1 /* $NetBSD: cond.c,v 1.366 2024/07/06 21:21:09 rillig Exp $ */ 2 3 /* 4 * Copyright (c) 1988, 1989, 1990 The Regents of the University of California. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to Berkeley by 8 * Adam de Boor. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 */ 34 35 /* 36 * Copyright (c) 1988, 1989 by Adam de Boor 37 * Copyright (c) 1989 by Berkeley Softworks 38 * All rights reserved. 39 * 40 * This code is derived from software contributed to Berkeley by 41 * Adam de Boor. 42 * 43 * Redistribution and use in source and binary forms, with or without 44 * modification, are permitted provided that the following conditions 45 * are met: 46 * 1. Redistributions of source code must retain the above copyright 47 * notice, this list of conditions and the following disclaimer. 48 * 2. Redistributions in binary form must reproduce the above copyright 49 * notice, this list of conditions and the following disclaimer in the 50 * documentation and/or other materials provided with the distribution. 51 * 3. All advertising materials mentioning features or use of this software 52 * must display the following acknowledgement: 53 * This product includes software developed by the University of 54 * California, Berkeley and its contributors. 55 * 4. Neither the name of the University nor the names of its contributors 56 * may be used to endorse or promote products derived from this software 57 * without specific prior written permission. 58 * 59 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 60 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 61 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 62 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 63 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 64 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 65 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 66 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 67 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 68 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 69 * SUCH DAMAGE. 70 */ 71 72 /* 73 * Handling of conditionals in a makefile. 74 * 75 * Interface: 76 * Cond_EvalLine Evaluate the conditional directive, such as 77 * '.if <cond>', '.elifnmake <cond>', '.else', '.endif'. 78 * 79 * Cond_EvalCondition 80 * Evaluate the conditional, which is either the argument 81 * of one of the .if directives or the condition in a 82 * ':?then:else' variable modifier. 83 * 84 * Cond_EndFile At the end of reading a makefile, ensure that the 85 * conditional directives are well-balanced. 86 */ 87 88 #include <errno.h> 89 90 #include "make.h" 91 #include "dir.h" 92 93 /* "@(#)cond.c 8.2 (Berkeley) 1/2/94" */ 94 MAKE_RCSID("$NetBSD: cond.c,v 1.366 2024/07/06 21:21:09 rillig Exp $"); 95 96 /* 97 * Conditional expressions conform to this grammar: 98 * Or -> And ('||' And)* 99 * And -> Term ('&&' Term)* 100 * Term -> Function '(' Argument ')' 101 * Term -> Leaf Operator Leaf 102 * Term -> Leaf 103 * Term -> '(' Or ')' 104 * Term -> '!' Term 105 * Leaf -> "string" 106 * Leaf -> Number 107 * Leaf -> VariableExpression 108 * Leaf -> BareWord 109 * Operator -> '==' | '!=' | '>' | '<' | '>=' | '<=' 110 * 111 * BareWord is an unquoted string literal, its evaluation depends on the kind 112 * of '.if' directive. 113 * 114 * The tokens are scanned by CondParser_Token, which returns: 115 * TOK_AND for '&&' 116 * TOK_OR for '||' 117 * TOK_NOT for '!' 118 * TOK_LPAREN for '(' 119 * TOK_RPAREN for ')' 120 * 121 * Other terminal symbols are evaluated using either the default function or 122 * the function given in the terminal, they return either TOK_TRUE, TOK_FALSE 123 * or TOK_ERROR. 124 */ 125 typedef enum Token { 126 TOK_FALSE, TOK_TRUE, TOK_AND, TOK_OR, TOK_NOT, 127 TOK_LPAREN, TOK_RPAREN, TOK_EOF, TOK_NONE, TOK_ERROR 128 } Token; 129 130 typedef enum ComparisonOp { 131 LT, LE, GT, GE, EQ, NE 132 } ComparisonOp; 133 134 typedef struct CondParser { 135 136 /* 137 * The plain '.if ${VAR}' evaluates to true if the value of the 138 * expression has length > 0 and is not numerically zero. The other 139 * '.if' variants delegate to evalBare instead, for example '.ifdef 140 * ${VAR}' is equivalent to '.if defined(${VAR})', checking whether 141 * the variable named by the expression '${VAR}' is defined. 142 */ 143 bool plain; 144 145 /* The function to apply on unquoted bare words. */ 146 bool (*evalBare)(const char *); 147 bool negateEvalBare; 148 149 /* 150 * Whether the left-hand side of a comparison may be an unquoted 151 * string. This is allowed for expressions of the form 152 * ${condition:?:}, see ApplyModifier_IfElse. Such a condition is 153 * expanded before it is evaluated, due to ease of implementation. 154 * This means that at the point where the condition is evaluated, 155 * make cannot know anymore whether the left-hand side had originally 156 * been an expression or a plain word. 157 * 158 * In conditional directives like '.if', the left-hand side must 159 * either be an expression, a quoted string or a number. 160 */ 161 bool leftUnquotedOK; 162 163 const char *p; /* The remaining condition to parse */ 164 Token curr; /* Single push-back token used in parsing */ 165 166 /* 167 * Whether an error message has already been printed for this 168 * condition. 169 */ 170 bool printedError; 171 } CondParser; 172 173 static CondResult CondParser_Or(CondParser *, bool); 174 175 unsigned int cond_depth = 0; /* current .if nesting level */ 176 177 /* Names for ComparisonOp. */ 178 static const char opname[][3] = { "<", "<=", ">", ">=", "==", "!=" }; 179 180 MAKE_INLINE bool 181 skip_string(const char **pp, const char *str) 182 { 183 size_t len = strlen(str); 184 bool ok = strncmp(*pp, str, len) == 0; 185 if (ok) 186 *pp += len; 187 return ok; 188 } 189 190 static Token 191 ToToken(bool cond) 192 { 193 return cond ? TOK_TRUE : TOK_FALSE; 194 } 195 196 static void 197 CondParser_SkipWhitespace(CondParser *par) 198 { 199 cpp_skip_whitespace(&par->p); 200 } 201 202 /* 203 * Parse a single word, taking into account balanced parentheses as well as 204 * embedded expressions. Used for the argument of a built-in function as 205 * well as for bare words, which are then passed to the default function. 206 */ 207 static char * 208 ParseWord(const char **pp, bool doEval) 209 { 210 const char *p = *pp; 211 Buffer word; 212 int depth; 213 214 Buf_Init(&word); 215 216 depth = 0; 217 for (;;) { 218 char ch = *p; 219 if (ch == '\0' || ch == ' ' || ch == '\t') 220 break; 221 if ((ch == '&' || ch == '|') && depth == 0) 222 break; 223 if (ch == '$') { 224 VarEvalMode emode = doEval 225 ? VARE_EVAL_DEFINED 226 : VARE_PARSE; 227 /* 228 * TODO: make Var_Parse complain about undefined 229 * variables. 230 */ 231 FStr nestedVal = Var_Parse(&p, SCOPE_CMDLINE, emode); 232 /* TODO: handle errors */ 233 Buf_AddStr(&word, nestedVal.str); 234 FStr_Done(&nestedVal); 235 continue; 236 } 237 if (ch == '(') 238 depth++; 239 else if (ch == ')' && --depth < 0) 240 break; 241 Buf_AddByte(&word, ch); 242 p++; 243 } 244 245 cpp_skip_hspace(&p); 246 *pp = p; 247 248 return Buf_DoneData(&word); 249 } 250 251 /* Parse the function argument, including the surrounding parentheses. */ 252 static char * 253 ParseFuncArg(CondParser *par, const char **pp, bool doEval, const char *func) 254 { 255 const char *p = *pp; 256 char *res; 257 258 p++; /* skip the '(' */ 259 cpp_skip_hspace(&p); 260 res = ParseWord(&p, doEval); 261 cpp_skip_hspace(&p); 262 263 if (*p++ != ')') { 264 int len = 0; 265 while (ch_isalpha(func[len])) 266 len++; 267 268 Parse_Error(PARSE_FATAL, 269 "Missing closing parenthesis for %.*s()", len, func); 270 par->printedError = true; 271 free(res); 272 return NULL; 273 } 274 275 *pp = p; 276 return res; 277 } 278 279 /* See if the given variable is defined. */ 280 static bool 281 FuncDefined(const char *var) 282 { 283 return Var_Exists(SCOPE_CMDLINE, var); 284 } 285 286 /* See if a target matching targetPattern is requested to be made. */ 287 static bool 288 FuncMake(const char *targetPattern) 289 { 290 StringListNode *ln; 291 bool warned = false; 292 293 for (ln = opts.create.first; ln != NULL; ln = ln->next) { 294 StrMatchResult res = Str_Match(ln->datum, targetPattern); 295 if (res.error != NULL && !warned) { 296 warned = true; 297 Parse_Error(PARSE_WARNING, 298 "%s in pattern argument '%s' to function 'make'", 299 res.error, targetPattern); 300 } 301 if (res.matched) 302 return true; 303 } 304 return false; 305 } 306 307 /* See if the given file exists. */ 308 static bool 309 FuncExists(const char *file) 310 { 311 bool result; 312 char *path; 313 314 path = Dir_FindFile(file, &dirSearchPath); 315 DEBUG2(COND, "exists(%s) result is \"%s\"\n", 316 file, path != NULL ? path : ""); 317 result = path != NULL; 318 free(path); 319 return result; 320 } 321 322 /* See if the given node exists and is an actual target. */ 323 static bool 324 FuncTarget(const char *node) 325 { 326 GNode *gn = Targ_FindNode(node); 327 return gn != NULL && GNode_IsTarget(gn); 328 } 329 330 /* 331 * See if the given node exists and is an actual target with commands 332 * associated with it. 333 */ 334 static bool 335 FuncCommands(const char *node) 336 { 337 GNode *gn = Targ_FindNode(node); 338 return gn != NULL && GNode_IsTarget(gn) && 339 !Lst_IsEmpty(&gn->commands); 340 } 341 342 /* 343 * Convert the string to a floating point number. Accepted formats are 344 * base-10 integer, base-16 integer and finite floating point numbers. 345 */ 346 static bool 347 TryParseNumber(const char *str, double *out_value) 348 { 349 char *end; 350 unsigned long ul_val; 351 double dbl_val; 352 353 if (str[0] == '\0') { /* XXX: why is an empty string a number? */ 354 *out_value = 0.0; 355 return true; 356 } 357 358 errno = 0; 359 ul_val = strtoul(str, &end, str[1] == 'x' ? 16 : 10); 360 if (*end == '\0' && errno != ERANGE) { 361 *out_value = str[0] == '-' ? -(double)-ul_val : (double)ul_val; 362 return true; 363 } 364 365 if (*end != '\0' && *end != '.' && *end != 'e' && *end != 'E') 366 return false; /* skip the expensive strtod call */ 367 dbl_val = strtod(str, &end); 368 if (*end != '\0') 369 return false; 370 371 *out_value = dbl_val; 372 return true; 373 } 374 375 static bool 376 is_separator(char ch) 377 { 378 return ch == '\0' || ch_isspace(ch) || ch == '!' || ch == '=' || 379 ch == '>' || ch == '<' || ch == ')' /* but not '(' */; 380 } 381 382 /* 383 * In a quoted or unquoted string literal or a number, parse an 384 * expression and add its value to the buffer. 385 * 386 * Return whether to continue parsing the leaf. 387 * 388 * Example: .if x${CENTER}y == "${PREFIX}${SUFFIX}" || 0x${HEX} 389 */ 390 static bool 391 CondParser_StringExpr(CondParser *par, const char *start, 392 bool doEval, bool quoted, 393 Buffer *buf, FStr *inout_str) 394 { 395 VarEvalMode emode; 396 const char *p; 397 bool atStart; /* true means an expression outside quotes */ 398 399 emode = doEval && quoted ? VARE_EVAL 400 : doEval ? VARE_EVAL_DEFINED 401 : VARE_PARSE; 402 403 p = par->p; 404 atStart = p == start; 405 *inout_str = Var_Parse(&p, SCOPE_CMDLINE, emode); 406 /* TODO: handle errors */ 407 if (inout_str->str == var_Error) { 408 FStr_Done(inout_str); 409 *inout_str = FStr_InitRefer(NULL); 410 return false; 411 } 412 par->p = p; 413 414 if (atStart && is_separator(par->p[0])) 415 return false; 416 417 Buf_AddStr(buf, inout_str->str); 418 FStr_Done(inout_str); 419 *inout_str = FStr_InitRefer(NULL); /* not finished yet */ 420 return true; 421 } 422 423 /* 424 * Parse a string from an expression or an optionally quoted string, 425 * on the left-hand and right-hand sides of comparisons. 426 * 427 * Return the string without any enclosing quotes, or NULL on error. 428 * Sets out_quoted if the leaf was a quoted string literal. 429 */ 430 static FStr 431 CondParser_Leaf(CondParser *par, bool doEval, bool unquotedOK, 432 bool *out_quoted) 433 { 434 Buffer buf; 435 FStr str; 436 bool quoted; 437 const char *start; 438 439 Buf_Init(&buf); 440 str = FStr_InitRefer(NULL); 441 *out_quoted = quoted = par->p[0] == '"'; 442 start = par->p; 443 if (quoted) 444 par->p++; 445 446 while (par->p[0] != '\0' && str.str == NULL) { 447 switch (par->p[0]) { 448 case '\\': 449 par->p++; 450 if (par->p[0] != '\0') { 451 Buf_AddByte(&buf, par->p[0]); 452 par->p++; 453 } 454 continue; 455 case '"': 456 par->p++; 457 if (quoted) 458 goto return_buf; /* skip the closing quote */ 459 Buf_AddByte(&buf, '"'); 460 continue; 461 case ')': /* see is_separator */ 462 case '!': 463 case '=': 464 case '>': 465 case '<': 466 case ' ': 467 case '\t': 468 if (!quoted) 469 goto return_buf; 470 Buf_AddByte(&buf, par->p[0]); 471 par->p++; 472 continue; 473 case '$': 474 if (!CondParser_StringExpr(par, 475 start, doEval, quoted, &buf, &str)) 476 goto return_str; 477 continue; 478 default: 479 if (!unquotedOK && !quoted && *start != '$' && 480 !ch_isdigit(*start)) { 481 str = FStr_InitRefer(NULL); 482 goto return_str; 483 } 484 Buf_AddByte(&buf, par->p[0]); 485 par->p++; 486 continue; 487 } 488 } 489 return_buf: 490 str = FStr_InitOwn(buf.data); 491 buf.data = NULL; 492 return_str: 493 Buf_Done(&buf); 494 return str; 495 } 496 497 /* 498 * Evaluate a "comparison without operator", such as in ".if ${VAR}" or 499 * ".if 0". 500 */ 501 static bool 502 EvalTruthy(CondParser *par, const char *value, bool quoted) 503 { 504 double num; 505 506 if (quoted) 507 return value[0] != '\0'; 508 if (TryParseNumber(value, &num)) 509 return num != 0.0; 510 if (par->plain) 511 return value[0] != '\0'; 512 return par->evalBare(value) != par->negateEvalBare; 513 } 514 515 /* Evaluate a numerical comparison, such as in ".if ${VAR} >= 9". */ 516 static bool 517 EvalCompareNum(double lhs, ComparisonOp op, double rhs) 518 { 519 DEBUG3(COND, "Comparing %f %s %f\n", lhs, opname[op], rhs); 520 521 switch (op) { 522 case LT: 523 return lhs < rhs; 524 case LE: 525 return lhs <= rhs; 526 case GT: 527 return lhs > rhs; 528 case GE: 529 return lhs >= rhs; 530 case EQ: 531 return lhs == rhs; 532 default: 533 return lhs != rhs; 534 } 535 } 536 537 static Token 538 EvalCompareStr(CondParser *par, const char *lhs, 539 ComparisonOp op, const char *rhs) 540 { 541 if (op != EQ && op != NE) { 542 Parse_Error(PARSE_FATAL, 543 "Comparison with '%s' requires both operands " 544 "'%s' and '%s' to be numeric", 545 opname[op], lhs, rhs); 546 par->printedError = true; 547 return TOK_ERROR; 548 } 549 550 DEBUG3(COND, "Comparing \"%s\" %s \"%s\"\n", lhs, opname[op], rhs); 551 return ToToken((op == EQ) == (strcmp(lhs, rhs) == 0)); 552 } 553 554 /* Evaluate a comparison, such as "${VAR} == 12345". */ 555 static Token 556 EvalCompare(CondParser *par, const char *lhs, bool lhsQuoted, 557 ComparisonOp op, const char *rhs, bool rhsQuoted) 558 { 559 double left, right; 560 561 if (!rhsQuoted && !lhsQuoted) 562 if (TryParseNumber(lhs, &left) && TryParseNumber(rhs, &right)) 563 return ToToken(EvalCompareNum(left, op, right)); 564 565 return EvalCompareStr(par, lhs, op, rhs); 566 } 567 568 static bool 569 CondParser_ComparisonOp(CondParser *par, ComparisonOp *out_op) 570 { 571 const char *p = par->p; 572 573 if (p[0] == '<' && p[1] == '=') 574 return par->p += 2, *out_op = LE, true; 575 if (p[0] == '<') 576 return par->p += 1, *out_op = LT, true; 577 if (p[0] == '>' && p[1] == '=') 578 return par->p += 2, *out_op = GE, true; 579 if (p[0] == '>') 580 return par->p += 1, *out_op = GT, true; 581 if (p[0] == '=' && p[1] == '=') 582 return par->p += 2, *out_op = EQ, true; 583 if (p[0] == '!' && p[1] == '=') 584 return par->p += 2, *out_op = NE, true; 585 return false; 586 } 587 588 /* 589 * Parse a comparison condition such as: 590 * 591 * 0 592 * ${VAR:Mpattern} 593 * ${VAR} == value 594 * ${VAR:U0} < 12345 595 */ 596 static Token 597 CondParser_Comparison(CondParser *par, bool doEval) 598 { 599 Token t = TOK_ERROR; 600 FStr lhs, rhs; 601 ComparisonOp op; 602 bool lhsQuoted, rhsQuoted; 603 604 lhs = CondParser_Leaf(par, doEval, par->leftUnquotedOK, &lhsQuoted); 605 if (lhs.str == NULL) 606 goto done_lhs; 607 608 CondParser_SkipWhitespace(par); 609 610 if (!CondParser_ComparisonOp(par, &op)) { 611 t = ToToken(doEval && EvalTruthy(par, lhs.str, lhsQuoted)); 612 goto done_lhs; 613 } 614 615 CondParser_SkipWhitespace(par); 616 617 if (par->p[0] == '\0') { 618 Parse_Error(PARSE_FATAL, 619 "Missing right-hand side of operator '%s'", opname[op]); 620 par->printedError = true; 621 goto done_lhs; 622 } 623 624 rhs = CondParser_Leaf(par, doEval, true, &rhsQuoted); 625 t = rhs.str == NULL ? TOK_ERROR 626 : !doEval ? TOK_FALSE 627 : EvalCompare(par, lhs.str, lhsQuoted, op, rhs.str, rhsQuoted); 628 FStr_Done(&rhs); 629 630 done_lhs: 631 FStr_Done(&lhs); 632 return t; 633 } 634 635 /* 636 * The argument to empty() is a variable name, optionally followed by 637 * variable modifiers. 638 */ 639 static bool 640 CondParser_FuncCallEmpty(CondParser *par, bool doEval, Token *out_token) 641 { 642 const char *p = par->p; 643 Token tok; 644 FStr val; 645 646 if (!skip_string(&p, "empty")) 647 return false; 648 649 cpp_skip_whitespace(&p); 650 if (*p != '(') 651 return false; 652 653 p--; /* Make p[1] point to the '('. */ 654 val = Var_Parse(&p, SCOPE_CMDLINE, doEval ? VARE_EVAL : VARE_PARSE); 655 /* TODO: handle errors */ 656 657 if (val.str == var_Error) 658 tok = TOK_ERROR; 659 else { 660 cpp_skip_whitespace(&val.str); 661 tok = ToToken(doEval && val.str[0] == '\0'); 662 } 663 664 FStr_Done(&val); 665 *out_token = tok; 666 par->p = p; 667 return true; 668 } 669 670 /* Parse a function call expression, such as 'exists(${file})'. */ 671 static bool 672 CondParser_FuncCall(CondParser *par, bool doEval, Token *out_token) 673 { 674 char *arg; 675 const char *p = par->p; 676 bool (*fn)(const char *); 677 const char *fn_name = p; 678 679 if (skip_string(&p, "defined")) 680 fn = FuncDefined; 681 else if (skip_string(&p, "make")) 682 fn = FuncMake; 683 else if (skip_string(&p, "exists")) 684 fn = FuncExists; 685 else if (skip_string(&p, "target")) 686 fn = FuncTarget; 687 else if (skip_string(&p, "commands")) 688 fn = FuncCommands; 689 else 690 return false; 691 692 cpp_skip_whitespace(&p); 693 if (*p != '(') 694 return false; 695 696 arg = ParseFuncArg(par, &p, doEval, fn_name); 697 *out_token = ToToken(doEval && 698 arg != NULL && arg[0] != '\0' && fn(arg)); 699 free(arg); 700 701 par->p = p; 702 return true; 703 } 704 705 /* 706 * Parse a comparison that neither starts with '"' nor '$', such as the 707 * unusual 'bare == right' or '3 == ${VAR}', or a simple leaf without 708 * operator, which is a number, an expression or a string literal. 709 * 710 * TODO: Can this be merged into CondParser_Comparison? 711 */ 712 static Token 713 CondParser_ComparisonOrLeaf(CondParser *par, bool doEval) 714 { 715 Token t; 716 char *arg; 717 const char *p; 718 719 p = par->p; 720 if (ch_isdigit(p[0]) || p[0] == '-' || p[0] == '+') 721 return CondParser_Comparison(par, doEval); 722 723 /* 724 * Most likely we have a bare word to apply the default function to. 725 * However, ".if a == b" gets here when the "a" is unquoted and 726 * doesn't start with a '$'. This surprises people. 727 * If what follows the function argument is a '=' or '!' then the 728 * syntax would be invalid if we did "defined(a)" - so instead treat 729 * as an expression. 730 */ 731 /* 732 * XXX: In edge cases, an expression may be evaluated twice, 733 * see cond-token-plain.mk, keyword 'twice'. 734 */ 735 arg = ParseWord(&p, doEval); 736 assert(arg[0] != '\0'); 737 738 if (*p == '=' || *p == '!' || *p == '<' || *p == '>') { 739 free(arg); 740 return CondParser_Comparison(par, doEval); 741 } 742 par->p = p; 743 744 /* 745 * Evaluate the argument using the default function. 746 * This path always treats .if as .ifdef. To get here, the character 747 * after .if must have been taken literally, so the argument cannot 748 * be empty - even if it contained an expression. 749 */ 750 t = ToToken(doEval && par->evalBare(arg) != par->negateEvalBare); 751 free(arg); 752 return t; 753 } 754 755 /* Return the next token or comparison result from the parser. */ 756 static Token 757 CondParser_Token(CondParser *par, bool doEval) 758 { 759 Token t; 760 761 t = par->curr; 762 if (t != TOK_NONE) { 763 par->curr = TOK_NONE; 764 return t; 765 } 766 767 cpp_skip_hspace(&par->p); 768 769 switch (par->p[0]) { 770 771 case '(': 772 par->p++; 773 return TOK_LPAREN; 774 775 case ')': 776 par->p++; 777 return TOK_RPAREN; 778 779 case '|': 780 par->p++; 781 if (par->p[0] == '|') 782 par->p++; 783 else { 784 Parse_Error(PARSE_FATAL, "Unknown operator '|'"); 785 par->printedError = true; 786 return TOK_ERROR; 787 } 788 return TOK_OR; 789 790 case '&': 791 par->p++; 792 if (par->p[0] == '&') 793 par->p++; 794 else { 795 Parse_Error(PARSE_FATAL, "Unknown operator '&'"); 796 par->printedError = true; 797 return TOK_ERROR; 798 } 799 return TOK_AND; 800 801 case '!': 802 par->p++; 803 return TOK_NOT; 804 805 case '#': /* XXX: see unit-tests/cond-token-plain.mk */ 806 case '\n': /* XXX: why should this end the condition? */ 807 /* Probably obsolete now, from 1993-03-21. */ 808 case '\0': 809 return TOK_EOF; 810 811 case '"': 812 case '$': 813 return CondParser_Comparison(par, doEval); 814 815 default: 816 if (CondParser_FuncCallEmpty(par, doEval, &t)) 817 return t; 818 if (CondParser_FuncCall(par, doEval, &t)) 819 return t; 820 return CondParser_ComparisonOrLeaf(par, doEval); 821 } 822 } 823 824 /* Skip the next token if it equals t. */ 825 static bool 826 CondParser_Skip(CondParser *par, Token t) 827 { 828 Token actual; 829 830 actual = CondParser_Token(par, false); 831 if (actual == t) 832 return true; 833 834 assert(par->curr == TOK_NONE); 835 assert(actual != TOK_NONE); 836 par->curr = actual; 837 return false; 838 } 839 840 /* 841 * Term -> '(' Or ')' 842 * Term -> '!' Term 843 * Term -> Leaf Operator Leaf 844 * Term -> Leaf 845 */ 846 static CondResult 847 CondParser_Term(CondParser *par, bool doEval) 848 { 849 CondResult res; 850 Token t; 851 bool neg = false; 852 853 while ((t = CondParser_Token(par, doEval)) == TOK_NOT) 854 neg = !neg; 855 856 if (t == TOK_TRUE || t == TOK_FALSE) 857 return neg == (t == TOK_FALSE) ? CR_TRUE : CR_FALSE; 858 859 if (t == TOK_LPAREN) { 860 res = CondParser_Or(par, doEval); 861 if (res == CR_ERROR) 862 return CR_ERROR; 863 if (CondParser_Token(par, doEval) != TOK_RPAREN) 864 return CR_ERROR; 865 return neg == (res == CR_FALSE) ? CR_TRUE : CR_FALSE; 866 } 867 868 return CR_ERROR; 869 } 870 871 /* 872 * And -> Term ('&&' Term)* 873 */ 874 static CondResult 875 CondParser_And(CondParser *par, bool doEval) 876 { 877 CondResult res, rhs; 878 879 res = CR_TRUE; 880 do { 881 if ((rhs = CondParser_Term(par, doEval)) == CR_ERROR) 882 return CR_ERROR; 883 if (rhs == CR_FALSE) { 884 res = CR_FALSE; 885 doEval = false; 886 } 887 } while (CondParser_Skip(par, TOK_AND)); 888 889 return res; 890 } 891 892 /* 893 * Or -> And ('||' And)* 894 */ 895 static CondResult 896 CondParser_Or(CondParser *par, bool doEval) 897 { 898 CondResult res, rhs; 899 900 res = CR_FALSE; 901 do { 902 if ((rhs = CondParser_And(par, doEval)) == CR_ERROR) 903 return CR_ERROR; 904 if (rhs == CR_TRUE) { 905 res = CR_TRUE; 906 doEval = false; 907 } 908 } while (CondParser_Skip(par, TOK_OR)); 909 910 return res; 911 } 912 913 /* 914 * Evaluate the condition, including any side effects from the 915 * expressions in the condition. The condition consists of &&, ||, !, 916 * function(arg), comparisons and parenthetical groupings thereof. 917 */ 918 static CondResult 919 CondEvalExpression(const char *cond, bool plain, 920 bool (*evalBare)(const char *), bool negate, 921 bool eprint, bool leftUnquotedOK) 922 { 923 CondParser par; 924 CondResult rval; 925 926 cpp_skip_hspace(&cond); 927 928 par.plain = plain; 929 par.evalBare = evalBare; 930 par.negateEvalBare = negate; 931 par.leftUnquotedOK = leftUnquotedOK; 932 par.p = cond; 933 par.curr = TOK_NONE; 934 par.printedError = false; 935 936 DEBUG1(COND, "CondParser_Eval: %s\n", par.p); 937 rval = CondParser_Or(&par, true); 938 if (par.curr != TOK_EOF) 939 rval = CR_ERROR; 940 941 if (rval == CR_ERROR && eprint && !par.printedError) 942 Parse_Error(PARSE_FATAL, "Malformed conditional (%s)", cond); 943 944 return rval; 945 } 946 947 /* 948 * Evaluate a condition in a :? modifier, such as 949 * ${"${VAR}" == value:?yes:no}. 950 */ 951 CondResult 952 Cond_EvalCondition(const char *cond) 953 { 954 return CondEvalExpression(cond, true, 955 FuncDefined, false, false, true); 956 } 957 958 static bool 959 IsEndif(const char *p) 960 { 961 return p[0] == 'e' && p[1] == 'n' && p[2] == 'd' && 962 p[3] == 'i' && p[4] == 'f' && !ch_isalpha(p[5]); 963 } 964 965 static bool 966 DetermineKindOfConditional(const char **pp, bool *out_plain, 967 bool (**out_evalBare)(const char *), 968 bool *out_negate) 969 { 970 const char *p = *pp + 2; 971 972 *out_plain = false; 973 *out_evalBare = FuncDefined; 974 *out_negate = skip_string(&p, "n"); 975 976 if (skip_string(&p, "def")) { /* .ifdef and .ifndef */ 977 } else if (skip_string(&p, "make")) /* .ifmake and .ifnmake */ 978 *out_evalBare = FuncMake; 979 else if (!*out_negate) /* plain .if */ 980 *out_plain = true; 981 else 982 goto unknown_directive; 983 if (ch_isalpha(*p)) 984 goto unknown_directive; 985 986 *pp = p; 987 return true; 988 989 unknown_directive: 990 return false; 991 } 992 993 /* 994 * Evaluate the conditional directive in the line, which is one of: 995 * 996 * .if <cond> 997 * .ifmake <cond> 998 * .ifnmake <cond> 999 * .ifdef <cond> 1000 * .ifndef <cond> 1001 * .elif <cond> 1002 * .elifmake <cond> 1003 * .elifnmake <cond> 1004 * .elifdef <cond> 1005 * .elifndef <cond> 1006 * .else 1007 * .endif 1008 * 1009 * In these directives, <cond> consists of &&, ||, !, function(arg), 1010 * comparisons, expressions, bare words, numbers and strings, and 1011 * parenthetical groupings thereof. 1012 * 1013 * Results: 1014 * CR_TRUE to continue parsing the lines that follow the 1015 * conditional (when <cond> evaluates to true) 1016 * CR_FALSE to skip the lines after the conditional 1017 * (when <cond> evaluates to false, or when a previous 1018 * branch was already taken) 1019 * CR_ERROR if the conditional was not valid, either because of 1020 * a syntax error or because some variable was undefined 1021 * or because the condition could not be evaluated 1022 */ 1023 CondResult 1024 Cond_EvalLine(const char *line) 1025 { 1026 typedef enum IfState { 1027 1028 /* None of the previous <cond> evaluated to true. */ 1029 IFS_INITIAL = 0, 1030 1031 /* 1032 * The previous <cond> evaluated to true. The lines following 1033 * this condition are interpreted. 1034 */ 1035 IFS_ACTIVE = 1 << 0, 1036 1037 /* The previous directive was an '.else'. */ 1038 IFS_SEEN_ELSE = 1 << 1, 1039 1040 /* One of the previous <cond> evaluated to true. */ 1041 IFS_WAS_ACTIVE = 1 << 2 1042 1043 } IfState; 1044 1045 static enum IfState *cond_states = NULL; 1046 static unsigned int cond_states_cap = 128; 1047 1048 bool plain; 1049 bool (*evalBare)(const char *); 1050 bool negate; 1051 bool isElif; 1052 CondResult res; 1053 IfState state; 1054 const char *p = line; 1055 1056 if (cond_states == NULL) { 1057 cond_states = bmake_malloc( 1058 cond_states_cap * sizeof *cond_states); 1059 cond_states[0] = IFS_ACTIVE; 1060 } 1061 1062 p++; /* skip the leading '.' */ 1063 cpp_skip_hspace(&p); 1064 1065 if (IsEndif(p)) { 1066 if (p[5] != '\0') { 1067 Parse_Error(PARSE_FATAL, 1068 "The .endif directive does not take arguments"); 1069 } 1070 1071 if (cond_depth == CurFile_CondMinDepth()) { 1072 Parse_Error(PARSE_FATAL, "if-less endif"); 1073 return CR_TRUE; 1074 } 1075 1076 /* Return state for previous conditional */ 1077 cond_depth--; 1078 Parse_GuardEndif(); 1079 return cond_states[cond_depth] & IFS_ACTIVE 1080 ? CR_TRUE : CR_FALSE; 1081 } 1082 1083 /* Parse the name of the directive, such as 'if', 'elif', 'endif'. */ 1084 if (p[0] == 'e') { 1085 if (p[1] != 'l') 1086 return CR_ERROR; 1087 1088 /* Quite likely this is 'else' or 'elif' */ 1089 p += 2; 1090 if (strncmp(p, "se", 2) == 0 && !ch_isalpha(p[2])) { 1091 if (p[2] != '\0') 1092 Parse_Error(PARSE_FATAL, 1093 "The .else directive " 1094 "does not take arguments"); 1095 1096 if (cond_depth == CurFile_CondMinDepth()) { 1097 Parse_Error(PARSE_FATAL, "if-less else"); 1098 return CR_TRUE; 1099 } 1100 Parse_GuardElse(); 1101 1102 state = cond_states[cond_depth]; 1103 if (state == IFS_INITIAL) { 1104 state = IFS_ACTIVE | IFS_SEEN_ELSE; 1105 } else { 1106 if (state & IFS_SEEN_ELSE) 1107 Parse_Error(PARSE_WARNING, 1108 "extra else"); 1109 state = IFS_WAS_ACTIVE | IFS_SEEN_ELSE; 1110 } 1111 cond_states[cond_depth] = state; 1112 1113 return state & IFS_ACTIVE ? CR_TRUE : CR_FALSE; 1114 } 1115 /* Assume for now it is an elif */ 1116 isElif = true; 1117 } else 1118 isElif = false; 1119 1120 if (p[0] != 'i' || p[1] != 'f') 1121 return CR_ERROR; 1122 1123 if (!DetermineKindOfConditional(&p, &plain, &evalBare, &negate)) 1124 return CR_ERROR; 1125 1126 if (isElif) { 1127 if (cond_depth == CurFile_CondMinDepth()) { 1128 Parse_Error(PARSE_FATAL, "if-less elif"); 1129 return CR_TRUE; 1130 } 1131 Parse_GuardElse(); 1132 state = cond_states[cond_depth]; 1133 if (state & IFS_SEEN_ELSE) { 1134 Parse_Error(PARSE_WARNING, "extra elif"); 1135 cond_states[cond_depth] = 1136 IFS_WAS_ACTIVE | IFS_SEEN_ELSE; 1137 return CR_FALSE; 1138 } 1139 if (state != IFS_INITIAL) { 1140 cond_states[cond_depth] = IFS_WAS_ACTIVE; 1141 return CR_FALSE; 1142 } 1143 } else { 1144 /* Normal .if */ 1145 if (cond_depth + 1 >= cond_states_cap) { 1146 /* 1147 * This is rare, but not impossible. 1148 * In meta mode, dirdeps.mk (only runs at level 0) 1149 * can need more than the default. 1150 */ 1151 cond_states_cap += 32; 1152 cond_states = bmake_realloc(cond_states, 1153 cond_states_cap * sizeof *cond_states); 1154 } 1155 state = cond_states[cond_depth]; 1156 cond_depth++; 1157 if (!(state & IFS_ACTIVE)) { 1158 cond_states[cond_depth] = IFS_WAS_ACTIVE; 1159 return CR_FALSE; 1160 } 1161 } 1162 1163 res = CondEvalExpression(p, plain, evalBare, negate, true, false); 1164 if (res == CR_ERROR) { 1165 /* Syntax error, error message already output. */ 1166 /* Skip everything to the matching '.endif'. */ 1167 /* An extra '.else' is not detected in this case. */ 1168 cond_states[cond_depth] = IFS_WAS_ACTIVE; 1169 return CR_FALSE; 1170 } 1171 1172 cond_states[cond_depth] = res == CR_TRUE ? IFS_ACTIVE : IFS_INITIAL; 1173 return res; 1174 } 1175 1176 static bool 1177 ParseVarnameGuard(const char **pp, const char **varname) 1178 { 1179 const char *p = *pp; 1180 1181 if (ch_isalpha(*p) || *p == '_') { 1182 while (ch_isalnum(*p) || *p == '_') 1183 p++; 1184 *varname = *pp; 1185 *pp = p; 1186 return true; 1187 } 1188 return false; 1189 } 1190 1191 /* Extracts the multiple-inclusion guard from a conditional, if any. */ 1192 Guard * 1193 Cond_ExtractGuard(const char *line) 1194 { 1195 const char *p, *varname; 1196 Substring dir; 1197 Guard *guard; 1198 1199 p = line + 1; /* skip the '.' */ 1200 cpp_skip_hspace(&p); 1201 1202 dir.start = p; 1203 while (ch_isalpha(*p)) 1204 p++; 1205 dir.end = p; 1206 cpp_skip_hspace(&p); 1207 1208 if (Substring_Equals(dir, "if")) { 1209 if (skip_string(&p, "!defined(")) { 1210 if (ParseVarnameGuard(&p, &varname) 1211 && strcmp(p, ")") == 0) 1212 goto found_variable; 1213 } else if (skip_string(&p, "!target(")) { 1214 const char *arg_p = p; 1215 free(ParseWord(&p, false)); 1216 if (strcmp(p, ")") == 0) { 1217 guard = bmake_malloc(sizeof(*guard)); 1218 guard->kind = GK_TARGET; 1219 guard->name = ParseWord(&arg_p, true); 1220 return guard; 1221 } 1222 } 1223 } else if (Substring_Equals(dir, "ifndef")) { 1224 if (ParseVarnameGuard(&p, &varname) && *p == '\0') 1225 goto found_variable; 1226 } 1227 return NULL; 1228 1229 found_variable: 1230 guard = bmake_malloc(sizeof(*guard)); 1231 guard->kind = GK_VARIABLE; 1232 guard->name = bmake_strsedup(varname, p); 1233 return guard; 1234 } 1235 1236 void 1237 Cond_EndFile(void) 1238 { 1239 unsigned int open_conds = cond_depth - CurFile_CondMinDepth(); 1240 1241 if (open_conds != 0) { 1242 Parse_Error(PARSE_FATAL, "%u open conditional%s", 1243 open_conds, open_conds == 1 ? "" : "s"); 1244 cond_depth = CurFile_CondMinDepth(); 1245 } 1246 } 1247