Anders Carlsson | 046c294 | 2010-04-17 20:15:18 +0000 | [diff] [blame] | 1 | //===--- CGVTables.cpp - Emit LLVM Code for C++ vtables -------------------===// |
Anders Carlsson | dbd920c | 2009-10-11 22:13:54 +0000 | [diff] [blame] | 2 | // |
| 3 | // The LLVM Compiler Infrastructure |
| 4 | // |
| 5 | // This file is distributed under the University of Illinois Open Source |
| 6 | // License. See LICENSE.TXT for details. |
| 7 | // |
| 8 | //===----------------------------------------------------------------------===// |
| 9 | // |
| 10 | // This contains code dealing with C++ code generation of virtual tables. |
| 11 | // |
| 12 | //===----------------------------------------------------------------------===// |
| 13 | |
Anders Carlsson | dbd920c | 2009-10-11 22:13:54 +0000 | [diff] [blame] | 14 | #include "CodeGenFunction.h" |
John McCall | 4c40d98 | 2010-08-31 07:33:07 +0000 | [diff] [blame] | 15 | #include "CGCXXABI.h" |
Chandler Carruth | 55fc873 | 2012-12-04 09:13:33 +0000 | [diff] [blame] | 16 | #include "CodeGenModule.h" |
Anders Carlsson | d6b07fb | 2009-11-27 20:47:55 +0000 | [diff] [blame] | 17 | #include "clang/AST/CXXInheritance.h" |
Anders Carlsson | dbd920c | 2009-10-11 22:13:54 +0000 | [diff] [blame] | 18 | #include "clang/AST/RecordLayout.h" |
Mark Lacey | 8b54999 | 2013-10-30 21:53:58 +0000 | [diff] [blame] | 19 | #include "clang/CodeGen/CGFunctionInfo.h" |
John McCall | 7a53690 | 2010-08-05 20:39:18 +0000 | [diff] [blame] | 20 | #include "clang/Frontend/CodeGenOptions.h" |
Anders Carlsson | 5dd730a | 2009-11-26 19:32:45 +0000 | [diff] [blame] | 21 | #include "llvm/ADT/DenseSet.h" |
Anders Carlsson | b9021e9 | 2010-02-27 16:18:19 +0000 | [diff] [blame] | 22 | #include "llvm/ADT/SetVector.h" |
Chandler Carruth | e087f07 | 2010-02-13 10:38:52 +0000 | [diff] [blame] | 23 | #include "llvm/Support/Compiler.h" |
Anders Carlsson | 824d7ea | 2010-02-11 08:02:13 +0000 | [diff] [blame] | 24 | #include "llvm/Support/Format.h" |
Eli Friedman | 7dcdf5b | 2011-05-06 17:27:27 +0000 | [diff] [blame] | 25 | #include "llvm/Transforms/Utils/Cloning.h" |
Anders Carlsson | 5e454aa | 2010-03-17 20:06:32 +0000 | [diff] [blame] | 26 | #include <algorithm> |
Zhongxing Xu | 7fe26ac | 2009-11-13 05:46:16 +0000 | [diff] [blame] | 27 | #include <cstdio> |
Anders Carlsson | dbd920c | 2009-10-11 22:13:54 +0000 | [diff] [blame] | 28 | |
| 29 | using namespace clang; |
| 30 | using namespace CodeGen; |
| 31 | |
Peter Collingbourne | 1d2b317 | 2011-09-26 01:56:30 +0000 | [diff] [blame] | 32 | CodeGenVTables::CodeGenVTables(CodeGenModule &CGM) |
Stephen Hines | 651f13c | 2014-04-23 16:59:28 -0700 | [diff] [blame] | 33 | : CGM(CGM), VTContext(CGM.getContext().getVTableContext()) {} |
Peter Collingbourne | 1d2b317 | 2011-09-26 01:56:30 +0000 | [diff] [blame] | 34 | |
Anders Carlsson | 19879c9 | 2010-03-23 17:17:29 +0000 | [diff] [blame] | 35 | llvm::Constant *CodeGenModule::GetAddrOfThunk(GlobalDecl GD, |
Anders Carlsson | 84c49e4 | 2011-02-06 17:15:43 +0000 | [diff] [blame] | 36 | const ThunkInfo &Thunk) { |
Anders Carlsson | 19879c9 | 2010-03-23 17:17:29 +0000 | [diff] [blame] | 37 | const CXXMethodDecl *MD = cast<CXXMethodDecl>(GD.getDecl()); |
| 38 | |
| 39 | // Compute the mangled name. |
Dylan Noblesmith | f7ccbad | 2012-02-05 02:13:05 +0000 | [diff] [blame] | 40 | SmallString<256> Name; |
Rafael Espindola | f0be979 | 2011-02-11 02:52:17 +0000 | [diff] [blame] | 41 | llvm::raw_svector_ostream Out(Name); |
Anders Carlsson | 19879c9 | 2010-03-23 17:17:29 +0000 | [diff] [blame] | 42 | if (const CXXDestructorDecl* DD = dyn_cast<CXXDestructorDecl>(MD)) |
John McCall | 4c40d98 | 2010-08-31 07:33:07 +0000 | [diff] [blame] | 43 | getCXXABI().getMangleContext().mangleCXXDtorThunk(DD, GD.getDtorType(), |
Rafael Espindola | f0be979 | 2011-02-11 02:52:17 +0000 | [diff] [blame] | 44 | Thunk.This, Out); |
Anders Carlsson | 19879c9 | 2010-03-23 17:17:29 +0000 | [diff] [blame] | 45 | else |
Rafael Espindola | f0be979 | 2011-02-11 02:52:17 +0000 | [diff] [blame] | 46 | getCXXABI().getMangleContext().mangleThunk(MD, Thunk, Out); |
Rafael Espindola | f0be979 | 2011-02-11 02:52:17 +0000 | [diff] [blame] | 47 | |
Chris Lattner | 2acc6e3 | 2011-07-18 04:24:23 +0000 | [diff] [blame] | 48 | llvm::Type *Ty = getTypes().GetFunctionTypeForVTable(GD); |
Stephen Hines | 651f13c | 2014-04-23 16:59:28 -0700 | [diff] [blame] | 49 | return GetOrCreateLLVMFunction(Name, Ty, GD, /*ForVTable=*/true, |
Stephen Hines | 176edba | 2014-12-01 14:53:08 -0800 | [diff] [blame] | 50 | /*DontDefer=*/true, /*IsThunk=*/true); |
Anders Carlsson | 19879c9 | 2010-03-23 17:17:29 +0000 | [diff] [blame] | 51 | } |
| 52 | |
John McCall | 6500553 | 2010-08-04 23:46:35 +0000 | [diff] [blame] | 53 | static void setThunkVisibility(CodeGenModule &CGM, const CXXMethodDecl *MD, |
| 54 | const ThunkInfo &Thunk, llvm::Function *Fn) { |
Anders Carlsson | 0ffeaad | 2011-01-29 19:39:23 +0000 | [diff] [blame] | 55 | CGM.setGlobalVisibility(Fn, MD); |
John McCall | 6500553 | 2010-08-04 23:46:35 +0000 | [diff] [blame] | 56 | } |
| 57 | |
Pirama Arumuga Nainar | 87d948e | 2016-03-03 15:49:35 -0800 | [diff] [blame] | 58 | static void setThunkProperties(CodeGenModule &CGM, const ThunkInfo &Thunk, |
| 59 | llvm::Function *ThunkFn, bool ForVTable, |
| 60 | GlobalDecl GD) { |
| 61 | CGM.setFunctionLinkage(GD, ThunkFn); |
| 62 | CGM.getCXXABI().setThunkLinkage(ThunkFn, ForVTable, GD, |
| 63 | !Thunk.Return.isEmpty()); |
| 64 | |
| 65 | // Set the right visibility. |
| 66 | const CXXMethodDecl *MD = cast<CXXMethodDecl>(GD.getDecl()); |
| 67 | setThunkVisibility(CGM, MD, Thunk, ThunkFn); |
| 68 | |
| 69 | if (CGM.supportsCOMDAT() && ThunkFn->isWeakForLinker()) |
| 70 | ThunkFn->setComdat(CGM.getModule().getOrInsertComdat(ThunkFn->getName())); |
| 71 | } |
| 72 | |
John McCall | 311b442 | 2011-03-09 07:12:35 +0000 | [diff] [blame] | 73 | #ifndef NDEBUG |
| 74 | static bool similar(const ABIArgInfo &infoL, CanQualType typeL, |
| 75 | const ABIArgInfo &infoR, CanQualType typeR) { |
| 76 | return (infoL.getKind() == infoR.getKind() && |
| 77 | (typeL == typeR || |
| 78 | (isa<PointerType>(typeL) && isa<PointerType>(typeR)) || |
| 79 | (isa<ReferenceType>(typeL) && isa<ReferenceType>(typeR)))); |
| 80 | } |
| 81 | #endif |
| 82 | |
Eli Friedman | 7dcdf5b | 2011-05-06 17:27:27 +0000 | [diff] [blame] | 83 | static RValue PerformReturnAdjustment(CodeGenFunction &CGF, |
| 84 | QualType ResultType, RValue RV, |
| 85 | const ThunkInfo &Thunk) { |
| 86 | // Emit the return adjustment. |
| 87 | bool NullCheckValue = !ResultType->isReferenceType(); |
Stephen Hines | 6bcf27b | 2014-05-29 04:14:42 -0700 | [diff] [blame] | 88 | |
| 89 | llvm::BasicBlock *AdjustNull = nullptr; |
| 90 | llvm::BasicBlock *AdjustNotNull = nullptr; |
| 91 | llvm::BasicBlock *AdjustEnd = nullptr; |
| 92 | |
Eli Friedman | 7dcdf5b | 2011-05-06 17:27:27 +0000 | [diff] [blame] | 93 | llvm::Value *ReturnValue = RV.getScalarVal(); |
| 94 | |
| 95 | if (NullCheckValue) { |
| 96 | AdjustNull = CGF.createBasicBlock("adjust.null"); |
| 97 | AdjustNotNull = CGF.createBasicBlock("adjust.notnull"); |
| 98 | AdjustEnd = CGF.createBasicBlock("adjust.end"); |
| 99 | |
| 100 | llvm::Value *IsNull = CGF.Builder.CreateIsNull(ReturnValue); |
| 101 | CGF.Builder.CreateCondBr(IsNull, AdjustNull, AdjustNotNull); |
| 102 | CGF.EmitBlock(AdjustNotNull); |
| 103 | } |
Timur Iskhodzhanov | c70cc5d | 2013-10-30 11:55:43 +0000 | [diff] [blame] | 104 | |
Pirama Arumuga Nainar | 87d948e | 2016-03-03 15:49:35 -0800 | [diff] [blame] | 105 | auto ClassDecl = ResultType->getPointeeType()->getAsCXXRecordDecl(); |
| 106 | auto ClassAlign = CGF.CGM.getClassPointerAlignment(ClassDecl); |
| 107 | ReturnValue = CGF.CGM.getCXXABI().performReturnAdjustment(CGF, |
| 108 | Address(ReturnValue, ClassAlign), |
| 109 | Thunk.Return); |
Timur Iskhodzhanov | c70cc5d | 2013-10-30 11:55:43 +0000 | [diff] [blame] | 110 | |
Eli Friedman | 7dcdf5b | 2011-05-06 17:27:27 +0000 | [diff] [blame] | 111 | if (NullCheckValue) { |
| 112 | CGF.Builder.CreateBr(AdjustEnd); |
| 113 | CGF.EmitBlock(AdjustNull); |
| 114 | CGF.Builder.CreateBr(AdjustEnd); |
| 115 | CGF.EmitBlock(AdjustEnd); |
| 116 | |
| 117 | llvm::PHINode *PHI = CGF.Builder.CreatePHI(ReturnValue->getType(), 2); |
| 118 | PHI->addIncoming(ReturnValue, AdjustNotNull); |
| 119 | PHI->addIncoming(llvm::Constant::getNullValue(ReturnValue->getType()), |
| 120 | AdjustNull); |
| 121 | ReturnValue = PHI; |
| 122 | } |
| 123 | |
| 124 | return RValue::get(ReturnValue); |
| 125 | } |
| 126 | |
| 127 | // This function does roughly the same thing as GenerateThunk, but in a |
| 128 | // very different way, so that va_start and va_end work correctly. |
| 129 | // FIXME: This function assumes "this" is the first non-sret LLVM argument of |
| 130 | // a function, and that there is an alloca built in the entry block |
| 131 | // for all accesses to "this". |
| 132 | // FIXME: This function assumes there is only one "ret" statement per function. |
| 133 | // FIXME: Cloning isn't correct in the presence of indirect goto! |
| 134 | // FIXME: This implementation of thunks bloats codesize by duplicating the |
| 135 | // function definition. There are alternatives: |
| 136 | // 1. Add some sort of stub support to LLVM for cases where we can |
| 137 | // do a this adjustment, then a sibcall. |
| 138 | // 2. We could transform the definition to take a va_list instead of an |
| 139 | // actual variable argument list, then have the thunks (including a |
| 140 | // no-op thunk for the regular definition) call va_start/va_end. |
| 141 | // There's a bit of per-call overhead for this solution, but it's |
| 142 | // better for codesize if the definition is long. |
Pirama Arumuga Nainar | 87d948e | 2016-03-03 15:49:35 -0800 | [diff] [blame] | 143 | llvm::Function * |
| 144 | CodeGenFunction::GenerateVarArgsThunk(llvm::Function *Fn, |
Eli Friedman | 7dcdf5b | 2011-05-06 17:27:27 +0000 | [diff] [blame] | 145 | const CGFunctionInfo &FnInfo, |
| 146 | GlobalDecl GD, const ThunkInfo &Thunk) { |
| 147 | const CXXMethodDecl *MD = cast<CXXMethodDecl>(GD.getDecl()); |
| 148 | const FunctionProtoType *FPT = MD->getType()->getAs<FunctionProtoType>(); |
Stephen Hines | 651f13c | 2014-04-23 16:59:28 -0700 | [diff] [blame] | 149 | QualType ResultType = FPT->getReturnType(); |
Eli Friedman | 7dcdf5b | 2011-05-06 17:27:27 +0000 | [diff] [blame] | 150 | |
| 151 | // Get the original function |
John McCall | de5d3c7 | 2012-02-17 03:33:10 +0000 | [diff] [blame] | 152 | assert(FnInfo.isVariadic()); |
| 153 | llvm::Type *Ty = CGM.getTypes().GetFunctionType(FnInfo); |
Eli Friedman | 7dcdf5b | 2011-05-06 17:27:27 +0000 | [diff] [blame] | 154 | llvm::Value *Callee = CGM.GetAddrOfFunction(GD, Ty, /*ForVTable=*/true); |
| 155 | llvm::Function *BaseFn = cast<llvm::Function>(Callee); |
| 156 | |
| 157 | // Clone to thunk. |
Benjamin Kramer | 9b5ede5 | 2012-09-19 13:13:52 +0000 | [diff] [blame] | 158 | llvm::ValueToValueMapTy VMap; |
Pirama Arumuga Nainar | 4967a71 | 2016-09-19 22:19:55 -0700 | [diff] [blame^] | 159 | llvm::Function *NewFn = llvm::CloneFunction(BaseFn, VMap); |
Eli Friedman | 7dcdf5b | 2011-05-06 17:27:27 +0000 | [diff] [blame] | 160 | Fn->replaceAllUsesWith(NewFn); |
| 161 | NewFn->takeName(Fn); |
| 162 | Fn->eraseFromParent(); |
| 163 | Fn = NewFn; |
| 164 | |
| 165 | // "Initialize" CGF (minimally). |
| 166 | CurFn = Fn; |
| 167 | |
| 168 | // Get the "this" value |
| 169 | llvm::Function::arg_iterator AI = Fn->arg_begin(); |
| 170 | if (CGM.ReturnTypeUsesSRet(FnInfo)) |
| 171 | ++AI; |
| 172 | |
| 173 | // Find the first store of "this", which will be to the alloca associated |
| 174 | // with "this". |
Pirama Arumuga Nainar | 87d948e | 2016-03-03 15:49:35 -0800 | [diff] [blame] | 175 | Address ThisPtr(&*AI, CGM.getClassPointerAlignment(MD->getParent())); |
| 176 | llvm::BasicBlock *EntryBB = &Fn->front(); |
| 177 | llvm::BasicBlock::iterator ThisStore = |
Stephen Hines | 0e2c34f | 2015-03-23 12:09:02 -0700 | [diff] [blame] | 178 | std::find_if(EntryBB->begin(), EntryBB->end(), [&](llvm::Instruction &I) { |
Pirama Arumuga Nainar | 87d948e | 2016-03-03 15:49:35 -0800 | [diff] [blame] | 179 | return isa<llvm::StoreInst>(I) && |
| 180 | I.getOperand(0) == ThisPtr.getPointer(); |
| 181 | }); |
| 182 | assert(ThisStore != EntryBB->end() && |
| 183 | "Store of this should be in entry block?"); |
Eli Friedman | 7dcdf5b | 2011-05-06 17:27:27 +0000 | [diff] [blame] | 184 | // Adjust "this", if necessary. |
Pirama Arumuga Nainar | 87d948e | 2016-03-03 15:49:35 -0800 | [diff] [blame] | 185 | Builder.SetInsertPoint(&*ThisStore); |
Timur Iskhodzhanov | c70cc5d | 2013-10-30 11:55:43 +0000 | [diff] [blame] | 186 | llvm::Value *AdjustedThisPtr = |
| 187 | CGM.getCXXABI().performThisAdjustment(*this, ThisPtr, Thunk.This); |
Eli Friedman | 7dcdf5b | 2011-05-06 17:27:27 +0000 | [diff] [blame] | 188 | ThisStore->setOperand(0, AdjustedThisPtr); |
| 189 | |
| 190 | if (!Thunk.Return.isEmpty()) { |
| 191 | // Fix up the returned value, if necessary. |
Pirama Arumuga Nainar | 87d948e | 2016-03-03 15:49:35 -0800 | [diff] [blame] | 192 | for (llvm::BasicBlock &BB : *Fn) { |
| 193 | llvm::Instruction *T = BB.getTerminator(); |
Eli Friedman | 7dcdf5b | 2011-05-06 17:27:27 +0000 | [diff] [blame] | 194 | if (isa<llvm::ReturnInst>(T)) { |
| 195 | RValue RV = RValue::get(T->getOperand(0)); |
| 196 | T->eraseFromParent(); |
Pirama Arumuga Nainar | 87d948e | 2016-03-03 15:49:35 -0800 | [diff] [blame] | 197 | Builder.SetInsertPoint(&BB); |
Eli Friedman | 7dcdf5b | 2011-05-06 17:27:27 +0000 | [diff] [blame] | 198 | RV = PerformReturnAdjustment(*this, ResultType, RV, Thunk); |
| 199 | Builder.CreateRet(RV.getScalarVal()); |
| 200 | break; |
| 201 | } |
| 202 | } |
| 203 | } |
Pirama Arumuga Nainar | 87d948e | 2016-03-03 15:49:35 -0800 | [diff] [blame] | 204 | |
| 205 | return Fn; |
Eli Friedman | 7dcdf5b | 2011-05-06 17:27:27 +0000 | [diff] [blame] | 206 | } |
| 207 | |
Hans Wennborg | 93b717a | 2013-11-15 17:24:45 +0000 | [diff] [blame] | 208 | void CodeGenFunction::StartThunk(llvm::Function *Fn, GlobalDecl GD, |
| 209 | const CGFunctionInfo &FnInfo) { |
| 210 | assert(!CurGD.getDecl() && "CurGD was already set!"); |
| 211 | CurGD = GD; |
Stephen Hines | 176edba | 2014-12-01 14:53:08 -0800 | [diff] [blame] | 212 | CurFuncIsThunk = true; |
Hans Wennborg | 93b717a | 2013-11-15 17:24:45 +0000 | [diff] [blame] | 213 | |
| 214 | // Build FunctionArgs. |
Anders Carlsson | 519c328 | 2010-03-24 00:39:18 +0000 | [diff] [blame] | 215 | const CXXMethodDecl *MD = cast<CXXMethodDecl>(GD.getDecl()); |
Anders Carlsson | 519c328 | 2010-03-24 00:39:18 +0000 | [diff] [blame] | 216 | QualType ThisType = MD->getThisType(getContext()); |
Hans Wennborg | 93b717a | 2013-11-15 17:24:45 +0000 | [diff] [blame] | 217 | const FunctionProtoType *FPT = MD->getType()->getAs<FunctionProtoType>(); |
Stephen Hines | 176edba | 2014-12-01 14:53:08 -0800 | [diff] [blame] | 218 | QualType ResultType = CGM.getCXXABI().HasThisReturn(GD) |
| 219 | ? ThisType |
| 220 | : CGM.getCXXABI().hasMostDerivedReturn(GD) |
| 221 | ? CGM.getContext().VoidPtrTy |
| 222 | : FPT->getReturnType(); |
Anders Carlsson | 519c328 | 2010-03-24 00:39:18 +0000 | [diff] [blame] | 223 | FunctionArgList FunctionArgs; |
| 224 | |
Anders Carlsson | 519c328 | 2010-03-24 00:39:18 +0000 | [diff] [blame] | 225 | // Create the implicit 'this' parameter declaration. |
Stephen Hines | 651f13c | 2014-04-23 16:59:28 -0700 | [diff] [blame] | 226 | CGM.getCXXABI().buildThisParam(*this, FunctionArgs); |
Anders Carlsson | 519c328 | 2010-03-24 00:39:18 +0000 | [diff] [blame] | 227 | |
| 228 | // Add the rest of the parameters. |
Stephen Hines | 176edba | 2014-12-01 14:53:08 -0800 | [diff] [blame] | 229 | FunctionArgs.append(MD->param_begin(), MD->param_end()); |
Alexey Samsonov | 34b41f8 | 2012-10-25 10:18:50 +0000 | [diff] [blame] | 230 | |
Stephen Hines | 651f13c | 2014-04-23 16:59:28 -0700 | [diff] [blame] | 231 | if (isa<CXXDestructorDecl>(MD)) |
| 232 | CGM.getCXXABI().addImplicitStructorParams(*this, ResultType, FunctionArgs); |
| 233 | |
Hans Wennborg | 93b717a | 2013-11-15 17:24:45 +0000 | [diff] [blame] | 234 | // Start defining the function. |
John McCall | d26bc76 | 2011-03-09 04:27:21 +0000 | [diff] [blame] | 235 | StartFunction(GlobalDecl(), ResultType, Fn, FnInfo, FunctionArgs, |
Stephen Hines | 0e2c34f | 2015-03-23 12:09:02 -0700 | [diff] [blame] | 236 | MD->getLocation(), MD->getLocation()); |
Anders Carlsson | 519c328 | 2010-03-24 00:39:18 +0000 | [diff] [blame] | 237 | |
Hans Wennborg | 93b717a | 2013-11-15 17:24:45 +0000 | [diff] [blame] | 238 | // Since we didn't pass a GlobalDecl to StartFunction, do this ourselves. |
John McCall | 4c40d98 | 2010-08-31 07:33:07 +0000 | [diff] [blame] | 239 | CGM.getCXXABI().EmitInstanceFunctionProlog(*this); |
Eli Friedman | cec5ebd | 2012-02-11 02:57:39 +0000 | [diff] [blame] | 240 | CXXThisValue = CXXABIThisValue; |
Pirama Arumuga Nainar | 87d948e | 2016-03-03 15:49:35 -0800 | [diff] [blame] | 241 | CurCodeDecl = MD; |
| 242 | CurFuncDecl = MD; |
| 243 | } |
| 244 | |
| 245 | void CodeGenFunction::FinishThunk() { |
| 246 | // Clear these to restore the invariants expected by |
| 247 | // StartFunction/FinishFunction. |
| 248 | CurCodeDecl = nullptr; |
| 249 | CurFuncDecl = nullptr; |
| 250 | |
| 251 | FinishFunction(); |
Hans Wennborg | 93b717a | 2013-11-15 17:24:45 +0000 | [diff] [blame] | 252 | } |
John McCall | 4c40d98 | 2010-08-31 07:33:07 +0000 | [diff] [blame] | 253 | |
Stephen Hines | 176edba | 2014-12-01 14:53:08 -0800 | [diff] [blame] | 254 | void CodeGenFunction::EmitCallAndReturnForThunk(llvm::Value *Callee, |
Hans Wennborg | 93b717a | 2013-11-15 17:24:45 +0000 | [diff] [blame] | 255 | const ThunkInfo *Thunk) { |
| 256 | assert(isa<CXXMethodDecl>(CurGD.getDecl()) && |
| 257 | "Please use a new CGF for this thunk"); |
Stephen Hines | 176edba | 2014-12-01 14:53:08 -0800 | [diff] [blame] | 258 | const CXXMethodDecl *MD = cast<CXXMethodDecl>(CurGD.getDecl()); |
Timur Iskhodzhanov | c70cc5d | 2013-10-30 11:55:43 +0000 | [diff] [blame] | 259 | |
Hans Wennborg | 93b717a | 2013-11-15 17:24:45 +0000 | [diff] [blame] | 260 | // Adjust the 'this' pointer if necessary |
Pirama Arumuga Nainar | 87d948e | 2016-03-03 15:49:35 -0800 | [diff] [blame] | 261 | llvm::Value *AdjustedThisPtr = |
| 262 | Thunk ? CGM.getCXXABI().performThisAdjustment( |
| 263 | *this, LoadCXXThisAddress(), Thunk->This) |
| 264 | : LoadCXXThis(); |
Hans Wennborg | 93b717a | 2013-11-15 17:24:45 +0000 | [diff] [blame] | 265 | |
Stephen Hines | 176edba | 2014-12-01 14:53:08 -0800 | [diff] [blame] | 266 | if (CurFnInfo->usesInAlloca()) { |
| 267 | // We don't handle return adjusting thunks, because they require us to call |
| 268 | // the copy constructor. For now, fall through and pretend the return |
| 269 | // adjustment was empty so we don't crash. |
| 270 | if (Thunk && !Thunk->Return.isEmpty()) { |
| 271 | CGM.ErrorUnsupported( |
| 272 | MD, "non-trivial argument copy for return-adjusting thunk"); |
| 273 | } |
| 274 | EmitMustTailThunk(MD, AdjustedThisPtr, Callee); |
| 275 | return; |
| 276 | } |
| 277 | |
Hans Wennborg | 93b717a | 2013-11-15 17:24:45 +0000 | [diff] [blame] | 278 | // Start building CallArgs. |
Anders Carlsson | 519c328 | 2010-03-24 00:39:18 +0000 | [diff] [blame] | 279 | CallArgList CallArgs; |
Hans Wennborg | 93b717a | 2013-11-15 17:24:45 +0000 | [diff] [blame] | 280 | QualType ThisType = MD->getThisType(getContext()); |
Eli Friedman | 04c9a49 | 2011-05-02 17:57:46 +0000 | [diff] [blame] | 281 | CallArgs.add(RValue::get(AdjustedThisPtr), ThisType); |
Anders Carlsson | 519c328 | 2010-03-24 00:39:18 +0000 | [diff] [blame] | 282 | |
Timur Iskhodzhanov | 2cb17a0 | 2013-10-09 09:23:58 +0000 | [diff] [blame] | 283 | if (isa<CXXDestructorDecl>(MD)) |
Stephen Hines | 176edba | 2014-12-01 14:53:08 -0800 | [diff] [blame] | 284 | CGM.getCXXABI().adjustCallArgsForDestructorThunk(*this, CurGD, CallArgs); |
Timur Iskhodzhanov | 2cb17a0 | 2013-10-09 09:23:58 +0000 | [diff] [blame] | 285 | |
Hans Wennborg | 93b717a | 2013-11-15 17:24:45 +0000 | [diff] [blame] | 286 | // Add the rest of the arguments. |
Pirama Arumuga Nainar | 4967a71 | 2016-09-19 22:19:55 -0700 | [diff] [blame^] | 287 | for (const ParmVarDecl *PD : MD->parameters()) |
Stephen Hines | 176edba | 2014-12-01 14:53:08 -0800 | [diff] [blame] | 288 | EmitDelegateCallArg(CallArgs, PD, PD->getLocStart()); |
Anders Carlsson | 519c328 | 2010-03-24 00:39:18 +0000 | [diff] [blame] | 289 | |
Hans Wennborg | 93b717a | 2013-11-15 17:24:45 +0000 | [diff] [blame] | 290 | const FunctionProtoType *FPT = MD->getType()->getAs<FunctionProtoType>(); |
Anders Carlsson | 519c328 | 2010-03-24 00:39:18 +0000 | [diff] [blame] | 291 | |
John McCall | d26bc76 | 2011-03-09 04:27:21 +0000 | [diff] [blame] | 292 | #ifndef NDEBUG |
Pirama Arumuga Nainar | 4967a71 | 2016-09-19 22:19:55 -0700 | [diff] [blame^] | 293 | const CGFunctionInfo &CallFnInfo = CGM.getTypes().arrangeCXXMethodCall( |
| 294 | CallArgs, FPT, RequiredArgs::forPrototypePlus(FPT, 1, MD)); |
Hans Wennborg | 93b717a | 2013-11-15 17:24:45 +0000 | [diff] [blame] | 295 | assert(CallFnInfo.getRegParm() == CurFnInfo->getRegParm() && |
| 296 | CallFnInfo.isNoReturn() == CurFnInfo->isNoReturn() && |
| 297 | CallFnInfo.getCallingConvention() == CurFnInfo->getCallingConvention()); |
John McCall | 0f3d097 | 2012-07-07 06:41:13 +0000 | [diff] [blame] | 298 | assert(isa<CXXDestructorDecl>(MD) || // ignore dtor return types |
| 299 | similar(CallFnInfo.getReturnInfo(), CallFnInfo.getReturnType(), |
Hans Wennborg | 93b717a | 2013-11-15 17:24:45 +0000 | [diff] [blame] | 300 | CurFnInfo->getReturnInfo(), CurFnInfo->getReturnType())); |
| 301 | assert(CallFnInfo.arg_size() == CurFnInfo->arg_size()); |
| 302 | for (unsigned i = 0, e = CurFnInfo->arg_size(); i != e; ++i) |
John McCall | 311b442 | 2011-03-09 07:12:35 +0000 | [diff] [blame] | 303 | assert(similar(CallFnInfo.arg_begin()[i].info, |
| 304 | CallFnInfo.arg_begin()[i].type, |
Hans Wennborg | 93b717a | 2013-11-15 17:24:45 +0000 | [diff] [blame] | 305 | CurFnInfo->arg_begin()[i].info, |
| 306 | CurFnInfo->arg_begin()[i].type)); |
John McCall | d26bc76 | 2011-03-09 04:27:21 +0000 | [diff] [blame] | 307 | #endif |
Hans Wennborg | 93b717a | 2013-11-15 17:24:45 +0000 | [diff] [blame] | 308 | |
Douglas Gregor | cb359df | 2010-05-20 05:54:35 +0000 | [diff] [blame] | 309 | // Determine whether we have a return value slot to use. |
Stephen Hines | 176edba | 2014-12-01 14:53:08 -0800 | [diff] [blame] | 310 | QualType ResultType = CGM.getCXXABI().HasThisReturn(CurGD) |
| 311 | ? ThisType |
| 312 | : CGM.getCXXABI().hasMostDerivedReturn(CurGD) |
| 313 | ? CGM.getContext().VoidPtrTy |
| 314 | : FPT->getReturnType(); |
Douglas Gregor | cb359df | 2010-05-20 05:54:35 +0000 | [diff] [blame] | 315 | ReturnValueSlot Slot; |
| 316 | if (!ResultType->isVoidType() && |
Hans Wennborg | 93b717a | 2013-11-15 17:24:45 +0000 | [diff] [blame] | 317 | CurFnInfo->getReturnInfo().getKind() == ABIArgInfo::Indirect && |
John McCall | 9d232c8 | 2013-03-07 21:37:08 +0000 | [diff] [blame] | 318 | !hasScalarEvaluationKind(CurFnInfo->getReturnType())) |
Douglas Gregor | cb359df | 2010-05-20 05:54:35 +0000 | [diff] [blame] | 319 | Slot = ReturnValueSlot(ReturnValue, ResultType.isVolatileQualified()); |
| 320 | |
Anders Carlsson | 519c328 | 2010-03-24 00:39:18 +0000 | [diff] [blame] | 321 | // Now emit our call. |
Stephen Hines | 176edba | 2014-12-01 14:53:08 -0800 | [diff] [blame] | 322 | llvm::Instruction *CallOrInvoke; |
| 323 | RValue RV = EmitCall(*CurFnInfo, Callee, Slot, CallArgs, MD, &CallOrInvoke); |
| 324 | |
Hans Wennborg | 93b717a | 2013-11-15 17:24:45 +0000 | [diff] [blame] | 325 | // Consider return adjustment if we have ThunkInfo. |
| 326 | if (Thunk && !Thunk->Return.isEmpty()) |
| 327 | RV = PerformReturnAdjustment(*this, ResultType, RV, *Thunk); |
Pirama Arumuga Nainar | 87d948e | 2016-03-03 15:49:35 -0800 | [diff] [blame] | 328 | else if (llvm::CallInst* Call = dyn_cast<llvm::CallInst>(CallOrInvoke)) |
| 329 | Call->setTailCallKind(llvm::CallInst::TCK_Tail); |
Anders Carlsson | 519c328 | 2010-03-24 00:39:18 +0000 | [diff] [blame] | 330 | |
Hans Wennborg | 93b717a | 2013-11-15 17:24:45 +0000 | [diff] [blame] | 331 | // Emit return. |
Douglas Gregor | cb359df | 2010-05-20 05:54:35 +0000 | [diff] [blame] | 332 | if (!ResultType->isVoidType() && Slot.isNull()) |
John McCall | d16c2cf | 2011-02-08 08:22:06 +0000 | [diff] [blame] | 333 | CGM.getCXXABI().EmitReturnFromThunk(*this, RV, ResultType); |
Anders Carlsson | 519c328 | 2010-03-24 00:39:18 +0000 | [diff] [blame] | 334 | |
John McCall | bd9b65a | 2012-07-31 00:33:55 +0000 | [diff] [blame] | 335 | // Disable the final ARC autorelease. |
| 336 | AutoreleaseResult = false; |
| 337 | |
Pirama Arumuga Nainar | 87d948e | 2016-03-03 15:49:35 -0800 | [diff] [blame] | 338 | FinishThunk(); |
Hans Wennborg | 93b717a | 2013-11-15 17:24:45 +0000 | [diff] [blame] | 339 | } |
| 340 | |
Stephen Hines | 176edba | 2014-12-01 14:53:08 -0800 | [diff] [blame] | 341 | void CodeGenFunction::EmitMustTailThunk(const CXXMethodDecl *MD, |
| 342 | llvm::Value *AdjustedThisPtr, |
| 343 | llvm::Value *Callee) { |
| 344 | // Emitting a musttail call thunk doesn't use any of the CGCall.cpp machinery |
| 345 | // to translate AST arguments into LLVM IR arguments. For thunks, we know |
| 346 | // that the caller prototype more or less matches the callee prototype with |
| 347 | // the exception of 'this'. |
| 348 | SmallVector<llvm::Value *, 8> Args; |
| 349 | for (llvm::Argument &A : CurFn->args()) |
| 350 | Args.push_back(&A); |
| 351 | |
| 352 | // Set the adjusted 'this' pointer. |
| 353 | const ABIArgInfo &ThisAI = CurFnInfo->arg_begin()->info; |
| 354 | if (ThisAI.isDirect()) { |
| 355 | const ABIArgInfo &RetAI = CurFnInfo->getReturnInfo(); |
| 356 | int ThisArgNo = RetAI.isIndirect() && !RetAI.isSRetAfterThis() ? 1 : 0; |
| 357 | llvm::Type *ThisType = Args[ThisArgNo]->getType(); |
| 358 | if (ThisType != AdjustedThisPtr->getType()) |
| 359 | AdjustedThisPtr = Builder.CreateBitCast(AdjustedThisPtr, ThisType); |
| 360 | Args[ThisArgNo] = AdjustedThisPtr; |
| 361 | } else { |
| 362 | assert(ThisAI.isInAlloca() && "this is passed directly or inalloca"); |
Pirama Arumuga Nainar | 87d948e | 2016-03-03 15:49:35 -0800 | [diff] [blame] | 363 | Address ThisAddr = GetAddrOfLocalVar(CXXABIThisDecl); |
| 364 | llvm::Type *ThisType = ThisAddr.getElementType(); |
Stephen Hines | 176edba | 2014-12-01 14:53:08 -0800 | [diff] [blame] | 365 | if (ThisType != AdjustedThisPtr->getType()) |
| 366 | AdjustedThisPtr = Builder.CreateBitCast(AdjustedThisPtr, ThisType); |
| 367 | Builder.CreateStore(AdjustedThisPtr, ThisAddr); |
| 368 | } |
| 369 | |
| 370 | // Emit the musttail call manually. Even if the prologue pushed cleanups, we |
| 371 | // don't actually want to run them. |
| 372 | llvm::CallInst *Call = Builder.CreateCall(Callee, Args); |
| 373 | Call->setTailCallKind(llvm::CallInst::TCK_MustTail); |
| 374 | |
| 375 | // Apply the standard set of call attributes. |
| 376 | unsigned CallingConv; |
| 377 | CodeGen::AttributeListType AttributeList; |
Pirama Arumuga Nainar | 4967a71 | 2016-09-19 22:19:55 -0700 | [diff] [blame^] | 378 | CGM.ConstructAttributeList(Callee->getName(), *CurFnInfo, MD, AttributeList, |
| 379 | CallingConv, /*AttrOnCallSite=*/true); |
Stephen Hines | 176edba | 2014-12-01 14:53:08 -0800 | [diff] [blame] | 380 | llvm::AttributeSet Attrs = |
| 381 | llvm::AttributeSet::get(getLLVMContext(), AttributeList); |
| 382 | Call->setAttributes(Attrs); |
| 383 | Call->setCallingConv(static_cast<llvm::CallingConv::ID>(CallingConv)); |
| 384 | |
| 385 | if (Call->getType()->isVoidTy()) |
| 386 | Builder.CreateRetVoid(); |
| 387 | else |
| 388 | Builder.CreateRet(Call); |
| 389 | |
| 390 | // Finish the function to maintain CodeGenFunction invariants. |
| 391 | // FIXME: Don't emit unreachable code. |
| 392 | EmitBlock(createBasicBlock()); |
| 393 | FinishFunction(); |
| 394 | } |
| 395 | |
Pirama Arumuga Nainar | 87d948e | 2016-03-03 15:49:35 -0800 | [diff] [blame] | 396 | void CodeGenFunction::generateThunk(llvm::Function *Fn, |
Hans Wennborg | 93b717a | 2013-11-15 17:24:45 +0000 | [diff] [blame] | 397 | const CGFunctionInfo &FnInfo, |
| 398 | GlobalDecl GD, const ThunkInfo &Thunk) { |
| 399 | StartThunk(Fn, GD, FnInfo); |
| 400 | |
| 401 | // Get our callee. |
| 402 | llvm::Type *Ty = |
| 403 | CGM.getTypes().GetFunctionType(CGM.getTypes().arrangeGlobalDeclaration(GD)); |
| 404 | llvm::Value *Callee = CGM.GetAddrOfFunction(GD, Ty, /*ForVTable=*/true); |
| 405 | |
| 406 | // Make the call and return the result. |
Stephen Hines | 176edba | 2014-12-01 14:53:08 -0800 | [diff] [blame] | 407 | EmitCallAndReturnForThunk(Callee, &Thunk); |
Anders Carlsson | 519c328 | 2010-03-24 00:39:18 +0000 | [diff] [blame] | 408 | } |
| 409 | |
Timur Iskhodzhanov | 2cb17a0 | 2013-10-09 09:23:58 +0000 | [diff] [blame] | 410 | void CodeGenVTables::emitThunk(GlobalDecl GD, const ThunkInfo &Thunk, |
| 411 | bool ForVTable) { |
John McCall | de5d3c7 | 2012-02-17 03:33:10 +0000 | [diff] [blame] | 412 | const CGFunctionInfo &FnInfo = CGM.getTypes().arrangeGlobalDeclaration(GD); |
John McCall | d26bc76 | 2011-03-09 04:27:21 +0000 | [diff] [blame] | 413 | |
| 414 | // FIXME: re-use FnInfo in this computation. |
Stephen Hines | 6bcf27b | 2014-05-29 04:14:42 -0700 | [diff] [blame] | 415 | llvm::Constant *C = CGM.GetAddrOfThunk(GD, Thunk); |
| 416 | llvm::GlobalValue *Entry; |
| 417 | |
Anders Carlsson | 7986ad5 | 2010-03-23 18:18:41 +0000 | [diff] [blame] | 418 | // Strip off a bitcast if we got one back. |
Stephen Hines | 6bcf27b | 2014-05-29 04:14:42 -0700 | [diff] [blame] | 419 | if (llvm::ConstantExpr *CE = dyn_cast<llvm::ConstantExpr>(C)) { |
Anders Carlsson | 7986ad5 | 2010-03-23 18:18:41 +0000 | [diff] [blame] | 420 | assert(CE->getOpcode() == llvm::Instruction::BitCast); |
Stephen Hines | 6bcf27b | 2014-05-29 04:14:42 -0700 | [diff] [blame] | 421 | Entry = cast<llvm::GlobalValue>(CE->getOperand(0)); |
| 422 | } else { |
| 423 | Entry = cast<llvm::GlobalValue>(C); |
Anders Carlsson | 7986ad5 | 2010-03-23 18:18:41 +0000 | [diff] [blame] | 424 | } |
Stephen Hines | 6bcf27b | 2014-05-29 04:14:42 -0700 | [diff] [blame] | 425 | |
Anders Carlsson | 7986ad5 | 2010-03-23 18:18:41 +0000 | [diff] [blame] | 426 | // There's already a declaration with the same name, check if it has the same |
| 427 | // type or if we need to replace it. |
Stephen Hines | 6bcf27b | 2014-05-29 04:14:42 -0700 | [diff] [blame] | 428 | if (Entry->getType()->getElementType() != |
John McCall | 4c40d98 | 2010-08-31 07:33:07 +0000 | [diff] [blame] | 429 | CGM.getTypes().GetFunctionTypeForVTable(GD)) { |
Stephen Hines | 6bcf27b | 2014-05-29 04:14:42 -0700 | [diff] [blame] | 430 | llvm::GlobalValue *OldThunkFn = Entry; |
| 431 | |
Anders Carlsson | 7986ad5 | 2010-03-23 18:18:41 +0000 | [diff] [blame] | 432 | // If the types mismatch then we have to rewrite the definition. |
| 433 | assert(OldThunkFn->isDeclaration() && |
| 434 | "Shouldn't replace non-declaration"); |
| 435 | |
| 436 | // Remove the name from the old thunk function and get a new thunk. |
Chris Lattner | 5f9e272 | 2011-07-23 10:55:15 +0000 | [diff] [blame] | 437 | OldThunkFn->setName(StringRef()); |
Stephen Hines | 6bcf27b | 2014-05-29 04:14:42 -0700 | [diff] [blame] | 438 | Entry = cast<llvm::GlobalValue>(CGM.GetAddrOfThunk(GD, Thunk)); |
Anders Carlsson | 7986ad5 | 2010-03-23 18:18:41 +0000 | [diff] [blame] | 439 | |
| 440 | // If needed, replace the old thunk with a bitcast. |
| 441 | if (!OldThunkFn->use_empty()) { |
| 442 | llvm::Constant *NewPtrForOldDecl = |
Anders Carlsson | 13d6898 | 2010-03-24 00:35:44 +0000 | [diff] [blame] | 443 | llvm::ConstantExpr::getBitCast(Entry, OldThunkFn->getType()); |
Anders Carlsson | 7986ad5 | 2010-03-23 18:18:41 +0000 | [diff] [blame] | 444 | OldThunkFn->replaceAllUsesWith(NewPtrForOldDecl); |
| 445 | } |
| 446 | |
| 447 | // Remove the old thunk. |
| 448 | OldThunkFn->eraseFromParent(); |
| 449 | } |
Anders Carlsson | 519c328 | 2010-03-24 00:39:18 +0000 | [diff] [blame] | 450 | |
Anders Carlsson | 519c328 | 2010-03-24 00:39:18 +0000 | [diff] [blame] | 451 | llvm::Function *ThunkFn = cast<llvm::Function>(Entry); |
Timur Iskhodzhanov | 2cb17a0 | 2013-10-09 09:23:58 +0000 | [diff] [blame] | 452 | bool ABIHasKeyFunctions = CGM.getTarget().getCXXABI().hasKeyFunctions(); |
| 453 | bool UseAvailableExternallyLinkage = ForVTable && ABIHasKeyFunctions; |
Anders Carlsson | 14e82fd | 2011-02-06 18:31:40 +0000 | [diff] [blame] | 454 | |
| 455 | if (!ThunkFn->isDeclaration()) { |
Timur Iskhodzhanov | 2cb17a0 | 2013-10-09 09:23:58 +0000 | [diff] [blame] | 456 | if (!ABIHasKeyFunctions || UseAvailableExternallyLinkage) { |
Anders Carlsson | 14e82fd | 2011-02-06 18:31:40 +0000 | [diff] [blame] | 457 | // There is already a thunk emitted for this function, do nothing. |
| 458 | return; |
| 459 | } |
| 460 | |
Pirama Arumuga Nainar | 87d948e | 2016-03-03 15:49:35 -0800 | [diff] [blame] | 461 | setThunkProperties(CGM, Thunk, ThunkFn, ForVTable, GD); |
Anders Carlsson | 22df7b1 | 2011-02-06 20:09:44 +0000 | [diff] [blame] | 462 | return; |
Anders Carlsson | 14e82fd | 2011-02-06 18:31:40 +0000 | [diff] [blame] | 463 | } |
| 464 | |
Rafael Espindola | 022301b | 2012-09-21 20:39:32 +0000 | [diff] [blame] | 465 | CGM.SetLLVMFunctionAttributesForDefinition(GD.getDecl(), ThunkFn); |
| 466 | |
Eli Friedman | 7dcdf5b | 2011-05-06 17:27:27 +0000 | [diff] [blame] | 467 | if (ThunkFn->isVarArg()) { |
| 468 | // Varargs thunks are special; we can't just generate a call because |
| 469 | // we can't copy the varargs. Our implementation is rather |
| 470 | // expensive/sucky at the moment, so don't generate the thunk unless |
| 471 | // we have to. |
| 472 | // FIXME: Do something better here; GenerateVarArgsThunk is extremely ugly. |
Pirama Arumuga Nainar | 87d948e | 2016-03-03 15:49:35 -0800 | [diff] [blame] | 473 | if (UseAvailableExternallyLinkage) |
| 474 | return; |
| 475 | ThunkFn = |
| 476 | CodeGenFunction(CGM).GenerateVarArgsThunk(ThunkFn, FnInfo, GD, Thunk); |
Eli Friedman | 7dcdf5b | 2011-05-06 17:27:27 +0000 | [diff] [blame] | 477 | } else { |
| 478 | // Normal thunk body generation. |
Pirama Arumuga Nainar | 87d948e | 2016-03-03 15:49:35 -0800 | [diff] [blame] | 479 | CodeGenFunction(CGM).generateThunk(ThunkFn, FnInfo, GD, Thunk); |
Eli Friedman | 7dcdf5b | 2011-05-06 17:27:27 +0000 | [diff] [blame] | 480 | } |
Pirama Arumuga Nainar | 87d948e | 2016-03-03 15:49:35 -0800 | [diff] [blame] | 481 | |
| 482 | setThunkProperties(CGM, Thunk, ThunkFn, ForVTable, GD); |
Anders Carlsson | 14e82fd | 2011-02-06 18:31:40 +0000 | [diff] [blame] | 483 | } |
| 484 | |
Timur Iskhodzhanov | 2cb17a0 | 2013-10-09 09:23:58 +0000 | [diff] [blame] | 485 | void CodeGenVTables::maybeEmitThunkForVTable(GlobalDecl GD, |
| 486 | const ThunkInfo &Thunk) { |
| 487 | // If the ABI has key functions, only the TU with the key function should emit |
| 488 | // the thunk. However, we can allow inlining of thunks if we emit them with |
| 489 | // available_externally linkage together with vtables when optimizations are |
| 490 | // enabled. |
| 491 | if (CGM.getTarget().getCXXABI().hasKeyFunctions() && |
| 492 | !CGM.getCodeGenOpts().OptimizationLevel) |
Anders Carlsson | 14e82fd | 2011-02-06 18:31:40 +0000 | [diff] [blame] | 493 | return; |
| 494 | |
| 495 | // We can't emit thunks for member functions with incomplete types. |
| 496 | const CXXMethodDecl *MD = cast<CXXMethodDecl>(GD.getDecl()); |
Chris Lattner | f742eb0 | 2011-07-10 00:18:59 +0000 | [diff] [blame] | 497 | if (!CGM.getTypes().isFuncTypeConvertible( |
Reid Kleckner | 7bb7230 | 2013-10-11 20:46:27 +0000 | [diff] [blame] | 498 | MD->getType()->castAs<FunctionType>())) |
Anders Carlsson | 14e82fd | 2011-02-06 18:31:40 +0000 | [diff] [blame] | 499 | return; |
| 500 | |
Timur Iskhodzhanov | 2cb17a0 | 2013-10-09 09:23:58 +0000 | [diff] [blame] | 501 | emitThunk(GD, Thunk, /*ForVTable=*/true); |
Anders Carlsson | fbf6ed4 | 2010-03-23 16:36:50 +0000 | [diff] [blame] | 502 | } |
| 503 | |
Anders Carlsson | ee5ab9f | 2010-03-23 04:59:02 +0000 | [diff] [blame] | 504 | void CodeGenVTables::EmitThunks(GlobalDecl GD) |
| 505 | { |
Anders Carlsson | fbf6ed4 | 2010-03-23 16:36:50 +0000 | [diff] [blame] | 506 | const CXXMethodDecl *MD = |
| 507 | cast<CXXMethodDecl>(GD.getDecl())->getCanonicalDecl(); |
| 508 | |
| 509 | // We don't need to generate thunks for the base destructor. |
| 510 | if (isa<CXXDestructorDecl>(MD) && GD.getDtorType() == Dtor_Base) |
| 511 | return; |
| 512 | |
Stephen Hines | 651f13c | 2014-04-23 16:59:28 -0700 | [diff] [blame] | 513 | const VTableContextBase::ThunkInfoVectorTy *ThunkInfoVector = |
| 514 | VTContext->getThunkInfo(GD); |
Timur Iskhodzhanov | 635de28 | 2013-07-30 09:46:19 +0000 | [diff] [blame] | 515 | |
Peter Collingbourne | 84fcc48 | 2011-09-26 01:56:41 +0000 | [diff] [blame] | 516 | if (!ThunkInfoVector) |
Anders Carlsson | ccd83d7 | 2010-03-24 16:42:11 +0000 | [diff] [blame] | 517 | return; |
Anders Carlsson | ccd83d7 | 2010-03-24 16:42:11 +0000 | [diff] [blame] | 518 | |
Pirama Arumuga Nainar | 87d948e | 2016-03-03 15:49:35 -0800 | [diff] [blame] | 519 | for (const ThunkInfo& Thunk : *ThunkInfoVector) |
| 520 | emitThunk(GD, Thunk, /*ForVTable=*/false); |
Anders Carlsson | ee5ab9f | 2010-03-23 04:59:02 +0000 | [diff] [blame] | 521 | } |
| 522 | |
Stephen Hines | c568f1e | 2014-07-21 00:47:37 -0700 | [diff] [blame] | 523 | llvm::Constant *CodeGenVTables::CreateVTableInitializer( |
| 524 | const CXXRecordDecl *RD, const VTableComponent *Components, |
| 525 | unsigned NumComponents, const VTableLayout::VTableThunkTy *VTableThunks, |
| 526 | unsigned NumVTableThunks, llvm::Constant *RTTI) { |
Chris Lattner | 5f9e272 | 2011-07-23 10:55:15 +0000 | [diff] [blame] | 527 | SmallVector<llvm::Constant *, 64> Inits; |
Anders Carlsson | 0d1407e | 2010-03-25 15:26:28 +0000 | [diff] [blame] | 528 | |
Chris Lattner | 8b41868 | 2012-02-07 00:39:47 +0000 | [diff] [blame] | 529 | llvm::Type *Int8PtrTy = CGM.Int8PtrTy; |
Anders Carlsson | 0d1407e | 2010-03-25 15:26:28 +0000 | [diff] [blame] | 530 | |
Chris Lattner | 2acc6e3 | 2011-07-18 04:24:23 +0000 | [diff] [blame] | 531 | llvm::Type *PtrDiffTy = |
Anders Carlsson | 6a5ab5d | 2010-03-25 16:49:53 +0000 | [diff] [blame] | 532 | CGM.getTypes().ConvertType(CGM.getContext().getPointerDiffType()); |
| 533 | |
Anders Carlsson | 6a5ab5d | 2010-03-25 16:49:53 +0000 | [diff] [blame] | 534 | unsigned NextVTableThunkIndex = 0; |
Stephen Hines | 6bcf27b | 2014-05-29 04:14:42 -0700 | [diff] [blame] | 535 | |
| 536 | llvm::Constant *PureVirtualFn = nullptr, *DeletedVirtualFn = nullptr; |
Anders Carlsson | 67d568a | 2010-03-29 05:40:50 +0000 | [diff] [blame] | 537 | |
Anders Carlsson | 0d1407e | 2010-03-25 15:26:28 +0000 | [diff] [blame] | 538 | for (unsigned I = 0; I != NumComponents; ++I) { |
Peter Collingbourne | e09cdf4 | 2011-09-26 01:56:50 +0000 | [diff] [blame] | 539 | VTableComponent Component = Components[I]; |
Anders Carlsson | 6a5ab5d | 2010-03-25 16:49:53 +0000 | [diff] [blame] | 540 | |
Stephen Hines | 6bcf27b | 2014-05-29 04:14:42 -0700 | [diff] [blame] | 541 | llvm::Constant *Init = nullptr; |
Anders Carlsson | 6a5ab5d | 2010-03-25 16:49:53 +0000 | [diff] [blame] | 542 | |
| 543 | switch (Component.getKind()) { |
Anders Carlsson | 9446481 | 2010-04-10 19:13:06 +0000 | [diff] [blame] | 544 | case VTableComponent::CK_VCallOffset: |
Ken Dyck | c40a3fd | 2011-04-02 01:14:48 +0000 | [diff] [blame] | 545 | Init = llvm::ConstantInt::get(PtrDiffTy, |
| 546 | Component.getVCallOffset().getQuantity()); |
Anders Carlsson | 6a5ab5d | 2010-03-25 16:49:53 +0000 | [diff] [blame] | 547 | Init = llvm::ConstantExpr::getIntToPtr(Init, Int8PtrTy); |
| 548 | break; |
Anders Carlsson | 9446481 | 2010-04-10 19:13:06 +0000 | [diff] [blame] | 549 | case VTableComponent::CK_VBaseOffset: |
Ken Dyck | c40a3fd | 2011-04-02 01:14:48 +0000 | [diff] [blame] | 550 | Init = llvm::ConstantInt::get(PtrDiffTy, |
| 551 | Component.getVBaseOffset().getQuantity()); |
Anders Carlsson | 6a5ab5d | 2010-03-25 16:49:53 +0000 | [diff] [blame] | 552 | Init = llvm::ConstantExpr::getIntToPtr(Init, Int8PtrTy); |
| 553 | break; |
Anders Carlsson | 9446481 | 2010-04-10 19:13:06 +0000 | [diff] [blame] | 554 | case VTableComponent::CK_OffsetToTop: |
Ken Dyck | c40a3fd | 2011-04-02 01:14:48 +0000 | [diff] [blame] | 555 | Init = llvm::ConstantInt::get(PtrDiffTy, |
| 556 | Component.getOffsetToTop().getQuantity()); |
Anders Carlsson | 6a5ab5d | 2010-03-25 16:49:53 +0000 | [diff] [blame] | 557 | Init = llvm::ConstantExpr::getIntToPtr(Init, Int8PtrTy); |
| 558 | break; |
Anders Carlsson | 9446481 | 2010-04-10 19:13:06 +0000 | [diff] [blame] | 559 | case VTableComponent::CK_RTTI: |
Anders Carlsson | 6a5ab5d | 2010-03-25 16:49:53 +0000 | [diff] [blame] | 560 | Init = llvm::ConstantExpr::getBitCast(RTTI, Int8PtrTy); |
| 561 | break; |
Anders Carlsson | 9446481 | 2010-04-10 19:13:06 +0000 | [diff] [blame] | 562 | case VTableComponent::CK_FunctionPointer: |
| 563 | case VTableComponent::CK_CompleteDtorPointer: |
| 564 | case VTableComponent::CK_DeletingDtorPointer: { |
Anders Carlsson | 6a5ab5d | 2010-03-25 16:49:53 +0000 | [diff] [blame] | 565 | GlobalDecl GD; |
| 566 | |
| 567 | // Get the right global decl. |
| 568 | switch (Component.getKind()) { |
| 569 | default: |
| 570 | llvm_unreachable("Unexpected vtable component kind"); |
Anders Carlsson | 9446481 | 2010-04-10 19:13:06 +0000 | [diff] [blame] | 571 | case VTableComponent::CK_FunctionPointer: |
Anders Carlsson | 6a5ab5d | 2010-03-25 16:49:53 +0000 | [diff] [blame] | 572 | GD = Component.getFunctionDecl(); |
| 573 | break; |
Anders Carlsson | 9446481 | 2010-04-10 19:13:06 +0000 | [diff] [blame] | 574 | case VTableComponent::CK_CompleteDtorPointer: |
Anders Carlsson | 6a5ab5d | 2010-03-25 16:49:53 +0000 | [diff] [blame] | 575 | GD = GlobalDecl(Component.getDestructorDecl(), Dtor_Complete); |
| 576 | break; |
Anders Carlsson | 9446481 | 2010-04-10 19:13:06 +0000 | [diff] [blame] | 577 | case VTableComponent::CK_DeletingDtorPointer: |
Anders Carlsson | 6a5ab5d | 2010-03-25 16:49:53 +0000 | [diff] [blame] | 578 | GD = GlobalDecl(Component.getDestructorDecl(), Dtor_Deleting); |
| 579 | break; |
| 580 | } |
| 581 | |
Pirama Arumuga Nainar | 87d948e | 2016-03-03 15:49:35 -0800 | [diff] [blame] | 582 | if (CGM.getLangOpts().CUDA) { |
| 583 | // Emit NULL for methods we can't codegen on this |
| 584 | // side. Otherwise we'd end up with vtable with unresolved |
| 585 | // references. |
| 586 | const CXXMethodDecl *MD = cast<CXXMethodDecl>(GD.getDecl()); |
| 587 | // OK on device side: functions w/ __device__ attribute |
| 588 | // OK on host side: anything except __device__-only functions. |
| 589 | bool CanEmitMethod = CGM.getLangOpts().CUDAIsDevice |
| 590 | ? MD->hasAttr<CUDADeviceAttr>() |
| 591 | : (MD->hasAttr<CUDAHostAttr>() || |
| 592 | !MD->hasAttr<CUDADeviceAttr>()); |
| 593 | if (!CanEmitMethod) { |
| 594 | Init = llvm::ConstantExpr::getNullValue(Int8PtrTy); |
| 595 | break; |
| 596 | } |
| 597 | // Method is acceptable, continue processing as usual. |
| 598 | } |
| 599 | |
Anders Carlsson | 67d568a | 2010-03-29 05:40:50 +0000 | [diff] [blame] | 600 | if (cast<CXXMethodDecl>(GD.getDecl())->isPure()) { |
| 601 | // We have a pure virtual member function. |
Joao Matos | e9af3e6 | 2012-07-17 19:17:58 +0000 | [diff] [blame] | 602 | if (!PureVirtualFn) { |
Eli Friedman | cf15f17 | 2012-09-14 01:19:01 +0000 | [diff] [blame] | 603 | llvm::FunctionType *Ty = |
| 604 | llvm::FunctionType::get(CGM.VoidTy, /*isVarArg=*/false); |
| 605 | StringRef PureCallName = CGM.getCXXABI().GetPureVirtualCallName(); |
| 606 | PureVirtualFn = CGM.CreateRuntimeFunction(Ty, PureCallName); |
Pirama Arumuga Nainar | 4967a71 | 2016-09-19 22:19:55 -0700 | [diff] [blame^] | 607 | if (auto *F = dyn_cast<llvm::Function>(PureVirtualFn)) |
| 608 | F->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global); |
Eli Friedman | cf15f17 | 2012-09-14 01:19:01 +0000 | [diff] [blame] | 609 | PureVirtualFn = llvm::ConstantExpr::getBitCast(PureVirtualFn, |
Joao Matos | e9af3e6 | 2012-07-17 19:17:58 +0000 | [diff] [blame] | 610 | CGM.Int8PtrTy); |
Anders Carlsson | 67d568a | 2010-03-29 05:40:50 +0000 | [diff] [blame] | 611 | } |
Anders Carlsson | 67d568a | 2010-03-29 05:40:50 +0000 | [diff] [blame] | 612 | Init = PureVirtualFn; |
David Blaikie | 2eb9a95 | 2012-10-16 22:56:05 +0000 | [diff] [blame] | 613 | } else if (cast<CXXMethodDecl>(GD.getDecl())->isDeleted()) { |
| 614 | if (!DeletedVirtualFn) { |
| 615 | llvm::FunctionType *Ty = |
| 616 | llvm::FunctionType::get(CGM.VoidTy, /*isVarArg=*/false); |
| 617 | StringRef DeletedCallName = |
| 618 | CGM.getCXXABI().GetDeletedVirtualCallName(); |
| 619 | DeletedVirtualFn = CGM.CreateRuntimeFunction(Ty, DeletedCallName); |
Pirama Arumuga Nainar | 4967a71 | 2016-09-19 22:19:55 -0700 | [diff] [blame^] | 620 | if (auto *F = dyn_cast<llvm::Function>(DeletedVirtualFn)) |
| 621 | F->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global); |
David Blaikie | 2eb9a95 | 2012-10-16 22:56:05 +0000 | [diff] [blame] | 622 | DeletedVirtualFn = llvm::ConstantExpr::getBitCast(DeletedVirtualFn, |
| 623 | CGM.Int8PtrTy); |
| 624 | } |
| 625 | Init = DeletedVirtualFn; |
Anders Carlsson | 6a5ab5d | 2010-03-25 16:49:53 +0000 | [diff] [blame] | 626 | } else { |
Anders Carlsson | 67d568a | 2010-03-29 05:40:50 +0000 | [diff] [blame] | 627 | // Check if we should use a thunk. |
Peter Collingbourne | e09cdf4 | 2011-09-26 01:56:50 +0000 | [diff] [blame] | 628 | if (NextVTableThunkIndex < NumVTableThunks && |
Anders Carlsson | 67d568a | 2010-03-29 05:40:50 +0000 | [diff] [blame] | 629 | VTableThunks[NextVTableThunkIndex].first == I) { |
| 630 | const ThunkInfo &Thunk = VTableThunks[NextVTableThunkIndex].second; |
Anders Carlsson | 6a5ab5d | 2010-03-25 16:49:53 +0000 | [diff] [blame] | 631 | |
Timur Iskhodzhanov | 2cb17a0 | 2013-10-09 09:23:58 +0000 | [diff] [blame] | 632 | maybeEmitThunkForVTable(GD, Thunk); |
Benjamin Kramer | fce8009 | 2012-03-20 20:18:13 +0000 | [diff] [blame] | 633 | Init = CGM.GetAddrOfThunk(GD, Thunk); |
Anders Carlsson | 14e82fd | 2011-02-06 18:31:40 +0000 | [diff] [blame] | 634 | |
Anders Carlsson | 67d568a | 2010-03-29 05:40:50 +0000 | [diff] [blame] | 635 | NextVTableThunkIndex++; |
| 636 | } else { |
Chris Lattner | 2acc6e3 | 2011-07-18 04:24:23 +0000 | [diff] [blame] | 637 | llvm::Type *Ty = CGM.getTypes().GetFunctionTypeForVTable(GD); |
Anders Carlsson | 67d568a | 2010-03-29 05:40:50 +0000 | [diff] [blame] | 638 | |
Anders Carlsson | 1faa89f | 2011-02-05 04:35:53 +0000 | [diff] [blame] | 639 | Init = CGM.GetAddrOfFunction(GD, Ty, /*ForVTable=*/true); |
Anders Carlsson | 67d568a | 2010-03-29 05:40:50 +0000 | [diff] [blame] | 640 | } |
| 641 | |
| 642 | Init = llvm::ConstantExpr::getBitCast(Init, Int8PtrTy); |
Anders Carlsson | 6a5ab5d | 2010-03-25 16:49:53 +0000 | [diff] [blame] | 643 | } |
Anders Carlsson | 6a5ab5d | 2010-03-25 16:49:53 +0000 | [diff] [blame] | 644 | break; |
| 645 | } |
| 646 | |
Anders Carlsson | 9446481 | 2010-04-10 19:13:06 +0000 | [diff] [blame] | 647 | case VTableComponent::CK_UnusedFunctionPointer: |
Anders Carlsson | 6a5ab5d | 2010-03-25 16:49:53 +0000 | [diff] [blame] | 648 | Init = llvm::ConstantExpr::getNullValue(Int8PtrTy); |
| 649 | break; |
| 650 | }; |
Anders Carlsson | 0d1407e | 2010-03-25 15:26:28 +0000 | [diff] [blame] | 651 | |
| 652 | Inits.push_back(Init); |
| 653 | } |
| 654 | |
| 655 | llvm::ArrayType *ArrayType = llvm::ArrayType::get(Int8PtrTy, NumComponents); |
Jay Foad | 9735760 | 2011-06-22 09:24:39 +0000 | [diff] [blame] | 656 | return llvm::ConstantArray::get(ArrayType, Inits); |
Anders Carlsson | 0d1407e | 2010-03-25 15:26:28 +0000 | [diff] [blame] | 657 | } |
| 658 | |
Anders Carlsson | ff143f8 | 2010-03-25 00:35:49 +0000 | [diff] [blame] | 659 | llvm::GlobalVariable * |
| 660 | CodeGenVTables::GenerateConstructionVTable(const CXXRecordDecl *RD, |
Anders Carlsson | 2c822f1 | 2010-03-26 03:56:54 +0000 | [diff] [blame] | 661 | const BaseSubobject &Base, |
| 662 | bool BaseIsVirtual, |
John McCall | bda0d6b | 2011-03-27 09:00:25 +0000 | [diff] [blame] | 663 | llvm::GlobalVariable::LinkageTypes Linkage, |
Anders Carlsson | 2c822f1 | 2010-03-26 03:56:54 +0000 | [diff] [blame] | 664 | VTableAddressPointsMapTy& AddressPoints) { |
David Blaikie | 6a29f67 | 2013-08-22 15:23:05 +0000 | [diff] [blame] | 665 | if (CGDebugInfo *DI = CGM.getModuleDebugInfo()) |
| 666 | DI->completeClassData(Base.getBase()); |
| 667 | |
Stephen Hines | 651f13c | 2014-04-23 16:59:28 -0700 | [diff] [blame] | 668 | std::unique_ptr<VTableLayout> VTLayout( |
| 669 | getItaniumVTableContext().createConstructionVTableLayout( |
Timur Iskhodzhanov | 5f0db58 | 2013-11-05 15:54:58 +0000 | [diff] [blame] | 670 | Base.getBase(), Base.getBaseOffset(), BaseIsVirtual, RD)); |
Anders Carlsson | 0d1407e | 2010-03-25 15:26:28 +0000 | [diff] [blame] | 671 | |
Anders Carlsson | 6a5ab5d | 2010-03-25 16:49:53 +0000 | [diff] [blame] | 672 | // Add the address points. |
Peter Collingbourne | ab172b5 | 2011-09-26 01:57:04 +0000 | [diff] [blame] | 673 | AddressPoints = VTLayout->getAddressPoints(); |
Anders Carlsson | 0d1407e | 2010-03-25 15:26:28 +0000 | [diff] [blame] | 674 | |
| 675 | // Get the mangled construction vtable name. |
Dylan Noblesmith | f7ccbad | 2012-02-05 02:13:05 +0000 | [diff] [blame] | 676 | SmallString<256> OutName; |
Rafael Espindola | f0be979 | 2011-02-11 02:52:17 +0000 | [diff] [blame] | 677 | llvm::raw_svector_ostream Out(OutName); |
Timur Iskhodzhanov | 11f22a3 | 2013-10-03 06:26:13 +0000 | [diff] [blame] | 678 | cast<ItaniumMangleContext>(CGM.getCXXABI().getMangleContext()) |
| 679 | .mangleCXXCtorVTable(RD, Base.getBaseOffset().getQuantity(), |
| 680 | Base.getBase(), Out); |
Chris Lattner | 5f9e272 | 2011-07-23 10:55:15 +0000 | [diff] [blame] | 681 | StringRef Name = OutName.str(); |
Anders Carlsson | 0d1407e | 2010-03-25 15:26:28 +0000 | [diff] [blame] | 682 | |
Anders Carlsson | 0d1407e | 2010-03-25 15:26:28 +0000 | [diff] [blame] | 683 | llvm::ArrayType *ArrayType = |
Chris Lattner | 8b41868 | 2012-02-07 00:39:47 +0000 | [diff] [blame] | 684 | llvm::ArrayType::get(CGM.Int8PtrTy, VTLayout->getNumVTableComponents()); |
Anders Carlsson | 0d1407e | 2010-03-25 15:26:28 +0000 | [diff] [blame] | 685 | |
Richard Smith | b4127a2 | 2013-02-16 00:51:21 +0000 | [diff] [blame] | 686 | // Construction vtable symbols are not part of the Itanium ABI, so we cannot |
| 687 | // guarantee that they actually will be available externally. Instead, when |
| 688 | // emitting an available_externally VTT, we provide references to an internal |
| 689 | // linkage construction vtable. The ABI only requires complete-object vtables |
| 690 | // to be the same for all instances of a type, not construction vtables. |
| 691 | if (Linkage == llvm::GlobalVariable::AvailableExternallyLinkage) |
| 692 | Linkage = llvm::GlobalVariable::InternalLinkage; |
| 693 | |
Anders Carlsson | 0d1407e | 2010-03-25 15:26:28 +0000 | [diff] [blame] | 694 | // Create the variable that will hold the construction vtable. |
| 695 | llvm::GlobalVariable *VTable = |
John McCall | bda0d6b | 2011-03-27 09:00:25 +0000 | [diff] [blame] | 696 | CGM.CreateOrReplaceCXXRuntimeVariable(Name, ArrayType, Linkage); |
Stephen Hines | 651f13c | 2014-04-23 16:59:28 -0700 | [diff] [blame] | 697 | CGM.setGlobalVisibility(VTable, RD); |
John McCall | bda0d6b | 2011-03-27 09:00:25 +0000 | [diff] [blame] | 698 | |
| 699 | // V-tables are always unnamed_addr. |
Pirama Arumuga Nainar | 4967a71 | 2016-09-19 22:19:55 -0700 | [diff] [blame^] | 700 | VTable->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global); |
Anders Carlsson | 0d1407e | 2010-03-25 15:26:28 +0000 | [diff] [blame] | 701 | |
Stephen Hines | c568f1e | 2014-07-21 00:47:37 -0700 | [diff] [blame] | 702 | llvm::Constant *RTTI = CGM.GetAddrOfRTTIDescriptor( |
| 703 | CGM.getContext().getTagDeclType(Base.getBase())); |
| 704 | |
Anders Carlsson | 0d1407e | 2010-03-25 15:26:28 +0000 | [diff] [blame] | 705 | // Create and set the initializer. |
Stephen Hines | c568f1e | 2014-07-21 00:47:37 -0700 | [diff] [blame] | 706 | llvm::Constant *Init = CreateVTableInitializer( |
| 707 | Base.getBase(), VTLayout->vtable_component_begin(), |
| 708 | VTLayout->getNumVTableComponents(), VTLayout->vtable_thunk_begin(), |
| 709 | VTLayout->getNumVTableThunks(), RTTI); |
Anders Carlsson | 0d1407e | 2010-03-25 15:26:28 +0000 | [diff] [blame] | 710 | VTable->setInitializer(Init); |
| 711 | |
Pirama Arumuga Nainar | 4967a71 | 2016-09-19 22:19:55 -0700 | [diff] [blame^] | 712 | CGM.EmitVTableTypeMetadata(VTable, *VTLayout.get()); |
Stephen Hines | 0e2c34f | 2015-03-23 12:09:02 -0700 | [diff] [blame] | 713 | |
Anders Carlsson | ff143f8 | 2010-03-25 00:35:49 +0000 | [diff] [blame] | 714 | return VTable; |
| 715 | } |
| 716 | |
Pirama Arumuga Nainar | 87d948e | 2016-03-03 15:49:35 -0800 | [diff] [blame] | 717 | static bool shouldEmitAvailableExternallyVTable(const CodeGenModule &CGM, |
| 718 | const CXXRecordDecl *RD) { |
| 719 | return CGM.getCodeGenOpts().OptimizationLevel > 0 && |
| 720 | CGM.getCXXABI().canSpeculativelyEmitVTable(RD); |
| 721 | } |
| 722 | |
Pirama Arumuga Nainar | 4967a71 | 2016-09-19 22:19:55 -0700 | [diff] [blame^] | 723 | /// Compute the required linkage of the vtable for the given class. |
John McCall | d5617ee | 2013-01-25 22:31:03 +0000 | [diff] [blame] | 724 | /// |
| 725 | /// Note that we only call this at the end of the translation unit. |
| 726 | llvm::GlobalVariable::LinkageTypes |
| 727 | CodeGenModule::getVTableLinkage(const CXXRecordDecl *RD) { |
Rafael Espindola | 181e3ec | 2013-05-13 00:12:11 +0000 | [diff] [blame] | 728 | if (!RD->isExternallyVisible()) |
John McCall | d5617ee | 2013-01-25 22:31:03 +0000 | [diff] [blame] | 729 | return llvm::GlobalVariable::InternalLinkage; |
| 730 | |
| 731 | // We're at the end of the translation unit, so the current key |
| 732 | // function is fully correct. |
Stephen Hines | 176edba | 2014-12-01 14:53:08 -0800 | [diff] [blame] | 733 | const CXXMethodDecl *keyFunction = Context.getCurrentKeyFunction(RD); |
| 734 | if (keyFunction && !RD->hasAttr<DLLImportAttr>()) { |
John McCall | d5617ee | 2013-01-25 22:31:03 +0000 | [diff] [blame] | 735 | // If this class has a key function, use that to determine the |
| 736 | // linkage of the vtable. |
Stephen Hines | 6bcf27b | 2014-05-29 04:14:42 -0700 | [diff] [blame] | 737 | const FunctionDecl *def = nullptr; |
John McCall | d5617ee | 2013-01-25 22:31:03 +0000 | [diff] [blame] | 738 | if (keyFunction->hasBody(def)) |
| 739 | keyFunction = cast<CXXMethodDecl>(def); |
| 740 | |
| 741 | switch (keyFunction->getTemplateSpecializationKind()) { |
| 742 | case TSK_Undeclared: |
| 743 | case TSK_ExplicitSpecialization: |
Pirama Arumuga Nainar | 87d948e | 2016-03-03 15:49:35 -0800 | [diff] [blame] | 744 | assert((def || CodeGenOpts.OptimizationLevel > 0) && |
| 745 | "Shouldn't query vtable linkage without key function or " |
| 746 | "optimizations"); |
| 747 | if (!def && CodeGenOpts.OptimizationLevel > 0) |
| 748 | return llvm::GlobalVariable::AvailableExternallyLinkage; |
| 749 | |
John McCall | d5617ee | 2013-01-25 22:31:03 +0000 | [diff] [blame] | 750 | if (keyFunction->isInlined()) |
| 751 | return !Context.getLangOpts().AppleKext ? |
| 752 | llvm::GlobalVariable::LinkOnceODRLinkage : |
| 753 | llvm::Function::InternalLinkage; |
| 754 | |
| 755 | return llvm::GlobalVariable::ExternalLinkage; |
Pirama Arumuga Nainar | 87d948e | 2016-03-03 15:49:35 -0800 | [diff] [blame] | 756 | |
John McCall | d5617ee | 2013-01-25 22:31:03 +0000 | [diff] [blame] | 757 | case TSK_ImplicitInstantiation: |
| 758 | return !Context.getLangOpts().AppleKext ? |
| 759 | llvm::GlobalVariable::LinkOnceODRLinkage : |
| 760 | llvm::Function::InternalLinkage; |
| 761 | |
| 762 | case TSK_ExplicitInstantiationDefinition: |
| 763 | return !Context.getLangOpts().AppleKext ? |
| 764 | llvm::GlobalVariable::WeakODRLinkage : |
| 765 | llvm::Function::InternalLinkage; |
| 766 | |
| 767 | case TSK_ExplicitInstantiationDeclaration: |
Rafael Espindola | 889a675 | 2013-09-03 21:05:13 +0000 | [diff] [blame] | 768 | llvm_unreachable("Should not have been asked to emit this"); |
John McCall | d5617ee | 2013-01-25 22:31:03 +0000 | [diff] [blame] | 769 | } |
| 770 | } |
| 771 | |
| 772 | // -fapple-kext mode does not support weak linkage, so we must use |
| 773 | // internal linkage. |
| 774 | if (Context.getLangOpts().AppleKext) |
| 775 | return llvm::Function::InternalLinkage; |
Stephen Hines | c568f1e | 2014-07-21 00:47:37 -0700 | [diff] [blame] | 776 | |
| 777 | llvm::GlobalVariable::LinkageTypes DiscardableODRLinkage = |
| 778 | llvm::GlobalValue::LinkOnceODRLinkage; |
| 779 | llvm::GlobalVariable::LinkageTypes NonDiscardableODRLinkage = |
| 780 | llvm::GlobalValue::WeakODRLinkage; |
| 781 | if (RD->hasAttr<DLLExportAttr>()) { |
| 782 | // Cannot discard exported vtables. |
| 783 | DiscardableODRLinkage = NonDiscardableODRLinkage; |
| 784 | } else if (RD->hasAttr<DLLImportAttr>()) { |
| 785 | // Imported vtables are available externally. |
| 786 | DiscardableODRLinkage = llvm::GlobalVariable::AvailableExternallyLinkage; |
| 787 | NonDiscardableODRLinkage = llvm::GlobalVariable::AvailableExternallyLinkage; |
| 788 | } |
| 789 | |
John McCall | d5617ee | 2013-01-25 22:31:03 +0000 | [diff] [blame] | 790 | switch (RD->getTemplateSpecializationKind()) { |
Pirama Arumuga Nainar | 87d948e | 2016-03-03 15:49:35 -0800 | [diff] [blame] | 791 | case TSK_Undeclared: |
| 792 | case TSK_ExplicitSpecialization: |
| 793 | case TSK_ImplicitInstantiation: |
| 794 | return DiscardableODRLinkage; |
John McCall | d5617ee | 2013-01-25 22:31:03 +0000 | [diff] [blame] | 795 | |
Pirama Arumuga Nainar | 87d948e | 2016-03-03 15:49:35 -0800 | [diff] [blame] | 796 | case TSK_ExplicitInstantiationDeclaration: |
Pirama Arumuga Nainar | 4967a71 | 2016-09-19 22:19:55 -0700 | [diff] [blame^] | 797 | // Explicit instantiations in MSVC do not provide vtables, so we must emit |
| 798 | // our own. |
| 799 | if (getTarget().getCXXABI().isMicrosoft()) |
| 800 | return DiscardableODRLinkage; |
Pirama Arumuga Nainar | 87d948e | 2016-03-03 15:49:35 -0800 | [diff] [blame] | 801 | return shouldEmitAvailableExternallyVTable(*this, RD) |
| 802 | ? llvm::GlobalVariable::AvailableExternallyLinkage |
| 803 | : llvm::GlobalVariable::ExternalLinkage; |
John McCall | d5617ee | 2013-01-25 22:31:03 +0000 | [diff] [blame] | 804 | |
Pirama Arumuga Nainar | 87d948e | 2016-03-03 15:49:35 -0800 | [diff] [blame] | 805 | case TSK_ExplicitInstantiationDefinition: |
| 806 | return NonDiscardableODRLinkage; |
John McCall | d5617ee | 2013-01-25 22:31:03 +0000 | [diff] [blame] | 807 | } |
| 808 | |
| 809 | llvm_unreachable("Invalid TemplateSpecializationKind!"); |
| 810 | } |
| 811 | |
Pirama Arumuga Nainar | 4967a71 | 2016-09-19 22:19:55 -0700 | [diff] [blame^] | 812 | /// This is a callback from Sema to tell us that that a particular vtable is |
Stephen Hines | 0e2c34f | 2015-03-23 12:09:02 -0700 | [diff] [blame] | 813 | /// required to be emitted in this translation unit. |
John McCall | d5617ee | 2013-01-25 22:31:03 +0000 | [diff] [blame] | 814 | /// |
Stephen Hines | 0e2c34f | 2015-03-23 12:09:02 -0700 | [diff] [blame] | 815 | /// This is only called for vtables that _must_ be emitted (mainly due to key |
| 816 | /// functions). For weak vtables, CodeGen tracks when they are needed and |
| 817 | /// emits them as-needed. |
| 818 | void CodeGenModule::EmitVTable(CXXRecordDecl *theClass) { |
John McCall | d5617ee | 2013-01-25 22:31:03 +0000 | [diff] [blame] | 819 | VTables.GenerateClassData(theClass); |
| 820 | } |
| 821 | |
Anders Carlsson | a7cde3b | 2010-03-29 03:38:52 +0000 | [diff] [blame] | 822 | void |
John McCall | d5617ee | 2013-01-25 22:31:03 +0000 | [diff] [blame] | 823 | CodeGenVTables::GenerateClassData(const CXXRecordDecl *RD) { |
David Blaikie | 6a29f67 | 2013-08-22 15:23:05 +0000 | [diff] [blame] | 824 | if (CGDebugInfo *DI = CGM.getModuleDebugInfo()) |
| 825 | DI->completeClassData(RD); |
| 826 | |
Reid Kleckner | 9063302 | 2013-06-19 15:20:38 +0000 | [diff] [blame] | 827 | if (RD->getNumVBases()) |
Timur Iskhodzhanov | a53d7a0 | 2013-09-27 14:48:01 +0000 | [diff] [blame] | 828 | CGM.getCXXABI().emitVirtualInheritanceTables(RD); |
Douglas Gregor | 1e201b4 | 2010-04-08 15:52:03 +0000 | [diff] [blame] | 829 | |
Timur Iskhodzhanov | a53d7a0 | 2013-09-27 14:48:01 +0000 | [diff] [blame] | 830 | CGM.getCXXABI().emitVTableDefinitions(*this, RD); |
Anders Carlsson | a7cde3b | 2010-03-29 03:38:52 +0000 | [diff] [blame] | 831 | } |
John McCall | d5617ee | 2013-01-25 22:31:03 +0000 | [diff] [blame] | 832 | |
| 833 | /// At this point in the translation unit, does it appear that can we |
| 834 | /// rely on the vtable being defined elsewhere in the program? |
| 835 | /// |
| 836 | /// The response is really only definitive when called at the end of |
| 837 | /// the translation unit. |
| 838 | /// |
| 839 | /// The only semantic restriction here is that the object file should |
Pirama Arumuga Nainar | 4967a71 | 2016-09-19 22:19:55 -0700 | [diff] [blame^] | 840 | /// not contain a vtable definition when that vtable is defined |
John McCall | d5617ee | 2013-01-25 22:31:03 +0000 | [diff] [blame] | 841 | /// strongly elsewhere. Otherwise, we'd just like to avoid emitting |
Pirama Arumuga Nainar | 4967a71 | 2016-09-19 22:19:55 -0700 | [diff] [blame^] | 842 | /// vtables when unnecessary. |
John McCall | d5617ee | 2013-01-25 22:31:03 +0000 | [diff] [blame] | 843 | bool CodeGenVTables::isVTableExternal(const CXXRecordDecl *RD) { |
Stephen Hines | 651f13c | 2014-04-23 16:59:28 -0700 | [diff] [blame] | 844 | assert(RD->isDynamicClass() && "Non-dynamic classes have no VTable."); |
John McCall | d5617ee | 2013-01-25 22:31:03 +0000 | [diff] [blame] | 845 | |
Pirama Arumuga Nainar | 4967a71 | 2016-09-19 22:19:55 -0700 | [diff] [blame^] | 846 | // We always synthesize vtables if they are needed in the MS ABI. MSVC doesn't |
| 847 | // emit them even if there is an explicit template instantiation. |
| 848 | if (CGM.getTarget().getCXXABI().isMicrosoft()) |
| 849 | return false; |
| 850 | |
John McCall | d5617ee | 2013-01-25 22:31:03 +0000 | [diff] [blame] | 851 | // If we have an explicit instantiation declaration (and not a |
Pirama Arumuga Nainar | 4967a71 | 2016-09-19 22:19:55 -0700 | [diff] [blame^] | 852 | // definition), the vtable is defined elsewhere. |
John McCall | d5617ee | 2013-01-25 22:31:03 +0000 | [diff] [blame] | 853 | TemplateSpecializationKind TSK = RD->getTemplateSpecializationKind(); |
| 854 | if (TSK == TSK_ExplicitInstantiationDeclaration) |
| 855 | return true; |
| 856 | |
| 857 | // Otherwise, if the class is an instantiated template, the |
Pirama Arumuga Nainar | 4967a71 | 2016-09-19 22:19:55 -0700 | [diff] [blame^] | 858 | // vtable must be defined here. |
John McCall | d5617ee | 2013-01-25 22:31:03 +0000 | [diff] [blame] | 859 | if (TSK == TSK_ImplicitInstantiation || |
| 860 | TSK == TSK_ExplicitInstantiationDefinition) |
| 861 | return false; |
| 862 | |
| 863 | // Otherwise, if the class doesn't have a key function (possibly |
Pirama Arumuga Nainar | 4967a71 | 2016-09-19 22:19:55 -0700 | [diff] [blame^] | 864 | // anymore), the vtable must be defined here. |
John McCall | d5617ee | 2013-01-25 22:31:03 +0000 | [diff] [blame] | 865 | const CXXMethodDecl *keyFunction = CGM.getContext().getCurrentKeyFunction(RD); |
| 866 | if (!keyFunction) |
| 867 | return false; |
| 868 | |
| 869 | // Otherwise, if we don't have a definition of the key function, the |
Pirama Arumuga Nainar | 4967a71 | 2016-09-19 22:19:55 -0700 | [diff] [blame^] | 870 | // vtable must be defined somewhere else. |
John McCall | d5617ee | 2013-01-25 22:31:03 +0000 | [diff] [blame] | 871 | return !keyFunction->hasBody(); |
| 872 | } |
| 873 | |
| 874 | /// Given that we're currently at the end of the translation unit, and |
Pirama Arumuga Nainar | 4967a71 | 2016-09-19 22:19:55 -0700 | [diff] [blame^] | 875 | /// we've emitted a reference to the vtable for this class, should |
| 876 | /// we define that vtable? |
John McCall | d5617ee | 2013-01-25 22:31:03 +0000 | [diff] [blame] | 877 | static bool shouldEmitVTableAtEndOfTranslationUnit(CodeGenModule &CGM, |
| 878 | const CXXRecordDecl *RD) { |
Pirama Arumuga Nainar | 87d948e | 2016-03-03 15:49:35 -0800 | [diff] [blame] | 879 | // If vtable is internal then it has to be done. |
| 880 | if (!CGM.getVTables().isVTableExternal(RD)) |
| 881 | return true; |
| 882 | |
| 883 | // If it's external then maybe we will need it as available_externally. |
| 884 | return shouldEmitAvailableExternallyVTable(CGM, RD); |
John McCall | d5617ee | 2013-01-25 22:31:03 +0000 | [diff] [blame] | 885 | } |
| 886 | |
| 887 | /// Given that at some point we emitted a reference to one or more |
Pirama Arumuga Nainar | 4967a71 | 2016-09-19 22:19:55 -0700 | [diff] [blame^] | 888 | /// vtables, and that we are now at the end of the translation unit, |
John McCall | d5617ee | 2013-01-25 22:31:03 +0000 | [diff] [blame] | 889 | /// decide whether we should emit them. |
| 890 | void CodeGenModule::EmitDeferredVTables() { |
| 891 | #ifndef NDEBUG |
| 892 | // Remember the size of DeferredVTables, because we're going to assume |
| 893 | // that this entire operation doesn't modify it. |
| 894 | size_t savedSize = DeferredVTables.size(); |
| 895 | #endif |
| 896 | |
Pirama Arumuga Nainar | 87d948e | 2016-03-03 15:49:35 -0800 | [diff] [blame] | 897 | for (const CXXRecordDecl *RD : DeferredVTables) |
John McCall | d5617ee | 2013-01-25 22:31:03 +0000 | [diff] [blame] | 898 | if (shouldEmitVTableAtEndOfTranslationUnit(*this, RD)) |
| 899 | VTables.GenerateClassData(RD); |
John McCall | d5617ee | 2013-01-25 22:31:03 +0000 | [diff] [blame] | 900 | |
| 901 | assert(savedSize == DeferredVTables.size() && |
Pirama Arumuga Nainar | 4967a71 | 2016-09-19 22:19:55 -0700 | [diff] [blame^] | 902 | "deferred extra vtables during vtable emission?"); |
John McCall | d5617ee | 2013-01-25 22:31:03 +0000 | [diff] [blame] | 903 | DeferredVTables.clear(); |
| 904 | } |
Stephen Hines | 0e2c34f | 2015-03-23 12:09:02 -0700 | [diff] [blame] | 905 | |
Pirama Arumuga Nainar | 4967a71 | 2016-09-19 22:19:55 -0700 | [diff] [blame^] | 906 | bool CodeGenModule::HasHiddenLTOVisibility(const CXXRecordDecl *RD) { |
| 907 | LinkageInfo LV = RD->getLinkageAndVisibility(); |
| 908 | if (!isExternallyVisible(LV.getLinkage())) |
Pirama Arumuga Nainar | 87d948e | 2016-03-03 15:49:35 -0800 | [diff] [blame] | 909 | return true; |
| 910 | |
Pirama Arumuga Nainar | 4967a71 | 2016-09-19 22:19:55 -0700 | [diff] [blame^] | 911 | if (RD->hasAttr<LTOVisibilityPublicAttr>() || RD->hasAttr<UuidAttr>()) |
| 912 | return false; |
| 913 | |
| 914 | if (getTriple().isOSBinFormatCOFF()) { |
| 915 | if (RD->hasAttr<DLLExportAttr>() || RD->hasAttr<DLLImportAttr>()) |
| 916 | return false; |
| 917 | } else { |
| 918 | if (LV.getVisibility() != HiddenVisibility) |
| 919 | return false; |
| 920 | } |
| 921 | |
| 922 | if (getCodeGenOpts().LTOVisibilityPublicStd) { |
| 923 | const DeclContext *DC = RD; |
| 924 | while (1) { |
| 925 | auto *D = cast<Decl>(DC); |
| 926 | DC = DC->getParent(); |
| 927 | if (isa<TranslationUnitDecl>(DC->getRedeclContext())) { |
| 928 | if (auto *ND = dyn_cast<NamespaceDecl>(D)) |
| 929 | if (const IdentifierInfo *II = ND->getIdentifier()) |
| 930 | if (II->isStr("std") || II->isStr("stdext")) |
| 931 | return false; |
| 932 | break; |
| 933 | } |
| 934 | } |
| 935 | } |
| 936 | |
| 937 | return true; |
Pirama Arumuga Nainar | 87d948e | 2016-03-03 15:49:35 -0800 | [diff] [blame] | 938 | } |
| 939 | |
Pirama Arumuga Nainar | 4967a71 | 2016-09-19 22:19:55 -0700 | [diff] [blame^] | 940 | void CodeGenModule::EmitVTableTypeMetadata(llvm::GlobalVariable *VTable, |
| 941 | const VTableLayout &VTLayout) { |
| 942 | if (!getCodeGenOpts().PrepareForLTO) |
Stephen Hines | 0e2c34f | 2015-03-23 12:09:02 -0700 | [diff] [blame] | 943 | return; |
| 944 | |
Pirama Arumuga Nainar | 87d948e | 2016-03-03 15:49:35 -0800 | [diff] [blame] | 945 | CharUnits PointerWidth = |
| 946 | Context.toCharUnitsFromBits(Context.getTargetInfo().getPointerWidth(0)); |
Stephen Hines | 0e2c34f | 2015-03-23 12:09:02 -0700 | [diff] [blame] | 947 | |
Pirama Arumuga Nainar | 87d948e | 2016-03-03 15:49:35 -0800 | [diff] [blame] | 948 | typedef std::pair<const CXXRecordDecl *, unsigned> BSEntry; |
| 949 | std::vector<BSEntry> BitsetEntries; |
Stephen Hines | 0e2c34f | 2015-03-23 12:09:02 -0700 | [diff] [blame] | 950 | // Create a bit set entry for each address point. |
Pirama Arumuga Nainar | 4967a71 | 2016-09-19 22:19:55 -0700 | [diff] [blame^] | 951 | for (auto &&AP : VTLayout.getAddressPoints()) |
Pirama Arumuga Nainar | 87d948e | 2016-03-03 15:49:35 -0800 | [diff] [blame] | 952 | BitsetEntries.push_back(std::make_pair(AP.first.getBase(), AP.second)); |
Stephen Hines | 0e2c34f | 2015-03-23 12:09:02 -0700 | [diff] [blame] | 953 | |
| 954 | // Sort the bit set entries for determinism. |
Pirama Arumuga Nainar | 87d948e | 2016-03-03 15:49:35 -0800 | [diff] [blame] | 955 | std::sort(BitsetEntries.begin(), BitsetEntries.end(), |
| 956 | [this](const BSEntry &E1, const BSEntry &E2) { |
| 957 | if (&E1 == &E2) |
Stephen Hines | 0e2c34f | 2015-03-23 12:09:02 -0700 | [diff] [blame] | 958 | return false; |
| 959 | |
Pirama Arumuga Nainar | 87d948e | 2016-03-03 15:49:35 -0800 | [diff] [blame] | 960 | std::string S1; |
| 961 | llvm::raw_string_ostream O1(S1); |
| 962 | getCXXABI().getMangleContext().mangleTypeName( |
| 963 | QualType(E1.first->getTypeForDecl(), 0), O1); |
| 964 | O1.flush(); |
| 965 | |
| 966 | std::string S2; |
| 967 | llvm::raw_string_ostream O2(S2); |
| 968 | getCXXABI().getMangleContext().mangleTypeName( |
| 969 | QualType(E2.first->getTypeForDecl(), 0), O2); |
| 970 | O2.flush(); |
| 971 | |
Stephen Hines | 0e2c34f | 2015-03-23 12:09:02 -0700 | [diff] [blame] | 972 | if (S1 < S2) |
| 973 | return true; |
| 974 | if (S1 != S2) |
| 975 | return false; |
| 976 | |
Pirama Arumuga Nainar | 87d948e | 2016-03-03 15:49:35 -0800 | [diff] [blame] | 977 | return E1.second < E2.second; |
Stephen Hines | 0e2c34f | 2015-03-23 12:09:02 -0700 | [diff] [blame] | 978 | }); |
| 979 | |
Stephen Hines | 0e2c34f | 2015-03-23 12:09:02 -0700 | [diff] [blame] | 980 | for (auto BitsetEntry : BitsetEntries) |
Pirama Arumuga Nainar | 4967a71 | 2016-09-19 22:19:55 -0700 | [diff] [blame^] | 981 | AddVTableTypeMetadata(VTable, PointerWidth * BitsetEntry.second, |
| 982 | BitsetEntry.first); |
Stephen Hines | 0e2c34f | 2015-03-23 12:09:02 -0700 | [diff] [blame] | 983 | } |