gdb/source-cache.c

   1 /* Cache of styled source file text
   2    Copyright (C) 2018 Free Software Foundation, Inc.
   3
   4    This file is part of GDB.
   5
   6    This program is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 3 of the License, or
   9    (at your option) any later version.
  10
  11    This program is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  18
  19 #include "defs.h"
  20 #include "source-cache.h"
  21 #include "common/scoped_fd.h"
  22 #include "source.h"
  23 #include "cli/cli-style.h"
  24
  25 #ifdef HAVE_SOURCE_HIGHLIGHT
  26 #include <fstream>
  27 #include <sstream>
  28 #include <srchilite/sourcehighlight.h>
  29 #include <srchilite/langmap.h>
  30 #endif
  31
  32 /* The number of source files we'll cache.  */
  33
  34 #define MAX_ENTRIES 5
  35
  36 /* See source-cache.h.  */
  37
  38 source_cache g_source_cache;
  39
  40 /* See source-cache.h.  */
  41
  42 bool
  43 source_cache::get_plain_source_lines (struct symtab *s, int first_line,
  44                                       int last_line, std::string *lines)
  45 {
  46   scoped_fd desc (open_source_file (s));
  47   if (desc.get () < 0)
  48     return false;
  49
  50   if (s->line_charpos == 0)
  51     find_source_lines (s, desc.get ());
  52
  53   if (first_line < 1 || first_line > s->nlines || last_line < 1)
  54     return false;
  55
  56   if (lseek (desc.get (), s->line_charpos[first_line - 1], SEEK_SET) < 0)
  57     perror_with_name (symtab_to_filename_for_display (s));
  58
  59   int last_charpos;
  60   if (last_line >= s->nlines)
  61     {
  62       struct stat st;
  63
  64       if (fstat (desc.get (), &st) < 0)
  65         perror_with_name (symtab_to_filename_for_display (s));
  66       /* We could cache this in line_charpos... */
  67       last_charpos = st.st_size;
  68     }
  69   else
  70     last_charpos = s->line_charpos[last_line];
  71
  72   lines->resize (last_charpos - s->line_charpos[first_line - 1]);
  73   if (myread (desc.get (), &(*lines)[0], lines->size ()) < 0)
  74     perror_with_name (symtab_to_filename_for_display (s));
  75
  76   return true;
  77 }
  78
  79 /* See source-cache.h.  */
  80
  81 bool
  82 source_cache::extract_lines (const struct source_text &text, int first_line,
  83                              int last_line, std::string *lines)
  84 {
  85   int lineno = 1;
  86   std::string::size_type pos = 0;
  87   std::string::size_type first_pos = std::string::npos;
  88
  89   while (pos != std::string::npos && lineno <= last_line)
  90     {
  91       std::string::size_type new_pos = text.contents.find ('\n', pos);
  92
  93       if (lineno == first_line)
  94         first_pos = pos;
  95
  96       pos = new_pos;
  97       if (lineno == last_line || pos == std::string::npos)
  98         {
  99           if (pos == std::string::npos)
 100             pos = text.contents.size ();
 101           *lines = text.contents.substr (first_pos, pos - first_pos);
 102           return true;
 103         }
 104       ++lineno;
 105       ++pos;
 106     }
 107
 108   return false;
 109 }
 110
 111 /* Return the Source Highlight language name, given a gdb language
 112    LANG.  Returns NULL if the language is not known.  */
 113
 114 static const char *
 115 get_language_name (enum language lang)
 116 {
 117   switch (lang)
 118     {
 119     case language_c:
 120     case language_objc:
 121       return "c.lang";
 122
 123     case language_cplus:
 124       return "cpp.lang";
 125
 126     case language_d:
 127       return "d.lang";
 128
 129     case language_go:
 130       return "go.lang";
 131
 132     case language_fortran:
 133       return "fortran.lang";
 134
 135     case language_m2:
 136       /* Not handled by Source Highlight.  */
 137       break;
 138
 139     case language_asm:
 140       return "asm.lang";
 141
 142     case language_pascal:
 143       return "pascal.lang";
 144
 145     case language_opencl:
 146       /* Not handled by Source Highlight.  */
 147       break;
 148
 149     case language_rust:
 150       /* Not handled by Source Highlight.  */
 151       break;
 152
 153     case language_ada:
 154       return "ada.lang";
 155
 156     default:
 157       break;
 158     }
 159
 160   return nullptr;
 161 }
 162
 163 /* See source-cache.h.  */
 164
 165 bool
 166 source_cache::get_source_lines (struct symtab *s, int first_line,
 167                                 int last_line, std::string *lines)
 168 {
 169   if (first_line < 1 || last_line < 1 || first_line > last_line)
 170     return false;
 171
 172 #ifdef HAVE_SOURCE_HIGHLIGHT
 173   if (can_emit_style_escape (gdb_stdout))
 174     {
 175       const char *fullname = symtab_to_fullname (s);
 176
 177       for (const auto &item : m_source_map)
 178         {
 179           if (item.fullname == fullname)
 180             return extract_lines (item, first_line, last_line, lines);
 181         }
 182
 183       const char *lang_name = get_language_name (SYMTAB_LANGUAGE (s));
 184       if (lang_name != nullptr)
 185         {
 186           std::ifstream input (fullname);
 187           if (input.is_open ())
 188             {
 189               srchilite::SourceHighlight highlighter ("esc.outlang");
 190               highlighter.setStyleFile("esc.style");
 191
 192               std::ostringstream output;
 193               highlighter.highlight (input, output, lang_name, fullname);
 194
 195               source_text result = { fullname, output.str () };
 196               m_source_map.push_back (std::move (result));
 197
 198               if (m_source_map.size () > MAX_ENTRIES)
 199                 m_source_map.erase (m_source_map.begin ());
 200
 201               return extract_lines (m_source_map.back (), first_line,
 202                                     last_line, lines);
 203             }
 204         }
 205     }
 206 #endif /* HAVE_SOURCE_HIGHLIGHT */
 207
 208   return get_plain_source_lines (s, first_line, last_line, lines);
 209 }