git.ozlabs.org Git - ccan/blob - ccan/cdump/cdump.c

   1 /* MIT (BSD) license - see LICENSE file for details */
   2 #include "cdump.h"
   3 #include <ccan/tal/str/str.h>
   4 #include <assert.h>
   5
   6 struct token {
   7         const char *p;
   8         size_t len;
   9 };
  10
  11 static void add_token(struct token **toks, const char *p, size_t len)
  12 {
  13         size_t n = tal_count(*toks);
  14         tal_resize(toks, n+1);
  15         (*toks)[n].p = p;
  16         (*toks)[n].len = len;
  17 }
  18
  19 static size_t to_eol(const char *p)
  20 {
  21         size_t len = strcspn(p, "\n");
  22
  23         /* And any \ continuations. */
  24         while (p[len] && p[len-1] == '\\')
  25                 len += strcspn(p+len+1, "\n") + 1;
  26         return len;
  27 }
  28
  29 /* Simplified tokenizer: comments and preproc directives removed,
  30    identifiers are a token, others are single char tokens. */
  31 static struct token *tokenize(const void *ctx, const char *code)
  32 {
  33         unsigned int i, len, tok_start = -1;
  34         bool start_of_line = true;
  35         struct token *toks = tal_arr(ctx, struct token, 0);
  36
  37         for (i = 0; code[i]; i += len) {
  38                 if (code[i] == '#' && start_of_line) {
  39                         /* Preprocessor line. */
  40                         len = to_eol(code + i);
  41                 } else if (code[i] == '/' && code[i+1] == '/') {
  42                         /* One line comment. */
  43                         len = to_eol(code + i);
  44                         if (tok_start != -1U) {
  45                                 add_token(&toks, code+tok_start, i - tok_start);
  46                                 tok_start = -1U;
  47                         }
  48                 } else if (code[i] == '/' && code[i+1] == '*') {
  49                         /* Multi-line comment. */
  50                         const char *end = strstr(code+i+2, "*/");
  51                         len = (end + 2) - (code + i);
  52                         if (!end)
  53                                 len = strlen(code + i);
  54                         if (tok_start != -1U) {
  55                                 add_token(&toks, code+tok_start, i - tok_start);
  56                                 tok_start = -1U;
  57                         }
  58                 } else if (cisalnum(code[i]) || code[i] == '_') {
  59                         /* Identifier or part thereof */
  60                         if (tok_start == -1U)
  61                                 tok_start = i;
  62                         len = 1;
  63                 } else if (!cisspace(code[i])) {
  64                         /* Punctuation: treat as single char token. */
  65                         if (tok_start != -1U) {
  66                                 add_token(&toks, code+tok_start, i - tok_start);
  67                                 tok_start = -1U;
  68                         }
  69                         add_token(&toks, code+i, 1);
  70                         len = 1;
  71                 } else {
  72                         /* Whitespace. */
  73                         if (tok_start != -1U) {
  74                                 add_token(&toks, code+tok_start, i - tok_start);
  75                                 tok_start = -1U;
  76                         }
  77                         len = 1;
  78                 }
  79                 if (code[i] == '\n')
  80                         start_of_line = true;
  81                 else if (!cisspace(code[i]))
  82                         start_of_line = false;
  83         }
  84
  85         /* Add terminating NULL. */
  86         tal_resizez(&toks, tal_count(toks) + 1);
  87         return toks;
  88 }
  89
  90 struct parse_state {
  91         const char *code;
  92         const struct token *toks;
  93         struct cdump_definitions *defs;
  94         char *complaints;
  95 };
  96
  97 static const struct token *tok_peek(const struct token **toks)
  98 {
  99         /* Ignore removed tokens (eg. comments) */
 100         while (toks[0]->len == 0) {
 101                 if (!toks[0]->p)
 102                         return NULL;
 103                 (*toks)++;
 104         }
 105         return toks[0];
 106 }
 107
 108 static bool tok_is(const struct token **toks, const char *target)
 109 {
 110         const struct token *t = tok_peek(toks);
 111         return (t && t->len == strlen(target)
 112                 && memcmp(t->p, target, t->len) == 0);
 113 }
 114
 115 static const struct token *tok_take(const struct token **toks)
 116 {
 117         const struct token *t = tok_peek(toks);
 118         if (t)
 119                 (*toks)++;
 120
 121         return t;
 122 }
 123
 124 static const struct token *tok_take_if(const struct token **toks,
 125                                        const char *target)
 126 {
 127         if (tok_is(toks, target))
 128                 return tok_take(toks);
 129         return NULL;
 130 }
 131
 132 static const char *tok_take_ident(const tal_t *ctx, const struct token **toks)
 133 {
 134         const struct token *t = tok_peek(toks);
 135
 136         if (!t)
 137                 return NULL;
 138
 139         if (strspn(t->p, "_0123456789"
 140                    "abcdefghijklmnopqrstuvwxyz"
 141                    "ABCDEFGHIJKLMNOPQRSTUVWXYZ") < t->len)
 142                 return NULL;
 143
 144         t = tok_take(toks);
 145         return tal_strndup(ctx, t->p, t->len);
 146 }
 147
 148 static char *string_of_toks(const tal_t *ctx,
 149                             const struct token *first,
 150                             const struct token *until)
 151 {
 152         char *str, *p;
 153
 154         /* Careful to skip erased tokens (eg. comments) */
 155         str = p = tal_arr(ctx, char, until->p - first->p + 1);
 156         while (first != until) {
 157                 const struct token *next = first + 1;
 158
 159                 if (first->len) {
 160                         memcpy(p, first->p, first->len);
 161                         p += first->len;
 162                         /* Insert space if they weren't adjacent, unless last */
 163                         if (next != until) {
 164                                 if (first->p + first->len != next->p)
 165                                         *(p++) = ' ';
 166                         }
 167                 }
 168                 first = next;
 169         }
 170         *p = '\0';
 171
 172         return str;
 173 }
 174
 175 static char *tok_take_until(const tal_t *ctx,
 176                             const struct token **toks,
 177                             const char *delims)
 178 {
 179         const struct token *t, *start;
 180
 181         start = tok_peek(toks);
 182         while ((t = tok_peek(toks)) != NULL) {
 183                 /* If this contains a delimiter, copy up to prev token. */
 184                 if (strcspn(t->p, delims) < t->len)
 185                         return string_of_toks(ctx, start, t);
 186                 tok_take(toks);
 187         };
 188
 189         /* EOF without finding delimiter */
 190         return NULL;
 191 }
 192
 193 static bool type_defined(const struct cdump_type *t)
 194 {
 195         switch (t->kind) {
 196         case CDUMP_STRUCT:
 197         case CDUMP_UNION:
 198                 return (t->u.members != NULL);
 199         case CDUMP_ENUM:
 200                 return (t->u.enum_vals != NULL);
 201
 202         /* These shouldn't happen; we don't try to define them. */
 203         case CDUMP_UNKNOWN:
 204         case CDUMP_ARRAY:
 205         case CDUMP_POINTER:
 206                 break;
 207         }
 208         abort();
 209 }
 210
 211 /* May allocate a new type if not already found (steals @name) */
 212 static struct cdump_type *get_type(struct cdump_definitions *defs,
 213                                    enum cdump_type_kind kind,
 214                                    const char *name)
 215 {
 216         struct cdump_map *m;
 217         struct cdump_type *t;
 218
 219         switch (kind) {
 220         case CDUMP_STRUCT:
 221                 m = &defs->structs;
 222                 break;
 223         case CDUMP_UNION:
 224                 m = &defs->unions;
 225                 break;
 226         case CDUMP_ENUM:
 227                 m = &defs->enums;
 228                 break;
 229         case CDUMP_UNKNOWN:
 230         case CDUMP_ARRAY:
 231         case CDUMP_POINTER:
 232                 m = NULL;
 233         }
 234
 235         /* Do we already have it? */
 236         if (m) {
 237                 t = strmap_get(m, name);
 238                 if (t)
 239                         return t;
 240         }
 241
 242         t = tal(defs, struct cdump_type);
 243         t->kind = kind;
 244         t->name = name ? tal_steal(t, name) : NULL;
 245         /* These are actually the same, but be thorough */
 246         t->u.members = NULL;
 247         t->u.enum_vals = NULL;
 248         if (m)
 249                 strmap_add(m, t->name, t);
 250
 251         return t;
 252 }
 253
 254 static void complain(struct parse_state *ps, const char *complaint)
 255 {
 256         unsigned int linenum;
 257         const char *p = ps->code;
 258
 259         for (linenum = 1; p < ps->toks[0].p; linenum++) {
 260                 p = strchr(p+1, '\n');
 261                 if (!p)
 262                         break;
 263         }
 264
 265         tal_append_fmt(&ps->complaints,
 266                        "Line %u: '%.*s': %s\n",
 267                        linenum, (int)ps->toks[0].len,
 268                        ps->toks[0].p, complaint);
 269 }
 270
 271 static void tok_take_unknown_statement(struct parse_state *ps)
 272 {
 273         complain(ps, "Ignoring unknown statement until next semicolon");
 274         tal_free(tok_take_until(NULL, &ps->toks, ";"));
 275         tok_take_if(&ps->toks, ";");
 276 }
 277
 278 static bool tok_take_expr(struct parse_state *ps, const char *term)
 279 {
 280         while (!tok_is(&ps->toks, term)) {
 281                 if (tok_take_if(&ps->toks, "(")) {
 282                         if (!tok_take_expr(ps, ")"))
 283                                 return false;
 284                 } else if (tok_take_if(&ps->toks, "[")) {
 285                         if (!tok_take_expr(ps, "]"))
 286                                 return false;
 287                 } else if (!tok_take(&ps->toks))
 288                         return false;
 289         }
 290         return tok_take(&ps->toks);
 291 }
 292
 293 static char *tok_take_expr_str(const tal_t *ctx,
 294                                struct parse_state *ps,
 295                                const char *term)
 296 {
 297         const struct token *start = tok_peek(&ps->toks);
 298
 299         if (!tok_take_expr(ps, term))
 300                 return NULL;
 301
 302         return string_of_toks(ctx, start, ps->toks - 1);
 303 }
 304
 305 /* [ ... */
 306 static bool tok_take_array(struct parse_state *ps, struct cdump_type **type)
 307 {
 308         /* This will be some arbitrary expression! */
 309         struct cdump_type *arr = get_type(ps->defs, CDUMP_ARRAY, NULL);
 310
 311         arr->u.arr.size = tok_take_expr_str(arr, ps, "]");
 312         if (!arr->u.arr.size) {
 313                 complain(ps, "Could not find closing array size ]");
 314                 return false;
 315         }
 316
 317         arr->u.arr.type = *type;
 318         *type = arr;
 319
 320         return true;
 321 }
 322
 323 static struct cdump_type *ptr_of(struct parse_state *ps,
 324                                  const struct cdump_type *ptr_to)
 325 {
 326         struct cdump_type *ptr = get_type(ps->defs, CDUMP_POINTER, NULL);
 327         ptr->u.ptr = ptr_to;
 328         return ptr;
 329 }
 330
 331 static bool tok_take_type(struct parse_state *ps, struct cdump_type **type)
 332 {
 333         const char *name;
 334         const struct token *types;
 335         enum cdump_type_kind kind;
 336
 337         /* Ignoring weird typedefs, only these can be combined. */
 338         types = ps->toks;
 339         while (tok_take_if(&ps->toks, "int")
 340                || tok_take_if(&ps->toks, "long")
 341                || tok_take_if(&ps->toks, "short")
 342                || tok_take_if(&ps->toks, "double")
 343                || tok_take_if(&ps->toks, "float")
 344                || tok_take_if(&ps->toks, "char")
 345                || tok_take_if(&ps->toks, "signed")
 346                || tok_take_if(&ps->toks, "unsigned"));
 347
 348         /* Did we get some? */
 349         if (ps->toks != types) {
 350                 name = string_of_toks(NULL, types, tok_peek(&ps->toks));
 351                 kind = CDUMP_UNKNOWN;
 352         } else {
 353                 /* Try normal types (or simple typedefs, etc). */
 354                 if (tok_take_if(&ps->toks, "struct")) {
 355                         kind = CDUMP_STRUCT;
 356                 } else if (tok_take_if(&ps->toks, "union")) {
 357                         kind = CDUMP_UNION;
 358                 } else if (tok_take_if(&ps->toks, "enum")) {
 359                         kind = CDUMP_ENUM;
 360                 } else
 361                         kind = CDUMP_UNKNOWN;
 362
 363                 name = tok_take_ident(ps->defs, &ps->toks);
 364                 if (!name) {
 365                         complain(ps, "Invalid typename");
 366                         return false;
 367                 }
 368         }
 369
 370         *type = get_type(ps->defs, kind, name);
 371         return true;
 372 }
 373
 374 /* CDUMP */
 375 static bool tok_maybe_take_cdump_note(const tal_t *ctx,
 376                                       struct parse_state *ps, const char **note)
 377 {
 378         *note = NULL;
 379         if (tok_take_if(&ps->toks, "CDUMP")) {
 380                 if (!tok_take_if(&ps->toks, "(")) {
 381                         complain(ps, "Expected ( after CDUMP");
 382                         return false;
 383                 }
 384                 *note = tok_take_expr_str(ctx, ps, ")");
 385                 if (!*note) {
 386                         complain(ps, "Expected ) after CDUMP(");
 387                         return false;
 388                 }
 389         }
 390         return true;
 391 }
 392
 393 /* struct|union ... */
 394 static bool tok_take_conglom(struct parse_state *ps,
 395                              enum cdump_type_kind conglom_kind)
 396 {
 397         struct cdump_type *e;
 398         const char *name;
 399         size_t n;
 400
 401         assert(conglom_kind == CDUMP_STRUCT || conglom_kind == CDUMP_UNION);
 402
 403         name = tok_take_ident(ps->defs, &ps->toks);
 404         if (!name) {
 405                 complain(ps, "Invalid struct/union name");
 406                 return false;
 407         }
 408
 409         e = get_type(ps->defs, conglom_kind, name);
 410         if (type_defined(e)) {
 411                 complain(ps, "Type already defined");
 412                 return false;
 413         }
 414
 415         if (!tok_maybe_take_cdump_note(e, ps, &e->note))
 416                 return false;
 417
 418         if (!tok_take_if(&ps->toks, "{")) {
 419                 complain(ps, "Expected { for struct/union");
 420                 return false;
 421         }
 422
 423         e->u.members = tal_arr(e, struct cdump_member, n = 0);
 424         while (!tok_is(&ps->toks, "}")) {
 425                 struct cdump_type *basetype;
 426                 const struct token *quals;
 427                 unsigned int num_quals = 0;
 428
 429                 /* Anything can have these prepended. */
 430                 quals = ps->toks;
 431                 while (tok_take_if(&ps->toks, "const")
 432                        || tok_take_if(&ps->toks, "volatile"))
 433                         num_quals++;
 434
 435                 /* eg. "struct foo" or "varint_t" */
 436                 if (!tok_take_type(ps, &basetype)) {
 437                         complain(ps, "Expected typename inside struct/union");
 438                         return false;
 439                 }
 440
 441                 do {
 442                         struct cdump_member *m;
 443
 444                         tal_resize(&e->u.members, n+1);
 445                         m = &e->u.members[n++];
 446                         m->type = basetype;
 447                         if (num_quals) {
 448                                 m->qualifiers
 449                                         = string_of_toks(e, quals,
 450                                                          quals + num_quals);
 451                         } else
 452                                 m->qualifiers = NULL;
 453
 454                         /* May have multiple asterisks. */
 455                         while (tok_take_if(&ps->toks, "*"))
 456                                 m->type = ptr_of(ps, m->type);
 457
 458                         m->name = tok_take_ident(e, &ps->toks);
 459                         if (!m->name) {
 460                                 complain(ps, "Expected name for member");
 461                                 return false;
 462                         }
 463
 464                         /* May be an array. */
 465                         while (tok_take_if(&ps->toks, "[")) {
 466                                 if (!tok_take_array(ps, &m->type))
 467                                         return false;
 468                         }
 469
 470                         /* CDUMP() */
 471                         if (!tok_maybe_take_cdump_note(e->u.members,
 472                                                        ps, &m->note))
 473                                 return false;
 474                 } while (tok_take_if(&ps->toks, ","));
 475
 476                 if (!tok_take_if(&ps->toks, ";")) {
 477                         complain(ps, "Expected ; at end of member");
 478                         return false;
 479                 }
 480         }
 481
 482         if (tok_take_if(&ps->toks, "}") && tok_take_if(&ps->toks, ";"))
 483                 return true;
 484         complain(ps, "Expected }; at end of struct/union");
 485         return false;
 486 }
 487
 488 /* enum ... */
 489 static bool tok_take_enum(struct parse_state *ps)
 490 {
 491         size_t n = 0;
 492         struct cdump_type *e;
 493         const char *name;
 494
 495         name = tok_take_ident(ps->defs, &ps->toks);
 496         if (!name) {
 497                 complain(ps, "Expected enum name");
 498                 return false;
 499         }
 500
 501         e = get_type(ps->defs, CDUMP_ENUM, name);
 502
 503         /* Duplicate name? */
 504         if (type_defined(e)) {
 505                 complain(ps, "enum already defined");
 506                 return false;
 507         }
 508
 509         /* CDUMP() */
 510         if (!tok_maybe_take_cdump_note(e, ps, &e->note))
 511                 return false;
 512
 513         if (!tok_take_if(&ps->toks, "{")) {
 514                 complain(ps, "Expected { after enum name");
 515                 return false;
 516         }
 517
 518         e->u.enum_vals = tal_arr(e, struct cdump_enum_val, n);
 519         do {
 520                 struct cdump_enum_val *v;
 521
 522                 /* GCC extension: comma and end of enum */
 523                 if (tok_is(&ps->toks, "}"))
 524                         break;
 525
 526                 tal_resize(&e->u.enum_vals, n+1);
 527                 v = &e->u.enum_vals[n++];
 528
 529                 v->name = tok_take_ident(e, &ps->toks);
 530                 if (!v->name) {
 531                         complain(ps, "Expected enum value name");
 532                         return false;
 533                 }
 534
 535                 /* CDUMP() */
 536                 if (!tok_maybe_take_cdump_note(e->u.enum_vals, ps, &v->note))
 537                         return false;
 538
 539                 if (tok_take_if(&ps->toks, "=")) {
 540                         v->value = tok_take_until(e, &ps->toks, ",}");
 541                         if (!v->value) {
 542                                 complain(ps, "Expected , or } to end value");
 543                                 return false;
 544                         }
 545                 } else
 546                         v->value = NULL;
 547         } while (tok_take_if(&ps->toks, ","));
 548
 549         if (tok_take_if(&ps->toks, "}") && tok_take_if(&ps->toks, ";"))
 550                 return true;
 551
 552         complain(ps, "Expected }; at end of enum");
 553         return false;
 554 }
 555
 556 static bool gather_undefines(const char *name,
 557                              struct cdump_type *t,
 558                              struct cdump_map *undefs)
 559 {
 560         if (!type_defined(t))
 561                 strmap_add(undefs, name, t);
 562         return true;
 563 }
 564
 565 static bool remove_from_map(const char *name,
 566                             struct cdump_type *t,
 567                             struct cdump_map *map)
 568 {
 569         strmap_del(map, name, NULL);
 570         return true;
 571 }
 572
 573 static void remove_undefined(struct cdump_map *map)
 574 {
 575         struct cdump_map undefs;
 576
 577         /* We can't delete inside iterator, so gather all the undefs
 578          * then remove them. */
 579         strmap_init(&undefs);
 580
 581         strmap_iterate(map, gather_undefines, &undefs);
 582         strmap_iterate(&undefs, remove_from_map, map);
 583         strmap_clear(&undefs);
 584 }
 585
 586 static void destroy_definitions(struct cdump_definitions *defs)
 587 {
 588         strmap_clear(&defs->enums);
 589         strmap_clear(&defs->structs);
 590         strmap_clear(&defs->unions);
 591 }
 592
 593 /* Simple LL(1) parser, inspired by Tridge's genstruct.pl. */
 594 struct cdump_definitions *cdump_extract(const tal_t *ctx, const char *code,
 595                                         char **complaints)
 596 {
 597         struct parse_state ps;
 598         const struct token *toks;
 599
 600         ps.defs = tal(ctx, struct cdump_definitions);
 601         ps.complaints = tal_strdup(ctx, "");
 602         ps.code = code;
 603
 604         strmap_init(&ps.defs->enums);
 605         strmap_init(&ps.defs->structs);
 606         strmap_init(&ps.defs->unions);
 607         tal_add_destructor(ps.defs, destroy_definitions);
 608
 609         toks = ps.toks = tokenize(ps.defs, code);
 610         while (tok_peek(&ps.toks)) {
 611                 if (tok_take_if(&ps.toks, "struct")) {
 612                         if (!tok_take_conglom(&ps, CDUMP_STRUCT))
 613                                 goto fail;
 614                 } else if (tok_take_if(&ps.toks, "union")) {
 615                         if (!tok_take_conglom(&ps, CDUMP_UNION))
 616                                 goto fail;
 617                 } else if (tok_take_if(&ps.toks, "enum")) {
 618                         if (!tok_take_enum(&ps))
 619                                 goto fail;
 620                 } else
 621                         tok_take_unknown_statement(&ps);
 622         }
 623
 624         /* Now, remove any undefined types! */
 625         remove_undefined(&ps.defs->enums);
 626         remove_undefined(&ps.defs->structs);
 627         remove_undefined(&ps.defs->unions);
 628         tal_free(toks);
 629
 630 out:
 631         if (streq(ps.complaints, ""))
 632                 ps.complaints = tal_free(ps.complaints);
 633
 634         if (complaints)
 635                 *complaints = ps.complaints;
 636         else
 637                 tal_free(ps.complaints);
 638         return ps.defs;
 639
 640 fail:
 641         ps.defs = tal_free(ps.defs);
 642         goto out;
 643 }