//===-- SourceManager.cpp -------------------------------------------------===//

//

// 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

//

//===----------------------------------------------------------------------===//

#include "lldb/Core/SourceManager.h"

#include "lldb/Core/Address.h"

#include "lldb/Core/AddressRange.h"

#include "lldb/Core/Debugger.h"

#include "lldb/Core/FormatEntity.h"

#include "lldb/Core/Highlighter.h"

#include "lldb/Core/Module.h"

#include "lldb/Core/ModuleList.h"

#include "lldb/Host/FileSystem.h"

#include "lldb/Symbol/CompileUnit.h"

#include "lldb/Symbol/Function.h"

#include "lldb/Symbol/LineEntry.h"

#include "lldb/Symbol/SymbolContext.h"

#include "lldb/Target/PathMappingList.h"

#include "lldb/Target/Process.h"

#include "lldb/Target/Target.h"

#include "lldb/Utility/AnsiTerminal.h"

#include "lldb/Utility/ConstString.h"

#include "lldb/Utility/DataBuffer.h"

#include "lldb/Utility/LLDBLog.h"

#include "lldb/Utility/Log.h"

#include "lldb/Utility/RegularExpression.h"

#include "lldb/Utility/Stream.h"

#include "lldb/lldb-enumerations.h"

#include "llvm/ADT/Twine.h"

#include <memory>

#include <optional>

#include <utility>

#include <cassert>

#include <cstdio>

namespace lldb_private {

class ExecutionContext;

}

namespace lldb_private {

class ValueObject;

}

using namespace lldb;

using namespace lldb_private;

static inline bool is_newline_char(char ch) { return ch == '\n' || 
ch == '\r'3.30M
; }

static void resolve_tilde(FileSpec &file_spec) {

  if (!FileSystem::Instance().Exists(file_spec) &&

      
file_spec.GetDirectory()20
 &&

      
file_spec.GetDirectory().GetCString()[0] == '~'18
) {

    FileSystem::Instance().Resolve(file_spec);

  }

}

// SourceManager constructor

SourceManager::SourceManager(const TargetSP &target_sp)

    : m_last_line(0), m_last_count(0), m_default_set(false),

      m_target_wp(target_sp),

      m_debugger_wp(target_sp->GetDebugger().shared_from_this()) {}

SourceManager::SourceManager(const DebuggerSP &debugger_sp)

    : m_last_line(0), m_last_count(0), m_default_set(false), m_target_wp(),

      m_debugger_wp(debugger_sp) {}

// Destructor

SourceManager::~SourceManager() = default;

SourceManager::FileSP SourceManager::GetFile(const FileSpec &file_spec) {

  if (!file_spec)

    return {};

  Log *log = GetLog(LLDBLog::Source);

  DebuggerSP debugger_sp(m_debugger_wp.lock());

  TargetSP target_sp(m_target_wp.lock());

  if (!debugger_sp || !debugger_sp->GetUseSourceCache()) {

    LLDB_LOG(log, "Source file caching disabled: creating new source file: {0}",

             file_spec);

    if (target_sp)

      return std::make_shared<File>(file_spec, target_sp);

    return std::make_shared<File>(file_spec, debugger_sp);

  }

  ProcessSP process_sp = target_sp ? 
target_sp->GetProcessSP()13.7k
 : 
ProcessSP()76
;

  // Check the process source cache first. This is the fast path which avoids

  // touching the file system unless the path remapping has changed.

  if (process_sp) {

    if (FileSP file_sp =

            process_sp->GetSourceFileCache().FindSourceFile(file_spec)) {

      LLDB_LOG(log, "Found source file in the process cache: {0}", file_spec);

      if (file_sp->PathRemappingIsStale()) {

        LLDB_LOG(log, "Path remapping is stale: removing file from caches: {0}",

                 file_spec);

        // Remove the file from the debugger and process cache. Otherwise we'll

        // hit the same issue again below when querying the debugger cache.

        debugger_sp->GetSourceFileCache().RemoveSourceFile(file_sp);

        process_sp->GetSourceFileCache().RemoveSourceFile(file_sp);

        file_sp.reset();

      } else {

        return file_sp;

      }

    }

  }

  // Cache miss in the process cache. Check the debugger source cache.

  FileSP file_sp = debugger_sp->GetSourceFileCache().FindSourceFile(file_spec);

  // We found the file in the debugger cache. Check if anything invalidated our

  // cache result.

  if (file_sp)

    LLDB_LOG(log, "Found source file in the debugger cache: {0}", file_spec);

  // Check if the path remapping has changed.

  if (file_sp && 
file_sp->PathRemappingIsStale()5.26k
) {

    LLDB_LOG(log, "Path remapping is stale: {0}", file_spec);

    file_sp.reset();

  }

  // Check if the modification time has changed.

  if (file_sp && 
file_sp->ModificationTimeIsStale()5.25k
) {

    LLDB_LOG(log, "Modification time is stale: {0}", file_spec);

    file_sp.reset();

  }

  // Check if the file exists on disk.

  if (file_sp && 
!FileSystem::Instance().Exists(file_sp->GetFileSpec())5.25k
) {

    LLDB_LOG(log, "File doesn't exist on disk: {0}", file_spec);

    file_sp.reset();

  }

  // If at this point we don't have a valid file, it means we either didn't find

  // it in the debugger cache or something caused it to be invalidated.

  if (!file_sp) {

    LLDB_LOG(log, "Creating and caching new source file: {0}", file_spec);

    // (Re)create the file.

    if (target_sp)

      file_sp = std::make_shared<File>(file_spec, target_sp);

    else

      file_sp = std::make_shared<File>(file_spec, debugger_sp);

    // Add the file to the debugger and process cache. If the file was

    // invalidated, this will overwrite it.

    debugger_sp->GetSourceFileCache().AddSourceFile(file_spec, file_sp);

    if (process_sp)

      process_sp->GetSourceFileCache().AddSourceFile(file_spec, file_sp);

  }

  return file_sp;

}

static bool should_highlight_source(DebuggerSP debugger_sp) {

  if (!debugger_sp)

    return false;

  // We don't use ANSI stop column formatting if the debugger doesn't think it

  // should be using color.

  if (!debugger_sp->GetUseColor())

    return false;

  return debugger_sp->GetHighlightSource();

}

static bool should_show_stop_column_with_ansi(DebuggerSP debugger_sp) {

  // We don't use ANSI stop column formatting if we can't lookup values from

  // the debugger.

  if (!debugger_sp)

    return false;

  // We don't use ANSI stop column formatting if the debugger doesn't think it

  // should be using color.

  if (!debugger_sp->GetUseColor())

    return false;

  // We only use ANSI stop column formatting if we're either supposed to show

  // ANSI where available (which we know we have when we get to this point), or

  // if we're only supposed to use ANSI.

  const auto value = debugger_sp->GetStopShowColumn();

  return ((value == eStopShowColumnAnsiOrCaret) ||

          
(value == eStopShowColumnAnsi)0
);

}

static bool should_show_stop_column_with_caret(DebuggerSP debugger_sp) {

  // We don't use text-based stop column formatting if we can't lookup values

  // from the debugger.

  if (!debugger_sp)

    return false;

  // If we're asked to show the first available of ANSI or caret, then we do

  // show the caret when ANSI is not available.

  const auto value = debugger_sp->GetStopShowColumn();

  if ((value == eStopShowColumnAnsiOrCaret) && !debugger_sp->GetUseColor())

    return true;

  // The only other time we use caret is if we're explicitly asked to show

  // caret.

  return value == eStopShowColumnCaret;

}

static bool should_show_stop_line_with_ansi(DebuggerSP debugger_sp) {

  return debugger_sp && debugger_sp->GetUseColor();

}

size_t SourceManager::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) {

  if (count == 0)

    return 0;

  Stream::ByteDelta delta(*s);

  if (start_line == 0) {

    if (m_last_line != 0 && m_last_line != UINT32_MAX)

      start_line = m_last_line + m_last_count;

    else

      start_line = 1;

  }

  if (!m_default_set) {

    FileSpec tmp_spec;

    uint32_t tmp_line;

    GetDefaultFileAndLine(tmp_spec, tmp_line);

  }

  m_last_line = start_line;

  m_last_count = count;

  if (FileSP last_file_sp = GetLastFile()) {

    const uint32_t end_line = start_line + count - 1;

    for (uint32_t line = start_line; line <= end_line; 
++line9.97k
) {

      if (!last_file_sp->LineIsValid(line)) {

        m_last_line = UINT32_MAX;

        break;

      }

      std::string prefix;

      if (bp_locs) {

        uint32_t bp_count = bp_locs->NumLineEntriesWithLine(line);

        if (bp_count > 0)

          prefix = llvm::formatv("[{0}]", bp_count);

        else

          prefix = "    ";

      }

      char buffer[3];

      snprintf(buffer, sizeof(buffer), "%2.2s",

               (line == curr_line) ? 
current_line_cstr1.52k
 : 
""8.44k
);

      std::string current_line_highlight(buffer);

      auto debugger_sp = m_debugger_wp.lock();

      if (should_show_stop_line_with_ansi(debugger_sp)) {

        current_line_highlight = ansi::FormatAnsiTerminalCodes(

            (debugger_sp->GetStopShowLineMarkerAnsiPrefix() +

             current_line_highlight +

             debugger_sp->GetStopShowLineMarkerAnsiSuffix())

                .str());

      }

      s->Printf("%s%s %-4u\t", prefix.c_str(), current_line_highlight.c_str(),

                line);

      // So far we treated column 0 as a special 'no column value', but

      // DisplaySourceLines starts counting columns from 0 (and no column is

      // expressed by passing an empty optional).

      std::optional<size_t> columnToHighlight;

      if (line == curr_line && 
column1.52k
)

        columnToHighlight = column - 1;

      size_t this_line_size =

          last_file_sp->DisplaySourceLines(line, columnToHighlight, 0, 0, s);

      if (column != 0 && 
line == curr_line9.77k
 &&

          
should_show_stop_column_with_caret(debugger_sp)1.48k
) {

        // Display caret cursor.

        std::string src_line;

        last_file_sp->GetLine(line, src_line);

        s->Printf("    \t");

        // Insert a space for every non-tab character in the source line.

        for (size_t i = 0; i + 1 < column && 
i < src_line.length()19.6k
; 
++i19.6k
)

          s->PutChar(src_line[i] == '\t' ? 
'\t'58
 : 
' '19.6k
);

        // Now add the caret.

        s->Printf("^\n");

      }

      if (this_line_size == 0) {

        m_last_line = UINT32_MAX;

        break;

      }

    }

  }

  return *delta;

}

size_t SourceManager::DisplaySourceLinesWithLineNumbers(

    const FileSpec &file_spec, 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) {

  FileSP file_sp(GetFile(file_spec));

  uint32_t start_line;

  uint32_t count = context_before + context_after + 1;

  if (line > context_before)

    start_line = line - context_before;

  else

    start_line = 1;

  FileSP last_file_sp(GetLastFile());

  if (last_file_sp.get() != file_sp.get()) {

    if (line == 0)

      m_last_line = 0;

    m_last_file_spec = file_spec;

  }

  return DisplaySourceLinesWithLineNumbersUsingLastFile(

      start_line, count, line, column, current_line_cstr, s, bp_locs);

}

size_t SourceManager::DisplayMoreWithLineNumbers(

    Stream *s, uint32_t count, bool reverse, const SymbolContextList *bp_locs) {

  // If we get called before anybody has set a default file and line, then try

  // to figure it out here.

  FileSP last_file_sp(GetLastFile());

  const bool have_default_file_line = last_file_sp && 
m_last_line > 00
;

  if (!m_default_set) {

    FileSpec tmp_spec;

    uint32_t tmp_line;

    GetDefaultFileAndLine(tmp_spec, tmp_line);

  }

  if (last_file_sp) {

    if (m_last_line == UINT32_MAX)

      return 0;

    if (reverse && m_last_line == 1)

      return 0;

    if (count > 0)

      m_last_count = count;

    else if (m_last_count == 0)

      m_last_count = 10;

    if (m_last_line > 0) {

      if (reverse) {

        // If this is the first time we've done a reverse, then back up one

        // more time so we end up showing the chunk before the last one we've

        // shown:

        if (m_last_line > m_last_count)

          m_last_line -= m_last_count;

        else

          m_last_line = 1;

      } else if (have_default_file_line)

        m_last_line += m_last_count;

    } else

      m_last_line = 1;

    const uint32_t column = 0;

    return DisplaySourceLinesWithLineNumbersUsingLastFile(

        m_last_line, m_last_count, UINT32_MAX, column, "", s, bp_locs);

  }

  return 0;

}

bool SourceManager::SetDefaultFileAndLine(const FileSpec &file_spec,

                                          uint32_t line) {

  m_default_set = true;

  FileSP file_sp(GetFile(file_spec));

  if (file_sp) {

    m_last_line = line;

    m_last_file_spec = file_spec;

    return true;

  } else {

    return false;

  }

}

bool SourceManager::GetDefaultFileAndLine(FileSpec &file_spec, uint32_t &line) {

  if (FileSP last_file_sp = GetLastFile()) {

    file_spec = m_last_file_spec;

    line = m_last_line;

    return true;

  } else 
if (61
!m_default_set61
) {

    TargetSP target_sp(m_target_wp.lock());

    if (target_sp) {

      // If nobody has set the default file and line then try here.  If there's

      // no executable, then we will try again later when there is one.

      // Otherwise, if we can't find it we won't look again, somebody will have

      // to set it (for instance when we stop somewhere...)

      Module *executable_ptr = target_sp->GetExecutableModulePointer();

      if (executable_ptr) {

        SymbolContextList sc_list;

        ConstString main_name("main");

        ModuleFunctionSearchOptions function_options;

        function_options.include_symbols =

            false; // Force it to be a debug symbol.

        function_options.include_inlines = true;

        executable_ptr->FindFunctions(main_name, CompilerDeclContext(),

                                      lldb::eFunctionNameTypeBase,

                                      function_options, sc_list);

        for (const SymbolContext &sc : sc_list) {

          if (sc.function) {

            lldb_private::LineEntry line_entry;

            if (sc.function->GetAddressRange()

                    .GetBaseAddress()

                    .CalculateSymbolContextLineEntry(line_entry)) {

              SetDefaultFileAndLine(line_entry.file, line_entry.line);

              file_spec = m_last_file_spec;

              line = m_last_line;

              return true;

            }

          }

        }

      }

    }

  }

  return false;

}

void SourceManager::FindLinesMatchingRegex(FileSpec &file_spec,

                                           RegularExpression &regex,

                                           uint32_t start_line,

                                           uint32_t end_line,

                                           std::vector<uint32_t> &match_lines) {

  match_lines.clear();

  FileSP file_sp = GetFile(file_spec);

  if (!file_sp)

    return;

  return file_sp->FindLinesMatchingRegex(regex, start_line, end_line,

                                         match_lines);

}

SourceManager::File::File(const FileSpec &file_spec,

                          lldb::DebuggerSP debugger_sp)

    : m_file_spec_orig(file_spec), m_file_spec(), m_mod_time(),

      m_debugger_wp(debugger_sp), m_target_wp(TargetSP()) {

  CommonInitializer(file_spec, {});

}

SourceManager::File::File(const FileSpec &file_spec, TargetSP target_sp)

    : m_file_spec_orig(file_spec), m_file_spec(), m_mod_time(),

      m_debugger_wp(target_sp ? target_sp->GetDebugger().shared_from_this()

                              : 
DebuggerSP()0
),

      m_target_wp(target_sp) {

  CommonInitializer(file_spec, target_sp);

}

void SourceManager::File::CommonInitializer(const FileSpec &file_spec,

                                            TargetSP target_sp) {

  // Set the file and update the modification time.

  SetFileSpec(file_spec);

  // Always update the source map modification ID if we have a target.

  if (target_sp)

    m_source_map_mod_id = target_sp->GetSourcePathMap().GetModificationID();

  // File doesn't exist.

  if (m_mod_time == llvm::sys::TimePoint<>()) {

    if (target_sp) {

      // If this is just a file name, try finding it in the target.

      if (!file_spec.GetDirectory() && 
file_spec.GetFilename()0
) {

        bool check_inlines = false;

        SymbolContextList sc_list;

        size_t num_matches =

            target_sp->GetImages().ResolveSymbolContextForFilePath(

                file_spec.GetFilename().AsCString(), 0, check_inlines,

                SymbolContextItem(eSymbolContextModule |

                                  eSymbolContextCompUnit),

                sc_list);

        bool got_multiple = false;

        if (num_matches != 0) {

          if (num_matches > 1) {

            CompileUnit *test_cu = nullptr;

            for (const SymbolContext &sc : sc_list) {

              if (sc.comp_unit) {

                if (test_cu) {

                  if (test_cu != sc.comp_unit)

                    got_multiple = true;

                  break;

                } else

                  test_cu = sc.comp_unit;

              }

            }

          }

          if (!got_multiple) {

            SymbolContext sc;

            sc_list.GetContextAtIndex(0, sc);

            if (sc.comp_unit)

              SetFileSpec(sc.comp_unit->GetPrimaryFile());

          }

        }

      }

      // Try remapping the file if it doesn't exist.

      if (!FileSystem::Instance().Exists(m_file_spec)) {

        // Check target specific source remappings (i.e., the

        // target.source-map setting), then fall back to the module

        // specific remapping (i.e., the .dSYM remapping dictionary).

        auto remapped = target_sp->GetSourcePathMap().FindFile(m_file_spec);

        if (!remapped) {

          FileSpec new_spec;

          if (target_sp->GetImages().FindSourceFile(m_file_spec, new_spec))

            remapped = new_spec;

        }

        if (remapped)

          SetFileSpec(*remapped);

      }

    }

  }

  // If the file exists, read in the data.

  if (m_mod_time != llvm::sys::TimePoint<>())

    m_data_sp = FileSystem::Instance().CreateDataBuffer(m_file_spec);

}

void SourceManager::File::SetFileSpec(FileSpec file_spec) {

  resolve_tilde(file_spec);

  m_file_spec = std::move(file_spec);

  m_mod_time = FileSystem::Instance().GetModificationTime(m_file_spec);

}

uint32_t SourceManager::File::GetLineOffset(uint32_t line) {

  if (line == 0)

    return UINT32_MAX;

  if (line == 1)

    return 0;

  if (CalculateLineOffsets(line)) {

    if (line < m_offsets.size())

      return m_offsets[line - 1]; // yes we want "line - 1" in the index

  }

  return UINT32_MAX;

}

uint32_t SourceManager::File::GetNumLines() {

  CalculateLineOffsets();

  return m_offsets.size();

}

const char *SourceManager::File::PeekLineData(uint32_t line) {

  if (!LineIsValid(line))

    return nullptr;

  size_t line_offset = GetLineOffset(line);

  if (line_offset < m_data_sp->GetByteSize())

    return (const char *)m_data_sp->GetBytes() + line_offset;

  return nullptr;

}

uint32_t SourceManager::File::GetLineLength(uint32_t line,

                                            bool include_newline_chars) {

  if (!LineIsValid(line))

    return false;

  size_t start_offset = GetLineOffset(line);

  size_t end_offset = GetLineOffset(line + 1);

  if (end_offset == UINT32_MAX)

    end_offset = m_data_sp->GetByteSize();

  if (end_offset > start_offset) {

    uint32_t length = end_offset - start_offset;

    if (!include_newline_chars) {

      const char *line_start =

          (const char *)m_data_sp->GetBytes() + start_offset;

      while (length > 0) {

        const char last_char = line_start[length - 1];

        if ((last_char == '\r') || (last_char == '\n'))

          --length;

        else

          break;

      }

    }

    return length;

  }

  return 0;

}

bool SourceManager::File::LineIsValid(uint32_t line) {

  if (line == 0)

    return false;

  if (CalculateLineOffsets(line))

    return line < m_offsets.size();

  return false;

}

bool SourceManager::File::ModificationTimeIsStale() const {

  // TODO: use host API to sign up for file modifications to anything in our

  // source cache and only update when we determine a file has been updated.

  // For now we check each time we want to display info for the file.

  auto curr_mod_time = FileSystem::Instance().GetModificationTime(m_file_spec);

  return curr_mod_time != llvm::sys::TimePoint<>() &&

         m_mod_time != curr_mod_time;

}

bool SourceManager::File::PathRemappingIsStale() const {

  if (TargetSP target_sp = m_target_wp.lock())

    return GetSourceMapModificationID() !=

           target_sp->GetSourcePathMap().GetModificationID();

  return false;

}

size_t SourceManager::File::DisplaySourceLines(uint32_t line,

                                               std::optional<size_t> column,

                                               uint32_t context_before,

                                               uint32_t context_after,

                                               Stream *s) {

  // Nothing to write if there's no stream.

  if (!s)

    return 0;

  // Sanity check m_data_sp before proceeding.

  if (!m_data_sp)

    return 0;

  size_t bytes_written = s->GetWrittenBytes();

  auto debugger_sp = m_debugger_wp.lock();

  HighlightStyle style;

  // Use the default Vim style if source highlighting is enabled.

  if (should_highlight_source(debugger_sp))

    style = HighlightStyle::MakeVimStyle();

  // If we should mark the stop column with color codes, then copy the prefix

  // and suffix to our color style.

  if (should_show_stop_column_with_ansi(debugger_sp))

    style.selected.Set(debugger_sp->GetStopShowColumnAnsiPrefix(),

                       debugger_sp->GetStopShowColumnAnsiSuffix());

  HighlighterManager mgr;

  std::string path = GetFileSpec().GetPath(/*denormalize*/ false);

  // FIXME: Find a way to get the definitive language this file was written in

  // and pass it to the highlighter.

  const auto &h = mgr.getHighlighterFor(lldb::eLanguageTypeUnknown, path);

  const uint32_t start_line =

      line <= context_before ? 
10
 : line - context_before;

  const uint32_t start_line_offset = GetLineOffset(start_line);

  if (start_line_offset != UINT32_MAX) {

    const uint32_t end_line = line + context_after;

    uint32_t end_line_offset = GetLineOffset(end_line + 1);

    if (end_line_offset == UINT32_MAX)

      end_line_offset = m_data_sp->GetByteSize();

    assert(start_line_offset <= end_line_offset);

    if (start_line_offset < end_line_offset) {

      size_t count = end_line_offset - start_line_offset;

      const uint8_t *cstr = m_data_sp->GetBytes() + start_line_offset;

      auto ref = llvm::StringRef(reinterpret_cast<const char *>(cstr), count);

      h.Highlight(style, ref, column, "", *s);

      // Ensure we get an end of line character one way or another.

      if (!is_newline_char(ref.back()))

        s->EOL();

    }

  }

  return s->GetWrittenBytes() - bytes_written;

}

void SourceManager::File::FindLinesMatchingRegex(

    RegularExpression &regex, uint32_t start_line, uint32_t end_line,

    std::vector<uint32_t> &match_lines) {

  match_lines.clear();

  if (!LineIsValid(start_line) ||

      (end_line != UINT32_MAX && 
!LineIsValid(end_line)0
))

    return;

  if (start_line > end_line)

    return;

  
for (uint32_t line_no = start_line; 1.04k
line_no < end_line; 
line_no++63.3k
) {

    std::string buffer;

    if (!GetLine(line_no, buffer))

      break;

    if (regex.Execute(buffer)) {

      match_lines.push_back(line_no);

    }

  }

}

bool lldb_private::operator==(const SourceManager::File &lhs,

                              const SourceManager::File &rhs) {

  if (lhs.m_file_spec != rhs.m_file_spec)

    return false;

  return lhs.m_mod_time == rhs.m_mod_time;

}

bool SourceManager::File::CalculateLineOffsets(uint32_t line) {

  line =

      UINT32_MAX; // TODO: take this line out when we support partial indexing

  if (line == UINT32_MAX) {

    // Already done?

    if (!m_offsets.empty() && 
m_offsets[0] == UINT32_MAX224k
)

      return true;

    if (m_offsets.empty()) {

      if (m_data_sp.get() == nullptr)

        return false;

      const char *start = (const char *)m_data_sp->GetBytes();

      if (start) {

        const char *end = start + m_data_sp->GetByteSize();

        // Calculate all line offsets from scratch

        // Push a 1 at index zero to indicate the file has been completely

        // indexed.

        m_offsets.push_back(UINT32_MAX);

        const char *s;

        for (s = start; s < end; 
++s3.32M
) {

          char curr_ch = *s;

          if (is_newline_char(curr_ch)) {

            if (s + 1 < end) {

              char next_ch = s[1];

              if (is_newline_char(next_ch)) {

                if (curr_ch != next_ch)

                  ++s;

              }

            }

            m_offsets.push_back(s + 1 - start);

          }

        }

        if (!m_offsets.empty()) {

          if (m_offsets.back() < size_t(end - start))

            m_offsets.push_back(end - start);

        }

        return true;

      }

    } else {

      // Some lines have been populated, start where we last left off

      assert("Not implemented yet" && false);

    }

  } else {

    // Calculate all line offsets up to "line"

    assert("Not implemented yet" && false);

  }

  return false;

}

bool SourceManager::File::GetLine(uint32_t line_no, std::string &buffer) {

  if (!LineIsValid(line_no))

    return false;

  size_t start_offset = GetLineOffset(line_no);

  size_t end_offset = GetLineOffset(line_no + 1);

  if (end_offset == UINT32_MAX) {

    end_offset = m_data_sp->GetByteSize();

  }

  buffer.assign((const char *)m_data_sp->GetBytes() + start_offset,

                end_offset - start_offset);

  return true;

}

void SourceManager::SourceFileCache::AddSourceFile(const FileSpec &file_spec,

                                                   FileSP file_sp) {

  llvm::sys::ScopedWriter guard(m_mutex);

  assert(file_sp && "invalid FileSP");

  AddSourceFileImpl(file_spec, file_sp);

  const FileSpec &resolved_file_spec = file_sp->GetFileSpec();

  if (file_spec != resolved_file_spec)

    AddSourceFileImpl(file_sp->GetFileSpec(), file_sp);

}

void SourceManager::SourceFileCache::RemoveSourceFile(const FileSP &file_sp) {

  llvm::sys::ScopedWriter guard(m_mutex);

  assert(file_sp && "invalid FileSP");

  // Iterate over all the elements in the cache.

  // This is expensive but a relatively uncommon operation.

  auto it = m_file_cache.begin();

  while (it != m_file_cache.end()) {

    if (it->second == file_sp)

      it = m_file_cache.erase(it);

    else

      it++;

  }

}

void SourceManager::SourceFileCache::AddSourceFileImpl(

    const FileSpec &file_spec, FileSP file_sp) {

  FileCache::iterator pos = m_file_cache.find(file_spec);

  if (pos == m_file_cache.end()) {

    m_file_cache[file_spec] = file_sp;

  } else {

    if (file_sp != pos->second)

      m_file_cache[file_spec] = file_sp;

  }

}

SourceManager::FileSP SourceManager::SourceFileCache::FindSourceFile(

    const FileSpec &file_spec) const {

  llvm::sys::ScopedReader guard(m_mutex);

  FileCache::const_iterator pos = m_file_cache.find(file_spec);

  if (pos != m_file_cache.end())

    return pos->second;

  return {};

}

void SourceManager::SourceFileCache::Dump(Stream &stream) const {

  stream << "Modification time   Lines    Path\n";

  stream << "------------------- -------- --------------------------------\n";

  for (auto &entry : m_file_cache) {

    if (!entry.second)

      continue;

    FileSP file = entry.second;

    stream.Format("{0:%Y-%m-%d %H:%M:%S} {1,8:d} {2}\n", file->GetTimestamp(),

                  file->GetNumLines(), entry.first.GetPath());

  }

}