src/lexer.c

   1 /*!@file
   2   \brief   lexical analyzer implementation for APC
   3   \details The lexer manages two FIFO stacks.  One for maintaining tokens, the
   4            other for maintaining a list of files to be scanned.  During
   5            execution, the lexer will return a token from its token queue if any
   6            are present.  If not, the lexer will will pop an element from its
   7            file queue to 'scanner' to be tokenized.  If the file queue is empty,
   8            the lexer will instead call 'parsedir' to traverse the directory tree
   9            and tokenize the results.  If 'parsedir' does not generate any new
  10            tokens, we are done.
  11   \author  Jordan Lavatai
  12   \date    Aug 2016
  13   ----------------------------------------------------------------------------*/
  14 /* Standard */
  15 #include <stdio.h>
  16 #include <string.h>
  17 #include <stdint.h>
  18 #include <errno.h>
  19 /* Posix */
  20 #include <unistd.h>
  21 #include <unitypes.h>
  22 #include <unistr.h>
  23 #include <uniconv.h>
  24 #include <uniname.h>
  25 #include <unistdio.h>
  26 #include <stdlib.h>
  27 #include <dirent.h>
  28 /* Local */
  29 #include "apc.h"
  30 #include "parser.tab.h"
  31 /* Public */
  32 int lexer_lexfile(uint8_t const*);
  33 /* Private */
  34 extern //lexer.rl
  35 int lexer_lexstring(uint8_t const*, int);
  36 extern //scanner.c
  37 yypstate* apc_pstate;
  38 extern //scanner.c
  39 yycstate* apc_cstate;
  40 #define PUSHTOK(T,L) yypush_parse(apc_pstate, T, L, apc_cstate)
  41
  42 /* Lexical analysis of a file
  43    Strips a filename to its base name, then sends it to lexer_lexstring before
  44    pushing a PATH token with the filename
  45    Returns the number of tokens pushed to the parser.
  46 */
  47 int lexer_lexfile
  48 ( uint8_t const* filename )
  49 { uint8_t const* last_period,* iter;
  50   int            ntok;
  51   union YYSTYPE tok_val;
  52   last_period = NULL;
  53   for (iter = filename; *iter; iter++)
  54     if (*iter ==  '.')
  55       last_period = iter;
  56   if (last_period)
  57     { ntok = lexer_lexstring(filename, (int)(last_period - filename));
  58       tok_val.str = filename;
  59       PUSHTOK(PATH,&tok_val);
  60       return ntok + 1;
  61     }
  62   return lexer_lexstring(filename, (int)(iter - filename));
  63 }