src/third_party/llvm-project/lldb/source/Plugins/ABI/SysV-i386/ABISysV_i386.h

//===------------------- ABISysV_i386.h -------------------------*- C++ -*-===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//

#ifndef liblldb_ABISysV_i386_h_
#define liblldb_ABISysV_i386_h_

// C Includes
// C++ Includes
// Other libraries and framework includes
// Project includes
#include "lldb/Target/ABI.h"
#include "lldb/lldb-private.h"

class ABISysV_i386 : public lldb_private::ABI {
public:
  ~ABISysV_i386() override = default;

  size_t GetRedZoneSize() const override {
    return 0; // There is no red zone for i386 Architecture
  }

  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 {
    return !RegisterIsCalleeSaved(reg_info);
  }

  // The SysV i386 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
  // (4-bytes).
  // Whitelisting 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.

  // ToDo: When __m256 arguments are passed then stack frames should be
  // 32 byte aligned. Decide what to do for 32 byte alignment checking
  bool CallFrameAddressIsValid(lldb::addr_t cfa) override {
    // Make sure the stack call frame addresses are 4 byte aligned
    if (cfa & (4ull - 1ull))
      return false; // Not 4 byte aligned
    if (cfa == 0)
      return false; // Zero is not a valid stack address
    return true;
  }

  bool CodeAddressIsValid(lldb::addr_t pc) override {
    // Check whether the address is a valid 32 bit address
    return (pc <= UINT32_MAX);
  }

  const lldb_private::RegisterInfo *
  GetRegisterInfoArray(uint32_t &count) override;

  //------------------------------------------------------------------
  // Static Functions
  //------------------------------------------------------------------

  static void Initialize();

  static void Terminate();

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

  //------------------------------------------------------------------
  // PluginInterface protocol
  //------------------------------------------------------------------

  static lldb_private::ConstString GetPluginNameStatic();

  lldb_private::ConstString GetPluginName() override;

  uint32_t GetPluginVersion() override { return 1; }

protected:
  lldb::ValueObjectSP
  GetReturnValueObjectSimple(lldb_private::Thread &thread,
                             lldb_private::CompilerType &ast_type) const;

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

private:
  ABISysV_i386(lldb::ProcessSP process_sp) : lldb_private::ABI(process_sp) {
    // Call CreateInstance instead.
  }
};

#endif // liblldb_ABISysV_i386_h_