mirrors/llvm-project
0
0
Fork 0
mirror of https://github.com/llvm/llvm-project.git synced 2025-05-17 22:06:06 +00:00
Code Issues Projects Releases Wiki Activity
llvm-project/clang/lib/CodeGen/CGDeclCXX.cpp
Vlad Tsyrklevich 2eccdab308 Allow specifying sanitizers in blacklists 
Summary:
This is the follow-up patch to D37924.

This change refactors clang to use the the newly added section headers
in SpecialCaseList to specify which sanitizers blacklists entries
should apply to, like so:

  [cfi-vcall]
  fun:*bad_vcall*
  [cfi-derived-cast|cfi-unrelated-cast]
  fun:*bad_cast*

The SanitizerSpecialCaseList class has been added to allow querying by
SanitizerMask, and SanitizerBlacklist and its downstream users have been
updated to provide that information. Old blacklists not using sections
will continue to function identically since the blacklist entries will
be placed into a '[*]' section by default matching against all
sanitizers.

Reviewers: pcc, kcc, eugenis, vsk

Reviewed By: eugenis

Subscribers: dberris, cfe-commits, mgorny

Differential Revision: https://reviews.llvm.org/D37925

llvm-svn: 314171
2017-09-25 22:11:12 +00:00

669 lines
26 KiB
C++
Raw Blame History

//===--- 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 "CGOpenMPRuntime.h"
#include "clang/Frontend/CodeGenOptions.h"
#include "llvm/ADT/StringExtras.h"
#include "llvm/IR/Intrinsics.h"
#include "llvm/IR/MDBuilder.h"
#include "llvm/Support/Path.h"
using namespace clang;
using namespace CodeGen;
static void EmitDeclInit(CodeGenFunction &CGF, const VarDecl &D,
ConstantAddress DeclPtr) {
assert(D.hasGlobalStorage() && "VarDecl must have global storage!");
assert(!D.getType()->isReferenceType() &&
"Should not call EmitDeclInit on a reference!");
QualType type = D.getType();
LValue lv = CGF.MakeAddrLValue(DeclPtr, type);
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,
ConstantAddress 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, if they have the right signature.
// Under some ABIs, destructors return this instead of void, and cannot be
// passed directly to __cxa_atexit if the target does not allow this mismatch.
const CXXRecordDecl *Record = type->getAsCXXRecordDecl();
bool CanRegisterDestructor =
Record && (!CGM.getCXXABI().HasThisReturn(
GlobalDecl(Record->getDestructor(), Dtor_Complete)) ||
CGM.getCXXABI().canCallMismatchedFunctionType());
// If __cxa_atexit is disabled via a flag, a different helper function is
// generated elsewhere which uses atexit instead, and it takes the destructor
// directly.
bool UsingExternalHelper = !CGM.getCodeGenOpts().CXAAtExit;
if (Record && (CanRegisterDestructor || UsingExternalHelper)) {
assert(!Record->hasTrivialDestructor());
CXXDestructorDecl *dtor = Record->getDestructor();
function = CGM.getAddrOfCXXStructor(dtor, StructorType::Complete);
argument = llvm::ConstantExpr::getBitCast(
addr.getPointer(), 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) {
// Do not 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;
// Overloaded address space type.
llvm::Type *ObjectPtr[1] = {CGF.Int8PtrTy};
llvm::Constant *InvariantStart = CGF.CGM.getIntrinsic(InvStartID, ObjectPtr);
// 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();
// The address space of a static local variable (DeclPtr) may be different
// from the address space of the "this" argument of the constructor. In that
// case, we need an addrspacecast before calling the constructor.
//
// struct StructWithCtor {
// __device__ StructWithCtor() {...}
// };
// __device__ void foo() {
// __shared__ StructWithCtor s;
// ...
// }
//
// For example, in the above CUDA code, the static local variable s has a
// "shared" address space qualifier, but the constructor of StructWithCtor
// expects "this" in the "generic" address space.
unsigned ExpectedAddrSpace = getContext().getTargetAddressSpace(T);
unsigned ActualAddrSpace = DeclPtr->getType()->getPointerAddressSpace();
if (ActualAddrSpace != ExpectedAddrSpace) {
llvm::Type *LTy = CGM.getTypes().ConvertTypeForMem(T);
llvm::PointerType *PTy = llvm::PointerType::get(LTy, ExpectedAddrSpace);
DeclPtr = llvm::ConstantExpr::getAddrSpaceCast(DeclPtr, PTy);
}
ConstantAddress DeclAddr(DeclPtr, getContext().getDeclAlign(&D));
if (!T->isReferenceType()) {
if (getLangOpts().OpenMP && D.hasAttr<OMPThreadPrivateDeclAttr>())
(void)CGM.getOpenMPRuntime().emitThreadPrivateVarDefinition(
&D, DeclAddr, D.getAttr<OMPThreadPrivateDeclAttr>()->getLocation(),
PerformInit, this);
if (PerformInit)
EmitDeclInit(*this, D, DeclAddr);
if (CGM.isTypeConstant(D.getType(), true))
EmitDeclInvariant(*this, D, DeclPtr);
else
EmitDeclDestroy(*this, D, DeclAddr);
return;
}
assert(PerformInit && "cannot have constant initializer which needs "
"destruction for reference");
RValue RV = EmitReferenceBindingToExpr(Init);
EmitStoreOfScalar(RV.getScalarVal(), DeclAddr, false, T);
}
/// Create a stub function, suitable for being passed to atexit,
/// which passes the given address to the given destructor function.
llvm::Constant *CodeGenFunction::createAtExitStub(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);
}
const CGFunctionInfo &FI = CGM.getTypes().arrangeNullaryFunction();
llvm::Function *fn = CGM.CreateGlobalInitOrDestructFunction(ty, FnName.str(),
FI,
VD.getLocation());
CodeGenFunction CGF(CGM);
CGF.StartFunction(&VD, CGM.getContext().VoidTy, fn, FI, FunctionArgList());
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(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", llvm::AttributeList(),
/*Local=*/true);
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);
}
void CodeGenFunction::EmitCXXGuardedInitBranch(llvm::Value *NeedsInit,
llvm::BasicBlock *InitBlock,
llvm::BasicBlock *NoInitBlock,
GuardKind Kind,
const VarDecl *D) {
assert((Kind == GuardKind::TlsGuard || D) && "no guarded variable");
// A guess at how many times we will enter the initialization of a
// variable, depending on the kind of variable.
static const uint64_t InitsPerTLSVar = 1024;
static const uint64_t InitsPerLocalVar = 1024 * 1024;
llvm::MDNode *Weights;
if (Kind == GuardKind::VariableGuard && !D->isLocalVarDecl()) {
// For non-local variables, don't apply any weighting for now. Due to our
// use of COMDATs, we expect there to be at most one initialization of the
// variable per DSO, but we have no way to know how many DSOs will try to
// initialize the variable.
Weights = nullptr;
} else {
uint64_t NumInits;
// FIXME: For the TLS case, collect and use profiling information to
// determine a more accurate brach weight.
if (Kind == GuardKind::TlsGuard || D->getTLSKind())
NumInits = InitsPerTLSVar;
else
NumInits = InitsPerLocalVar;
// The probability of us entering the initializer is
// 1 / (total number of times we attempt to initialize the variable).
llvm::MDBuilder MDHelper(CGM.getLLVMContext());
Weights = MDHelper.createBranchWeights(1, NumInits - 1);
}
Builder.CreateCondBr(NeedsInit, InitBlock, NoInitBlock, Weights);
}
llvm::Function *CodeGenModule::CreateGlobalInitOrDestructFunction(
llvm::FunctionType *FTy, const Twine &Name, const CGFunctionInfo &FI,
SourceLocation Loc, bool TLS) {
llvm::Function *Fn =
llvm::Function::Create(FTy, llvm::GlobalValue::InternalLinkage,
Name, &getModule());
if (!getLangOpts().AppleKext && !TLS) {
// Set the section if needed.
if (const char *Section = getTarget().getStaticInitSectionSpecifier())
Fn->setSection(Section);
}
SetInternalFunctionAttributes(nullptr, Fn, FI);
Fn->setCallingConv(getRuntimeCC());
if (!getLangOpts().Exceptions)
Fn->setDoesNotThrow();
if (getLangOpts().Sanitize.has(SanitizerKind::Address) &&
!isInSanitizerBlacklist(SanitizerKind::Address, Fn, Loc))
Fn->addFnAttr(llvm::Attribute::SanitizeAddress);
if (getLangOpts().Sanitize.has(SanitizerKind::KernelAddress) &&
!isInSanitizerBlacklist(SanitizerKind::KernelAddress, Fn, Loc))
Fn->addFnAttr(llvm::Attribute::SanitizeAddress);
if (getLangOpts().Sanitize.has(SanitizerKind::Thread) &&
!isInSanitizerBlacklist(SanitizerKind::Thread, Fn, Loc))
Fn->addFnAttr(llvm::Attribute::SanitizeThread);
if (getLangOpts().Sanitize.has(SanitizerKind::Memory) &&
!isInSanitizerBlacklist(SanitizerKind::Memory, Fn, Loc))
Fn->addFnAttr(llvm::Attribute::SanitizeMemory);
if (getLangOpts().Sanitize.has(SanitizerKind::SafeStack) &&
!isInSanitizerBlacklist(SanitizerKind::SafeStack, Fn, Loc))
Fn->addFnAttr(llvm::Attribute::SafeStack);
return Fn;
}
/// Create a global pointer to a function that will initialize a global
/// variable. The user has requested that this pointer be emitted in a specific
/// section.
void CodeGenModule::EmitPointerToInitFunc(const VarDecl *D,
llvm::GlobalVariable *GV,
llvm::Function *InitFunc,
InitSegAttr *ISA) {
llvm::GlobalVariable *PtrArray = new llvm::GlobalVariable(
TheModule, InitFunc->getType(), /*isConstant=*/true,
llvm::GlobalValue::PrivateLinkage, InitFunc, "__cxx_init_fn_ptr");
PtrArray->setSection(ISA->getSection());
addUsedGlobal(PtrArray);
// If the GV is already in a comdat group, then we have to join it.
if (llvm::Comdat *C = GV->getComdat())
PtrArray->setComdat(C);
}
void
CodeGenModule::EmitCXXGlobalVarDeclInitFunc(const VarDecl *D,
llvm::GlobalVariable *Addr,
bool PerformInit) {
// According to E.2.3.1 in CUDA-7.5 Programming guide: __device__,
// __constant__ and __shared__ variables defined in namespace scope,
// that are of class type, cannot have a non-empty constructor. All
// the checks have been done in Sema by now. Whatever initializers
// are allowed are empty and we just need to ignore them here.
if (getLangOpts().CUDA && getLangOpts().CUDAIsDevice &&
(D->hasAttr<CUDADeviceAttr>() || D->hasAttr<CUDAConstantAttr>() ||
D->hasAttr<CUDASharedAttr>()))
return;
// Check if we've already initialized this decl.
auto I = DelayedCXXInitPosition.find(D);
if (I != DelayedCXXInitPosition.end() && I->second == ~0U)
return;
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(FTy, FnName.str(),
getTypes().arrangeNullaryFunction(),
D->getLocation());
auto *ISA = D->getAttr<InitSegAttr>();
CodeGenFunction(*this).GenerateCXXGlobalVarDeclInitFunc(Fn, D, Addr,
PerformInit);
llvm::GlobalVariable *COMDATKey =
supportsCOMDAT() && D->isExternallyVisible() ? Addr : nullptr;
if (D->getTLSKind()) {
// FIXME: Should we support init_priority for thread_local?
// FIXME: We only need to register one __cxa_thread_atexit function for the
// entire TU.
CXXThreadLocalInits.push_back(Fn);
CXXThreadLocalInitVars.push_back(D);
} else if (PerformInit && ISA) {
EmitPointerToInitFunc(D, Addr, Fn, ISA);
} else if (auto *IPA = D->getAttr<InitPriorityAttr>()) {
OrderGlobalInits Key(IPA->getPriority(), PrioritizedCXXGlobalInits.size());
PrioritizedCXXGlobalInits.push_back(std::make_pair(Key, Fn));
} else if (isTemplateInstantiation(D->getTemplateSpecializationKind())) {
// 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.
//
// If the global is externally visible, put the initializer into a COMDAT
// group with the global being initialized. On most platforms, this is a
// minor startup time optimization. In the MS C++ ABI, there are no guard
// variables, so this COMDAT key is required for correctness.
AddGlobalCtor(Fn, 65535, COMDATKey);
} else if (D->hasAttr<SelectAnyAttr>()) {
// SelectAny globals will be comdat-folded. Put the initializer into a
// COMDAT group associated with the global, so the initializers get folded
// too.
AddGlobalCtor(Fn, 65535, COMDATKey);
} else {
I = DelayedCXXInitPosition.find(D); // Re-do lookup in case of re-hash.
if (I == DelayedCXXInitPosition.end()) {
CXXGlobalInits.push_back(Fn);
} else if (I->second != ~0U) {
assert(I->second < CXXGlobalInits.size() &&
CXXGlobalInits[I->second] == nullptr);
CXXGlobalInits[I->second] = Fn;
}
}
// Remember that we already emitted the initializer for this global.
DelayedCXXInitPosition[D] = ~0U;
}
void CodeGenModule::EmitCXXThreadLocalInitFunc() {
getCXXABI().EmitThreadLocalInitFuncs(
*this, CXXThreadLocals, CXXThreadLocalInits, CXXThreadLocalInitVars);
CXXThreadLocalInits.clear();
CXXThreadLocalInitVars.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);
const CGFunctionInfo &FI = getTypes().arrangeNullaryFunction();
// Create our global initialization function.
if (!PrioritizedCXXGlobalInits.empty()) {
SmallVector<llvm::Function *, 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(
FTy, "_GLOBAL__I_" + PrioritySuffix, FI);
for (; I < PrioE; ++I)
LocalCXXGlobalInits.push_back(I->second);
CodeGenFunction(*this).GenerateCXXGlobalInitFunc(Fn, LocalCXXGlobalInits);
AddGlobalCtor(Fn, Priority);
}
PrioritizedCXXGlobalInits.clear();
}
// Include the filename in the symbol name. Including "sub_" matches gcc and
// makes sure these symbols appear lexicographically behind the symbols with
// priority emitted above.
SmallString<128> FileName = llvm::sys::path::filename(getModule().getName());
if (FileName.empty())
FileName = "<null>";
for (size_t i = 0; i < FileName.size(); ++i) {
// Replace everything that's not [a-zA-Z0-9._] with a _. This set happens
// to be the set of C preprocessing numbers.
if (!isPreprocessingNumberBody(FileName[i]))
FileName[i] = '_';
}
llvm::Function *Fn = CreateGlobalInitOrDestructFunction(
FTy, llvm::Twine("_GLOBAL__sub_I_", FileName), FI);
CodeGenFunction(*this).GenerateCXXGlobalInitFunc(Fn, CXXGlobalInits);
AddGlobalCtor(Fn);
CXXGlobalInits.clear();
}
void CodeGenModule::EmitCXXGlobalDtorFunc() {
if (CXXGlobalDtors.empty())
return;
llvm::FunctionType *FTy = llvm::FunctionType::get(VoidTy, false);
// Create our global destructor function.
const CGFunctionInfo &FI = getTypes().arrangeNullaryFunction();
llvm::Function *Fn =
CreateGlobalInitOrDestructFunction(FTy, "_GLOBAL__D_a", FI);
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 = nullptr; // disable debug info indefinitely for this function
CurEHLocation = D->getLocStart();
StartFunction(GlobalDecl(D), getContext().VoidTy, Fn,
getTypes().arrangeNullaryFunction(),
FunctionArgList(), D->getLocation(),
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->hasWeakLinkage() || Addr->hasLinkOnceLinkage()) {
EmitCXXGuardedInit(*D, Addr, PerformInit);
} else {
EmitCXXGlobalVarDeclInit(*D, Addr, PerformInit);
}
FinishFunction();
}
void
CodeGenFunction::GenerateCXXGlobalInitFunc(llvm::Function *Fn,
ArrayRef<llvm::Function *> Decls,
Address Guard) {
{
auto NL = ApplyDebugLocation::CreateEmpty(*this);
StartFunction(GlobalDecl(), getContext().VoidTy, Fn,
getTypes().arrangeNullaryFunction(), FunctionArgList());
// Emit an artificial location for this function.
auto AL = ApplyDebugLocation::CreateArtificial(*this);
llvm::BasicBlock *ExitBlock = nullptr;
if (Guard.isValid()) {
// 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");
llvm::BasicBlock *InitBlock = createBasicBlock("init");
ExitBlock = createBasicBlock("exit");
EmitCXXGuardedInitBranch(Uninit, InitBlock, ExitBlock,
GuardKind::TlsGuard, nullptr);
EmitBlock(InitBlock);
// 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);
}
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::WeakTrackingVH, llvm::Constant *>>
&DtorsAndObjects) {
{
auto NL = ApplyDebugLocation::CreateEmpty(*this);
StartFunction(GlobalDecl(), getContext().VoidTy, Fn,
getTypes().arrangeNullaryFunction(), FunctionArgList());
// Emit an artificial location for this function.
auto AL = ApplyDebugLocation::CreateArtificial(*this);
// 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. The address of the object
/// should be in global memory.
llvm::Function *CodeGenFunction::generateDestroyHelper(
Address addr, QualType type, Destroyer *destroyer,
bool useEHCleanupForArray, const VarDecl *VD) {
FunctionArgList args;
ImplicitParamDecl Dst(getContext(), getContext().VoidPtrTy,
ImplicitParamDecl::Other);
args.push_back(&Dst);
const CGFunctionInfo &FI =
CGM.getTypes().arrangeBuiltinFunctionDeclaration(getContext().VoidTy, args);
llvm::FunctionType *FTy = CGM.getTypes().GetFunctionType(FI);
llvm::Function *fn = CGM.CreateGlobalInitOrDestructFunction(
FTy, "__cxx_global_array_dtor", FI, VD->getLocation());
CurEHLocation = VD->getLocStart();
StartFunction(VD, getContext().VoidTy, fn, FI, args);
emitDestroy(addr, type, destroyer, useEHCleanupForArray);
FinishFunction();
return fn;
}
Reference in New Issue View Git Blame Copy Permalink