BreakpointResolver.h

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//===-- BreakpointResolver.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_BREAKPOINT_BREAKPOINTRESOLVER_H
#define LLDB_BREAKPOINT_BREAKPOINTRESOLVER_H

#include "lldb/Breakpoint/Breakpoint.h"
#include "lldb/Core/Address.h"
#include "lldb/Core/SearchFilter.h"
#include "lldb/Utility/ConstString.h"
#include "lldb/Utility/FileSpec.h"
#include "lldb/Utility/RegularExpression.h"
#include "lldb/lldb-private.h"

namespace lldb_private {

/// \class BreakpointResolver BreakpointResolver.h
/// "lldb/Breakpoint/BreakpointResolver.h" This class works with SearchFilter
/// to resolve logical breakpoints to their of concrete breakpoint locations.

/// General Outline:
/// The BreakpointResolver is a Searcher.  In that protocol, the SearchFilter
/// asks the question "At what depth of the symbol context descent do you want
/// your callback to get called?" of the filter.  The resolver answers this
/// question (in the GetDepth method) and provides the resolution callback.
/// Each Breakpoint has a BreakpointResolver, and it calls either
/// ResolveBreakpoint or ResolveBreakpointInModules to tell it to look for new
/// breakpoint locations.

class BreakpointResolver : public Searcher {
  friend class Breakpoint;

public:
  /// The breakpoint resolver need to have a breakpoint for "ResolveBreakpoint
  /// to make sense.  It can be constructed without a breakpoint, but you have
  /// to call SetBreakpoint before ResolveBreakpoint.
  ///
  /// \param[in] bkpt
  ///   The breakpoint that owns this resolver.
  /// \param[in] resolverType
  ///   The concrete breakpoint resolver type for this breakpoint.
  BreakpointResolver(const lldb::BreakpointSP &bkpt,
                     unsigned char resolverType,
                     lldb::addr_t offset = 0);

  /// The Destructor is virtual, all significant breakpoint resolvers derive
  /// from this class.
  ~BreakpointResolver() override;

  /// This sets the breakpoint for this resolver.
  ///
  /// \param[in] bkpt
  ///   The breakpoint that owns this resolver.
  void SetBreakpoint(const lldb::BreakpointSP &bkpt);

  /// This gets the breakpoint for this resolver.
  lldb::BreakpointSP GetBreakpoint() const {
    auto breakpoint_sp = m_breakpoint.expired() ? lldb::BreakpointSP() :
                                                  m_breakpoint.lock();
    assert(breakpoint_sp);
    return breakpoint_sp;
  }

  /// This updates the offset for this breakpoint.  All the locations
  /// currently set for this breakpoint will have their offset adjusted when
  /// this is called.
  ///
  /// \param[in] offset
  ///   The offset to add to all locations.
  void SetOffset(lldb::addr_t offset);

  lldb::addr_t GetOffset() const { return m_offset; }

  /// In response to this method the resolver scans all the modules in the
  /// breakpoint's target, and adds any new locations it finds.
  ///
  /// \param[in] filter
  ///   The filter that will manage the search for this resolver.
  virtual void ResolveBreakpoint(SearchFilter &filter);

  /// In response to this method the resolver scans the modules in the module
  /// list \a modules, and adds any new locations it finds.
  ///
  /// \param[in] filter
  ///   The filter that will manage the search for this resolver.
  virtual void ResolveBreakpointInModules(SearchFilter &filter,
                                          ModuleList &modules);

  /// Prints a canonical description for the breakpoint to the stream \a s.
  ///
  /// \param[in] s
  ///   Stream to which the output is copied.
  void GetDescription(Stream *s) override = 0;

  /// Standard "Dump" method.  At present it does nothing.
  virtual void Dump(Stream *s) const = 0;

  /// This section handles serializing and deserializing from StructuredData
  /// objects.

  static lldb::BreakpointResolverSP
  CreateFromStructuredData(const StructuredData::Dictionary &resolver_dict,
                           Status &error);

  virtual StructuredData::ObjectSP SerializeToStructuredData() {
    return StructuredData::ObjectSP();
  }

  static const char *GetSerializationKey() { return "BKPTResolver"; }

  static const char *GetSerializationSubclassKey() { return "Type"; }

  static const char *GetSerializationSubclassOptionsKey() { return "Options"; }

  StructuredData::DictionarySP
  WrapOptionsDict(StructuredData::DictionarySP options_dict_sp);

  /// An enumeration for keeping track of the concrete subclass that is
  /// actually instantiated. Values of this enumeration are kept in the
  /// BreakpointResolver's SubclassID field. They are used for concrete type
  /// identification.
  enum ResolverTy {
    FileLineResolver = 0, // This is an instance of BreakpointResolverFileLine
    AddressResolver,      // This is an instance of BreakpointResolverAddress
    NameResolver,         // This is an instance of BreakpointResolverName
    FileRegexResolver,
    PythonResolver,
    ExceptionResolver,
    LastKnownResolverType = ExceptionResolver,
    UnknownResolver
  };

  // Translate the Ty to name for serialization, the "+2" is one for size vrs.
  // index, and one for UnknownResolver.
  static const char *g_ty_to_name[LastKnownResolverType + 2];

  /// getResolverID - Return an ID for the concrete type of this object.  This
  /// is used to implement the LLVM classof checks.  This should not be used
  /// for any other purpose, as the values may change as LLDB evolves.
  unsigned getResolverID() const { return SubclassID; }

  enum ResolverTy GetResolverTy() {
    if (SubclassID > ResolverTy::LastKnownResolverType)
      return ResolverTy::UnknownResolver;
    else
      return (enum ResolverTy)SubclassID;
  }

  const char *GetResolverName() { return ResolverTyToName(GetResolverTy()); }

  static const char *ResolverTyToName(enum ResolverTy);

  static ResolverTy NameToResolverTy(llvm::StringRef name);

  virtual lldb::BreakpointResolverSP
  CopyForBreakpoint(lldb::BreakpointSP &breakpoint) = 0;

protected:
  // Used for serializing resolver options:
  // The options in this enum and the strings in the g_option_names must be
  // kept in sync.
  enum class OptionNames : uint32_t {
    AddressOffset = 0,
    ExactMatch,
    FileName,
    Inlines,
    LanguageName,
    LineNumber,
    Column,
    ModuleName,
    NameMaskArray,
    Offset,
    PythonClassName,
    RegexString,
    ScriptArgs,
    SectionName,
    SearchDepth,
    SkipPrologue,
    SymbolNameArray,
    LastOptionName
  };
  static const char
      *g_option_names[static_cast<uint32_t>(OptionNames::LastOptionName)];

  virtual void NotifyBreakpointSet() {};

public:
  static const char *GetKey(OptionNames enum_value) {
    return g_option_names[static_cast<uint32_t>(enum_value)];
  }

protected:
  /// Takes a symbol context list of matches which supposedly represent the
  /// same file and line number in a CU, and find the nearest actual line
  /// number that matches, and then filter down the matching addresses to
  /// unique entries, and skip the prologue if asked to do so, and then set
  /// breakpoint locations in this breakpoint for all the resultant addresses.
  /// When \p column is nonzero the \p line and \p column args are used to
  /// filter the results to find the first breakpoint >= (line, column).
  void SetSCMatchesByLine(SearchFilter &filter, SymbolContextList &sc_list,
                          bool skip_prologue, llvm::StringRef log_ident,
                          uint32_t line = 0, uint32_t column = 0);
  void SetSCMatchesByLine(SearchFilter &, SymbolContextList &, bool,
                          const char *) = delete;

  lldb::BreakpointLocationSP AddLocation(Address loc_addr,
                                         bool *new_location = nullptr);

private:
  /// Helper for \p SetSCMatchesByLine.
  void AddLocation(SearchFilter &filter, const SymbolContext &sc,
                   bool skip_prologue, llvm::StringRef log_ident);

  lldb::BreakpointWP m_breakpoint; // This is the breakpoint we add locations to.
  lldb::addr_t m_offset;    // A random offset the user asked us to add to any
                            // breakpoints we set.

  // Subclass identifier (for llvm isa/dyn_cast)
  const unsigned char SubclassID;
  BreakpointResolver(const BreakpointResolver &) = delete;
  const BreakpointResolver &operator=(const BreakpointResolver &) = delete;
};

} // namespace lldb_private

#endif // LLDB_BREAKPOINT_BREAKPOINTRESOLVER_H