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 case dolit: /* 'do' */ 99 case forstmt: /* for (...) */ 100 ps.p_stack[++ps.tos] = tk; 101 ps.il[ps.tos] = ps.ind_level = ps.i_l_follow; 102 ++ps.i_l_follow; /* subsequent statements should be indented 1 */ 103 ps.search_brace = btype_2; 104 break; 105 106 case lbrace: /* scanned { */ 107 break_comma = false; /* don't break comma in an initial list */ 108 if (ps.p_stack[ps.tos] == stmt || ps.p_stack[ps.tos] == decl 109 || ps.p_stack[ps.tos] == stmtl) 110 ++ps.i_l_follow; /* it is a random, isolated stmt group or a 111 * declaration */ 112 else { 113 if (s_code == e_code) { 114 /* 115 * only do this if there is nothing on the line 116 */ 117 --ps.ind_level; 118 /* 119 * it is a group as part of a while, for, etc. 120 */ 121 if (ps.p_stack[ps.tos] == swstmt && ps.case_indent >= 1) 122 --ps.ind_level; 123 /* 124 * for a switch, brace should be two levels out from the code 125 */ 126 } 127 } 128 129 ps.p_stack[++ps.tos] = lbrace; 130 ps.il[ps.tos] = ps.ind_level; 131 ps.p_stack[++ps.tos] = stmt; 132 /* allow null stmt between braces */ 133 ps.il[ps.tos] = ps.i_l_follow; 134 break; 135 136 case whilestmt: /* scanned while (...) */ 137 if (ps.p_stack[ps.tos] == dohead) { 138 /* it is matched with do stmt */ 139 ps.ind_level = ps.i_l_follow = ps.il[ps.tos]; 140 ps.p_stack[++ps.tos] = whilestmt; 141 ps.il[ps.tos] = ps.ind_level = ps.i_l_follow; 142 } 143 else { /* it is a while loop */ 144 ps.p_stack[++ps.tos] = whilestmt; 145 ps.il[ps.tos] = ps.i_l_follow; 146 ++ps.i_l_follow; 147 ps.search_brace = btype_2; 148 } 149 150 break; 151 152 case elselit: /* scanned an else */ 153 154 if (ps.p_stack[ps.tos] != ifhead) 155 diag2(1, "Unmatched 'else'"); 156 else { 157 ps.ind_level = ps.il[ps.tos]; /* indentation for else should 158 * be same as for if */ 159 ps.i_l_follow = ps.ind_level + 1; /* everything following should 160 * be in 1 level */ 161 ps.p_stack[ps.tos] = elsehead; 162 /* remember if with else */ 163 ps.search_brace = btype_2 | ps.else_if; 164 } 165 break; 166 167 case rbrace: /* scanned a } */ 168 /* stack should have <lbrace> <stmt> or <lbrace> <stmtl> */ 169 if (ps.p_stack[ps.tos - 1] == lbrace) { 170 ps.ind_level = ps.i_l_follow = ps.il[--ps.tos]; 171 ps.p_stack[ps.tos] = stmt; 172 } 173 else 174 diag2(1, "Statement nesting error"); 175 break; 176 177 case swstmt: /* had switch (...) */ 178 ps.p_stack[++ps.tos] = swstmt; 179 ps.cstk[ps.tos] = case_ind; 180 /* save current case indent level */ 181 ps.il[ps.tos] = ps.i_l_follow; 182 case_ind = ps.i_l_follow + ps.case_indent; /* cases should be one 183 * level down from 184 * switch */ 185 ps.i_l_follow += ps.case_indent + 1; /* statements should be two 186 * levels in */ 187 ps.search_brace = btype_2; 188 break; 189 190 case semicolon: /* this indicates a simple stmt */ 191 break_comma = false; /* turn off flag to break after commas in a 192 * declaration */ 193 ps.p_stack[++ps.tos] = stmt; 194 ps.il[ps.tos] = ps.ind_level; 195 break; 196 197 default: /* this is an error */ 198 diag2(1, "Unknown code to parser"); 199 return; 200 201 202 } /* end of switch */ 203 204 if (ps.tos >= STACKSIZE) 205 errx(1, "Parser stack overflow"); 206 207 reduce(); /* see if any reduction can be done */ 208 209 #ifdef debug 210 for (i = 1; i <= ps.tos; ++i) 211 printf("(%d %d)", ps.p_stack[i], ps.il[i]); 212 printf("\n"); 213 #endif 214 215 return; 216 } 217 218 /* 219 * NAME: reduce 220 * 221 * FUNCTION: Implements the reduce part of the parsing algorithm 222 * 223 * ALGORITHM: The following reductions are done. Reductions are repeated 224 * until no more are possible. 225 * 226 * Old TOS New TOS 227 * <stmt> <stmt> <stmtl> 228 * <stmtl> <stmt> <stmtl> 229 * do <stmt> "dostmt" 230 * if <stmt> "ifstmt" 231 * switch <stmt> <stmt> 232 * decl <stmt> <stmt> 233 * "ifelse" <stmt> <stmt> 234 * for <stmt> <stmt> 235 * while <stmt> <stmt> 236 * "dostmt" while <stmt> 237 * 238 * On each reduction, ps.i_l_follow (the indentation for the following line) 239 * is set to the indentation level associated with the old TOS. 240 * 241 * PARAMETERS: None 242 * 243 * RETURNS: Nothing 244 * 245 * GLOBALS: ps.cstk ps.i_l_follow = ps.il ps.p_stack = ps.tos = 246 * 247 * CALLS: None 248 * 249 * CALLED BY: parse 250 * 251 * HISTORY: initial coding November 1976 D A Willcox of CAC 252 * 253 */ 254 /*----------------------------------------------*\ 255 | REDUCTION PHASE | 256 \*----------------------------------------------*/ 257 static void 258 reduce(void) 259 { 260 int i; 261 262 for (;;) { /* keep looping until there is nothing left to 263 * reduce */ 264 265 switch (ps.p_stack[ps.tos]) { 266 267 case stmt: 268 switch (ps.p_stack[ps.tos - 1]) { 269 270 case stmt: 271 case stmtl: 272 /* stmtl stmt or stmt stmt */ 273 ps.p_stack[--ps.tos] = stmtl; 274 break; 275 276 case dolit: /* <do> <stmt> */ 277 ps.p_stack[--ps.tos] = dohead; 278 ps.i_l_follow = ps.il[ps.tos]; 279 break; 280 281 case ifstmt: 282 /* <if> <stmt> */ 283 ps.p_stack[--ps.tos] = ifhead; 284 for (i = ps.tos - 1; 285 ( 286 ps.p_stack[i] != stmt 287 && 288 ps.p_stack[i] != stmtl 289 && 290 ps.p_stack[i] != lbrace 291 ); 292 --i); 293 ps.i_l_follow = ps.il[i]; 294 /* 295 * for the time being, we will assume that there is no else on 296 * this if, and set the indentation level accordingly. If an 297 * else is scanned, it will be fixed up later 298 */ 299 break; 300 301 case swstmt: 302 /* <switch> <stmt> */ 303 case_ind = ps.cstk[ps.tos - 1]; 304 305 case decl: /* finish of a declaration */ 306 case elsehead: 307 /* <<if> <stmt> else> <stmt> */ 308 case forstmt: 309 /* <for> <stmt> */ 310 case whilestmt: 311 /* <while> <stmt> */ 312 ps.p_stack[--ps.tos] = stmt; 313 ps.i_l_follow = ps.il[ps.tos]; 314 break; 315 316 default: /* <anything else> <stmt> */ 317 return; 318 319 } /* end of section for <stmt> on top of stack */ 320 break; 321 322 case whilestmt: /* while (...) on top */ 323 if (ps.p_stack[ps.tos - 1] == dohead) { 324 /* it is termination of a do while */ 325 ps.tos -= 2; 326 break; 327 } 328 else 329 return; 330 331 default: /* anything else on top */ 332 return; 333 334 } 335 } 336 } 337