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-rw-r--r--contrib/llvm/tools/clang/lib/CodeGen/CGDeclCXX.cpp522
1 files changed, 522 insertions, 0 deletions
diff --git a/contrib/llvm/tools/clang/lib/CodeGen/CGDeclCXX.cpp b/contrib/llvm/tools/clang/lib/CodeGen/CGDeclCXX.cpp
new file mode 100644
index 0000000..7bdb9eb
--- /dev/null
+++ b/contrib/llvm/tools/clang/lib/CodeGen/CGDeclCXX.cpp
@@ -0,0 +1,522 @@
+//===--- CGDeclCXX.cpp - Emit LLVM Code for C++ 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 code generation of C++ declarations
+//
+//===----------------------------------------------------------------------===//
+
+#include "CodeGenFunction.h"
+#include "CGCXXABI.h"
+#include "CGObjCRuntime.h"
+#include "clang/Frontend/CodeGenOptions.h"
+#include "llvm/ADT/StringExtras.h"
+#include "llvm/IR/Intrinsics.h"
+
+using namespace clang;
+using namespace CodeGen;
+
+static void EmitDeclInit(CodeGenFunction &CGF, const VarDecl &D,
+ llvm::Constant *DeclPtr) {
+ assert(D.hasGlobalStorage() && "VarDecl must have global storage!");
+ assert(!D.getType()->isReferenceType() &&
+ "Should not call EmitDeclInit on a reference!");
+
+ ASTContext &Context = CGF.getContext();
+
+ CharUnits alignment = Context.getDeclAlign(&D);
+ QualType type = D.getType();
+ LValue lv = CGF.MakeAddrLValue(DeclPtr, type, alignment);
+
+ const Expr *Init = D.getInit();
+ switch (CGF.getEvaluationKind(type)) {
+ case TEK_Scalar: {
+ CodeGenModule &CGM = CGF.CGM;
+ if (lv.isObjCStrong())
+ CGM.getObjCRuntime().EmitObjCGlobalAssign(CGF, CGF.EmitScalarExpr(Init),
+ DeclPtr, D.getTLSKind());
+ else if (lv.isObjCWeak())
+ CGM.getObjCRuntime().EmitObjCWeakAssign(CGF, CGF.EmitScalarExpr(Init),
+ DeclPtr);
+ else
+ CGF.EmitScalarInit(Init, &D, lv, false);
+ return;
+ }
+ case TEK_Complex:
+ CGF.EmitComplexExprIntoLValue(Init, lv, /*isInit*/ true);
+ return;
+ case TEK_Aggregate:
+ CGF.EmitAggExpr(Init, AggValueSlot::forLValue(lv,AggValueSlot::IsDestructed,
+ AggValueSlot::DoesNotNeedGCBarriers,
+ AggValueSlot::IsNotAliased));
+ return;
+ }
+ llvm_unreachable("bad evaluation kind");
+}
+
+/// Emit code to cause the destruction of the given variable with
+/// static storage duration.
+static void EmitDeclDestroy(CodeGenFunction &CGF, const VarDecl &D,
+ llvm::Constant *addr) {
+ CodeGenModule &CGM = CGF.CGM;
+
+ // FIXME: __attribute__((cleanup)) ?
+
+ QualType type = D.getType();
+ QualType::DestructionKind dtorKind = type.isDestructedType();
+
+ switch (dtorKind) {
+ case QualType::DK_none:
+ return;
+
+ case QualType::DK_cxx_destructor:
+ break;
+
+ case QualType::DK_objc_strong_lifetime:
+ case QualType::DK_objc_weak_lifetime:
+ // We don't care about releasing objects during process teardown.
+ assert(!D.getTLSKind() && "should have rejected this");
+ return;
+ }
+
+ llvm::Constant *function;
+ llvm::Constant *argument;
+
+ // Special-case non-array C++ destructors, where there's a function
+ // with the right signature that we can just call.
+ const CXXRecordDecl *record = 0;
+ if (dtorKind == QualType::DK_cxx_destructor &&
+ (record = type->getAsCXXRecordDecl())) {
+ assert(!record->hasTrivialDestructor());
+ CXXDestructorDecl *dtor = record->getDestructor();
+
+ function = CGM.GetAddrOfCXXDestructor(dtor, Dtor_Complete);
+ argument = llvm::ConstantExpr::getBitCast(
+ addr, CGF.getTypes().ConvertType(type)->getPointerTo());
+
+ // Otherwise, the standard logic requires a helper function.
+ } else {
+ function = CodeGenFunction(CGM)
+ .generateDestroyHelper(addr, type, CGF.getDestroyer(dtorKind),
+ CGF.needsEHCleanup(dtorKind), &D);
+ argument = llvm::Constant::getNullValue(CGF.Int8PtrTy);
+ }
+
+ CGM.getCXXABI().registerGlobalDtor(CGF, D, function, argument);
+}
+
+/// Emit code to cause the variable at the given address to be considered as
+/// constant from this point onwards.
+static void EmitDeclInvariant(CodeGenFunction &CGF, const VarDecl &D,
+ llvm::Constant *Addr) {
+ // Don't emit the intrinsic if we're not optimizing.
+ if (!CGF.CGM.getCodeGenOpts().OptimizationLevel)
+ return;
+
+ // Grab the llvm.invariant.start intrinsic.
+ llvm::Intrinsic::ID InvStartID = llvm::Intrinsic::invariant_start;
+ llvm::Constant *InvariantStart = CGF.CGM.getIntrinsic(InvStartID);
+
+ // Emit a call with the size in bytes of the object.
+ CharUnits WidthChars = CGF.getContext().getTypeSizeInChars(D.getType());
+ uint64_t Width = WidthChars.getQuantity();
+ llvm::Value *Args[2] = { llvm::ConstantInt::getSigned(CGF.Int64Ty, Width),
+ llvm::ConstantExpr::getBitCast(Addr, CGF.Int8PtrTy)};
+ CGF.Builder.CreateCall(InvariantStart, Args);
+}
+
+void CodeGenFunction::EmitCXXGlobalVarDeclInit(const VarDecl &D,
+ llvm::Constant *DeclPtr,
+ bool PerformInit) {
+
+ const Expr *Init = D.getInit();
+ QualType T = D.getType();
+
+ if (!T->isReferenceType()) {
+ if (PerformInit)
+ EmitDeclInit(*this, D, DeclPtr);
+ if (CGM.isTypeConstant(D.getType(), true))
+ EmitDeclInvariant(*this, D, DeclPtr);
+ else
+ EmitDeclDestroy(*this, D, DeclPtr);
+ return;
+ }
+
+ assert(PerformInit && "cannot have constant initializer which needs "
+ "destruction for reference");
+ unsigned Alignment = getContext().getDeclAlign(&D).getQuantity();
+ RValue RV = EmitReferenceBindingToExpr(Init);
+ EmitStoreOfScalar(RV.getScalarVal(), DeclPtr, false, Alignment, T);
+}
+
+static llvm::Function *
+CreateGlobalInitOrDestructFunction(CodeGenModule &CGM,
+ llvm::FunctionType *ty,
+ const Twine &name,
+ bool TLS = false);
+
+/// Create a stub function, suitable for being passed to atexit,
+/// which passes the given address to the given destructor function.
+static llvm::Constant *createAtExitStub(CodeGenModule &CGM, const VarDecl &VD,
+ llvm::Constant *dtor,
+ llvm::Constant *addr) {
+ // Get the destructor function type, void(*)(void).
+ llvm::FunctionType *ty = llvm::FunctionType::get(CGM.VoidTy, false);
+ SmallString<256> FnName;
+ {
+ llvm::raw_svector_ostream Out(FnName);
+ CGM.getCXXABI().getMangleContext().mangleDynamicAtExitDestructor(&VD, Out);
+ }
+ llvm::Function *fn =
+ CreateGlobalInitOrDestructFunction(CGM, ty, FnName.str());
+
+ CodeGenFunction CGF(CGM);
+
+ CGF.StartFunction(&VD, CGM.getContext().VoidTy, fn,
+ CGM.getTypes().arrangeNullaryFunction(), FunctionArgList(),
+ SourceLocation());
+
+ llvm::CallInst *call = CGF.Builder.CreateCall(dtor, addr);
+
+ // Make sure the call and the callee agree on calling convention.
+ if (llvm::Function *dtorFn =
+ dyn_cast<llvm::Function>(dtor->stripPointerCasts()))
+ call->setCallingConv(dtorFn->getCallingConv());
+
+ CGF.FinishFunction();
+
+ return fn;
+}
+
+/// Register a global destructor using the C atexit runtime function.
+void CodeGenFunction::registerGlobalDtorWithAtExit(const VarDecl &VD,
+ llvm::Constant *dtor,
+ llvm::Constant *addr) {
+ // Create a function which calls the destructor.
+ llvm::Constant *dtorStub = createAtExitStub(CGM, VD, dtor, addr);
+
+ // extern "C" int atexit(void (*f)(void));
+ llvm::FunctionType *atexitTy =
+ llvm::FunctionType::get(IntTy, dtorStub->getType(), false);
+
+ llvm::Constant *atexit =
+ CGM.CreateRuntimeFunction(atexitTy, "atexit");
+ if (llvm::Function *atexitFn = dyn_cast<llvm::Function>(atexit))
+ atexitFn->setDoesNotThrow();
+
+ EmitNounwindRuntimeCall(atexit, dtorStub);
+}
+
+void CodeGenFunction::EmitCXXGuardedInit(const VarDecl &D,
+ llvm::GlobalVariable *DeclPtr,
+ bool PerformInit) {
+ // If we've been asked to forbid guard variables, emit an error now.
+ // This diagnostic is hard-coded for Darwin's use case; we can find
+ // better phrasing if someone else needs it.
+ if (CGM.getCodeGenOpts().ForbidGuardVariables)
+ CGM.Error(D.getLocation(),
+ "this initialization requires a guard variable, which "
+ "the kernel does not support");
+
+ CGM.getCXXABI().EmitGuardedInit(*this, D, DeclPtr, PerformInit);
+}
+
+static llvm::Function *
+CreateGlobalInitOrDestructFunction(CodeGenModule &CGM,
+ llvm::FunctionType *FTy,
+ const Twine &Name, bool TLS) {
+ llvm::Function *Fn =
+ llvm::Function::Create(FTy, llvm::GlobalValue::InternalLinkage,
+ Name, &CGM.getModule());
+ if (!CGM.getLangOpts().AppleKext && !TLS) {
+ // Set the section if needed.
+ if (const char *Section =
+ CGM.getTarget().getStaticInitSectionSpecifier())
+ Fn->setSection(Section);
+ }
+
+ Fn->setCallingConv(CGM.getRuntimeCC());
+
+ if (!CGM.getLangOpts().Exceptions)
+ Fn->setDoesNotThrow();
+
+ if (CGM.getSanOpts().Address)
+ Fn->addFnAttr(llvm::Attribute::SanitizeAddress);
+ if (CGM.getSanOpts().Thread)
+ Fn->addFnAttr(llvm::Attribute::SanitizeThread);
+ if (CGM.getSanOpts().Memory)
+ Fn->addFnAttr(llvm::Attribute::SanitizeMemory);
+
+ return Fn;
+}
+
+void
+CodeGenModule::EmitCXXGlobalVarDeclInitFunc(const VarDecl *D,
+ llvm::GlobalVariable *Addr,
+ bool PerformInit) {
+ llvm::FunctionType *FTy = llvm::FunctionType::get(VoidTy, false);
+ SmallString<256> FnName;
+ {
+ llvm::raw_svector_ostream Out(FnName);
+ getCXXABI().getMangleContext().mangleDynamicInitializer(D, Out);
+ }
+
+ // Create a variable initialization function.
+ llvm::Function *Fn =
+ CreateGlobalInitOrDestructFunction(*this, FTy, FnName.str());
+
+ CodeGenFunction(*this).GenerateCXXGlobalVarDeclInitFunc(Fn, D, Addr,
+ PerformInit);
+
+ if (D->getTLSKind()) {
+ // FIXME: Should we support init_priority for thread_local?
+ // FIXME: Ideally, initialization of instantiated thread_local static data
+ // members of class templates should not trigger initialization of other
+ // entities in the TU.
+ // FIXME: We only need to register one __cxa_thread_atexit function for the
+ // entire TU.
+ CXXThreadLocalInits.push_back(Fn);
+ } else if (D->hasAttr<InitPriorityAttr>()) {
+ unsigned int order = D->getAttr<InitPriorityAttr>()->getPriority();
+ OrderGlobalInits Key(order, PrioritizedCXXGlobalInits.size());
+ PrioritizedCXXGlobalInits.push_back(std::make_pair(Key, Fn));
+ DelayedCXXInitPosition.erase(D);
+ } else if (D->getTemplateSpecializationKind() != TSK_ExplicitSpecialization &&
+ D->getTemplateSpecializationKind() != TSK_Undeclared) {
+ // C++ [basic.start.init]p2:
+ // Definitions of explicitly specialized class template static data
+ // members have ordered initialization. Other class template static data
+ // members (i.e., implicitly or explicitly instantiated specializations)
+ // have unordered initialization.
+ //
+ // As a consequence, we can put them into their own llvm.global_ctors entry.
+ // This should allow GlobalOpt to fire more often, and allow us to implement
+ // the Microsoft C++ ABI, which uses COMDAT elimination to avoid double
+ // initializaiton.
+ AddGlobalCtor(Fn);
+ DelayedCXXInitPosition.erase(D);
+ } else {
+ llvm::DenseMap<const Decl *, unsigned>::iterator I =
+ DelayedCXXInitPosition.find(D);
+ if (I == DelayedCXXInitPosition.end()) {
+ CXXGlobalInits.push_back(Fn);
+ } else {
+ assert(CXXGlobalInits[I->second] == 0);
+ CXXGlobalInits[I->second] = Fn;
+ DelayedCXXInitPosition.erase(I);
+ }
+ }
+}
+
+void CodeGenModule::EmitCXXThreadLocalInitFunc() {
+ llvm::Function *InitFn = 0;
+ if (!CXXThreadLocalInits.empty()) {
+ // Generate a guarded initialization function.
+ llvm::FunctionType *FTy = llvm::FunctionType::get(VoidTy, false);
+ InitFn = CreateGlobalInitOrDestructFunction(*this, FTy, "__tls_init",
+ /*TLS*/ true);
+ llvm::GlobalVariable *Guard = new llvm::GlobalVariable(
+ getModule(), Int8Ty, false, llvm::GlobalVariable::InternalLinkage,
+ llvm::ConstantInt::get(Int8Ty, 0), "__tls_guard");
+ Guard->setThreadLocal(true);
+ CodeGenFunction(*this)
+ .GenerateCXXGlobalInitFunc(InitFn, CXXThreadLocalInits, Guard);
+ }
+
+ getCXXABI().EmitThreadLocalInitFuncs(CXXThreadLocals, InitFn);
+
+ CXXThreadLocalInits.clear();
+ CXXThreadLocals.clear();
+}
+
+void
+CodeGenModule::EmitCXXGlobalInitFunc() {
+ while (!CXXGlobalInits.empty() && !CXXGlobalInits.back())
+ CXXGlobalInits.pop_back();
+
+ if (CXXGlobalInits.empty() && PrioritizedCXXGlobalInits.empty())
+ return;
+
+ llvm::FunctionType *FTy = llvm::FunctionType::get(VoidTy, false);
+
+
+ // Create our global initialization function.
+ if (!PrioritizedCXXGlobalInits.empty()) {
+ SmallVector<llvm::Constant*, 8> LocalCXXGlobalInits;
+ llvm::array_pod_sort(PrioritizedCXXGlobalInits.begin(),
+ PrioritizedCXXGlobalInits.end());
+ // Iterate over "chunks" of ctors with same priority and emit each chunk
+ // into separate function. Note - everything is sorted first by priority,
+ // second - by lex order, so we emit ctor functions in proper order.
+ for (SmallVectorImpl<GlobalInitData >::iterator
+ I = PrioritizedCXXGlobalInits.begin(),
+ E = PrioritizedCXXGlobalInits.end(); I != E; ) {
+ SmallVectorImpl<GlobalInitData >::iterator
+ PrioE = std::upper_bound(I + 1, E, *I, GlobalInitPriorityCmp());
+
+ LocalCXXGlobalInits.clear();
+ unsigned Priority = I->first.priority;
+ // Compute the function suffix from priority. Prepend with zeroes to make
+ // sure the function names are also ordered as priorities.
+ std::string PrioritySuffix = llvm::utostr(Priority);
+ // Priority is always <= 65535 (enforced by sema)..
+ PrioritySuffix = std::string(6-PrioritySuffix.size(), '0')+PrioritySuffix;
+ llvm::Function *Fn =
+ CreateGlobalInitOrDestructFunction(*this, FTy,
+ "_GLOBAL__I_" + PrioritySuffix);
+
+ for (; I < PrioE; ++I)
+ LocalCXXGlobalInits.push_back(I->second);
+
+ CodeGenFunction(*this).GenerateCXXGlobalInitFunc(Fn, LocalCXXGlobalInits);
+ AddGlobalCtor(Fn, Priority);
+ }
+ }
+
+ llvm::Function *Fn =
+ CreateGlobalInitOrDestructFunction(*this, FTy, "_GLOBAL__I_a");
+
+ CodeGenFunction(*this).GenerateCXXGlobalInitFunc(Fn, CXXGlobalInits);
+ AddGlobalCtor(Fn);
+
+ CXXGlobalInits.clear();
+ PrioritizedCXXGlobalInits.clear();
+}
+
+void CodeGenModule::EmitCXXGlobalDtorFunc() {
+ if (CXXGlobalDtors.empty())
+ return;
+
+ llvm::FunctionType *FTy = llvm::FunctionType::get(VoidTy, false);
+
+ // Create our global destructor function.
+ llvm::Function *Fn =
+ CreateGlobalInitOrDestructFunction(*this, FTy, "_GLOBAL__D_a");
+
+ CodeGenFunction(*this).GenerateCXXGlobalDtorsFunc(Fn, CXXGlobalDtors);
+ AddGlobalDtor(Fn);
+}
+
+/// Emit the code necessary to initialize the given global variable.
+void CodeGenFunction::GenerateCXXGlobalVarDeclInitFunc(llvm::Function *Fn,
+ const VarDecl *D,
+ llvm::GlobalVariable *Addr,
+ bool PerformInit) {
+ // Check if we need to emit debug info for variable initializer.
+ if (D->hasAttr<NoDebugAttr>())
+ DebugInfo = NULL; // disable debug info indefinitely for this function
+
+ StartFunction(GlobalDecl(D), getContext().VoidTy, Fn,
+ getTypes().arrangeNullaryFunction(),
+ FunctionArgList(), D->getInit()->getExprLoc());
+
+ // Use guarded initialization if the global variable is weak. This
+ // occurs for, e.g., instantiated static data members and
+ // definitions explicitly marked weak.
+ if (Addr->getLinkage() == llvm::GlobalValue::WeakODRLinkage ||
+ Addr->getLinkage() == llvm::GlobalValue::WeakAnyLinkage) {
+ EmitCXXGuardedInit(*D, Addr, PerformInit);
+ } else {
+ EmitCXXGlobalVarDeclInit(*D, Addr, PerformInit);
+ }
+
+ FinishFunction();
+}
+
+void
+CodeGenFunction::GenerateCXXGlobalInitFunc(llvm::Function *Fn,
+ ArrayRef<llvm::Constant *> Decls,
+ llvm::GlobalVariable *Guard) {
+ StartFunction(GlobalDecl(), getContext().VoidTy, Fn,
+ getTypes().arrangeNullaryFunction(),
+ FunctionArgList(), SourceLocation());
+
+ llvm::BasicBlock *ExitBlock = 0;
+ if (Guard) {
+ // If we have a guard variable, check whether we've already performed these
+ // initializations. This happens for TLS initialization functions.
+ llvm::Value *GuardVal = Builder.CreateLoad(Guard);
+ llvm::Value *Uninit = Builder.CreateIsNull(GuardVal, "guard.uninitialized");
+ // Mark as initialized before initializing anything else. If the
+ // initializers use previously-initialized thread_local vars, that's
+ // probably supposed to be OK, but the standard doesn't say.
+ Builder.CreateStore(llvm::ConstantInt::get(GuardVal->getType(), 1), Guard);
+ llvm::BasicBlock *InitBlock = createBasicBlock("init");
+ ExitBlock = createBasicBlock("exit");
+ Builder.CreateCondBr(Uninit, InitBlock, ExitBlock);
+ EmitBlock(InitBlock);
+ }
+
+ RunCleanupsScope Scope(*this);
+
+ // When building in Objective-C++ ARC mode, create an autorelease pool
+ // around the global initializers.
+ if (getLangOpts().ObjCAutoRefCount && getLangOpts().CPlusPlus) {
+ llvm::Value *token = EmitObjCAutoreleasePoolPush();
+ EmitObjCAutoreleasePoolCleanup(token);
+ }
+
+ for (unsigned i = 0, e = Decls.size(); i != e; ++i)
+ if (Decls[i])
+ EmitRuntimeCall(Decls[i]);
+
+ Scope.ForceCleanup();
+
+ if (ExitBlock) {
+ Builder.CreateBr(ExitBlock);
+ EmitBlock(ExitBlock);
+ }
+
+ FinishFunction();
+}
+
+void CodeGenFunction::GenerateCXXGlobalDtorsFunc(llvm::Function *Fn,
+ const std::vector<std::pair<llvm::WeakVH, llvm::Constant*> >
+ &DtorsAndObjects) {
+ StartFunction(GlobalDecl(), getContext().VoidTy, Fn,
+ getTypes().arrangeNullaryFunction(),
+ FunctionArgList(), SourceLocation());
+
+ // Emit the dtors, in reverse order from construction.
+ for (unsigned i = 0, e = DtorsAndObjects.size(); i != e; ++i) {
+ llvm::Value *Callee = DtorsAndObjects[e - i - 1].first;
+ llvm::CallInst *CI = Builder.CreateCall(Callee,
+ DtorsAndObjects[e - i - 1].second);
+ // Make sure the call and the callee agree on calling convention.
+ if (llvm::Function *F = dyn_cast<llvm::Function>(Callee))
+ CI->setCallingConv(F->getCallingConv());
+ }
+
+ FinishFunction();
+}
+
+/// generateDestroyHelper - Generates a helper function which, when
+/// invoked, destroys the given object.
+llvm::Function *CodeGenFunction::generateDestroyHelper(
+ llvm::Constant *addr, QualType type, Destroyer *destroyer,
+ bool useEHCleanupForArray, const VarDecl *VD) {
+ FunctionArgList args;
+ ImplicitParamDecl dst(0, SourceLocation(), 0, getContext().VoidPtrTy);
+ args.push_back(&dst);
+
+ const CGFunctionInfo &FI =
+ CGM.getTypes().arrangeFunctionDeclaration(getContext().VoidTy, args,
+ FunctionType::ExtInfo(),
+ /*variadic*/ false);
+ llvm::FunctionType *FTy = CGM.getTypes().GetFunctionType(FI);
+ llvm::Function *fn =
+ CreateGlobalInitOrDestructFunction(CGM, FTy, "__cxx_global_array_dtor");
+
+ StartFunction(VD, getContext().VoidTy, fn, FI, args, SourceLocation());
+
+ emitDestroy(addr, type, destroyer, useEHCleanupForArray);
+
+ FinishFunction();
+
+ return fn;
+}
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