hanchenye-llvm-project/lldb/source/Core/SourceManager.cpp

//===-- SourceManager.cpp ---------------------------------------*- C++ -*-===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//

#include "lldb/lldb-python.h"

#include "lldb/Core/SourceManager.h"

// C Includes
// C++ Includes
// Other libraries and framework includes
// Project includes
#include "lldb/Core/DataBuffer.h"
#include "lldb/Core/Debugger.h"
#include "lldb/Core/Module.h"
#include "lldb/Core/Stream.h"
#include "lldb/Symbol/ClangNamespaceDecl.h"
#include "lldb/Symbol/CompileUnit.h"
#include "lldb/Symbol/Function.h"
#include "lldb/Symbol/SymbolContext.h"
#include "lldb/Target/Target.h"

using namespace lldb;
using namespace lldb_private;


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


//----------------------------------------------------------------------
// SourceManager constructor
//----------------------------------------------------------------------
SourceManager::SourceManager(const TargetSP &target_sp) :
    m_last_file_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_file_sp (),
    m_last_line (0),
    m_last_count (0),
    m_default_set(false),
    m_target_wp (),
    m_debugger_wp (debugger_sp)
{
}

//----------------------------------------------------------------------
// Destructor
//----------------------------------------------------------------------
SourceManager::~SourceManager()
{
}

SourceManager::FileSP
SourceManager::GetFile (const FileSpec &file_spec)
{
    bool same_as_previous = m_last_file_sp && m_last_file_sp->FileSpecMatches (file_spec);

    DebuggerSP debugger_sp (m_debugger_wp.lock());
    FileSP file_sp;
    if (same_as_previous)
        file_sp = m_last_file_sp;
    else if (debugger_sp)
        file_sp = debugger_sp->GetSourceFileCache().FindSourceFile (file_spec);
    
    TargetSP target_sp (m_target_wp.lock());

    // It the target source path map has been updated, get this file again so we
    // can successfully remap the source file
    if (target_sp && file_sp && file_sp->GetSourceMapModificationID() != target_sp->GetSourcePathMap().GetModificationID())
        file_sp.reset();

    // If file_sp is no good or it points to a non-existent file, reset it.
    if (!file_sp || !file_sp->GetFileSpec().Exists())
    {
        file_sp.reset (new File (file_spec, target_sp.get()));

        if (debugger_sp)
            debugger_sp->GetSourceFileCache().AddSourceFile(file_sp);
    }
    return file_sp;
}

size_t
SourceManager::DisplaySourceLinesWithLineNumbersUsingLastFile (uint32_t start_line,
                                                               uint32_t count,
                                                               uint32_t curr_line,
                                                               const char* current_line_cstr,
                                                               Stream *s,
                                                               const SymbolContextList *bp_locs)
{
    if (count == 0)
        return 0;
    size_t return_value = 0;
    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 (m_last_file_sp.get())
    {
        const uint32_t end_line = start_line + count - 1;
        for (uint32_t line = start_line; line <= end_line; ++line)
        {
            if (!m_last_file_sp->LineIsValid (line))
            {
                m_last_line = UINT32_MAX;
                break;
            }

            char prefix[32] = "";
            if (bp_locs)
            {
                uint32_t bp_count = bp_locs->NumLineEntriesWithLine (line);
                
                if (bp_count > 0)
                    ::snprintf (prefix, sizeof (prefix), "[%u] ", bp_count);
                else
                    ::snprintf (prefix, sizeof (prefix), "    ");
            }

            return_value += s->Printf("%s%2.2s %-4u\t", 
                                      prefix,
                                      line == curr_line ? current_line_cstr : "",
                                      line);
            size_t this_line_size = m_last_file_sp->DisplaySourceLines (line, 0, 0, s);
            if (this_line_size == 0)
            {
                m_last_line = UINT32_MAX;
                break;
            }
            else
                return_value += this_line_size;
        }
    }
    return return_value;
}

size_t
SourceManager::DisplaySourceLinesWithLineNumbers
(
    const FileSpec &file_spec,
    uint32_t line,
    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;
    
    if (m_last_file_sp.get() != file_sp.get())
    {
        if (line == 0)
            m_last_line = 0;
        m_last_file_sp = file_sp;
    }
    return DisplaySourceLinesWithLineNumbersUsingLastFile (start_line, count, line, 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.
    const bool have_default_file_line = m_last_file_sp && m_last_line > 0;
    if (!m_default_set)
    {
        FileSpec tmp_spec;
        uint32_t tmp_line;
        GetDefaultFileAndLine(tmp_spec, tmp_line);
    }
    
    if (m_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;
        
        return DisplaySourceLinesWithLineNumbersUsingLastFile (m_last_line, m_last_count, UINT32_MAX, "", s, bp_locs);
    }
    return 0;
}

bool
SourceManager::SetDefaultFileAndLine (const FileSpec &file_spec, uint32_t line)
{
    FileSP old_file_sp = m_last_file_sp;
    m_last_file_sp = GetFile (file_spec);
    
    m_default_set = true;
    if (m_last_file_sp)
    {
        m_last_line = line;
        return true;
    }
    else
    {
        m_last_file_sp = old_file_sp;
        return false;
    }
}

bool 
SourceManager::GetDefaultFileAndLine (FileSpec &file_spec, uint32_t &line)
{
    if (m_last_file_sp)
    {
        file_spec = m_last_file_sp->GetFileSpec();
        line = m_last_line;
        return true;
    }
    else if (!m_default_set)
    {
        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");
                bool symbols_okay = false;  // Force it to be a debug symbol.
                bool inlines_okay = true;
                bool append = false;
                size_t num_matches = executable_ptr->FindFunctions (main_name,
                                                                    NULL,
                                                                    lldb::eFunctionNameTypeBase,
                                                                    inlines_okay,
                                                                    symbols_okay,
                                                                    append,
                                                                    sc_list);
                for (size_t idx = 0; idx < num_matches; idx++)
                {
                    SymbolContext sc;
                    sc_list.GetContextAtIndex(idx, sc);
                    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_sp->GetFileSpec();
                            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, Target *target) :
    m_file_spec_orig (file_spec),
    m_file_spec(file_spec),
    m_mod_time (file_spec.GetModificationTime()),
    m_source_map_mod_id (0),
    m_data_sp(),
    m_offsets()
{
    if (!m_mod_time.IsValid())
    {
        if (target)
        {
            m_source_map_mod_id = target->GetSourcePathMap().GetModificationID();

            if (!file_spec.GetDirectory() && file_spec.GetFilename())
            {
                // If this is just a file name, lets see if we can find it in the target:
                bool check_inlines = false;
                SymbolContextList sc_list;
                size_t num_matches = target->GetImages().ResolveSymbolContextForFilePath (file_spec.GetFilename().AsCString(),
                                                                                          0,
                                                                                          check_inlines,
                                                                                          lldb::eSymbolContextModule | lldb::eSymbolContextCompUnit,
                                                                                          sc_list);
                bool got_multiple = false;
                if (num_matches != 0)
                {
                    if (num_matches > 1)
                    {
                        SymbolContext sc;
                        FileSpec *test_cu_spec = NULL;

                        for (unsigned i = 0; i < num_matches; i++)
                        {
                            sc_list.GetContextAtIndex(i, sc);
                            if (sc.comp_unit)
                            {
                                if (test_cu_spec)
                                {
                                    if (test_cu_spec != static_cast<FileSpec *> (sc.comp_unit))
                                        got_multiple = true;
                                        break;
                                }
                                else
                                    test_cu_spec = sc.comp_unit;
                            }
                        }
                    }
                    if (!got_multiple)
                    {
                        SymbolContext sc;
                        sc_list.GetContextAtIndex (0, sc);
                        m_file_spec = sc.comp_unit;
                        m_mod_time = m_file_spec.GetModificationTime();
                    }
                }
            }
            // Try remapping if m_file_spec does not correspond to an existing file.
            if (!m_file_spec.Exists())
            {
                FileSpec new_file_spec;
                // Check target specific source remappings first, then fall back to
                // modules objects can have individual path remappings that were detected
                // when the debug info for a module was found.
                // then
                if (target->GetSourcePathMap().FindFile (m_file_spec, new_file_spec) ||
                    target->GetImages().FindSourceFile (m_file_spec, new_file_spec))
                {
                    m_file_spec = new_file_spec;
                    m_mod_time = m_file_spec.GetModificationTime();
                }
            }
        }
    }
    
    if (m_mod_time.IsValid())
        m_data_sp = m_file_spec.ReadFileContents ();
}

SourceManager::File::~File()
{
}

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 NULL;
    
    size_t line_offset = GetLineOffset (line);
    if (line_offset < m_data_sp->GetByteSize())
        return (const char *)m_data_sp->GetBytes() + line_offset;
    return NULL;
}

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 == false)
        {
            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;
}

size_t
SourceManager::File::DisplaySourceLines (uint32_t line, uint32_t context_before, uint32_t context_after, Stream *s)
{
    // 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.
    TimeValue curr_mod_time (m_file_spec.GetModificationTime());

    if (curr_mod_time.IsValid() && m_mod_time != curr_mod_time)
    {
        m_mod_time = curr_mod_time;
        m_data_sp = m_file_spec.ReadFileContents ();
        m_offsets.clear();
    }

    // Sanity check m_data_sp before proceeding.
    if (!m_data_sp)
        return 0;

    const uint32_t start_line = line <= context_before ? 1 : 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);
        size_t bytes_written = 0;
        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;
            bytes_written = s->Write(cstr, count);
            if (!is_newline_char(cstr[count-1]))
                bytes_written += s->EOL();
        }
        return bytes_written;
    }
    return 0;
}

void
SourceManager::File::FindLinesMatchingRegex (RegularExpression& regex, uint32_t start_line, uint32_t end_line, std::vector<uint32_t> &match_lines)
{
    TimeValue curr_mod_time (m_file_spec.GetModificationTime());
    if (m_mod_time != curr_mod_time)
    {
        m_mod_time = curr_mod_time;
        m_data_sp = m_file_spec.ReadFileContents ();
        m_offsets.clear();
    }
    
    match_lines.clear();
    
    if (!LineIsValid(start_line) || (end_line != UINT32_MAX && !LineIsValid(end_line)))
        return;
    if (start_line > end_line)
        return;
        
    for (uint32_t line_no = start_line; line_no < end_line; line_no++)
    {
        std::string buffer;
        if (!GetLine (line_no, buffer))
            break;
        if (regex.Execute(buffer.c_str()))
        {
            match_lines.push_back(line_no);
        }
    }
}

bool
SourceManager::File::FileSpecMatches (const FileSpec &file_spec)
{
    return FileSpec::Equal (m_file_spec, file_spec, false);
}

bool
lldb_private::operator== (const SourceManager::File &lhs, const SourceManager::File &rhs)
{
    if (lhs.m_file_spec == rhs.m_file_spec)
    {
        if (lhs.m_mod_time.IsValid())
        {
            if (rhs.m_mod_time.IsValid())
                return lhs.m_mod_time == rhs.m_mod_time;
            else
                return false;
        }
        else if (rhs.m_mod_time.IsValid())
            return false;
        else
            return true;
    }
    else
        return false;
}

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_MAX)
            return true;

        if (m_offsets.empty())
        {
            if (m_data_sp.get() == NULL)
                return false;

            const char *start = (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; ++s)
                {
                    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() < 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" == NULL);
        }

    }
    else
    {
        // Calculate all line offsets up to "line"
        assert("Not implemented yet" == NULL);
    }
    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((char *) m_data_sp->GetBytes() + start_offset, end_offset - start_offset);
    
    return true;
}

void 
SourceManager::SourceFileCache::AddSourceFile (const FileSP &file_sp)
{
    FileSpec file_spec;
    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
{
    FileSP file_sp;
    FileCache::const_iterator pos = m_file_cache.find(file_spec);
    if (pos != m_file_cache.end())
        file_sp = pos->second;
    return file_sp;
}