std::unique_ptr<StructInfo> StructInfo::getFromGlobalPointer(Module *module, llvm::StringRef name)
{
GlobalVariable *var = module->getGlobalVariable(name, false);
if (!var || !var->getType() || !var->getType()->isPointerTy()) {
assert(false);
llvm::errs() << "StructInfo: Cannot get global variable " << name << ", or it is not a pointer." << '\n';
return nullptr;
}
PointerType *varDeref = dyn_cast<PointerType>(var->getType()->getElementType());
if (!varDeref || !varDeref->getElementType())
{
assert(false);
llvm::errs() << "StructInfo: Pointer not valid." << '\n';
return nullptr;
}
StructType *structType = dyn_cast<StructType>(varDeref->getElementType());
if (!structType) {
assert(false);
llvm::errs() << "StructInfo: Cannot get struct type." << '\n';
return nullptr;
}
NamedMDNode *mdCuNodes = module->getNamedMetadata("llvm.dbg.cu");
if (!mdCuNodes) {
assert(false);
llvm::errs() << "StructInfo: Cannot find metadata." << '\n';
return nullptr;
}
std::shared_ptr<DITypeIdentifierMap> typeIdentifierMap(new DITypeIdentifierMap(generateDITypeIdentifierMap(mdCuNodes)));
DICompositeType *diStructType = nullptr;
for ( unsigned i = 0; i < mdCuNodes->getNumOperands() && !diStructType; ++i )
{
DICompileUnit diCu(mdCuNodes->getOperand(i));
for ( unsigned j = 0; j < diCu.getGlobalVariables().getNumElements(); ++j )
{
DIGlobalVariable diGlobalVar(diCu.getGlobalVariables().getElement(j));
if (diGlobalVar.getName() != name) {
continue;
}
//Go through pointers until we reach a structure
DIType diStructType(diGlobalVar.getType());
while (diStructType.isDerivedType() && !diStructType.isCompositeType()) {
diStructType = std::unique_ptr<DIDerivedType>(new DIDerivedType(diStructType))->getTypeDerivedFrom().resolve(*typeIdentifierMap);
}
if (!diStructType.isCompositeType()) {
llvm::errs() << "StructInfo: Global variable " << name << " does not point to a composite type: " << diStructType.getName() << '\n';
assert(false);
return nullptr;
}
return std::unique_ptr<StructInfo>(new StructInfo(
module,
structType,
new DICompositeType(diStructType),
typeIdentifierMap));
}
}
assert(false);
llvm::errs() << "StructInfo: Did not find global variable " << name << " in debug information." << '\n';
return nullptr;
}
/// constructTypeDIE - Construct type DIE from DICompositeType.
void CompileUnit::constructTypeDIE(DIE &Buffer, DICompositeType CTy) {
// Get core information.
StringRef Name = CTy.getName();
uint64_t Size = CTy.getSizeInBits() >> 3;
unsigned Tag = CTy.getTag();
Buffer.setTag(Tag);
switch (Tag) {
case dwarf::DW_TAG_vector_type:
case dwarf::DW_TAG_array_type:
constructArrayTypeDIE(Buffer, &CTy);
break;
case dwarf::DW_TAG_enumeration_type: {
DIArray Elements = CTy.getTypeArray();
// Add enumerators to enumeration type.
for (unsigned i = 0, N = Elements.getNumElements(); i < N; ++i) {
DIE *ElemDie = NULL;
DIDescriptor Enum(Elements.getElement(i));
if (Enum.isEnumerator()) {
ElemDie = constructEnumTypeDIE(DIEnumerator(Enum));
Buffer.addChild(ElemDie);
}
}
}
break;
case dwarf::DW_TAG_subroutine_type: {
// Add return type.
DIArray Elements = CTy.getTypeArray();
DIDescriptor RTy = Elements.getElement(0);
addType(&Buffer, DIType(RTy));
bool isPrototyped = true;
// Add arguments.
for (unsigned i = 1, N = Elements.getNumElements(); i < N; ++i) {
DIDescriptor Ty = Elements.getElement(i);
if (Ty.isUnspecifiedParameter()) {
DIE *Arg = new DIE(dwarf::DW_TAG_unspecified_parameters);
Buffer.addChild(Arg);
isPrototyped = false;
} else {
DIE *Arg = new DIE(dwarf::DW_TAG_formal_parameter);
addType(Arg, DIType(Ty));
Buffer.addChild(Arg);
}
}
// Add prototype flag.
if (isPrototyped)
addUInt(&Buffer, dwarf::DW_AT_prototyped, dwarf::DW_FORM_flag, 1);
}
break;
case dwarf::DW_TAG_structure_type:
case dwarf::DW_TAG_union_type:
case dwarf::DW_TAG_class_type: {
// Add elements to structure type.
DIArray Elements = CTy.getTypeArray();
// A forward struct declared type may not have elements available.
unsigned N = Elements.getNumElements();
if (N == 0)
break;
// Add elements to structure type.
for (unsigned i = 0; i < N; ++i) {
DIDescriptor Element = Elements.getElement(i);
DIE *ElemDie = NULL;
if (Element.isSubprogram()) {
DISubprogram SP(Element);
ElemDie = DD->createSubprogramDIE(DISubprogram(Element));
if (SP.isProtected())
addUInt(ElemDie, dwarf::DW_AT_accessibility, dwarf::DW_FORM_flag,
dwarf::DW_ACCESS_protected);
else if (SP.isPrivate())
addUInt(ElemDie, dwarf::DW_AT_accessibility, dwarf::DW_FORM_flag,
dwarf::DW_ACCESS_private);
else
addUInt(ElemDie, dwarf::DW_AT_accessibility, dwarf::DW_FORM_flag,
dwarf::DW_ACCESS_public);
if (SP.isExplicit())
addUInt(ElemDie, dwarf::DW_AT_explicit, dwarf::DW_FORM_flag, 1);
}
else if (Element.isVariable()) {
DIVariable DV(Element);
ElemDie = new DIE(dwarf::DW_TAG_variable);
addString(ElemDie, dwarf::DW_AT_name, dwarf::DW_FORM_string,
DV.getName());
addType(ElemDie, DV.getType());
addUInt(ElemDie, dwarf::DW_AT_declaration, dwarf::DW_FORM_flag, 1);
addUInt(ElemDie, dwarf::DW_AT_external, dwarf::DW_FORM_flag, 1);
addSourceLine(ElemDie, DV);
} else if (Element.isDerivedType())
ElemDie = createMemberDIE(DIDerivedType(Element));
else
continue;
Buffer.addChild(ElemDie);
}
if (CTy.isAppleBlockExtension())
addUInt(&Buffer, dwarf::DW_AT_APPLE_block, dwarf::DW_FORM_flag, 1);
unsigned RLang = CTy.getRunTimeLang();
if (RLang)
addUInt(&Buffer, dwarf::DW_AT_APPLE_runtime_class,
dwarf::DW_FORM_data1, RLang);
DICompositeType ContainingType = CTy.getContainingType();
if (DIDescriptor(ContainingType).isCompositeType())
addDIEEntry(&Buffer, dwarf::DW_AT_containing_type, dwarf::DW_FORM_ref4,
getOrCreateTypeDIE(DIType(ContainingType)));
else {
DIDescriptor Context = CTy.getContext();
addToContextOwner(&Buffer, Context);
}
if (CTy.isObjcClassComplete())
addUInt(&Buffer, dwarf::DW_AT_APPLE_objc_complete_type,
dwarf::DW_FORM_flag, 1);
if (Tag == dwarf::DW_TAG_class_type)
addTemplateParams(Buffer, CTy.getTemplateParams());
break;
}
default:
break;
}
// Add name if not anonymous or intermediate type.
if (!Name.empty())
addString(&Buffer, dwarf::DW_AT_name, dwarf::DW_FORM_string, Name);
if (Tag == dwarf::DW_TAG_enumeration_type || Tag == dwarf::DW_TAG_class_type
|| Tag == dwarf::DW_TAG_structure_type || Tag == dwarf::DW_TAG_union_type)
{
// Add size if non-zero (derived types might be zero-sized.)
if (Size)
addUInt(&Buffer, dwarf::DW_AT_byte_size, 0, Size);
else {
// Add zero size if it is not a forward declaration.
if (CTy.isForwardDecl())
addUInt(&Buffer, dwarf::DW_AT_declaration, dwarf::DW_FORM_flag, 1);
else
addUInt(&Buffer, dwarf::DW_AT_byte_size, 0, 0);
}
// Add source line info if available.
if (!CTy.isForwardDecl())
addSourceLine(&Buffer, CTy);
}
}