blob: 392b462ecf072beb0498c3ec8cc754c92aaa3082 [file] [log] [blame]
//===-- RegisterContext.h ---------------------------------------*- C++ -*-===//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
#include "lldb/Target/ExecutionContextScope.h"
#include "lldb/lldb-private.h"
namespace lldb_private {
class RegisterContext : public std::enable_shared_from_this<RegisterContext>,
public ExecutionContextScope {
// Constructors and Destructors
RegisterContext(Thread &thread, uint32_t concrete_frame_idx);
~RegisterContext() override;
void InvalidateIfNeeded(bool force);
// Subclasses must override these functions
virtual void InvalidateAllRegisters() = 0;
virtual size_t GetRegisterCount() = 0;
virtual const RegisterInfo *GetRegisterInfoAtIndex(size_t reg) = 0;
virtual size_t GetRegisterSetCount() = 0;
virtual const RegisterSet *GetRegisterSet(size_t reg_set) = 0;
virtual lldb::ByteOrder GetByteOrder();
virtual bool ReadRegister(const RegisterInfo *reg_info,
RegisterValue &reg_value) = 0;
virtual bool WriteRegister(const RegisterInfo *reg_info,
const RegisterValue &reg_value) = 0;
virtual bool ReadAllRegisterValues(lldb::DataBufferSP &data_sp) {
return false;
virtual bool WriteAllRegisterValues(const lldb::DataBufferSP &data_sp) {
return false;
// These two functions are used to implement "push" and "pop" of register
// states. They are used primarily for expression evaluation, where we need
// to push a new state (storing the old one in data_sp) and then restoring
// the original state by passing the data_sp we got from ReadAllRegisters to
// WriteAllRegisterValues. ReadAllRegisters will do what is necessary to
// return a coherent set of register values for this thread, which may mean
// e.g. interrupting a thread that is sitting in a kernel trap. That is a
// somewhat disruptive operation, so these API's should only be used when
// this behavior is needed.
virtual bool
ReadAllRegisterValues(lldb_private::RegisterCheckpoint &reg_checkpoint);
virtual bool WriteAllRegisterValues(
const lldb_private::RegisterCheckpoint &reg_checkpoint);
bool CopyFromRegisterContext(lldb::RegisterContextSP context);
/// Convert from a given register numbering scheme to the lldb register
/// numbering scheme
/// There may be multiple ways to enumerate the registers for a given
/// architecture. ABI references will specify one to be used with
/// DWARF, the register numberings from process plugin, there may
/// be a variation used for eh_frame unwind instructions (e.g. on Darwin),
/// and so on. Register 5 by itself is meaningless - RegisterKind
/// enumeration tells you what context that number should be translated as.
/// Inside lldb, register numbers are in the eRegisterKindLLDB scheme;
/// arguments which take a register number should take one in that
/// scheme.
/// eRegisterKindGeneric is a special numbering scheme which gives us
/// constant values for the pc, frame register, stack register, etc., for
/// use within lldb. They may not be defined for all architectures but
/// it allows generic code to translate these common registers into the
/// lldb numbering scheme.
/// This method translates a given register kind + register number into
/// the eRegisterKindLLDB register numbering.
/// \param [in] kind
/// The register numbering scheme (RegisterKind) that the following
/// register number is in.
/// \param [in] num
/// A register number in the 'kind' register numbering scheme.
/// \return
/// The equivalent register number in the eRegisterKindLLDB
/// numbering scheme, if possible, else LLDB_INVALID_REGNUM.
virtual uint32_t ConvertRegisterKindToRegisterNumber(lldb::RegisterKind kind,
uint32_t num);
// Subclasses can override these functions if desired
virtual uint32_t NumSupportedHardwareBreakpoints();
virtual uint32_t SetHardwareBreakpoint(lldb::addr_t addr, size_t size);
virtual bool ClearHardwareBreakpoint(uint32_t hw_idx);
virtual uint32_t NumSupportedHardwareWatchpoints();
virtual uint32_t SetHardwareWatchpoint(lldb::addr_t addr, size_t size,
bool read, bool write);
virtual bool ClearHardwareWatchpoint(uint32_t hw_index);
virtual bool HardwareSingleStep(bool enable);
virtual Status
ReadRegisterValueFromMemory(const lldb_private::RegisterInfo *reg_info,
lldb::addr_t src_addr, uint32_t src_len,
RegisterValue &reg_value);
virtual Status
WriteRegisterValueToMemory(const lldb_private::RegisterInfo *reg_info,
lldb::addr_t dst_addr, uint32_t dst_len,
const RegisterValue &reg_value);
// Subclasses should not override these
virtual lldb::tid_t GetThreadID() const;
virtual Thread &GetThread() { return m_thread; }
const RegisterInfo *GetRegisterInfoByName(llvm::StringRef reg_name,
uint32_t start_idx = 0);
const RegisterInfo *GetRegisterInfo(lldb::RegisterKind reg_kind,
uint32_t reg_num);
uint64_t GetPC(uint64_t fail_value = LLDB_INVALID_ADDRESS);
/// Get an address suitable for symbolication.
/// When symbolicating -- computing line, block, function --
/// for a function in the middle of the stack, using the return
/// address can lead to unexpected results for the user.
/// A function that ends in a tail-call may have another function
/// as the "return" address, but it will never actually return.
/// Or a noreturn call in the middle of a function is the end of
/// a block of instructions, and a DWARF location list entry for
/// the return address may be a very different code path with
/// incorrect results when printing variables for this frame.
/// At a source line view, the user expects the current-line indictation
/// to point to the function call they're under, not the next source line.
/// The return address (GetPC()) should always be shown to the user,
/// but when computing context, keeping within the bounds of the
/// call instruction is what the user expects to see.
/// \param [out] address
/// An Address object that will be filled in, if a PC can be retrieved.
/// \return
/// Returns true if the Address param was filled in.
bool GetPCForSymbolication(Address &address);
bool SetPC(uint64_t pc);
bool SetPC(Address addr);
uint64_t GetSP(uint64_t fail_value = LLDB_INVALID_ADDRESS);
bool SetSP(uint64_t sp);
uint64_t GetFP(uint64_t fail_value = LLDB_INVALID_ADDRESS);
bool SetFP(uint64_t fp);
const char *GetRegisterName(uint32_t reg);
uint64_t GetReturnAddress(uint64_t fail_value = LLDB_INVALID_ADDRESS);
uint64_t GetFlags(uint64_t fail_value = 0);
uint64_t ReadRegisterAsUnsigned(uint32_t reg, uint64_t fail_value);
uint64_t ReadRegisterAsUnsigned(const RegisterInfo *reg_info,
uint64_t fail_value);
bool WriteRegisterFromUnsigned(uint32_t reg, uint64_t uval);
bool WriteRegisterFromUnsigned(const RegisterInfo *reg_info, uint64_t uval);
bool ConvertBetweenRegisterKinds(lldb::RegisterKind source_rk,
uint32_t source_regnum,
lldb::RegisterKind target_rk,
uint32_t &target_regnum);
// lldb::ExecutionContextScope pure virtual functions
lldb::TargetSP CalculateTarget() override;
lldb::ProcessSP CalculateProcess() override;
lldb::ThreadSP CalculateThread() override;
lldb::StackFrameSP CalculateStackFrame() override;
void CalculateExecutionContext(ExecutionContext &exe_ctx) override;
uint32_t GetStopID() const { return m_stop_id; }
void SetStopID(uint32_t stop_id) { m_stop_id = stop_id; }
/// Indicates that this frame is currently executing code,
/// that the PC value is not a return-pc but an actual executing
/// instruction. Some places in lldb will treat a return-pc
/// value differently than the currently-executing-pc value,
/// and this method can indicate if that should be done.
/// The base class implementation only uses the frame index,
/// but subclasses may have additional information that they
/// can use to detect frames in this state, for instance a
/// frame above a trap handler (sigtramp etc)..
virtual bool BehavesLikeZerothFrame() const {
return m_concrete_frame_idx == 0;
// Classes that inherit from RegisterContext can see and modify these
Thread &m_thread; // The thread that this register context belongs to.
uint32_t m_concrete_frame_idx; // The concrete frame index for this register
// context
uint32_t m_stop_id; // The stop ID that any data in this context is valid for
// For RegisterContext only
RegisterContext(const RegisterContext &) = delete;
const RegisterContext &operator=(const RegisterContext &) = delete;
} // namespace lldb_private