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 #include <err.h> 46 #include <stdio.h> 47 #include "indent_globs.h" 48 #include "indent_codes.h" 49 #include "indent.h" 50 51 /* Globals */ 52 int break_comma; 53 float case_ind; 54 55 static void reduce(void); 56 57 void 58 parse(int tk) /* tk: the code for the construct scanned */ 59 { 60 int i; 61 62 #ifdef debug 63 printf("%2d - %s\n", tk, token); 64 #endif 65 66 while (ps.p_stack[ps.tos] == ifhead && tk != elselit) { 67 /* true if we have an if without an else */ 68 ps.p_stack[ps.tos] = stmt; /* apply the if(..) stmt ::= stmt 69 * reduction */ 70 reduce(); /* see if this allows any reduction */ 71 } 72 73 74 switch (tk) { /* go on and figure out what to do with the 75 * input */ 76 77 case decl: /* scanned a declaration word */ 78 ps.search_brace = opt.btype_2; 79 /* indicate that following brace should be on same line */ 80 if (ps.p_stack[ps.tos] != decl) { /* only put one declaration 81 * onto stack */ 82 break_comma = true; /* while in declaration, newline should be 83 * forced after comma */ 84 ps.p_stack[++ps.tos] = decl; 85 ps.il[ps.tos] = ps.i_l_follow; 86 87 if (opt.ljust_decl) {/* only do if we want left justified 88 * declarations */ 89 ps.ind_level = 0; 90 for (i = ps.tos - 1; i > 0; --i) 91 if (ps.p_stack[i] == decl) 92 ++ps.ind_level; /* indentation is number of 93 * declaration levels deep we are */ 94 ps.i_l_follow = ps.ind_level; 95 } 96 } 97 break; 98 99 case ifstmt: /* scanned if (...) */ 100 if (ps.p_stack[ps.tos] == elsehead && opt.else_if) /* "else if ..." */ 101 /* 102 * Note that the stack pointer here is decremented, effectively 103 * reducing "else if" to "if". This saves a lot of stack space 104 * in case of a long "if-else-if ... else-if" sequence. 105 */ 106 ps.i_l_follow = ps.il[ps.tos--]; 107 /* the rest is the same as for dolit and forstmt */ 108 /* FALLTHROUGH */ 109 case dolit: /* 'do' */ 110 case forstmt: /* for (...) */ 111 ps.p_stack[++ps.tos] = tk; 112 ps.il[ps.tos] = ps.ind_level = ps.i_l_follow; 113 ++ps.i_l_follow; /* subsequent statements should be indented 1 */ 114 ps.search_brace = opt.btype_2; 115 break; 116 117 case lbrace: /* scanned { */ 118 break_comma = false; /* don't break comma in an initial list */ 119 if (ps.p_stack[ps.tos] == stmt || ps.p_stack[ps.tos] == decl 120 || ps.p_stack[ps.tos] == stmtl) 121 ++ps.i_l_follow; /* it is a random, isolated stmt group or a 122 * declaration */ 123 else { 124 if (s_code == e_code) { 125 /* 126 * only do this if there is nothing on the line 127 */ 128 --ps.ind_level; 129 /* 130 * it is a group as part of a while, for, etc. 131 */ 132 if (ps.p_stack[ps.tos] == swstmt && opt.case_indent >= 1) 133 --ps.ind_level; 134 /* 135 * for a switch, brace should be two levels out from the code 136 */ 137 } 138 } 139 140 ps.p_stack[++ps.tos] = lbrace; 141 ps.il[ps.tos] = ps.ind_level; 142 ps.p_stack[++ps.tos] = stmt; 143 /* allow null stmt between braces */ 144 ps.il[ps.tos] = ps.i_l_follow; 145 break; 146 147 case whilestmt: /* scanned while (...) */ 148 if (ps.p_stack[ps.tos] == dohead) { 149 /* it is matched with do stmt */ 150 ps.ind_level = ps.i_l_follow = ps.il[ps.tos]; 151 ps.p_stack[++ps.tos] = whilestmt; 152 ps.il[ps.tos] = ps.ind_level = ps.i_l_follow; 153 } 154 else { /* it is a while loop */ 155 ps.p_stack[++ps.tos] = whilestmt; 156 ps.il[ps.tos] = ps.i_l_follow; 157 ++ps.i_l_follow; 158 ps.search_brace = opt.btype_2; 159 } 160 161 break; 162 163 case elselit: /* scanned an else */ 164 165 if (ps.p_stack[ps.tos] != ifhead) 166 diag2(1, "Unmatched 'else'"); 167 else { 168 ps.ind_level = ps.il[ps.tos]; /* indentation for else should 169 * be same as for if */ 170 ps.i_l_follow = ps.ind_level + 1; /* everything following should 171 * be in 1 level */ 172 ps.p_stack[ps.tos] = elsehead; 173 /* remember if with else */ 174 ps.search_brace = opt.btype_2 | opt.else_if; 175 } 176 break; 177 178 case rbrace: /* scanned a } */ 179 /* stack should have <lbrace> <stmt> or <lbrace> <stmtl> */ 180 if (ps.tos > 0 && ps.p_stack[ps.tos - 1] == lbrace) { 181 ps.ind_level = ps.i_l_follow = ps.il[--ps.tos]; 182 ps.p_stack[ps.tos] = stmt; 183 } 184 else 185 diag2(1, "Statement nesting error"); 186 break; 187 188 case swstmt: /* had switch (...) */ 189 ps.p_stack[++ps.tos] = swstmt; 190 ps.cstk[ps.tos] = case_ind; 191 /* save current case indent level */ 192 ps.il[ps.tos] = ps.i_l_follow; 193 case_ind = ps.i_l_follow + opt.case_indent; /* cases should be one 194 * level down from 195 * switch */ 196 ps.i_l_follow += opt.case_indent + 1; /* statements should be two 197 * levels in */ 198 ps.search_brace = opt.btype_2; 199 break; 200 201 case semicolon: /* this indicates a simple stmt */ 202 break_comma = false; /* turn off flag to break after commas in a 203 * declaration */ 204 ps.p_stack[++ps.tos] = stmt; 205 ps.il[ps.tos] = ps.ind_level; 206 break; 207 208 default: /* this is an error */ 209 diag2(1, "Unknown code to parser"); 210 return; 211 212 213 } /* end of switch */ 214 215 if (ps.tos >= STACKSIZE - 1) 216 errx(1, "Parser stack overflow"); 217 218 reduce(); /* see if any reduction can be done */ 219 220 #ifdef debug 221 for (i = 1; i <= ps.tos; ++i) 222 printf("(%d %d)", ps.p_stack[i], ps.il[i]); 223 printf("\n"); 224 #endif 225 226 return; 227 } 228 229 /* 230 * NAME: reduce 231 * 232 * FUNCTION: Implements the reduce part of the parsing algorithm 233 * 234 * ALGORITHM: The following reductions are done. Reductions are repeated 235 * until no more are possible. 236 * 237 * Old TOS New TOS 238 * <stmt> <stmt> <stmtl> 239 * <stmtl> <stmt> <stmtl> 240 * do <stmt> "dostmt" 241 * if <stmt> "ifstmt" 242 * switch <stmt> <stmt> 243 * decl <stmt> <stmt> 244 * "ifelse" <stmt> <stmt> 245 * for <stmt> <stmt> 246 * while <stmt> <stmt> 247 * "dostmt" while <stmt> 248 * 249 * On each reduction, ps.i_l_follow (the indentation for the following line) 250 * is set to the indentation level associated with the old TOS. 251 * 252 * PARAMETERS: None 253 * 254 * RETURNS: Nothing 255 * 256 * GLOBALS: ps.cstk ps.i_l_follow = ps.il ps.p_stack = ps.tos = 257 * 258 * CALLS: None 259 * 260 * CALLED BY: parse 261 * 262 * HISTORY: initial coding November 1976 D A Willcox of CAC 263 * 264 */ 265 /*----------------------------------------------*\ 266 | REDUCTION PHASE | 267 \*----------------------------------------------*/ 268 static void 269 reduce(void) 270 { 271 int i; 272 273 for (;;) { /* keep looping until there is nothing left to 274 * reduce */ 275 276 switch (ps.p_stack[ps.tos]) { 277 278 case stmt: 279 switch (ps.p_stack[ps.tos - 1]) { 280 281 case stmt: 282 case stmtl: 283 /* stmtl stmt or stmt stmt */ 284 ps.p_stack[--ps.tos] = stmtl; 285 break; 286 287 case dolit: /* <do> <stmt> */ 288 ps.p_stack[--ps.tos] = dohead; 289 ps.i_l_follow = ps.il[ps.tos]; 290 break; 291 292 case ifstmt: 293 /* <if> <stmt> */ 294 ps.p_stack[--ps.tos] = ifhead; 295 for (i = ps.tos - 1; 296 ( 297 ps.p_stack[i] != stmt 298 && 299 ps.p_stack[i] != stmtl 300 && 301 ps.p_stack[i] != lbrace 302 ); 303 --i); 304 ps.i_l_follow = ps.il[i]; 305 /* 306 * for the time being, we will assume that there is no else on 307 * this if, and set the indentation level accordingly. If an 308 * else is scanned, it will be fixed up later 309 */ 310 break; 311 312 case swstmt: 313 /* <switch> <stmt> */ 314 case_ind = ps.cstk[ps.tos - 1]; 315 /* FALLTHROUGH */ 316 case decl: /* finish of a declaration */ 317 case elsehead: 318 /* <<if> <stmt> else> <stmt> */ 319 case forstmt: 320 /* <for> <stmt> */ 321 case whilestmt: 322 /* <while> <stmt> */ 323 ps.p_stack[--ps.tos] = stmt; 324 ps.i_l_follow = ps.il[ps.tos]; 325 break; 326 327 default: /* <anything else> <stmt> */ 328 return; 329 330 } /* end of section for <stmt> on top of stack */ 331 break; 332 333 case whilestmt: /* while (...) on top */ 334 if (ps.p_stack[ps.tos - 1] == dohead) { 335 /* it is termination of a do while */ 336 ps.tos -= 2; 337 break; 338 } 339 else 340 return; 341 342 default: /* anything else on top */ 343 return; 344 345 } 346 } 347 } 348