SourceManager.h

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//===-- SourceManager.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_CORE_SOURCEMANAGER_H
#define LLDB_CORE_SOURCEMANAGER_H
 
#include "lldb/Utility/Checksum.h"
#include "lldb/Utility/FileSpec.h"
#include "lldb/Utility/Locked.h"
#include "lldb/Utility/SupportFile.h"
#include "lldb/lldb-defines.h"
#include "lldb/lldb-forward.h"
 
#include "llvm/Support/Chrono.h"
#include "llvm/Support/RWMutex.h"
 
#include <cstddef>
#include <cstdint>
#include <map>
#include <memory>
#include <optional>
#include <shared_mutex>
#include <string>
#include <vector>
 
namespace lldb_private {
class RegularExpression;
class Stream;
class SymbolContextList;
class Target;
 
class SourceManager {
public:
  class File {
    friend bool operator==(const SourceManager::File &lhs,
                           const SourceManager::File &rhs);
 
  public:
    File(SupportFileNSP support_file_nsp, lldb::TargetSP target_sp);
    File(SupportFileNSP support_file_nsp, lldb::DebuggerSP debugger_sp);
 
    bool ModificationTimeIsStale() const;
    bool PathRemappingIsStale() const;
 
    size_t DisplaySourceLines(
        uint32_t line, std::optional<size_t> column, uint32_t context_before,
        uint32_t context_after, Stream *s,
        lldb::LanguageType language_type = lldb::eLanguageTypeUnknown);
    void FindLinesMatchingRegex(RegularExpression &regex, uint32_t start_line,
                                uint32_t end_line,
                                std::vector<uint32_t> &match_lines);
 
    bool GetLine(uint32_t line_no, std::string &buffer);
 
    uint32_t GetLineOffset(uint32_t line);
 
    bool LineIsValid(uint32_t line);
 
    SupportFileNSP GetSupportFile() const {
      assert(m_support_file_nsp && "SupportFileNSP must always be valid");
      return m_support_file_nsp;
    }
 
    uint32_t GetSourceMapModificationID() const { return m_source_map_mod_id; }
 
    const char *PeekLineData(uint32_t line);
 
    uint32_t GetLineLength(uint32_t line, bool include_newline_chars);
 
    uint32_t GetNumLines();
 
    llvm::sys::TimePoint<> GetTimestamp() const { return m_mod_time; }
 
    const Checksum &GetChecksum() const { return m_checksum; }
 
    std::once_flag &GetChecksumWarningOnceFlag() {
      return m_checksum_warning_once_flag;
    }
 
  protected:
    /// Set file and update modification time.
    void SetSupportFile(SupportFileNSP support_file_nsp);
 
    bool CalculateLineOffsets(uint32_t line = UINT32_MAX);
 
    /// The support file. If the target has source mappings, this might be
    /// different from the original support file passed to the constructor.
    SupportFileNSP m_support_file_nsp;
 
    /// Keep track of the on-disk checksum.
    Checksum m_checksum;
 
    /// Once flag for emitting a checksum mismatch warning.
    std::once_flag m_checksum_warning_once_flag;
 
    // Keep the modification time that this file data is valid for
    llvm::sys::TimePoint<> m_mod_time;
 
    // If the target uses path remappings, be sure to clear our notion of a
    // source file if the path modification ID changes
    uint32_t m_source_map_mod_id = 0;
    lldb::DataBufferSP m_data_sp;
    typedef std::vector<uint32_t> LineOffsets;
 
    /// The line offsets for this file.
    /// This member that is computed after this File was created, so write
    /// access can happen from several threads..
    Guarded<LineOffsets, std::shared_mutex> m_offsets;
 
    lldb::DebuggerWP m_debugger_wp;
    lldb::TargetWP m_target_wp;
 
  private:
    void CommonInitializer(SupportFileNSP support_file_nsp,
                           lldb::TargetSP target_sp);
    void CommonInitializerImpl(SupportFileNSP support_file_nsp,
                               lldb::TargetSP target_sp);
  };
 
  typedef std::shared_ptr<File> FileSP;
 
  /// The SourceFileCache class separates the source manager from the cache of
  /// source files. There is one source manager per Target but both the Debugger
  /// and the Process have their own source caches.
  ///
  /// The SourceFileCache just handles adding, storing, removing and looking up
  /// source files. The caching policies are implemented in
  /// SourceManager::GetFile.
  class SourceFileCache {
  public:
    SourceFileCache() = default;
    ~SourceFileCache() = default;
 
    void AddSourceFile(const FileSpec &file_spec, FileSP file_sp);
    void RemoveSourceFile(const FileSP &file_sp);
 
    FileSP FindSourceFile(const FileSpec &file_spec) const;
 
    // Removes all elements from the cache.
    void Clear() { m_file_cache.clear(); }
 
    void Dump(Stream &stream) const;
 
  private:
    void AddSourceFileImpl(const FileSpec &file_spec, FileSP file_sp);
 
    typedef std::map<FileSpec, FileSP> FileCache;
    FileCache m_file_cache;
 
    mutable llvm::sys::RWMutex m_mutex;
  };
 
  /// A source manager can be made with a valid Target, in which case it can use
  /// the path remappings to find source files that are not in their build
  /// locations.  Without a target it won't be able to do this.
  /// @{
  SourceManager(const lldb::DebuggerSP &debugger_sp);
  SourceManager(const lldb::TargetSP &target_sp);
  /// @}
 
  ~SourceManager();
 
  FileSP GetLastFile() { return GetFile(m_last_support_file_nsp); }
  bool AtLastLine(bool reverse) {
    return m_last_line == UINT32_MAX || (reverse && m_last_line == 1);
  }
 
  size_t DisplaySourceLinesWithLineNumbers(
      SupportFileNSP support_file_nsp, uint32_t line, uint32_t column,
      uint32_t context_before, uint32_t context_after,
      const char *current_line_cstr, Stream *s,
      const SymbolContextList *bp_locs = nullptr,
      lldb::LanguageType language_type = lldb::eLanguageTypeUnknown);
 
  // This variant uses the last file we visited.
  size_t DisplaySourceLinesWithLineNumbersUsingLastFile(
      uint32_t start_line, uint32_t count, uint32_t curr_line, uint32_t column,
      const char *current_line_cstr, Stream *s,
      const SymbolContextList *bp_locs = nullptr,
      lldb::LanguageType language_type = lldb::eLanguageTypeUnknown);
 
  size_t DisplayMoreWithLineNumbers(
      Stream *s, uint32_t count, bool reverse,
      const SymbolContextList *bp_locs = nullptr,
      lldb::LanguageType language_type = lldb::eLanguageTypeUnknown);
 
  bool SetDefaultFileAndLine(SupportFileNSP support_file_nsp, uint32_t line);
 
  struct SupportFileAndLine {
    SupportFileNSP support_file_nsp;
    uint32_t line;
    SupportFileAndLine(SupportFileNSP support_file_nsp, uint32_t line)
        : support_file_nsp(support_file_nsp), line(line) {}
  };
 
  std::optional<SupportFileAndLine> GetDefaultFileAndLine();
 
  bool DefaultFileAndLineSet() {
    return (GetFile(m_last_support_file_nsp).get() != nullptr);
  }
 
  void FindLinesMatchingRegex(SupportFileNSP support_file_nsp,
                              RegularExpression &regex, uint32_t start_line,
                              uint32_t end_line,
                              std::vector<uint32_t> &match_lines);
 
  FileSP GetFile(SupportFileNSP support_file_nsp);
 
protected:
  SupportFileNSP m_last_support_file_nsp;
  uint32_t m_last_line;
  uint32_t m_last_count;
  bool m_default_set;
  lldb::TargetWP m_target_wp;
  lldb::DebuggerWP m_debugger_wp;
 
private:
  SourceManager(const SourceManager &) = delete;
  const SourceManager &operator=(const SourceManager &) = delete;
};
 
bool operator==(const SourceManager::File &lhs, const SourceManager::File &rhs);
 
} // namespace lldb_private
 
#endif // LLDB_CORE_SOURCEMANAGER_H