//===-- ABISysV_x86_64.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_ABI_X86_ABISYSV_X86_64_H

#define LLDB_SOURCE_PLUGINS_ABI_X86_ABISYSV_X86_64_H

#include "Plugins/ABI/X86/ABIX86_64.h"

class ABISysV_x86_64 : public ABIX86_64 {

public:

  ~ABISysV_x86_64() override = default;

  size_t GetRedZoneSize() const override;

  bool PrepareTrivialCall(lldb_private::Thread &thread, lldb::addr_t sp,

                          lldb::addr_t functionAddress,

                          lldb::addr_t returnAddress,

                          llvm::ArrayRef<lldb::addr_t> args) const override;

  bool GetArgumentValues(lldb_private::Thread &thread,

                         lldb_private::ValueList &values) const override;

  lldb_private::Status

  SetReturnValueObject(lldb::StackFrameSP &frame_sp,

                       lldb::ValueObjectSP &new_value) override;

  lldb::ValueObjectSP

  GetReturnValueObjectImpl(lldb_private::Thread &thread,

                           lldb_private::CompilerType &type) const override;

  bool

  CreateFunctionEntryUnwindPlan(lldb_private::UnwindPlan &unwind_plan) override;

  bool CreateDefaultUnwindPlan(lldb_private::UnwindPlan &unwind_plan) override;

  bool RegisterIsVolatile(const lldb_private::RegisterInfo *reg_info) override;

  // The SysV x86_64 ABI requires that stack frames be 16 byte aligned.

  // When there is a trap handler on the stack, e.g. _sigtramp in userland

  // code, we've seen that the stack pointer is often not aligned properly

  // before the handler is invoked.  This means that lldb will stop the unwind

  // early -- before the function which caused the trap.

  //

  // To work around this, we relax that alignment to be just word-size

  // (8-bytes).

  // Allowing the trap handlers for user space would be easy (_sigtramp) but

  // in other environments there can be a large number of different functions

  // involved in async traps.

  bool CallFrameAddressIsValid(lldb::addr_t cfa) override {

    // Make sure the stack call frame addresses are 8 byte aligned

    if (cfa & (8ull - 1ull))

      return false; // Not 8 byte aligned

    if (cfa == 0)

      return false; // Zero is not a valid stack address

    return true;

  }

  bool CodeAddressIsValid(lldb::addr_t pc) override {

    // We have a 64 bit address space, so anything is valid as opcodes

    // aren't fixed width...

    return true;

  }

  bool GetPointerReturnRegister(const char *&name) override;

  // Static Functions

  static void Initialize();

  static void Terminate();

  static lldb::ABISP CreateInstance(lldb::ProcessSP process_sp, const lldb_private::ArchSpec &arch);

  static llvm::StringRef GetPluginNameStatic() { return "sysv-x86_64"; }

  // PluginInterface protocol

  llvm::StringRef GetPluginName() override { return GetPluginNameStatic(); }

protected:

  void CreateRegisterMapIfNeeded();

  lldb::ValueObjectSP

  GetReturnValueObjectSimple(lldb_private::Thread &thread,

                             lldb_private::CompilerType &ast_type) const;

  bool RegisterIsCalleeSaved(const lldb_private::RegisterInfo *reg_info);

  uint32_t GetGenericNum(llvm::StringRef reg) override;

private:

  using ABIX86_64::ABIX86_64; // Call CreateInstance instead.

};

#endif // LLDB_SOURCE_PLUGINS_ABI_X86_ABISYSV_X86_64_H