[LLDB] [LoongArch] Add minimal LoongArch support

Add as little code as possible to allow compiling lldb on LoongArch.
Actual functionality will be implemented later.

Reviewed By: SixWeining, DavidSpickett

Differential Revision: https://reviews.llvm.org/D136578

Author: seehearfeel

lldb/source/Plugins/Process/Linux/CMakeLists.txt

@@ -8,6 +8,7 @@ add_lldb_library(lldbPluginProcessLinux
   NativeRegisterContextLinux.cpp
   NativeRegisterContextLinux_arm.cpp
   NativeRegisterContextLinux_arm64.cpp
+  NativeRegisterContextLinux_loongarch64.cpp
   NativeRegisterContextLinux_ppc64le.cpp
   NativeRegisterContextLinux_riscv64.cpp
   NativeRegisterContextLinux_s390x.cpp

lldb/source/Plugins/Process/Linux/NativeRegisterContextLinux_loongarch64.cpp

@@ -0,0 +1,92 @@
+//===-- NativeRegisterContextLinux_loongarch64.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
+//
+//===----------------------------------------------------------------------===//
+
+#if defined(__loongarch__) && __loongarch_grlen == 64
+
+#include "NativeRegisterContextLinux_loongarch64.h"
+
+#include "lldb/Host/HostInfo.h"
+#include "lldb/Utility/DataBufferHeap.h"
+#include "lldb/Utility/Log.h"
+#include "lldb/Utility/RegisterValue.h"
+#include "lldb/Utility/Status.h"
+
+#include "Plugins/Process/Linux/NativeProcessLinux.h"
+#include "Plugins/Process/Linux/Procfs.h"
+
+using namespace lldb;
+using namespace lldb_private;
+using namespace lldb_private::process_linux;
+
+std::unique_ptr<NativeRegisterContextLinux>
+NativeRegisterContextLinux::CreateHostNativeRegisterContextLinux(
+    const ArchSpec &target_arch, NativeThreadLinux &native_thread) {
+  switch (target_arch.GetMachine()) {
+  case llvm::Triple::loongarch64: {
+    Flags opt_regsets;
+    auto register_info_up = std::make_unique<RegisterInfoPOSIX_loongarch64>(
+        target_arch, opt_regsets);
+    return std::make_unique<NativeRegisterContextLinux_loongarch64>(
+        target_arch, native_thread, std::move(register_info_up));
+  }
+  default:
+    llvm_unreachable("have no register context for architecture");
+  }
+}
+
+llvm::Expected<ArchSpec>
+NativeRegisterContextLinux::DetermineArchitecture(lldb::tid_t tid) {
+  return HostInfo::GetArchitecture();
+}
+
+NativeRegisterContextLinux_loongarch64::NativeRegisterContextLinux_loongarch64(
+    const ArchSpec &target_arch, NativeThreadProtocol &native_thread,
+    std::unique_ptr<RegisterInfoPOSIX_loongarch64> register_info_up)
+    : NativeRegisterContextRegisterInfo(native_thread,
+                                        register_info_up.release()),
+      NativeRegisterContextLinux(native_thread) {
+  ::memset(&m_fpr, 0, sizeof(m_fpr));
+  ::memset(&m_gpr, 0, sizeof(m_gpr));
+}
+
+const RegisterInfoPOSIX_loongarch64 &
+NativeRegisterContextLinux_loongarch64::GetRegisterInfo() const {
+  return static_cast<const RegisterInfoPOSIX_loongarch64 &>(
+      NativeRegisterContextRegisterInfo::GetRegisterInfoInterface());
+}
+
+uint32_t NativeRegisterContextLinux_loongarch64::GetRegisterSetCount() const {
+  return GetRegisterInfo().GetRegisterSetCount();
+}
+
+const RegisterSet *NativeRegisterContextLinux_loongarch64::GetRegisterSet(
+    uint32_t set_index) const {
+  return GetRegisterInfo().GetRegisterSet(set_index);
+}
+
+Status NativeRegisterContextLinux_loongarch64::ReadRegister(
+    const RegisterInfo *reg_info, RegisterValue &reg_value) {
+  return Status("Failed to read register value");
+}
+
+Status NativeRegisterContextLinux_loongarch64::WriteRegister(
+    const RegisterInfo *reg_info, const RegisterValue &reg_value) {
+  return Status("Failed to write register value");
+}
+
+Status NativeRegisterContextLinux_loongarch64::ReadAllRegisterValues(
+    lldb::WritableDataBufferSP &data_sp) {
+  return Status("Failed to read all register values");
+}
+
+Status NativeRegisterContextLinux_loongarch64::WriteAllRegisterValues(
+    const lldb::DataBufferSP &data_sp) {
+  return Status("Failed to write all register values");
+}
+
+#endif // defined(__loongarch__) && __loongarch_grlen == 64

lldb/source/Plugins/Process/Linux/NativeRegisterContextLinux_loongarch64.h

@@ -0,0 +1,67 @@
+//===-- NativeRegisterContextLinux_loongarch64.h ----------------*- C++ -*-===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#if defined(__loongarch__) && __loongarch_grlen == 64
+
+#ifndef lldb_NativeRegisterContextLinux_loongarch64_h
+#define lldb_NativeRegisterContextLinux_loongarch64_h
+
+#include "Plugins/Process/Linux/NativeRegisterContextLinux.h"
+#include "Plugins/Process/Utility/RegisterInfoPOSIX_loongarch64.h"
+
+#include <asm/ptrace.h>
+
+namespace lldb_private {
+namespace process_linux {
+
+class NativeProcessLinux;
+
+class NativeRegisterContextLinux_loongarch64
+    : public NativeRegisterContextLinux {
+public:
+  NativeRegisterContextLinux_loongarch64(
+      const ArchSpec &target_arch, NativeThreadProtocol &native_thread,
+      std::unique_ptr<RegisterInfoPOSIX_loongarch64> register_info_up);
+
+  uint32_t GetRegisterSetCount() const override;
+
+  const RegisterSet *GetRegisterSet(uint32_t set_index) const override;
+
+  Status ReadRegister(const RegisterInfo *reg_info,
+                      RegisterValue &reg_value) override;
+
+  Status WriteRegister(const RegisterInfo *reg_info,
+                       const RegisterValue &reg_value) override;
+
+  Status ReadAllRegisterValues(lldb::WritableDataBufferSP &data_sp) override;
+
+  Status WriteAllRegisterValues(const lldb::DataBufferSP &data_sp) override;
+
+protected:
+  void *GetGPRBuffer() override { return &m_gpr; }
+
+  void *GetFPRBuffer() override { return &m_fpr; }
+
+  size_t GetGPRSize() const override { return GetRegisterInfo().GetGPRSize(); }
+
+  size_t GetFPRSize() override { return GetRegisterInfo().GetFPRSize(); }
+
+private:
+  RegisterInfoPOSIX_loongarch64::GPR m_gpr;
+
+  RegisterInfoPOSIX_loongarch64::FPR m_fpr;
+
+  const RegisterInfoPOSIX_loongarch64 &GetRegisterInfo() const;
+};
+
+} // namespace process_linux
+} // namespace lldb_private
+
+#endif // #ifndef lldb_NativeRegisterContextLinux_loongarch64_h
+
+#endif // defined(__loongarch__) && __loongarch_grlen == 64

lldb/source/Plugins/Process/Utility/CMakeLists.txt

@@ -49,6 +49,7 @@ add_lldb_library(lldbPluginProcessUtility
   RegisterContextWindows_x86_64.cpp
   RegisterInfoPOSIX_arm.cpp
   RegisterInfoPOSIX_arm64.cpp
+  RegisterInfoPOSIX_loongarch64.cpp
   RegisterInfoPOSIX_ppc64le.cpp
   RegisterInfoPOSIX_riscv64.cpp
   StopInfoMachException.cpp

lldb/source/Plugins/Process/Utility/RegisterInfoPOSIX_loongarch64.cpp

@@ -0,0 +1,68 @@
+//===-- RegisterInfoPOSIX_loongarch64.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 <cassert>
+#include <lldb/Utility/Flags.h>
+#include <stddef.h>
+
+#include "lldb/lldb-defines.h"
+#include "llvm/Support/Compiler.h"
+
+#include "RegisterInfoPOSIX_loongarch64.h"
+
+const lldb_private::RegisterInfo *
+RegisterInfoPOSIX_loongarch64::GetRegisterInfoPtr(
+    const lldb_private::ArchSpec &target_arch) {
+  switch (target_arch.GetMachine()) {
+  default:
+    assert(false && "Unhandled target architecture.");
+    return nullptr;
+  }
+}
+
+uint32_t RegisterInfoPOSIX_loongarch64::GetRegisterInfoCount(
+    const lldb_private::ArchSpec &target_arch) {
+  switch (target_arch.GetMachine()) {
+  default:
+    assert(false && "Unhandled target architecture.");
+    return 0;
+  }
+}
+
+RegisterInfoPOSIX_loongarch64::RegisterInfoPOSIX_loongarch64(
+    const lldb_private::ArchSpec &target_arch, lldb_private::Flags flags)
+    : lldb_private::RegisterInfoAndSetInterface(target_arch),
+      m_register_info_p(GetRegisterInfoPtr(target_arch)),
+      m_register_info_count(GetRegisterInfoCount(target_arch)) {}
+
+uint32_t RegisterInfoPOSIX_loongarch64::GetRegisterCount() const { return 0; }
+
+size_t RegisterInfoPOSIX_loongarch64::GetGPRSize() const {
+  return sizeof(struct RegisterInfoPOSIX_loongarch64::GPR);
+}
+
+size_t RegisterInfoPOSIX_loongarch64::GetFPRSize() const {
+  return sizeof(struct RegisterInfoPOSIX_loongarch64::FPR);
+}
+
+const lldb_private::RegisterInfo *
+RegisterInfoPOSIX_loongarch64::GetRegisterInfo() const {
+  return m_register_info_p;
+}
+
+size_t RegisterInfoPOSIX_loongarch64::GetRegisterSetCount() const { return 0; }
+
+size_t RegisterInfoPOSIX_loongarch64::GetRegisterSetFromRegisterIndex(
+    uint32_t reg_index) const {
+  return LLDB_INVALID_REGNUM;
+}
+
+const lldb_private::RegisterSet *
+RegisterInfoPOSIX_loongarch64::GetRegisterSet(size_t set_index) const {
+  return nullptr;
+}

lldb/source/Plugins/Process/Utility/RegisterInfoPOSIX_loongarch64.h

@@ -0,0 +1,64 @@
+//===-- RegisterInfoPOSIX_loongarch64.h -------------------------*- C++ -*-===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLDB_SOURCE_PLUGINS_PROCESS_UTILITY_REGISTERINFOPOSIX_LOONGARCH64_H
+#define LLDB_SOURCE_PLUGINS_PROCESS_UTILITY_REGISTERINFOPOSIX_LOONGARCH64_H
+
+#include "RegisterInfoAndSetInterface.h"
+#include "lldb/Target/RegisterContext.h"
+#include "lldb/lldb-private.h"
+#include <map>
+
+class RegisterInfoPOSIX_loongarch64
+    : public lldb_private::RegisterInfoAndSetInterface {
+public:
+  static const lldb_private::RegisterInfo *
+  GetRegisterInfoPtr(const lldb_private::ArchSpec &target_arch);
+  static uint32_t
+  GetRegisterInfoCount(const lldb_private::ArchSpec &target_arch);
+
+public:
+  struct GPR {
+    uint64_t gpr[32];
+
+    uint64_t orig_a0;
+    uint64_t csr_era;
+    uint64_t csr_badv;
+    uint64_t reserved[10];
+  };
+
+  struct FPR {
+    uint64_t fpr[32];
+    uint64_t fcc;
+    uint32_t fcsr;
+  };
+
+  RegisterInfoPOSIX_loongarch64(const lldb_private::ArchSpec &target_arch,
+                                lldb_private::Flags flags);
+
+  size_t GetGPRSize() const override;
+
+  size_t GetFPRSize() const override;
+
+  const lldb_private::RegisterInfo *GetRegisterInfo() const override;
+
+  uint32_t GetRegisterCount() const override;
+
+  const lldb_private::RegisterSet *
+  GetRegisterSet(size_t reg_set) const override;
+
+  size_t GetRegisterSetCount() const override;
+
+  size_t GetRegisterSetFromRegisterIndex(uint32_t reg_index) const override;
+
+private:
+  const lldb_private::RegisterInfo *m_register_info_p;
+  uint32_t m_register_info_count;
+};
+
+#endif