1 /* 2 * Copyright (c) 1985 Sun Microsystems, Inc. 3 * Copyright (c) 1980, 1993 4 * The Regents of the University of California. All rights reserved. 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. All advertising materials mentioning features or use of this software 16 * must display the following acknowledgement: 17 * This product includes software developed by the University of 18 * California, Berkeley and its contributors. 19 * 4. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 * 35 * @(#)parse.c 8.1 (Berkeley) 6/6/93 36 * $FreeBSD: src/usr.bin/indent/parse.c,v 1.3.2.3 2001/12/06 19:28:47 schweikh Exp $ 37 * $DragonFly: src/usr.bin/indent/parse.c,v 1.3 2005/04/10 20:55:38 drhodus Exp $ 38 */ 39 #if 0 40 #endif 41 42 #include <stdio.h> 43 #include "indent_globs.h" 44 #include "indent_codes.h" 45 #include "indent.h" 46 47 static void reduce(void); 48 49 void 50 parse(int tk) /* tk: the code for the construct scanned */ 51 { 52 int i; 53 54 #ifdef debug 55 printf("%2d - %s\n", tk, token); 56 #endif 57 58 while (ps.p_stack[ps.tos] == ifhead && tk != elselit) { 59 /* true if we have an if without an else */ 60 ps.p_stack[ps.tos] = stmt; /* apply the if(..) stmt ::= stmt 61 * reduction */ 62 reduce(); /* see if this allows any reduction */ 63 } 64 65 66 switch (tk) { /* go on and figure out what to do with the 67 * input */ 68 69 case decl: /* scanned a declaration word */ 70 ps.search_brace = btype_2; 71 /* indicate that following brace should be on same line */ 72 if (ps.p_stack[ps.tos] != decl) { /* only put one declaration 73 * onto stack */ 74 break_comma = true; /* while in declaration, newline should be 75 * forced after comma */ 76 ps.p_stack[++ps.tos] = decl; 77 ps.il[ps.tos] = ps.i_l_follow; 78 79 if (ps.ljust_decl) {/* only do if we want left justified 80 * declarations */ 81 ps.ind_level = 0; 82 for (i = ps.tos - 1; i > 0; --i) 83 if (ps.p_stack[i] == decl) 84 ++ps.ind_level; /* indentation is number of 85 * declaration levels deep we are */ 86 ps.i_l_follow = ps.ind_level; 87 } 88 } 89 break; 90 91 case ifstmt: /* scanned if (...) */ 92 if (ps.p_stack[ps.tos] == elsehead && ps.else_if) /* "else if ..." */ 93 ps.i_l_follow = ps.il[ps.tos]; 94 case dolit: /* 'do' */ 95 case forstmt: /* for (...) */ 96 ps.p_stack[++ps.tos] = tk; 97 ps.il[ps.tos] = ps.ind_level = ps.i_l_follow; 98 ++ps.i_l_follow; /* subsequent statements should be indented 1 */ 99 ps.search_brace = btype_2; 100 break; 101 102 case lbrace: /* scanned { */ 103 break_comma = false; /* don't break comma in an initial list */ 104 if (ps.p_stack[ps.tos] == stmt || ps.p_stack[ps.tos] == decl 105 || ps.p_stack[ps.tos] == stmtl) 106 ++ps.i_l_follow; /* it is a random, isolated stmt group or a 107 * declaration */ 108 else { 109 if (s_code == e_code) { 110 /* 111 * only do this if there is nothing on the line 112 */ 113 --ps.ind_level; 114 /* 115 * it is a group as part of a while, for, etc. 116 */ 117 if (ps.p_stack[ps.tos] == swstmt && ps.case_indent >= 1) 118 --ps.ind_level; 119 /* 120 * for a switch, brace should be two levels out from the code 121 */ 122 } 123 } 124 125 ps.p_stack[++ps.tos] = lbrace; 126 ps.il[ps.tos] = ps.ind_level; 127 ps.p_stack[++ps.tos] = stmt; 128 /* allow null stmt between braces */ 129 ps.il[ps.tos] = ps.i_l_follow; 130 break; 131 132 case whilestmt: /* scanned while (...) */ 133 if (ps.p_stack[ps.tos] == dohead) { 134 /* it is matched with do stmt */ 135 ps.ind_level = ps.i_l_follow = ps.il[ps.tos]; 136 ps.p_stack[++ps.tos] = whilestmt; 137 ps.il[ps.tos] = ps.ind_level = ps.i_l_follow; 138 } 139 else { /* it is a while loop */ 140 ps.p_stack[++ps.tos] = whilestmt; 141 ps.il[ps.tos] = ps.i_l_follow; 142 ++ps.i_l_follow; 143 ps.search_brace = btype_2; 144 } 145 146 break; 147 148 case elselit: /* scanned an else */ 149 150 if (ps.p_stack[ps.tos] != ifhead) 151 diag2(1, "Unmatched 'else'"); 152 else { 153 ps.ind_level = ps.il[ps.tos]; /* indentation for else should 154 * be same as for if */ 155 ps.i_l_follow = ps.ind_level + 1; /* everything following should 156 * be in 1 level */ 157 ps.p_stack[ps.tos] = elsehead; 158 /* remember if with else */ 159 ps.search_brace = btype_2 | ps.else_if; 160 } 161 break; 162 163 case rbrace: /* scanned a } */ 164 /* stack should have <lbrace> <stmt> or <lbrace> <stmtl> */ 165 if (ps.p_stack[ps.tos - 1] == lbrace) { 166 ps.ind_level = ps.i_l_follow = ps.il[--ps.tos]; 167 ps.p_stack[ps.tos] = stmt; 168 } 169 else 170 diag2(1, "Stmt nesting error."); 171 break; 172 173 case swstmt: /* had switch (...) */ 174 ps.p_stack[++ps.tos] = swstmt; 175 ps.cstk[ps.tos] = case_ind; 176 /* save current case indent level */ 177 ps.il[ps.tos] = ps.i_l_follow; 178 case_ind = ps.i_l_follow + ps.case_indent; /* cases should be one 179 * level down from 180 * switch */ 181 ps.i_l_follow += ps.case_indent + 1; /* statements should be two 182 * levels in */ 183 ps.search_brace = btype_2; 184 break; 185 186 case semicolon: /* this indicates a simple stmt */ 187 break_comma = false; /* turn off flag to break after commas in a 188 * declaration */ 189 ps.p_stack[++ps.tos] = stmt; 190 ps.il[ps.tos] = ps.ind_level; 191 break; 192 193 default: /* this is an error */ 194 diag2(1, "Unknown code to parser"); 195 return; 196 197 198 } /* end of switch */ 199 200 reduce(); /* see if any reduction can be done */ 201 202 #ifdef debug 203 for (i = 1; i <= ps.tos; ++i) 204 printf("(%d %d)", ps.p_stack[i], ps.il[i]); 205 printf("\n"); 206 #endif 207 208 return; 209 } 210 211 /* 212 * NAME: reduce 213 * 214 * FUNCTION: Implements the reduce part of the parsing algorithm 215 * 216 * ALGORITHM: The following reductions are done. Reductions are repeated 217 * until no more are possible. 218 * 219 * Old TOS New TOS 220 * <stmt> <stmt> <stmtl> 221 * <stmtl> <stmt> <stmtl> 222 * do <stmt> "dostmt" 223 * if <stmt> "ifstmt" 224 * switch <stmt> <stmt> 225 * decl <stmt> <stmt> 226 * "ifelse" <stmt> <stmt> 227 * for <stmt> <stmt> 228 * while <stmt> <stmt> 229 * "dostmt" while <stmt> 230 * 231 * On each reduction, ps.i_l_follow (the indentation for the following line) 232 * is set to the indentation level associated with the old TOS. 233 * 234 * PARAMETERS: None 235 * 236 * RETURNS: Nothing 237 * 238 * GLOBALS: ps.cstk ps.i_l_follow = ps.il ps.p_stack = ps.tos = 239 * 240 * CALLS: None 241 * 242 * CALLED BY: parse 243 * 244 * HISTORY: initial coding November 1976 D A Willcox of CAC 245 * 246 */ 247 /*----------------------------------------------*\ 248 | REDUCTION PHASE | 249 \*----------------------------------------------*/ 250 static void 251 reduce(void) 252 { 253 int i; 254 255 for (;;) { /* keep looping until there is nothing left to 256 * reduce */ 257 258 switch (ps.p_stack[ps.tos]) { 259 260 case stmt: 261 switch (ps.p_stack[ps.tos - 1]) { 262 263 case stmt: 264 case stmtl: 265 /* stmtl stmt or stmt stmt */ 266 ps.p_stack[--ps.tos] = stmtl; 267 break; 268 269 case dolit: /* <do> <stmt> */ 270 ps.p_stack[--ps.tos] = dohead; 271 ps.i_l_follow = ps.il[ps.tos]; 272 break; 273 274 case ifstmt: 275 /* <if> <stmt> */ 276 ps.p_stack[--ps.tos] = ifhead; 277 for (i = ps.tos - 1; 278 ( 279 ps.p_stack[i] != stmt 280 && 281 ps.p_stack[i] != stmtl 282 && 283 ps.p_stack[i] != lbrace 284 ); 285 --i); 286 ps.i_l_follow = ps.il[i]; 287 /* 288 * for the time being, we will assume that there is no else on 289 * this if, and set the indentation level accordingly. If an 290 * else is scanned, it will be fixed up later 291 */ 292 break; 293 294 case swstmt: 295 /* <switch> <stmt> */ 296 case_ind = ps.cstk[ps.tos - 1]; 297 298 case decl: /* finish of a declaration */ 299 case elsehead: 300 /* <<if> <stmt> else> <stmt> */ 301 case forstmt: 302 /* <for> <stmt> */ 303 case whilestmt: 304 /* <while> <stmt> */ 305 ps.p_stack[--ps.tos] = stmt; 306 ps.i_l_follow = ps.il[ps.tos]; 307 break; 308 309 default: /* <anything else> <stmt> */ 310 return; 311 312 } /* end of section for <stmt> on top of stack */ 313 break; 314 315 case whilestmt: /* while (...) on top */ 316 if (ps.p_stack[ps.tos - 1] == dohead) { 317 /* it is termination of a do while */ 318 ps.tos -= 2; 319 break; 320 } 321 else 322 return; 323 324 default: /* anything else on top */ 325 return; 326 327 } 328 } 329 } 330