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//===-- ObjCLanguageRuntime.cpp -------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#include "clang/AST/Type.h"
#include "ObjCLanguageRuntime.h"
#include "Plugins/TypeSystem/Clang/TypeSystemClang.h"
#include "lldb/Core/MappedHash.h"
#include "lldb/Core/Module.h"
#include "lldb/Core/PluginManager.h"
#include "lldb/Core/ValueObject.h"
#include "lldb/Symbol/SymbolContext.h"
#include "lldb/Symbol/SymbolFile.h"
#include "lldb/Symbol/Type.h"
#include "lldb/Symbol/TypeList.h"
#include "lldb/Symbol/Variable.h"
#include "lldb/Target/Target.h"
#include "lldb/Utility/Log.h"
#include "lldb/Utility/Timer.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/Support/DJB.h"
using namespace lldb;
using namespace lldb_private;
char ObjCLanguageRuntime::ID = 0;
// Destructor
ObjCLanguageRuntime::~ObjCLanguageRuntime() {}
ObjCLanguageRuntime::ObjCLanguageRuntime(Process *process)
: LanguageRuntime(process), m_impl_cache(),
m_has_new_literals_and_indexing(eLazyBoolCalculate),
m_isa_to_descriptor(), m_hash_to_isa_map(), m_type_size_cache(),
m_isa_to_descriptor_stop_id(UINT32_MAX), m_complete_class_cache(),
m_negative_complete_class_cache() {}
bool ObjCLanguageRuntime::IsAllowedRuntimeValue(ConstString name) {
static ConstString g_self = ConstString("self");
static ConstString g_cmd = ConstString("_cmd");
return name == g_self || name == g_cmd;
}
bool ObjCLanguageRuntime::AddClass(ObjCISA isa,
const ClassDescriptorSP &descriptor_sp,
const char *class_name) {
if (isa != 0) {
m_isa_to_descriptor[isa] = descriptor_sp;
// class_name is assumed to be valid
m_hash_to_isa_map.insert(std::make_pair(llvm::djbHash(class_name), isa));
return true;
}
return false;
}
void ObjCLanguageRuntime::AddToMethodCache(lldb::addr_t class_addr,
lldb::addr_t selector,
lldb::addr_t impl_addr) {
Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_STEP));
if (log) {
LLDB_LOGF(log,
"Caching: class 0x%" PRIx64 " selector 0x%" PRIx64
" implementation 0x%" PRIx64 ".",
class_addr, selector, impl_addr);
}
m_impl_cache.insert(std::pair<ClassAndSel, lldb::addr_t>(
ClassAndSel(class_addr, selector), impl_addr));
}
lldb::addr_t ObjCLanguageRuntime::LookupInMethodCache(lldb::addr_t class_addr,
lldb::addr_t selector) {
MsgImplMap::iterator pos, end = m_impl_cache.end();
pos = m_impl_cache.find(ClassAndSel(class_addr, selector));
if (pos != end)
return (*pos).second;
return LLDB_INVALID_ADDRESS;
}
lldb::TypeSP
ObjCLanguageRuntime::LookupInCompleteClassCache(ConstString &name) {
CompleteClassMap::iterator complete_class_iter =
m_complete_class_cache.find(name);
if (complete_class_iter != m_complete_class_cache.end()) {
// Check the weak pointer to make sure the type hasn't been unloaded
TypeSP complete_type_sp(complete_class_iter->second.lock());
if (complete_type_sp)
return complete_type_sp;
else
m_complete_class_cache.erase(name);
}
if (m_negative_complete_class_cache.count(name) > 0)
return TypeSP();
const ModuleList &modules = m_process->GetTarget().GetImages();
SymbolContextList sc_list;
modules.FindSymbolsWithNameAndType(name, eSymbolTypeObjCClass, sc_list);
const size_t matching_symbols = sc_list.GetSize();
if (matching_symbols) {
SymbolContext sc;
sc_list.GetContextAtIndex(0, sc);
ModuleSP module_sp(sc.module_sp);
if (!module_sp)
return TypeSP();
const bool exact_match = true;
const uint32_t max_matches = UINT32_MAX;
TypeList types;
llvm::DenseSet<SymbolFile *> searched_symbol_files;
module_sp->FindTypes(name, exact_match, max_matches, searched_symbol_files,
types);
for (uint32_t i = 0; i < types.GetSize(); ++i) {
TypeSP type_sp(types.GetTypeAtIndex(i));
if (TypeSystemClang::IsObjCObjectOrInterfaceType(
type_sp->GetForwardCompilerType())) {
if (TypePayloadClang(type_sp->GetPayload()).IsCompleteObjCClass()) {
m_complete_class_cache[name] = type_sp;
return type_sp;
}
}
}
}
m_negative_complete_class_cache.insert(name);
return TypeSP();
}
size_t ObjCLanguageRuntime::GetByteOffsetForIvar(CompilerType &parent_qual_type,
const char *ivar_name) {
return LLDB_INVALID_IVAR_OFFSET;
}
bool ObjCLanguageRuntime::ClassDescriptor::IsPointerValid(
lldb::addr_t value, uint32_t ptr_size, bool allow_NULLs, bool allow_tagged,
bool check_version_specific) const {
if (!value)
return allow_NULLs;
if ((value % 2) == 1 && allow_tagged)
return true;
if ((value % ptr_size) == 0)
return (check_version_specific ? CheckPointer(value, ptr_size) : true);
else
return false;
}
ObjCLanguageRuntime::ObjCISA
ObjCLanguageRuntime::GetISA(ConstString name) {
ISAToDescriptorIterator pos = GetDescriptorIterator(name);
if (pos != m_isa_to_descriptor.end())
return pos->first;
return 0;
}
ObjCLanguageRuntime::ISAToDescriptorIterator
ObjCLanguageRuntime::GetDescriptorIterator(ConstString name) {
ISAToDescriptorIterator end = m_isa_to_descriptor.end();
if (name) {
UpdateISAToDescriptorMap();
if (m_hash_to_isa_map.empty()) {
// No name hashes were provided, we need to just linearly power through
// the names and find a match
for (ISAToDescriptorIterator pos = m_isa_to_descriptor.begin();
pos != end; ++pos) {
if (pos->second->GetClassName() == name)
return pos;
}
} else {
// Name hashes were provided, so use them to efficiently lookup name to
// isa/descriptor
const uint32_t name_hash = llvm::djbHash(name.GetStringRef());
std::pair<HashToISAIterator, HashToISAIterator> range =
m_hash_to_isa_map.equal_range(name_hash);
for (HashToISAIterator range_pos = range.first; range_pos != range.second;
++range_pos) {
ISAToDescriptorIterator pos =
m_isa_to_descriptor.find(range_pos->second);
if (pos != m_isa_to_descriptor.end()) {
if (pos->second->GetClassName() == name)
return pos;
}
}
}
}
return end;
}
std::pair<ObjCLanguageRuntime::ISAToDescriptorIterator,
ObjCLanguageRuntime::ISAToDescriptorIterator>
ObjCLanguageRuntime::GetDescriptorIteratorPair(bool update_if_needed) {
if (update_if_needed)
UpdateISAToDescriptorMapIfNeeded();
return std::pair<ObjCLanguageRuntime::ISAToDescriptorIterator,
ObjCLanguageRuntime::ISAToDescriptorIterator>(
m_isa_to_descriptor.begin(), m_isa_to_descriptor.end());
}
ObjCLanguageRuntime::ObjCISA
ObjCLanguageRuntime::GetParentClass(ObjCLanguageRuntime::ObjCISA isa) {
ClassDescriptorSP objc_class_sp(GetClassDescriptorFromISA(isa));
if (objc_class_sp) {
ClassDescriptorSP objc_super_class_sp(objc_class_sp->GetSuperclass());
if (objc_super_class_sp)
return objc_super_class_sp->GetISA();
}
return 0;
}
ObjCLanguageRuntime::ClassDescriptorSP
ObjCLanguageRuntime::GetClassDescriptorFromClassName(
ConstString class_name) {
ISAToDescriptorIterator pos = GetDescriptorIterator(class_name);
if (pos != m_isa_to_descriptor.end())
return pos->second;
return ClassDescriptorSP();
}
ObjCLanguageRuntime::ClassDescriptorSP
ObjCLanguageRuntime::GetClassDescriptor(ValueObject &valobj) {
ClassDescriptorSP objc_class_sp;
// if we get an invalid VO (which might still happen when playing around with
// pointers returned by the expression parser, don't consider this a valid
// ObjC object)
if (valobj.GetCompilerType().IsValid()) {
addr_t isa_pointer = valobj.GetPointerValue();
if (isa_pointer != LLDB_INVALID_ADDRESS) {
ExecutionContext exe_ctx(valobj.GetExecutionContextRef());
Process *process = exe_ctx.GetProcessPtr();
if (process) {
Status error;
ObjCISA isa = process->ReadPointerFromMemory(isa_pointer, error);
if (isa != LLDB_INVALID_ADDRESS)
objc_class_sp = GetClassDescriptorFromISA(isa);
}
}
}
return objc_class_sp;
}
ObjCLanguageRuntime::ClassDescriptorSP
ObjCLanguageRuntime::GetNonKVOClassDescriptor(ValueObject &valobj) {
ObjCLanguageRuntime::ClassDescriptorSP objc_class_sp(
GetClassDescriptor(valobj));
if (objc_class_sp) {
if (!objc_class_sp->IsKVO())
return objc_class_sp;
ClassDescriptorSP non_kvo_objc_class_sp(objc_class_sp->GetSuperclass());
if (non_kvo_objc_class_sp && non_kvo_objc_class_sp->IsValid())
return non_kvo_objc_class_sp;
}
return ClassDescriptorSP();
}
ObjCLanguageRuntime::ClassDescriptorSP
ObjCLanguageRuntime::GetClassDescriptorFromISA(ObjCISA isa) {
if (isa) {
UpdateISAToDescriptorMap();
ObjCLanguageRuntime::ISAToDescriptorIterator pos =
m_isa_to_descriptor.find(isa);
if (pos != m_isa_to_descriptor.end())
return pos->second;
}
return ClassDescriptorSP();
}
ObjCLanguageRuntime::ClassDescriptorSP
ObjCLanguageRuntime::GetNonKVOClassDescriptor(ObjCISA isa) {
if (isa) {
ClassDescriptorSP objc_class_sp = GetClassDescriptorFromISA(isa);
if (objc_class_sp && objc_class_sp->IsValid()) {
if (!objc_class_sp->IsKVO())
return objc_class_sp;
ClassDescriptorSP non_kvo_objc_class_sp(objc_class_sp->GetSuperclass());
if (non_kvo_objc_class_sp && non_kvo_objc_class_sp->IsValid())
return non_kvo_objc_class_sp;
}
}
return ClassDescriptorSP();
}
CompilerType
ObjCLanguageRuntime::EncodingToType::RealizeType(const char *name,
bool for_expression) {
if (m_scratch_ast_ctx_up)
return RealizeType(*m_scratch_ast_ctx_up, name, for_expression);
return CompilerType();
}
ObjCLanguageRuntime::EncodingToType::~EncodingToType() {}
ObjCLanguageRuntime::EncodingToTypeSP ObjCLanguageRuntime::GetEncodingToType() {
return nullptr;
}
bool ObjCLanguageRuntime::GetTypeBitSize(const CompilerType &compiler_type,
uint64_t &size) {
void *opaque_ptr = compiler_type.GetOpaqueQualType();
size = m_type_size_cache.Lookup(opaque_ptr);
// an ObjC object will at least have an ISA, so 0 is definitely not OK
if (size > 0)
return true;
ClassDescriptorSP class_descriptor_sp =
GetClassDescriptorFromClassName(compiler_type.GetTypeName());
if (!class_descriptor_sp)
return false;
int32_t max_offset = INT32_MIN;
uint64_t sizeof_max = 0;
bool found = false;
for (size_t idx = 0; idx < class_descriptor_sp->GetNumIVars(); idx++) {
const auto &ivar = class_descriptor_sp->GetIVarAtIndex(idx);
int32_t cur_offset = ivar.m_offset;
if (cur_offset > max_offset) {
max_offset = cur_offset;
sizeof_max = ivar.m_size;
found = true;
}
}
size = 8 * (max_offset + sizeof_max);
if (found)
m_type_size_cache.Insert(opaque_ptr, size);
return found;
}
lldb::BreakpointPreconditionSP
ObjCLanguageRuntime::GetBreakpointExceptionPrecondition(LanguageType language,
bool throw_bp) {
if (language != eLanguageTypeObjC)
return lldb::BreakpointPreconditionSP();
if (!throw_bp)
return lldb::BreakpointPreconditionSP();
BreakpointPreconditionSP precondition_sp(
new ObjCLanguageRuntime::ObjCExceptionPrecondition());
return precondition_sp;
}
// Exception breakpoint Precondition class for ObjC:
void ObjCLanguageRuntime::ObjCExceptionPrecondition::AddClassName(
const char *class_name) {
m_class_names.insert(class_name);
}
ObjCLanguageRuntime::ObjCExceptionPrecondition::ObjCExceptionPrecondition() {}
bool ObjCLanguageRuntime::ObjCExceptionPrecondition::EvaluatePrecondition(
StoppointCallbackContext &context) {
return true;
}
void ObjCLanguageRuntime::ObjCExceptionPrecondition::GetDescription(
Stream &stream, lldb::DescriptionLevel level) {}
Status ObjCLanguageRuntime::ObjCExceptionPrecondition::ConfigurePrecondition(
Args &args) {
Status error;
if (args.GetArgumentCount() > 0)
error.SetErrorString(
"The ObjC Exception breakpoint doesn't support extra options.");
return error;
}
llvm::Optional<CompilerType>
ObjCLanguageRuntime::GetRuntimeType(CompilerType base_type) {
CompilerType class_type;
bool is_pointer_type = false;
if (TypeSystemClang::IsObjCObjectPointerType(base_type, &class_type))
is_pointer_type = true;
else if (TypeSystemClang::IsObjCObjectOrInterfaceType(base_type))
class_type = base_type;
else
return llvm::None;
if (!class_type)
return llvm::None;
ConstString class_name(class_type.GetTypeName());
if (!class_name)
return llvm::None;
TypeSP complete_objc_class_type_sp = LookupInCompleteClassCache(class_name);
if (!complete_objc_class_type_sp)
return llvm::None;
CompilerType complete_class(
complete_objc_class_type_sp->GetFullCompilerType());
if (complete_class.GetCompleteType()) {
if (is_pointer_type)
return complete_class.GetPointerType();
else
return complete_class;
}
return llvm::None;
}