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 #if 0 36 #ifndef lint 37 static char sccsid[] = "@(#)parse.c 8.1 (Berkeley) 6/6/93"; 38 static const char rcsid[] = 39 "$FreeBSD: src/usr.bin/indent/parse.c,v 1.3.2.3 2001/12/06 19:28:47 schweikh Exp $"; 40 #endif /* not lint */ 41 #endif 42 43 #include <stdio.h> 44 #include "indent_globs.h" 45 #include "indent_codes.h" 46 #include "indent.h" 47 48 static void reduce(void); 49 50 void 51 parse(int tk) /* tk: the code for the construct scanned */ 52 { 53 int i; 54 55 #ifdef debug 56 printf("%2d - %s\n", tk, token); 57 #endif 58 59 while (ps.p_stack[ps.tos] == ifhead && tk != elselit) { 60 /* true if we have an if without an else */ 61 ps.p_stack[ps.tos] = stmt; /* apply the if(..) stmt ::= stmt 62 * reduction */ 63 reduce(); /* see if this allows any reduction */ 64 } 65 66 67 switch (tk) { /* go on and figure out what to do with the 68 * input */ 69 70 case decl: /* scanned a declaration word */ 71 ps.search_brace = btype_2; 72 /* indicate that following brace should be on same line */ 73 if (ps.p_stack[ps.tos] != decl) { /* only put one declaration 74 * onto stack */ 75 break_comma = true; /* while in declaration, newline should be 76 * forced after comma */ 77 ps.p_stack[++ps.tos] = decl; 78 ps.il[ps.tos] = ps.i_l_follow; 79 80 if (ps.ljust_decl) {/* only do if we want left justified 81 * declarations */ 82 ps.ind_level = 0; 83 for (i = ps.tos - 1; i > 0; --i) 84 if (ps.p_stack[i] == decl) 85 ++ps.ind_level; /* indentation is number of 86 * declaration levels deep we are */ 87 ps.i_l_follow = ps.ind_level; 88 } 89 } 90 break; 91 92 case ifstmt: /* scanned if (...) */ 93 if (ps.p_stack[ps.tos] == elsehead && ps.else_if) /* "else if ..." */ 94 ps.i_l_follow = ps.il[ps.tos]; 95 case dolit: /* 'do' */ 96 case forstmt: /* for (...) */ 97 ps.p_stack[++ps.tos] = tk; 98 ps.il[ps.tos] = ps.ind_level = ps.i_l_follow; 99 ++ps.i_l_follow; /* subsequent statements should be indented 1 */ 100 ps.search_brace = btype_2; 101 break; 102 103 case lbrace: /* scanned { */ 104 break_comma = false; /* don't break comma in an initial list */ 105 if (ps.p_stack[ps.tos] == stmt || ps.p_stack[ps.tos] == decl 106 || ps.p_stack[ps.tos] == stmtl) 107 ++ps.i_l_follow; /* it is a random, isolated stmt group or a 108 * declaration */ 109 else { 110 if (s_code == e_code) { 111 /* 112 * only do this if there is nothing on the line 113 */ 114 --ps.ind_level; 115 /* 116 * it is a group as part of a while, for, etc. 117 */ 118 if (ps.p_stack[ps.tos] == swstmt && ps.case_indent >= 1) 119 --ps.ind_level; 120 /* 121 * for a switch, brace should be two levels out from the code 122 */ 123 } 124 } 125 126 ps.p_stack[++ps.tos] = lbrace; 127 ps.il[ps.tos] = ps.ind_level; 128 ps.p_stack[++ps.tos] = stmt; 129 /* allow null stmt between braces */ 130 ps.il[ps.tos] = ps.i_l_follow; 131 break; 132 133 case whilestmt: /* scanned while (...) */ 134 if (ps.p_stack[ps.tos] == dohead) { 135 /* it is matched with do stmt */ 136 ps.ind_level = ps.i_l_follow = ps.il[ps.tos]; 137 ps.p_stack[++ps.tos] = whilestmt; 138 ps.il[ps.tos] = ps.ind_level = ps.i_l_follow; 139 } 140 else { /* it is a while loop */ 141 ps.p_stack[++ps.tos] = whilestmt; 142 ps.il[ps.tos] = ps.i_l_follow; 143 ++ps.i_l_follow; 144 ps.search_brace = btype_2; 145 } 146 147 break; 148 149 case elselit: /* scanned an else */ 150 151 if (ps.p_stack[ps.tos] != ifhead) 152 diag2(1, "Unmatched 'else'"); 153 else { 154 ps.ind_level = ps.il[ps.tos]; /* indentation for else should 155 * be same as for if */ 156 ps.i_l_follow = ps.ind_level + 1; /* everything following should 157 * be in 1 level */ 158 ps.p_stack[ps.tos] = elsehead; 159 /* remember if with else */ 160 ps.search_brace = btype_2 | ps.else_if; 161 } 162 break; 163 164 case rbrace: /* scanned a } */ 165 /* stack should have <lbrace> <stmt> or <lbrace> <stmtl> */ 166 if (ps.p_stack[ps.tos - 1] == lbrace) { 167 ps.ind_level = ps.i_l_follow = ps.il[--ps.tos]; 168 ps.p_stack[ps.tos] = stmt; 169 } 170 else 171 diag2(1, "Stmt nesting error."); 172 break; 173 174 case swstmt: /* had switch (...) */ 175 ps.p_stack[++ps.tos] = swstmt; 176 ps.cstk[ps.tos] = case_ind; 177 /* save current case indent level */ 178 ps.il[ps.tos] = ps.i_l_follow; 179 case_ind = ps.i_l_follow + ps.case_indent; /* cases should be one 180 * level down from 181 * switch */ 182 ps.i_l_follow += ps.case_indent + 1; /* statements should be two 183 * levels in */ 184 ps.search_brace = btype_2; 185 break; 186 187 case semicolon: /* this indicates a simple stmt */ 188 break_comma = false; /* turn off flag to break after commas in a 189 * declaration */ 190 ps.p_stack[++ps.tos] = stmt; 191 ps.il[ps.tos] = ps.ind_level; 192 break; 193 194 default: /* this is an error */ 195 diag2(1, "Unknown code to parser"); 196 return; 197 198 199 } /* end of switch */ 200 201 reduce(); /* see if any reduction can be done */ 202 203 #ifdef debug 204 for (i = 1; i <= ps.tos; ++i) 205 printf("(%d %d)", ps.p_stack[i], ps.il[i]); 206 printf("\n"); 207 #endif 208 209 return; 210 } 211 212 /* 213 * NAME: reduce 214 * 215 * FUNCTION: Implements the reduce part of the parsing algorithm 216 * 217 * ALGORITHM: The following reductions are done. Reductions are repeated 218 * until no more are possible. 219 * 220 * Old TOS New TOS 221 * <stmt> <stmt> <stmtl> 222 * <stmtl> <stmt> <stmtl> 223 * do <stmt> "dostmt" 224 * if <stmt> "ifstmt" 225 * switch <stmt> <stmt> 226 * decl <stmt> <stmt> 227 * "ifelse" <stmt> <stmt> 228 * for <stmt> <stmt> 229 * while <stmt> <stmt> 230 * "dostmt" while <stmt> 231 * 232 * On each reduction, ps.i_l_follow (the indentation for the following line) 233 * is set to the indentation level associated with the old TOS. 234 * 235 * PARAMETERS: None 236 * 237 * RETURNS: Nothing 238 * 239 * GLOBALS: ps.cstk ps.i_l_follow = ps.il ps.p_stack = ps.tos = 240 * 241 * CALLS: None 242 * 243 * CALLED BY: parse 244 * 245 * HISTORY: initial coding November 1976 D A Willcox of CAC 246 * 247 */ 248 /*----------------------------------------------*\ 249 | REDUCTION PHASE | 250 \*----------------------------------------------*/ 251 static void 252 reduce(void) 253 { 254 register int i; 255 256 for (;;) { /* keep looping until there is nothing left to 257 * reduce */ 258 259 switch (ps.p_stack[ps.tos]) { 260 261 case stmt: 262 switch (ps.p_stack[ps.tos - 1]) { 263 264 case stmt: 265 case stmtl: 266 /* stmtl stmt or stmt stmt */ 267 ps.p_stack[--ps.tos] = stmtl; 268 break; 269 270 case dolit: /* <do> <stmt> */ 271 ps.p_stack[--ps.tos] = dohead; 272 ps.i_l_follow = ps.il[ps.tos]; 273 break; 274 275 case ifstmt: 276 /* <if> <stmt> */ 277 ps.p_stack[--ps.tos] = ifhead; 278 for (i = ps.tos - 1; 279 ( 280 ps.p_stack[i] != stmt 281 && 282 ps.p_stack[i] != stmtl 283 && 284 ps.p_stack[i] != lbrace 285 ); 286 --i); 287 ps.i_l_follow = ps.il[i]; 288 /* 289 * for the time being, we will assume that there is no else on 290 * this if, and set the indentation level accordingly. If an 291 * else is scanned, it will be fixed up later 292 */ 293 break; 294 295 case swstmt: 296 /* <switch> <stmt> */ 297 case_ind = ps.cstk[ps.tos - 1]; 298 299 case decl: /* finish of a declaration */ 300 case elsehead: 301 /* <<if> <stmt> else> <stmt> */ 302 case forstmt: 303 /* <for> <stmt> */ 304 case whilestmt: 305 /* <while> <stmt> */ 306 ps.p_stack[--ps.tos] = stmt; 307 ps.i_l_follow = ps.il[ps.tos]; 308 break; 309 310 default: /* <anything else> <stmt> */ 311 return; 312 313 } /* end of section for <stmt> on top of stack */ 314 break; 315 316 case whilestmt: /* while (...) on top */ 317 if (ps.p_stack[ps.tos - 1] == dohead) { 318 /* it is termination of a do while */ 319 ps.tos -= 2; 320 break; 321 } 322 else 323 return; 324 325 default: /* anything else on top */ 326 return; 327 328 } 329 } 330 } 331