src/libstrongswan/settings/settings_lexer.l

   1 %{
   2 /*
   3  * Copyright (C) 2014 Tobias Brunner
   4  * Hochschule fuer Technik Rapperswil
   5  *
   6  * This program is free software; you can redistribute it and/or modify it
   7  * under the terms of the GNU General Public License as published by the
   8  * Free Software Foundation; either version 2 of the License, or (at your
   9  * option) any later version.  See <http://www.fsf.org/copyleft/gpl.txt>.
  10  *
  11  * This program is distributed in the hope that it will be useful, but
  12  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  13  * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * for more details.
  15  */
  16
  17 #include <utils/parser_helper.h>
  18
  19 #include "settings_parser.h"
  20
  21 bool settings_parser_open_next_file(parser_helper_t *ctx);
  22
  23 static void include_files(parser_helper_t *ctx);
  24
  25 %}
  26 %option debug
  27 %option perf-report
  28
  29 %option warn
  30
  31 /* use start conditions stack */
  32 %option stack
  33
  34 /* do not declare unneded functions */
  35 %option noinput noyywrap
  36
  37 /* don't use global variables, and interact properly with bison */
  38 %option reentrant bison-bridge
  39
  40 /* maintain the line number */
  41 %option yylineno
  42
  43 /* don't generate a default rule */
  44 %option nodefault
  45
  46 /* prefix function/variable declarations */
  47 %option prefix="settings_parser_"
  48 /* don't change the name of the output file otherwise autotools has issues */
  49 %option outfile="lex.yy.c"
  50
  51 /* type of our extra data */
  52 %option extra-type="parser_helper_t*"
  53
  54 /* state used to scan include file patterns */
  55 %x inc
  56 /* state used to scan quoted strings */
  57 %x str
  58
  59 %%
  60
  61 [\t ]*#[^\n]*                   /* eat comments */
  62 [\t ]+                                  /* eat whitespace */
  63 \n|#.*\n                                return NEWLINE; /* also eats comments at the end of a line */
  64
  65 "{"                                             |
  66 "}"                                             |
  67 "="                                             return yytext[0];
  68
  69 "include"[\t ]+/[^=]    {
  70         yyextra->string_init(yyextra);
  71         yy_push_state(inc, yyscanner);
  72 }
  73
  74 "\""                                    {
  75         yyextra->string_init(yyextra);
  76         yy_push_state(str, yyscanner);
  77 }
  78
  79 [^#{}="\n\t ]+                  {
  80         yylval->s = strdup(yytext);
  81         return NAME;
  82 }
  83
  84 <inc>{
  85         /* we allow all characters except #, } and spaces, they can be escaped */
  86         <<EOF>>                         |
  87         \n|#.*\n                        |
  88         [\t ]                           {
  89                 if (*yytext && yytext[strlen(yytext) - 1] == '\n')
  90                 {       /* put the newline back to fix the line numbers */
  91                         unput('\n');
  92                         yy_set_bol(0);
  93                 }
  94                 include_files(yyextra);
  95                 yy_pop_state(yyscanner);
  96         }
  97         "\""                            {       /* string include */
  98                 yy_push_state(str, yyscanner);
  99         }
 100         \\                                      {
 101                 yyextra->string_add(yyextra, yytext);
 102         }
 103         \\["#} ]                        {
 104                 yyextra->string_add(yyextra, yytext+1);
 105         }
 106         [^"\\#}\n\t ]+ {
 107                 yyextra->string_add(yyextra, yytext);
 108         }
 109 }
 110
 111 <str>{
 112         "\""                            |
 113         <<EOF>>                         |
 114         \n                                      |
 115         \\                                      {
 116                 if (!streq(yytext, "\""))
 117                 {
 118                         if (streq(yytext, "\n"))
 119                         {       /* put the newline back to fix the line numbers */
 120                                 unput('\n');
 121                                 yy_set_bol(0);
 122                         }
 123                         PARSER_DBG1(yyextra, "unterminated string detected");
 124                 }
 125                 if (yy_top_state(yyscanner) == inc)
 126                 {       /* string include */
 127                         include_files(yyextra);
 128                         yy_pop_state(yyscanner);
 129                         yy_pop_state(yyscanner);
 130                 }
 131                 else
 132                 {
 133                         yy_pop_state(yyscanner);
 134                         yylval->s = yyextra->string_get(yyextra);
 135                         return STRING;
 136                 }
 137         }
 138         \\n     yyextra->string_add(yyextra, "\n");
 139         \\r     yyextra->string_add(yyextra, "\r");
 140         \\t     yyextra->string_add(yyextra, "\t");
 141         \\b     yyextra->string_add(yyextra, "\b");
 142         \\f     yyextra->string_add(yyextra, "\f");
 143         \\(.|\n)                        {
 144                 yyextra->string_add(yyextra, yytext+1);
 145         }
 146         [^\\\n"]+                       {
 147                 yyextra->string_add(yyextra, yytext);
 148         }
 149 }
 150
 151 <<EOF>>                                 {
 152         settings_parser_pop_buffer_state(yyscanner);
 153         if (!settings_parser_open_next_file(yyextra) && !YY_CURRENT_BUFFER)
 154         {
 155                 yyterminate();
 156         }
 157 }
 158
 159 %%
 160
 161 /**
 162  * Open the next file, if any is queued and readable, otherwise returns FALSE.
 163  */
 164 bool settings_parser_open_next_file(parser_helper_t *ctx)
 165 {
 166         parser_helper_file_t *file;
 167
 168         file = ctx->file_next(ctx);
 169         if (!file)
 170         {
 171                 return FALSE;
 172         }
 173
 174         settings_parser_set_in(file->file, ctx->scanner);
 175         settings_parser_push_buffer_state(
 176                         settings_parser__create_buffer(file->file, YY_BUF_SIZE,
 177                                                                                    ctx->scanner), ctx->scanner);
 178         return TRUE;
 179 }
 180
 181 /**
 182  * Assumes that the file pattern to include is currently stored as string on
 183  * the helper object.
 184  */
 185 static void include_files(parser_helper_t *ctx)
 186 {
 187         char *pattern = ctx->string_get(ctx);
 188
 189         ctx->file_include(ctx, pattern);
 190         free(pattern);
 191
 192         settings_parser_open_next_file(ctx);
 193 }