yyalloc
void *yyalloc (yy_size_t );
b = (YY_BUFFER_STATE) yyalloc(sizeof( struct yy_buffer_state ) );
b->yy_ch_buf = (char *) yyalloc(b->yy_buf_size + 2 );
(yy_buffer_stack) = (struct yy_buffer_state**)yyalloc
b = (YY_BUFFER_STATE) yyalloc(sizeof( struct yy_buffer_state ) );
buf = (char *) yyalloc(n );