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