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//===-- ABI.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 "lldb/Target/ABI.h"
#include "lldb/Core/PluginManager.h"
#include "lldb/Core/Value.h"
#include "lldb/Core/ValueObjectConstResult.h"
#include "lldb/Expression/ExpressionVariable.h"
#include "lldb/Symbol/CompilerType.h"
#include "lldb/Symbol/TypeSystem.h"
#include "lldb/Target/Target.h"
#include "lldb/Target/Thread.h"
#include "lldb/Utility/Log.h"
#include "llvm/Support/TargetRegistry.h"
#include <cctype>
using namespace lldb;
using namespace lldb_private;
ABISP
ABI::FindPlugin(lldb::ProcessSP process_sp, const ArchSpec &arch) {
ABISP abi_sp;
ABICreateInstance create_callback;
for (uint32_t idx = 0;
(create_callback = PluginManager::GetABICreateCallbackAtIndex(idx)) !=
nullptr;
++idx) {
abi_sp = create_callback(process_sp, arch);
if (abi_sp)
return abi_sp;
}
abi_sp.reset();
return abi_sp;
}
ABI::~ABI() = default;
bool RegInfoBasedABI::GetRegisterInfoByName(llvm::StringRef name,
RegisterInfo &info) {
uint32_t count = 0;
const RegisterInfo *register_info_array = GetRegisterInfoArray(count);
if (register_info_array) {
uint32_t i;
for (i = 0; i < count; ++i) {
const char *reg_name = register_info_array[i].name;
if (reg_name == name) {
info = register_info_array[i];
return true;
}
}
for (i = 0; i < count; ++i) {
const char *reg_alt_name = register_info_array[i].alt_name;
if (reg_alt_name == name) {
info = register_info_array[i];
return true;
}
}
}
return false;
}
ValueObjectSP ABI::GetReturnValueObject(Thread &thread, CompilerType &ast_type,
bool persistent) const {
if (!ast_type.IsValid())
return ValueObjectSP();
ValueObjectSP return_valobj_sp;
return_valobj_sp = GetReturnValueObjectImpl(thread, ast_type);
if (!return_valobj_sp)
return return_valobj_sp;
// Now turn this into a persistent variable.
// FIXME: This code is duplicated from Target::EvaluateExpression, and it is
// used in similar form in a couple
// of other places. Figure out the correct Create function to do all this
// work.
if (persistent) {
Target &target = *thread.CalculateTarget();
PersistentExpressionState *persistent_expression_state =
target.GetPersistentExpressionStateForLanguage(
ast_type.GetMinimumLanguage());
if (!persistent_expression_state)
return {};
ConstString persistent_variable_name =
persistent_expression_state->GetNextPersistentVariableName();
lldb::ValueObjectSP const_valobj_sp;
// Check in case our value is already a constant value
if (return_valobj_sp->GetIsConstant()) {
const_valobj_sp = return_valobj_sp;
const_valobj_sp->SetName(persistent_variable_name);
} else
const_valobj_sp =
return_valobj_sp->CreateConstantValue(persistent_variable_name);
lldb::ValueObjectSP live_valobj_sp = return_valobj_sp;
return_valobj_sp = const_valobj_sp;
ExpressionVariableSP expr_variable_sp(
persistent_expression_state->CreatePersistentVariable(
return_valobj_sp));
assert(expr_variable_sp);
// Set flags and live data as appropriate
const Value &result_value = live_valobj_sp->GetValue();
switch (result_value.GetValueType()) {
case Value::eValueTypeHostAddress:
case Value::eValueTypeFileAddress:
// we don't do anything with these for now
break;
case Value::eValueTypeScalar:
expr_variable_sp->m_flags |=
ExpressionVariable::EVIsFreezeDried;
expr_variable_sp->m_flags |=
ExpressionVariable::EVIsLLDBAllocated;
expr_variable_sp->m_flags |=
ExpressionVariable::EVNeedsAllocation;
break;
case Value::eValueTypeLoadAddress:
expr_variable_sp->m_live_sp = live_valobj_sp;
expr_variable_sp->m_flags |=
ExpressionVariable::EVIsProgramReference;
break;
}
return_valobj_sp = expr_variable_sp->GetValueObject();
}
return return_valobj_sp;
}
ValueObjectSP ABI::GetReturnValueObject(Thread &thread, llvm::Type &ast_type,
bool persistent) const {
ValueObjectSP return_valobj_sp;
return_valobj_sp = GetReturnValueObjectImpl(thread, ast_type);
return return_valobj_sp;
}
// specialized to work with llvm IR types
//
// for now we will specify a default implementation so that we don't need to
// modify other ABIs
lldb::ValueObjectSP ABI::GetReturnValueObjectImpl(Thread &thread,
llvm::Type &ir_type) const {
ValueObjectSP return_valobj_sp;
/* this is a dummy and will only be called if an ABI does not override this */
return return_valobj_sp;
}
bool ABI::PrepareTrivialCall(Thread &thread, lldb::addr_t sp,
lldb::addr_t functionAddress,
lldb::addr_t returnAddress, llvm::Type &returntype,
llvm::ArrayRef<ABI::CallArgument> args) const {
// dummy prepare trivial call
llvm_unreachable("Should never get here!");
}
bool ABI::GetFallbackRegisterLocation(
const RegisterInfo *reg_info,
UnwindPlan::Row::RegisterLocation &unwind_regloc) {
// Did the UnwindPlan fail to give us the caller's stack pointer? The stack
// pointer is defined to be the same as THIS frame's CFA, so return the CFA
// value as the caller's stack pointer. This is true on x86-32/x86-64 at
// least.
if (reg_info->kinds[eRegisterKindGeneric] == LLDB_REGNUM_GENERIC_SP) {
unwind_regloc.SetIsCFAPlusOffset(0);
return true;
}
// If a volatile register is being requested, we don't want to forward the
// next frame's register contents up the stack -- the register is not
// retrievable at this frame.
if (RegisterIsVolatile(reg_info)) {
unwind_regloc.SetUndefined();
return true;
}
return false;
}
std::unique_ptr<llvm::MCRegisterInfo> ABI::MakeMCRegisterInfo(const ArchSpec &arch) {
std::string triple = arch.GetTriple().getTriple();
std::string lookup_error;
const llvm::Target *target =
llvm::TargetRegistry::lookupTarget(triple, lookup_error);
if (!target) {
LLDB_LOG(GetLogIfAllCategoriesSet(LIBLLDB_LOG_PROCESS),
"Failed to create an llvm target for {0}: {1}", triple,
lookup_error);
return nullptr;
}
std::unique_ptr<llvm::MCRegisterInfo> info_up(
target->createMCRegInfo(triple));
assert(info_up);
return info_up;
}
void RegInfoBasedABI::AugmentRegisterInfo(RegisterInfo &info) {
if (info.kinds[eRegisterKindEHFrame] != LLDB_INVALID_REGNUM &&
info.kinds[eRegisterKindDWARF] != LLDB_INVALID_REGNUM)
return;
RegisterInfo abi_info;
if (!GetRegisterInfoByName(info.name, abi_info))
return;
if (info.kinds[eRegisterKindEHFrame] == LLDB_INVALID_REGNUM)
info.kinds[eRegisterKindEHFrame] = abi_info.kinds[eRegisterKindEHFrame];
if (info.kinds[eRegisterKindDWARF] == LLDB_INVALID_REGNUM)
info.kinds[eRegisterKindDWARF] = abi_info.kinds[eRegisterKindDWARF];
if (info.kinds[eRegisterKindGeneric] == LLDB_INVALID_REGNUM)
info.kinds[eRegisterKindGeneric] = abi_info.kinds[eRegisterKindGeneric];
}
void MCBasedABI::AugmentRegisterInfo(RegisterInfo &info) {
uint32_t eh, dwarf;
std::tie(eh, dwarf) = GetEHAndDWARFNums(info.name);
if (info.kinds[eRegisterKindEHFrame] == LLDB_INVALID_REGNUM)
info.kinds[eRegisterKindEHFrame] = eh;
if (info.kinds[eRegisterKindDWARF] == LLDB_INVALID_REGNUM)
info.kinds[eRegisterKindDWARF] = dwarf;
if (info.kinds[eRegisterKindGeneric] == LLDB_INVALID_REGNUM)
info.kinds[eRegisterKindGeneric] = GetGenericNum(info.name);
}
std::pair<uint32_t, uint32_t>
MCBasedABI::GetEHAndDWARFNums(llvm::StringRef name) {
std::string mc_name = GetMCName(name.str());
for (char &c : mc_name)
c = std::toupper(c);
int eh = -1;
int dwarf = -1;
for (unsigned reg = 0; reg < m_mc_register_info_up->getNumRegs(); ++reg) {
if (m_mc_register_info_up->getName(reg) == mc_name) {
eh = m_mc_register_info_up->getDwarfRegNum(reg, /*isEH=*/true);
dwarf = m_mc_register_info_up->getDwarfRegNum(reg, /*isEH=*/false);
break;
}
}
return std::pair<uint32_t, uint32_t>(eh == -1 ? LLDB_INVALID_REGNUM : eh,
dwarf == -1 ? LLDB_INVALID_REGNUM
: dwarf);
}
void MCBasedABI::MapRegisterName(std::string &name, llvm::StringRef from_prefix,
llvm::StringRef to_prefix) {
llvm::StringRef name_ref = name;
if (!name_ref.consume_front(from_prefix))
return;
uint64_t _;
if (name_ref.empty() || to_integer(name_ref, _, 10))
name = (to_prefix + name_ref).str();
}