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   1 /* icalparse.y -- icalendar (RFC 5545) parser
   2  *
   3  * This code is Copyright (c) 2014, by the authors of nmh.  See the
   4  * COPYRIGHT file in the root directory of the nmh distribution for
   5  * complete copyright information.
   6  */
   7
   8 %{
   9     /*
  10      * Use these yy* #defines, instead of the -p command line
  11      * option, to allow multiple parsers in a program.  yyval
  12      * is generated by Solaris yacc and is of type YYSTYPE.
  13      * All other yy* symbols are data of a built-in type and
  14      * are initialized by yyparse(), so they can be shared
  15      * between different parsers.
  16      */
  17 #define yydebug icaldebug
  18 #define yyerror icalerror
  19 #define yylex   icallex
  20 #define yylval  icallval
  21 #define yyval   icalval
  22 #define yyparse icalparse
  23 #define YYDEBUG 1
  24 #define YYERROR_DEBUG
  25 #define YYERROR_VERBOSE
  26 #define YY_NO_LEAKS
  27
  28     /*
  29      * To quiet compile warnings with Solaris yacc:
  30 #ifdef sun
  31 # define lint 1
  32 # undef YYDEBUG
  33 #endif
  34     */
  35
  36 #include "h/mh.h"
  37 #include "h/icalendar.h"
  38 #include "h/utils.h"
  39
  40 static char *append (contentline *, const char *, const size_t);
  41 static void new_content_line (contentline **);
  42 static void new_vevent (vevent *);
  43 static void free_param_names (param_list *);
  44 static void free_param_values (value_list *);
  45 static int icalerror (const char *);
  46 %}
  47
  48 %token ICAL_NAME ICAL_COLON ICAL_VALUE ICAL_CRLF ICAL_SEMICOLON
  49 %token ICAL_PARAM_NAME ICAL_EQUAL ICAL_PARAM_VALUE ICAL_COMMA
  50
  51 %start contentline_list
  52
  53 %%
  54
  55     /* Instead of rigorous definition, cheat based on fact that every
  56        icalbody line looks like a contentline.  And we don't need to
  57        parse values. */
  58 contentline_list
  59     : contentline
  60     | contentline_list contentline
  61
  62     /* contentline = name *(";" param ) ":" value CRLF */
  63 contentline
  64     : ICAL_NAME {
  65           new_content_line (&vevents.last->contentlines);
  66           append (vevents.last->contentlines->last, $1, strlen ($1));
  67           vevents.last->contentlines->last->name = $1;
  68       } ICAL_COLON {
  69           append (vevents.last->contentlines->last, $3, strlen ($3));
  70       } ICAL_VALUE {
  71           append (vevents.last->contentlines->last, $5, strlen ($5));
  72           vevents.last->contentlines->last->value = $5;
  73       } ICAL_CRLF {
  74           append (vevents.last->contentlines->last, $7, strlen ($7));
  75           if (vevents.last->contentlines->cr_before_lf == CR_UNSET) {
  76               vevents.last->contentlines->cr_before_lf =
  77                   $7[0] == '\r'  ?  CR_BEFORE_LF  :  LF_ONLY;
  78           }
  79           /* END:VEVENT doesn't have a param_list so we don't need
  80              to check for it below. */
  81           if (vevents.last->contentlines->last->name  &&
  82               vevents.last->contentlines->last->value  &&
  83               ! strcasecmp (vevents.last->contentlines->last->name, "END")  &&
  84               ! strcasecmp (vevents.last->contentlines->last->value,
  85                             "VEVENT")) {
  86               new_vevent (&vevents);
  87           }
  88       }
  89     | ICAL_NAME {
  90           new_content_line (&vevents.last->contentlines);
  91           append (vevents.last->contentlines->last, $1, strlen ($1));
  92           vevents.last->contentlines->last->name = $1;
  93       } param_list ICAL_COLON {
  94           append (vevents.last->contentlines->last, $4, strlen ($4));
  95       } ICAL_VALUE {
  96           append (vevents.last->contentlines->last, $6, strlen ($6));
  97           vevents.last->contentlines->last->value = $6;
  98       } ICAL_CRLF {
  99           append (vevents.last->contentlines->last, $8, strlen ($8));
 100           if (vevents.last->contentlines->cr_before_lf == CR_UNSET) {
 101               vevents.last->contentlines->cr_before_lf =
 102                   $8[0] == '\r'  ?  CR_BEFORE_LF  :  LF_ONLY;
 103           }
 104       }
 105
 106 param_list
 107     : ICAL_SEMICOLON {
 108           append (vevents.last->contentlines->last, $1, strlen ($1));
 109       } param
 110     | param_list ICAL_SEMICOLON {
 111           append (vevents.last->contentlines->last, $2, strlen ($2));
 112       } param
 113
 114     /* param = param-name "=" param-value *("," param-value) */
 115 param
 116     : ICAL_PARAM_NAME {
 117           append (vevents.last->contentlines->last, $1, strlen ($1));
 118           add_param_name (vevents.last->contentlines->last, $1);
 119       } ICAL_EQUAL {
 120           append (vevents.last->contentlines->last, $3, strlen ($3));
 121       } param_value_list
 122
 123 param_value_list
 124     : ICAL_PARAM_VALUE {
 125           append (vevents.last->contentlines->last, $1, strlen ($1));
 126           add_param_value (vevents.last->contentlines->last, $1);
 127       }
 128     | param_value_list ICAL_COMMA {
 129           append (vevents.last->contentlines->last, $2, strlen ($2));
 130       } ICAL_PARAM_VALUE {
 131           append (vevents.last->contentlines->last, $4, strlen ($4));
 132           add_param_value (vevents.last->contentlines->last, $4);
 133       }
 134
 135 %%
 136
 137 /*
 138  * Remove the contentline node (by setting its name to NULL).
 139  */
 140 void
 141 remove_contentline (contentline *node) {
 142     free (node->name);
 143     node->name = NULL;
 144 }
 145
 146 contentline *
 147 add_contentline (contentline *node, const char *name) {
 148     contentline *new_node;
 149
 150     NEW0(new_node);
 151     new_node->name  = mh_xstrdup (name);
 152     new_node->next = node->next;
 153     node->next = new_node;
 154
 155     return new_node;
 156 }
 157
 158 /*
 159  * Remove the value from a value_list.
 160  */
 161 void
 162 remove_value (value_list *node) {
 163     free (node->value);
 164     node->value = NULL;
 165 }
 166
 167 /*
 168  * Find the contentline with the specified name, and optionally,
 169  * the specified value and/or parameter name.
 170  */
 171 contentline *
 172 find_contentline (contentline *contentlines, const char *name,
 173                   const char *val) {
 174     contentline *node;
 175
 176     for (node = contentlines; node; node = node->next) {
 177         /* node->name will be NULL if the line was "deleted". */
 178         if (node->name  &&  ! strcasecmp (name, node->name)) {
 179             if (!val || !node->value || !strcasecmp(val, node->value))
 180                 return node;
 181         }
 182     }
 183
 184     return NULL;
 185 }
 186
 187 static char *
 188 append (contentline *cline, const char *src, const size_t src_len) {
 189     if (src_len > 0) {
 190         const size_t len = cline->input_line_len + src_len;
 191
 192         while (len >= cline->input_line_size) {
 193             cline->input_line_size = cline->input_line_size == 0
 194                 ?  NMH_BUFSIZ
 195                 :  2 * cline->input_line_size;
 196             cline->input_line =
 197                 mh_xrealloc (cline->input_line, cline->input_line_size);
 198         }
 199
 200         memcpy (cline->input_line + cline->input_line_len, src, src_len);
 201         cline->input_line[len] = '\0';
 202         cline->input_line_len = len;
 203     }
 204
 205     return cline->input_line;
 206 }
 207
 208 static void
 209 new_content_line (contentline **cline) {
 210     contentline *new_node;
 211
 212     NEW0(new_node);
 213     if (*cline) {
 214         /* Append the new node to the end of the list. */
 215         (*cline)->last->next = new_node;
 216     } else {
 217         /* First line:  save the root node in *cline. */
 218         *cline = new_node;
 219     }
 220
 221     /* Only maintain the pointer to the last node in the root node. */
 222     (*cline)->last = new_node;
 223 }
 224
 225 static void
 226 new_vevent (vevent *event) {
 227     vevent *new_node, *node;
 228
 229     NEW0(new_node);
 230
 231     /* Append the new node to the end of the list. */
 232     for (node = event; node->next; node = node->next) { continue; }
 233     event->last =  node->next = new_node;
 234 }
 235
 236 void
 237 add_param_name (contentline *cline, char *name) {
 238     param_list *new_node;
 239     param_list *p;
 240
 241     NEW0(new_node);
 242     new_node->param_name = name;
 243
 244     if (cline->params) {
 245         for (p = cline->params; p->next; p = p->next) { continue; }
 246         /* The loop terminated at, not after, the last node. */
 247         p->next = new_node;
 248     } else {
 249         cline->params = new_node;
 250     }
 251 }
 252
 253 /*
 254  * Add a value to the last parameter seen.
 255  */
 256 void
 257 add_param_value (contentline *cline, char *value) {
 258     value_list *new_node;
 259     param_list *p;
 260     value_list *v;
 261
 262     NEW0(new_node);
 263     new_node->value = value;
 264
 265     if (cline->params) {
 266         for (p = cline->params; p->next; p = p->next) { continue; }
 267         /* The loop terminated at, not after, the last param_list node. */
 268
 269         if (p->values) {
 270             for (v = p->values; v->next; v = v->next) { continue; }
 271             /* The loop terminated at, not after, the last value_list node. */
 272             v->next = new_node;
 273         } else {
 274             p->values = new_node;
 275         }
 276     } else {
 277         /* Never should get here because a param value is always
 278            preceded by a param name. */
 279         free (new_node);
 280     }
 281 }
 282
 283 void
 284 free_contentlines (contentline *root) {
 285     contentline *i, *next;
 286
 287     for (i = root; i; i = next) {
 288         free (i->name);
 289         if (i->params) {
 290             free_param_names (i->params);
 291         }
 292         free (i->value);
 293         free (i->input_line);
 294         charstring_free (i->unexpected);
 295         next = i->next;
 296         free (i);
 297     }
 298 }
 299
 300 static void
 301 free_param_names (param_list *p) {
 302     param_list *next;
 303
 304     for ( ; p; p = next) {
 305         free (p->param_name);
 306         free_param_values (p->values);
 307         next = p->next;
 308         free (p);
 309     }
 310 }
 311
 312 static void
 313 free_param_values (value_list *v) {
 314     value_list *next;
 315
 316     for ( ; v; v = next) {
 317         free (v->value);
 318         next = v->next;
 319         free (v);
 320     }
 321 }
 322
 323 static int
 324 icalerror (const char *error) {
 325     contentline *c;
 326     charstring_t context = NULL;
 327
 328     /* Find last chunk of unexpected text. */
 329     for (c = vevents.last->contentlines; c; c = c->next) {
 330         if (c->unexpected) {
 331             context = c->unexpected;
 332         }
 333     }
 334
 335     if (! strcmp ("syntax error, unexpected $end, expecting ICAL_NAME",
 336                   error)) {
 337         /* Empty input: produce no output. */
 338     } else {
 339         if (context) {
 340             inform ("%s after \"%s\"", error, charstring_buffer (context));
 341         } else {
 342             inform ("%s", error);
 343         }
 344         parser_status = -1;
 345         return -1;
 346     }
 347
 348     return 0;  /* The return value isn't used anyway. */
 349 }
 350
 351 /*
 352  * In case YYDEBUG is disabled above; mhical refers to icaldebug.
 353  */
 354 #if ! defined YYDEBUG  ||  ! YYDEBUG
 355 int icaldebug;
 356 #endif /* ! YYDEBUG */