/// Given a specified llvm.global_ctors list, remove the listed elements.
static void removeGlobalCtors(GlobalVariable *GCL, const BitVector &CtorsToRemove) {
// Filter out the initializer elements to remove.
ConstantArray *OldCA = cast<ConstantArray>(GCL->getInitializer());
SmallVector<Constant *, 10> CAList;
for (unsigned I = 0, E = OldCA->getNumOperands(); I < E; ++I)
if (!CtorsToRemove.test(I))
CAList.push_back(OldCA->getOperand(I));
// Create the new array initializer.
ArrayType *ATy =
ArrayType::get(OldCA->getType()->getElementType(), CAList.size());
Constant *CA = ConstantArray::get(ATy, CAList);
// If we didn't change the number of elements, don't create a new GV.
if (CA->getType() == OldCA->getType()) {
GCL->setInitializer(CA);
return;
}
// Create the new global and insert it next to the existing list.
GlobalVariable *NGV =
new GlobalVariable(CA->getType(), GCL->isConstant(), GCL->getLinkage(),
CA, "", GCL->getThreadLocalMode());
GCL->getParent()->getGlobalList().insert(GCL->getIterator(), NGV);
NGV->takeName(GCL);
// Nuke the old list, replacing any uses with the new one.
if (!GCL->use_empty()) {
Constant *V = NGV;
if (V->getType() != GCL->getType())
V = ConstantExpr::getBitCast(V, GCL->getType());
GCL->replaceAllUsesWith(V);
}
GCL->eraseFromParent();
}
void Variables::changeGlobal(Change* change, Module &module) {
GlobalValue* oldTarget = dyn_cast<GlobalValue>(change->getValue());
Type* oldType = oldTarget->getType()->getElementType();
Type* newType = change->getType()[0];
errs() << "Changing the precision of variable \"" << oldTarget->getName() << "\" from " << *oldType << " to " << *newType << ".\n";
if (diffTypes(oldType, newType)) {
Constant *initializer;
GlobalVariable* newTarget;
if (PointerType *newPointerType = dyn_cast<PointerType>(newType)) {
initializer = ConstantPointerNull::get(newPointerType);
newTarget = new GlobalVariable(module, newType, false, GlobalValue::CommonLinkage, initializer, "");
}
else if (ArrayType * atype = dyn_cast<ArrayType>(newType)) {
// preparing initializer
Type *temp = Type::getFloatTy(module.getContext());
vector<Constant*> operands;
operands.push_back(ConstantFP::get(temp, 0));
ArrayRef<Constant*> *arrayRef = new ArrayRef<Constant*>(operands);
initializer = ConstantArray::get(atype, *arrayRef);
newTarget = new GlobalVariable(module, newType, false, GlobalValue::CommonLinkage, initializer, "");
}
else {
initializer = ConstantFP::get(newType, 0);
newTarget = new GlobalVariable(module, newType, false, GlobalValue::CommonLinkage, initializer, "");
}
/*
GlobalVariable* newTarget = new GlobalVariable(module, newType, false, GlobalValue::CommonLinkage, initializer, "");
*/
unsigned alignment = getAlignment(newType);
newTarget->setAlignment(alignment);
newTarget->takeName(oldTarget);
// iterating through instructions using old AllocaInst
Value::use_iterator it = oldTarget->use_begin();
for(; it != oldTarget->use_end(); it++) {
Transformer::transform(it, newTarget, oldTarget, newType, oldType, alignment);
}
//oldTarget->eraseFromParent();
}
else {
errs() << "No changes required.\n";
}
return;
}
bool XCoreLowerThreadLocal::lowerGlobal(GlobalVariable *GV) {
Module *M = GV->getParent();
LLVMContext &Ctx = M->getContext();
if (!GV->isThreadLocal())
return false;
// Skip globals that we can't lower and leave it for the backend to error.
if (!rewriteNonInstructionUses(GV, this) ||
!GV->getType()->isSized() || isZeroLengthArray(GV->getType()))
return false;
// Create replacement global.
ArrayType *NewType = createLoweredType(GV->getType()->getElementType());
Constant *NewInitializer = nullptr;
if (GV->hasInitializer())
NewInitializer = createLoweredInitializer(NewType,
GV->getInitializer());
GlobalVariable *NewGV =
new GlobalVariable(*M, NewType, GV->isConstant(), GV->getLinkage(),
NewInitializer, "", nullptr,
GlobalVariable::NotThreadLocal,
GV->getType()->getAddressSpace(),
GV->isExternallyInitialized());
// Update uses.
SmallVector<User *, 16> Users(GV->user_begin(), GV->user_end());
for (unsigned I = 0, E = Users.size(); I != E; ++I) {
User *U = Users[I];
Instruction *Inst = cast<Instruction>(U);
IRBuilder<> Builder(Inst);
Function *GetID = Intrinsic::getDeclaration(GV->getParent(),
Intrinsic::xcore_getid);
Value *ThreadID = Builder.CreateCall(GetID);
SmallVector<Value *, 2> Indices;
Indices.push_back(Constant::getNullValue(Type::getInt64Ty(Ctx)));
Indices.push_back(ThreadID);
Value *Addr =
Builder.CreateInBoundsGEP(NewGV->getValueType(), NewGV, Indices);
U->replaceUsesOfWith(GV, Addr);
}
// Remove old global.
NewGV->takeName(GV);
GV->eraseFromParent();
return true;
}
// This function replaces all global variables with new variables that have
// trailing redzones. It also creates a function that poisons
// redzones and inserts this function into llvm.global_ctors.
bool AddressSanitizer::insertGlobalRedzones(Module &M) {
SmallVector<GlobalVariable *, 16> GlobalsToChange;
for (Module::GlobalListType::iterator G = M.global_begin(),
E = M.global_end(); G != E; ++G) {
if (ShouldInstrumentGlobal(G))
GlobalsToChange.push_back(G);
}
size_t n = GlobalsToChange.size();
if (n == 0) return false;
// A global is described by a structure
// size_t beg;
// size_t size;
// size_t size_with_redzone;
// const char *name;
// size_t has_dynamic_init;
// We initialize an array of such structures and pass it to a run-time call.
StructType *GlobalStructTy = StructType::get(IntptrTy, IntptrTy,
IntptrTy, IntptrTy,
IntptrTy, NULL);
SmallVector<Constant *, 16> Initializers(n), DynamicInit;
IRBuilder<> IRB(CtorInsertBefore);
if (ClInitializers)
FindDynamicInitializers(M);
// The addresses of the first and last dynamically initialized globals in
// this TU. Used in initialization order checking.
Value *FirstDynamic = 0, *LastDynamic = 0;
for (size_t i = 0; i < n; i++) {
GlobalVariable *G = GlobalsToChange[i];
PointerType *PtrTy = cast<PointerType>(G->getType());
Type *Ty = PtrTy->getElementType();
uint64_t SizeInBytes = TD->getTypeAllocSize(Ty);
uint64_t RightRedzoneSize = RedzoneSize +
(RedzoneSize - (SizeInBytes % RedzoneSize));
Type *RightRedZoneTy = ArrayType::get(IRB.getInt8Ty(), RightRedzoneSize);
// Determine whether this global should be poisoned in initialization.
bool GlobalHasDynamicInitializer = HasDynamicInitializer(G);
// Don't check initialization order if this global is blacklisted.
GlobalHasDynamicInitializer &= !BL->isInInit(*G);
StructType *NewTy = StructType::get(Ty, RightRedZoneTy, NULL);
Constant *NewInitializer = ConstantStruct::get(
NewTy, G->getInitializer(),
Constant::getNullValue(RightRedZoneTy), NULL);
SmallString<2048> DescriptionOfGlobal = G->getName();
DescriptionOfGlobal += " (";
DescriptionOfGlobal += M.getModuleIdentifier();
DescriptionOfGlobal += ")";
GlobalVariable *Name = createPrivateGlobalForString(M, DescriptionOfGlobal);
// Create a new global variable with enough space for a redzone.
GlobalVariable *NewGlobal = new GlobalVariable(
M, NewTy, G->isConstant(), G->getLinkage(),
NewInitializer, "", G, G->getThreadLocalMode());
NewGlobal->copyAttributesFrom(G);
NewGlobal->setAlignment(RedzoneSize);
Value *Indices2[2];
Indices2[0] = IRB.getInt32(0);
Indices2[1] = IRB.getInt32(0);
G->replaceAllUsesWith(
ConstantExpr::getGetElementPtr(NewGlobal, Indices2, true));
NewGlobal->takeName(G);
G->eraseFromParent();
Initializers[i] = ConstantStruct::get(
GlobalStructTy,
ConstantExpr::getPointerCast(NewGlobal, IntptrTy),
ConstantInt::get(IntptrTy, SizeInBytes),
ConstantInt::get(IntptrTy, SizeInBytes + RightRedzoneSize),
ConstantExpr::getPointerCast(Name, IntptrTy),
ConstantInt::get(IntptrTy, GlobalHasDynamicInitializer),
NULL);
// Populate the first and last globals declared in this TU.
if (ClInitializers && GlobalHasDynamicInitializer) {
LastDynamic = ConstantExpr::getPointerCast(NewGlobal, IntptrTy);
if (FirstDynamic == 0)
FirstDynamic = LastDynamic;
}
DEBUG(dbgs() << "NEW GLOBAL:\n" << *NewGlobal);
}
ArrayType *ArrayOfGlobalStructTy = ArrayType::get(GlobalStructTy, n);
GlobalVariable *AllGlobals = new GlobalVariable(
M, ArrayOfGlobalStructTy, false, GlobalVariable::PrivateLinkage,
ConstantArray::get(ArrayOfGlobalStructTy, Initializers), "");
// Create calls for poisoning before initializers run and unpoisoning after.
if (ClInitializers && FirstDynamic && LastDynamic)
createInitializerPoisonCalls(M, FirstDynamic, LastDynamic);
Function *AsanRegisterGlobals = checkInterfaceFunction(M.getOrInsertFunction(
kAsanRegisterGlobalsName, IRB.getVoidTy(),
IntptrTy, IntptrTy, NULL));
AsanRegisterGlobals->setLinkage(Function::ExternalLinkage);
IRB.CreateCall2(AsanRegisterGlobals,
IRB.CreatePointerCast(AllGlobals, IntptrTy),
ConstantInt::get(IntptrTy, n));
// We also need to unregister globals at the end, e.g. when a shared library
// gets closed.
Function *AsanDtorFunction = Function::Create(
FunctionType::get(Type::getVoidTy(*C), false),
GlobalValue::InternalLinkage, kAsanModuleDtorName, &M);
BasicBlock *AsanDtorBB = BasicBlock::Create(*C, "", AsanDtorFunction);
IRBuilder<> IRB_Dtor(ReturnInst::Create(*C, AsanDtorBB));
Function *AsanUnregisterGlobals =
checkInterfaceFunction(M.getOrInsertFunction(
kAsanUnregisterGlobalsName,
IRB.getVoidTy(), IntptrTy, IntptrTy, NULL));
AsanUnregisterGlobals->setLinkage(Function::ExternalLinkage);
IRB_Dtor.CreateCall2(AsanUnregisterGlobals,
IRB.CreatePointerCast(AllGlobals, IntptrTy),
ConstantInt::get(IntptrTy, n));
appendToGlobalDtors(M, AsanDtorFunction, kAsanCtorAndCtorPriority);
DEBUG(dbgs() << M);
return true;
}
// This function replaces all global variables with new variables that have
// trailing redzones. It also creates a function that poisons
// redzones and inserts this function into llvm.global_ctors.
bool AddressSanitizer::insertGlobalRedzones(Module &M) {
SmallVector<GlobalVariable *, 16> GlobalsToChange;
for (Module::GlobalListType::iterator G = M.getGlobalList().begin(),
E = M.getGlobalList().end(); G != E; ++G) {
Type *Ty = cast<PointerType>(G->getType())->getElementType();
DEBUG(dbgs() << "GLOBAL: " << *G);
if (!Ty->isSized()) continue;
if (!G->hasInitializer()) continue;
// Touch only those globals that will not be defined in other modules.
// Don't handle ODR type linkages since other modules may be built w/o asan.
if (G->getLinkage() != GlobalVariable::ExternalLinkage &&
G->getLinkage() != GlobalVariable::PrivateLinkage &&
G->getLinkage() != GlobalVariable::InternalLinkage)
continue;
// Two problems with thread-locals:
// - The address of the main thread's copy can't be computed at link-time.
// - Need to poison all copies, not just the main thread's one.
if (G->isThreadLocal())
continue;
// For now, just ignore this Alloca if the alignment is large.
if (G->getAlignment() > RedzoneSize) continue;
// Ignore all the globals with the names starting with "\01L_OBJC_".
// Many of those are put into the .cstring section. The linker compresses
// that section by removing the spare \0s after the string terminator, so
// our redzones get broken.
if ((G->getName().find("\01L_OBJC_") == 0) ||
(G->getName().find("\01l_OBJC_") == 0)) {
DEBUG(dbgs() << "Ignoring \\01L_OBJC_* global: " << *G);
continue;
}
if (G->hasSection()) {
StringRef Section(G->getSection());
// Ignore the globals from the __OBJC section. The ObjC runtime assumes
// those conform to /usr/lib/objc/runtime.h, so we can't add redzones to
// them.
if ((Section.find("__OBJC,") == 0) ||
(Section.find("__DATA, __objc_") == 0)) {
DEBUG(dbgs() << "Ignoring ObjC runtime global: " << *G);
continue;
}
// See http://code.google.com/p/address-sanitizer/issues/detail?id=32
// Constant CFString instances are compiled in the following way:
// -- the string buffer is emitted into
// __TEXT,__cstring,cstring_literals
// -- the constant NSConstantString structure referencing that buffer
// is placed into __DATA,__cfstring
// Therefore there's no point in placing redzones into __DATA,__cfstring.
// Moreover, it causes the linker to crash on OS X 10.7
if (Section.find("__DATA,__cfstring") == 0) {
DEBUG(dbgs() << "Ignoring CFString: " << *G);
continue;
}
}
GlobalsToChange.push_back(G);
}
size_t n = GlobalsToChange.size();
if (n == 0) return false;
// A global is described by a structure
// size_t beg;
// size_t size;
// size_t size_with_redzone;
// const char *name;
// We initialize an array of such structures and pass it to a run-time call.
StructType *GlobalStructTy = StructType::get(IntptrTy, IntptrTy,
IntptrTy, IntptrTy, NULL);
SmallVector<Constant *, 16> Initializers(n);
IRBuilder<> IRB(CtorInsertBefore);
for (size_t i = 0; i < n; i++) {
GlobalVariable *G = GlobalsToChange[i];
PointerType *PtrTy = cast<PointerType>(G->getType());
Type *Ty = PtrTy->getElementType();
uint64_t SizeInBytes = TD->getTypeStoreSizeInBits(Ty) / 8;
uint64_t RightRedzoneSize = RedzoneSize +
(RedzoneSize - (SizeInBytes % RedzoneSize));
Type *RightRedZoneTy = ArrayType::get(IRB.getInt8Ty(), RightRedzoneSize);
StructType *NewTy = StructType::get(Ty, RightRedZoneTy, NULL);
Constant *NewInitializer = ConstantStruct::get(
NewTy, G->getInitializer(),
Constant::getNullValue(RightRedZoneTy), NULL);
SmallString<2048> DescriptionOfGlobal = G->getName();
DescriptionOfGlobal += " (";
DescriptionOfGlobal += M.getModuleIdentifier();
DescriptionOfGlobal += ")";
GlobalVariable *Name = createPrivateGlobalForString(M, DescriptionOfGlobal);
// Create a new global variable with enough space for a redzone.
GlobalVariable *NewGlobal = new GlobalVariable(
M, NewTy, G->isConstant(), G->getLinkage(),
NewInitializer, "", G, G->isThreadLocal());
NewGlobal->copyAttributesFrom(G);
NewGlobal->setAlignment(RedzoneSize);
Value *Indices2[2];
Indices2[0] = IRB.getInt32(0);
Indices2[1] = IRB.getInt32(0);
G->replaceAllUsesWith(
ConstantExpr::getGetElementPtr(NewGlobal, Indices2, true));
NewGlobal->takeName(G);
G->eraseFromParent();
Initializers[i] = ConstantStruct::get(
GlobalStructTy,
ConstantExpr::getPointerCast(NewGlobal, IntptrTy),
ConstantInt::get(IntptrTy, SizeInBytes),
ConstantInt::get(IntptrTy, SizeInBytes + RightRedzoneSize),
ConstantExpr::getPointerCast(Name, IntptrTy),
NULL);
DEBUG(dbgs() << "NEW GLOBAL:\n" << *NewGlobal);
}
ArrayType *ArrayOfGlobalStructTy = ArrayType::get(GlobalStructTy, n);
GlobalVariable *AllGlobals = new GlobalVariable(
M, ArrayOfGlobalStructTy, false, GlobalVariable::PrivateLinkage,
ConstantArray::get(ArrayOfGlobalStructTy, Initializers), "");
Function *AsanRegisterGlobals = cast<Function>(M.getOrInsertFunction(
kAsanRegisterGlobalsName, IRB.getVoidTy(), IntptrTy, IntptrTy, NULL));
AsanRegisterGlobals->setLinkage(Function::ExternalLinkage);
IRB.CreateCall2(AsanRegisterGlobals,
IRB.CreatePointerCast(AllGlobals, IntptrTy),
ConstantInt::get(IntptrTy, n));
// We also need to unregister globals at the end, e.g. when a shared library
// gets closed.
Function *AsanDtorFunction = Function::Create(
FunctionType::get(Type::getVoidTy(*C), false),
GlobalValue::InternalLinkage, kAsanModuleDtorName, &M);
BasicBlock *AsanDtorBB = BasicBlock::Create(*C, "", AsanDtorFunction);
IRBuilder<> IRB_Dtor(ReturnInst::Create(*C, AsanDtorBB));
Function *AsanUnregisterGlobals = cast<Function>(M.getOrInsertFunction(
kAsanUnregisterGlobalsName, IRB.getVoidTy(), IntptrTy, IntptrTy, NULL));
AsanUnregisterGlobals->setLinkage(Function::ExternalLinkage);
IRB_Dtor.CreateCall2(AsanUnregisterGlobals,
IRB.CreatePointerCast(AllGlobals, IntptrTy),
ConstantInt::get(IntptrTy, n));
appendToGlobalDtors(M, AsanDtorFunction, kAsanCtorAndCtorPriority);
DEBUG(dbgs() << M);
return true;
}
// make_decl_llvm - Create the DECL_RTL for a VAR_DECL or FUNCTION_DECL. DECL
// should have static storage duration. In other words, it should not be an
// automatic variable, including PARM_DECLs.
//
// There is, however, one exception: this function handles variables explicitly
// placed in a particular register by the user.
//
// This function corresponds to make_decl_rtl in varasm.c, and is implicitly
// called by DECL_LLVM if a decl doesn't have an LLVM set.
//
void make_decl_llvm(tree decl) {
#ifdef ENABLE_CHECKING
// Check that we are not being given an automatic variable.
// A weak alias has TREE_PUBLIC set but not the other bits.
if (TREE_CODE(decl) == PARM_DECL || TREE_CODE(decl) == RESULT_DECL
|| (TREE_CODE(decl) == VAR_DECL && !TREE_STATIC(decl) &&
!TREE_PUBLIC(decl) && !DECL_EXTERNAL(decl) && !DECL_REGISTER(decl)))
abort();
// And that we were not given a type or a label. */
else if (TREE_CODE(decl) == TYPE_DECL || TREE_CODE(decl) == LABEL_DECL)
abort ();
#endif
// For a duplicate declaration, we can be called twice on the
// same DECL node. Don't discard the LLVM already made.
if (DECL_LLVM_SET_P(decl)) return;
if (errorcount || sorrycount)
return; // Do not process broken code.
// Global register variable with asm name, e.g.:
// register unsigned long esp __asm__("ebp");
if (TREE_CODE(decl) != FUNCTION_DECL && DECL_REGISTER(decl)) {
// This just verifies that the variable is ok. The actual "load/store"
// code paths handle accesses to the variable.
ValidateRegisterVariable(decl);
return;
}
timevar_push(TV_LLVM_GLOBALS);
const char *Name = "";
if (DECL_NAME(decl))
if (tree AssemblerName = DECL_ASSEMBLER_NAME(decl))
Name = IDENTIFIER_POINTER(AssemblerName);
// Now handle ordinary static variables and functions (in memory).
// Also handle vars declared register invalidly.
if (Name[0] == 1) {
#ifdef REGISTER_PREFIX
if (strlen (REGISTER_PREFIX) != 0) {
int reg_number = decode_reg_name(Name);
if (reg_number >= 0 || reg_number == -3)
error("%Jregister name given for non-register variable %qD",
decl, decl);
}
#endif
}
// Specifying a section attribute on a variable forces it into a
// non-.bss section, and thus it cannot be common.
if (TREE_CODE(decl) == VAR_DECL && DECL_SECTION_NAME(decl) != NULL_TREE &&
DECL_INITIAL(decl) == NULL_TREE && DECL_COMMON(decl))
DECL_COMMON(decl) = 0;
// Variables can't be both common and weak.
if (TREE_CODE(decl) == VAR_DECL && DECL_WEAK(decl))
DECL_COMMON(decl) = 0;
// Okay, now we need to create an LLVM global variable or function for this
// object. Note that this is quite possibly a forward reference to the
// object, so its type may change later.
if (TREE_CODE(decl) == FUNCTION_DECL) {
assert(Name[0] && "Function with empty name!");
// If this function has already been created, reuse the decl. This happens
// when we have something like __builtin_memset and memset in the same file.
Function *FnEntry = TheModule->getFunction(Name);
if (FnEntry == 0) {
unsigned CC;
const FunctionType *Ty =
TheTypeConverter->ConvertFunctionType(TREE_TYPE(decl), decl, NULL, CC);
FnEntry = new Function(Ty, Function::ExternalLinkage, Name, TheModule);
FnEntry->setCallingConv(CC);
// Check for external weak linkage
if (DECL_EXTERNAL(decl) && DECL_WEAK(decl))
FnEntry->setLinkage(Function::ExternalWeakLinkage);
#ifdef TARGET_ADJUST_LLVM_LINKAGE
TARGET_ADJUST_LLVM_LINKAGE(FnEntry,decl);
#endif /* TARGET_ADJUST_LLVM_LINKAGE */
// Handle visibility style
if (TREE_PUBLIC(decl)) {
if (DECL_VISIBILITY(decl) == VISIBILITY_HIDDEN)
FnEntry->setVisibility(GlobalValue::HiddenVisibility);
else if (DECL_VISIBILITY(decl) == VISIBILITY_PROTECTED)
FnEntry->setVisibility(GlobalValue::ProtectedVisibility);
}
assert(FnEntry->getName() == Name &&"Preexisting fn with the same name!");
}
SET_DECL_LLVM(decl, FnEntry);
} else {
assert((TREE_CODE(decl) == VAR_DECL ||
TREE_CODE(decl) == CONST_DECL) && "Not a function or var decl?");
const Type *Ty = ConvertType(TREE_TYPE(decl));
GlobalVariable *GV ;
// If we have "extern void foo", make the global have type {} instead of
// type void.
if (Ty == Type::VoidTy)
Ty = StructType::get(std::vector<const Type*>(), false);
if (Name[0] == 0) { // Global has no name.
GV = new GlobalVariable(Ty, false, GlobalValue::ExternalLinkage, 0,
"", TheModule);
// Check for external weak linkage
if (DECL_EXTERNAL(decl) && DECL_WEAK(decl))
GV->setLinkage(GlobalValue::ExternalWeakLinkage);
#ifdef TARGET_ADJUST_LLVM_LINKAGE
TARGET_ADJUST_LLVM_LINKAGE(GV,decl);
#endif /* TARGET_ADJUST_LLVM_LINKAGE */
// Handle visibility style
if (TREE_PUBLIC(decl)) {
if (DECL_VISIBILITY(decl) == VISIBILITY_HIDDEN)
GV->setVisibility(GlobalValue::HiddenVisibility);
else if (DECL_VISIBILITY(decl) == VISIBILITY_PROTECTED)
GV->setVisibility(GlobalValue::ProtectedVisibility);
}
} else {
// If the global has a name, prevent multiple vars with the same name from
// being created.
GlobalVariable *GVE = TheModule->getGlobalVariable(Name);
if (GVE == 0) {
GV = new GlobalVariable(Ty, false, GlobalValue::ExternalLinkage,0,
Name, TheModule);
// Check for external weak linkage
if (DECL_EXTERNAL(decl) && DECL_WEAK(decl))
GV->setLinkage(GlobalValue::ExternalWeakLinkage);
#ifdef TARGET_ADJUST_LLVM_LINKAGE
TARGET_ADJUST_LLVM_LINKAGE(GV,decl);
#endif /* TARGET_ADJUST_LLVM_LINKAGE */
// Handle visibility style
if (TREE_PUBLIC(decl)) {
if (DECL_VISIBILITY(decl) == VISIBILITY_HIDDEN)
GV->setVisibility(GlobalValue::HiddenVisibility);
else if (DECL_VISIBILITY(decl) == VISIBILITY_PROTECTED)
GV->setVisibility(GlobalValue::ProtectedVisibility);
}
// If GV got renamed, then there is already an object with this name in
// the symbol table. If this happens, the old one must be a forward
// decl, just replace it with a cast of the new one.
if (GV->getName() != Name) {
Function *F = TheModule->getFunction(Name);
assert(F && F->isDeclaration() && "A function turned into a global?");
// Replace any uses of "F" with uses of GV.
Value *FInNewType = ConstantExpr::getBitCast(GV, F->getType());
F->replaceAllUsesWith(FInNewType);
// Update the decl that points to F.
changeLLVMValue(F, FInNewType);
// Now we can give GV the proper name.
GV->takeName(F);
// F is now dead, nuke it.
F->eraseFromParent();
}
} else {
GV = GVE; // Global already created, reuse it.
}
}
if ((TREE_READONLY(decl) && !TREE_SIDE_EFFECTS(decl)) ||
TREE_CODE(decl) == CONST_DECL) {
if (DECL_EXTERNAL(decl)) {
// Mark external globals constant even though they could be marked
// non-constant in the defining translation unit. The definition of the
// global determines whether the global is ultimately constant or not,
// marking this constant will allow us to do some extra (legal)
// optimizations that we would otherwise not be able to do. (In C++,
// any global that is 'C++ const' may not be readonly: it could have a
// dynamic initializer.
//
GV->setConstant(true);
} else {
// Mark readonly globals with constant initializers constant.
if (DECL_INITIAL(decl) != error_mark_node && // uninitialized?
DECL_INITIAL(decl) &&
(TREE_CONSTANT(DECL_INITIAL(decl)) ||
TREE_CODE(DECL_INITIAL(decl)) == STRING_CST))
GV->setConstant(true);
}
}
// Set thread local (TLS)
if (TREE_CODE(decl) == VAR_DECL && DECL_THREAD_LOCAL(decl))
GV->setThreadLocal(true);
SET_DECL_LLVM(decl, GV);
}
timevar_pop(TV_LLVM_GLOBALS);
}