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/*
* Copyright (C) 2016 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef ART_COMPILER_DEBUG_ELF_DEBUG_INFO_WRITER_H_
#define ART_COMPILER_DEBUG_ELF_DEBUG_INFO_WRITER_H_
#include <map>
#include <unordered_set>
#include <vector>
#include "art_field-inl.h"
#include "debug/dwarf/debug_abbrev_writer.h"
#include "debug/dwarf/debug_info_entry_writer.h"
#include "debug/elf_compilation_unit.h"
#include "debug/elf_debug_loc_writer.h"
#include "debug/method_debug_info.h"
#include "dex/code_item_accessors-inl.h"
#include "dex/dex_file-inl.h"
#include "dex/dex_file.h"
#include "heap_poisoning.h"
#include "linear_alloc.h"
#include "linker/elf_builder.h"
#include "mirror/array.h"
#include "mirror/class-inl.h"
#include "mirror/class.h"
#include "oat_file.h"
namespace art {
namespace debug {
typedef std::vector<DexFile::LocalInfo> LocalInfos;
static void LocalInfoCallback(void* ctx, const DexFile::LocalInfo& entry) {
static_cast<LocalInfos*>(ctx)->push_back(entry);
}
static std::vector<const char*> GetParamNames(const MethodDebugInfo* mi) {
std::vector<const char*> names;
CodeItemDebugInfoAccessor accessor(*mi->dex_file, mi->code_item, mi->dex_method_index);
if (accessor.HasCodeItem()) {
DCHECK(mi->dex_file != nullptr);
const uint8_t* stream = mi->dex_file->GetDebugInfoStream(accessor.DebugInfoOffset());
if (stream != nullptr) {
DecodeUnsignedLeb128(&stream); // line.
uint32_t parameters_size = DecodeUnsignedLeb128(&stream);
for (uint32_t i = 0; i < parameters_size; ++i) {
uint32_t id = DecodeUnsignedLeb128P1(&stream);
names.push_back(mi->dex_file->StringDataByIdx(dex::StringIndex(id)));
}
}
}
return names;
}
// Helper class to write .debug_info and its supporting sections.
template<typename ElfTypes>
class ElfDebugInfoWriter {
using Elf_Addr = typename ElfTypes::Addr;
public:
explicit ElfDebugInfoWriter(linker::ElfBuilder<ElfTypes>* builder)
: builder_(builder),
debug_abbrev_(&debug_abbrev_buffer_) {
}
void Start() {
builder_->GetDebugInfo()->Start();
}
void End(bool write_oat_patches) {
builder_->GetDebugInfo()->End();
if (write_oat_patches) {
builder_->WritePatches(".debug_info.oat_patches",
ArrayRef<const uintptr_t>(debug_info_patches_));
}
builder_->WriteSection(".debug_abbrev", &debug_abbrev_buffer_);
if (!debug_loc_.empty()) {
builder_->WriteSection(".debug_loc", &debug_loc_);
}
if (!debug_ranges_.empty()) {
builder_->WriteSection(".debug_ranges", &debug_ranges_);
}
}
private:
linker::ElfBuilder<ElfTypes>* builder_;
std::vector<uintptr_t> debug_info_patches_;
std::vector<uint8_t> debug_abbrev_buffer_;
dwarf::DebugAbbrevWriter<> debug_abbrev_;
std::vector<uint8_t> debug_loc_;
std::vector<uint8_t> debug_ranges_;
std::unordered_set<const char*> defined_dex_classes_; // For CHECKs only.
template<typename ElfTypes2>
friend class ElfCompilationUnitWriter;
};
// Helper class to write one compilation unit.
// It holds helper methods and temporary state.
template<typename ElfTypes>
class ElfCompilationUnitWriter {
using Elf_Addr = typename ElfTypes::Addr;
public:
explicit ElfCompilationUnitWriter(ElfDebugInfoWriter<ElfTypes>* owner)
: owner_(owner),
info_(Is64BitInstructionSet(owner_->builder_->GetIsa()), &owner->debug_abbrev_) {
}
void Write(const ElfCompilationUnit& compilation_unit) {
CHECK(!compilation_unit.methods.empty());
const Elf_Addr base_address = compilation_unit.is_code_address_text_relative
? owner_->builder_->GetText()->GetAddress()
: 0;
const bool is64bit = Is64BitInstructionSet(owner_->builder_->GetIsa());
using namespace dwarf; // NOLINT. For easy access to DWARF constants.
info_.StartTag(DW_TAG_compile_unit);
info_.WriteString(DW_AT_producer, "Android dex2oat");
info_.WriteData1(DW_AT_language, DW_LANG_Java);
info_.WriteString(DW_AT_comp_dir, "$JAVA_SRC_ROOT");
// The low_pc acts as base address for several other addresses/ranges.
info_.WriteAddr(DW_AT_low_pc, base_address + compilation_unit.code_address);
info_.WriteSecOffset(DW_AT_stmt_list, compilation_unit.debug_line_offset);
// Write .debug_ranges entries covering code ranges of the whole compilation unit.
dwarf::Writer<> debug_ranges(&owner_->debug_ranges_);
info_.WriteSecOffset(DW_AT_ranges, owner_->debug_ranges_.size());
for (auto mi : compilation_unit.methods) {
uint64_t low_pc = mi->code_address - compilation_unit.code_address;
uint64_t high_pc = low_pc + mi->code_size;
if (is64bit) {
debug_ranges.PushUint64(low_pc);
debug_ranges.PushUint64(high_pc);
} else {
debug_ranges.PushUint32(low_pc);
debug_ranges.PushUint32(high_pc);
}
}
if (is64bit) {
debug_ranges.PushUint64(0); // End of list.
debug_ranges.PushUint64(0);
} else {
debug_ranges.PushUint32(0); // End of list.
debug_ranges.PushUint32(0);
}
const char* last_dex_class_desc = nullptr;
for (auto mi : compilation_unit.methods) {
DCHECK(mi->dex_file != nullptr);
const DexFile* dex = mi->dex_file;
CodeItemDebugInfoAccessor accessor(*dex, mi->code_item, mi->dex_method_index);
const DexFile::MethodId& dex_method = dex->GetMethodId(mi->dex_method_index);
const DexFile::ProtoId& dex_proto = dex->GetMethodPrototype(dex_method);
const DexFile::TypeList* dex_params = dex->GetProtoParameters(dex_proto);
const char* dex_class_desc = dex->GetMethodDeclaringClassDescriptor(dex_method);
const bool is_static = (mi->access_flags & kAccStatic) != 0;
// Enclose the method in correct class definition.
if (last_dex_class_desc != dex_class_desc) {
if (last_dex_class_desc != nullptr) {
EndClassTag();
}
// Write reference tag for the class we are about to declare.
size_t reference_tag_offset = info_.StartTag(DW_TAG_reference_type);
type_cache_.emplace(std::string(dex_class_desc), reference_tag_offset);
size_t type_attrib_offset = info_.size();
info_.WriteRef4(DW_AT_type, 0);
info_.EndTag();
// Declare the class that owns this method.
size_t class_offset = StartClassTag(dex_class_desc);
info_.UpdateUint32(type_attrib_offset, class_offset);
info_.WriteFlagPresent(DW_AT_declaration);
// Check that each class is defined only once.
bool unique = owner_->defined_dex_classes_.insert(dex_class_desc).second;
CHECK(unique) << "Redefinition of " << dex_class_desc;
last_dex_class_desc = dex_class_desc;
}
int start_depth = info_.Depth();
info_.StartTag(DW_TAG_subprogram);
WriteName(dex->GetMethodName(dex_method));
info_.WriteAddr(DW_AT_low_pc, base_address + mi->code_address);
info_.WriteUdata(DW_AT_high_pc, mi->code_size);
std::vector<uint8_t> expr_buffer;
Expression expr(&expr_buffer);
expr.WriteOpCallFrameCfa();
info_.WriteExprLoc(DW_AT_frame_base, expr);
WriteLazyType(dex->GetReturnTypeDescriptor(dex_proto));
// Decode dex register locations for all stack maps.
// It might be expensive, so do it just once and reuse the result.
std::vector<DexRegisterMap> dex_reg_maps;
if (accessor.HasCodeItem() && mi->code_info != nullptr) {
const CodeInfo code_info(mi->code_info);
CodeInfoEncoding encoding = code_info.ExtractEncoding();
for (size_t s = 0; s < code_info.GetNumberOfStackMaps(encoding); ++s) {
const StackMap& stack_map = code_info.GetStackMapAt(s, encoding);
dex_reg_maps.push_back(code_info.GetDexRegisterMapOf(
stack_map, encoding, accessor.RegistersSize()));
}
}
// Write parameters. DecodeDebugLocalInfo returns them as well, but it does not
// guarantee order or uniqueness so it is safer to iterate over them manually.
// DecodeDebugLocalInfo might not also be available if there is no debug info.
std::vector<const char*> param_names = GetParamNames(mi);
uint32_t arg_reg = 0;
if (!is_static) {
info_.StartTag(DW_TAG_formal_parameter);
WriteName("this");
info_.WriteFlagPresent(DW_AT_artificial);
WriteLazyType(dex_class_desc);
if (accessor.HasCodeItem()) {
// Write the stack location of the parameter.
const uint32_t vreg = accessor.RegistersSize() - accessor.InsSize() + arg_reg;
const bool is64bitValue = false;
WriteRegLocation(mi, dex_reg_maps, vreg, is64bitValue, compilation_unit.code_address);
}
arg_reg++;
info_.EndTag();
}
if (dex_params != nullptr) {
for (uint32_t i = 0; i < dex_params->Size(); ++i) {
info_.StartTag(DW_TAG_formal_parameter);
// Parameter names may not be always available.
if (i < param_names.size()) {
WriteName(param_names[i]);
}
// Write the type.
const char* type_desc = dex->StringByTypeIdx(dex_params->GetTypeItem(i).type_idx_);
WriteLazyType(type_desc);
const bool is64bitValue = type_desc[0] == 'D' || type_desc[0] == 'J';
if (accessor.HasCodeItem()) {
// Write the stack location of the parameter.
const uint32_t vreg = accessor.RegistersSize() - accessor.InsSize() + arg_reg;
WriteRegLocation(mi, dex_reg_maps, vreg, is64bitValue, compilation_unit.code_address);
}
arg_reg += is64bitValue ? 2 : 1;
info_.EndTag();
}
if (accessor.HasCodeItem()) {
DCHECK_EQ(arg_reg, accessor.InsSize());
}
}
// Write local variables.
LocalInfos local_infos;
if (accessor.DecodeDebugLocalInfo(is_static,
mi->dex_method_index,
LocalInfoCallback,
&local_infos)) {
for (const DexFile::LocalInfo& var : local_infos) {
if (var.reg_ < accessor.RegistersSize() - accessor.InsSize()) {
info_.StartTag(DW_TAG_variable);
WriteName(var.name_);
WriteLazyType(var.descriptor_);
bool is64bitValue = var.descriptor_[0] == 'D' || var.descriptor_[0] == 'J';
WriteRegLocation(mi,
dex_reg_maps,
var.reg_,
is64bitValue,
compilation_unit.code_address,
var.start_address_,
var.end_address_);
info_.EndTag();
}
}
}
info_.EndTag();
CHECK_EQ(info_.Depth(), start_depth); // Balanced start/end.
}
if (last_dex_class_desc != nullptr) {
EndClassTag();
}
FinishLazyTypes();
CloseNamespacesAboveDepth(0);
info_.EndTag(); // DW_TAG_compile_unit
CHECK_EQ(info_.Depth(), 0);
std::vector<uint8_t> buffer;
buffer.reserve(info_.data()->size() + KB);
const size_t offset = owner_->builder_->GetDebugInfo()->GetPosition();
// All compilation units share single table which is at the start of .debug_abbrev.
const size_t debug_abbrev_offset = 0;
WriteDebugInfoCU(debug_abbrev_offset, info_, offset, &buffer, &owner_->debug_info_patches_);
owner_->builder_->GetDebugInfo()->WriteFully(buffer.data(), buffer.size());
}
void Write(const ArrayRef<mirror::Class*>& types) REQUIRES_SHARED(Locks::mutator_lock_) {
using namespace dwarf; // NOLINT. For easy access to DWARF constants.
info_.StartTag(DW_TAG_compile_unit);
info_.WriteString(DW_AT_producer, "Android dex2oat");
info_.WriteData1(DW_AT_language, DW_LANG_Java);
// Base class references to be patched at the end.
std::map<size_t, mirror::Class*> base_class_references;
// Already written declarations or definitions.
std::map<mirror::Class*, size_t> class_declarations;
std::vector<uint8_t> expr_buffer;
for (mirror::Class* type : types) {
if (type->IsPrimitive()) {
// For primitive types the definition and the declaration is the same.
if (type->GetPrimitiveType() != Primitive::kPrimVoid) {
WriteTypeDeclaration(type->GetDescriptor(nullptr));
}
} else if (type->IsArrayClass()) {
mirror::Class* element_type = type->GetComponentType();
uint32_t component_size = type->GetComponentSize();
uint32_t data_offset = mirror::Array::DataOffset(component_size).Uint32Value();
uint32_t length_offset = mirror::Array::LengthOffset().Uint32Value();
CloseNamespacesAboveDepth(0); // Declare in root namespace.
info_.StartTag(DW_TAG_array_type);
std::string descriptor_string;
WriteLazyType(element_type->GetDescriptor(&descriptor_string));
WriteLinkageName(type);
info_.WriteUdata(DW_AT_data_member_location, data_offset);
info_.StartTag(DW_TAG_subrange_type);
Expression count_expr(&expr_buffer);
count_expr.WriteOpPushObjectAddress();
count_expr.WriteOpPlusUconst(length_offset);
count_expr.WriteOpDerefSize(4); // Array length is always 32-bit wide.
info_.WriteExprLoc(DW_AT_count, count_expr);
info_.EndTag(); // DW_TAG_subrange_type.
info_.EndTag(); // DW_TAG_array_type.
} else if (type->IsInterface()) {
// Skip. Variables cannot have an interface as a dynamic type.
// We do not expose the interface information to the debugger in any way.
} else {
std::string descriptor_string;
const char* desc = type->GetDescriptor(&descriptor_string);
size_t class_offset = StartClassTag(desc);
class_declarations.emplace(type, class_offset);
if (!type->IsVariableSize()) {
info_.WriteUdata(DW_AT_byte_size, type->GetObjectSize());
}
WriteLinkageName(type);
if (type->IsObjectClass()) {
// Generate artificial member which is used to get the dynamic type of variable.
// The run-time value of this field will correspond to linkage name of some type.
// We need to do it only once in j.l.Object since all other types inherit it.
info_.StartTag(DW_TAG_member);
WriteName(".dynamic_type");
WriteLazyType(sizeof(uintptr_t) == 8 ? "J" : "I");
info_.WriteFlagPresent(DW_AT_artificial);
// Create DWARF expression to get the value of the methods_ field.
Expression expr(&expr_buffer);
// The address of the object has been implicitly pushed on the stack.
// Dereference the klass_ field of Object (32-bit; possibly poisoned).
DCHECK_EQ(type->ClassOffset().Uint32Value(), 0u);
DCHECK_EQ(sizeof(mirror::HeapReference<mirror::Class>), 4u);
expr.WriteOpDerefSize(4);
if (kPoisonHeapReferences) {
expr.WriteOpNeg();
// DWARF stack is pointer sized. Ensure that the high bits are clear.
expr.WriteOpConstu(0xFFFFFFFF);
expr.WriteOpAnd();
}
// Add offset to the methods_ field.
expr.WriteOpPlusUconst(mirror::Class::MethodsOffset().Uint32Value());
// Top of stack holds the location of the field now.
info_.WriteExprLoc(DW_AT_data_member_location, expr);
info_.EndTag(); // DW_TAG_member.
}
// Base class.
mirror::Class* base_class = type->GetSuperClass();
if (base_class != nullptr) {
info_.StartTag(DW_TAG_inheritance);
base_class_references.emplace(info_.size(), base_class);
info_.WriteRef4(DW_AT_type, 0);
info_.WriteUdata(DW_AT_data_member_location, 0);
info_.WriteSdata(DW_AT_accessibility, DW_ACCESS_public);
info_.EndTag(); // DW_TAG_inheritance.
}
// Member variables.
for (uint32_t i = 0, count = type->NumInstanceFields(); i < count; ++i) {
ArtField* field = type->GetInstanceField(i);
info_.StartTag(DW_TAG_member);
WriteName(field->GetName());
WriteLazyType(field->GetTypeDescriptor());
info_.WriteUdata(DW_AT_data_member_location, field->GetOffset().Uint32Value());
uint32_t access_flags = field->GetAccessFlags();
if (access_flags & kAccPublic) {
info_.WriteSdata(DW_AT_accessibility, DW_ACCESS_public);
} else if (access_flags & kAccProtected) {
info_.WriteSdata(DW_AT_accessibility, DW_ACCESS_protected);
} else if (access_flags & kAccPrivate) {
info_.WriteSdata(DW_AT_accessibility, DW_ACCESS_private);
}
info_.EndTag(); // DW_TAG_member.
}
if (type->IsStringClass()) {
// Emit debug info about an artifical class member for java.lang.String which represents
// the first element of the data stored in a string instance. Consumers of the debug
// info will be able to read the content of java.lang.String based on the count (real
// field) and based on the location of this data member.
info_.StartTag(DW_TAG_member);
WriteName("value");
// We don't support fields with C like array types so we just say its type is java char.
WriteLazyType("C"); // char.
info_.WriteUdata(DW_AT_data_member_location,
mirror::String::ValueOffset().Uint32Value());
info_.WriteSdata(DW_AT_accessibility, DW_ACCESS_private);
info_.EndTag(); // DW_TAG_member.
}
EndClassTag();
}
}
// Write base class declarations.
for (const auto& base_class_reference : base_class_references) {
size_t reference_offset = base_class_reference.first;
mirror::Class* base_class = base_class_reference.second;
const auto it = class_declarations.find(base_class);
if (it != class_declarations.end()) {
info_.UpdateUint32(reference_offset, it->second);
} else {
// Declare base class. We can not use the standard WriteLazyType
// since we want to avoid the DW_TAG_reference_tag wrapping.
std::string tmp_storage;
const char* base_class_desc = base_class->GetDescriptor(&tmp_storage);
size_t base_class_declaration_offset = StartClassTag(base_class_desc);
info_.WriteFlagPresent(DW_AT_declaration);
WriteLinkageName(base_class);
EndClassTag();
class_declarations.emplace(base_class, base_class_declaration_offset);
info_.UpdateUint32(reference_offset, base_class_declaration_offset);
}
}
FinishLazyTypes();
CloseNamespacesAboveDepth(0);
info_.EndTag(); // DW_TAG_compile_unit.
CHECK_EQ(info_.Depth(), 0);
std::vector<uint8_t> buffer;
buffer.reserve(info_.data()->size() + KB);
const size_t offset = owner_->builder_->GetDebugInfo()->GetPosition();
// All compilation units share single table which is at the start of .debug_abbrev.
const size_t debug_abbrev_offset = 0;
WriteDebugInfoCU(debug_abbrev_offset, info_, offset, &buffer, &owner_->debug_info_patches_);
owner_->builder_->GetDebugInfo()->WriteFully(buffer.data(), buffer.size());
}
// Write table into .debug_loc which describes location of dex register.
// The dex register might be valid only at some points and it might
// move between machine registers and stack.
void WriteRegLocation(const MethodDebugInfo* method_info,
const std::vector<DexRegisterMap>& dex_register_maps,
uint16_t vreg,
bool is64bitValue,
uint64_t compilation_unit_code_address,
uint32_t dex_pc_low = 0,
uint32_t dex_pc_high = 0xFFFFFFFF) {
WriteDebugLocEntry(method_info,
dex_register_maps,
vreg,
is64bitValue,
compilation_unit_code_address,
dex_pc_low,
dex_pc_high,
owner_->builder_->GetIsa(),
&info_,
&owner_->debug_loc_,
&owner_->debug_ranges_);
}
// Linkage name uniquely identifies type.
// It is used to determine the dynamic type of objects.
// We use the methods_ field of class since it is unique and it is not moved by the GC.
void WriteLinkageName(mirror::Class* type) REQUIRES_SHARED(Locks::mutator_lock_) {
auto* methods_ptr = type->GetMethodsPtr();
if (methods_ptr == nullptr) {
// Some types might have no methods. Allocate empty array instead.
LinearAlloc* allocator = Runtime::Current()->GetLinearAlloc();
void* storage = allocator->Alloc(Thread::Current(), sizeof(LengthPrefixedArray<ArtMethod>));
methods_ptr = new (storage) LengthPrefixedArray<ArtMethod>(0);
type->SetMethodsPtr(methods_ptr, 0, 0);
DCHECK(type->GetMethodsPtr() != nullptr);
}
char name[32];
snprintf(name, sizeof(name), "0x%" PRIXPTR, reinterpret_cast<uintptr_t>(methods_ptr));
info_.WriteString(dwarf::DW_AT_linkage_name, name);
}
// Some types are difficult to define as we go since they need
// to be enclosed in the right set of namespaces. Therefore we
// just define all types lazily at the end of compilation unit.
void WriteLazyType(const char* type_descriptor) {
if (type_descriptor != nullptr && type_descriptor[0] != 'V') {
lazy_types_.emplace(std::string(type_descriptor), info_.size());
info_.WriteRef4(dwarf::DW_AT_type, 0);
}
}
void FinishLazyTypes() {
for (const auto& lazy_type : lazy_types_) {
info_.UpdateUint32(lazy_type.second, WriteTypeDeclaration(lazy_type.first));
}
lazy_types_.clear();
}
private:
void WriteName(const char* name) {
if (name != nullptr) {
info_.WriteString(dwarf::DW_AT_name, name);
}
}
// Convert dex type descriptor to DWARF.
// Returns offset in the compilation unit.
size_t WriteTypeDeclaration(const std::string& desc) {
using namespace dwarf; // NOLINT. For easy access to DWARF constants.
DCHECK(!desc.empty());
const auto it = type_cache_.find(desc);
if (it != type_cache_.end()) {
return it->second;
}
size_t offset;
if (desc[0] == 'L') {
// Class type. For example: Lpackage/name;
size_t class_offset = StartClassTag(desc.c_str());
info_.WriteFlagPresent(DW_AT_declaration);
EndClassTag();
// Reference to the class type.
offset = info_.StartTag(DW_TAG_reference_type);
info_.WriteRef(DW_AT_type, class_offset);
info_.EndTag();
} else if (desc[0] == '[') {
// Array type.
size_t element_type = WriteTypeDeclaration(desc.substr(1));
CloseNamespacesAboveDepth(0); // Declare in root namespace.
size_t array_type = info_.StartTag(DW_TAG_array_type);
info_.WriteFlagPresent(DW_AT_declaration);
info_.WriteRef(DW_AT_type, element_type);
info_.EndTag();
offset = info_.StartTag(DW_TAG_reference_type);
info_.WriteRef4(DW_AT_type, array_type);
info_.EndTag();
} else {
// Primitive types.
DCHECK_EQ(desc.size(), 1u);
const char* name;
uint32_t encoding;
uint32_t byte_size;
switch (desc[0]) {
case 'B':
name = "byte";
encoding = DW_ATE_signed;
byte_size = 1;
break;
case 'C':
name = "char";
encoding = DW_ATE_UTF;
byte_size = 2;
break;
case 'D':
name = "double";
encoding = DW_ATE_float;
byte_size = 8;
break;
case 'F':
name = "float";
encoding = DW_ATE_float;
byte_size = 4;
break;
case 'I':
name = "int";
encoding = DW_ATE_signed;
byte_size = 4;
break;
case 'J':
name = "long";
encoding = DW_ATE_signed;
byte_size = 8;
break;
case 'S':
name = "short";
encoding = DW_ATE_signed;
byte_size = 2;
break;
case 'Z':
name = "boolean";
encoding = DW_ATE_boolean;
byte_size = 1;
break;
case 'V':
LOG(FATAL) << "Void type should not be encoded";
UNREACHABLE();
default:
LOG(FATAL) << "Unknown dex type descriptor: \"" << desc << "\"";
UNREACHABLE();
}
CloseNamespacesAboveDepth(0); // Declare in root namespace.
offset = info_.StartTag(DW_TAG_base_type);
WriteName(name);
info_.WriteData1(DW_AT_encoding, encoding);
info_.WriteData1(DW_AT_byte_size, byte_size);
info_.EndTag();
}
type_cache_.emplace(desc, offset);
return offset;
}
// Start DW_TAG_class_type tag nested in DW_TAG_namespace tags.
// Returns offset of the class tag in the compilation unit.
size_t StartClassTag(const char* desc) {
std::string name = SetNamespaceForClass(desc);
size_t offset = info_.StartTag(dwarf::DW_TAG_class_type);
WriteName(name.c_str());
return offset;
}
void EndClassTag() {
info_.EndTag();
}
// Set the current namespace nesting to one required by the given class.
// Returns the class name with namespaces, 'L', and ';' stripped.
std::string SetNamespaceForClass(const char* desc) {
DCHECK(desc != nullptr && desc[0] == 'L');
desc++; // Skip the initial 'L'.
size_t depth = 0;
for (const char* end; (end = strchr(desc, '/')) != nullptr; desc = end + 1, ++depth) {
// Check whether the name at this depth is already what we need.
if (depth < current_namespace_.size()) {
const std::string& name = current_namespace_[depth];
if (name.compare(0, name.size(), desc, end - desc) == 0) {
continue;
}
}
// Otherwise we need to open a new namespace tag at this depth.
CloseNamespacesAboveDepth(depth);
info_.StartTag(dwarf::DW_TAG_namespace);
std::string name(desc, end - desc);
WriteName(name.c_str());
current_namespace_.push_back(std::move(name));
}
CloseNamespacesAboveDepth(depth);
return std::string(desc, strchr(desc, ';') - desc);
}
// Close namespace tags to reach the given nesting depth.
void CloseNamespacesAboveDepth(size_t depth) {
DCHECK_LE(depth, current_namespace_.size());
while (current_namespace_.size() > depth) {
info_.EndTag();
current_namespace_.pop_back();
}
}
// For access to the ELF sections.
ElfDebugInfoWriter<ElfTypes>* owner_;
// Temporary buffer to create and store the entries.
dwarf::DebugInfoEntryWriter<> info_;
// Cache of already translated type descriptors.
std::map<std::string, size_t> type_cache_; // type_desc -> definition_offset.
// 32-bit references which need to be resolved to a type later.
// Given type may be used multiple times. Therefore we need a multimap.
std::multimap<std::string, size_t> lazy_types_; // type_desc -> patch_offset.
// The current set of open namespace tags which are active and not closed yet.
std::vector<std::string> current_namespace_;
};
} // namespace debug
} // namespace art
#endif // ART_COMPILER_DEBUG_ELF_DEBUG_INFO_WRITER_H_