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         LexerError("Can't find file `" + s+ "'");
  30         return;
  31       }
  32
  33
  34     char_count_stack_.push(0);
  35     if (yy_current_buffer)
  36         state_stack_.push(yy_current_buffer);
  37     cout << "[" << s<<flush;
  38     include_stack_.push(sl);
  39
  40     /*
  41       ugh. We'd want to create a buffer from the bytes directly.
  42
  43       Whoops. The size argument to yy_create_buffer is not the
  44       filelength but a BUFFERSIZE. Maybe this is why reading stdin fucks up.
  45
  46       Maybe this is also the reason why LilyPond sometimes crashed
  47       mysteriously in yy_create_buffer() with a libc-malloc error
  48
  49       */
  50     yy_switch_to_buffer(yy_create_buffer( sl->istream_l(), YY_BUF_SIZE ));
  51 }
  52
  53 /** pop the inputstack.  conceptually this is a destructor, but it
  54   does not destruct the Source_file that Includable_lexer::new_input creates.  */
  55 bool
  56 Includable_lexer::close_input()
  57 {
  58     include_stack_.pop();
  59     char_count_stack_.pop();
  60     cout << "]"<<flush;
  61     yy_delete_buffer(yy_current_buffer );
  62     yy_current_buffer = 0;
  63     if (state_stack_.empty())
  64       {
  65         return false;
  66     }else
  67       {
  68         yy_switch_to_buffer(state_stack_.pop());
  69         return true;
  70       }
  71 }
  72
  73 char const*
  74 Includable_lexer::here_ch_C()
  75 {
  76     if (include_stack_.empty())
  77         return 0;
  78     return include_stack_.top()->ch_C() + char_count_stack_.top();
  79 }
  80
  81 Includable_lexer::~Includable_lexer()
  82 {
  83     while (!include_stack_.empty())
  84       {
  85         close_input();
  86     };
  87 }
  88 /**
  89   Since we don't create the buffer state from the bytes directly, we
  90   don't know about the location of the lexer. Add this as a
  91   YY_USER_ACTION */
  92 void
  93 Includable_lexer::add_lexed_char(int count)
  94 {
  95     char_count_stack_.top() += count;
  96 }
  97
  98 Source_file*
  99 Includable_lexer::source_file_l()const
 100 {
 101     if (include_stack_.empty())
 102         return 0;
 103     else
 104         return include_stack_.top();
 105 }