cmd-cnd.c

   1 /*@ S-nail - a mail user agent derived from Berkeley Mail.
   2  *@ Commands: conditional constructs.
   3  *
   4  * Copyright (c) 2014 - 2017 Steffen (Daode) Nurpmeso <steffen@sdaoden.eu>.
   5  *
   6  * Permission to use, copy, modify, and/or distribute this software for any
   7  * purpose with or without fee is hereby granted, provided that the above
   8  * copyright notice and this permission notice appear in all copies.
   9  *
  10  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  11  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  12  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  13  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  14  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  15  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  16  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  17  */
  18 #undef n_FILE
  19 #define n_FILE cmd_cnd
  20
  21 #ifndef HAVE_AMALGAMATION
  22 # include "nail.h"
  23 #endif
  24
  25 #define a_CCND_IF_ISSKIP() \
  26    (n_go_data->gdc_ifcond != NULL &&\
  27       (((struct a_ccnd_if_node*)n_go_data->gdc_ifcond)->cin_noop ||\
  28        !((struct a_ccnd_if_node*)n_go_data->gdc_ifcond)->cin_go))
  29
  30 struct a_ccnd_if_node{
  31    struct a_ccnd_if_node *cin_outer;
  32    bool_t cin_error;    /* Bad expression, skip entire if..endif */
  33    bool_t cin_noop;     /* Outer stack !cin_go, entirely no-op */
  34    bool_t cin_go;       /* Green light */
  35    bool_t cin_else;     /* In `else' clause */
  36    ui8_t cin__dummy[4];
  37 };
  38
  39 struct a_ccnd_if_ctx{
  40    char const * const *cic_argv_base;
  41    char const * const *cic_argv_max;   /* BUT: .cic_argv MUST be terminated! */
  42    char const * const *cic_argv;
  43 };
  44
  45 /* */
  46 static void a_ccnd_oif_error(struct a_ccnd_if_ctx const *cicp,
  47                char const *msg_or_null, char const *nearby_or_null);
  48
  49 /* noop and (1) don't work for real, only syntax-check and
  50  * (2) non-error return is ignored */
  51 static si8_t a_ccnd_oif_test(struct a_ccnd_if_ctx *cicp, bool_t noop);
  52 static si8_t a_ccnd_oif_group(struct a_ccnd_if_ctx *cicp, size_t level,
  53                bool_t noop);
  54
  55 /* Shared `if' / `elif' implementation */
  56 static int a_ccnd_if(void *v, bool_t iselif);
  57
  58 static void
  59 a_ccnd_oif_error(struct a_ccnd_if_ctx const *cicp, char const *msg_or_null,
  60       char const *nearby_or_null){
  61    struct str s;
  62    NYD2_ENTER;
  63
  64    if(msg_or_null == NULL)
  65       msg_or_null = _("invalid expression syntax");
  66
  67    if(nearby_or_null != NULL)
  68       n_err(_("`if' conditional: %s -- near: %s\n"),
  69          msg_or_null, nearby_or_null);
  70    else
  71       n_err(_("`if' conditional: %s\n"), msg_or_null);
  72
  73    if((n_psonce & n_PSO_INTERACTIVE) || (n_poption & n_PO_D_V)){
  74       str_concat_cpa(&s, cicp->cic_argv_base,
  75          (*cicp->cic_argv_base != NULL ? " " : n_empty));
  76       n_err(_("   Expression: %s\n"), s.s);
  77
  78       str_concat_cpa(&s, cicp->cic_argv,
  79          (*cicp->cic_argv != NULL ? " " : n_empty));
  80       n_err(_("   Stopped at: %s\n"), s.s);
  81    }
  82    NYD2_LEAVE;
  83 }
  84
  85 static si8_t
  86 a_ccnd_oif_test(struct a_ccnd_if_ctx *cicp, bool_t noop){
  87    char const *emsg, * const *argv, *cp, *lhv, *op, *rhv;
  88    size_t argc;
  89    char c;
  90    si8_t rv;
  91    NYD2_ENTER;
  92
  93    rv = -1;
  94    emsg = NULL;
  95    argv = cicp->cic_argv;
  96    argc = PTR2SIZE(cicp->cic_argv_max - cicp->cic_argv);
  97    cp = argv[0];
  98
  99    if(*cp != '$'){
 100       if(argc > 1)
 101          goto jesyn;
 102    }else if(cp[1] == '\0')
 103       goto jesyn;
 104    else if(argc > 3){
 105 #ifdef HAVE_REGEX
 106 jesyn_ntr:
 107 #endif
 108       if(0){
 109 jesyn:
 110          if(emsg != NULL)
 111             emsg = V_(emsg);
 112       }
 113       a_ccnd_oif_error(cicp, emsg, cp);
 114       goto jleave;
 115    }
 116
 117    switch(*cp){
 118    default:
 119       switch(boolify(cp, UIZ_MAX, -1)){
 120       case 0: rv = FAL0; break;
 121       case 1: rv = TRU1; break;
 122       default:
 123          emsg = N_("Expected a boolean");
 124          goto jesyn;
 125       }
 126       break;
 127    case 'R': case 'r':
 128       rv = !(n_psonce & n_PSO_SENDMODE);
 129       break;
 130    case 'S': case 's':
 131       rv = ((n_psonce & n_PSO_SENDMODE) != 0);
 132       break;
 133    case 'T': case 't':
 134       if(!asccasecmp(cp, "true")) /* Beware! */
 135          rv = TRU1;
 136       else
 137          rv = ((n_psonce & n_PSO_INTERACTIVE) != 0);
 138       break;
 139    case '$':{
 140       enum{
 141          a_NONE,
 142          a_ICASE = 1u<<0
 143       } flags = a_NONE;
 144
 145       /* Look up the value in question, we need it anyway */
 146       if(*++cp == '{'){
 147          size_t i = strlen(cp);
 148
 149          if(i > 0 && cp[i - 1] == '}')
 150             cp = savestrbuf(++cp, i -= 2);
 151          else
 152             goto jesyn;
 153       }
 154       if(noop)
 155          lhv = NULL;
 156       else
 157          lhv = n_var_vlook(cp, TRU1);
 158
 159       /* Single argument, "implicit boolean" form? */
 160       if(argc == 1){
 161          rv = (lhv != NULL);
 162          break;
 163       }
 164       op = argv[1];
 165
 166       /* Three argument comparison form required, check syntax */
 167       emsg = N_("unrecognized condition");
 168       if(argc == 2 || (c = op[0]) == '\0')
 169          goto jesyn;
 170
 171       /* May be modifier */
 172       if(c == '@'){
 173          for(;;){
 174             c = *++op;
 175             if(c == 'i')
 176                flags |= a_ICASE;
 177             else
 178                break;
 179          }
 180          if(flags == a_NONE)
 181             flags = a_ICASE;
 182       }
 183
 184       if(op[1] == '\0'){
 185          if(c != '<' && c != '>')
 186             goto jesyn;
 187       }else if(c != '-' && op[2] != '\0')
 188          goto jesyn;
 189       else if(c == '<' || c == '>'){
 190          if(op[1] != '=')
 191             goto jesyn;
 192       }else if(c == '=' || c == '!'){
 193          if(op[1] != '=' && op[1] != '%' && op[1] != '@'
 194 #ifdef HAVE_REGEX
 195                && op[1] != '~'
 196 #endif
 197          )
 198             goto jesyn;
 199       }else if(c == '-'){
 200          if(op[1] == '\0' || op[2] == '\0' || op[3] != '\0')
 201             goto jesyn;
 202          if(op[1] == 'e'){
 203             if(op[2] != 'q')
 204                goto jesyn;
 205          }else if(op[1] == 'g' || op[1] == 'l'){
 206             if(op[2] != 'e' && op[2] != 't')
 207                goto jesyn;
 208          }else if(op[1] == 'n'){
 209             if(op[2] != 'e')
 210                goto jesyn;
 211          }else
 212             goto jesyn;
 213       }else
 214          goto jesyn;
 215
 216       /* The right hand side may also be a variable, more syntax checking */
 217       emsg = N_("invalid right hand side");
 218       if((rhv = argv[2]) == NULL /* Can't happen */)
 219          goto jesyn;
 220       if(*rhv == '$'){
 221          if(*++rhv == '\0')
 222             goto jesyn;
 223          else if(*rhv == '{'){
 224             size_t i = strlen(rhv);
 225
 226             if(i > 0 && rhv[i - 1] == '}')
 227                rhv = savestrbuf(++rhv, i -= 2);
 228             else{
 229                cp = --rhv;
 230                goto jesyn;
 231             }
 232          }
 233          if(noop)
 234             rhv = NULL;
 235          else
 236             rhv = n_var_vlook(cp = rhv, TRU1);
 237       }
 238
 239       /* A null value is treated as the empty string */
 240       emsg = NULL;
 241       if(lhv == NULL)
 242          lhv = n_UNCONST(n_empty);
 243       if(rhv == NULL)
 244          rhv = n_UNCONST(n_empty);
 245
 246 #ifdef HAVE_REGEX
 247       if(op[1] == '~'){
 248          regex_t re;
 249          int s;
 250
 251          if((s = regcomp(&re, rhv, REG_EXTENDED | REG_NOSUB |
 252                (flags & a_ICASE ? REG_ICASE : 0))) != 0){
 253             emsg = savecat(_("invalid regular expression: "),
 254                   n_regex_err_to_doc(&re, s));
 255             goto jesyn_ntr;
 256          }
 257          if(!noop)
 258             rv = (regexec(&re, lhv, 0,NULL, 0) == REG_NOMATCH) ^ (c == '=');
 259          regfree(&re);
 260       }else
 261 #endif
 262             if(noop)
 263          break;
 264       else if(op[1] == '%' || op[1] == '@'){
 265          if(op[1] == '@')
 266             n_OBSOLETE("`if'++: \"=@\" and \"!@\" became \"=%\" and \"!%\"");
 267          rv = ((flags & a_ICASE ? asccasestr(lhv, rhv) : strstr(lhv, rhv)
 268                ) == NULL) ^ (c == '=');
 269       }else if(c == '-'){
 270          si64_t lhvi, rhvi;
 271
 272          if(*lhv == '\0')
 273             lhv = n_0;
 274          if(*rhv == '\0')
 275             rhv = n_0;
 276          if((n_idec_si64_cp(&lhvi, lhv, 0, NULL
 277                   ) & (n_IDEC_STATE_EMASK | n_IDEC_STATE_CONSUMED)
 278                ) != n_IDEC_STATE_CONSUMED || (n_idec_si64_cp(&rhvi, rhv, 0, NULL
 279                   ) & (n_IDEC_STATE_EMASK | n_IDEC_STATE_CONSUMED)
 280                ) != n_IDEC_STATE_CONSUMED){
 281             emsg = N_("integer expression expected");
 282             goto jesyn;
 283          }
 284
 285          lhvi -= rhvi;
 286          switch(op[1]){
 287          default:
 288          case 'e': rv = (lhvi == 0); break;
 289          case 'n': rv = (lhvi != 0); break;
 290          case 'l': rv = (op[2] == 't') ? lhvi < 0 : lhvi <= 0; break;
 291          case 'g': rv = (op[2] == 't') ? lhvi > 0 : lhvi >= 0; break;
 292          }
 293          break;
 294       }else{
 295          si32_t scmp;
 296
 297          scmp = (flags & a_ICASE) ? asccasecmp(lhv, rhv) : strcmp(lhv, rhv);
 298          switch(c){
 299          default:
 300          case '=': rv = (scmp == 0); break;
 301          case '!': rv = (scmp != 0); break;
 302          case '<': rv = (op[1] == '\0') ? scmp < 0 : scmp <= 0; break;
 303          case '>': rv = (op[1] == '\0') ? scmp > 0 : scmp >= 0; break;
 304          }
 305       }
 306    }  break;
 307    }
 308
 309    if(noop && rv < 0)
 310       rv = TRU1;
 311 jleave:
 312    NYD2_LEAVE;
 313    return rv;
 314 }
 315
 316 static si8_t
 317 a_ccnd_oif_group(struct a_ccnd_if_ctx *cicp, size_t level, bool_t noop){
 318    char const *emsg, *arg0, * const *argv, * const *argv_max_save;
 319    size_t i;
 320    char unary, c;
 321    enum{
 322       a_FIRST = 1<<0,
 323       a_END_OK = 1<<1,
 324       a_NEED_LIST = 1<<2,
 325
 326       a_CANNOT_UNARY = a_NEED_LIST,
 327       a_CANNOT_OBRACK = a_NEED_LIST,
 328       a_CANNOT_CBRACK = a_FIRST,
 329       a_CANNOT_LIST = a_FIRST,
 330       a_CANNOT_COND = a_NEED_LIST
 331    } state;
 332    si8_t rv, xrv;
 333    NYD2_ENTER;
 334
 335    rv = -1;
 336    state = a_FIRST;
 337    unary = '\0';
 338    emsg = NULL;
 339
 340    for(;;){
 341       arg0 = *(argv = cicp->cic_argv);
 342       if(arg0 == NULL){
 343          if(!(state & a_END_OK)){
 344             emsg = N_("missing expression (premature end)");
 345             goto jesyn;
 346          }
 347          if(noop && rv < 0)
 348             rv = TRU1;
 349          break; /* goto jleave; */
 350       }
 351
 352       switch((c = *arg0)){
 353       case '!':
 354          if(arg0[1] != '\0')
 355             goto jneed_cond;
 356
 357          if(state & a_CANNOT_UNARY){
 358             emsg = N_("cannot use a unary operator here");
 359             goto jesyn;
 360          }
 361
 362          unary = (unary != '\0') ? '\0' : c;
 363          state &= ~(a_FIRST | a_END_OK);
 364          cicp->cic_argv = ++argv;
 365          continue;
 366
 367       case '[':
 368       case ']':
 369          if(arg0[1] != '\0')
 370             goto jneed_cond;
 371
 372          if(c == '['){
 373             if(state & a_CANNOT_OBRACK){
 374                emsg = N_("cannot open a group here");
 375                goto jesyn;
 376             }
 377
 378             cicp->cic_argv = ++argv;
 379             if((xrv = a_ccnd_oif_group(cicp, level + 1, noop)) < 0){
 380                rv = xrv;
 381                goto jleave;
 382             }else if(!noop)
 383                rv = (unary != '\0') ? !xrv : xrv;
 384
 385             unary = '\0';
 386             state &= ~(a_FIRST | a_END_OK);
 387             state |= (level == 0 ? a_END_OK : 0) | a_NEED_LIST;
 388             continue;
 389          }else{
 390             if(state & a_CANNOT_CBRACK){
 391                emsg = N_("cannot use closing bracket here");
 392                goto jesyn;
 393             }
 394
 395             if(level == 0){
 396                emsg = N_("no open groups to be closed here");
 397                goto jesyn;
 398             }
 399
 400             cicp->cic_argv = ++argv;
 401             if(noop && rv < 0)
 402                rv = TRU1;
 403             goto jleave;/* break;break; */
 404          }
 405
 406       case '|':
 407       case '&':
 408          if(c != arg0[1] || arg0[2] != '\0')
 409             goto jneed_cond;
 410
 411          if(state & a_CANNOT_LIST){
 412             emsg = N_("cannot use a AND-OR list here");
 413             goto jesyn;
 414          }
 415
 416          noop = ((c == '&') ^ (rv == TRU1));
 417          state &= ~(a_FIRST | a_END_OK | a_NEED_LIST);
 418          cicp->cic_argv = ++argv;
 419          continue;
 420
 421       default:
 422 jneed_cond:
 423          if(state & a_CANNOT_COND){
 424             emsg = N_("cannot use a `if' condition here");
 425             goto jesyn;
 426          }
 427
 428          for(i = 0;; ++i){
 429             if((arg0 = argv[i]) == NULL)
 430                break;
 431             c = *arg0;
 432             if(c == '!' && arg0[1] == '\0')
 433                break;
 434             if((c == '[' || c == ']') && arg0[1] == '\0')
 435                break;
 436             if((c == '&' || c == '|') && c == arg0[1] && arg0[2] == '\0')
 437                break;
 438          }
 439          if(i == 0){
 440             emsg = N_("empty conditional group");
 441             goto jesyn;
 442          }
 443
 444          argv_max_save = cicp->cic_argv_max;
 445          cicp->cic_argv_max = argv + i;
 446          if((xrv = a_ccnd_oif_test(cicp, noop)) < 0){
 447             rv = xrv;
 448             goto jleave;
 449          }else if(!noop)
 450             rv = (unary != '\0') ? !xrv : xrv;
 451          cicp->cic_argv_max = argv_max_save;
 452
 453          cicp->cic_argv = (argv += i);
 454          unary = '\0';
 455          state &= ~a_FIRST;
 456          state |= a_END_OK | a_NEED_LIST;
 457          break;
 458       }
 459    }
 460
 461 jleave:
 462    NYD2_LEAVE;
 463    return rv;
 464 jesyn:
 465    if(emsg == NULL)
 466       emsg = N_("invalid grouping");
 467    a_ccnd_oif_error(cicp, V_(emsg), arg0);
 468    rv = -1;
 469    goto jleave;
 470 }
 471
 472 static int
 473 a_ccnd_if(void *v, bool_t iselif){
 474    struct a_ccnd_if_ctx cic;
 475    char const * const *argv;
 476    size_t argc;
 477    si8_t xrv, rv;
 478    struct a_ccnd_if_node *cinp;
 479    NYD_ENTER;
 480
 481    if(!iselif){
 482       cinp = smalloc(sizeof *cinp);
 483       cinp->cin_outer = n_go_data->gdc_ifcond;
 484    }else{
 485       cinp = n_go_data->gdc_ifcond;
 486       assert(cinp != NULL);
 487    }
 488    cinp->cin_error = FAL0;
 489    cinp->cin_noop = a_CCND_IF_ISSKIP();
 490    cinp->cin_go = TRU1;
 491    cinp->cin_else = FAL0;
 492    if(!iselif)
 493       n_go_data->gdc_ifcond = cinp;
 494
 495    if(cinp->cin_noop){
 496       rv = 0;
 497       goto jleave;
 498    }
 499
 500    /* For heaven's sake, support comments _today_ TODO wyshlist.. */
 501    for(argc = 0, argv = v; argv[argc] != NULL; ++argc)
 502       if(argv[argc][0] == '#'){
 503          char const **nav = salloc(sizeof(char*) * (argc + 1));
 504          size_t i;
 505
 506          for(i = 0; i < argc; ++i)
 507             nav[i] = argv[i];
 508          nav[i] = NULL;
 509          argv = nav;
 510          break;
 511       }
 512    cic.cic_argv_base = cic.cic_argv = argv;
 513    cic.cic_argv_max = &argv[argc];
 514    xrv = a_ccnd_oif_group(&cic, 0, FAL0);
 515
 516    if(xrv >= 0){
 517       cinp->cin_go = (bool_t)xrv;
 518       rv = 0;
 519    }else{
 520       cinp->cin_error = cinp->cin_noop = TRU1;
 521       rv = 1;
 522    }
 523 jleave:
 524    NYD_LEAVE;
 525    return rv;
 526 }
 527
 528 FL int
 529 c_if(void *v){
 530    int rv;
 531    NYD_ENTER;
 532
 533    rv = a_ccnd_if(v, FAL0);
 534    NYD_LEAVE;
 535    return rv;
 536 }
 537
 538 FL int
 539 c_elif(void *v){
 540    struct a_ccnd_if_node *cinp;
 541    int rv;
 542    NYD_ENTER;
 543
 544    if((cinp = n_go_data->gdc_ifcond) == NULL || cinp->cin_else){
 545       n_err(_("`elif' without a matching `if'\n"));
 546       rv = 1;
 547    }else if(!cinp->cin_error){
 548       cinp->cin_go = !cinp->cin_go; /* Cause right _IF_ISSKIP() result */
 549       rv = a_ccnd_if(v, TRU1);
 550    }else
 551       rv = 0;
 552    NYD_LEAVE;
 553    return rv;
 554 }
 555
 556 FL int
 557 c_else(void *v){
 558    int rv;
 559    struct a_ccnd_if_node *cinp;
 560    NYD_ENTER;
 561    n_UNUSED(v);
 562
 563    if((cinp = n_go_data->gdc_ifcond) == NULL || cinp->cin_else){
 564       n_err(_("`else' without a matching `if'\n"));
 565       rv = 1;
 566    }else{
 567       cinp->cin_else = TRU1;
 568       cinp->cin_go = !cinp->cin_go;
 569       rv = 0;
 570    }
 571    NYD_LEAVE;
 572    return rv;
 573 }
 574
 575 FL int
 576 c_endif(void *v){
 577    int rv;
 578    struct a_ccnd_if_node *cinp;
 579    NYD_ENTER;
 580    n_UNUSED(v);
 581
 582    if((cinp = n_go_data->gdc_ifcond) == NULL){
 583       n_err(_("`endif' without a matching `if'\n"));
 584       rv = 1;
 585    }else{
 586       n_go_data->gdc_ifcond = cinp->cin_outer;
 587       free(cinp);
 588       rv = 0;
 589    }
 590    NYD_LEAVE;
 591    return rv;
 592 }
 593
 594 FL bool_t
 595 n_cnd_if_isskip(void){
 596    bool_t rv;
 597    NYD2_ENTER;
 598
 599    rv = a_CCND_IF_ISSKIP();
 600    NYD2_LEAVE;
 601    return rv;
 602 }
 603
 604 FL void
 605 n_cnd_if_stack_del(struct n_go_data_ctx *gdcp){
 606    struct a_ccnd_if_node *vp, *cinp;
 607    NYD2_ENTER;
 608
 609    vp = gdcp->gdc_ifcond;
 610    gdcp->gdc_ifcond = NULL;
 611
 612    while((cinp = vp) != NULL){
 613       vp = cinp->cin_outer;
 614       free(cinp);
 615    }
 616    NYD2_LEAVE;
 617 }
 618
 619 /* s-it-mode */