911 lines · cpp
1//===-- ABISysV_riscv.cpp ------------------------------------------------===//2//3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.4// See https://llvm.org/LICENSE.txt for license information.5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception6//7//===---------------------------------------------------------------------===//8 9#include "ABISysV_riscv.h"10 11#include <array>12#include <limits>13#include <sstream>14 15#include "llvm/ADT/STLExtras.h"16#include "llvm/IR/DerivedTypes.h"17 18#include "Utility/RISCV_DWARF_Registers.h"19#include "lldb/Core/PluginManager.h"20#include "lldb/Core/Value.h"21#include "lldb/Target/RegisterContext.h"22#include "lldb/Target/StackFrame.h"23#include "lldb/Target/Thread.h"24#include "lldb/Utility/LLDBLog.h"25#include "lldb/Utility/RegisterValue.h"26#include "lldb/ValueObject/ValueObjectConstResult.h"27 28#define DEFINE_REG_NAME(reg_num) ConstString(#reg_num).GetCString()29#define DEFINE_REG_NAME_STR(reg_name) ConstString(reg_name).GetCString()30 31// The ABI is not a source of such information as size, offset, encoding, etc.32// of a register. Just provides correct dwarf and eh_frame numbers.33 34#define DEFINE_GENERIC_REGISTER_STUB(dwarf_num, str_name, generic_num) \35 { \36 DEFINE_REG_NAME(dwarf_num), DEFINE_REG_NAME_STR(str_name), 0, 0, \37 eEncodingInvalid, eFormatDefault, \38 {dwarf_num, dwarf_num, generic_num, LLDB_INVALID_REGNUM, dwarf_num}, \39 nullptr, nullptr, nullptr, \40 }41 42#define DEFINE_REGISTER_STUB(dwarf_num, str_name) \43 DEFINE_GENERIC_REGISTER_STUB(dwarf_num, str_name, LLDB_INVALID_REGNUM)44 45using namespace lldb;46using namespace lldb_private;47 48LLDB_PLUGIN_DEFINE_ADV(ABISysV_riscv, ABIRISCV)49 50namespace {51namespace dwarf {52enum regnums {53 zero,54 ra,55 sp,56 gp,57 tp,58 t0,59 t1,60 t2,61 fp,62 s0 = fp,63 s1,64 a0,65 a1,66 a2,67 a3,68 a4,69 a5,70 a6,71 a7,72 s2,73 s3,74 s4,75 s5,76 s6,77 s7,78 s8,79 s9,80 s10,81 s11,82 t3,83 t4,84 t5,85 t6,86 pc87};88 89static const std::array<RegisterInfo, 33> g_register_infos = {90 {DEFINE_REGISTER_STUB(zero, nullptr),91 DEFINE_GENERIC_REGISTER_STUB(ra, nullptr, LLDB_REGNUM_GENERIC_RA),92 DEFINE_GENERIC_REGISTER_STUB(sp, nullptr, LLDB_REGNUM_GENERIC_SP),93 DEFINE_REGISTER_STUB(gp, nullptr),94 DEFINE_REGISTER_STUB(tp, nullptr),95 DEFINE_REGISTER_STUB(t0, nullptr),96 DEFINE_REGISTER_STUB(t1, nullptr),97 DEFINE_REGISTER_STUB(t2, nullptr),98 DEFINE_GENERIC_REGISTER_STUB(fp, nullptr, LLDB_REGNUM_GENERIC_FP),99 DEFINE_REGISTER_STUB(s1, nullptr),100 DEFINE_GENERIC_REGISTER_STUB(a0, nullptr, LLDB_REGNUM_GENERIC_ARG1),101 DEFINE_GENERIC_REGISTER_STUB(a1, nullptr, LLDB_REGNUM_GENERIC_ARG2),102 DEFINE_GENERIC_REGISTER_STUB(a2, nullptr, LLDB_REGNUM_GENERIC_ARG3),103 DEFINE_GENERIC_REGISTER_STUB(a3, nullptr, LLDB_REGNUM_GENERIC_ARG4),104 DEFINE_GENERIC_REGISTER_STUB(a4, nullptr, LLDB_REGNUM_GENERIC_ARG5),105 DEFINE_GENERIC_REGISTER_STUB(a5, nullptr, LLDB_REGNUM_GENERIC_ARG6),106 DEFINE_GENERIC_REGISTER_STUB(a6, nullptr, LLDB_REGNUM_GENERIC_ARG7),107 DEFINE_GENERIC_REGISTER_STUB(a7, nullptr, LLDB_REGNUM_GENERIC_ARG8),108 DEFINE_REGISTER_STUB(s2, nullptr),109 DEFINE_REGISTER_STUB(s3, nullptr),110 DEFINE_REGISTER_STUB(s4, nullptr),111 DEFINE_REGISTER_STUB(s5, nullptr),112 DEFINE_REGISTER_STUB(s6, nullptr),113 DEFINE_REGISTER_STUB(s7, nullptr),114 DEFINE_REGISTER_STUB(s8, nullptr),115 DEFINE_REGISTER_STUB(s9, nullptr),116 DEFINE_REGISTER_STUB(s10, nullptr),117 DEFINE_REGISTER_STUB(s11, nullptr),118 DEFINE_REGISTER_STUB(t3, nullptr),119 DEFINE_REGISTER_STUB(t4, nullptr),120 DEFINE_REGISTER_STUB(t5, nullptr),121 DEFINE_REGISTER_STUB(t6, nullptr),122 DEFINE_GENERIC_REGISTER_STUB(pc, nullptr, LLDB_REGNUM_GENERIC_PC)}};123} // namespace dwarf124} // namespace125 126// Number of argument registers (the base integer calling convention127// provides 8 argument registers, a0-a7)128static constexpr size_t g_regs_for_args_count = 8U;129 130const RegisterInfo *ABISysV_riscv::GetRegisterInfoArray(uint32_t &count) {131 count = dwarf::g_register_infos.size();132 return dwarf::g_register_infos.data();133}134 135//------------------------------------------------------------------136// Static Functions137//------------------------------------------------------------------138 139ABISP140ABISysV_riscv::CreateInstance(ProcessSP process_sp, const ArchSpec &arch) {141 llvm::Triple::ArchType machine = arch.GetTriple().getArch();142 143 if (llvm::Triple::riscv32 != machine && llvm::Triple::riscv64 != machine)144 return ABISP();145 146 ABISysV_riscv *abi = new ABISysV_riscv(std::move(process_sp),147 MakeMCRegisterInfo(arch));148 if (abi)149 abi->SetIsRV64((llvm::Triple::riscv64 == machine) ? true : false);150 return ABISP(abi);151}152 153static inline size_t AugmentArgSize(bool is_rv64, size_t size_in_bytes) {154 size_t word_size = is_rv64 ? 8 : 4;155 return llvm::alignTo(size_in_bytes, word_size);156}157 158static size_t159TotalArgsSizeInWords(bool is_rv64,160 const llvm::ArrayRef<ABI::CallArgument> &args) {161 size_t reg_size = is_rv64 ? 8 : 4;162 size_t word_size = reg_size;163 size_t total_size = 0;164 for (const auto &arg : args)165 total_size +=166 (ABI::CallArgument::TargetValue == arg.type ? AugmentArgSize(is_rv64,167 arg.size)168 : reg_size) /169 word_size;170 171 return total_size;172}173 174static bool UpdateRegister(RegisterContext *reg_ctx,175 const lldb::RegisterKind reg_kind,176 const uint32_t reg_num, const addr_t value) {177 Log *log = GetLog(LLDBLog::Expressions);178 179 const RegisterInfo *reg_info = reg_ctx->GetRegisterInfo(reg_kind, reg_num);180 181 LLDB_LOG(log, "Writing {0}: 0x{1:x}", reg_info->name,182 static_cast<uint64_t>(value));183 if (!reg_ctx->WriteRegisterFromUnsigned(reg_info, value)) {184 LLDB_LOG(log, "Writing {0}: failed", reg_info->name);185 return false;186 }187 return true;188}189 190static void LogInitInfo(Log &log, const Thread &thread, addr_t sp,191 addr_t func_addr, addr_t return_addr,192 const llvm::ArrayRef<addr_t> args) {193 std::stringstream ss;194 ss << "ABISysV_riscv::PrepareTrivialCall"195 << " (tid = 0x" << std::hex << thread.GetID() << ", sp = 0x" << sp196 << ", func_addr = 0x" << func_addr << ", return_addr = 0x" << return_addr;197 198 for (auto [idx, arg] : enumerate(args))199 ss << ", arg" << std::dec << idx << " = 0x" << std::hex << arg;200 ss << ")";201 log.PutString(ss.str());202}203 204bool ABISysV_riscv::PrepareTrivialCall(Thread &thread, addr_t sp,205 addr_t func_addr, addr_t return_addr,206 llvm::ArrayRef<addr_t> args) const {207 Log *log = GetLog(LLDBLog::Expressions);208 if (log)209 LogInitInfo(*log, thread, sp, func_addr, return_addr, args);210 211 const auto reg_ctx_sp = thread.GetRegisterContext();212 if (!reg_ctx_sp) {213 LLDB_LOG(log, "Failed to get RegisterContext");214 return false;215 }216 217 if (args.size() > g_regs_for_args_count) {218 LLDB_LOG(log, "Function has {0} arguments, but only {1} are allowed!",219 args.size(), g_regs_for_args_count);220 return false;221 }222 223 // Write arguments to registers224 for (auto [idx, arg] : enumerate(args)) {225 const RegisterInfo *reg_info = reg_ctx_sp->GetRegisterInfo(226 eRegisterKindGeneric, LLDB_REGNUM_GENERIC_ARG1 + idx);227 LLDB_LOG(log, "About to write arg{0} (0x{1:x}) into {2}", idx, arg,228 reg_info->name);229 230 if (!reg_ctx_sp->WriteRegisterFromUnsigned(reg_info, arg)) {231 LLDB_LOG(log, "Failed to write arg{0} (0x{1:x}) into {2}", idx, arg,232 reg_info->name);233 return false;234 }235 }236 237 if (!UpdateRegister(reg_ctx_sp.get(), eRegisterKindGeneric,238 LLDB_REGNUM_GENERIC_PC, func_addr))239 return false;240 if (!UpdateRegister(reg_ctx_sp.get(), eRegisterKindGeneric,241 LLDB_REGNUM_GENERIC_SP, sp))242 return false;243 if (!UpdateRegister(reg_ctx_sp.get(), eRegisterKindGeneric,244 LLDB_REGNUM_GENERIC_RA, return_addr))245 return false;246 247 LLDB_LOG(log, "ABISysV_riscv::{0}() success", __FUNCTION__);248 return true;249}250 251bool ABISysV_riscv::PrepareTrivialCall(252 Thread &thread, addr_t sp, addr_t pc, addr_t ra, llvm::Type &prototype,253 llvm::ArrayRef<ABI::CallArgument> args) const {254 auto reg_ctx = thread.GetRegisterContext();255 if (!reg_ctx)256 return false;257 258 uint32_t pc_reg = reg_ctx->ConvertRegisterKindToRegisterNumber(259 eRegisterKindGeneric, LLDB_REGNUM_GENERIC_PC);260 if (pc_reg == LLDB_INVALID_REGNUM)261 return false;262 263 uint32_t ra_reg = reg_ctx->ConvertRegisterKindToRegisterNumber(264 eRegisterKindGeneric, LLDB_REGNUM_GENERIC_RA);265 if (ra_reg == LLDB_INVALID_REGNUM)266 return false;267 268 uint32_t sp_reg = reg_ctx->ConvertRegisterKindToRegisterNumber(269 eRegisterKindGeneric, LLDB_REGNUM_GENERIC_SP);270 if (sp_reg == LLDB_INVALID_REGNUM)271 return false;272 273 Status error;274 ProcessSP process = thread.GetProcess();275 if (!process)276 return false;277 278 size_t reg_size = m_is_rv64 ? 8 : 4;279 size_t word_size = reg_size;280 // Push host data onto target.281 for (const auto &arg : args) {282 // Skip over target values.283 if (arg.type == ABI::CallArgument::TargetValue)284 continue;285 286 // Create space on the host stack for this data 4-byte aligned.287 sp -= AugmentArgSize(m_is_rv64, arg.size);288 289 if (process->WriteMemory(sp, arg.data_up.get(), arg.size, error) <290 arg.size ||291 error.Fail())292 return false;293 294 // Update the argument with the target pointer.295 *const_cast<addr_t *>(&arg.value) = sp;296 }297 298 // Make sure number of parameters matches prototype.299 assert(prototype.getFunctionNumParams() == args.size());300 301 const size_t num_args = args.size();302 const size_t num_args_in_regs =303 num_args > g_regs_for_args_count ? g_regs_for_args_count : num_args;304 305 // Number of arguments passed on stack.306 size_t args_size = TotalArgsSizeInWords(m_is_rv64, args);307 auto on_stack = args_size <= g_regs_for_args_count308 ? 0309 : args_size - g_regs_for_args_count;310 auto offset = on_stack * word_size;311 312 uint8_t reg_value[8];313 size_t reg_index = LLDB_REGNUM_GENERIC_ARG1;314 315 for (size_t i = 0; i < args_size; ++i) {316 auto value = reinterpret_cast<const uint8_t *>(&args[i].value);317 auto size =318 ABI::CallArgument::TargetValue == args[i].type ? args[i].size : reg_size;319 320 // Pass arguments via registers.321 if (i < num_args_in_regs) {322 // copy value to register, padding if arg is smaller than register323 auto end = size < reg_size ? size : reg_size;324 memcpy(reg_value, value, end);325 if (reg_size > end)326 memset(reg_value + end, 0, reg_size - end);327 328 RegisterValue reg_val_obj(llvm::ArrayRef(reg_value, reg_size),329 eByteOrderLittle);330 if (!reg_ctx->WriteRegister(331 reg_ctx->GetRegisterInfo(eRegisterKindGeneric, reg_index),332 reg_val_obj))333 return false;334 335 // NOTE: It's unsafe to iterate through LLDB_REGNUM_GENERICs336 // But the "a" registers are sequential in the RISC-V register space337 ++reg_index;338 }339 340 if (reg_index < g_regs_for_args_count || size == 0)341 continue;342 343 // Remaining arguments are passed on the stack.344 if (process->WriteMemory(sp - offset, value, size, error) < size ||345 !error.Success())346 return false;347 348 offset -= AugmentArgSize(m_is_rv64, size);349 }350 351 // Set stack pointer immediately below arguments.352 sp -= on_stack * word_size;353 354 // Update registers with current function call state.355 reg_ctx->WriteRegisterFromUnsigned(pc_reg, pc);356 reg_ctx->WriteRegisterFromUnsigned(ra_reg, ra);357 reg_ctx->WriteRegisterFromUnsigned(sp_reg, sp);358 359 return true;360}361 362bool ABISysV_riscv::GetArgumentValues(Thread &thread, ValueList &values) const {363 // TODO: Implement364 return false;365}366 367Status ABISysV_riscv::SetReturnValueObject(StackFrameSP &frame_sp,368 ValueObjectSP &new_value_sp) {369 Status result;370 if (!new_value_sp) {371 result = Status::FromErrorString("Empty value object for return value.");372 return result;373 }374 375 CompilerType compiler_type = new_value_sp->GetCompilerType();376 if (!compiler_type) {377 result = Status::FromErrorString("Null clang type for return value.");378 return result;379 }380 381 auto ®_ctx = *frame_sp->GetThread()->GetRegisterContext();382 383 bool is_signed = false;384 if (!compiler_type.IsIntegerOrEnumerationType(is_signed) &&385 !compiler_type.IsPointerType()) {386 result = Status::FromErrorString(387 "We don't support returning other types at present");388 return result;389 }390 391 DataExtractor data;392 size_t num_bytes = new_value_sp->GetData(data, result);393 394 if (result.Fail()) {395 result = Status::FromErrorStringWithFormat(396 "Couldn't convert return value to raw data: %s", result.AsCString());397 return result;398 }399 400 size_t reg_size = m_is_rv64 ? 8 : 4;401 if (num_bytes <= 2 * reg_size) {402 offset_t offset = 0;403 uint64_t raw_value = data.GetMaxU64(&offset, num_bytes);404 405 auto reg_info =406 reg_ctx.GetRegisterInfo(eRegisterKindGeneric, LLDB_REGNUM_GENERIC_ARG1);407 if (!reg_ctx.WriteRegisterFromUnsigned(reg_info, raw_value)) {408 result = Status::FromErrorStringWithFormat(409 "Couldn't write value to register %s", reg_info->name);410 return result;411 }412 413 if (num_bytes <= reg_size)414 return result; // Successfully written.415 416 // for riscv32, get the upper 32 bits from raw_value and write them417 // for riscv64, get the next 64 bits from data and write them418 if (4 == reg_size)419 raw_value >>= 32;420 else421 raw_value = data.GetMaxU64(&offset, num_bytes - reg_size);422 reg_info =423 reg_ctx.GetRegisterInfo(eRegisterKindGeneric, LLDB_REGNUM_GENERIC_ARG2);424 if (!reg_ctx.WriteRegisterFromUnsigned(reg_info, raw_value)) {425 result = Status::FromErrorStringWithFormat(426 "Couldn't write value to register %s", reg_info->name);427 }428 429 return result;430 }431 432 result = Status::FromErrorString(433 "We don't support returning large integer values at present.");434 return result;435}436 437template <typename T>438static void SetInteger(Scalar &scalar, uint64_t raw_value, bool is_signed) {439 raw_value &= std::numeric_limits<T>::max();440 if (is_signed)441 scalar = static_cast<typename std::make_signed<T>::type>(raw_value);442 else443 scalar = static_cast<T>(raw_value);444}445 446static bool SetSizedInteger(Scalar &scalar, uint64_t raw_value,447 uint8_t size_in_bytes, bool is_signed) {448 switch (size_in_bytes) {449 default:450 return false;451 452 case sizeof(uint64_t):453 SetInteger<uint64_t>(scalar, raw_value, is_signed);454 break;455 456 case sizeof(uint32_t):457 SetInteger<uint32_t>(scalar, raw_value, is_signed);458 break;459 460 case sizeof(uint16_t):461 SetInteger<uint16_t>(scalar, raw_value, is_signed);462 break;463 464 case sizeof(uint8_t):465 SetInteger<uint8_t>(scalar, raw_value, is_signed);466 break;467 }468 469 return true;470}471 472static bool SetSizedFloat(Scalar &scalar, uint64_t raw_value,473 uint8_t size_in_bytes) {474 switch (size_in_bytes) {475 default:476 return false;477 478 case sizeof(uint64_t):479 scalar = *reinterpret_cast<double *>(&raw_value);480 break;481 482 case sizeof(uint32_t):483 scalar = *reinterpret_cast<float *>(&raw_value);484 break;485 }486 487 return true;488}489 490static ValueObjectSP GetValObjFromIntRegs(Thread &thread,491 const RegisterContextSP ®_ctx,492 llvm::Triple::ArchType machine,493 uint32_t type_flags,494 uint32_t byte_size) {495 Value value;496 ValueObjectSP return_valobj_sp;497 auto reg_info_a0 =498 reg_ctx->GetRegisterInfo(eRegisterKindGeneric, LLDB_REGNUM_GENERIC_ARG1);499 auto reg_info_a1 =500 reg_ctx->GetRegisterInfo(eRegisterKindGeneric, LLDB_REGNUM_GENERIC_ARG2);501 uint64_t raw_value;502 503 switch (byte_size) {504 case sizeof(uint32_t):505 // Read a0 to get the arg506 raw_value = reg_ctx->ReadRegisterAsUnsigned(reg_info_a0, 0) & UINT32_MAX;507 break;508 case sizeof(uint64_t):509 // Read a0 to get the arg on riscv64, a0 and a1 on riscv32510 if (llvm::Triple::riscv32 == machine) {511 raw_value = reg_ctx->ReadRegisterAsUnsigned(reg_info_a0, 0) & UINT32_MAX;512 raw_value |=513 (reg_ctx->ReadRegisterAsUnsigned(reg_info_a1, 0) & UINT32_MAX) << 32U;514 } else {515 raw_value = reg_ctx->ReadRegisterAsUnsigned(reg_info_a0, 0);516 }517 break;518 case 16: {519 // Read a0 and a1 to get the arg on riscv64, not supported on riscv32520 if (llvm::Triple::riscv32 == machine)521 return return_valobj_sp;522 523 // Create the ValueObjectSP here and return524 std::unique_ptr<DataBufferHeap> heap_data_up(525 new DataBufferHeap(byte_size, 0));526 const ByteOrder byte_order = thread.GetProcess()->GetByteOrder();527 RegisterValue reg_value_a0, reg_value_a1;528 if (reg_ctx->ReadRegister(reg_info_a0, reg_value_a0) &&529 reg_ctx->ReadRegister(reg_info_a1, reg_value_a1)) {530 Status error;531 if (reg_value_a0.GetAsMemoryData(*reg_info_a0,532 heap_data_up->GetBytes() + 0, 8,533 byte_order, error) &&534 reg_value_a1.GetAsMemoryData(*reg_info_a1,535 heap_data_up->GetBytes() + 8, 8,536 byte_order, error)) {537 value.SetBytes(heap_data_up.release(), byte_size);538 return ValueObjectConstResult::Create(539 thread.GetStackFrameAtIndex(0).get(), value, ConstString(""));540 }541 }542 break;543 }544 default:545 return return_valobj_sp;546 }547 548 if (type_flags & eTypeIsInteger) {549 const bool is_signed = (type_flags & eTypeIsSigned) != 0;550 if (!SetSizedInteger(value.GetScalar(), raw_value, byte_size, is_signed))551 return return_valobj_sp;552 } else if (type_flags & eTypeIsFloat) {553 if (!SetSizedFloat(value.GetScalar(), raw_value, byte_size))554 return return_valobj_sp;555 } else556 return return_valobj_sp;557 558 value.SetValueType(Value::ValueType::Scalar);559 return_valobj_sp = ValueObjectConstResult::Create(560 thread.GetStackFrameAtIndex(0).get(), value, ConstString(""));561 return return_valobj_sp;562}563 564static ValueObjectSP565GetValObjFromFPRegs(Thread &thread, const RegisterContextSP ®_ctx,566 llvm::Triple::ArchType machine, uint32_t arch_fp_flags,567 uint32_t type_flags, uint32_t byte_size) {568 auto reg_info_fa0 = reg_ctx->GetRegisterInfoByName("fa0");569 bool use_fp_regs = false;570 ValueObjectSP return_valobj_sp;571 572 switch (arch_fp_flags) {573 // fp return value in integer registers a0 and possibly a1574 case ArchSpec::eRISCV_float_abi_soft:575 return_valobj_sp =576 GetValObjFromIntRegs(thread, reg_ctx, machine, type_flags, byte_size);577 return return_valobj_sp;578 // fp return value in fp register fa0 (only float)579 case ArchSpec::eRISCV_float_abi_single:580 if (byte_size <= 4)581 use_fp_regs = true;582 break;583 // fp return value in fp registers fa0 (float, double)584 case ArchSpec::eRISCV_float_abi_double:585 [[fallthrough]];586 // fp return value in fp registers fa0 (float, double, quad)587 // not implemented; act like they're doubles588 case ArchSpec::eRISCV_float_abi_quad:589 if (byte_size <= 8)590 use_fp_regs = true;591 break;592 }593 594 if (use_fp_regs) {595 uint64_t raw_value;596 Value value;597 raw_value = reg_ctx->ReadRegisterAsUnsigned(reg_info_fa0, 0);598 if (!SetSizedFloat(value.GetScalar(), raw_value, byte_size))599 return return_valobj_sp;600 value.SetValueType(Value::ValueType::Scalar);601 return ValueObjectConstResult::Create(thread.GetStackFrameAtIndex(0).get(),602 value, ConstString(""));603 }604 // we should never reach this, but if we do, use the integer registers605 return GetValObjFromIntRegs(thread, reg_ctx, machine, type_flags, byte_size);606}607 608ValueObjectSP609ABISysV_riscv::GetReturnValueObjectSimple(Thread &thread,610 CompilerType &compiler_type) const {611 ValueObjectSP return_valobj_sp;612 613 if (!compiler_type)614 return return_valobj_sp;615 616 auto reg_ctx = thread.GetRegisterContext();617 if (!reg_ctx)618 return return_valobj_sp;619 620 Value value;621 value.SetCompilerType(compiler_type);622 623 const uint32_t type_flags = compiler_type.GetTypeInfo();624 const size_t byte_size =625 llvm::expectedToOptional(compiler_type.GetByteSize(&thread)).value_or(0);626 const ArchSpec arch = thread.GetProcess()->GetTarget().GetArchitecture();627 const llvm::Triple::ArchType machine = arch.GetMachine();628 629 // Integer return type.630 if (type_flags & eTypeIsInteger) {631 return_valobj_sp =632 GetValObjFromIntRegs(thread, reg_ctx, machine, type_flags, byte_size);633 return return_valobj_sp;634 }635 // Pointer return type.636 else if (type_flags & eTypeIsPointer) {637 auto reg_info_a0 = reg_ctx->GetRegisterInfo(eRegisterKindGeneric,638 LLDB_REGNUM_GENERIC_ARG1);639 value.GetScalar() = reg_ctx->ReadRegisterAsUnsigned(reg_info_a0, 0);640 value.SetValueType(Value::ValueType::Scalar);641 return ValueObjectConstResult::Create(thread.GetStackFrameAtIndex(0).get(),642 value, ConstString(""));643 }644 // Floating point return type.645 else if (type_flags & eTypeIsFloat) {646 bool is_complex = false;647 648 if (compiler_type.IsFloatingPointType(is_complex) &&649 !(type_flags & eTypeIsVector) && !is_complex) {650 const uint32_t arch_fp_flags =651 arch.GetFlags() & ArchSpec::eRISCV_float_abi_mask;652 return_valobj_sp = GetValObjFromFPRegs(653 thread, reg_ctx, machine, arch_fp_flags, type_flags, byte_size);654 return return_valobj_sp;655 }656 }657 // Unsupported return type.658 return return_valobj_sp;659}660 661ValueObjectSP662ABISysV_riscv::GetReturnValueObjectImpl(lldb_private::Thread &thread,663 llvm::Type &type) const {664 Value value;665 ValueObjectSP return_valobj_sp;666 667 auto reg_ctx = thread.GetRegisterContext();668 if (!reg_ctx)669 return return_valobj_sp;670 671 uint32_t type_flags = 0;672 if (type.isIntegerTy())673 type_flags = eTypeIsInteger;674 else if (type.isVoidTy())675 type_flags = eTypeIsPointer;676 else if (type.isFloatTy())677 type_flags = eTypeIsFloat;678 679 const uint32_t byte_size = type.getPrimitiveSizeInBits() / CHAR_BIT;680 const ArchSpec arch = thread.GetProcess()->GetTarget().GetArchitecture();681 const llvm::Triple::ArchType machine = arch.GetMachine();682 683 // Integer return type.684 if (type_flags & eTypeIsInteger) {685 return_valobj_sp =686 GetValObjFromIntRegs(thread, reg_ctx, machine, type_flags, byte_size);687 return return_valobj_sp;688 }689 // Pointer return type.690 else if (type_flags & eTypeIsPointer) {691 auto reg_info_a0 = reg_ctx->GetRegisterInfo(eRegisterKindGeneric,692 LLDB_REGNUM_GENERIC_ARG1);693 value.GetScalar() = reg_ctx->ReadRegisterAsUnsigned(reg_info_a0, 0);694 value.SetValueType(Value::ValueType::Scalar);695 return ValueObjectConstResult::Create(thread.GetStackFrameAtIndex(0).get(),696 value, ConstString(""));697 }698 // Floating point return type.699 else if (type_flags & eTypeIsFloat) {700 const uint32_t arch_fp_flags =701 arch.GetFlags() & ArchSpec::eRISCV_float_abi_mask;702 return_valobj_sp = GetValObjFromFPRegs(703 thread, reg_ctx, machine, arch_fp_flags, type_flags, byte_size);704 return return_valobj_sp;705 }706 // Unsupported return type.707 return return_valobj_sp;708}709 710ValueObjectSP ABISysV_riscv::GetReturnValueObjectImpl(711 Thread &thread, CompilerType &return_compiler_type) const {712 ValueObjectSP return_valobj_sp;713 714 if (!return_compiler_type)715 return return_valobj_sp;716 717 ExecutionContext exe_ctx(thread.shared_from_this());718 return GetReturnValueObjectSimple(thread, return_compiler_type);719}720 721UnwindPlanSP ABISysV_riscv::CreateFunctionEntryUnwindPlan() {722 uint32_t pc_reg_num = riscv_dwarf::dwarf_gpr_pc;723 uint32_t sp_reg_num = riscv_dwarf::dwarf_gpr_sp;724 uint32_t ra_reg_num = riscv_dwarf::dwarf_gpr_ra;725 726 UnwindPlan::Row row;727 728 // Define CFA as the stack pointer729 row.GetCFAValue().SetIsRegisterPlusOffset(sp_reg_num, 0);730 731 // Previous frame's pc is in ra732 row.SetRegisterLocationToRegister(pc_reg_num, ra_reg_num, true);733 734 auto plan_sp = std::make_shared<UnwindPlan>(eRegisterKindDWARF);735 plan_sp->AppendRow(std::move(row));736 plan_sp->SetSourceName("riscv function-entry unwind plan");737 plan_sp->SetSourcedFromCompiler(eLazyBoolNo);738 return plan_sp;739}740 741UnwindPlanSP ABISysV_riscv::CreateDefaultUnwindPlan() {742 uint32_t pc_reg_num = LLDB_REGNUM_GENERIC_PC;743 uint32_t fp_reg_num = LLDB_REGNUM_GENERIC_FP;744 745 UnwindPlan::Row row;746 747 // Define the CFA as the current frame pointer value.748 row.GetCFAValue().SetIsRegisterPlusOffset(fp_reg_num, 0);749 750 int reg_size = 4;751 if (m_is_rv64)752 reg_size = 8;753 754 // Assume the ra reg (return pc) and caller's frame pointer 755 // have been spilled to stack already.756 row.SetRegisterLocationToAtCFAPlusOffset(fp_reg_num, reg_size * -2, true);757 row.SetRegisterLocationToAtCFAPlusOffset(pc_reg_num, reg_size * -1, true);758 759 auto plan_sp = std::make_shared<UnwindPlan>(eRegisterKindGeneric);760 plan_sp->AppendRow(std::move(row));761 plan_sp->SetSourceName("riscv default unwind plan");762 plan_sp->SetSourcedFromCompiler(eLazyBoolNo);763 plan_sp->SetUnwindPlanValidAtAllInstructions(eLazyBoolNo);764 return plan_sp;765}766 767bool ABISysV_riscv::RegisterIsVolatile(const RegisterInfo *reg_info) {768 return !RegisterIsCalleeSaved(reg_info);769}770 771bool ABISysV_riscv::RegisterIsCalleeSaved(const RegisterInfo *reg_info) {772 if (!reg_info)773 return false;774 775 const char *name = reg_info->name;776 ArchSpec arch = GetProcessSP()->GetTarget().GetArchitecture();777 uint32_t arch_flags = arch.GetFlags();778 // floating point registers are only callee saved when using779 // F, D or Q hardware floating point ABIs780 bool is_hw_fp = (arch_flags & ArchSpec::eRISCV_float_abi_mask) != 0;781 782 bool is_callee_saved =783 llvm::StringSwitch<bool>(name)784 // integer ABI names785 .Cases({"ra", "sp", "fp"}, true)786 .Cases({"s0", "s1", "s2", "s3", "s4", "s5", "s6", "s7", "s8", "s9"},787 true)788 .Cases({"s10", "s11"}, true)789 // integer hardware names790 .Cases({"x1", "x2", "x8", "x9", "x18", "x19", "x20", "x21", "x22"},791 true)792 .Cases({"x23", "x24", "x25", "x26", "x27"}, true)793 // floating point ABI names794 .Cases({"fs0", "fs1", "fs2", "fs3", "fs4", "fs5", "fs6", "fs7"},795 is_hw_fp)796 .Cases({"fs8", "fs9", "fs10", "fs11"}, is_hw_fp)797 // floating point hardware names798 .Cases({"f8", "f9", "f18", "f19", "f20", "f21", "f22", "f23"},799 is_hw_fp)800 .Cases({"f24", "f25", "f26", "f27"}, is_hw_fp)801 // vlenb is constant and needed for vector unwinding.802 .Case("vlenb", true)803 .Default(false);804 805 return is_callee_saved;806}807 808void ABISysV_riscv::Initialize() {809 PluginManager::RegisterPlugin(810 GetPluginNameStatic(), "System V ABI for RISCV targets", CreateInstance);811}812 813void ABISysV_riscv::Terminate() {814 PluginManager::UnregisterPlugin(CreateInstance);815}816 817static uint32_t GetGenericNum(llvm::StringRef name) {818 return llvm::StringSwitch<uint32_t>(name)819 .Case("pc", LLDB_REGNUM_GENERIC_PC)820 .Cases({"ra", "x1"}, LLDB_REGNUM_GENERIC_RA)821 .Cases({"sp", "x2"}, LLDB_REGNUM_GENERIC_SP)822 .Cases({"fp", "s0"}, LLDB_REGNUM_GENERIC_FP)823 .Case("a0", LLDB_REGNUM_GENERIC_ARG1)824 .Case("a1", LLDB_REGNUM_GENERIC_ARG2)825 .Case("a2", LLDB_REGNUM_GENERIC_ARG3)826 .Case("a3", LLDB_REGNUM_GENERIC_ARG4)827 .Case("a4", LLDB_REGNUM_GENERIC_ARG5)828 .Case("a5", LLDB_REGNUM_GENERIC_ARG6)829 .Case("a6", LLDB_REGNUM_GENERIC_ARG7)830 .Case("a7", LLDB_REGNUM_GENERIC_ARG8)831 .Default(LLDB_INVALID_REGNUM);832}833 834void ABISysV_riscv::AugmentRegisterInfo(835 std::vector<lldb_private::DynamicRegisterInfo::Register> ®s) {836 lldb_private::RegInfoBasedABI::AugmentRegisterInfo(regs);837 838 for (auto it : llvm::enumerate(regs)) {839 // Set alt name for certain registers for convenience840 if (it.value().name == "zero")841 it.value().alt_name.SetCString("x0");842 else if (it.value().name == "ra")843 it.value().alt_name.SetCString("x1");844 else if (it.value().name == "sp")845 it.value().alt_name.SetCString("x2");846 else if (it.value().name == "gp")847 it.value().alt_name.SetCString("x3");848 else if (it.value().name == "fp")849 it.value().alt_name.SetCString("s0");850 else if (it.value().name == "tp")851 it.value().alt_name.SetCString("x4");852 else if (it.value().name == "s0")853 it.value().alt_name.SetCString("x8");854 else if (it.value().name == "s1")855 it.value().alt_name.SetCString("x9");856 else if (it.value().name == "t0")857 it.value().alt_name.SetCString("x5");858 else if (it.value().name == "t1")859 it.value().alt_name.SetCString("x6");860 else if (it.value().name == "t2")861 it.value().alt_name.SetCString("x7");862 else if (it.value().name == "a0")863 it.value().alt_name.SetCString("x10");864 else if (it.value().name == "a1")865 it.value().alt_name.SetCString("x11");866 else if (it.value().name == "a2")867 it.value().alt_name.SetCString("x12");868 else if (it.value().name == "a3")869 it.value().alt_name.SetCString("x13");870 else if (it.value().name == "a4")871 it.value().alt_name.SetCString("x14");872 else if (it.value().name == "a5")873 it.value().alt_name.SetCString("x15");874 else if (it.value().name == "a6")875 it.value().alt_name.SetCString("x16");876 else if (it.value().name == "a7")877 it.value().alt_name.SetCString("x17");878 else if (it.value().name == "s2")879 it.value().alt_name.SetCString("x18");880 else if (it.value().name == "s3")881 it.value().alt_name.SetCString("x19");882 else if (it.value().name == "s4")883 it.value().alt_name.SetCString("x20");884 else if (it.value().name == "s5")885 it.value().alt_name.SetCString("x21");886 else if (it.value().name == "s6")887 it.value().alt_name.SetCString("x22");888 else if (it.value().name == "s7")889 it.value().alt_name.SetCString("x23");890 else if (it.value().name == "s8")891 it.value().alt_name.SetCString("x24");892 else if (it.value().name == "s9")893 it.value().alt_name.SetCString("x25");894 else if (it.value().name == "s10")895 it.value().alt_name.SetCString("x26");896 else if (it.value().name == "s11")897 it.value().alt_name.SetCString("x27");898 else if (it.value().name == "t3")899 it.value().alt_name.SetCString("x28");900 else if (it.value().name == "t4")901 it.value().alt_name.SetCString("x29");902 else if (it.value().name == "t5")903 it.value().alt_name.SetCString("x30");904 else if (it.value().name == "t6")905 it.value().alt_name.SetCString("x31");906 907 // Set generic regnum so lldb knows what the PC, etc is908 it.value().regnum_generic = GetGenericNum(it.value().name.GetStringRef());909 }910}911