[llvm-branch-commits] [lldb] [lldb][LoongArch] Function calls support in lldb expressions (PR #114742)
David Spickett via llvm-branch-commits
llvm-branch-commits at lists.llvm.org
Mon Nov 4 02:22:07 PST 2024
================
@@ -0,0 +1,664 @@
+//===-- ABISysV_loongarch.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 "ABISysV_loongarch.h"
+
+#include <array>
+#include <limits>
+#include <sstream>
+
+#include "llvm/IR/DerivedTypes.h"
+
+#include "Utility/LoongArch_DWARF_Registers.h"
+#include "lldb/Core/PluginManager.h"
+#include "lldb/Core/Value.h"
+#include "lldb/Target/RegisterContext.h"
+#include "lldb/Target/StackFrame.h"
+#include "lldb/Target/Thread.h"
+#include "lldb/Utility/LLDBLog.h"
+#include "lldb/Utility/RegisterValue.h"
+#include "lldb/ValueObject/ValueObjectConstResult.h"
+
+#define DEFINE_REG_NAME(reg_num) ConstString(#reg_num).GetCString()
+#define DEFINE_REG_NAME_STR(reg_name) ConstString(reg_name).GetCString()
+
+// The ABI is not a source of such information as size, offset, encoding, etc.
+// of a register. Just provides correct dwarf and eh_frame numbers.
+
+#define DEFINE_GENERIC_REGISTER_STUB(dwarf_num, str_name, generic_num) \
+ { \
+ DEFINE_REG_NAME(dwarf_num), \
+ DEFINE_REG_NAME_STR(str_name), \
+ 0, \
+ 0, \
+ eEncodingInvalid, \
+ eFormatDefault, \
+ {dwarf_num, dwarf_num, generic_num, LLDB_INVALID_REGNUM, dwarf_num}, \
+ nullptr, \
+ nullptr, \
+ nullptr, \
+ }
+
+#define DEFINE_REGISTER_STUB(dwarf_num, str_name) \
+ DEFINE_GENERIC_REGISTER_STUB(dwarf_num, str_name, LLDB_INVALID_REGNUM)
+
+using namespace lldb;
+using namespace lldb_private;
+
+LLDB_PLUGIN_DEFINE_ADV(ABISysV_loongarch, ABILoongArch)
+
+namespace {
+namespace dwarf {
+enum regnums {
+ r0,
+ ra,
+ r1 = ra,
+ r2,
+ sp,
+ r3 = sp,
+ r4,
+ r5,
+ r6,
+ r7,
+ r8,
+ r9,
+ r10,
+ r11,
+ r12,
+ r13,
+ r14,
+ r15,
+ r16,
+ r17,
+ r18,
+ r19,
+ r20,
+ r21,
+ fp,
+ r22 = fp,
+ r23,
+ r24,
+ r25,
+ r26,
+ r27,
+ r28,
+ r29,
+ r30,
+ r31,
+ pc
+};
+
+static const std::array<RegisterInfo, 33> g_register_infos = {
+ {DEFINE_REGISTER_STUB(r0, nullptr),
+ DEFINE_GENERIC_REGISTER_STUB(r1, nullptr, LLDB_REGNUM_GENERIC_RA),
+ DEFINE_REGISTER_STUB(r2, nullptr),
+ DEFINE_GENERIC_REGISTER_STUB(r3, nullptr, LLDB_REGNUM_GENERIC_SP),
+ DEFINE_GENERIC_REGISTER_STUB(r4, nullptr, LLDB_REGNUM_GENERIC_ARG1),
+ DEFINE_GENERIC_REGISTER_STUB(r5, nullptr, LLDB_REGNUM_GENERIC_ARG2),
+ DEFINE_GENERIC_REGISTER_STUB(r6, nullptr, LLDB_REGNUM_GENERIC_ARG3),
+ DEFINE_GENERIC_REGISTER_STUB(r7, nullptr, LLDB_REGNUM_GENERIC_ARG4),
+ DEFINE_GENERIC_REGISTER_STUB(r8, nullptr, LLDB_REGNUM_GENERIC_ARG5),
+ DEFINE_GENERIC_REGISTER_STUB(r9, nullptr, LLDB_REGNUM_GENERIC_ARG6),
+ DEFINE_GENERIC_REGISTER_STUB(r10, nullptr, LLDB_REGNUM_GENERIC_ARG7),
+ DEFINE_GENERIC_REGISTER_STUB(r11, nullptr, LLDB_REGNUM_GENERIC_ARG8),
+ DEFINE_REGISTER_STUB(r12, nullptr),
+ DEFINE_REGISTER_STUB(r13, nullptr),
+ DEFINE_REGISTER_STUB(r14, nullptr),
+ DEFINE_REGISTER_STUB(r15, nullptr),
+ DEFINE_REGISTER_STUB(r16, nullptr),
+ DEFINE_REGISTER_STUB(r17, nullptr),
+ DEFINE_REGISTER_STUB(r18, nullptr),
+ DEFINE_REGISTER_STUB(r19, nullptr),
+ DEFINE_REGISTER_STUB(r20, nullptr),
+ DEFINE_REGISTER_STUB(r21, nullptr),
+ DEFINE_GENERIC_REGISTER_STUB(r22, nullptr, LLDB_REGNUM_GENERIC_FP),
+ DEFINE_REGISTER_STUB(r23, nullptr),
+ DEFINE_REGISTER_STUB(r24, nullptr),
+ DEFINE_REGISTER_STUB(r25, nullptr),
+ DEFINE_REGISTER_STUB(r26, nullptr),
+ DEFINE_REGISTER_STUB(r27, nullptr),
+ DEFINE_REGISTER_STUB(r28, nullptr),
+ DEFINE_REGISTER_STUB(r29, nullptr),
+ DEFINE_REGISTER_STUB(r30, nullptr),
+ DEFINE_REGISTER_STUB(r31, nullptr),
+ DEFINE_GENERIC_REGISTER_STUB(pc, nullptr, LLDB_REGNUM_GENERIC_PC)}};
+} // namespace dwarf
+} // namespace
+
+// Number of argument registers (the base integer calling convention
+// provides 8 argument registers, a0-a7)
+static constexpr size_t g_regs_for_args_count = 8U;
+
+const RegisterInfo *ABISysV_loongarch::GetRegisterInfoArray(uint32_t &count) {
+ count = dwarf::g_register_infos.size();
+ return dwarf::g_register_infos.data();
+}
+
+//------------------------------------------------------------------
+// Static Functions
+//------------------------------------------------------------------
+
+ABISP
+ABISysV_loongarch::CreateInstance(ProcessSP process_sp, const ArchSpec &arch) {
+ llvm::Triple::ArchType machine = arch.GetTriple().getArch();
+
+ if (llvm::Triple::loongarch32 != machine &&
+ llvm::Triple::loongarch64 != machine)
+ return ABISP();
+
+ ABISysV_loongarch *abi =
+ new ABISysV_loongarch(std::move(process_sp), MakeMCRegisterInfo(arch));
+ if (abi)
+ abi->SetIsLA64((llvm::Triple::loongarch64 == machine) ? true : false);
+ return ABISP(abi);
+}
+
+static bool UpdateRegister(RegisterContext *reg_ctx,
+ const lldb::RegisterKind reg_kind,
+ const uint32_t reg_num, const addr_t value) {
+ Log *log = GetLog(LLDBLog::Expressions);
+
+ const RegisterInfo *reg_info = reg_ctx->GetRegisterInfo(reg_kind, reg_num);
+
+ LLDB_LOG(log, "Writing {0}: 0x{1:x}", reg_info->name,
+ static_cast<uint64_t>(value));
+ if (!reg_ctx->WriteRegisterFromUnsigned(reg_info, value)) {
+ LLDB_LOG(log, "Writing {0}: failed", reg_info->name);
+ return false;
+ }
+ return true;
+}
+
+static void LogInitInfo(Log &log, const Thread &thread, addr_t sp,
+ addr_t func_addr, addr_t return_addr,
+ const llvm::ArrayRef<addr_t> args) {
+ std::stringstream ss;
+ ss << "ABISysV_loongarch::PrepareTrivialCall"
+ << " (tid = 0x" << std::hex << thread.GetID() << ", sp = 0x" << sp
+ << ", func_addr = 0x" << func_addr << ", return_addr = 0x" << return_addr;
+
+ for (auto [idx, arg] : enumerate(args))
+ ss << ", arg" << std::dec << idx << " = 0x" << std::hex << arg;
+ ss << ")";
+ log.PutString(ss.str());
+}
+
+bool ABISysV_loongarch::PrepareTrivialCall(Thread &thread, addr_t sp,
+ addr_t func_addr, addr_t return_addr,
+ llvm::ArrayRef<addr_t> args) const {
+ Log *log = GetLog(LLDBLog::Expressions);
+ if (log)
+ LogInitInfo(*log, thread, sp, func_addr, return_addr, args);
+
+ const auto reg_ctx_sp = thread.GetRegisterContext();
+ if (!reg_ctx_sp) {
+ LLDB_LOG(log, "Failed to get RegisterContext");
+ return false;
+ }
+
+ if (args.size() > g_regs_for_args_count) {
+ LLDB_LOG(log, "Function has {0} arguments, but only {1} are allowed!",
+ args.size(), g_regs_for_args_count);
+ return false;
+ }
+
+ // Write arguments to registers
+ for (auto [idx, arg] : enumerate(args)) {
+ const RegisterInfo *reg_info = reg_ctx_sp->GetRegisterInfo(
+ eRegisterKindGeneric, LLDB_REGNUM_GENERIC_ARG1 + idx);
+ LLDB_LOG(log, "About to write arg{0} (0x{1:x}) into {2}", idx, arg,
+ reg_info->name);
+
+ if (!reg_ctx_sp->WriteRegisterFromUnsigned(reg_info, arg)) {
+ LLDB_LOG(log, "Failed to write arg{0} (0x{1:x}) into {2}", idx, arg,
+ reg_info->name);
+ return false;
+ }
+ }
+
+ if (!UpdateRegister(reg_ctx_sp.get(), eRegisterKindGeneric,
+ LLDB_REGNUM_GENERIC_PC, func_addr))
+ return false;
+ if (!UpdateRegister(reg_ctx_sp.get(), eRegisterKindGeneric,
+ LLDB_REGNUM_GENERIC_SP, sp))
+ return false;
+ if (!UpdateRegister(reg_ctx_sp.get(), eRegisterKindGeneric,
+ LLDB_REGNUM_GENERIC_RA, return_addr))
+ return false;
+
+ LLDB_LOG(log, "ABISysV_riscv::{0}() success", __FUNCTION__);
+ return true;
+}
+
+bool ABISysV_loongarch::GetArgumentValues(Thread &thread,
+ ValueList &values) const {
+ // TODO: Implement
+ return false;
+}
+
+Status ABISysV_loongarch::SetReturnValueObject(StackFrameSP &frame_sp,
+ ValueObjectSP &new_value_sp) {
+ Status result;
+ if (!new_value_sp) {
+ result = Status::FromErrorString("Empty value object for return value.");
+ return result;
+ }
+
+ CompilerType compiler_type = new_value_sp->GetCompilerType();
+ if (!compiler_type) {
+ result = Status::FromErrorString("Null clang type for return value.");
+ return result;
+ }
+
+ auto ®_ctx = *frame_sp->GetThread()->GetRegisterContext();
+
+ bool is_signed = false;
+ if (!compiler_type.IsIntegerOrEnumerationType(is_signed) &&
+ !compiler_type.IsPointerType()) {
+ result = Status::FromErrorString(
+ "We don't support returning other types at present");
+ return result;
+ }
+
+ DataExtractor data;
+ size_t num_bytes = new_value_sp->GetData(data, result);
+
+ if (result.Fail()) {
+ result = Status::FromErrorStringWithFormat(
+ "Couldn't convert return value to raw data: %s", result.AsCString());
+ return result;
+ }
+
+ size_t reg_size = m_is_la64 ? 8 : 4;
+ if (num_bytes <= 2 * reg_size) {
+ offset_t offset = 0;
+ uint64_t raw_value = data.GetMaxU64(&offset, num_bytes);
+
+ auto reg_info =
+ reg_ctx.GetRegisterInfo(eRegisterKindGeneric, LLDB_REGNUM_GENERIC_ARG1);
+ if (!reg_ctx.WriteRegisterFromUnsigned(reg_info, raw_value)) {
+ result = Status::FromErrorStringWithFormat(
+ "Couldn't write value to register %s", reg_info->name);
+ return result;
+ }
+
+ if (num_bytes <= reg_size)
+ return result; // Successfully written.
+
+ // for loongarch32, get the upper 32 bits from raw_value and write them
+ // for loongarch64, get the next 64 bits from data and write them
+ if (4 == reg_size)
+ raw_value >>= 32;
+ else
+ raw_value = data.GetMaxU64(&offset, num_bytes - reg_size);
+ reg_info =
+ reg_ctx.GetRegisterInfo(eRegisterKindGeneric, LLDB_REGNUM_GENERIC_ARG2);
+ if (!reg_ctx.WriteRegisterFromUnsigned(reg_info, raw_value)) {
+ result = Status::FromErrorStringWithFormat(
+ "Couldn't write value to register %s", reg_info->name);
+ }
+
+ return result;
+ }
+
+ result = Status::FromErrorString(
+ "We don't support returning large integer values at present.");
+ return result;
+}
+
+template <typename T>
+static void SetInteger(Scalar &scalar, uint64_t raw_value, bool is_signed) {
+ raw_value &= std::numeric_limits<T>::max();
+ if (is_signed)
+ scalar = static_cast<typename std::make_signed<T>::type>(raw_value);
+ else
+ scalar = static_cast<T>(raw_value);
+}
+
+static bool SetSizedInteger(Scalar &scalar, uint64_t raw_value,
+ uint8_t size_in_bytes, bool is_signed) {
+ switch (size_in_bytes) {
+ default:
+ return false;
+
+ case sizeof(uint64_t):
+ SetInteger<uint64_t>(scalar, raw_value, is_signed);
+ break;
+
+ case sizeof(uint32_t):
+ SetInteger<uint32_t>(scalar, raw_value, is_signed);
+ break;
+
+ case sizeof(uint16_t):
+ SetInteger<uint16_t>(scalar, raw_value, is_signed);
+ break;
+
+ case sizeof(uint8_t):
+ SetInteger<uint8_t>(scalar, raw_value, is_signed);
+ break;
+ }
+
+ return true;
+}
+
+static bool SetSizedFloat(Scalar &scalar, uint64_t raw_value,
+ uint8_t size_in_bytes) {
+ switch (size_in_bytes) {
+ default:
+ return false;
+
+ case sizeof(uint64_t):
+ scalar = *reinterpret_cast<double *>(&raw_value);
+ break;
+
+ case sizeof(uint32_t):
+ scalar = *reinterpret_cast<float *>(&raw_value);
+ break;
+ }
+
+ return true;
+}
+
+static ValueObjectSP GetValObjFromIntRegs(Thread &thread,
+ const RegisterContextSP ®_ctx,
+ llvm::Triple::ArchType machine,
+ uint32_t type_flags,
+ uint32_t byte_size) {
+ Value value;
+ ValueObjectSP return_valobj_sp;
+ auto reg_info_a0 =
+ reg_ctx->GetRegisterInfo(eRegisterKindGeneric, LLDB_REGNUM_GENERIC_ARG1);
+ auto reg_info_a1 =
+ reg_ctx->GetRegisterInfo(eRegisterKindGeneric, LLDB_REGNUM_GENERIC_ARG2);
+ uint64_t raw_value;
+
+ switch (byte_size) {
+ case sizeof(uint32_t):
+ // Read a0 to get the arg
+ raw_value = reg_ctx->ReadRegisterAsUnsigned(reg_info_a0, 0) & UINT32_MAX;
+ break;
+ case sizeof(uint64_t):
+ raw_value = reg_ctx->ReadRegisterAsUnsigned(reg_info_a0, 0);
+ break;
+ case 16: {
+ // Create the ValueObjectSP here and return
+ std::unique_ptr<DataBufferHeap> heap_data_up(
+ new DataBufferHeap(byte_size, 0));
+ const ByteOrder byte_order = thread.GetProcess()->GetByteOrder();
+ RegisterValue reg_value_a0, reg_value_a1;
+ if (reg_ctx->ReadRegister(reg_info_a0, reg_value_a0) &&
+ reg_ctx->ReadRegister(reg_info_a1, reg_value_a1)) {
+ Status error;
+ if (reg_value_a0.GetAsMemoryData(*reg_info_a0,
+ heap_data_up->GetBytes() + 0, 8,
+ byte_order, error) &&
+ reg_value_a1.GetAsMemoryData(*reg_info_a1,
+ heap_data_up->GetBytes() + 8, 8,
+ byte_order, error)) {
+ value.SetBytes(heap_data_up.release(), byte_size);
+ return ValueObjectConstResult::Create(
+ thread.GetStackFrameAtIndex(0).get(), value, ConstString(""));
+ }
+ }
+ break;
+ }
+ default:
+ return return_valobj_sp;
+ }
+
+ if (type_flags & eTypeIsInteger) {
+ const bool is_signed = (type_flags & eTypeIsSigned) != 0;
+ if (!SetSizedInteger(value.GetScalar(), raw_value, byte_size, is_signed))
+ return return_valobj_sp;
+ } else if (type_flags & eTypeIsFloat) {
+ if (!SetSizedFloat(value.GetScalar(), raw_value, byte_size))
+ return return_valobj_sp;
+ } else
+ return return_valobj_sp;
+
+ value.SetValueType(Value::ValueType::Scalar);
+ return_valobj_sp = ValueObjectConstResult::Create(
+ thread.GetStackFrameAtIndex(0).get(), value, ConstString(""));
+ return return_valobj_sp;
+}
+
+static ValueObjectSP GetValObjFromFPRegs(Thread &thread,
+ const RegisterContextSP ®_ctx,
+ llvm::Triple::ArchType machine,
+ uint32_t type_flags,
+ uint32_t byte_size) {
+ auto reg_info_fa0 = reg_ctx->GetRegisterInfoByName("f0");
+ bool use_fp_regs = false;
+ ValueObjectSP return_valobj_sp;
+
+ if (byte_size <= 8)
+ use_fp_regs = true;
+
+ if (use_fp_regs) {
+ uint64_t raw_value;
+ Value value;
+ raw_value = reg_ctx->ReadRegisterAsUnsigned(reg_info_fa0, 0);
+ if (!SetSizedFloat(value.GetScalar(), raw_value, byte_size))
+ return return_valobj_sp;
+ value.SetValueType(Value::ValueType::Scalar);
+ return ValueObjectConstResult::Create(thread.GetStackFrameAtIndex(0).get(),
+ value, ConstString(""));
+ }
+ // we should never reach this, but if we do, use the integer registers
+ return GetValObjFromIntRegs(thread, reg_ctx, machine, type_flags, byte_size);
+}
+
+ValueObjectSP ABISysV_loongarch::GetReturnValueObjectSimple(
+ Thread &thread, CompilerType &compiler_type) const {
+ ValueObjectSP return_valobj_sp;
+
+ if (!compiler_type)
+ return return_valobj_sp;
+
+ auto reg_ctx = thread.GetRegisterContext();
+ if (!reg_ctx)
+ return return_valobj_sp;
+
+ Value value;
+ value.SetCompilerType(compiler_type);
+
+ const uint32_t type_flags = compiler_type.GetTypeInfo();
+ const size_t byte_size = compiler_type.GetByteSize(&thread).value_or(0);
+ const ArchSpec arch = thread.GetProcess()->GetTarget().GetArchitecture();
+ const llvm::Triple::ArchType machine = arch.GetMachine();
+
+ // Integer return type.
----------------
DavidSpickett wrote:
These comments are redundant, it's clear from the `if (...` what the next block is doing.
https://github.com/llvm/llvm-project/pull/114742
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