo & 431CodeGenTypes::arrangeFreeFunctionCall(QualType resultType, 432 const CallArgList &args, 433 FunctionType::ExtInfo info, 434 RequiredArgs required) { 435 // FIXME: Kill copy. 436 SmallVector<CanQualType, 16> argTypes; 437 for (const auto &Arg : args) 438 argTypes.push_back(Context.getCanonicalParamType(Arg.Ty)); 439 return arrangeLLVMFunctionInfo( 440 GetReturnType(resultType), /*instanceMethod=*/false, 441 /*chainCall=*/false, argTypes, info, required); 442} 443 444/// Arrange a call to a C++ method, passing the given arguments. 445const CGFunctionInfo & 446CodeGenTypes::arrangeCXXMethodCall(const CallArgList &args, 447 const FunctionProtoType *FPT, 448 RequiredArgs required) { 449 // FIXME: Kill copy. 450 SmallVector<CanQualType, 16> argTypes; 451 for (const auto &Arg : args) 452 argTypes.push_back(Context.getCanonicalParamType(Arg.Ty)); 453 454 FunctionType::ExtInfo info = FPT->getExtInfo(); 455 return arrangeLLVMFunctionInfo( 456 GetReturnType(FPT->getReturnType()), /*instanceMethod=*/true, 457 /*chainCall=*/false, argTypes, info, required); 458} 459 460const CGFunctionInfo &CodeGenTypes::arrangeFreeFunctionDeclaration( 461 QualType resultType, const FunctionArgList &args, 462 const FunctionType::ExtInfo &info, bool isVariadic) { 463 // FIXME: Kill copy. 464 SmallVector<CanQualType, 16> argTypes; 465 for (auto Arg : args) 466 argTypes.push_back(Context.getCanonicalParamType(Arg->getType())); 467 468 RequiredArgs required = 469 (isVariadic ? RequiredArgs(args.size()) : RequiredArgs::All); 470 return arrangeLLVMFunctionInfo( 471 GetReturnType(resultType), /*instanceMethod=*/false, 472 /*chainCall=*/false, argTypes, info, required); 473} 474 475const CGFunctionInfo &CodeGenTypes::arrangeNullaryFunction() { 476 return arrangeLLVMFunctionInfo( 477 getContext().VoidTy, /*instanceMethod=*/false, /*chainCall=*/false, 478 None, FunctionType::ExtInfo(), RequiredArgs::All); 479} 480 481/// Arrange the argument and result information for an abstract value 482/// of a given function type. This is the method which all of the 483/// above functions ultimately defer to. 484const CGFunctionInfo & 485CodeGenTypes::arrangeLLVMFunctionInfo(CanQualType resultType, 486 bool instanceMethod, 487 bool chainCall, 488 ArrayRef<CanQualType> argTypes, 489 FunctionType::ExtInfo info, 490 RequiredArgs required) { 491 assert(std::all_of(argTypes.begin(), argTypes.end(), 492 std::mem_fun_ref(&CanQualType::isCanonicalAsParam))); 493 494 unsigned CC = ClangCallConvToLLVMCallConv(info.getCC()); 495 496 // Lookup or create unique function info. 497 llvm::FoldingSetNodeID ID; 498 CGFunctionInfo::Profile(ID, instanceMethod, chainCall, info, required, 499 resultType, argTypes); 500 501 void *insertPos = nullptr; 502 CGFunctionInfo *FI = FunctionInfos.FindNodeOrInsertPos(ID, insertPos); 503 if (FI) 504 return *FI; 505 506 // Construct the function info. We co-allocate the ArgInfos. 507 FI = CGFunctionInfo::create(CC, instanceMethod, chainCall, info, 508 resultType, argTypes, required); 509 FunctionInfos.InsertNode(FI, insertPos); 510 511 bool inserted = FunctionsBeingProcessed.insert(FI).second; 512 (void)inserted; 513 assert(inserted && "Recursively being processed?"); 514 515 // Compute ABI information. 516 getABIInfo().computeInfo(*FI); 517 518 // Loop over all of the computed argument and return value info. If any of 519 // them are direct or extend without a specified coerce type, specify the 520 // default now. 521 ABIArgInfo &retInfo = FI->getReturnInfo(); 522 if (retInfo.canHaveCoerceToType() && retInfo.getCoerceToType() == nullptr) 523 retInfo.setCoerceToType(ConvertType(FI->getReturnType())); 524 525 for (auto &I : FI->arguments()) 526 if (I.info.canHaveCoerceToType() && I.info.getCoerceToType() == nullptr) 527 I.info.setCoerceToType(ConvertType(I.type)); 528 529 bool erased = FunctionsBeingProcessed.erase(FI); (void)erased; 530 assert(erased && "Not in set?"); 531 532 return *FI; 533} 534 535CGFunctionInfo *CGFunctionInfo::create(unsigned llvmCC, 536 bool instanceMethod, 537 bool chainCall, 538 const FunctionType::ExtInfo &info, 539 CanQualType resultType, 540 ArrayRef<CanQualType> argTypes, 541 RequiredArgs required) { 542 void *buffer = operator new(sizeof(CGFunctionInfo) + 543 sizeof(ArgInfo) * (argTypes.size() + 1)); 544 CGFunctionInfo *FI = new(buffer) CGFunctionInfo(); 545 FI->CallingConvention = llvmCC; 546 FI->EffectiveCallingConvention = llvmCC; 547 FI->ASTCallingConvention = info.getCC(); 548 FI->InstanceMethod = instanceMethod; 549 FI->ChainCall = chainCall; 550 FI->NoReturn = info.getNoReturn(); 551 FI->ReturnsRetained = info.getProducesResult(); 552 FI->Required = required; 553 FI->HasRegParm = info.getHasRegParm(); 554 FI->RegParm = info.getRegParm(); 555 FI->ArgStruct = nullptr; 556 FI->NumArgs = argTypes.size(); 557 FI->getArgsBuffer()[0].type = resultType; 558 for (unsigned i = 0, e = argTypes.size(); i != e; ++i) 559 FI->getArgsBuffer()[i + 1].type = argTypes[i]; 560 return FI; 561} 562 563/***/ 564 565namespace { 566// ABIArgInfo::Expand implementation. 567 568// Specifies the way QualType passed as ABIArgInfo::Expand is expanded. 569struct TypeExpansion { 570 enum TypeExpansionKind { 571 // Elements of constant arrays are expanded recursively. 572 TEK_ConstantArray, 573 // Record fields are expanded recursively (but if record is a union, only 574 // the field with the largest size is expanded). 575 TEK_Record, 576 // For complex types, real and imaginary parts are expanded recursively. 577 TEK_Complex, 578 // All other types are not expandable. 579 TEK_None 580 }; 581 582 const TypeExpansionKind Kind; 583 584 TypeExpansion(TypeExpansionKind K) : Kind(K) {} 585 virtual ~TypeExpansion() {} 586}; 587 588struct ConstantArrayExpansion : TypeExpansion { 589 QualType EltTy; 590 uint64_t NumElts; 591 592 ConstantArrayExpansion(QualType EltTy, uint64_t NumElts) 593 : TypeExpansion(TEK_ConstantArray), EltTy(EltTy), NumElts(NumElts) {} 594 static bool classof(const TypeExpansion *TE) { 595 return TE->Kind == TEK_ConstantArray; 596 } 597}; 598 599struct RecordExpansion : TypeExpansion { 600 SmallVector<const CXXBaseSpecifier *, 1> Bases; 601 602 SmallVector<const FieldDecl *, 1> Fields; 603 604 RecordExpansion(SmallVector<const CXXBaseSpecifier *, 1> &&Bases, 605 SmallVector<const FieldDecl *, 1> &&Fields) 606 : TypeExpansion(TEK_Record), Bases(Bases), Fields(Fields) {} 607 static bool classof(const TypeExpansion *TE) { 608 return TE->Kind == TEK_Record; 609 } 610}; 611 612struct ComplexExpansion : TypeExpansion { 613 QualType EltTy; 614 615 ComplexExpansion(QualType EltTy) : TypeExpansion(TEK_Complex), EltTy(EltTy) {} 616 static bool classof(const TypeExpansion *TE) { 617 return TE->Kind == TEK_Complex; 618 } 619}; 620 621struct NoExpansion : TypeExpansion { 622 NoExpansion() : TypeExpansion(TEK_None) {} 623 static bool classof(const TypeExpansion *TE) { 624 return TE->Kind == TEK_None; 625 } 626}; 627} // namespace 628 629static std::unique_ptr<TypeExpansion> 630getTypeExpansion(QualType Ty, const ASTContext &Context) { 631 if (const ConstantArrayType *AT = Context.getAsConstantArrayType(Ty)) { 632 return llvm::make_unique<ConstantArrayExpansion>( 633 AT->getElementType(), AT->getSize().getZExtValue()); 634 } 635 if (const RecordType *RT = Ty->getAs<RecordType>()) { 636 SmallVector<const CXXBaseSpecifier *, 1> Bases; 637 SmallVector<const FieldDecl *, 1> Fields; 638 const RecordDecl *RD = RT->getDecl(); 639 assert(!RD->hasFlexibleArrayMember() && 640 "Cannot expand structure with flexible array."); 641 if (RD->isUnion()) { 642 // Unions can be here only in degenerative cases - all the fields are same 643 // after flattening. Thus we have to use the "largest" field. 644 const FieldDecl *LargestFD = nullptr; 645 CharUnits UnionSize = CharUnits::Zero(); 646 647 for (const auto *FD : RD->fields()) { 648 // Skip zero length bitfields. 649 if (FD->isBitField() && FD->getBitWidthValue(Context) == 0) 650 continue; 651 assert(!FD->isBitField() && 652 "Cannot expand structure with bit-field members."); 653 CharUnits FieldSize = Context.getTypeSizeInChars(FD->getType()); 654 if (UnionSize < FieldSize) { 655 UnionSize = FieldSize; 656 LargestFD = FD; 657 } 658 } 659 if (LargestFD) 660 Fields.push_back(LargestFD); 661 } else { 662 if (const auto *CXXRD = dyn_cast<CXXRecordDecl>(RD)) { 663 assert(!CXXRD->isDynamicClass() && 664 "cannot expand vtable pointers in dynamic classes"); 665 for (const CXXBaseSpecifier &BS : CXXRD->bases()) 666 Bases.push_back(&BS); 667 } 668 669 for (const auto *FD : RD->fields()) { 670 // Skip zero length bitfields. 671 if (FD->isBitField() && FD->getBitWidthValue(Context) == 0) 672 continue; 673 assert(!FD->isBitField() && 674 "Cannot expand structure with bit-field members."); 675 Fields.push_back(FD); 676 } 677 } 678 return llvm::make_unique<RecordExpansion>(std::move(Bases), 679 std::move(Fields)); 680 } 681 if (const ComplexType *CT = Ty->getAs<ComplexType>()) { 682 return llvm::make_unique<ComplexExpansion>(CT->getElementType()); 683 } 684 return llvm::make_unique<NoExpansion>(); 685} 686 687static int getExpansionSize(QualType Ty, const ASTContext &Context) { 688 auto Exp = getTypeExpansion(Ty, Context); 689 if (auto CAExp = dyn_cast<ConstantArrayExpansion>(Exp.get())) { 690 return CAExp->NumElts * getExpansionSize(CAExp->EltTy, Context); 691 } 692 if (auto RExp = dyn_cast<RecordExpansion>(Exp.get())) { 693 int Res = 0; 694 for (auto BS : RExp->Bases) 695 Res += getExpansionSize(BS->getType(), Context); 696 for (auto FD : RExp->Fields) 697 Res += getExpansionSize(FD->getType(), Context); 698 return Res; 699 } 700 if (isa<ComplexExpansion>(Exp.get())) 701 return 2; 702 assert(isa<NoExpansion>(Exp.get())); 703 return 1; 704} 705 706void 707CodeGenTypes::getExpandedTypes(QualType Ty, 708 SmallVectorImpl<llvm::Type *>::iterator &TI) { 709 auto Exp = getTypeExpansion(Ty, Context); 710 if (auto CAExp = dyn_cast<ConstantArrayExpansion>(Exp.get())) { 711 for (int i = 0, n = CAExp->NumElts; i < n; i++) { 712 getExpandedTypes(CAExp->EltTy, TI); 713 } 714 } else if (auto RExp = dyn_cast<RecordExpansion>(Exp.get())) { 715 for (auto BS : RExp->Bases) 716 getExpandedTypes(BS->getType(), TI); 717 for (auto FD : RExp->Fields) 718 getExpandedTypes(FD->getType(), TI); 719 } else if (auto CExp = dyn_cast<ComplexExpansion>(Exp.get())) { 720 llvm::Type *EltTy = ConvertType(CExp->EltTy); 721 *TI++ = EltTy; 722 *TI++ = EltTy; 723 } else { 724 assert(isa<NoExpansion>(Exp.get())); 725 *TI++ = ConvertType(Ty); 726 } 727} 728 729void CodeGenFunction::ExpandTypeFromArgs( 730 QualType Ty, LValue LV, SmallVectorImpl<llvm::Argument *>::iterator &AI) { 731 assert(LV.isSimple() && 732 "Unexpected non-simple lvalue during struct expansion."); 733 734 auto Exp = getTypeExpansion(Ty, getContext()); 735 if (auto CAExp = dyn_cast<ConstantArrayExpansion>(Exp.get())) { 736 for (int i = 0, n = CAExp->NumElts; i < n; i++) { 737 llvm::Value *EltAddr = 738 Builder.CreateConstGEP2_32(nullptr, LV.getAddress(), 0, i); 739 LValue LV = MakeAddrLValue(EltAddr, CAExp->EltTy); 740 ExpandTypeFromArgs(CAExp->EltTy, LV, AI); 741 } 742 } else if (auto RExp = dyn_cast<RecordExpansion>(Exp.get())) { 743 llvm::Value *This = LV.getAddress(); 744 for (const CXXBaseSpecifier *BS : RExp->Bases) { 745 // Perform a single step derived-to-base conversion. 746 llvm::Value *Base = 747 GetAddressOfBaseClass(This, Ty->getAsCXXRecordDecl(), &BS, &BS + 1, 748 /*NullCheckValue=*/false, SourceLocation()); 749 LValue SubLV = MakeAddrLValue(Base, BS->getType()); 750 751 // Recurse onto bases. 752 ExpandTypeFromArgs(BS->getType(), SubLV, AI); 753 } 754 for (auto FD : RExp->Fields) { 755 // FIXME: What are the right qualifiers here? 756 LValue SubLV = EmitLValueForField(LV, FD); 757 ExpandTypeFromArgs(FD->getType(), SubLV, AI); 758 } 759 } else if (auto CExp = dyn_cast<ComplexExpansion>(Exp.get())) { 760 llvm::Value *RealAddr = 761 Builder.CreateStructGEP(nullptr, LV.getAddress(), 0, "real"); 762 EmitStoreThroughLValue(RValue::get(*AI++), 763 MakeAddrLValue(RealAddr, CExp->EltTy)); 764 llvm::Value *ImagAddr = 765 Builder.CreateStructGEP(nullptr, LV.getAddress(), 1, "imag"); 766 EmitStoreThroughLValue(RValue::get(*AI++), 767 MakeAddrLValue(ImagAddr, CExp->EltTy)); 768 } else { 769 assert(isa<NoExpansion>(Exp.get())); 770 EmitStoreThroughLValue(RValue::get(*AI++), LV); 771 } 772} 773 774void CodeGenFunction::ExpandTypeToArgs( 775 QualType Ty, RValue RV, llvm::FunctionType *IRFuncTy, 776 SmallVectorImpl<llvm::Value *> &IRCallArgs, unsigned &IRCallArgPos) { 777 auto Exp = getTypeExpansion(Ty, getContext()); 778 if (auto CAExp = dyn_cast<ConstantArrayExpansion>(Exp.get())) { 779 llvm::Value *Addr = RV.getAggregateAddr(); 780 for (int i = 0, n = CAExp->NumElts; i < n; i++) { 781 llvm::Value *EltAddr = Builder.CreateConstGEP2_32(nullptr, Addr, 0, i); 782 RValue EltRV = 783 convertTempToRValue(EltAddr, CAExp->EltTy, SourceLocation()); 784 ExpandTypeToArgs(CAExp->EltTy, EltRV, IRFuncTy, IRCallArgs, IRCallArgPos); 785 } 786 } else if (auto RExp = dyn_cast<RecordExpansion>(Exp.get())) { 787 llvm::Value *This = RV.getAggregateAddr(); 788 for (const CXXBaseSpecifier *BS : RExp->Bases) { 789 // Perform a single step derived-to-base conversion. 790 llvm::Value *Base = 791 GetAddressOfBaseClass(This, Ty->getAsCXXRecordDecl(), &BS, &BS + 1, 792 /*NullCheckValue=*/false, SourceLocation()); 793 RValue BaseRV = RValue::getAggregate(Base); 794 795 // Recurse onto bases. 796 ExpandTypeToArgs(BS->getType(), BaseRV, IRFuncTy, IRCallArgs, 797 IRCallArgPos); 798 } 799 800 LValue LV = MakeAddrLValue(This, Ty); 801 for (auto FD : RExp->Fields) { 802 RValue FldRV = EmitRValueForField(LV, FD, SourceLocation()); 803 ExpandTypeToArgs(FD->getType(), FldRV, IRFuncTy, IRCallArgs, 804 IRCallArgPos); 805 } 806 } else if (isa<ComplexExpansion>(Exp.get())) { 807 ComplexPairTy CV = RV.getComplexVal(); 808 IRCallArgs[IRCallArgPos++] = CV.first; 809 IRCallArgs[IRCallArgPos++] = CV.second; 810 } else { 811 assert(isa<NoExpansion>(Exp.get())); 812 assert(RV.isScalar() && 813 "Unexpected non-scalar rvalue during struct expansion."); 814 815 // Insert a bitcast as needed. 816 llvm::Value *V = RV.getScalarVal(); 817 if (IRCallArgPos < IRFuncTy->getNumParams() && 818 V->getType() != IRFuncTy->getParamType(IRCallArgPos)) 819 V = Builder.CreateBitCast(V, IRFuncTy->getParamType(IRCallArgPos)); 820 821 IRCallArgs[IRCallArgPos++] = V; 822 } 823} 824 825/// EnterStructPointerForCoercedAccess - Given a struct pointer that we are 826/// accessing some number of bytes out of it, try to gep into the struct to get 827/// at its inner goodness. Dive as deep as possible without entering an element 828/// with an in-memory size smaller than DstSize. 829static llvm::Value * 830EnterStructPointerForCoercedAccess(llvm::Value *SrcPtr, 831 llvm::StructType *SrcSTy, 832 uint64_t DstSize, CodeGenFunction &CGF) { 833 // We can't dive into a zero-element struct. 834 if (SrcSTy->getNumElements() == 0) return SrcPtr; 835 836 llvm::Type *FirstElt = SrcSTy->getElementType(0); 837 838 // If the first elt is at least as large as what we're looking for, or if the 839 // first element is the same size as the whole struct, we can enter it. The 840 // comparison must be made on the store size and not the alloca size. Using 841 // the alloca size may overstate the size of the load. 842 uint64_t FirstEltSize = 843 CGF.CGM.getDataLayout().getTypeStoreSize(FirstElt); 844 if (FirstEltSize < DstSize && 845 FirstEltSize < CGF.CGM.getDataLayout().getTypeStoreSize(SrcSTy)) 846 return SrcPtr; 847 848 // GEP into the first element. 849 SrcPtr = CGF.Builder.CreateConstGEP2_32(SrcSTy, SrcPtr, 0, 0, "coerce.dive"); 850 851 // If the first element is a struct, recurse. 852 llvm::Type *SrcTy = 853 cast<llvm::PointerType>(SrcPtr->getType())->getElementType(); 854 if (llvm::StructType *SrcSTy = dyn_cast<llvm::StructType>(SrcTy)) 855 return EnterStructPointerForCoercedAccess(SrcPtr, SrcSTy, DstSize, CGF); 856 857 return SrcPtr; 858} 859 860/// CoerceIntOrPtrToIntOrPtr - Convert a value Val to the specific Ty where both 861/// are either integers or pointers. This does a truncation of the value if it 862/// is too large or a zero extension if it is too small. 863/// 864/// This behaves as if the value were coerced through memory, so on big-endian 865/// targets the high bits are preserved in a truncation, while little-endian 866/// targets preserve the low bits. 867static llvm::Value *CoerceIntOrPtrToIntOrPtr(llvm::Value *Val, 868 llvm::Type *Ty, 869 CodeGenFunction &CGF) { 870 if (Val->getType() == Ty) 871 return Val; 872 873 if (isa<llvm::PointerType>(Val->getType())) { 874 // If this is Pointer->Pointer avoid conversion to and from int. 875 if (isa<llvm::PointerType>(Ty)) 876 return CGF.Builder.CreateBitCast(Val, Ty, "coerce.val"); 877 878 // Convert the pointer to an integer so we can play with its width. 879 Val = CGF.Builder.CreatePtrToInt(Val, CGF.IntPtrTy, "coerce.val.pi"); 880 } 881 882 llvm::Type *DestIntTy = Ty; 883 if (isa<llvm::PointerType>(DestIntTy)) 884 DestIntTy = CGF.IntPtrTy; 885 886 if (Val->getType() != DestIntTy) { 887 const llvm::DataLayout &DL = CGF.CGM.getDataLayout(); 888 if (DL.isBigEndian()) { 889 // Preserve the high bits on big-endian targets. 890 // That is what memory coercion does. 891 uint64_t SrcSize = DL.getTypeSizeInBits(Val->getType()); 892 uint64_t DstSize = DL.getTypeSizeInBits(DestIntTy); 893 894 if (SrcSize > DstSize) { 895 Val = CGF.Builder.CreateLShr(Val, SrcSize - DstSize, "coerce.highbits"); 896 Val = CGF.Builder.CreateTrunc(Val, DestIntTy, "coerce.val.ii"); 897 } else { 898 Val = CGF.Builder.CreateZExt(Val, DestIntTy, "coerce.val.ii"); 899 Val = CGF.Builder.CreateShl(Val, DstSize - SrcSize, "coerce.highbits"); 900 } 901 } else { 902 // Little-endian targets preserve the low bits. No shifts required. 903 Val = CGF.Builder.CreateIntCast(Val, DestIntTy, false, "coerce.val.ii"); 904 } 905 } 906 907 if (isa<llvm::PointerType>(Ty)) 908 Val = CGF.Builder.CreateIntToPtr(Val, Ty, "coerce.val.ip"); 909 return Val; 910} 911 912 913 914/// CreateCoercedLoad - Create a load from \arg SrcPtr interpreted as 915/// a pointer to an object of type \arg Ty, known to be aligned to 916/// \arg SrcAlign bytes. 917/// 918/// This safely handles the case when the src type is smaller than the 919/// destination type; in this situation the values of bits which not 920/// present in the src are undefined. 921static llvm::Value *CreateCoercedLoad(llvm::Value *SrcPtr, 922 llvm::Type *Ty, CharUnits SrcAlign, 923 CodeGenFunction &CGF) { 924 llvm::Type *SrcTy = 925 cast<llvm::PointerType>(SrcPtr->getType())->getElementType(); 926 927 // If SrcTy and Ty are the same, just do a load. 928 if (SrcTy == Ty) 929 return CGF.Builder.CreateAlignedLoad(SrcPtr, SrcAlign.getQuantity()); 930 931 uint64_t DstSize = CGF.CGM.getDataLayout().getTypeAllocSize(Ty); 932 933 if (llvm::StructType *SrcSTy = dyn_cast<llvm::StructType>(SrcTy)) { 934 SrcPtr = EnterStructPointerForCoercedAccess(SrcPtr, SrcSTy, DstSize, CGF); 935 SrcTy = cast<llvm::PointerType>(SrcPtr->getType())->getElementType(); 936 } 937 938 uint64_t SrcSize = CGF.CGM.getDataLayout().getTypeAllocSize(SrcTy); 939 940 // If the source and destination are integer or pointer types, just do an 941 // extension or truncation to the desired type. 942 if ((isa<llvm::IntegerType>(Ty) || isa<llvm::PointerType>(Ty)) && 943 (isa<llvm::IntegerType>(SrcTy) || isa<llvm::PointerType>(SrcTy))) { 944 llvm::LoadInst *Load = 945 CGF.Builder.CreateAlignedLoad(SrcPtr, SrcAlign.getQuantity()); 946 return CoerceIntOrPtrToIntOrPtr(Load, Ty, CGF); 947 } 948 949 // If load is legal, just bitcast the src pointer. 950 if (SrcSize >= DstSize) { 951 // Generally SrcSize is never greater than DstSize, since this means we are 952 // losing bits. However, this can happen in cases where the structure has 953 // additional padding, for example due to a user specified alignment. 954 // 955 // FIXME: Assert that we aren't truncating non-padding bits when have access 956 // to that information. 957 llvm::Value *Casted = 958 CGF.Builder.CreateBitCast(SrcPtr, llvm::PointerType::getUnqual(Ty)); 959 return CGF.Builder.CreateAlignedLoad(Casted, SrcAlign.getQuantity()); 960 } 961 962 // Otherwise do coercion through memory. This is stupid, but 963 // simple. 964 llvm::AllocaInst *Tmp = CGF.CreateTempAlloca(Ty); 965 Tmp->setAlignment(SrcAlign.getQuantity()); 966 llvm::Type *I8PtrTy = CGF.Builder.getInt8PtrTy(); 967 llvm::Value *Casted = CGF.Builder.CreateBitCast(Tmp, I8PtrTy); 968 llvm::Value *SrcCasted = CGF.Builder.CreateBitCast(SrcPtr, I8PtrTy); 969 CGF.Builder.CreateMemCpy(Casted, SrcCasted, 970 llvm::ConstantInt::get(CGF.IntPtrTy, SrcSize), 971 SrcAlign.getQuantity(), false); 972 return CGF.Builder.CreateAlignedLoad(Tmp, SrcAlign.getQuantity()); 973} 974 975// Function to store a first-class aggregate into memory. We prefer to 976// store the elements rather than the aggregate to be more friendly to 977// fast-isel. 978// FIXME: Do we need to recurse here? 979static void BuildAggStore(CodeGenFunction &CGF, llvm::Value *Val, 980 llvm::Value *DestPtr, bool DestIsVolatile, 981 CharUnits DestAlign) { 982 // Prefer scalar stores to first-class aggregate stores. 983 if (llvm::StructType *STy = 984 dyn_cast<llvm::StructType>(Val->getType())) { 985 const llvm::StructLayout *Layout = 986 CGF.CGM.getDataLayout().getStructLayout(STy); 987 988 for (unsigned i = 0, e = STy->getNumElements(); i != e; ++i) { 989 llvm::Value *EltPtr = CGF.Builder.CreateConstGEP2_32(STy, DestPtr, 0, i); 990 llvm::Value *Elt = CGF.Builder.CreateExtractValue(Val, i); 991 uint64_t EltOffset = Layout->getElementOffset(i); 992 CharUnits EltAlign = 993 DestAlign.alignmentAtOffset(CharUnits::fromQuantity(EltOffset)); 994 CGF.Builder.CreateAlignedStore(Elt, EltPtr, EltAlign.getQuantity(), 995 DestIsVolatile); 996 } 997 } else { 998 CGF.Builder.CreateAlignedStore(Val, DestPtr, DestAlign.getQuantity(), 999 DestIsVolatile); 1000 } 1001} 1002 1003/// CreateCoercedStore - Create a store to \arg DstPtr from \arg Src, 1004/// where the source and destination may have different types. The 1005/// destination is known to be aligned to \arg DstAlign bytes. 1006/// 1007/// This safely handles the case when the src type is larger than the 1008/// destination type; the upper bits of the src will be lost. 1009static void CreateCoercedStore(llvm::Value *Src, 1010 llvm::Value *DstPtr, 1011 bool DstIsVolatile, 1012 CharUnits DstAlign, 1013 CodeGenFunction &CGF) { 1014 llvm::Type *SrcTy = Src->getType(); 1015 llvm::Type *DstTy = 1016 cast<llvm::PointerType>(DstPtr->getType())->getElementType(); 1017 if (SrcTy == DstTy) { 1018 CGF.Builder.CreateAlignedStore(Src, DstPtr, DstAlign.getQuantity(), 1019 DstIsVolatile); 1020 return; 1021 } 1022 1023 uint64_t SrcSize = CGF.CGM.getDataLayout().getTypeAllocSize(SrcTy); 1024 1025 if (llvm::StructType *DstSTy = dyn_cast<llvm::StructType>(DstTy)) { 1026 DstPtr = EnterStructPointerForCoercedAccess(DstPtr, DstSTy, SrcSize, CGF); 1027 DstTy = cast<llvm::PointerType>(DstPtr->getType())->getElementType(); 1028 } 1029 1030 // If the source and destination are integer or pointer types, just do an 1031 // extension or truncation to the desired type. 1032 if ((isa<llvm::IntegerType>(SrcTy) || isa<llvm::PointerType>(SrcTy)) && 1033 (isa<llvm::IntegerType>(DstTy) || isa<llvm::PointerType>(DstTy))) { 1034 Src = CoerceIntOrPtrToIntOrPtr(Src, DstTy, CGF); 1035 CGF.Builder.CreateAlignedStore(Src, DstPtr, DstAlign.getQuantity(), 1036 DstIsVolatile); 1037 return; 1038 } 1039 1040 uint64_t DstSize = CGF.CGM.getDataLayout().getTypeAllocSize(DstTy); 1041 1042 // If store is legal, just bitcast the src pointer. 1043 if (SrcSize <= DstSize) { 1044 llvm::Value *Casted = 1045 CGF.Builder.CreateBitCast(DstPtr, llvm::PointerType::getUnqual(SrcTy)); 1046 BuildAggStore(CGF, Src, Casted, DstIsVolatile, DstAlign); 1047 } else { 1048 // Otherwise do coercion through memory. This is stupid, but 1049 // simple. 1050 1051 // Generally SrcSize is never greater than DstSize, since this means we are 1052 // losing bits. However, this can happen in cases where the structure has 1053 // additional padding, for example due to a user specified alignment. 1054 // 1055 // FIXME: Assert that we aren't truncating non-padding bits when have access 1056 // to that information. 1057 llvm::AllocaInst *Tmp = CGF.CreateTempAlloca(SrcTy); 1058 Tmp->setAlignment(DstAlign.getQuantity()); 1059 CGF.Builder.CreateAlignedStore(Src, Tmp, DstAlign.getQuantity()); 1060 llvm::Type *I8PtrTy = CGF.Builder.getInt8PtrTy(); 1061 llvm::Value *Casted = CGF.Builder.CreateBitCast(Tmp, I8PtrTy); 1062 llvm::Value *DstCasted = CGF.Builder.CreateBitCast(DstPtr, I8PtrTy); 1063 CGF.Builder.CreateMemCpy(DstCasted, Casted, 1064 llvm::ConstantInt::get(CGF.IntPtrTy, DstSize), 1065 DstAlign.getQuantity(), false); 1066 } 1067} 1068 1069namespace { 1070 1071/// Encapsulates information about the way function arguments from 1072/// CGFunctionInfo should be passed to actual LLVM IR function. 1073class ClangToLLVMArgMapping { 1074 static const unsigned InvalidIndex = ~0U; 1075 unsigned InallocaArgNo; 1076 unsigned SRetArgNo; 1077 unsigned TotalIRArgs; 1078 1079 /// Arguments of LLVM IR function corresponding to single Clang argument. 1080 struct IRArgs { 1081 unsigned PaddingArgIndex; 1082 // Argument is expanded to IR arguments at positions 1083 // [FirstArgIndex, FirstArgIndex + NumberOfArgs). 1084 unsigned FirstArgIndex; 1085 unsigned NumberOfArgs; 1086 1087 IRArgs() 1088 : PaddingArgIndex(InvalidIndex), FirstArgIndex(InvalidIndex), 1089 NumberOfArgs(0) {} 1090 }; 1091 1092 SmallVector<IRArgs, 8> ArgInfo; 1093 1094public: 1095 ClangToLLVMArgMapping(const ASTContext &Context, const CGFunctionInfo &FI, 1096 bool OnlyRequiredArgs = false) 1097 : InallocaArgNo(InvalidIndex), SRetArgNo(InvalidIndex), TotalIRArgs(0), 1098 ArgInfo(OnlyRequiredArgs ? FI.getNumRequiredArgs() : FI.arg_size()) { 1099 construct(Context, FI, OnlyRequiredArgs); 1100 } 1101 1102 bool hasInallocaArg() const { return InallocaArgNo != InvalidIndex; } 1103 unsigned getInallocaArgNo() const { 1104 assert(hasInallocaArg()); 1105 return InallocaArgNo; 1106 } 1107 1108 bool hasSRetArg() const { return SRetArgNo != InvalidIndex; } 1109 unsigned getSRetArgNo() const { 1110 assert(hasSRetArg()); 1111 return SRetArgNo; 1112 } 1113 1114 unsigned totalIRArgs() const { return TotalIRArgs; } 1115 1116 bool hasPaddingArg(unsigned ArgNo) const { 1117 assert(ArgNo < ArgInfo.size()); 1118 return ArgInfo[ArgNo].PaddingArgIndex != InvalidIndex; 1119 } 1120 unsigned getPaddingArgNo(unsigned ArgNo) const { 1121 assert(hasPaddingArg(ArgNo)); 1122 return ArgInfo[ArgNo].PaddingArgIndex; 1123 } 1124 1125 /// Returns index of first IR argument corresponding to ArgNo, and their 1126 /// quantity. 1127 std::pair<unsigned, unsigned> getIRArgs(unsigned ArgNo) const { 1128 assert(ArgNo < ArgInfo.size()); 1129 return std::make_pair(ArgInfo[ArgNo].FirstArgIndex, 1130 ArgInfo[ArgNo].NumberOfArgs); 1131 } 1132 1133private: 1134 void construct(const ASTContext &Context, const CGFunctionInfo &FI, 1135 bool OnlyRequiredArgs); 1136}; 1137 1138void ClangToLLVMArgMapping::construct(const ASTContext &Context, 1139 const CGFunctionInfo &FI, 1140 bool OnlyRequiredArgs) { 1141 unsigned IRArgNo = 0; 1142 bool SwapThisWithSRet = false; 1143 const ABIArgInfo &RetAI = FI.getReturnInfo(); 1144 1145 if (RetAI.getKind() == ABIArgInfo::Indirect) { 1146 SwapThisWithSRet = RetAI.isSRetAfterThis(); 1147 SRetArgNo = SwapThisWithSRet ? 1 : IRArgNo++; 1148 } 1149 1150 unsigned ArgNo = 0; 1151 unsigned NumArgs = OnlyRequiredArgs ? FI.getNumRequiredArgs() : FI.arg_size(); 1152 for (CGFunctionInfo::const_arg_iterator I = FI.arg_begin(); ArgNo < NumArgs; 1153 ++I, ++ArgNo) { 1154 assert(I != FI.arg_end()); 1155 QualType ArgType = I->type; 1156 const ABIArgInfo &AI = I->info; 1157 // Collect data about IR arguments corresponding to Clang argument ArgNo. 1158 auto &IRArgs = ArgInfo[ArgNo]; 1159 1160 if (AI.getPaddingType()) 1161 IRArgs.PaddingArgIndex = IRArgNo++; 1162 1163 switch (AI.getKind()) { 1164 case ABIArgInfo::Extend: 1165 case ABIArgInfo::Direct: { 1166 // FIXME: handle sseregparm someday... 1167 llvm::StructType *STy = dyn_cast<llvm::StructType>(AI.getCoerceToType()); 1168 if (AI.isDirect() && AI.getCanBeFlattened() && STy) { 1169 IRArgs.NumberOfArgs = STy->getNumElements(); 1170 } else { 1171 IRArgs.NumberOfArgs = 1; 1172 } 1173 break; 1174 } 1175 case ABIArgInfo::Indirect: 1176 IRArgs.NumberOfArgs = 1; 1177 break; 1178 case ABIArgInfo::Ignore: 1179 case ABIArgInfo::InAlloca: 1180 // ignore and inalloca doesn't have matching LLVM parameters. 1181 IRArgs.NumberOfArgs = 0; 1182 break; 1183 case ABIArgInfo::Expand: { 1184 IRArgs.NumberOfArgs = getExpansionSize(ArgType, Context); 1185 break; 1186 } 1187 } 1188 1189 if (IRArgs.NumberOfArgs > 0) { 1190 IRArgs.FirstArgIndex = IRArgNo; 1191 IRArgNo += IRArgs.NumberOfArgs; 1192 } 1193 1194 // Skip over the sret parameter when it comes second. We already handled it 1195 // above. 1196 if (IRArgNo == 1 && SwapThisWithSRet) 1197 IRArgNo++; 1198 } 1199 assert(ArgNo == ArgInfo.size()); 1200 1201 if (FI.usesInAlloca()) 1202 InallocaArgNo = IRArgNo++; 1203 1204 TotalIRArgs = IRArgNo; 1205} 1206} // namespace 1207 1208/***/ 1209 1210bool CodeGenModule::ReturnTypeUsesSRet(const CGFunctionInfo &FI) { 1211 return FI.getReturnInfo().isIndirect(); 1212} 1213 1214bool CodeGenModule::ReturnSlotInterferesWithArgs(const CGFunctionInfo &FI) { 1215 return ReturnTypeUsesSRet(FI) && 1216 getTargetCodeGenInfo().doesReturnSlotInterfereWithArgs(); 1217} 1218 1219bool CodeGenModule::ReturnTypeUsesFPRet(QualType ResultType) { 1220 if (const BuiltinType *BT = ResultType->getAs<BuiltinType>()) { 1221 switch (BT->getKind()) { 1222 default: 1223 return false; 1224 case BuiltinType::Float: 1225 return getTarget().useObjCFPRetForRealType(TargetInfo::Float); 1226 case BuiltinType::Double: 1227 return getTarget().useObjCFPRetForRealType(TargetInfo::Double); 1228 case BuiltinType::LongDouble: 1229 return getTarget().useObjCFPRetForRealType(TargetInfo::LongDouble); 1230 } 1231 } 1232 1233 return false; 1234} 1235 1236bool CodeGenModule::ReturnTypeUsesFP2Ret(QualType ResultType) { 1237 if (const ComplexType *CT = ResultType->getAs<ComplexType>()) { 1238 if (const BuiltinType *BT = CT->getElementType()->getAs<BuiltinType>()) { 1239 if (BT->getKind() == BuiltinType::LongDouble) 1240 return getTarget().useObjCFP2RetForComplexLongDouble(); 1241 } 1242 } 1243 1244 return false; 1245} 1246 1247llvm::FunctionType *CodeGenTypes::GetFunctionType(GlobalDecl GD) { 1248 const CGFunctionInfo &FI = arrangeGlobalDeclaration(GD); 1249 return GetFunctionType(FI); 1250} 1251 1252llvm::FunctionType * 1253CodeGenTypes::GetFunctionType(const CGFunctionInfo &FI) { 1254 1255 bool Inserted = FunctionsBeingProcessed.insert(&FI).second; 1256 (void)Inserted; 1257 assert(Inserted && "Recursively being processed?"); 1258 1259 llvm::Type *resultType = nullptr; 1260 const ABIArgInfo &retAI = FI.getReturnInfo(); 1261 switch (retAI.getKind()) { 1262 case ABIArgInfo::Expand: 1263 llvm_unreachable("Invalid ABI kind for return argument"); 1264 1265 case ABIArgInfo::Extend: 1266 case ABIArgInfo::Direct: 1267 resultType = retAI.getCoerceToType(); 1268 break; 1269 1270 case ABIArgInfo::InAlloca: 1271 if (retAI.getInAllocaSRet()) { 1272 // sret things on win32 aren't void, they return the sret pointer. 1273 QualType ret = FI.getReturnType(); 1274 llvm::Type *ty = ConvertType(ret); 1275 unsigned addressSpace = Context.getTargetAddressSpace(ret); 1276 resultType = llvm::PointerType::get(ty, addressSpace); 1277 } else { 1278 resultType = llvm::Type::getVoidTy(getLLVMContext()); 1279 } 1280 break; 1281 1282 case ABIArgInfo::Indirect: { 1283 assert(!retAI.getIndirectAlign() && "Align unused on indirect return."); 1284 resultType = llvm::Type::getVoidTy(getLLVMContext()); 1285 break; 1286 } 1287 1288 case ABIArgInfo::Ignore: 1289 resultType = llvm::Type::getVoidTy(getLLVMContext()); 1290 break; 1291 } 1292 1293 ClangToLLVMArgMapping IRFunctionArgs(getContext(), FI, true); 1294 SmallVector<llvm::Type*, 8> ArgTypes(IRFunctionArgs.totalIRArgs()); 1295 1296 // Add type for sret argument. 1297 if (IRFunctionArgs.hasSRetArg()) { 1298 QualType Ret = FI.getReturnType(); 1299 llvm::Type *Ty = ConvertType(Ret); 1300 unsigned AddressSpace = Context.getTargetAddressSpace(Ret); 1301 ArgTypes[IRFunctionArgs.getSRetArgNo()] = 1302 llvm::PointerType::get(Ty, AddressSpace); 1303 } 1304 1305 // Add type for inalloca argument. 1306 if (IRFunctionArgs.hasInallocaArg()) { 1307 auto ArgStruct = FI.getArgStruct(); 1308 assert(ArgStruct); 1309 ArgTypes[IRFunctionArgs.getInallocaArgNo()] = ArgStruct->getPointerTo(); 1310 } 1311 1312 // Add in all of the required arguments. 1313 unsigned ArgNo = 0; 1314 CGFunctionInfo::const_arg_iterator it = FI.arg_begin(), 1315 ie = it + FI.getNumRequiredArgs(); 1316 for (; it != ie; ++it, ++ArgNo) { 1317 const ABIArgInfo &ArgInfo = it->info; 1318 1319 // Insert a padding type to ensure proper alignment. 1320 if (IRFunctionArgs.hasPaddingArg(ArgNo)) 1321 ArgTypes[IRFunctionArgs.getPaddingArgNo(ArgNo)] = 1322 ArgInfo.getPaddingType(); 1323 1324 unsigned FirstIRArg, NumIRArgs; 1325 std::tie(FirstIRArg, NumIRArgs) = IRFunctionArgs.getIRArgs(ArgNo); 1326 1327 switch (ArgInfo.getKind()) { 1328 case ABIArgInfo::Ignore: 1329 case ABIArgInfo::InAlloca: 1330 assert(NumIRArgs == 0); 1331 break; 1332 1333 case ABIArgInfo::Indirect: { 1334 assert(NumIRArgs == 1); 1335 // indirect arguments are always on the stack, which is addr space #0. 1336 llvm::Type *LTy = ConvertTypeForMem(it->type); 1337 ArgTypes[FirstIRArg] = LTy->getPointerTo(); 1338 break; 1339 } 1340 1341 case ABIArgInfo::Extend: 1342 case ABIArgInfo::Direct: { 1343 // Fast-isel and the optimizer generally like scalar values better than 1344 // FCAs, so we flatten them if this is safe to do for this argument. 1345 llvm::Type *argType = ArgInfo.getCoerceToType(); 1346 llvm::StructType *st = dyn_cast<llvm::StructType>(argType); 1347 if (st && ArgInfo.isDirect() && ArgInfo.getCanBeFlattened()) { 1348 assert(NumIRArgs == st->getNumElements()); 1349 for (unsigned i = 0, e = st->getNumElements(); i != e; ++i) 1350 ArgTypes[FirstIRArg + i] = st->getElementType(i); 1351 } else { 1352 assert(NumIRArgs == 1); 1353 ArgTypes[FirstIRArg] = argType; 1354 } 1355 break; 1356 } 1357 1358 case ABIArgInfo::Expand: 1359 auto ArgTypesIter = ArgTypes.begin() + FirstIRArg; 1360 getExpandedTypes(it->type, ArgTypesIter); 1361 assert(ArgTypesIter == ArgTypes.begin() + FirstIRArg + NumIRArgs); 1362 break; 1363 } 1364 } 1365 1366 bool Erased = FunctionsBeingProcessed.erase(&FI); (void)Erased; 1367 assert(Erased && "Not in set?"); 1368 1369 return llvm::FunctionType::get(resultType, ArgTypes, FI.isVariadic()); 1370} 1371 1372llvm::Type *CodeGenTypes::GetFunctionTypeForVTable(GlobalDecl GD) { 1373 const CXXMethodDecl *MD = cast<CXXMethodDecl>(GD.getDecl()); 1374 const FunctionProtoType *FPT = MD->getType()->getAs<FunctionProtoType>(); 1375 1376 if (!isFuncTypeConvertible(FPT)) 1377 return llvm::StructType::get(getLLVMContext()); 1378 1379 const CGFunctionInfo *Info; 1380 if (isa<CXXDestructorDecl>(MD)) 1381 Info = 1382 &arrangeCXXStructorDeclaration(MD, getFromDtorType(GD.getDtorType())); 1383 else 1384 Info = &arrangeCXXMethodDeclaration(MD); 1385 return GetFunctionType(*Info); 1386} 1387 1388void CodeGenModule::ConstructAttributeList(const CGFunctionInfo &FI, 1389 const Decl *TargetDecl, 1390 AttributeListType &PAL, 1391 unsigned &CallingConv, 1392 bool AttrOnCallSite) { 1393 llvm::AttrBuilder FuncAttrs; 1394 llvm::AttrBuilder RetAttrs; 1395 bool HasOptnone = false; 1396 1397 CallingConv = FI.getEffectiveCallingConvention(); 1398 1399 if (FI.isNoReturn()) 1400 FuncAttrs.addAttribute(llvm::Attribute::NoReturn); 1401 1402 // FIXME: handle sseregparm someday... 1403 if (TargetDecl) { 1404 if (TargetDecl->hasAttr<ReturnsTwiceAttr>()) 1405 FuncAttrs.addAttribute(llvm::Attribute::ReturnsTwice); 1406 if (TargetDecl->hasAttr<NoThrowAttr>()) 1407 FuncAttrs.addAttribute(llvm::Attribute::NoUnwind); 1408 if (TargetDecl->hasAttr<NoReturnAttr>()) 1409 FuncAttrs.addAttribute(llvm::Attribute::NoReturn); 1410 if (TargetDecl->hasAttr<NoDuplicateAttr>()) 1411 FuncAttrs.addAttribute(llvm::Attribute::NoDuplicate); 1412 1413 if (const FunctionDecl *Fn = dyn_cast<FunctionDecl>(TargetDecl)) { 1414 const FunctionProtoType *FPT = Fn->getType()->getAs<FunctionProtoType>(); 1415 if (FPT && FPT->isNothrow(getContext())) 1416 FuncAttrs.addAttribute(llvm::Attribute::NoUnwind); 1417 // Don't use [[noreturn]] or _Noreturn for a call to a virtual function. 1418 // These attributes are not inherited by overloads. 1419 const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(Fn); 1420 if (Fn->isNoReturn() && !(AttrOnCallSite && MD && MD->isVirtual())) 1421 FuncAttrs.addAttribute(llvm::Attribute::NoReturn); 1422 } 1423 1424 // 'const' and 'pure' attribute functions are also nounwind. 1425 if (TargetDecl->hasAttr<ConstAttr>()) { 1426 FuncAttrs.addAttribute(llvm::Attribute::ReadNone); 1427 FuncAttrs.addAttribute(llvm::Attribute::NoUnwind); 1428 } else if (TargetDecl->hasAttr<PureAttr>()) { 1429 FuncAttrs.addAttribute(llvm::Attribute::ReadOnly); 1430 FuncAttrs.addAttribute(llvm::Attribute::NoUnwind); 1431 } 1432 if (TargetDecl->hasAttr<RestrictAttr>()) 1433 RetAttrs.addAttribute(llvm::Attribute::NoAlias); 1434 if (TargetDecl->hasAttr<ReturnsNonNullAttr>()) 1435 RetAttrs.addAttribute(llvm::Attribute::NonNull); 1436 1437 HasOptnone = TargetDecl->hasAttr<OptimizeNoneAttr>(); 1438 } 1439 1440 // OptimizeNoneAttr takes precedence over -Os or -Oz. No warning needed. 1441 if (!HasOptnone) { 1442 if (CodeGenOpts.OptimizeSize) 1443 FuncAttrs.addAttribute(llvm::Attribute::OptimizeForSize); 1444 if (CodeGenOpts.OptimizeSize == 2) 1445 FuncAttrs.addAttribute(llvm::Attribute::MinSize); 1446 } 1447 1448 if (CodeGenOpts.DisableRedZone) 1449 FuncAttrs.addAttribute(llvm::Attribute::NoRedZone); 1450 if (CodeGenOpts.NoImplicitFloat) 1451 FuncAttrs.addAttribute(llvm::Attribute::NoImplicitFloat); 1452 if (CodeGenOpts.EnableSegmentedStacks && 1453 !(TargetDecl && TargetDecl->hasAttr<NoSplitStackAttr>())) 1454 FuncAttrs.addAttribute("split-stack"); 1455 1456 if (AttrOnCallSite) { 1457 // Attributes that should go on the call site only. 1458 if (!CodeGenOpts.SimplifyLibCalls) 1459 FuncAttrs.addAttribute(llvm::Attribute::NoBuiltin); 1460 if (!CodeGenOpts.TrapFuncName.empty()) 1461 FuncAttrs.addAttribute("trap-func-name", CodeGenOpts.TrapFuncName); 1462 } else { 1463 // Attributes that should go on the function, but not the call site. 1464 if (!CodeGenOpts.DisableFPElim) { 1465 FuncAttrs.addAttribute("no-frame-pointer-elim", "false"); 1466 } else if (CodeGenOpts.OmitLeafFramePointer) { 1467 FuncAttrs.addAttribute("no-frame-pointer-elim", "false"); 1468 FuncAttrs.addAttribute("no-frame-pointer-elim-non-leaf"); 1469 } else { 1470 FuncAttrs.addAttribute("no-frame-pointer-elim", "true"); 1471 FuncAttrs.addAttribute("no-frame-pointer-elim-non-leaf"); 1472 } 1473 1474 FuncAttrs.addAttribute("disable-tail-calls", 1475 llvm::toStringRef(CodeGenOpts.DisableTailCalls)); 1476 FuncAttrs.addAttribute("less-precise-fpmad", 1477 llvm::toStringRef(CodeGenOpts.LessPreciseFPMAD)); 1478 FuncAttrs.addAttribute("no-infs-fp-math", 1479 llvm::toStringRef(CodeGenOpts.NoInfsFPMath)); 1480 FuncAttrs.addAttribute("no-nans-fp-math", 1481 llvm::toStringRef(CodeGenOpts.NoNaNsFPMath)); 1482 FuncAttrs.addAttribute("unsafe-fp-math", 1483 llvm::toStringRef(CodeGenOpts.UnsafeFPMath)); 1484 FuncAttrs.addAttribute("use-soft-float", 1485 llvm::toStringRef(CodeGenOpts.SoftFloat)); 1486 FuncAttrs.addAttribute("stack-protector-buffer-size", 1487 llvm::utostr(CodeGenOpts.SSPBufferSize)); 1488 1489 if (!CodeGenOpts.StackRealignment) 1490 FuncAttrs.addAttribute("no-realign-stack"); 1491 1492 // Add target-cpu and target-features attributes to functions. If 1493 // we have a decl for the function and it has a target attribute then 1494 // parse that and add it to the feature set. 1495 StringRef TargetCPU = getTarget().getTargetOpts().CPU; 1496 1497 // TODO: Features gets us the features on the command line including 1498 // feature dependencies. For canonicalization purposes we might want to 1499 // avoid putting features in the target-features set if we know it'll be 1500 // one of the default features in the backend, e.g. corei7-avx and +avx or 1501 // figure out non-explicit dependencies. 1502 // Canonicalize the existing features in a new feature map. 1503 // TODO: Migrate the existing backends to keep the map around rather than 1504 // the vector. 1505 llvm::StringMap<bool> FeatureMap; 1506 for (auto F : getTarget().getTargetOpts().Features) { 1507 const char *Name = F.c_str(); 1508 bool Enabled = Name[0] == '+'; 1509 getTarget().setFeatureEnabled(FeatureMap, Name + 1, Enabled); 1510 } 1511 1512 const FunctionDecl *FD = dyn_cast_or_null<FunctionDecl>(TargetDecl); 1513 if (FD) { 1514 if (const auto *TD = FD->getAttr<TargetAttr>()) { 1515 StringRef FeaturesStr = TD->getFeatures(); 1516 SmallVector<StringRef, 1> AttrFeatures; 1517 FeaturesStr.split(AttrFeatures, ","); 1518 1519 // Grab the various features and prepend a "+" to turn on the feature to 1520 // the backend and add them to our existing set of features. 1521 for (auto &Feature : AttrFeatures) { 1522 // Go ahead and trim whitespace rather than either erroring or 1523 // accepting it weirdly. 1524 Feature = Feature.trim(); 1525 1526 // While we're here iterating check for a different target cpu. 1527 if (Feature.startswith("arch=")) 1528 TargetCPU = Feature.split("=").second.trim(); 1529 else if (Feature.startswith("tune=")) 1530 // We don't support cpu tuning this way currently. 1531 ; 1532 else if (Feature.startswith("fpmath=")) 1533 // TODO: Support the fpmath option this way. It will require checking 1534 // overall feature validity for the function with the rest of the 1535 // attributes on the function. 1536 ; 1537 else if (Feature.startswith("mno-")) 1538 getTarget().setFeatureEnabled(FeatureMap, Feature.split("-").second, 1539 false); 1540 else 1541 getTarget().setFeatureEnabled(FeatureMap, Feature, true); 1542 } 1543 } 1544 } 1545 1546 // Produce the canonical string for this set of features. 1547 std::vector<std::string> Features; 1548 for (llvm::StringMap<bool>::const_iterator it = FeatureMap.begin(), 1549 ie = FeatureMap.end(); 1550 it != ie; ++it) 1551 Features.push_back((it->second ? "+" : "-") + it->first().str()); 1552 1553 // Now add the target-cpu and target-features to the function. 1554 if (TargetCPU != "") 1555 FuncAttrs.addAttribute("target-cpu", TargetCPU); 1556 if (!Features.empty()) { 1557 std::sort(Features.begin(), Features.end()); 1558 FuncAttrs.addAttribute("target-features", 1559 llvm::join(Features.begin(), Features.end(), ",")); 1560 } 1561 } 1562 1563 ClangToLLVMArgMapping IRFunctionArgs(getContext(), FI); 1564 1565 QualType RetTy = FI.getReturnType(); 1566 const ABIArgInfo &RetAI = FI.getReturnInfo(); 1567 switch (RetAI.getKind()) { 1568 case ABIArgInfo::Extend: 1569 if (RetTy->hasSignedIntegerRepresentation()) 1570 RetAttrs.addAttribute(llvm::Attribute::SExt); 1571 else if (RetTy->hasUnsignedIntegerRepresentation()) 1572 RetAttrs.addAttribute(llvm::Attribute::ZExt); 1573 // FALL THROUGH 1574 case ABIArgInfo::Direct: 1575 if (RetAI.getInReg()) 1576 RetAttrs.addAttribute(llvm::Attribute::InReg); 1577 break; 1578 case ABIArgInfo::Ignore: 1579 break; 1580 1581 case ABIArgInfo::InAlloca: 1582 case ABIArgInfo::Indirect: { 1583 // inalloca and sret disable readnone and readonly 1584 FuncAttrs.removeAttribute(llvm::Attribute::ReadOnly) 1585 .removeAttribute(llvm::Attribute::ReadNone); 1586 break; 1587 } 1588 1589 case ABIArgInfo::Expand: 1590 llvm_unreachable("Invalid ABI kind for return argument"); 1591 } 1592 1593 if (const auto *RefTy = RetTy->getAs<ReferenceType>()) { 1594 QualType PTy = RefTy->getPointeeType(); 1595 if (!PTy->isIncompleteType() && PTy->isConstantSizeType()) 1596 RetAttrs.addDereferenceableAttr(getContext().getTypeSizeInChars(PTy) 1597 .getQuantity()); 1598 else if (getContext().getTargetAddressSpace(PTy) == 0) 1599 RetAttrs.addAttribute(llvm::Attribute::NonNull); 1600 } 1601 1602 // Attach return attributes. 1603 if (RetAttrs.hasAttributes()) { 1604 PAL.push_back(llvm::AttributeSet::get( 1605 getLLVMContext(), llvm::AttributeSet::ReturnIndex, RetAttrs)); 1606 } 1607 1608 // Attach attributes to sret. 1609 if (IRFunctionArgs.hasSRetArg()) { 1610 llvm::AttrBuilder SRETAttrs; 1611 SRETAttrs.addAttribute(llvm::Attribute::StructRet); 1612 if (RetAI.getInReg()) 1613 SRETAttrs.addAttribute(llvm::Attribute::InReg); 1614 PAL.push_back(llvm::AttributeSet::get( 1615 getLLVMContext(), IRFunctionArgs.getSRetArgNo() + 1, SRETAttrs)); 1616 } 1617 1618 // Attach attributes to inalloca argument. 1619 if (IRFunctionArgs.hasInallocaArg()) { 1620 llvm::AttrBuilder Attrs; 1621 Attrs.addAttribute(llvm::Attribute::InAlloca); 1622 PAL.push_back(llvm::AttributeSet::get( 1623 getLLVMContext(), IRFunctionArgs.getInallocaArgNo() + 1, Attrs)); 1624 } 1625 1626 unsigned ArgNo = 0; 1627 for (CGFunctionInfo::const_arg_iterator I = FI.arg_begin(), 1628 E = FI.arg_end(); 1629 I != E; ++I, ++ArgNo) { 1630 QualType ParamType = I->type; 1631 const ABIArgInfo &AI = I->info; 1632 llvm::AttrBuilder Attrs; 1633 1634 // Add attribute for padding argument, if necessary. 1635 if (IRFunctionArgs.hasPaddingArg(ArgNo)) { 1636 if (AI.getPaddingInReg()) 1637 PAL.push_back(llvm::AttributeSet::get( 1638 getLLVMContext(), IRFunctionArgs.getPaddingArgNo(ArgNo) + 1, 1639 llvm::Attribute::InReg)); 1640 } 1641 1642 // 'restrict' -> 'noalias' is done in EmitFunctionProlog when we 1643 // have the corresponding parameter variable. It doesn't make 1644 // sense to do it here because parameters are so messed up. 1645 switch (AI.getKind()) { 1646 case ABIArgInfo::Extend: 1647 if (ParamType->isSignedIntegerOrEnumerationType()) 1648 Attrs.addAttribute(llvm::Attribute::SExt); 1649 else if (ParamType->isUnsignedIntegerOrEnumerationType()) { 1650 if (getTypes().getABIInfo().shouldSignExtUnsignedType(ParamType)) 1651 Attrs.addAttribute(llvm::Attribute::SExt); 1652 else 1653 Attrs.addAttribute(llvm::Attribute::ZExt); 1654 } 1655 // FALL THROUGH 1656 case ABIArgInfo::Direct: 1657 if (ArgNo == 0 && FI.isChainCall()) 1658 Attrs.addAttribute(llvm::Attribute::Nest); 1659 else if (AI.getInReg()) 1660 Attrs.addAttribute(llvm::Attribute::InReg); 1661 break; 1662 1663 case ABIArgInfo::Indirect: 1664 if (AI.getInReg()) 1665 Attrs.addAttribute(llvm::Attribute::InReg); 1666 1667 if (AI.getIndirectByVal()) 1668 Attrs.addAttribute(llvm::Attribute::ByVal); 1669 1670 Attrs.addAlignmentAttr(AI.getIndirectAlign()); 1671 1672 // byval disables readnone and readonly. 1673 FuncAttrs.removeAttribute(llvm::Attribute::ReadOnly) 1674 .removeAttribute(llvm::Attribute::ReadNone); 1675 break; 1676 1677 case ABIArgInfo::Ignore: 1678 case ABIArgInfo::Expand: 1679 continue; 1680 1681 case ABIArgInfo::InAlloca: 1682 // inalloca disables readnone and readonly. 1683 FuncAttrs.removeAttribute(llvm::Attribute::ReadOnly) 1684 .removeAttribute(llvm::Attribute::ReadNone); 1685 continue; 1686 } 1687 1688 if (const auto *RefTy = ParamType->getAs<ReferenceType>()) { 1689 QualType PTy = RefTy->getPointeeType(); 1690 if (!PTy->isIncompleteType() && PTy->isConstantSizeType()) 1691 Attrs.addDereferenceableAttr(getContext().getTypeSizeInChars(PTy) 1692 .getQuantity()); 1693 else if (getContext().getTargetAddressSpace(PTy) == 0) 1694 Attrs.addAttribute(llvm::Attribute::NonNull); 1695 } 1696 1697 if (Attrs.hasAttributes()) { 1698 unsigned FirstIRArg, NumIRArgs; 1699 std::tie(FirstIRArg, NumIRArgs) = IRFunctionArgs.getIRArgs(ArgNo); 1700 for (unsigned i = 0; i < NumIRArgs; i++) 1701 PAL.push_back(llvm::AttributeSet::get(getLLVMContext(), 1702 FirstIRArg + i + 1, Attrs)); 1703 } 1704 } 1705 assert(ArgNo == FI.arg_size()); 1706 1707 if (FuncAttrs.hasAttributes()) 1708 PAL.push_back(llvm:: 1709 AttributeSet::get(getLLVMContext(), 1710 llvm::AttributeSet::FunctionIndex, 1711 FuncAttrs)); 1712} 1713 1714/// An argument came in as a promoted argument; demote it back to its 1715/// declared type. 1716static llvm::Value *emitArgumentDemotion(CodeGenFunction &CGF, 1717 const VarDecl *var, 1718 llvm::Value *value) { 1719 llvm::Type *varType = CGF.ConvertType(var->getType()); 1720 1721 // This can happen with promotions that actually don't change the 1722 // underlying type, like the enum promotions. 1723 if (value->getType() == varType) return value; 1724 1725 assert((varType->isIntegerTy() || varType->isFloatingPointTy()) 1726 && "unexpected promotion type"); 1727 1728 if (isa<llvm::IntegerType>(varType)) 1729 return CGF.Builder.CreateTrunc(value, varType, "arg.unpromote"); 1730 1731 return CGF.Builder.CreateFPCast(value, varType, "arg.unpromote"); 1732} 1733 1734/// Returns the attribute (either parameter attribute, or function 1735/// attribute), which declares argument ArgNo to be non-null. 1736static const NonNullAttr *getNonNullAttr(const Decl *FD, const ParmVarDecl *PVD, 1737 QualType ArgType, unsigned ArgNo) { 1738 // FIXME: __attribute__((nonnull)) can also be applied to: 1739 // - references to pointers, where the pointee is known to be 1740 // nonnull (apparently a Clang extension) 1741 // - transparent unions containing pointers 1742 // In the former case, LLVM IR cannot represent the constraint. In 1743 // the latter case, we have no guarantee that the transparent union 1744 // is in fact passed as a pointer. 1745 if (!ArgType->isAnyPointerType() && !ArgType->isBlockPointerType()) 1746 return nullptr; 1747 // First, check attribute on parameter itself. 1748 if (PVD) { 1749 if (auto ParmNNAttr = PVD->getAttr<NonNullAttr>()) 1750 return ParmNNAttr; 1751 } 1752 // Check function attributes. 1753 if (!FD) 1754 return nullptr; 1755 for (const auto *NNAttr : FD->specific_attrs<NonNullAttr>()) { 1756 if (NNAttr->isNonNull(ArgNo)) 1757 return NNAttr; 1758 } 1759 return nullptr; 1760} 1761 1762void CodeGenFunction::EmitFunctionProlog(const CGFunctionInfo &FI, 1763 llvm::Function *Fn, 1764 const FunctionArgList &Args) { 1765 if (CurCodeDecl && CurCodeDecl->hasAttr<NakedAttr>()) 1766 // Naked functions don't have prologues. 1767 return; 1768 1769 // If this is an implicit-return-zero function, go ahead and 1770 // initialize the return value. TODO: it might be nice to have 1771 // a more general mechanism for this that didn't require synthesized 1772 // return statements. 1773 if (const FunctionDecl *FD = dyn_cast_or_null<FunctionDecl>(CurCodeDecl)) { 1774 if (FD->hasImplicitReturnZero()) { 1775 QualType RetTy = FD->getReturnType().getUnqualifiedType(); 1776 llvm::Type* LLVMTy = CGM.getTypes().ConvertType(RetTy); 1777 llvm::Constant* Zero = llvm::Constant::getNullValue(LLVMTy); 1778 Builder.CreateStore(Zero, ReturnValue); 1779 } 1780 } 1781 1782 // FIXME: We no longer need the types from FunctionArgList; lift up and 1783 // simplify. 1784 1785 ClangToLLVMArgMapping IRFunctionArgs(CGM.getContext(), FI); 1786 // Flattened function arguments. 1787 SmallVector<llvm::Argument *, 16> FnArgs; 1788 FnArgs.reserve(IRFunctionArgs.totalIRArgs()); 1789 for (auto &Arg : Fn->args()) { 1790 FnArgs.push_back(&Arg); 1791 } 1792 assert(FnArgs.size() == IRFunctionArgs.totalIRArgs()); 1793 1794 // If we're using inalloca, all the memory arguments are GEPs off of the last 1795 // parameter, which is a pointer to the complete memory area. 1796 llvm::Value *ArgStruct = nullptr; 1797 if (IRFunctionArgs.hasInallocaArg()) { 1798 ArgStruct = FnArgs[IRFunctionArgs.getInallocaArgNo()]; 1799 assert(ArgStruct->getType() == FI.getArgStruct()->getPointerTo()); 1800 } 1801 1802 // Name the struct return parameter. 1803 if (IRFunctionArgs.hasSRetArg()) { 1804 auto AI = FnArgs[IRFunctionArgs.getSRetArgNo()]; 1805 AI->setName("agg.result"); 1806 AI->addAttr(llvm::AttributeSet::get(getLLVMContext(), AI->getArgNo() + 1, 1807 llvm::Attribute::NoAlias)); 1808 } 1809 1810 // Track if we received the parameter as a pointer (indirect, byval, or 1811 // inalloca). If already have a pointer, EmitParmDecl doesn't need to copy it 1812 // into a local alloca for us. 1813 enum ValOrPointer { HaveValue = 0, HavePointer = 1 }; 1814 typedef llvm::PointerIntPair<llvm::Value *, 1> ValueAndIsPtr; 1815 SmallVector<ValueAndIsPtr, 16> ArgVals; 1816 ArgVals.reserve(Args.size()); 1817 1818 // Create a pointer value for every parameter declaration. This usually 1819 // entails copying one or more LLVM IR arguments into an alloca. Don't push 1820 // any cleanups or do anything that might unwind. We do that separately, so 1821 // we can push the cleanups in the correct order for the ABI. 1822 assert(FI.arg_size() == Args.size() && 1823 "Mismatch between function signature & arguments."); 1824 unsigned ArgNo = 0; 1825 CGFunctionInfo::const_arg_iterator info_it = FI.arg_begin(); 1826 for (FunctionArgList::const_iterator i = Args.begin(), e = Args.end(); 1827 i != e; ++i, ++info_it, ++ArgNo) { 1828 const VarDecl *Arg = *i; 1829 QualType Ty = info_it->type; 1830 const ABIArgInfo &ArgI = info_it->info; 1831 1832 bool isPromoted = 1833 isa<ParmVarDecl>(Arg) && cast<ParmVarDecl>(Arg)->isKNRPromoted(); 1834 1835 unsigned FirstIRArg, NumIRArgs; 1836 std::tie(FirstIRArg, NumIRArgs) = IRFunctionArgs.getIRArgs(ArgNo); 1837 1838 switch (ArgI.getKind()) { 1839 case ABIArgInfo::InAlloca: { 1840 assert(NumIRArgs == 0); 1841 llvm::Value *V = 1842 Builder.CreateStructGEP(FI.getArgStruct(), ArgStruct, 1843 ArgI.getInAllocaFieldIndex(), Arg->getName()); 1844 ArgVals.push_back(ValueAndIsPtr(V, HavePointer)); 1845 break; 1846 } 1847 1848 case ABIArgInfo::Indirect: { 1849 assert(NumIRArgs == 1); 1850 llvm::Value *V = FnArgs[FirstIRArg]; 1851 1852 if (!hasScalarEvaluationKind(Ty)) { 1853 // Aggregates and complex variables are accessed by reference. All we 1854 // need to do is realign the value, if requested 1855 if (ArgI.getIndirectRealign()) { 1856 llvm::Value *AlignedTemp = CreateMemTemp(Ty, "coerce"); 1857 1858 // Copy from the incoming argument pointer to the temporary with the 1859 // appropriate alignment. 1860 // 1861 // FIXME: We should have a common utility for generating an aggregate 1862 // copy. 1863 llvm::Type *I8PtrTy = Builder.getInt8PtrTy(); 1864 CharUnits Size = getContext().getTypeSizeInChars(Ty); 1865 llvm::Value *Dst = Builder.CreateBitCast(AlignedTemp, I8PtrTy); 1866 llvm::Value *Src = Builder.CreateBitCast(V, I8PtrTy); 1867 Builder.CreateMemCpy(Dst, 1868 Src, 1869 llvm::ConstantInt::get(IntPtrTy, 1870 Size.getQuantity()), 1871 ArgI.getIndirectAlign(), 1872 false); 1873 V = AlignedTemp; 1874 } 1875 ArgVals.push_back(ValueAndIsPtr(V, HavePointer)); 1876 } else { 1877 // Load scalar value from indirect argument. 1878 V = EmitLoadOfScalar(V, false, ArgI.getIndirectAlign(), Ty, 1879 Arg->getLocStart()); 1880 1881 if (isPromoted) 1882 V = emitArgumentDemotion(*this, Arg, V); 1883 ArgVals.push_back(ValueAndIsPtr(V, HaveValue)); 1884 } 1885 break; 1886 } 1887 1888 case ABIArgInfo::Extend: 1889 case ABIArgInfo::Direct: { 1890 1891 // If we have the trivial case, handle it with no muss and fuss. 1892 if (!isa<llvm::StructType>(ArgI.getCoerceToType()) && 1893 ArgI.getCoerceToType() == ConvertType(Ty) && 1894 ArgI.getDirectOffset() == 0) { 1895 assert(NumIRArgs == 1); 1896 auto AI = FnArgs[FirstIRArg]; 1897 llvm::Value *V = AI; 1898 1899 if (const ParmVarDecl *PVD = dyn_cast<ParmVarDecl>(Arg)) { 1900 if (getNonNullAttr(CurCodeDecl, PVD, PVD->getType(), 1901 PVD->getFunctionScopeIndex())) 1902 AI->addAttr(llvm::AttributeSet::get(getLLVMContext(), 1903 AI->getArgNo() + 1, 1904 llvm::Attribute::NonNull)); 1905 1906 QualType OTy = PVD->getOriginalType(); 1907 if (const auto *ArrTy = 1908 getContext().getAsConstantArrayType(OTy)) { 1909 // A C99 array parameter declaration with the static keyword also 1910 // indicates dereferenceability, and if the size is constant we can 1911 // use the dereferenceable attribute (which requires the size in 1912 // bytes). 1913 if (ArrTy->getSizeModifier() == ArrayType::Static) { 1914 QualType ETy = ArrTy->getElementType(); 1915 uint64_t ArrSize = ArrTy->getSize().getZExtValue(); 1916 if (!ETy->isIncompleteType() && ETy->isConstantSizeType() && 1917 ArrSize) { 1918 llvm::AttrBuilder Attrs; 1919 Attrs.addDereferenceableAttr( 1920 getContext().getTypeSizeInChars(ETy).getQuantity()*ArrSize); 1921 AI->addAttr(llvm::AttributeSet::get(getLLVMContext(), 1922 AI->getArgNo() + 1, Attrs)); 1923 } else if (getContext().getTargetAddressSpace(ETy) == 0) { 1924 AI->addAttr(llvm::AttributeSet::get(getLLVMContext(), 1925 AI->getArgNo() + 1, 1926 llvm::Attribute::NonNull)); 1927 } 1928 } 1929 } else if (const auto *ArrTy = 1930 getContext().getAsVariableArrayType(OTy)) { 1931 // For C99 VLAs with the static keyword, we don't know the size so 1932 // we can't use the dereferenceable attribute, but in addrspace(0) 1933 // we know that it must be nonnull. 1934 if (ArrTy->getSizeModifier() == VariableArrayType::Static && 1935 !getContext().getTargetAddressSpace(ArrTy->getElementType())) 1936 AI->addAttr(llvm::AttributeSet::get(getLLVMContext(), 1937 AI->getArgNo() + 1, 1938 llvm::Attribute::NonNull)); 1939 } 1940 1941 const auto *AVAttr = PVD->getAttr<AlignValueAttr>(); 1942 if (!AVAttr) 1943 if (const auto *TOTy = dyn_cast<TypedefType>(OTy)) 1944 AVAttr = TOTy->getDecl()->getAttr<AlignValueAttr>(); 1945 if (AVAttr) { 1946 llvm::Value *AlignmentValue = 1947 EmitScalarExpr(AVAttr->getAlignment()); 1948 llvm::ConstantInt *AlignmentCI = 1949 cast<llvm::ConstantInt>(AlignmentValue); 1950 unsigned Alignment = 1951 std::min((unsigned) AlignmentCI->getZExtValue(), 1952 +llvm::Value::MaximumAlignment); 1953 1954 llvm::AttrBuilder Attrs; 1955 Attrs.addAlignmentAttr(Alignment); 1956 AI->addAttr(llvm::AttributeSet::get(getLLVMContext(), 1957 AI->getArgNo() + 1, Attrs)); 1958 } 1959 } 1960 1961 if (Arg->getType().isRestrictQualified()) 1962 AI->addAttr(llvm::AttributeSet::get(getLLVMContext(), 1963 AI->getArgNo() + 1, 1964 llvm::Attribute::NoAlias)); 1965 1966 // Ensure the argument is the correct type. 1967 if (V->getType() != ArgI.getCoerceToType()) 1968 V = Builder.CreateBitCast(V, ArgI.getCoerceToType()); 1969 1970 if (isPromoted) 1971 V = emitArgumentDemotion(*this, Arg, V); 1972 1973 if (const CXXMethodDecl *MD = 1974 dyn_cast_or_null<CXXMethodDecl>(CurCodeDecl)) { 1975 if (MD->isVirtual() && Arg == CXXABIThisDecl) 1976 V = CGM.getCXXABI(). 1977 adjustThisParameterInVirtualFunctionPrologue(*this, CurGD, V); 1978 } 1979 1980 // Because of merging of function types from multiple decls it is 1981 // possible for the type of an argument to not match the corresponding 1982 // type in the function type. Since we are codegening the callee 1983 // in here, add a cast to the argument type. 1984 llvm::Type *LTy = ConvertType(Arg->getType()); 1985 if (V->getType() != LTy) 1986 V = Builder.CreateBitCast(V, LTy); 1987 1988 ArgVals.push_back(ValueAndIsPtr(V, HaveValue)); 1989 break; 1990 } 1991 1992 llvm::AllocaInst *Alloca = CreateMemTemp(Ty, Arg->getName()); 1993 1994 // The alignment we need to use is the max of the requested alignment for 1995 // the argument plus the alignment required by our access code below. 1996 unsigned AlignmentToUse = 1997 CGM.getDataLayout().getABITypeAlignment(ArgI.getCoerceToType()); 1998 AlignmentToUse = std::max(AlignmentToUse, 1999 (unsigned)getContext().getDeclAlign(Arg).getQuantity()); 2000 2001 Alloca->setAlignment(AlignmentToUse); 2002 llvm::Value *V = Alloca; 2003 llvm::Value *Ptr = V; // Pointer to store into. 2004 CharUnits PtrAlign = CharUnits::fromQuantity(AlignmentToUse); 2005 2006 // If the value is offset in memory, apply the offset now. 2007 if (unsigned Offs = ArgI.getDirectOffset()) { 2008 Ptr = Builder.CreateBitCast(Ptr, Builder.getInt8PtrTy()); 2009 Ptr = Builder.CreateConstGEP1_32(Builder.getInt8Ty(), Ptr, Offs); 2010 Ptr = Builder.CreateBitCast(Ptr, 2011 llvm::PointerType::getUnqual(ArgI.getCoerceToType())); 2012 PtrAlign = PtrAlign.alignmentAtOffset(CharUnits::fromQuantity(Offs)); 2013 } 2014 2015 // Fast-isel and the optimizer generally like scalar values better than 2016 // FCAs, so we flatten them if this is safe to do for this argument. 2017 llvm::StructType *STy = dyn_cast<llvm::StructType>(ArgI.getCoerceToType()); 2018 if (ArgI.isDirect() && ArgI.getCanBeFlattened() && STy && 2019 STy->getNumElements() > 1) { 2020 uint64_t SrcSize = CGM.getDataLayout().getTypeAllocSize(STy); 2021 llvm::Type *DstTy = 2022 cast<llvm::PointerType>(Ptr->getType())->getElementType(); 2023 uint64_t DstSize = CGM.getDataLayout().getTypeAllocSize(DstTy); 2024 2025 if (SrcSize <= DstSize) { 2026 Ptr = Builder.CreateBitCast(Ptr, llvm::PointerType::getUnqual(STy)); 2027 2028 assert(STy->getNumElements() == NumIRArgs); 2029 for (unsigned i = 0, e = STy->getNumElements(); i != e; ++i) { 2030 auto AI = FnArgs[FirstIRArg + i]; 2031 AI->setName(Arg->getName() + ".coerce" + Twine(i)); 2032 llvm::Value *EltPtr = Builder.CreateConstGEP2_32(STy, Ptr, 0, i); 2033 Builder.CreateStore(AI, EltPtr); 2034 } 2035 } else { 2036 llvm::AllocaInst *TempAlloca = 2037 CreateTempAlloca(ArgI.getCoerceToType(), "coerce"); 2038 TempAlloca->setAlignment(AlignmentToUse); 2039 llvm::Value *TempV = TempAlloca; 2040 2041 assert(STy->getNumElements() == NumIRArgs); 2042 for (unsigned i = 0, e = STy->getNumElements(); i != e; ++i) { 2043 auto AI = FnArgs[FirstIRArg + i]; 2044 AI->setName(Arg->getName() + ".coerce" + Twine(i)); 2045 llvm::Value *EltPtr = 2046 Builder.CreateConstGEP2_32(ArgI.getCoerceToType(), TempV, 0, i); 2047 Builder.CreateStore(AI, EltPtr); 2048 } 2049 2050 Builder.CreateMemCpy(Ptr, TempV, DstSize, AlignmentToUse); 2051 } 2052 } else { 2053 // Simple case, just do a coerced store of the argument into the alloca. 2054 assert(NumIRArgs == 1); 2055 auto AI = FnArgs[FirstIRArg]; 2056 AI->setName(Arg->getName() + ".coerce"); 2057 CreateCoercedStore(AI, Ptr, /*DestIsVolatile=*/false, PtrAlign, *this); 2058 } 2059 2060 2061 // Match to what EmitParmDecl is expecting for this type. 2062 if (CodeGenFunction::hasScalarEvaluationKind(Ty)) { 2063 V = EmitLoadOfScalar(V, false, AlignmentToUse, Ty, Arg->getLocStart()); 2064 if (isPromoted) 2065 V = emitArgumentDemotion(*this, Arg, V); 2066 ArgVals.push_back(ValueAndIsPtr(V, HaveValue)); 2067 } else { 2068 ArgVals.push_back(ValueAndIsPtr(V, HavePointer)); 2069 } 2070 break; 2071 } 2072 2073 case ABIArgInfo::Expand: { 2074 // If this structure was expanded into multiple arguments then 2075 // we need to create a temporary and reconstruct it from the 2076 // arguments. 2077 llvm::AllocaInst *Alloca = CreateMemTemp(Ty); 2078 CharUnits Align = getContext().getDeclAlign(Arg); 2079 Alloca->setAlignment(Align.getQuantity()); 2080 LValue LV = MakeAddrLValue(Alloca, Ty, Align); 2081 ArgVals.push_back(ValueAndIsPtr(Alloca, HavePointer)); 2082 2083 auto FnArgIter = FnArgs.begin() + FirstIRArg; 2084 ExpandTypeFromArgs(Ty, LV, FnArgIter); 2085 assert(FnArgIter == FnArgs.begin() + FirstIRArg + NumIRArgs); 2086 for (unsigned i = 0, e = NumIRArgs; i != e; ++i) { 2087 auto AI = FnArgs[FirstIRArg + i]; 2088 AI->setName(Arg->getName() + "." + Twine(i)); 2089 } 2090 break; 2091 } 2092 2093 case ABIArgInfo::Ignore: 2094 assert(NumIRArgs == 0); 2095 // Initialize the local variable appropriately. 2096 if (!hasScalarEvaluationKind(Ty)) { 2097 ArgVals.push_back(ValueAndIsPtr(CreateMemTemp(Ty), HavePointer)); 2098 } else { 2099 llvm::Value *U = llvm::UndefValue::get(ConvertType(Arg->getType())); 2100 ArgVals.push_back(ValueAndIsPtr(U, HaveValue)); 2101 } 2102 break; 2103 } 2104 } 2105 2106 if (getTarget().getCXXABI().areArgsDestroyedLeftToRightInCallee()) { 2107 for (int I = Args.size() - 1; I >= 0; --I) 2108 EmitParmDecl(*Args[I], ArgVals[I].getPointer(), ArgVals[I].getInt(), 2109 I + 1); 2110 } else { 2111 for (unsigned I = 0, E = Args.size(); I != E; ++I) 2112 EmitParmDecl(*Args[I], ArgVals[I].getPointer(), ArgVals[I].getInt(), 2113 I + 1); 2114 } 2115} 2116 2117static void eraseUnusedBitCasts(llvm::Instruction *insn) { 2118 while (insn->use_empty()) { 2119 llvm::BitCastInst *bitcast = dyn_cast<llvm::BitCastInst>(insn); 2120 if (!bitcast) return; 2121 2122 // This is "safe" because we would have used a ConstantExpr otherwise. 2123 insn = cast<llvm::Instruction>(bitcast->getOperand(0)); 2124 bitcast->eraseFromParent(); 2125 } 2126} 2127 2128/// Try to emit a fused autorelease of a return result. 2129static llvm::Value *tryEmitFusedAutoreleaseOfResult(CodeGenFunction &CGF, 2130 llvm::Value *result) { 2131 // We must be immediately followed the cast. 2132 llvm::BasicBlock *BB = CGF.Builder.GetInsertBlock(); 2133 if (BB->empty()) return nullptr; 2134 if (&BB->back() != result) return nullptr; 2135 2136 llvm::Type *resultType = result->getType(); 2137 2138 // result is in a BasicBlock and is therefore an Instruction. 2139 llvm::Instruction *generator = cast<llvm::Instruction>(result); 2140 2141 SmallVector<llvm::Instruction*,4> insnsToKill; 2142 2143 // Look for: 2144 // %generator = bitcast %type1* %generator2 to %type2* 2145 while (llvm::BitCastInst *bitcast = dyn_cast<llvm::BitCastInst>(generator)) { 2146 // We would have emitted this as a constant if the operand weren't 2147 // an Instruction. 2148 generator = cast<llvm::Instruction>(bitcast->getOperand(0)); 2149 2150 // Require the generator to be immediately followed by the cast. 2151 if (generator->getNextNode() != bitcast) 2152 return nullptr; 2153 2154 insnsToKill.push_back(bitcast); 2155 } 2156 2157 // Look for: 2158 // %generator = call i8* @objc_retain(i8* %originalResult) 2159 // or 2160 // %generator = call i8* @objc_retainAutoreleasedReturnValue(i8* %originalResult) 2161 llvm::CallInst *call = dyn_cast<llvm::CallInst>(generator); 2162 if (!call) return nullptr; 2163 2164 bool doRetainAutorelease; 2165 2166 if (call->getCalledValue() == CGF.CGM.getARCEntrypoints().objc_retain) { 2167 doRetainAutorelease = true; 2168 } else if (call->getCalledValue() == CGF.CGM.getARCEntrypoints() 2169 .objc_retainAutoreleasedReturnValue) { 2170 doRetainAutorelease = false; 2171 2172 // If we emitted an assembly marker for this call (and the 2173 // ARCEntrypoints field should have been set if so), go looking 2174 // for that call. If we can't find it, we can't do this 2175 // optimization. But it should always be the immediately previous 2176 // instruction, unless we needed bitcasts around the call. 2177 if (CGF.CGM.getARCEntrypoints().retainAutoreleasedReturnValueMarker) { 2178 llvm::Instruction *prev = call->getPrevNode(); 2179 assert(prev); 2180 if (isa<llvm::BitCastInst>(prev)) { 2181 prev = prev->getPrevNode(); 2182 assert(prev); 2183 } 2184 assert(isa<llvm::CallInst>(prev)); 2185 assert(cast<llvm::CallInst>(prev)->getCalledValue() == 2186 CGF.CGM.getARCEntrypoints().retainAutoreleasedReturnValueMarker); 2187 insnsToKill.push_back(prev); 2188 } 2189 } else { 2190 return nullptr; 2191 } 2192 2193 result = call->getArgOperand(0); 2194 insnsToKill.push_back(call); 2195 2196 // Keep killing bitcasts, for sanity. Note that we no longer care 2197 // about precise ordering as long as there's exactly one use. 2198 while (llvm::BitCastInst *bitcast = dyn_cast<llvm::BitCastInst>(result)) { 2199 if (!bitcast->hasOneUse()) break; 2200 insnsToKill.push_back(bitcast); 2201 result = bitcast->getOperand(0); 2202 } 2203 2204 // Delete all the unnecessary instructions, from latest to earliest. 2205 for (SmallVectorImpl<llvm::Instruction*>::iterator 2206 i = insnsToKill.begin(), e = insnsToKill.end(); i != e; ++i) 2207 (*i)->eraseFromParent(); 2208 2209 // Do the fused retain/autorelease if we were asked to. 2210 if (doRetainAutorelease) 2211 result = CGF.EmitARCRetainAutoreleaseReturnValue(result); 2212 2213 // Cast back to the result type. 2214 return CGF.Builder.CreateBitCast(result, resultType); 2215} 2216 2217/// If this is a +1 of the value of an immutable 'self', remove it. 2218static llvm::Value *tryRemoveRetainOfSelf(CodeGenFunction &CGF, 2219 llvm::Value *result) { 2220 // This is only applicable to a method with an immutable 'self'. 2221 const ObjCMethodDecl *method = 2222 dyn_cast_or_null<ObjCMethodDecl>(CGF.CurCodeDecl); 2223 if (!method) return nullptr; 2224 const VarDecl *self = method->getSelfDecl(); 2225 if (!self->getType().isConstQualified()) return nullptr; 2226 2227 // Look for a retain call. 2228 llvm::CallInst *retainCall = 2229 dyn_cast<llvm::CallInst>(result->stripPointerCasts()); 2230 if (!retainCall || 2231 retainCall->getCalledValue() != CGF.CGM.getARCEntrypoints().objc_retain) 2232 return nullptr; 2233 2234 // Look for an ordinary load of 'self'. 2235 llvm::Value *retainedValue = retainCall->getArgOperand(0); 2236 llvm::LoadInst *load = 2237 dyn_cast<llvm::LoadInst>(retainedValue->stripPointerCasts()); 2238 if (!load || load->isAtomic() || load->isVolatile() || 2239 load->getPointerOperand() != CGF.GetAddrOfLocalVar(self)) 2240 return nullptr; 2241 2242 // Okay! Burn it all down. This relies for correctness on the 2243 // assumption that the retain is emitted as part of the return and 2244 // that thereafter everything is used "linearly". 2245 llvm::Type *resultType = result->getType(); 2246 eraseUnusedBitCasts(cast<llvm::Instruction>(result)); 2247 assert(retainCall->use_empty()); 2248 retainCall->eraseFromParent(); 2249 eraseUnusedBitCasts(cast<llvm::Instruction>(retainedValue)); 2250 2251 return CGF.Builder.CreateBitCast(load, resultType); 2252} 2253 2254/// Emit an ARC autorelease of the result of a function. 2255/// 2256/// \return the value to actually return from the function 2257static llvm::Value *emitAutoreleaseOfResult(CodeGenFunction &CGF, 2258 llvm::Value *result) { 2259 // If we're returning 'self', kill the initial retain. This is a 2260 // heuristic attempt to "encourage correctness" in the really unfortunate 2261 // case where we have a return of self during a dealloc and we desperately 2262 // need to avoid the possible autorelease. 2263 if (llvm::Value *self = tryRemoveRetainOfSelf(CGF, result)) 2264 return self; 2265 2266 // At -O0, try to emit a fused retain/autorelease. 2267 if (CGF.shouldUseFusedARCCalls()) 2268 if (llvm::Value *fused = tryEmitFusedAutoreleaseOfResult(CGF, result)) 2269 return fused; 2270 2271 return CGF.EmitARCAutoreleaseReturnValue(result); 2272} 2273 2274/// Heuristically search for a dominating store to the return-value slot. 2275static llvm::StoreInst *findDominatingStoreToReturnValue(CodeGenFunction &CGF) { 2276 // If there are multiple uses of the return-value slot, just check 2277 // for something immediately preceding the IP. Sometimes this can 2278 // happen with how we generate implicit-returns; it can also happen 2279 // with noreturn cleanups. 2280 if (!CGF.ReturnValue->hasOneUse()) { 2281 llvm::BasicBlock *IP = CGF.Builder.GetInsertBlock(); 2282 if (IP->empty()) return nullptr; 2283 llvm::Instruction *I = &IP->back(); 2284 2285 // Skip lifetime markers 2286 for (llvm::BasicBlock::reverse_iterator II = IP->rbegin(), 2287 IE = IP->rend(); 2288 II != IE; ++II) { 2289 if (llvm::IntrinsicInst *Intrinsic = 2290 dyn_cast<llvm::IntrinsicInst>(&*II)) { 2291 if (Intrinsic->getIntrinsicID() == llvm::Intrinsic::lifetime_end) { 2292 const llvm::Value *CastAddr = Intrinsic->getArgOperand(1); 2293 ++II; 2294 if (II == IE) 2295 break; 2296 if (isa<llvm::BitCastInst>(&*II) && (CastAddr == &*II)) 2297 continue; 2298 } 2299 } 2300 I = &*II; 2301 break; 2302 } 2303 2304 llvm::StoreInst *store = dyn_cast<llvm::StoreInst>(I); 2305 if (!store) return nullptr; 2306 if (store->getPointerOperand() != CGF.ReturnValue) return nullptr; 2307 assert(!store->isAtomic() && !store->isVolatile()); // see below 2308 return store; 2309 } 2310 2311 llvm::StoreInst *store = 2312 dyn_cast<llvm::StoreInst>(CGF.ReturnValue->user_back()); 2313 if (!store) return nullptr; 2314 2315 // These aren't actually possible for non-coerced returns, and we 2316 // only care about non-coerced returns on this code path. 2317 assert(!store->isAtomic() && !store->isVolatile()); 2318 2319 // Now do a first-and-dirty dominance check: just walk up the 2320 // single-predecessors chain from the current insertion point. 2321 llvm::BasicBlock *StoreBB = store->getParent(); 2322 llvm::BasicBlock *IP = CGF.Builder.GetInsertBlock(); 2323 while (IP != StoreBB) { 2324 if (!(IP = IP->getSinglePredecessor())) 2325 return nullptr; 2326 } 2327 2328 // Okay, the store's basic block dominates the insertion point; we 2329 // can do our thing. 2330 return store; 2331} 2332 2333void CodeGenFunction::EmitFunctionEpilog(const CGFunctionInfo &FI, 2334 bool EmitRetDbgLoc, 2335 SourceLocation EndLoc) { 2336 if (CurCodeDecl && CurCodeDecl->hasAttr<NakedAttr>()) { 2337 // Naked functions don't have epilogues. 2338 Builder.CreateUnreachable(); 2339 return; 2340 } 2341 2342 // Functions with no result always return void. 2343 if (!ReturnValue) { 2344 Builder.CreateRetVoid(); 2345 return; 2346 } 2347 2348 llvm::DebugLoc RetDbgLoc; 2349 llvm::Value *RV = nullptr; 2350 QualType RetTy = FI.getReturnType(); 2351 const ABIArgInfo &RetAI = FI.getReturnInfo(); 2352 2353 switch (RetAI.getKind()) { 2354 case ABIArgInfo::InAlloca: 2355 // Aggregrates get evaluated directly into the destination. Sometimes we 2356 // need to return the sret value in a register, though. 2357 assert(hasAggregateEvaluationKind(RetTy)); 2358 if (RetAI.getInAllocaSRet()) { 2359 llvm::Function::arg_iterator EI = CurFn->arg_end(); 2360 --EI; 2361 llvm::Value *ArgStruct = EI; 2362 llvm::Value *SRet = Builder.CreateStructGEP( 2363 nullptr, ArgStruct, RetAI.getInAllocaFieldIndex()); 2364 RV = Builder.CreateLoad(SRet, "sret"); 2365 } 2366 break; 2367 2368 case ABIArgInfo::Indirect: { 2369 auto AI = CurFn->arg_begin(); 2370 if (RetAI.isSRetAfterThis()) 2371 ++AI; 2372 switch (getEvaluationKind(RetTy)) { 2373 case TEK_Complex: { 2374 ComplexPairTy RT = 2375 EmitLoadOfComplex(MakeNaturalAlignAddrLValue(ReturnValue, RetTy), 2376 EndLoc); 2377 EmitStoreOfComplex(RT, MakeNaturalAlignAddrLValue(AI, RetTy), 2378 /*isInit*/ true); 2379 break; 2380 } 2381 case TEK_Aggregate: 2382 // Do nothing; aggregrates get evaluated directly into the destination. 2383 break; 2384 case TEK_Scalar: 2385 EmitStoreOfScalar(Builder.CreateLoad(ReturnValue), 2386 MakeNaturalAlignAddrLValue(AI, RetTy), 2387 /*isInit*/ true); 2388 break; 2389 } 2390 break; 2391 } 2392 2393 case ABIArgInfo::Extend: 2394 case ABIArgInfo::Direct: 2395 if (RetAI.getCoerceToType() == ConvertType(RetTy) && 2396 RetAI.getDirectOffset() == 0) { 2397 // The internal return value temp always will have pointer-to-return-type 2398 // type, just do a load. 2399 2400 // If there is a dominating store to ReturnValue, we can elide 2401 // the load, zap the store, and usually zap the alloca. 2402 if (llvm::StoreInst *SI = 2403 findDominatingStoreToReturnValue(*this)) { 2404 // Reuse the debug location from the store unless there is 2405 // cleanup code to be emitted between the store and return 2406 // instruction. 2407 if (EmitRetDbgLoc && !AutoreleaseResult) 2408 RetDbgLoc = SI->getDebugLoc(); 2409 // Get the stored value and nuke the now-dead store. 2410 RV = SI->getValueOperand(); 2411 SI->eraseFromParent(); 2412 2413 // If that was the only use of the return value, nuke it as well now. 2414 if (ReturnValue->use_empty() && isa<llvm::AllocaInst>(ReturnValue)) { 2415 cast<llvm::AllocaInst>(ReturnValue)->eraseFromParent(); 2416 ReturnValue = nullptr; 2417 } 2418 2419 // Otherwise, we have to do a simple load. 2420 } else { 2421 RV = Builder.CreateLoad(ReturnValue); 2422 } 2423 } else { 2424 llvm::Value *V = ReturnValue; 2425 CharUnits Align = getContext().getTypeAlignInChars(RetTy); 2426 // If the value is offset in memory, apply the offset now. 2427 if (unsigned Offs = RetAI.getDirectOffset()) { 2428 V = Builder.CreateBitCast(V, Builder.getInt8PtrTy()); 2429 V = Builder.CreateConstGEP1_32(Builder.getInt8Ty(), V, Offs); 2430 V = Builder.CreateBitCast(V, 2431 llvm::PointerType::getUnqual(RetAI.getCoerceToType())); 2432 Align = Align.alignmentAtOffset(CharUnits::fromQuantity(Offs)); 2433 } 2434 2435 RV = CreateCoercedLoad(V, RetAI.getCoerceToType(), Align, *this); 2436 } 2437 2438 // In ARC, end functions that return a retainable type with a call 2439 // to objc_autoreleaseReturnValue. 2440 if (AutoreleaseResult) { 2441 assert(getLangOpts().ObjCAutoRefCount && 2442 !FI.isReturnsRetained() && 2443 RetTy->isObjCRetainableType()); 2444 RV = emitAutoreleaseOfResult(*this, RV); 2445 } 2446 2447 break; 2448 2449 case ABIArgInfo::Ignore: 2450 break; 2451 2452 case ABIArgInfo::Expand: 2453 llvm_unreachable("Invalid ABI kind for return argument"); 2454 } 2455 2456 llvm::Instruction *Ret; 2457 if (RV) { 2458 if (SanOpts.has(SanitizerKind::ReturnsNonnullAttribute)) { 2459 if (auto RetNNAttr = CurGD.getDecl()->getAttr<ReturnsNonNullAttr>()) { 2460 SanitizerScope SanScope(this); 2461 llvm::Value *Cond = Builder.CreateICmpNE( 2462 RV, llvm::Constant::getNullValue(RV->getType())); 2463 llvm::Constant *StaticData[] = { 2464 EmitCheckSourceLocation(EndLoc), 2465 EmitCheckSourceLocation(RetNNAttr->getLocation()), 2466 }; 2467 EmitCheck(std::make_pair(Cond, SanitizerKind::ReturnsNonnullAttribute), 2468 "nonnull_return", StaticData, None); 2469 } 2470 } 2471 Ret = Builder.CreateRet(RV); 2472 } else { 2473 Ret = Builder.CreateRetVoid(); 2474 } 2475 2476 if (RetDbgLoc) 2477 Ret->setDebugLoc(std::move(RetDbgLoc)); 2478} 2479 2480static bool isInAllocaArgument(CGCXXABI &ABI, QualType type) { 2481 const CXXRecordDecl *RD = type->getAsCXXRecordDecl(); 2482 return RD && ABI.getRecordArgABI(RD) == CGCXXABI::RAA_DirectInMemory; 2483} 2484 2485static AggValueSlot createPlaceholderSlot(CodeGenFunction &CGF, QualType Ty) { 2486 // FIXME: Generate IR in one pass, rather than going back and fixing up these 2487 // placeholders. 2488 llvm::Type *IRTy = CGF.ConvertTypeForMem(Ty); 2489 llvm::Value *Placeholder = 2490 llvm::UndefValue::get(IRTy->getPointerTo()->getPointerTo()); 2491 Placeholder = CGF.Builder.CreateLoad(Placeholder); 2492 return AggValueSlot::forAddr(Placeholder, CharUnits::Zero(), 2493 Ty.getQualifiers(), 2494 AggValueSlot::IsNotDestructed, 2495 AggValueSlot::DoesNotNeedGCBarriers, 2496 AggValueSlot::IsNotAliased); 2497} 2498 2499void CodeGenFunction::EmitDelegateCallArg(CallArgList &args, 2500 const VarDecl *param, 2501 SourceLocation loc) { 2502 // StartFunction converted the ABI-lowered parameter(s) into a 2503 // local alloca. We need to turn that into an r-value suitable 2504 // for EmitCall. 2505 llvm::Value *local = GetAddrOfLocalVar(param); 2506 2507 QualType type = param->getType(); 2508 2509 // For the most part, we just need to load the alloca, except: 2510 // 1) aggregate r-values are actually pointers to temporaries, and 2511 // 2) references to non-scalars are pointers directly to the aggregate. 2512 // I don't know why references to scalars are different here. 2513 if (const ReferenceType *ref = type->getAs<ReferenceType>()) { 2514 if (!hasScalarEvaluationKind(ref->getPointeeType())) 2515 return args.add(RValue::getAggregate(local), type); 2516 2517 // Locals which are references to scalars are represented 2518 // with allocas holding the pointer. 2519 return args.add(RValue::get(Builder.CreateLoad(local)), type); 2520 } 2521 2522 assert(!isInAllocaArgument(CGM.getCXXABI(), type) && 2523 "cannot emit delegate call arguments for inalloca arguments!"); 2524 2525 args.add(convertTempToRValue(local, type, loc), type); 2526} 2527 2528static bool isProvablyNull(llvm::Value *addr) { 2529 return isa<llvm::ConstantPointerNull>(addr); 2530} 2531 2532static bool isProvablyNonNull(llvm::Value *addr) { 2533 return isa<llvm::AllocaInst>(addr); 2534} 2535 2536/// Emit the actual writing-back of a writeback. 2537static void emitWriteback(CodeGenFunction &CGF, 2538 const CallArgList::Writeback &writeback) { 2539 const LValue &srcLV = writeback.Source; 2540 llvm::Value *srcAddr = srcLV.getAddress(); 2541 assert(!isProvablyNull(srcAddr) && 2542 "shouldn't have writeback for provably null argument"); 2543 2544 llvm::BasicBlock *contBB = nullptr; 2545 2546 // If the argument wasn't provably non-null, we need to null check 2547 // before doing the store. 2548 bool provablyNonNull = isProvablyNonNull(srcAddr); 2549 if (!provablyNonNull) { 2550 llvm::BasicBlock *writebackBB = CGF.createBasicBlock("icr.writeback"); 2551 contBB = CGF.createBasicBlock("icr.done"); 2552 2553 llvm::Value *isNull = CGF.Builder.CreateIsNull(srcAddr, "icr.isnull"); 2554 CGF.Builder.CreateCondBr(isNull, contBB, writebackBB); 2555 CGF.EmitBlock(writebackBB); 2556 } 2557 2558 // Load the value to writeback. 2559 llvm::Value *value = CGF.Builder.CreateLoad(writeback.Temporary); 2560 2561 // Cast it back, in case we're writing an id to a Foo* or something. 2562 value = CGF.Builder.CreateBitCast(value, 2563 cast<llvm::PointerType>(srcAddr->getType())->getElementType(), 2564 "icr.writeback-cast"); 2565 2566 // Perform the writeback. 2567 2568 // If we have a "to use" value, it's something we need to emit a use 2569 // of. This has to be carefully threaded in: if it's done after the 2570 // release it's potentially undefined behavior (and the optimizer 2571 // will ignore it), and if it happens before the retain then the 2572 // optimizer could move the release there. 2573 if (writeback.ToUse) { 2574 assert(srcLV.getObjCLifetime() == Qualifiers::OCL_Strong); 2575 2576 // Retain the new value. No need to block-copy here: the block's 2577 // being passed up the stack. 2578 value = CGF.EmitARCRetainNonBlock(value); 2579 2580 // Emit the intrinsic use here. 2581 CGF.EmitARCIntrinsicUse(writeback.ToUse); 2582 2583 // Load the old value (primitively). 2584 llvm::Value *oldValue = CGF.EmitLoadOfScalar(srcLV, SourceLocation()); 2585 2586 // Put the new value in place (primitively). 2587 CGF.EmitStoreOfScalar(value, srcLV, /*init*/ false); 2588 2589 // Release the old value. 2590 CGF.EmitARCRelease(oldValue, srcLV.isARCPreciseLifetime()); 2591 2592 // Otherwise, we can just do a normal lvalue store. 2593 } else { 2594 CGF.EmitStoreThroughLValue(RValue::get(value), srcLV); 2595 } 2596 2597 // Jump to the continuation block. 2598 if (!provablyNonNull) 2599 CGF.EmitBlock(contBB); 2600} 2601 2602static void emitWritebacks(CodeGenFunction &CGF, 2603 const CallArgList &args) { 2604 for (const auto &I : args.writebacks()) 2605 emitWriteback(CGF, I); 2606} 2607 2608static void deactivateArgCleanupsBeforeCall(CodeGenFunction &CGF, 2609 const CallArgList &CallArgs) { 2610 assert(CGF.getTarget().getCXXABI().areArgsDestroyedLeftToRightInCallee()); 2611 ArrayRef<CallArgList::CallArgCleanup> Cleanups = 2612 CallArgs.getCleanupsToDeactivate(); 2613 // Iterate in reverse to increase the likelihood of popping the cleanup. 2614 for (ArrayRef<CallArgList::CallArgCleanup>::reverse_iterator 2615 I = Cleanups.rbegin(), E = Cleanups.rend(); I != E; ++I) { 2616 CGF.DeactivateCleanupBlock(I->Cleanup, I->IsActiveIP); 2617 I->IsActiveIP->eraseFromParent(); 2618 } 2619} 2620 2621static const Expr *maybeGetUnaryAddrOfOperand(const Expr *E) { 2622 if (const UnaryOperator *uop = dyn_cast<UnaryOperator>(E->IgnoreParens())) 2623 if (uop->getOpcode() == UO_AddrOf) 2624 return uop->getSubExpr(); 2625 return nullptr; 2626} 2627 2628/// Emit an argument that's being passed call-by-writeback. That is, 2629/// we are passing the address of 2630static void emitWritebackArg(CodeGenFunction &CGF, CallArgList &args, 2631 const ObjCIndirectCopyRestoreExpr *CRE) { 2632 LValue srcLV; 2633 2634 // Make an optimistic effort to emit the address as an l-value. 2635 // This can fail if the argument expression is more complicated. 2636 if (const Expr *lvExpr = maybeGetUnaryAddrOfOperand(CRE->getSubExpr())) { 2637 srcLV = CGF.EmitLValue(lvExpr); 2638 2639 // Otherwise, just emit it as a scalar. 2640 } else { 2641 llvm::Value *srcAddr = CGF.EmitScalarExpr(CRE->getSubExpr()); 2642 2643 QualType srcAddrType = 2644 CRE->getSubExpr()->getType()->castAs<PointerType>()->getPointeeType(); 2645 srcLV = CGF.MakeNaturalAlignAddrLValue(srcAddr, srcAddrType); 2646 } 2647 llvm::Value *srcAddr = srcLV.getAddress(); 2648 2649 // The dest and src types don't necessarily match in LLVM terms 2650 // because of the crazy ObjC compatibility rules. 2651 2652 llvm::PointerType *destType = 2653 cast<llvm::PointerType>(CGF.ConvertType(CRE->getType())); 2654 2655 // If the address is a constant null, just pass the appropriate null. 2656 if (isProvablyNull(srcAddr)) { 2657 args.add(RValue::get(llvm::ConstantPointerNull::get(destType)), 2658 CRE->getType()); 2659 return; 2660 } 2661 2662 // Create the temporary. 2663 llvm::Value *temp = CGF.CreateTempAlloca(destType->getElementType(), 2664 "icr.temp"); 2665 // Loading an l-value can introduce a cleanup if the l-value is __weak, 2666 // and that cleanup will be conditional if we can't prove that the l-value 2667 // isn't null, so we need to register a dominating point so that the cleanups 2668 // system will make valid IR. 2669 CodeGenFunction::ConditionalEvaluation condEval(CGF); 2670 2671 // Zero-initialize it if we're not doing a copy-initialization. 2672 bool shouldCopy = CRE->shouldCopy(); 2673 if (!shouldCopy) { 2674 llvm::Value *null = 2675 llvm::ConstantPointerNull::get( 2676 cast<llvm::PointerType>(destType->getElementType())); 2677 CGF.Builder.CreateStore(null, temp); 2678 } 2679 2680 llvm::BasicBlock *contBB = nullptr; 2681 llvm::BasicBlock *originBB = nullptr; 2682 2683 // If the address is *not* known to be non-null, we need to switch. 2684 llvm::Value *finalArgument; 2685 2686 bool provablyNonNull = isProvablyNonNull(srcAddr); 2687 if (provablyNonNull) { 2688 finalArgument = temp; 2689 } else { 2690 llvm::Value *isNull = CGF.Builder.CreateIsNull(srcAddr, "icr.isnull"); 2691 2692 finalArgument = CGF.Builder.CreateSelect(isNull, 2693 llvm::ConstantPointerNull::get(destType), 2694 temp, "icr.argument"); 2695 2696 // If we need to copy, then the load has to be conditional, which 2697 // means we need control flow. 2698 if (shouldCopy) { 2699 originBB = CGF.Builder.GetInsertBlock(); 2700 contBB = CGF.createBasicBlock("icr.cont"); 2701 llvm::BasicBlock *copyBB = CGF.createBasicBlock("icr.copy"); 2702 CGF.Builder.CreateCondBr(isNull, contBB, copyBB); 2703 CGF.EmitBlock(copyBB); 2704 condEval.begin(CGF); 2705 } 2706 } 2707 2708 llvm::Value *valueToUse = nullptr; 2709 2710 // Perform a copy if necessary. 2711 if (shouldCopy) { 2712 RValue srcRV = CGF.EmitLoadOfLValue(srcLV, SourceLocation()); 2713 assert(srcRV.isScalar()); 2714 2715 llvm::Value *src = srcRV.getScalarVal(); 2716 src = CGF.Builder.CreateBitCast(src, destType->getElementType(), 2717 "icr.cast"); 2718 2719 // Use an ordinary store, not a store-to-lvalue. 2720 CGF.Builder.CreateStore(src, temp); 2721 2722 // If optimization is enabled, and the value was held in a 2723 // __strong variable, we need to tell the optimizer that this 2724 // value has to stay alive until we're doing the store back. 2725 // This is because the temporary is effectively unretained, 2726 // and so otherwise we can violate the high-level semantics. 2727 if (CGF.CGM.getCodeGenOpts().OptimizationLevel != 0 && 2728 srcLV.getObjCLifetime() == Qualifiers::OCL_Strong) { 2729 valueToUse = src; 2730 } 2731 } 2732 2733 // Finish the control flow if we needed it. 2734 if (shouldCopy && !provablyNonNull) { 2735 llvm::BasicBlock *copyBB = CGF.Builder.GetInsertBlock(); 2736 CGF.EmitBlock(contBB); 2737 2738 // Make a phi for the value to intrinsically use. 2739 if (valueToUse) { 2740 llvm::PHINode *phiToUse = CGF.Builder.CreatePHI(valueToUse->getType(), 2, 2741 "icr.to-use"); 2742 phiToUse->addIncoming(valueToUse, copyBB); 2743 phiToUse->addIncoming(llvm::UndefValue::get(valueToUse->getType()), 2744 originBB); 2745 valueToUse = phiToUse; 2746 } 2747 2748 condEval.end(CGF); 2749 } 2750 2751 args.addWriteback(srcLV, temp, valueToUse); 2752 args.add(RValue::get(finalArgument), CRE->getType()); 2753} 2754 2755void CallArgList::allocateArgumentMemory(CodeGenFunction &CGF) { 2756 assert(!StackBase && !StackCleanup.isValid()); 2757 2758 // Save the stack. 2759 llvm::Function *F = CGF.CGM.getIntrinsic(llvm::Intrinsic::stacksave); 2760 StackBase = CGF.Builder.CreateCall(F, {}, "inalloca.save"); 2761 2762 // Control gets really tied up in landing pads, so we have to spill the 2763 // stacksave to an alloca to avoid violating SSA form. 2764 // TODO: This is dead if we never emit the cleanup. We should create the 2765 // alloca and store lazily on the first cleanup emission. 2766 StackBaseMem = CGF.CreateTempAlloca(CGF.Int8PtrTy, "inalloca.spmem"); 2767 CGF.Builder.CreateStore(StackBase, StackBaseMem); 2768 CGF.pushStackRestore(EHCleanup, StackBaseMem); 2769 StackCleanup = CGF.EHStack.getInnermostEHScope(); 2770 assert(StackCleanup.isValid()); 2771} 2772 2773void CallArgList::freeArgumentMemory(CodeGenFunction &CGF) const { 2774 if (StackBase) { 2775 CGF.DeactivateCleanupBlock(StackCleanup, StackBase); 2776 llvm::Value *F = CGF.CGM.getIntrinsic(llvm::Intrinsic::stackrestore); 2777 // We could load StackBase from StackBaseMem, but in the non-exceptional 2778 // case we can skip it. 2779 CGF.Builder.CreateCall(F, StackBase); 2780 } 2781} 2782 2783void CodeGenFunction::EmitNonNullArgCheck(RValue RV, QualType ArgType, 2784 SourceLocation ArgLoc, 2785 const FunctionDecl *FD, 2786 unsigned ParmNum) { 2787 if (!SanOpts.has(SanitizerKind::NonnullAttribute) || !FD) 2788 return; 2789 auto PVD = ParmNum < FD->getNumParams() ? FD->getParamDecl(ParmNum) : nullptr; 2790 unsigned ArgNo = PVD ? PVD->getFunctionScopeIndex() : ParmNum; 2791 auto NNAttr = getNonNullAttr(FD, PVD, ArgType, ArgNo); 2792 if (!NNAttr) 2793 return; 2794 SanitizerScope SanScope(this); 2795 assert(RV.isScalar()); 2796 llvm::Value *V = RV.getScalarVal(); 2797 llvm::Value *Cond = 2798 Builder.CreateICmpNE(V, llvm::Constant::getNullValue(V->getType())); 2799 llvm::Constant *StaticData[] = { 2800 EmitCheckSourceLocation(ArgLoc), 2801 EmitCheckSourceLocation(NNAttr->getLocation()), 2802 llvm::ConstantInt::get(Int32Ty, ArgNo + 1), 2803 }; 2804 EmitCheck(std::make_pair(Cond, SanitizerKind::NonnullAttribute), 2805 "nonnull_arg", StaticData, None); 2806} 2807 2808void CodeGenFunction::EmitCallArgs(CallArgList &Args, 2809 ArrayRef<QualType> ArgTypes, 2810 CallExpr::const_arg_iterator ArgBeg, 2811 CallExpr::const_arg_iterator ArgEnd, 2812 const FunctionDecl *CalleeDecl, 2813 unsigned ParamsToSkip) { 2814 // We *have* to evaluate arguments from right to left in the MS C++ ABI, 2815 // because arguments are destroyed left to right in the callee. 2816 if (CGM.getTarget().getCXXABI().areArgsDestroyedLeftToRightInCallee()) { 2817 // Insert a stack save if we're going to need any inalloca args. 2818 bool HasInAllocaArgs = false; 2819 for (ArrayRef<QualType>::iterator I = ArgTypes.begin(), E = ArgTypes.end(); 2820 I != E && !HasInAllocaArgs; ++I) 2821 HasInAllocaArgs = isInAllocaArgument(CGM.getCXXABI(), *I); 2822 if (HasInAllocaArgs) { 2823 assert(getTarget().getTriple().getArch() == llvm::Triple::x86); 2824 Args.allocateArgumentMemory(*this); 2825 } 2826 2827 // Evaluate each argument. 2828 size_t CallArgsStart = Args.size(); 2829 for (int I = ArgTypes.size() - 1; I >= 0; --I) { 2830 CallExpr::const_arg_iterator Arg = ArgBeg + I; 2831 EmitCallArg(Args, *Arg, ArgTypes[I]); 2832 EmitNonNullArgCheck(Args.back().RV, ArgTypes[I], Arg->getExprLoc(), 2833 CalleeDecl, ParamsToSkip + I); 2834 } 2835 2836 // Un-reverse the arguments we just evaluated so they match up with the LLVM 2837 // IR function. 2838 std::reverse(Args.begin() + CallArgsStart, Args.end()); 2839 return; 2840 } 2841 2842 for (unsigned I = 0, E = ArgTypes.size(); I != E; ++I) { 2843 CallExpr::const_arg_iterator Arg = ArgBeg + I; 2844 assert(Arg != ArgEnd); 2845 EmitCallArg(Args, *Arg, ArgTypes[I]); 2846 EmitNonNullArgCheck(Args.back().RV, ArgTypes[I], Arg->getExprLoc(), 2847 CalleeDecl, ParamsToSkip + I); 2848 } 2849} 2850 2851namespace { 2852 2853struct DestroyUnpassedArg : EHScopeStack::Cleanup { 2854 DestroyUnpassedArg(llvm::Value *Addr, QualType Ty) 2855 : Addr(Addr), Ty(Ty) {} 2856 2857 llvm::Value *Addr; 2858 QualType Ty; 2859 2860 void Emit(CodeGenFunction &CGF, Flags flags) override { 2861 const CXXDestructorDecl *Dtor = Ty->getAsCXXRecordDecl()->getDestructor(); 2862 assert(!Dtor->isTrivial()); 2863 CGF.EmitCXXDestructorCall(Dtor, Dtor_Complete, /*for vbase*/ false, 2864 /*Delegating=*/false, Addr); 2865 } 2866}; 2867 2868} 2869 2870struct DisableDebugLocationUpdates { 2871 CodeGenFunction &CGF; 2872 bool disabledDebugInfo; 2873 DisableDebugLocationUpdates(CodeGenFunction &CGF, const Expr *E) : CGF(CGF) { 2874 if ((disabledDebugInfo = isa<CXXDefaultArgExpr>(E) && CGF.getDebugInfo())) 2875 CGF.disableDebugInfo(); 2876 } 2877 ~DisableDebugLocationUpdates() { 2878 if (disabledDebugInfo) 2879 CGF.enableDebugInfo(); 2880 } 2881}; 2882 2883void CodeGenFunction::EmitCallArg(CallArgList &args, const Expr *E, 2884 QualType type) { 2885 DisableDebugLocationUpdates Dis(*this, E); 2886 if (const ObjCIndirectCopyRestoreExpr *CRE 2887 = dyn_cast<ObjCIndirectCopyRestoreExpr>(E)) { 2888 assert(getLangOpts().ObjCAutoRefCount); 2889 assert(getContext().hasSameType(E->getType(), type)); 2890 return emitWritebackArg(*this, args, CRE); 2891 } 2892 2893 assert(type->isReferenceType() == E->isGLValue() && 2894 "reference binding to unmaterialized r-value!"); 2895 2896 if (E->isGLValue()) { 2897 assert(E->getObjectKind() == OK_Ordinary); 2898 return args.add(EmitReferenceBindingToExpr(E), type); 2899 } 2900 2901 bool HasAggregateEvalKind = hasAggregateEvaluationKind(type); 2902 2903 // In the Microsoft C++ ABI, aggregate arguments are destructed by the callee. 2904 // However, we still have to push an EH-only cleanup in case we unwind before 2905 // we make it to the call. 2906 if (HasAggregateEvalKind && 2907 CGM.getTarget().getCXXABI().areArgsDestroyedLeftToRightInCallee()) { 2908 // If we're using inalloca, use the argument memory. Otherwise, use a 2909 // temporary. 2910 AggValueSlot Slot; 2911 if (args.isUsingInAlloca()) 2912 Slot = createPlaceholderSlot(*this, type); 2913 else 2914 Slot = CreateAggTemp(type, "agg.tmp"); 2915 2916 const CXXRecordDecl *RD = type->getAsCXXRecordDecl(); 2917 bool DestroyedInCallee = 2918 RD && RD->hasNonTrivialDestructor() && 2919 CGM.getCXXABI().getRecordArgABI(RD) != CGCXXABI::RAA_Default; 2920 if (DestroyedInCallee) 2921 Slot.setExternallyDestructed(); 2922 2923 EmitAggExpr(E, Slot); 2924 RValue RV = Slot.asRValue(); 2925 args.add(RV, type); 2926 2927 if (DestroyedInCallee) { 2928 // Create a no-op GEP between the placeholder and the cleanup so we can 2929 // RAUW it successfully. It also serves as a marker of the first 2930 // instruction where the cleanup is active. 2931 pushFullExprCleanup<DestroyUnpassedArg>(EHCleanup, Slot.getAddr(), type); 2932 // This unreachable is a temporary marker which will be removed later. 2933 llvm::Instruction *IsActive = Builder.CreateUnreachable(); 2934 args.addArgCleanupDeactivation(EHStack.getInnermostEHScope(), IsActive); 2935 } 2936 return; 2937 } 2938 2939 if (HasAggregateEvalKind && isa<ImplicitCastExpr>(E) && 2940 cast<CastExpr>(E)->getCastKind() == CK_LValueToRValue) { 2941 LValue L = EmitLValue(cast<CastExpr>(E)->getSubExpr()); 2942 assert(L.isSimple()); 2943 if (L.getAlignment() >= getContext().getTypeAlignInChars(type)) { 2944 args.add(L.asAggregateRValue(), type, /*NeedsCopy*/true); 2945 } else { 2946 // We can't represent a misaligned lvalue in the CallArgList, so copy 2947 // to an aligned temporary now. 2948 llvm::Value *tmp = CreateMemTemp(type); 2949 EmitAggregateCopy(tmp, L.getAddress(), type, L.isVolatile(), 2950 L.getAlignment()); 2951 args.add(RValue::getAggregate(tmp), type); 2952 } 2953 return; 2954 } 2955 2956 args.add(EmitAnyExprToTemp(E), type); 2957} 2958 2959QualType CodeGenFunction::getVarArgType(const Expr *Arg) { 2960 // System headers on Windows define NULL to 0 instead of 0LL on Win64. MSVC 2961 // implicitly widens null pointer constants that are arguments to varargs 2962 // functions to pointer-sized ints. 2963 if (!getTarget().getTriple().isOSWindows()) 2964 return Arg->getType(); 2965 2966 if (Arg->getType()->isIntegerType() && 2967 getContext().getTypeSize(Arg->getType()) < 2968 getContext().getTargetInfo().getPointerWidth(0) && 2969 Arg->isNullPointerConstant(getContext(), 2970 Expr::NPC_ValueDependentIsNotNull)) { 2971 return getContext().getIntPtrType(); 2972 } 2973 2974 return Arg->getType(); 2975} 2976 2977// In ObjC ARC mode with no ObjC ARC exception safety, tell the ARC 2978// optimizer it can aggressively ignore unwind edges. 2979void 2980CodeGenFunction::AddObjCARCExceptionMetadata(llvm::Instruction *Inst) { 2981 if (CGM.getCodeGenOpts().OptimizationLevel != 0 && 2982 !CGM.getCodeGenOpts().ObjCAutoRefCountExceptions) 2983 Inst->setMetadata("clang.arc.no_objc_arc_exceptions", 2984 CGM.getNoObjCARCExceptionsMetadata()); 2985} 2986 2987/// Emits a call to the given no-arguments nounwind runtime function. 2988llvm::CallInst * 2989CodeGenFunction::EmitNounwindRuntimeCall(llvm::Value *callee, 2990 const llvm::Twine &name) { 2991 return EmitNounwindRuntimeCall(callee, None, name); 2992} 2993 2994/// Emits a call to the given nounwind runtime function. 2995llvm::CallInst * 2996CodeGenFunction::EmitNounwindRuntimeCall(llvm::Value *callee, 2997 ArrayRef<llvm::Value*> args, 2998 const llvm::Twine &name) { 2999 llvm::CallInst *call = EmitRuntimeCall(callee, args, name); 3000 call->setDoesNotThrow(); 3001 return call; 3002} 3003 3004/// Emits a simple call (never an invoke) to the given no-arguments 3005/// runtime function. 3006llvm::CallInst * 3007CodeGenFunction::EmitRuntimeCall(llvm::Value *callee, 3008 const llvm::Twine &name) { 3009 return EmitRuntimeCall(callee, None, name); 3010} 3011 3012/// Emits a simple call (never an invoke) to the given runtime 3013/// function. 3014llvm::CallInst * 3015CodeGenFunction::EmitRuntimeCall(llvm::Value *callee, 3016 ArrayRef<llvm::Value*> args, 3017 const llvm::Twine &name) { 3018 llvm::CallInst *call = Builder.CreateCall(callee, args, name); 3019 call->setCallingConv(getRuntimeCC()); 3020 return call; 3021} 3022 3023/// Emits a call or invoke to the given noreturn runtime function. 3024void CodeGenFunction::EmitNoreturnRuntimeCallOrInvoke(llvm::Value *callee, 3025 ArrayRef<llvm::Value*> args) { 3026 if (getInvokeDest()) { 3027 llvm::InvokeInst *invoke = 3028 Builder.CreateInvoke(callee, 3029 getUnreachableBlock(), 3030 getInvokeDest(), 3031 args); 3032 invoke->setDoesNotReturn(); 3033 invoke->setCallingConv(getRuntimeCC()); 3034 } else { 3035 llvm::CallInst *call = Builder.CreateCall(callee, args); 3036 call->setDoesNotReturn(); 3037 call->setCallingConv(getRuntimeCC()); 3038 Builder.CreateUnreachable(); 3039 } 3040} 3041 3042/// Emits a call or invoke instruction to the given nullary runtime 3043/// function. 3044llvm::CallSite 3045CodeGenFunction::EmitRuntimeCallOrInvoke(llvm::Value *callee, 3046 const Twine &name) { 3047 return EmitRuntimeCallOrInvoke(callee, None, name); 3048} 3049 3050/// Emits a call or invoke instruction to the given runtime function. 3051llvm::CallSite 3052CodeGenFunction::EmitRuntimeCallOrInvoke(llvm::Value *callee, 3053 ArrayRef<llvm::Value*> args, 3054 const Twine &name) { 3055 llvm::CallSite callSite = EmitCallOrInvoke(callee, args, name); 3056 callSite.setCallingConv(getRuntimeCC()); 3057 return callSite; 3058} 3059 3060llvm::CallSite 3061CodeGenFunction::EmitCallOrInvoke(llvm::Value *Callee, 3062 const Twine &Name) { 3063 return EmitCallOrInvoke(Callee, None, Name); 3064} 3065 3066/// Emits a call or invoke instruction to the given function, depending 3067/// on the current state of the EH stack. 3068llvm::CallSite 3069CodeGenFunction::EmitCallOrInvoke(llvm::Value *Callee, 3070 ArrayRef<llvm::Value *> Args, 3071 const Twine &Name) { 3072 llvm::BasicBlock *InvokeDest = getInvokeDest(); 3073 3074 llvm::Instruction *Inst; 3075 if (!InvokeDest) 3076 Inst = Builder.CreateCall(Callee, Args, Name); 3077 else { 3078 llvm::BasicBlock *ContBB = createBasicBlock("invoke.cont"); 3079 Inst = Builder.CreateInvoke(Callee, ContBB, InvokeDest, Args, Name); 3080 EmitBlock(ContBB); 3081 } 3082 3083 // In ObjC ARC mode with no ObjC ARC exception safety, tell the ARC 3084 // optimizer it can aggressively ignore unwind edges. 3085 if (CGM.getLangOpts().ObjCAutoRefCount) 3086 AddObjCARCExceptionMetadata(Inst); 3087 3088 return llvm::CallSite(Inst); 3089} 3090 3091/// \brief Store a non-aggregate value to an address to initialize it. For 3092/// initialization, a non-atomic store will be used. 3093static void EmitInitStoreOfNonAggregate(CodeGenFunction &CGF, RValue Src, 3094 LValue Dst) { 3095 if (Src.isScalar()) 3096 CGF.EmitStoreOfScalar(Src.getScalarVal(), Dst, /*init=*/true); 3097 else 3098 CGF.EmitStoreOfComplex(Src.getComplexVal(), Dst, /*init=*/true); 3099} 3100 3101void CodeGenFunction::deferPlaceholderReplacement(llvm::Instruction *Old, 3102 llvm::Value *New) { 3103 DeferredReplacements.push_back(std::make_pair(Old, New)); 3104} 3105 3106RValue CodeGenFunction::EmitCall(const CGFunctionInfo &CallInfo, 3107 llvm::Value *Callee, 3108 ReturnValueSlot ReturnValue, 3109 const CallArgList &CallArgs, 3110 const Decl *TargetDecl, 3111 llvm::Instruction **callOrInvoke) { 3112 // FIXME: We no longer need the types from CallArgs; lift up and simplify. 3113 3114 // Handle struct-return functions by passing a pointer to the 3115 // location that we would like to return into. 3116 QualType RetTy = CallInfo.getReturnType(); 3117 const ABIArgInfo &RetAI = CallInfo.getReturnInfo(); 3118 3119 llvm::FunctionType *IRFuncTy = 3120 cast<llvm::FunctionType>( 3121 cast<llvm::PointerType>(Callee->getType())->getElementType()); 3122 3123 // If we're using inalloca, insert the allocation after the stack save. 3124 // FIXME: Do this earlier rather than hacking it in here! 3125 llvm::AllocaInst *ArgMemory = nullptr; 3126 if (llvm::StructType *ArgStruct = CallInfo.getArgStruct()) { 3127 llvm::Instruction *IP = CallArgs.getStackBase(); 3128 llvm::AllocaInst *AI; 3129 if (IP) { 3130 IP = IP->getNextNode(); 3131 AI = new llvm::AllocaInst(ArgStruct, "argmem", IP); 3132 } else { 3133 AI = CreateTempAlloca(ArgStruct, "argmem"); 3134 } 3135 AI->setUsedWithInAlloca(true); 3136 assert(AI->isUsedWithInAlloca() && !AI->isStaticAlloca()); 3137 ArgMemory = AI; 3138 } 3139 3140 ClangToLLVMArgMapping IRFunctionArgs(CGM.getContext(), CallInfo); 3141 SmallVector<llvm::Value *, 16> IRCallArgs(IRFunctionArgs.totalIRArgs()); 3142 3143 // If the call returns a temporary with struct return, create a temporary 3144 // alloca to hold the result, unless one is given to us. 3145 llvm::Value *SRetPtr = nullptr; 3146 size_t UnusedReturnSize = 0; 3147 if (RetAI.isIndirect() || RetAI.isInAlloca()) { 3148 SRetPtr = ReturnValue.getValue(); 3149 if (!SRetPtr) { 3150 SRetPtr = CreateMemTemp(RetTy); 3151 if (HaveInsertPoint() && ReturnValue.isUnused()) { 3152 uint64_t size = 3153 CGM.getDataLayout().getTypeAllocSize(ConvertTypeForMem(RetTy)); 3154 if (EmitLifetimeStart(size, SRetPtr)) 3155 UnusedReturnSize = size; 3156 } 3157 } 3158 if (IRFunctionArgs.hasSRetArg()) { 3159 IRCallArgs[IRFunctionArgs.getSRetArgNo()] = SRetPtr; 3160 } else { 3161 llvm::Value *Addr = 3162 Builder.CreateStructGEP(ArgMemory->getAllocatedType(), ArgMemory, 3163 RetAI.getInAllocaFieldIndex()); 3164 Builder.CreateStore(SRetPtr, Addr); 3165 } 3166 } 3167 3168 assert(CallInfo.arg_size() == CallArgs.size() && 3169 "Mismatch between function signature & arguments."); 3170 unsigned ArgNo = 0; 3171 CGFunctionInfo::const_arg_iterator info_it = CallInfo.arg_begin(); 3172 for (CallArgList::const_iterator I = CallArgs.begin(), E = CallArgs.end(); 3173 I != E; ++I, ++info_it, ++ArgNo) { 3174 const ABIArgInfo &ArgInfo = info_it->info; 3175 RValue RV = I->RV; 3176 3177 CharUnits TypeAlign = getContext().getTypeAlignInChars(I->Ty); 3178 3179 // Insert a padding argument to ensure proper alignment. 3180 if (IRFunctionArgs.hasPaddingArg(ArgNo)) 3181 IRCallArgs[IRFunctionArgs.getPaddingArgNo(ArgNo)] = 3182 llvm::UndefValue::get(ArgInfo.getPaddingType()); 3183 3184 unsigned FirstIRArg, NumIRArgs; 3185 std::tie(FirstIRArg, NumIRArgs) = IRFunctionArgs.getIRArgs(ArgNo); 3186 3187 switch (ArgInfo.getKind()) { 3188 case ABIArgInfo::InAlloca: { 3189 assert(NumIRArgs == 0); 3190 assert(getTarget().getTriple().getArch() == llvm::Triple::x86); 3191 if (RV.isAggregate()) { 3192 // Replace the placeholder with the appropriate argument slot GEP. 3193 llvm::Instruction *Placeholder = 3194 cast<llvm::Instruction>(RV.getAggregateAddr()); 3195 CGBuilderTy::InsertPoint IP = Builder.saveIP(); 3196 Builder.SetInsertPoint(Placeholder); 3197 llvm::Value *Addr = 3198 Builder.CreateStructGEP(ArgMemory->getAllocatedType(), ArgMemory, 3199 ArgInfo.getInAllocaFieldIndex()); 3200 Builder.restoreIP(IP); 3201 deferPlaceholderReplacement(Placeholder, Addr); 3202 } else { 3203 // Store the RValue into the argument struct. 3204 llvm::Value *Addr = 3205 Builder.CreateStructGEP(ArgMemory->getAllocatedType(), ArgMemory, 3206 ArgInfo.getInAllocaFieldIndex()); 3207 unsigned AS = Addr->getType()->getPointerAddressSpace(); 3208 llvm::Type *MemType = ConvertTypeForMem(I->Ty)->getPointerTo(AS); 3209 // There are some cases where a trivial bitcast is not avoidable. The 3210 // definition of a type later in a translation unit may change it's type 3211 // from {}* to (%struct.foo*)*. 3212 if (Addr->getType() != MemType) 3213 Addr = Builder.CreateBitCast(Addr, MemType); 3214 LValue argLV = MakeAddrLValue(Addr, I->Ty, TypeAlign); 3215 EmitInitStoreOfNonAggregate(*this, RV, argLV); 3216 } 3217 break; 3218 } 3219 3220 case ABIArgInfo::Indirect: { 3221 assert(NumIRArgs == 1); 3222 if (RV.isScalar() || RV.isComplex()) { 3223 // Make a temporary alloca to pass the argument. 3224 llvm::AllocaInst *AI = CreateMemTemp(I->Ty); 3225 if (ArgInfo.getIndirectAlign() > AI->getAlignment()) 3226 AI->setAlignment(ArgInfo.getIndirectAlign()); 3227 IRCallArgs[FirstIRArg] = AI; 3228 3229 LValue argLV = MakeAddrLValue(AI, I->Ty, TypeAlign); 3230 EmitInitStoreOfNonAggregate(*this, RV, argLV); 3231 } else { 3232 // We want to avoid creating an unnecessary temporary+copy here; 3233 // however, we need one in three cases: 3234 // 1. If the argument is not byval, and we are required to copy the 3235 // source. (This case doesn't occur on any common architecture.) 3236 // 2. If the argument is byval, RV is not sufficiently aligned, and 3237 // we cannot force it to be sufficiently aligned. 3238 // 3. If the argument is byval, but RV is located in an address space 3239 // different than that of the argument (0). 3240 llvm::Value *Addr = RV.getAggregateAddr(); 3241 unsigned Align = ArgInfo.getIndirectAlign(); 3242 const llvm::DataLayout *TD = &CGM.getDataLayout(); 3243 const unsigned RVAddrSpace = Addr->getType()->getPointerAddressSpace(); 3244 const unsigned ArgAddrSpace = 3245 (FirstIRArg < IRFuncTy->getNumParams() 3246 ? IRFuncTy->getParamType(FirstIRArg)->getPointerAddressSpace() 3247 : 0); 3248 if ((!ArgInfo.getIndirectByVal() && I->NeedsCopy) || 3249 (ArgInfo.getIndirectByVal() && TypeAlign.getQuantity() < Align && 3250 llvm::getOrEnforceKnownAlignment(Addr, Align, *TD) < Align) || 3251 (ArgInfo.getIndirectByVal() && (RVAddrSpace != ArgAddrSpace))) { 3252 // Create an aligned temporary, and copy to it. 3253 llvm::AllocaInst *AI = CreateMemTemp(I->Ty); 3254 if (Align > AI->getAlignment()) 3255 AI->setAlignment(Align); 3256 IRCallArgs[FirstIRArg] = AI; 3257 EmitAggregateCopy(AI, Addr, I->Ty, RV.isVolatileQualified()); 3258 } else { 3259 // Skip the extra memcpy call. 3260 IRCallArgs[FirstIRArg] = Addr; 3261 } 3262 } 3263 break; 3264 } 3265 3266 case ABIArgInfo::Ignore: 3267 assert(NumIRArgs == 0); 3268 break; 3269 3270 case ABIArgInfo::Extend: 3271 case ABIArgInfo::Direct: { 3272 if (!isa<llvm::StructType>(ArgInfo.getCoerceToType()) && 3273 ArgInfo.getCoerceToType() == ConvertType(info_it->type) && 3274 ArgInfo.getDirectOffset() == 0) { 3275 assert(NumIRArgs == 1); 3276 llvm::Value *V; 3277 if (RV.isScalar()) 3278 V = RV.getScalarVal(); 3279 else 3280 V = Builder.CreateLoad(RV.getAggregateAddr()); 3281 3282 // We might have to widen integers, but we should never truncate. 3283 if (ArgInfo.getCoerceToType() != V->getType() && 3284 V->getType()->isIntegerTy()) 3285 V = Builder.CreateZExt(V, ArgInfo.getCoerceToType()); 3286 3287 // If the argument doesn't match, perform a bitcast to coerce it. This 3288 // can happen due to trivial type mismatches. 3289 if (FirstIRArg < IRFuncTy->getNumParams() && 3290 V->getType() != IRFuncTy->getParamType(FirstIRArg)) 3291 V = Builder.CreateBitCast(V, IRFuncTy->getParamType(FirstIRArg)); 3292 IRCallArgs[FirstIRArg] = V; 3293 break; 3294 } 3295 3296 // FIXME: Avoid the conversion through memory if possible. 3297 llvm::Value *SrcPtr; 3298 CharUnits SrcAlign; 3299 if (RV.isScalar() || RV.isComplex()) { 3300 SrcPtr = CreateMemTemp(I->Ty, "coerce"); 3301 SrcAlign = TypeAlign; 3302 LValue SrcLV = MakeAddrLValue(SrcPtr, I->Ty, TypeAlign); 3303 EmitInitStoreOfNonAggregate(*this, RV, SrcLV); 3304 } else { 3305 SrcPtr = RV.getAggregateAddr(); 3306 // This alignment is guaranteed by EmitCallArg. 3307 SrcAlign = TypeAlign; 3308 } 3309 3310 // If the value is offset in memory, apply the offset now. 3311 if (unsigned Offs = ArgInfo.getDirectOffset()) { 3312 SrcPtr = Builder.CreateBitCast(SrcPtr, Builder.getInt8PtrTy()); 3313 SrcPtr = Builder.CreateConstGEP1_32(Builder.getInt8Ty(), SrcPtr, Offs); 3314 SrcPtr = Builder.CreateBitCast(SrcPtr, 3315 llvm::PointerType::getUnqual(ArgInfo.getCoerceToType())); 3316 SrcAlign = SrcAlign.alignmentAtOffset(CharUnits::fromQuantity(Offs)); 3317 } 3318 3319 // Fast-isel and the optimizer generally like scalar values better than 3320 // FCAs, so we flatten them if this is safe to do for this argument. 3321 llvm::StructType *STy = 3322 dyn_cast<llvm::StructType>(ArgInfo.getCoerceToType()); 3323 if (STy && ArgInfo.isDirect() && ArgInfo.getCanBeFlattened()) { 3324 llvm::Type *SrcTy = 3325 cast<llvm::PointerType>(SrcPtr->getType())->getElementType(); 3326 uint64_t SrcSize = CGM.getDataLayout().getTypeAllocSize(SrcTy); 3327 uint64_t DstSize = CGM.getDataLayout().getTypeAllocSize(STy); 3328 3329 // If the source type is smaller than the destination type of the 3330 // coerce-to logic, copy the source value into a temp alloca the size 3331 // of the destination type to allow loading all of it. The bits past 3332 // the source value are left undef. 3333 if (SrcSize < DstSize) { 3334 llvm::AllocaInst *TempAlloca 3335 = CreateTempAlloca(STy, SrcPtr->getName() + ".coerce"); 3336 Builder.CreateMemCpy(TempAlloca, SrcPtr, SrcSize, 0); 3337 SrcPtr = TempAlloca; 3338 } else { 3339 SrcPtr = Builder.CreateBitCast(SrcPtr, 3340 llvm::PointerType::getUnqual(STy)); 3341 } 3342 3343 assert(NumIRArgs == STy->getNumElements()); 3344 for (unsigned i = 0, e = STy->getNumElements(); i != e; ++i) { 3345 llvm::Value *EltPtr = Builder.CreateConstGEP2_32(STy, SrcPtr, 0, i); 3346 llvm::LoadInst *LI = Builder.CreateLoad(EltPtr); 3347 // We don't know what we're loading from. 3348 LI->setAlignment(1); 3349 IRCallArgs[FirstIRArg + i] = LI; 3350 } 3351 } else { 3352 // In the simple case, just pass the coerced loaded value. 3353 assert(NumIRArgs == 1); 3354 IRCallArgs[FirstIRArg] = 3355 CreateCoercedLoad(SrcPtr, ArgInfo.getCoerceToType(), 3356 SrcAlign, *this); 3357 } 3358 3359 break; 3360 } 3361 3362 case ABIArgInfo::Expand: 3363 unsigned IRArgPos = FirstIRArg; 3364 ExpandTypeToArgs(I->Ty, RV, IRFuncTy, IRCallArgs, IRArgPos); 3365 assert(IRArgPos == FirstIRArg + NumIRArgs); 3366 break; 3367 } 3368 } 3369 3370 if (ArgMemory) { 3371 llvm::Value *Arg = ArgMemory; 3372 if (CallInfo.isVariadic()) { 3373 // When passing non-POD arguments by value to variadic functions, we will 3374 // end up with a variadic prototype and an inalloca call site. In such 3375 // cases, we can't do any parameter mismatch checks. Give up and bitcast 3376 // the callee. 3377 unsigned CalleeAS = 3378 cast<llvm::PointerType>(Callee->getType())->getAddressSpace(); 3379 Callee = Builder.CreateBitCast( 3380 Callee, getTypes().GetFunctionType(CallInfo)->getPointerTo(CalleeAS)); 3381 } else { 3382 llvm::Type *LastParamTy = 3383 IRFuncTy->getParamType(IRFuncTy->getNumParams() - 1); 3384 if (Arg->getType() != LastParamTy) { 3385#ifndef NDEBUG 3386 // Assert that these structs have equivalent element types. 3387 llvm::StructType *FullTy = CallInfo.getArgStruct(); 3388 llvm::StructType *DeclaredTy = cast<llvm::StructType>( 3389 cast<llvm::PointerType>(LastParamTy)->getElementType()); 3390 assert(DeclaredTy->getNumElements() == FullTy->getNumElements()); 3391 for (llvm::StructType::element_iterator DI = DeclaredTy->element_begin(), 3392 DE = DeclaredTy->element_end(), 3393 FI = FullTy->element_begin(); 3394 DI != DE; ++DI, ++FI) 3395 assert(*DI == *FI); 3396#endif 3397 Arg = Builder.CreateBitCast(Arg, LastParamTy); 3398 } 3399 } 3400 assert(IRFunctionArgs.hasInallocaArg()); 3401 IRCallArgs[IRFunctionArgs.getInallocaArgNo()] = Arg; 3402 } 3403 3404 if (!CallArgs.getCleanupsToDeactivate().empty()) 3405 deactivateArgCleanupsBeforeCall(*this, CallArgs); 3406 3407 // If the callee is a bitcast of a function to a varargs pointer to function 3408 // type, check to see if we can remove the bitcast. This handles some cases 3409 // with unprototyped functions. 3410 if (llvm::ConstantExpr *CE = dyn_cast<llvm::ConstantExpr>(Callee)) 3411 if (llvm::Function *CalleeF = dyn_cast<llvm::Function>(CE->getOperand(0))) { 3412 llvm::PointerType *CurPT=cast<llvm::PointerType>(Callee->getType()); 3413 llvm::FunctionType *CurFT = 3414 cast<llvm::FunctionType>(CurPT->getElementType()); 3415 llvm::FunctionType *ActualFT = CalleeF->getFunctionType(); 3416 3417 if (CE->getOpcode() == llvm::Instruction::BitCast && 3418 ActualFT->getReturnType() == CurFT->getReturnType() && 3419 ActualFT->getNumParams() == CurFT->getNumParams() && 3420 ActualFT->getNumParams() == IRCallArgs.size() && 3421 (CurFT->isVarArg() || !ActualFT->isVarArg())) { 3422 bool ArgsMatch = true; 3423 for (unsigned i = 0, e = ActualFT->getNumParams(); i != e; ++i) 3424 if (ActualFT->getParamType(i) != CurFT->getParamType(i)) { 3425 ArgsMatch = false; 3426 break; 3427 } 3428 3429 // Strip the cast if we can get away with it. This is a nice cleanup, 3430 // but also allows us to inline the function at -O0 if it is marked 3431 // always_inline. 3432 if (ArgsMatch) 3433 Callee = CalleeF; 3434 } 3435 } 3436 3437 assert(IRCallArgs.size() == IRFuncTy->getNumParams() || IRFuncTy->isVarArg()); 3438 for (unsigned i = 0; i < IRCallArgs.size(); ++i) { 3439 // Inalloca argument can have different type. 3440 if (IRFunctionArgs.hasInallocaArg() && 3441 i == IRFunctionArgs.getInallocaArgNo()) 3442 continue; 3443 if (i < IRFuncTy->getNumParams()) 3444 assert(IRCallArgs[i]->getType() == IRFuncTy->getParamType(i)); 3445 } 3446 3447 unsigned CallingConv; 3448 CodeGen::AttributeListType AttributeList; 3449 CGM.ConstructAttributeList(CallInfo, TargetDecl, AttributeList, 3450 CallingConv, true); 3451 llvm::AttributeSet Attrs = llvm::AttributeSet::get(getLLVMContext(), 3452 AttributeList); 3453 3454 llvm::BasicBlock *InvokeDest = nullptr; 3455 if (!Attrs.hasAttribute(llvm::AttributeSet::FunctionIndex, 3456 llvm::Attribute::NoUnwind) || 3457 currentFunctionUsesSEHTry()) 3458 InvokeDest = getInvokeDest(); 3459 3460 llvm::CallSite CS; 3461 if (!InvokeDest) { 3462 CS = Builder.CreateCall(Callee, IRCallArgs); 3463 } else { 3464 llvm::BasicBlock *Cont = createBasicBlock("invoke.cont"); 3465 CS = Builder.CreateInvoke(Callee, Cont, InvokeDest, IRCallArgs); 3466 EmitBlock(Cont); 3467 } 3468 if (callOrInvoke) 3469 *callOrInvoke = CS.getInstruction(); 3470 3471 if (CurCodeDecl && CurCodeDecl->hasAttr<FlattenAttr>() && 3472 !CS.hasFnAttr(llvm::Attribute::NoInline)) 3473 Attrs = 3474 Attrs.addAttribute(getLLVMContext(), llvm::AttributeSet::FunctionIndex, 3475 llvm::Attribute::AlwaysInline); 3476 3477 // Disable inlining inside SEH __try blocks. 3478 if (isSEHTryScope()) 3479 Attrs = 3480 Attrs.addAttribute(getLLVMContext(), llvm::AttributeSet::FunctionIndex, 3481 llvm::Attribute::NoInline); 3482 3483 CS.setAttributes(Attrs); 3484 CS.setCallingConv(static_cast<llvm::CallingConv::ID>(CallingConv)); 3485 3486 // In ObjC ARC mode with no ObjC ARC exception safety, tell the ARC 3487 // optimizer it can aggressively ignore unwind edges. 3488 if (CGM.getLangOpts().ObjCAutoRefCount) 3489 AddObjCARCExceptionMetadata(CS.getInstruction()); 3490 3491 // If the call doesn't return, finish the basic block and clear the 3492 // insertion point; this allows the rest of IRgen to discard 3493 // unreachable code. 3494 if (CS.doesNotReturn()) { 3495 if (UnusedReturnSize) 3496 EmitLifetimeEnd(llvm::ConstantInt::get(Int64Ty, UnusedReturnSize), 3497 SRetPtr); 3498 3499 Builder.CreateUnreachable(); 3500 Builder.ClearInsertionPoint(); 3501 3502 // FIXME: For now, emit a dummy basic block because expr emitters in 3503 // generally are not ready to handle emitting expressions at unreachable 3504 // points. 3505 EnsureInsertPoint(); 3506 3507 // Return a reasonable RValue. 3508 return GetUndefRValue(RetTy); 3509 } 3510 3511 llvm::Instruction *CI = CS.getInstruction(); 3512 if (Builder.isNamePreserving() && !CI->getType()->isVoidTy()) 3513 CI->setName("call"); 3514 3515 // Emit any writebacks immediately. Arguably this should happen 3516 // after any return-value munging. 3517 if (CallArgs.hasWritebacks()) 3518 emitWritebacks(*this, CallArgs); 3519 3520 // The stack cleanup for inalloca arguments has to run out of the normal 3521 // lexical order, so deactivate it and run it manually here. 3522 CallArgs.freeArgumentMemory(*this); 3523 3524 RValue Ret = [&] { 3525 switch (RetAI.getKind()) { 3526 case ABIArgInfo::InAlloca: 3527 case ABIArgInfo::Indirect: { 3528 RValue ret = convertTempToRValue(SRetPtr, RetTy, SourceLocation()); 3529 if (UnusedReturnSize) 3530 EmitLifetimeEnd(llvm::ConstantInt::get(Int64Ty, UnusedReturnSize), 3531 SRetPtr); 3532 return ret; 3533 } 3534 3535 case ABIArgInfo::Ignore: 3536 // If we are ignoring an argument that had a result, make sure to 3537 // construct the appropriate return value for our caller. 3538 return GetUndefRValue(RetTy); 3539 3540 case ABIArgInfo::Extend: 3541 case ABIArgInfo::Direct: { 3542 llvm::Type *RetIRTy = ConvertType(RetTy); 3543 if (RetAI.getCoerceToType() == RetIRTy && RetAI.getDirectOffset() == 0) { 3544 switch (getEvaluationKind(RetTy)) { 3545 case TEK_Complex: { 3546 llvm::Value *Real = Builder.CreateExtractValue(CI, 0); 3547 llvm::Value *Imag = Builder.CreateExtractValue(CI, 1); 3548 return RValue::getComplex(std::make_pair(Real, Imag)); 3549 } 3550 case TEK_Aggregate: { 3551 llvm::Value *DestPtr = ReturnValue.getValue(); 3552 bool DestIsVolatile = ReturnValue.isVolatile(); 3553 CharUnits DestAlign = getContext().getTypeAlignInChars(RetTy); 3554 3555 if (!DestPtr) { 3556 DestPtr = CreateMemTemp(RetTy, "agg.tmp"); 3557 DestIsVolatile = false; 3558 } 3559 BuildAggStore(*this, CI, DestPtr, DestIsVolatile, DestAlign); 3560 return RValue::getAggregate(DestPtr); 3561 } 3562 case TEK_Scalar: { 3563 // If the argument doesn't match, perform a bitcast to coerce it. This 3564 // can happen due to trivial type mismatches. 3565 llvm::Value *V = CI; 3566 if (V->getType() != RetIRTy) 3567 V = Builder.CreateBitCast(V, RetIRTy); 3568 return RValue::get(V); 3569 } 3570 } 3571 llvm_unreachable("bad evaluation kind"); 3572 } 3573 3574 llvm::Value *DestPtr = ReturnValue.getValue(); 3575 bool DestIsVolatile = ReturnValue.isVolatile(); 3576 CharUnits DestAlign = getContext().getTypeAlignInChars(RetTy); 3577 3578 if (!DestPtr) { 3579 DestPtr = CreateMemTemp(RetTy, "coerce"); 3580 DestIsVolatile = false; 3581 } 3582 3583 // If the value is offset in memory, apply the offset now. 3584 llvm::Value *StorePtr = DestPtr; 3585 CharUnits StoreAlign = DestAlign; 3586 if (unsigned Offs = RetAI.getDirectOffset()) { 3587 StorePtr = Builder.CreateBitCast(StorePtr, Builder.getInt8PtrTy()); 3588 StorePtr = 3589 Builder.CreateConstGEP1_32(Builder.getInt8Ty(), StorePtr, Offs); 3590 StorePtr = Builder.CreateBitCast(StorePtr, 3591 llvm::PointerType::getUnqual(RetAI.getCoerceToType())); 3592 StoreAlign = 3593 StoreAlign.alignmentAtOffset(CharUnits::fromQuantity(Offs)); 3594 } 3595 CreateCoercedStore(CI, StorePtr, DestIsVolatile, StoreAlign, *this); 3596 3597 return convertTempToRValue(DestPtr, RetTy, SourceLocation()); 3598 } 3599 3600 case ABIArgInfo::Expand: 3601 llvm_unreachable("Invalid ABI kind for return argument"); 3602 } 3603 3604 llvm_unreachable("Unhandled ABIArgInfo::Kind"); 3605 } (); 3606 3607 if (Ret.isScalar() && TargetDecl) { 3608 if (const auto *AA = TargetDecl->getAttr<AssumeAlignedAttr>()) { 3609 llvm::Value *OffsetValue = nullptr; 3610 if (const auto *Offset = AA->getOffset()) 3611 OffsetValue = EmitScalarExpr(Offset); 3612 3613 llvm::Value *Alignment = EmitScalarExpr(AA->getAlignment()); 3614 llvm::ConstantInt *AlignmentCI = cast<llvm::ConstantInt>(Alignment); 3615 EmitAlignmentAssumption(Ret.getScalarVal(), AlignmentCI->getZExtValue(), 3616 OffsetValue); 3617 } 3618 } 3619 3620 return Ret; 3621} 3622 3623/* VarArg handling */ 3624 3625llvm::Value *CodeGenFunction::EmitVAArg(llvm::Value *VAListAddr, QualType Ty) { 3626 return CGM.getTypes().getABIInfo().EmitVAArg(VAListAddr, Ty, *this); 3627} 3628