1 /* $NetBSD: for.c,v 1.46 2009/01/17 13:29:37 dsl Exp $ */ 2 3 /* 4 * Copyright (c) 1992, The Regents of the University of California. 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. Neither the name of the University nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 */ 31 32 #ifndef MAKE_NATIVE 33 static char rcsid[] = "$NetBSD: for.c,v 1.46 2009/01/17 13:29:37 dsl Exp $"; 34 #else 35 #include <sys/cdefs.h> 36 #ifndef lint 37 #if 0 38 static char sccsid[] = "@(#)for.c 8.1 (Berkeley) 6/6/93"; 39 #else 40 __RCSID("$NetBSD: for.c,v 1.46 2009/01/17 13:29:37 dsl Exp $"); 41 #endif 42 #endif /* not lint */ 43 #endif 44 45 /*- 46 * for.c -- 47 * Functions to handle loops in a makefile. 48 * 49 * Interface: 50 * For_Eval Evaluate the loop in the passed line. 51 * For_Run Run accumulated loop 52 * 53 */ 54 55 #include <assert.h> 56 #include <ctype.h> 57 58 #include "make.h" 59 #include "hash.h" 60 #include "dir.h" 61 #include "buf.h" 62 #include "strlist.h" 63 64 #define FOR_SUB_ESCAPE_CHAR 1 65 #define FOR_SUB_ESCAPE_BRACE 2 66 #define FOR_SUB_ESCAPE_PAREN 4 67 68 /* 69 * For statements are of the form: 70 * 71 * .for <variable> in <varlist> 72 * ... 73 * .endfor 74 * 75 * The trick is to look for the matching end inside for for loop 76 * To do that, we count the current nesting level of the for loops. 77 * and the .endfor statements, accumulating all the statements between 78 * the initial .for loop and the matching .endfor; 79 * then we evaluate the for loop for each variable in the varlist. 80 * 81 * Note that any nested fors are just passed through; they get handled 82 * recursively in For_Eval when we're expanding the enclosing for in 83 * For_Run. 84 */ 85 86 static int forLevel = 0; /* Nesting level */ 87 88 /* 89 * State of a for loop. 90 */ 91 typedef struct _For { 92 Buffer buf; /* Body of loop */ 93 strlist_t vars; /* Iteration variables */ 94 strlist_t items; /* Substitution items */ 95 char *parse_buf; 96 int short_var; 97 int sub_next; 98 } For; 99 100 static For *accumFor; /* Loop being accumulated */ 101 102 103 104 static char * 105 make_str(const char *ptr, int len) 106 { 107 char *new_ptr; 108 109 new_ptr = bmake_malloc(len + 1); 110 memcpy(new_ptr, ptr, len); 111 new_ptr[len] = 0; 112 return new_ptr; 113 } 114 115 static void 116 For_Free(For *arg) 117 { 118 Buf_Destroy(&arg->buf, TRUE); 119 strlist_clean(&arg->vars); 120 strlist_clean(&arg->items); 121 free(arg->parse_buf); 122 123 free(arg); 124 } 125 126 /*- 127 *----------------------------------------------------------------------- 128 * For_Eval -- 129 * Evaluate the for loop in the passed line. The line 130 * looks like this: 131 * .for <variable> in <varlist> 132 * 133 * Input: 134 * line Line to parse 135 * 136 * Results: 137 * 0: Not a .for statement, parse the line 138 * 1: We found a for loop 139 * -1: A .for statement with a bad syntax error, discard. 140 * 141 * Side Effects: 142 * None. 143 * 144 *----------------------------------------------------------------------- 145 */ 146 int 147 For_Eval(char *line) 148 { 149 For *new_for; 150 char *ptr = line, *sub; 151 int len; 152 int escapes; 153 unsigned char ch; 154 155 /* Skip the '.' and any following whitespace */ 156 for (ptr++; *ptr && isspace((unsigned char) *ptr); ptr++) 157 continue; 158 159 /* 160 * If we are not in a for loop quickly determine if the statement is 161 * a for. 162 */ 163 if (ptr[0] != 'f' || ptr[1] != 'o' || ptr[2] != 'r' || 164 !isspace((unsigned char) ptr[3])) { 165 if (ptr[0] == 'e' && strncmp(ptr+1, "ndfor", 5) == 0) { 166 Parse_Error(PARSE_FATAL, "for-less endfor"); 167 return -1; 168 } 169 return 0; 170 } 171 ptr += 3; 172 173 /* 174 * we found a for loop, and now we are going to parse it. 175 */ 176 177 new_for = bmake_malloc(sizeof *new_for); 178 memset(new_for, 0, sizeof *new_for); 179 180 /* Grab the variables. Terminate on "in". */ 181 for (;; ptr += len) { 182 while (*ptr && isspace((unsigned char) *ptr)) 183 ptr++; 184 if (*ptr == '\0') { 185 Parse_Error(PARSE_FATAL, "missing `in' in for"); 186 For_Free(new_for); 187 return -1; 188 } 189 for (len = 1; ptr[len] && !isspace((unsigned char)ptr[len]); len++) 190 continue; 191 if (len == 2 && ptr[0] == 'i' && ptr[1] == 'n') { 192 ptr += 2; 193 break; 194 } 195 if (len == 1) 196 new_for->short_var = 1; 197 strlist_add_str(&new_for->vars, make_str(ptr, len), len); 198 } 199 200 if (strlist_num(&new_for->vars) == 0) { 201 Parse_Error(PARSE_FATAL, "no iteration variables in for"); 202 For_Free(new_for); 203 return -1; 204 } 205 206 while (*ptr && isspace((unsigned char) *ptr)) 207 ptr++; 208 209 /* 210 * Make a list with the remaining words 211 * The values are substituted as ${:U<value>...} so we must \ escape 212 * characters that break that syntax. 213 * Variables are fully expanded - so it is safe for escape $. 214 * We can't do the escapes here - because we don't know whether 215 * we are substuting into ${...} or $(...). 216 */ 217 sub = Var_Subst(NULL, ptr, VAR_GLOBAL, FALSE); 218 219 for (ptr = sub;; ptr += len) { 220 while (*ptr && isspace((unsigned char)*ptr)) 221 ptr++; 222 if (*ptr == 0) 223 break; 224 escapes = 0; 225 for (len = 0; (ch = ptr[len]) != 0 && !isspace(ch); len++) { 226 if (ch == ':' || ch == '$' || ch == '\\') 227 escapes |= FOR_SUB_ESCAPE_CHAR; 228 else if (ch == ')') 229 escapes |= FOR_SUB_ESCAPE_PAREN; 230 else if (ch == /*{*/ '}') 231 escapes |= FOR_SUB_ESCAPE_BRACE; 232 } 233 strlist_add_str(&new_for->items, make_str(ptr, len), escapes); 234 } 235 236 free(sub); 237 238 if (strlist_num(&new_for->items) % strlist_num(&new_for->vars)) { 239 Parse_Error(PARSE_FATAL, 240 "Wrong number of words in .for substitution list %d %d", 241 strlist_num(&new_for->items), strlist_num(&new_for->vars)); 242 /* 243 * Return 'success' so that the body of the .for loop is accumulated. 244 * Remove all items so that the loop doesn't iterate. 245 */ 246 strlist_clean(&new_for->items); 247 } 248 249 Buf_Init(&new_for->buf, 0); 250 accumFor = new_for; 251 forLevel = 1; 252 return 1; 253 } 254 255 /* 256 * Add another line to a .for loop. 257 * Returns 0 when the matching .endfor is reached. 258 */ 259 260 int 261 For_Accum(char *line) 262 { 263 char *ptr = line; 264 265 if (*ptr == '.') { 266 267 for (ptr++; *ptr && isspace((unsigned char) *ptr); ptr++) 268 continue; 269 270 if (strncmp(ptr, "endfor", 6) == 0 && 271 (isspace((unsigned char) ptr[6]) || !ptr[6])) { 272 if (DEBUG(FOR)) 273 (void)fprintf(debug_file, "For: end for %d\n", forLevel); 274 if (--forLevel <= 0) 275 return 0; 276 } else if (strncmp(ptr, "for", 3) == 0 && 277 isspace((unsigned char) ptr[3])) { 278 forLevel++; 279 if (DEBUG(FOR)) 280 (void)fprintf(debug_file, "For: new loop %d\n", forLevel); 281 } 282 } 283 284 Buf_AddBytes(&accumFor->buf, strlen(line), line); 285 Buf_AddByte(&accumFor->buf, '\n'); 286 return 1; 287 } 288 289 290 /*- 291 *----------------------------------------------------------------------- 292 * For_Run -- 293 * Run the for loop, imitating the actions of an include file 294 * 295 * Results: 296 * None. 297 * 298 * Side Effects: 299 * None. 300 * 301 *----------------------------------------------------------------------- 302 */ 303 304 static int 305 for_var_len(const char *var) 306 { 307 char ch, var_start, var_end; 308 int depth; 309 int len; 310 311 var_start = *var; 312 if (var_start == 0) 313 /* just escape the $ */ 314 return 0; 315 316 if (var_start == '(') 317 var_end = ')'; 318 else if (var_start == '{') 319 var_end = '}'; 320 else 321 /* Single char variable */ 322 return 1; 323 324 depth = 1; 325 for (len = 1; (ch = var[len++]) != 0;) { 326 if (ch == var_start) 327 depth++; 328 else if (ch == var_end && --depth == 0) 329 return len; 330 } 331 332 /* Variable end not found, escape the $ */ 333 return 0; 334 } 335 336 static void 337 for_substitute(Buffer *cmds, strlist_t *items, unsigned int item_no, char ech) 338 { 339 const char *item = strlist_str(items, item_no); 340 int len; 341 char ch; 342 343 /* If there were no escapes, or the only escape is the other variable 344 * terminator, then just substitute the full string */ 345 if (!(strlist_info(items, item_no) & 346 (ech == ')' ? ~FOR_SUB_ESCAPE_BRACE : ~FOR_SUB_ESCAPE_PAREN))) { 347 Buf_AddBytes(cmds, strlen(item), item); 348 return; 349 } 350 351 /* Escape ':', '$', '\\' and 'ech' - removed by :U processing */ 352 while ((ch = *item++) != 0) { 353 if (ch == '$') { 354 len = for_var_len(item); 355 if (len != 0) { 356 Buf_AddBytes(cmds, len + 1, item - 1); 357 item += len; 358 continue; 359 } 360 Buf_AddByte(cmds, '\\'); 361 } else if (ch == ':' || ch == '\\' || ch == ech) 362 Buf_AddByte(cmds, '\\'); 363 Buf_AddByte(cmds, ch); 364 } 365 } 366 367 static char * 368 For_Iterate(void *v_arg) 369 { 370 For *arg = v_arg; 371 int i, len; 372 char *var; 373 char *cp; 374 char *cmd_cp; 375 char *body_end; 376 char ch; 377 Buffer cmds; 378 379 if (arg->sub_next + strlist_num(&arg->vars) > strlist_num(&arg->items)) { 380 /* No more iterations */ 381 For_Free(arg); 382 return NULL; 383 } 384 385 free(arg->parse_buf); 386 arg->parse_buf = NULL; 387 388 /* 389 * Scan the for loop body and replace references to the loop variables 390 * with variable references that expand to the required text. 391 * Using variable expansions ensures that the .for loop can't generate 392 * syntax, and that the later parsing will still see a variable. 393 * We assume that the null variable will never be defined. 394 * 395 * The detection of substitions of the loop control variable is naive. 396 * Many of the modifiers use \ to escape $ (not $) so it is possible 397 * to contrive a makefile where an unwanted substitution happens. 398 */ 399 400 cmd_cp = Buf_GetAll(&arg->buf, &len); 401 body_end = cmd_cp + len; 402 Buf_Init(&cmds, len + 256); 403 for (cp = cmd_cp; (cp = strchr(cp, '$')) != NULL;) { 404 char ech; 405 ch = *++cp; 406 if ((ch == '(' && (ech = ')')) || (ch == '{' && (ech = '}'))) { 407 cp++; 408 /* Check variable name against the .for loop variables */ 409 STRLIST_FOREACH(var, &arg->vars, i) { 410 len = strlist_info(&arg->vars, i); 411 if (memcmp(cp, var, len) != 0) 412 continue; 413 if (cp[len] != ':' && cp[len] != ech && cp[len] != '\\') 414 continue; 415 /* Found a variable match. Replace with :U<value> */ 416 Buf_AddBytes(&cmds, cp - cmd_cp, cmd_cp); 417 Buf_AddBytes(&cmds, 2, ":U"); 418 cp += len; 419 cmd_cp = cp; 420 for_substitute(&cmds, &arg->items, arg->sub_next + i, ech); 421 break; 422 } 423 continue; 424 } 425 if (ch == 0) 426 break; 427 /* Probably a single character name, ignore $$ and stupid ones. {*/ 428 if (!arg->short_var || strchr("}):$", ch) != NULL) { 429 cp++; 430 continue; 431 } 432 STRLIST_FOREACH(var, &arg->vars, i) { 433 if (var[0] != ch || var[1] != 0) 434 continue; 435 /* Found a variable match. Replace with ${:U<value>} */ 436 Buf_AddBytes(&cmds, cp - cmd_cp, cmd_cp); 437 Buf_AddBytes(&cmds, 3, "{:U"); 438 cmd_cp = ++cp; 439 for_substitute(&cmds, &arg->items, arg->sub_next + i, /*{*/ '}'); 440 Buf_AddBytes(&cmds, 1, "}"); 441 break; 442 } 443 } 444 Buf_AddBytes(&cmds, body_end - cmd_cp, cmd_cp); 445 446 cp = Buf_Destroy(&cmds, FALSE); 447 if (DEBUG(FOR)) 448 (void)fprintf(debug_file, "For: loop body:\n%s", cp); 449 450 arg->sub_next += strlist_num(&arg->vars); 451 452 arg->parse_buf = cp; 453 return cp; 454 } 455 456 void 457 For_Run(int lineno) 458 { 459 For *arg; 460 461 arg = accumFor; 462 accumFor = NULL; 463 464 if (strlist_num(&arg->items) == 0) { 465 /* Nothing to expand - possibly due to an earlier syntax error. */ 466 For_Free(arg); 467 return; 468 } 469 470 Parse_SetInput(NULL, lineno, -1, For_Iterate, arg); 471 } 472