diff options
Diffstat (limited to 'gnu/llvm/tools/clang/lib/CodeGen/CGCXX.cpp')
| -rw-r--r-- | gnu/llvm/tools/clang/lib/CodeGen/CGCXX.cpp | 318 |
1 files changed, 0 insertions, 318 deletions
diff --git a/gnu/llvm/tools/clang/lib/CodeGen/CGCXX.cpp b/gnu/llvm/tools/clang/lib/CodeGen/CGCXX.cpp deleted file mode 100644 index 8b0733fbec3..00000000000 --- a/gnu/llvm/tools/clang/lib/CodeGen/CGCXX.cpp +++ /dev/null @@ -1,318 +0,0 @@ -//===--- CGCXX.cpp - Emit LLVM Code for declarations ----------------------===// -// -// The LLVM Compiler Infrastructure -// -// This file is distributed under the University of Illinois Open Source -// License. See LICENSE.TXT for details. -// -//===----------------------------------------------------------------------===// -// -// This contains code dealing with C++ code generation. -// -//===----------------------------------------------------------------------===// - -// We might split this into multiple files if it gets too unwieldy - -#include "CodeGenModule.h" -#include "CGCXXABI.h" -#include "CodeGenFunction.h" -#include "clang/AST/ASTContext.h" -#include "clang/AST/Decl.h" -#include "clang/AST/DeclCXX.h" -#include "clang/AST/DeclObjC.h" -#include "clang/AST/Mangle.h" -#include "clang/AST/RecordLayout.h" -#include "clang/AST/StmtCXX.h" -#include "clang/Basic/CodeGenOptions.h" -#include "llvm/ADT/StringExtras.h" -using namespace clang; -using namespace CodeGen; - - -/// Try to emit a base destructor as an alias to its primary -/// base-class destructor. -bool CodeGenModule::TryEmitBaseDestructorAsAlias(const CXXDestructorDecl *D) { - if (!getCodeGenOpts().CXXCtorDtorAliases) - return true; - - // Producing an alias to a base class ctor/dtor can degrade debug quality - // as the debugger cannot tell them apart. - if (getCodeGenOpts().OptimizationLevel == 0) - return true; - - // If sanitizing memory to check for use-after-dtor, do not emit as - // an alias, unless this class owns no members. - if (getCodeGenOpts().SanitizeMemoryUseAfterDtor && - !D->getParent()->field_empty()) - return true; - - // If the destructor doesn't have a trivial body, we have to emit it - // separately. - if (!D->hasTrivialBody()) - return true; - - const CXXRecordDecl *Class = D->getParent(); - - // We are going to instrument this destructor, so give up even if it is - // currently empty. - if (Class->mayInsertExtraPadding()) - return true; - - // If we need to manipulate a VTT parameter, give up. - if (Class->getNumVBases()) { - // Extra Credit: passing extra parameters is perfectly safe - // in many calling conventions, so only bail out if the ctor's - // calling convention is nonstandard. - return true; - } - - // If any field has a non-trivial destructor, we have to emit the - // destructor separately. - for (const auto *I : Class->fields()) - if (I->getType().isDestructedType()) - return true; - - // Try to find a unique base class with a non-trivial destructor. - const CXXRecordDecl *UniqueBase = nullptr; - for (const auto &I : Class->bases()) { - - // We're in the base destructor, so skip virtual bases. - if (I.isVirtual()) continue; - - // Skip base classes with trivial destructors. - const auto *Base = - cast<CXXRecordDecl>(I.getType()->getAs<RecordType>()->getDecl()); - if (Base->hasTrivialDestructor()) continue; - - // If we've already found a base class with a non-trivial - // destructor, give up. - if (UniqueBase) return true; - UniqueBase = Base; - } - - // If we didn't find any bases with a non-trivial destructor, then - // the base destructor is actually effectively trivial, which can - // happen if it was needlessly user-defined or if there are virtual - // bases with non-trivial destructors. - if (!UniqueBase) - return true; - - // If the base is at a non-zero offset, give up. - const ASTRecordLayout &ClassLayout = Context.getASTRecordLayout(Class); - if (!ClassLayout.getBaseClassOffset(UniqueBase).isZero()) - return true; - - // Give up if the calling conventions don't match. We could update the call, - // but it is probably not worth it. - const CXXDestructorDecl *BaseD = UniqueBase->getDestructor(); - if (BaseD->getType()->getAs<FunctionType>()->getCallConv() != - D->getType()->getAs<FunctionType>()->getCallConv()) - return true; - - GlobalDecl AliasDecl(D, Dtor_Base); - GlobalDecl TargetDecl(BaseD, Dtor_Base); - - // The alias will use the linkage of the referent. If we can't - // support aliases with that linkage, fail. - llvm::GlobalValue::LinkageTypes Linkage = getFunctionLinkage(AliasDecl); - - // We can't use an alias if the linkage is not valid for one. - if (!llvm::GlobalAlias::isValidLinkage(Linkage)) - return true; - - llvm::GlobalValue::LinkageTypes TargetLinkage = - getFunctionLinkage(TargetDecl); - - // Check if we have it already. - StringRef MangledName = getMangledName(AliasDecl); - llvm::GlobalValue *Entry = GetGlobalValue(MangledName); - if (Entry && !Entry->isDeclaration()) - return false; - if (Replacements.count(MangledName)) - return false; - - // Derive the type for the alias. - llvm::Type *AliasValueType = getTypes().GetFunctionType(AliasDecl); - llvm::PointerType *AliasType = AliasValueType->getPointerTo(); - - // Find the referent. Some aliases might require a bitcast, in - // which case the caller is responsible for ensuring the soundness - // of these semantics. - auto *Ref = cast<llvm::GlobalValue>(GetAddrOfGlobal(TargetDecl)); - llvm::Constant *Aliasee = Ref; - if (Ref->getType() != AliasType) - Aliasee = llvm::ConstantExpr::getBitCast(Ref, AliasType); - - // Instead of creating as alias to a linkonce_odr, replace all of the uses - // of the aliasee. - if (llvm::GlobalValue::isDiscardableIfUnused(Linkage) && - !(TargetLinkage == llvm::GlobalValue::AvailableExternallyLinkage && - TargetDecl.getDecl()->hasAttr<AlwaysInlineAttr>())) { - // FIXME: An extern template instantiation will create functions with - // linkage "AvailableExternally". In libc++, some classes also define - // members with attribute "AlwaysInline" and expect no reference to - // be generated. It is desirable to reenable this optimisation after - // corresponding LLVM changes. - addReplacement(MangledName, Aliasee); - return false; - } - - // If we have a weak, non-discardable alias (weak, weak_odr), like an extern - // template instantiation or a dllexported class, avoid forming it on COFF. - // A COFF weak external alias cannot satisfy a normal undefined symbol - // reference from another TU. The other TU must also mark the referenced - // symbol as weak, which we cannot rely on. - if (llvm::GlobalValue::isWeakForLinker(Linkage) && - getTriple().isOSBinFormatCOFF()) { - return true; - } - - // If we don't have a definition for the destructor yet or the definition is - // avaialable_externally, don't emit an alias. We can't emit aliases to - // declarations; that's just not how aliases work. - if (Ref->isDeclarationForLinker()) - return true; - - // Don't create an alias to a linker weak symbol. This avoids producing - // different COMDATs in different TUs. Another option would be to - // output the alias both for weak_odr and linkonce_odr, but that - // requires explicit comdat support in the IL. - if (llvm::GlobalValue::isWeakForLinker(TargetLinkage)) - return true; - - // Create the alias with no name. - auto *Alias = llvm::GlobalAlias::create(AliasValueType, 0, Linkage, "", - Aliasee, &getModule()); - - // Destructors are always unnamed_addr. - Alias->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global); - - // Switch any previous uses to the alias. - if (Entry) { - assert(Entry->getType() == AliasType && - "declaration exists with different type"); - Alias->takeName(Entry); - Entry->replaceAllUsesWith(Alias); - Entry->eraseFromParent(); - } else { - Alias->setName(MangledName); - } - - // Finally, set up the alias with its proper name and attributes. - SetCommonAttributes(AliasDecl, Alias); - - return false; -} - -llvm::Function *CodeGenModule::codegenCXXStructor(const CXXMethodDecl *MD, - StructorType Type) { - const CGFunctionInfo &FnInfo = - getTypes().arrangeCXXStructorDeclaration(MD, Type); - auto *Fn = cast<llvm::Function>( - getAddrOfCXXStructor(MD, Type, &FnInfo, /*FnType=*/nullptr, - /*DontDefer=*/true, ForDefinition)); - - GlobalDecl GD; - if (const auto *DD = dyn_cast<CXXDestructorDecl>(MD)) { - GD = GlobalDecl(DD, toCXXDtorType(Type)); - } else { - const auto *CD = cast<CXXConstructorDecl>(MD); - GD = GlobalDecl(CD, toCXXCtorType(Type)); - } - - setFunctionLinkage(GD, Fn); - - CodeGenFunction(*this).GenerateCode(GD, Fn, FnInfo); - setNonAliasAttributes(GD, Fn); - SetLLVMFunctionAttributesForDefinition(MD, Fn); - return Fn; -} - -llvm::Constant *CodeGenModule::getAddrOfCXXStructor( - const CXXMethodDecl *MD, StructorType Type, const CGFunctionInfo *FnInfo, - llvm::FunctionType *FnType, bool DontDefer, - ForDefinition_t IsForDefinition) { - GlobalDecl GD; - if (auto *CD = dyn_cast<CXXConstructorDecl>(MD)) { - GD = GlobalDecl(CD, toCXXCtorType(Type)); - } else { - // Always alias equivalent complete destructors to base destructors in the - // MS ABI. - if (getTarget().getCXXABI().isMicrosoft() && - Type == StructorType::Complete && MD->getParent()->getNumVBases() == 0) - Type = StructorType::Base; - GD = GlobalDecl(cast<CXXDestructorDecl>(MD), toCXXDtorType(Type)); - } - - if (!FnType) { - if (!FnInfo) - FnInfo = &getTypes().arrangeCXXStructorDeclaration(MD, Type); - FnType = getTypes().GetFunctionType(*FnInfo); - } - - return GetOrCreateLLVMFunction( - getMangledName(GD), FnType, GD, /*ForVTable=*/false, DontDefer, - /*isThunk=*/false, /*ExtraAttrs=*/llvm::AttributeList(), IsForDefinition); -} - -static CGCallee BuildAppleKextVirtualCall(CodeGenFunction &CGF, - GlobalDecl GD, - llvm::Type *Ty, - const CXXRecordDecl *RD) { - assert(!CGF.CGM.getTarget().getCXXABI().isMicrosoft() && - "No kext in Microsoft ABI"); - CodeGenModule &CGM = CGF.CGM; - llvm::Value *VTable = CGM.getCXXABI().getAddrOfVTable(RD, CharUnits()); - Ty = Ty->getPointerTo()->getPointerTo(); - VTable = CGF.Builder.CreateBitCast(VTable, Ty); - assert(VTable && "BuildVirtualCall = kext vtbl pointer is null"); - uint64_t VTableIndex = CGM.getItaniumVTableContext().getMethodVTableIndex(GD); - const VTableLayout &VTLayout = CGM.getItaniumVTableContext().getVTableLayout(RD); - VTableLayout::AddressPointLocation AddressPoint = - VTLayout.getAddressPoint(BaseSubobject(RD, CharUnits::Zero())); - VTableIndex += VTLayout.getVTableOffset(AddressPoint.VTableIndex) + - AddressPoint.AddressPointIndex; - llvm::Value *VFuncPtr = - CGF.Builder.CreateConstInBoundsGEP1_64(VTable, VTableIndex, "vfnkxt"); - llvm::Value *VFunc = - CGF.Builder.CreateAlignedLoad(VFuncPtr, CGF.PointerAlignInBytes); - CGCallee Callee(GD, VFunc); - return Callee; -} - -/// BuildAppleKextVirtualCall - This routine is to support gcc's kext ABI making -/// indirect call to virtual functions. It makes the call through indexing -/// into the vtable. -CGCallee -CodeGenFunction::BuildAppleKextVirtualCall(const CXXMethodDecl *MD, - NestedNameSpecifier *Qual, - llvm::Type *Ty) { - assert((Qual->getKind() == NestedNameSpecifier::TypeSpec) && - "BuildAppleKextVirtualCall - bad Qual kind"); - - const Type *QTy = Qual->getAsType(); - QualType T = QualType(QTy, 0); - const RecordType *RT = T->getAs<RecordType>(); - assert(RT && "BuildAppleKextVirtualCall - Qual type must be record"); - const auto *RD = cast<CXXRecordDecl>(RT->getDecl()); - - if (const auto *DD = dyn_cast<CXXDestructorDecl>(MD)) - return BuildAppleKextVirtualDestructorCall(DD, Dtor_Complete, RD); - - return ::BuildAppleKextVirtualCall(*this, MD, Ty, RD); -} - -/// BuildVirtualCall - This routine makes indirect vtable call for -/// call to virtual destructors. It returns 0 if it could not do it. -CGCallee -CodeGenFunction::BuildAppleKextVirtualDestructorCall( - const CXXDestructorDecl *DD, - CXXDtorType Type, - const CXXRecordDecl *RD) { - assert(DD->isVirtual() && Type != Dtor_Base); - // Compute the function type we're calling. - const CGFunctionInfo &FInfo = CGM.getTypes().arrangeCXXStructorDeclaration( - DD, StructorType::Complete); - llvm::Type *Ty = CGM.getTypes().GetFunctionType(FInfo); - return ::BuildAppleKextVirtualCall(*this, GlobalDecl(DD, Type), Ty, RD); -} |