1 /*- 2 * SPDX-License-Identifier: BSD-4-Clause 3 * 4 * Copyright (c) 1985 Sun Microsystems, Inc. 5 * Copyright (c) 1980, 1993 6 * The Regents of the University of California. All rights reserved. 7 * All rights reserved. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 3. All advertising materials mentioning features or use of this software 18 * must display the following acknowledgement: 19 * This product includes software developed by the University of 20 * California, Berkeley and its contributors. 21 * 4. Neither the name of the University nor the names of its contributors 22 * may be used to endorse or promote products derived from this software 23 * without specific prior written permission. 24 * 25 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 26 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 27 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 28 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 29 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 30 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 31 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 32 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 33 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 34 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 35 * SUCH DAMAGE. 36 */ 37 38 #if 0 39 #ifndef lint 40 static char sccsid[] = "@(#)parse.c 8.1 (Berkeley) 6/6/93"; 41 #endif /* not lint */ 42 #endif 43 44 #include <sys/cdefs.h> 45 __FBSDID("$FreeBSD$"); 46 47 #include <err.h> 48 #include <stdio.h> 49 #include "indent_globs.h" 50 #include "indent_codes.h" 51 #include "indent.h" 52 53 /* Globals */ 54 int break_comma; 55 float case_ind; 56 57 static void reduce(void); 58 59 void 60 parse(int tk) /* tk: the code for the construct scanned */ 61 { 62 int i; 63 64 #ifdef debug 65 printf("%2d - %s\n", tk, token); 66 #endif 67 68 while (ps.p_stack[ps.tos] == ifhead && tk != elselit) { 69 /* true if we have an if without an else */ 70 ps.p_stack[ps.tos] = stmt; /* apply the if(..) stmt ::= stmt 71 * reduction */ 72 reduce(); /* see if this allows any reduction */ 73 } 74 75 76 switch (tk) { /* go on and figure out what to do with the 77 * input */ 78 79 case decl: /* scanned a declaration word */ 80 ps.search_brace = opt.btype_2; 81 /* indicate that following brace should be on same line */ 82 if (ps.p_stack[ps.tos] != decl) { /* only put one declaration 83 * onto stack */ 84 break_comma = true; /* while in declaration, newline should be 85 * forced after comma */ 86 ps.p_stack[++ps.tos] = decl; 87 ps.il[ps.tos] = ps.i_l_follow; 88 89 if (opt.ljust_decl) {/* only do if we want left justified 90 * declarations */ 91 ps.ind_level = 0; 92 for (i = ps.tos - 1; i > 0; --i) 93 if (ps.p_stack[i] == decl) 94 ++ps.ind_level; /* indentation is number of 95 * declaration levels deep we are */ 96 ps.i_l_follow = ps.ind_level; 97 } 98 } 99 break; 100 101 case ifstmt: /* scanned if (...) */ 102 if (ps.p_stack[ps.tos] == elsehead && opt.else_if) /* "else if ..." */ 103 /* 104 * Note that the stack pointer here is decremented, effectively 105 * reducing "else if" to "if". This saves a lot of stack space 106 * in case of a long "if-else-if ... else-if" sequence. 107 */ 108 ps.i_l_follow = ps.il[ps.tos--]; 109 /* the rest is the same as for dolit and forstmt */ 110 /* FALLTHROUGH */ 111 case dolit: /* 'do' */ 112 case forstmt: /* for (...) */ 113 ps.p_stack[++ps.tos] = tk; 114 ps.il[ps.tos] = ps.ind_level = ps.i_l_follow; 115 ++ps.i_l_follow; /* subsequent statements should be indented 1 */ 116 ps.search_brace = opt.btype_2; 117 break; 118 119 case lbrace: /* scanned { */ 120 break_comma = false; /* don't break comma in an initial list */ 121 if (ps.p_stack[ps.tos] == stmt || ps.p_stack[ps.tos] == decl 122 || ps.p_stack[ps.tos] == stmtl) 123 ++ps.i_l_follow; /* it is a random, isolated stmt group or a 124 * declaration */ 125 else { 126 if (s_code == e_code) { 127 /* 128 * only do this if there is nothing on the line 129 */ 130 --ps.ind_level; 131 /* 132 * it is a group as part of a while, for, etc. 133 */ 134 if (ps.p_stack[ps.tos] == swstmt && opt.case_indent >= 1) 135 --ps.ind_level; 136 /* 137 * for a switch, brace should be two levels out from the code 138 */ 139 } 140 } 141 142 ps.p_stack[++ps.tos] = lbrace; 143 ps.il[ps.tos] = ps.ind_level; 144 ps.p_stack[++ps.tos] = stmt; 145 /* allow null stmt between braces */ 146 ps.il[ps.tos] = ps.i_l_follow; 147 break; 148 149 case whilestmt: /* scanned while (...) */ 150 if (ps.p_stack[ps.tos] == dohead) { 151 /* it is matched with do stmt */ 152 ps.ind_level = ps.i_l_follow = ps.il[ps.tos]; 153 ps.p_stack[++ps.tos] = whilestmt; 154 ps.il[ps.tos] = ps.ind_level = ps.i_l_follow; 155 } 156 else { /* it is a while loop */ 157 ps.p_stack[++ps.tos] = whilestmt; 158 ps.il[ps.tos] = ps.i_l_follow; 159 ++ps.i_l_follow; 160 ps.search_brace = opt.btype_2; 161 } 162 163 break; 164 165 case elselit: /* scanned an else */ 166 167 if (ps.p_stack[ps.tos] != ifhead) 168 diag2(1, "Unmatched 'else'"); 169 else { 170 ps.ind_level = ps.il[ps.tos]; /* indentation for else should 171 * be same as for if */ 172 ps.i_l_follow = ps.ind_level + 1; /* everything following should 173 * be in 1 level */ 174 ps.p_stack[ps.tos] = elsehead; 175 /* remember if with else */ 176 ps.search_brace = opt.btype_2 | opt.else_if; 177 } 178 break; 179 180 case rbrace: /* scanned a } */ 181 /* stack should have <lbrace> <stmt> or <lbrace> <stmtl> */ 182 if (ps.tos > 0 && ps.p_stack[ps.tos - 1] == lbrace) { 183 ps.ind_level = ps.i_l_follow = ps.il[--ps.tos]; 184 ps.p_stack[ps.tos] = stmt; 185 } 186 else 187 diag2(1, "Statement nesting error"); 188 break; 189 190 case swstmt: /* had switch (...) */ 191 ps.p_stack[++ps.tos] = swstmt; 192 ps.cstk[ps.tos] = case_ind; 193 /* save current case indent level */ 194 ps.il[ps.tos] = ps.i_l_follow; 195 case_ind = ps.i_l_follow + opt.case_indent; /* cases should be one 196 * level down from 197 * switch */ 198 ps.i_l_follow += opt.case_indent + 1; /* statements should be two 199 * levels in */ 200 ps.search_brace = opt.btype_2; 201 break; 202 203 case semicolon: /* this indicates a simple stmt */ 204 break_comma = false; /* turn off flag to break after commas in a 205 * declaration */ 206 ps.p_stack[++ps.tos] = stmt; 207 ps.il[ps.tos] = ps.ind_level; 208 break; 209 210 default: /* this is an error */ 211 diag2(1, "Unknown code to parser"); 212 return; 213 214 215 } /* end of switch */ 216 217 if (ps.tos >= STACKSIZE - 1) 218 errx(1, "Parser stack overflow"); 219 220 reduce(); /* see if any reduction can be done */ 221 222 #ifdef debug 223 for (i = 1; i <= ps.tos; ++i) 224 printf("(%d %d)", ps.p_stack[i], ps.il[i]); 225 printf("\n"); 226 #endif 227 228 return; 229 } 230 231 /* 232 * NAME: reduce 233 * 234 * FUNCTION: Implements the reduce part of the parsing algorithm 235 * 236 * ALGORITHM: The following reductions are done. Reductions are repeated 237 * until no more are possible. 238 * 239 * Old TOS New TOS 240 * <stmt> <stmt> <stmtl> 241 * <stmtl> <stmt> <stmtl> 242 * do <stmt> "dostmt" 243 * if <stmt> "ifstmt" 244 * switch <stmt> <stmt> 245 * decl <stmt> <stmt> 246 * "ifelse" <stmt> <stmt> 247 * for <stmt> <stmt> 248 * while <stmt> <stmt> 249 * "dostmt" while <stmt> 250 * 251 * On each reduction, ps.i_l_follow (the indentation for the following line) 252 * is set to the indentation level associated with the old TOS. 253 * 254 * PARAMETERS: None 255 * 256 * RETURNS: Nothing 257 * 258 * GLOBALS: ps.cstk ps.i_l_follow = ps.il ps.p_stack = ps.tos = 259 * 260 * CALLS: None 261 * 262 * CALLED BY: parse 263 * 264 * HISTORY: initial coding November 1976 D A Willcox of CAC 265 * 266 */ 267 /*----------------------------------------------*\ 268 | REDUCTION PHASE | 269 \*----------------------------------------------*/ 270 static void 271 reduce(void) 272 { 273 int i; 274 275 for (;;) { /* keep looping until there is nothing left to 276 * reduce */ 277 278 switch (ps.p_stack[ps.tos]) { 279 280 case stmt: 281 switch (ps.p_stack[ps.tos - 1]) { 282 283 case stmt: 284 case stmtl: 285 /* stmtl stmt or stmt stmt */ 286 ps.p_stack[--ps.tos] = stmtl; 287 break; 288 289 case dolit: /* <do> <stmt> */ 290 ps.p_stack[--ps.tos] = dohead; 291 ps.i_l_follow = ps.il[ps.tos]; 292 break; 293 294 case ifstmt: 295 /* <if> <stmt> */ 296 ps.p_stack[--ps.tos] = ifhead; 297 for (i = ps.tos - 1; 298 ( 299 ps.p_stack[i] != stmt 300 && 301 ps.p_stack[i] != stmtl 302 && 303 ps.p_stack[i] != lbrace 304 ); 305 --i); 306 ps.i_l_follow = ps.il[i]; 307 /* 308 * for the time being, we will assume that there is no else on 309 * this if, and set the indentation level accordingly. If an 310 * else is scanned, it will be fixed up later 311 */ 312 break; 313 314 case swstmt: 315 /* <switch> <stmt> */ 316 case_ind = ps.cstk[ps.tos - 1]; 317 /* FALLTHROUGH */ 318 case decl: /* finish of a declaration */ 319 case elsehead: 320 /* <<if> <stmt> else> <stmt> */ 321 case forstmt: 322 /* <for> <stmt> */ 323 case whilestmt: 324 /* <while> <stmt> */ 325 ps.p_stack[--ps.tos] = stmt; 326 ps.i_l_follow = ps.il[ps.tos]; 327 break; 328 329 default: /* <anything else> <stmt> */ 330 return; 331 332 } /* end of section for <stmt> on top of stack */ 333 break; 334 335 case whilestmt: /* while (...) on top */ 336 if (ps.p_stack[ps.tos - 1] == dohead) { 337 /* it is termination of a do while */ 338 ps.tos -= 2; 339 break; 340 } 341 else 342 return; 343 344 default: /* anything else on top */ 345 return; 346 347 } 348 } 349 } 350