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//===-- BreakpointSite.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 <list>
#include <mutex>
#include "lldb/Breakpoint/BreakpointLocationCollection.h"
#include "lldb/Breakpoint/StoppointSite.h"
#include "lldb/Utility/LLDBAssert.h"
#include "lldb/Utility/UserID.h"
#include "lldb/lldb-forward.h"
namespace lldb_private {
/// \class BreakpointSite BreakpointSite.h "lldb/Breakpoint/BreakpointSite.h"
/// Class that manages the actual breakpoint that will be inserted into the
/// running program.
/// The BreakpointSite class handles the physical breakpoint that is actually
/// inserted in the target program. As such, it is also the one that gets
/// hit, when the program stops. It keeps a list of all BreakpointLocations
/// that share this physical site. When the breakpoint is hit, all the
/// locations are informed by the breakpoint site. Breakpoint sites are owned
/// by the process.
class BreakpointSite : public std::enable_shared_from_this<BreakpointSite>,
public StoppointSite {
enum Type {
eSoftware, // Breakpoint opcode has been written to memory and
// m_saved_opcode
// and m_trap_opcode contain the saved and written opcode.
eHardware, // Breakpoint site is set as a hardware breakpoint
eExternal // Breakpoint site is managed by an external debug nub or
// debug interface where memory reads transparently will not
// display any breakpoint opcodes.
~BreakpointSite() override;
// This section manages the breakpoint traps
/// Returns the Opcode Bytes for this breakpoint
uint8_t *GetTrapOpcodeBytes();
/// Returns the Opcode Bytes for this breakpoint - const version
const uint8_t *GetTrapOpcodeBytes() const;
/// Get the size of the trap opcode for this address
size_t GetTrapOpcodeMaxByteSize() const;
/// Sets the trap opcode
bool SetTrapOpcode(const uint8_t *trap_opcode, uint32_t trap_opcode_size);
/// Gets the original instruction bytes that were overwritten by the trap
uint8_t *GetSavedOpcodeBytes();
/// Gets the original instruction bytes that were overwritten by the trap
/// const version
const uint8_t *GetSavedOpcodeBytes() const;
/// Says whether \a addr and size \a size intersects with the address \a
/// intersect_addr
bool IntersectsRange(lldb::addr_t addr, size_t size,
lldb::addr_t *intersect_addr, size_t *intersect_size,
size_t *opcode_offset) const;
/// Tells whether the current breakpoint site is enabled or not
/// This is a low-level enable bit for the breakpoint sites. If a
/// breakpoint site has no enabled owners, it should just get removed. This
/// enable/disable is for the low-level target code to enable and disable
/// breakpoint sites when single stepping, etc.
bool IsEnabled() const;
/// Sets whether the current breakpoint site is enabled or not
/// \param[in] enabled
/// \b true if the breakpoint is enabled, \b false otherwise.
void SetEnabled(bool enabled);
/// Enquires of the breakpoint locations that produced this breakpoint site
/// whether we should stop at this location.
/// \param[in] context
/// This contains the information about this stop.
/// \return
/// \b true if we should stop, \b false otherwise.
bool ShouldStop(StoppointCallbackContext *context) override;
/// Standard Dump method
void Dump(Stream *s) const override;
/// The "Owners" are the breakpoint locations that share this breakpoint
/// site. The method adds the \a owner to this breakpoint site's owner list.
/// \param[in] owner
/// \a owner is the Breakpoint Location to add.
void AddOwner(const lldb::BreakpointLocationSP &owner);
/// This method returns the number of breakpoint locations currently located
/// at this breakpoint site.
/// \return
/// The number of owners.
size_t GetNumberOfOwners();
/// This method returns the breakpoint location at index \a index located at
/// this breakpoint site. The owners are listed ordinally from 0 to
/// GetNumberOfOwners() - 1 so you can use this method to iterate over the
/// owners
/// \param[in] idx
/// The index in the list of owners for which you wish the owner location.
/// \return
/// A shared pointer to the breakpoint location at that index.
lldb::BreakpointLocationSP GetOwnerAtIndex(size_t idx);
/// This method copies the breakpoint site's owners into a new collection.
/// It does this while the owners mutex is locked.
/// \param[out] out_collection
/// The BreakpointLocationCollection into which to put the owners
/// of this breakpoint site.
/// \return
/// The number of elements copied into out_collection.
size_t CopyOwnersList(BreakpointLocationCollection &out_collection);
/// Check whether the owners of this breakpoint site have any thread
/// specifiers, and if yes, is \a thread contained in any of these
/// specifiers.
/// \param[in] thread
/// The thread against which to test.
/// return
/// \b true if the collection contains at least one location that
/// would be valid for this thread, false otherwise.
bool ValidForThisThread(Thread &thread);
/// Print a description of this breakpoint site to the stream \a s.
/// GetDescription tells you about the breakpoint site's owners. Use
/// BreakpointSite::Dump(Stream *) to get information about the breakpoint
/// site itself.
/// \param[in] s
/// The stream to which to print the description.
/// \param[in] level
/// The description level that indicates the detail level to
/// provide.
/// \see lldb::DescriptionLevel
void GetDescription(Stream *s, lldb::DescriptionLevel level);
/// Tell whether a breakpoint has a location at this site.
/// \param[in] bp_id
/// The breakpoint id to query.
/// \result
/// \b true if bp_id has a location that is at this site,
/// \b false otherwise.
bool IsBreakpointAtThisSite(lldb::break_id_t bp_id);
/// Tell whether ALL the breakpoints in the location collection are
/// internal.
/// \result
/// \b true if all breakpoint locations are owned by internal breakpoints,
/// \b false otherwise.
bool IsInternal() const;
bool IsHardware() const override {
lldbassert(BreakpointSite::Type::eHardware == GetType() ||
return BreakpointSite::Type::eHardware == GetType();
BreakpointSite::Type GetType() const { return m_type; }
void SetType(BreakpointSite::Type type) { m_type = type; }
friend class Process;
friend class BreakpointLocation;
// The StopInfoBreakpoint knows when it is processing a hit for a thread for
// a site, so let it be the one to manage setting the location hit count once
// and only once.
friend class StopInfoBreakpoint;
void BumpHitCounts();
/// The method removes the owner at \a break_loc_id from this breakpoint
/// list.
size_t RemoveOwner(lldb::break_id_t break_id, lldb::break_id_t break_loc_id);
BreakpointSite::Type m_type; ///< The type of this breakpoint site.
uint8_t m_saved_opcode[8]; ///< The saved opcode bytes if this breakpoint site
///uses trap opcodes.
uint8_t m_trap_opcode[8]; ///< The opcode that was used to create the
///breakpoint if it is a software breakpoint site.
m_enabled; ///< Boolean indicating if this breakpoint site enabled or not.
// Consider adding an optimization where if there is only one owner, we don't
// store a list. The usual case will be only one owner...
BreakpointLocationCollection m_owners; ///< This has the BreakpointLocations
///that share this breakpoint site.
m_owners_mutex; ///< This mutex protects the owners collection.
static lldb::break_id_t GetNextID();
// Only the Process can create breakpoint sites in
// Process::CreateBreakpointSite (lldb::BreakpointLocationSP &, bool).
BreakpointSite(BreakpointSiteList *list,
const lldb::BreakpointLocationSP &owner, lldb::addr_t m_addr,
bool use_hardware);
BreakpointSite(const BreakpointSite &) = delete;
const BreakpointSite &operator=(const BreakpointSite &) = delete;
} // namespace lldb_private