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. Neither the name of the University nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 * 31 * @(#)parse.c 8.1 (Berkeley) 6/6/93 32 * $FreeBSD: src/usr.bin/indent/parse.c,v 1.10 2003/06/15 09:28:17 charnier Exp $ 33 */ 34 35 #include <stdio.h> 36 #include "indent_globs.h" 37 #include "indent_codes.h" 38 #include "indent.h" 39 40 static void reduce(void); 41 42 void 43 parse(int tk) /* tk: the code for the construct scanned */ 44 { 45 int i; 46 47 #ifdef debug 48 printf("%2d - %s\n", tk, token); 49 #endif 50 51 while (ps.p_stack[ps.tos] == ifhead && tk != elselit) { 52 /* true if we have an if without an else */ 53 ps.p_stack[ps.tos] = stmt; /* apply the if(..) stmt ::= stmt 54 * reduction */ 55 reduce(); /* see if this allows any reduction */ 56 } 57 58 59 switch (tk) { /* go on and figure out what to do with the 60 * input */ 61 62 case decl: /* scanned a declaration word */ 63 ps.search_brace = btype_2; 64 /* indicate that following brace should be on same line */ 65 if (ps.p_stack[ps.tos] != decl) { /* only put one declaration 66 * onto stack */ 67 break_comma = true; /* while in declaration, newline should be 68 * forced after comma */ 69 ps.p_stack[++ps.tos] = decl; 70 ps.il[ps.tos] = ps.i_l_follow; 71 72 if (ps.ljust_decl) {/* only do if we want left justified 73 * declarations */ 74 ps.ind_level = 0; 75 for (i = ps.tos - 1; i > 0; --i) 76 if (ps.p_stack[i] == decl) 77 ++ps.ind_level; /* indentation is number of 78 * declaration levels deep we are */ 79 ps.i_l_follow = ps.ind_level; 80 } 81 } 82 break; 83 84 case ifstmt: /* scanned if (...) */ 85 if (ps.p_stack[ps.tos] == elsehead && ps.else_if) /* "else if ..." */ 86 ps.i_l_follow = ps.il[ps.tos]; 87 /* FALLTHROUGH */ 88 case dolit: /* 'do' */ 89 case forstmt: /* for (...) */ 90 ps.p_stack[++ps.tos] = tk; 91 ps.il[ps.tos] = ps.ind_level = ps.i_l_follow; 92 ++ps.i_l_follow; /* subsequent statements should be indented 1 */ 93 ps.search_brace = btype_2; 94 break; 95 96 case lbrace: /* scanned { */ 97 break_comma = false; /* don't break comma in an initial list */ 98 if (ps.p_stack[ps.tos] == stmt || ps.p_stack[ps.tos] == decl 99 || ps.p_stack[ps.tos] == stmtl) 100 ++ps.i_l_follow; /* it is a random, isolated stmt group or a 101 * declaration */ 102 else { 103 if (s_code == e_code) { 104 /* 105 * only do this if there is nothing on the line 106 */ 107 --ps.ind_level; 108 /* 109 * it is a group as part of a while, for, etc. 110 */ 111 if (ps.p_stack[ps.tos] == swstmt && ps.case_indent >= 1) 112 --ps.ind_level; 113 /* 114 * for a switch, brace should be two levels out from the code 115 */ 116 } 117 } 118 119 ps.p_stack[++ps.tos] = lbrace; 120 ps.il[ps.tos] = ps.ind_level; 121 ps.p_stack[++ps.tos] = stmt; 122 /* allow null stmt between braces */ 123 ps.il[ps.tos] = ps.i_l_follow; 124 break; 125 126 case whilestmt: /* scanned while (...) */ 127 if (ps.p_stack[ps.tos] == dohead) { 128 /* it is matched with do stmt */ 129 ps.ind_level = ps.i_l_follow = ps.il[ps.tos]; 130 ps.p_stack[++ps.tos] = whilestmt; 131 ps.il[ps.tos] = ps.ind_level = ps.i_l_follow; 132 } 133 else { /* it is a while loop */ 134 ps.p_stack[++ps.tos] = whilestmt; 135 ps.il[ps.tos] = ps.i_l_follow; 136 ++ps.i_l_follow; 137 ps.search_brace = btype_2; 138 } 139 140 break; 141 142 case elselit: /* scanned an else */ 143 144 if (ps.p_stack[ps.tos] != ifhead) 145 diag2(1, "Unmatched 'else'"); 146 else { 147 ps.ind_level = ps.il[ps.tos]; /* indentation for else should 148 * be same as for if */ 149 ps.i_l_follow = ps.ind_level + 1; /* everything following should 150 * be in 1 level */ 151 ps.p_stack[ps.tos] = elsehead; 152 /* remember if with else */ 153 ps.search_brace = btype_2 | ps.else_if; 154 } 155 break; 156 157 case rbrace: /* scanned a } */ 158 /* stack should have <lbrace> <stmt> or <lbrace> <stmtl> */ 159 if (ps.p_stack[ps.tos - 1] == lbrace) { 160 ps.ind_level = ps.i_l_follow = ps.il[--ps.tos]; 161 ps.p_stack[ps.tos] = stmt; 162 } 163 else 164 diag2(1, "Statement nesting error"); 165 break; 166 167 case swstmt: /* had switch (...) */ 168 ps.p_stack[++ps.tos] = swstmt; 169 ps.cstk[ps.tos] = case_ind; 170 /* save current case indent level */ 171 ps.il[ps.tos] = ps.i_l_follow; 172 case_ind = ps.i_l_follow + ps.case_indent; /* cases should be one 173 * level down from 174 * switch */ 175 ps.i_l_follow += ps.case_indent + 1; /* statements should be two 176 * levels in */ 177 ps.search_brace = btype_2; 178 break; 179 180 case semicolon: /* this indicates a simple stmt */ 181 break_comma = false; /* turn off flag to break after commas in a 182 * declaration */ 183 ps.p_stack[++ps.tos] = stmt; 184 ps.il[ps.tos] = ps.ind_level; 185 break; 186 187 default: /* this is an error */ 188 diag2(1, "Unknown code to parser"); 189 return; 190 191 192 } /* end of switch */ 193 194 reduce(); /* see if any reduction can be done */ 195 196 #ifdef debug 197 for (i = 1; i <= ps.tos; ++i) 198 printf("(%d %d)", ps.p_stack[i], ps.il[i]); 199 printf("\n"); 200 #endif 201 202 return; 203 } 204 205 /* 206 * NAME: reduce 207 * 208 * FUNCTION: Implements the reduce part of the parsing algorithm 209 * 210 * ALGORITHM: The following reductions are done. Reductions are repeated 211 * until no more are possible. 212 * 213 * Old TOS New TOS 214 * <stmt> <stmt> <stmtl> 215 * <stmtl> <stmt> <stmtl> 216 * do <stmt> "dostmt" 217 * if <stmt> "ifstmt" 218 * switch <stmt> <stmt> 219 * decl <stmt> <stmt> 220 * "ifelse" <stmt> <stmt> 221 * for <stmt> <stmt> 222 * while <stmt> <stmt> 223 * "dostmt" while <stmt> 224 * 225 * On each reduction, ps.i_l_follow (the indentation for the following line) 226 * is set to the indentation level associated with the old TOS. 227 * 228 * PARAMETERS: None 229 * 230 * RETURNS: Nothing 231 * 232 * GLOBALS: ps.cstk ps.i_l_follow = ps.il ps.p_stack = ps.tos = 233 * 234 * CALLS: None 235 * 236 * CALLED BY: parse 237 * 238 * HISTORY: initial coding November 1976 D A Willcox of CAC 239 * 240 */ 241 /*----------------------------------------------*\ 242 | REDUCTION PHASE | 243 \*----------------------------------------------*/ 244 static void 245 reduce(void) 246 { 247 int i; 248 249 for (;;) { /* keep looping until there is nothing left to 250 * reduce */ 251 252 switch (ps.p_stack[ps.tos]) { 253 254 case stmt: 255 switch (ps.p_stack[ps.tos - 1]) { 256 257 case stmt: 258 case stmtl: 259 /* stmtl stmt or stmt stmt */ 260 ps.p_stack[--ps.tos] = stmtl; 261 break; 262 263 case dolit: /* <do> <stmt> */ 264 ps.p_stack[--ps.tos] = dohead; 265 ps.i_l_follow = ps.il[ps.tos]; 266 break; 267 268 case ifstmt: 269 /* <if> <stmt> */ 270 ps.p_stack[--ps.tos] = ifhead; 271 for (i = ps.tos - 1; 272 ( 273 ps.p_stack[i] != stmt 274 && 275 ps.p_stack[i] != stmtl 276 && 277 ps.p_stack[i] != lbrace 278 ); 279 --i); 280 ps.i_l_follow = ps.il[i]; 281 /* 282 * for the time being, we will assume that there is no else on 283 * this if, and set the indentation level accordingly. If an 284 * else is scanned, it will be fixed up later 285 */ 286 break; 287 288 case swstmt: 289 /* <switch> <stmt> */ 290 case_ind = ps.cstk[ps.tos - 1]; 291 /* FALLTHROUGH */ 292 case decl: /* finish of a declaration */ 293 case elsehead: 294 /* <<if> <stmt> else> <stmt> */ 295 case forstmt: 296 /* <for> <stmt> */ 297 case whilestmt: 298 /* <while> <stmt> */ 299 ps.p_stack[--ps.tos] = stmt; 300 ps.i_l_follow = ps.il[ps.tos]; 301 break; 302 303 default: /* <anything else> <stmt> */ 304 return; 305 306 } /* end of section for <stmt> on top of stack */ 307 break; 308 309 case whilestmt: /* while (...) on top */ 310 if (ps.p_stack[ps.tos - 1] == dohead) { 311 /* it is termination of a do while */ 312 ps.tos -= 2; 313 break; 314 } 315 else 316 return; 317 318 default: /* anything else on top */ 319 return; 320 321 } 322 } 323 } 324