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 36 #if 0 37 #ifndef lint 38 static char sccsid[] = "@(#)parse.c 8.1 (Berkeley) 6/6/93"; 39 #endif /* not lint */ 40 #endif 41 42 #include <sys/cdefs.h> 43 __FBSDID("$FreeBSD$"); 44 45 #include <err.h> 46 #include <stdio.h> 47 #include "indent_globs.h" 48 #include "indent_codes.h" 49 #include "indent.h" 50 51 static void reduce(void); 52 53 void 54 parse(int tk) /* tk: the code for the construct scanned */ 55 { 56 int i; 57 58 #ifdef debug 59 printf("%2d - %s\n", tk, token); 60 #endif 61 62 while (ps.p_stack[ps.tos] == ifhead && tk != elselit) { 63 /* true if we have an if without an else */ 64 ps.p_stack[ps.tos] = stmt; /* apply the if(..) stmt ::= stmt 65 * reduction */ 66 reduce(); /* see if this allows any reduction */ 67 } 68 69 70 switch (tk) { /* go on and figure out what to do with the 71 * input */ 72 73 case decl: /* scanned a declaration word */ 74 ps.search_brace = btype_2; 75 /* indicate that following brace should be on same line */ 76 if (ps.p_stack[ps.tos] != decl) { /* only put one declaration 77 * onto stack */ 78 break_comma = true; /* while in declaration, newline should be 79 * forced after comma */ 80 ps.p_stack[++ps.tos] = decl; 81 ps.il[ps.tos] = ps.i_l_follow; 82 83 if (ps.ljust_decl) {/* only do if we want left justified 84 * declarations */ 85 ps.ind_level = 0; 86 for (i = ps.tos - 1; i > 0; --i) 87 if (ps.p_stack[i] == decl) 88 ++ps.ind_level; /* indentation is number of 89 * declaration levels deep we are */ 90 ps.i_l_follow = ps.ind_level; 91 } 92 } 93 break; 94 95 case ifstmt: /* scanned if (...) */ 96 if (ps.p_stack[ps.tos] == elsehead && ps.else_if) /* "else if ..." */ 97 ps.i_l_follow = ps.il[ps.tos]; 98 /* the rest is the same as for dolit and forstmt */ 99 case dolit: /* 'do' */ 100 case forstmt: /* for (...) */ 101 ps.p_stack[++ps.tos] = tk; 102 ps.il[ps.tos] = ps.ind_level = ps.i_l_follow; 103 ++ps.i_l_follow; /* subsequent statements should be indented 1 */ 104 ps.search_brace = btype_2; 105 break; 106 107 case lbrace: /* scanned { */ 108 break_comma = false; /* don't break comma in an initial list */ 109 if (ps.p_stack[ps.tos] == stmt || ps.p_stack[ps.tos] == decl 110 || ps.p_stack[ps.tos] == stmtl) 111 ++ps.i_l_follow; /* it is a random, isolated stmt group or a 112 * declaration */ 113 else { 114 if (s_code == e_code) { 115 /* 116 * only do this if there is nothing on the line 117 */ 118 --ps.ind_level; 119 /* 120 * it is a group as part of a while, for, etc. 121 */ 122 if (ps.p_stack[ps.tos] == swstmt && ps.case_indent >= 1) 123 --ps.ind_level; 124 /* 125 * for a switch, brace should be two levels out from the code 126 */ 127 } 128 } 129 130 ps.p_stack[++ps.tos] = lbrace; 131 ps.il[ps.tos] = ps.ind_level; 132 ps.p_stack[++ps.tos] = stmt; 133 /* allow null stmt between braces */ 134 ps.il[ps.tos] = ps.i_l_follow; 135 break; 136 137 case whilestmt: /* scanned while (...) */ 138 if (ps.p_stack[ps.tos] == dohead) { 139 /* it is matched with do stmt */ 140 ps.ind_level = ps.i_l_follow = ps.il[ps.tos]; 141 ps.p_stack[++ps.tos] = whilestmt; 142 ps.il[ps.tos] = ps.ind_level = ps.i_l_follow; 143 } 144 else { /* it is a while loop */ 145 ps.p_stack[++ps.tos] = whilestmt; 146 ps.il[ps.tos] = ps.i_l_follow; 147 ++ps.i_l_follow; 148 ps.search_brace = btype_2; 149 } 150 151 break; 152 153 case elselit: /* scanned an else */ 154 155 if (ps.p_stack[ps.tos] != ifhead) 156 diag2(1, "Unmatched 'else'"); 157 else { 158 ps.ind_level = ps.il[ps.tos]; /* indentation for else should 159 * be same as for if */ 160 ps.i_l_follow = ps.ind_level + 1; /* everything following should 161 * be in 1 level */ 162 ps.p_stack[ps.tos] = elsehead; 163 /* remember if with else */ 164 ps.search_brace = btype_2 | ps.else_if; 165 } 166 break; 167 168 case rbrace: /* scanned a } */ 169 /* stack should have <lbrace> <stmt> or <lbrace> <stmtl> */ 170 if (ps.p_stack[ps.tos - 1] == lbrace) { 171 ps.ind_level = ps.i_l_follow = ps.il[--ps.tos]; 172 ps.p_stack[ps.tos] = stmt; 173 } 174 else 175 diag2(1, "Statement nesting error"); 176 break; 177 178 case swstmt: /* had switch (...) */ 179 ps.p_stack[++ps.tos] = swstmt; 180 ps.cstk[ps.tos] = case_ind; 181 /* save current case indent level */ 182 ps.il[ps.tos] = ps.i_l_follow; 183 case_ind = ps.i_l_follow + ps.case_indent; /* cases should be one 184 * level down from 185 * switch */ 186 ps.i_l_follow += ps.case_indent + 1; /* statements should be two 187 * levels in */ 188 ps.search_brace = btype_2; 189 break; 190 191 case semicolon: /* this indicates a simple stmt */ 192 break_comma = false; /* turn off flag to break after commas in a 193 * declaration */ 194 ps.p_stack[++ps.tos] = stmt; 195 ps.il[ps.tos] = ps.ind_level; 196 break; 197 198 default: /* this is an error */ 199 diag2(1, "Unknown code to parser"); 200 return; 201 202 203 } /* end of switch */ 204 205 if (ps.tos >= STACKSIZE) 206 errx(1, "Parser stack overflow"); 207 208 reduce(); /* see if any reduction can be done */ 209 210 #ifdef debug 211 for (i = 1; i <= ps.tos; ++i) 212 printf("(%d %d)", ps.p_stack[i], ps.il[i]); 213 printf("\n"); 214 #endif 215 216 return; 217 } 218 219 /* 220 * NAME: reduce 221 * 222 * FUNCTION: Implements the reduce part of the parsing algorithm 223 * 224 * ALGORITHM: The following reductions are done. Reductions are repeated 225 * until no more are possible. 226 * 227 * Old TOS New TOS 228 * <stmt> <stmt> <stmtl> 229 * <stmtl> <stmt> <stmtl> 230 * do <stmt> "dostmt" 231 * if <stmt> "ifstmt" 232 * switch <stmt> <stmt> 233 * decl <stmt> <stmt> 234 * "ifelse" <stmt> <stmt> 235 * for <stmt> <stmt> 236 * while <stmt> <stmt> 237 * "dostmt" while <stmt> 238 * 239 * On each reduction, ps.i_l_follow (the indentation for the following line) 240 * is set to the indentation level associated with the old TOS. 241 * 242 * PARAMETERS: None 243 * 244 * RETURNS: Nothing 245 * 246 * GLOBALS: ps.cstk ps.i_l_follow = ps.il ps.p_stack = ps.tos = 247 * 248 * CALLS: None 249 * 250 * CALLED BY: parse 251 * 252 * HISTORY: initial coding November 1976 D A Willcox of CAC 253 * 254 */ 255 /*----------------------------------------------*\ 256 | REDUCTION PHASE | 257 \*----------------------------------------------*/ 258 static void 259 reduce(void) 260 { 261 int i; 262 263 for (;;) { /* keep looping until there is nothing left to 264 * reduce */ 265 266 switch (ps.p_stack[ps.tos]) { 267 268 case stmt: 269 switch (ps.p_stack[ps.tos - 1]) { 270 271 case stmt: 272 case stmtl: 273 /* stmtl stmt or stmt stmt */ 274 ps.p_stack[--ps.tos] = stmtl; 275 break; 276 277 case dolit: /* <do> <stmt> */ 278 ps.p_stack[--ps.tos] = dohead; 279 ps.i_l_follow = ps.il[ps.tos]; 280 break; 281 282 case ifstmt: 283 /* <if> <stmt> */ 284 ps.p_stack[--ps.tos] = ifhead; 285 for (i = ps.tos - 1; 286 ( 287 ps.p_stack[i] != stmt 288 && 289 ps.p_stack[i] != stmtl 290 && 291 ps.p_stack[i] != lbrace 292 ); 293 --i); 294 ps.i_l_follow = ps.il[i]; 295 /* 296 * for the time being, we will assume that there is no else on 297 * this if, and set the indentation level accordingly. If an 298 * else is scanned, it will be fixed up later 299 */ 300 break; 301 302 case swstmt: 303 /* <switch> <stmt> */ 304 case_ind = ps.cstk[ps.tos - 1]; 305 /* FALLTHROUGH */ 306 case decl: /* finish of a declaration */ 307 case elsehead: 308 /* <<if> <stmt> else> <stmt> */ 309 case forstmt: 310 /* <for> <stmt> */ 311 case whilestmt: 312 /* <while> <stmt> */ 313 ps.p_stack[--ps.tos] = stmt; 314 ps.i_l_follow = ps.il[ps.tos]; 315 break; 316 317 default: /* <anything else> <stmt> */ 318 return; 319 320 } /* end of section for <stmt> on top of stack */ 321 break; 322 323 case whilestmt: /* while (...) on top */ 324 if (ps.p_stack[ps.tos - 1] == dohead) { 325 /* it is termination of a do while */ 326 ps.tos -= 2; 327 break; 328 } 329 else 330 return; 331 332 default: /* anything else on top */ 333 return; 334 335 } 336 } 337 } 338