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