lib/includable-lexer.cc

   1 /*
   2   includable-lexer.cc -- implement Includable_lexer
   3
   4   source file of the LilyPond music typesetter
   5
   6   (c) 1997 Han-Wen Nienhuys <hanwen@stack.nl>
   7 */
   8 #include "includable-lexer.hh"
   9 #include "source-file.hh"
  10 #include "source.hh"
  11
  12 #ifndef YY_BUF_SIZE
  13 #define YY_BUF_SIZE 16384
  14 #endif
  15
  16 Includable_lexer::Includable_lexer ()
  17 {
  18   yy_current_buffer = 0;
  19 }
  20
  21 /** set the  new input to s, remember old file.
  22 */
  23 void
  24 Includable_lexer::new_input (String s, Sources  * global_sources)
  25 {
  26   Source_file * sl = global_sources->get_file_l (s);
  27   if (!sl)
  28     {
  29       String msg =_ ("Can't find file `") + s+ "'";
  30       LexerError (msg.ch_C ());
  31       return;
  32     }
  33
  34
  35   char_count_stack_.push (0);
  36   if (yy_current_buffer)
  37     state_stack_.push (yy_current_buffer);
  38   cout << "[" << s<<flush;
  39   include_stack_.push (sl);
  40
  41   /*
  42     ugh. We'd want to create a buffer from the bytes directly.
  43
  44     Whoops. The size argument to yy_create_buffer is not the
  45     filelength but a BUFFERSIZE. Maybe this is why reading stdin fucks up.
  46
  47     */
  48   yy_switch_to_buffer (yy_create_buffer (sl->istream_l (), YY_BUF_SIZE));
  49 }
  50
  51 /** pop the inputstack.  conceptually this is a destructor, but it
  52   does not destruct the Source_file that Includable_lexer::new_input creates.  */
  53 bool
  54 Includable_lexer::close_input ()
  55 {
  56   include_stack_.pop ();
  57   char_count_stack_.pop ();
  58   cout << "]"<<flush;
  59   yy_delete_buffer (yy_current_buffer);
  60   yy_current_buffer = 0;
  61   if (state_stack_.empty ())
  62     {
  63       return false;
  64     }
  65   else
  66       {
  67         yy_switch_to_buffer (state_stack_.pop ());
  68         return true;
  69       }
  70 }
  71
  72 char const*
  73 Includable_lexer::here_ch_C ()
  74 {
  75   if (include_stack_.empty ())
  76     return 0;
  77   return include_stack_.top ()->ch_C () + char_count_stack_.top ();
  78 }
  79
  80 Includable_lexer::~Includable_lexer ()
  81 {
  82   while (!include_stack_.empty ())
  83     {
  84       close_input ();
  85     }
  86 }
  87 /**
  88   Since we don't create the buffer state from the bytes directly, we
  89   don't know about the location of the lexer. Add this as a
  90   YY_USER_ACTION */
  91 void
  92 Includable_lexer::add_lexed_char (int count)
  93 {
  94   char_count_stack_.top () += count;
  95 }
  96
  97 Source_file*
  98 Includable_lexer::source_file_l () const
  99 {
 100   if (include_stack_.empty ())
 101     return 0;
 102   else
 103     return include_stack_.top ();
 104 }