2 * SPDX-License-Identifier: BSD-4-Clause
4 * Copyright (c) 1985 Sun Microsystems, Inc.
5 * Copyright (c) 1980, 1993
6 * The Regents of the University of California. All rights reserved.
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10 * modification, are permitted provided that the following conditions
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13 * notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in the
16 * documentation and/or other materials provided with the distribution.
17 * 3. All advertising materials mentioning features or use of this software
18 * must display the following acknowledgement:
19 * This product includes software developed by the University of
20 * California, Berkeley and its contributors.
21 * 4. Neither the name of the University nor the names of its contributors
22 * may be used to endorse or promote products derived from this software
23 * without specific prior written permission.
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40 static char sccsid[] = "@(#)parse.c 8.1 (Berkeley) 6/6/93";
44 #include <sys/cdefs.h>
45 __FBSDID("$FreeBSD$");
49 #include "indent_globs.h"
50 #include "indent_codes.h"
57 static void reduce(void);
60 parse(int tk) /* tk: the code for the construct scanned */
65 printf("%2d - %s\n", tk, token);
68 while (ps.p_stack[ps.tos] == ifhead && tk != elselit) {
69 /* true if we have an if without an else */
70 ps.p_stack[ps.tos] = stmt; /* apply the if(..) stmt ::= stmt
72 reduce(); /* see if this allows any reduction */
76 switch (tk) { /* go on and figure out what to do with the
79 case decl: /* scanned a declaration word */
80 ps.search_brace = opt.btype_2;
81 /* indicate that following brace should be on same line */
82 if (ps.p_stack[ps.tos] != decl) { /* only put one declaration
84 break_comma = true; /* while in declaration, newline should be
85 * forced after comma */
86 ps.p_stack[++ps.tos] = decl;
87 ps.il[ps.tos] = ps.i_l_follow;
89 if (opt.ljust_decl) {/* only do if we want left justified
92 for (i = ps.tos - 1; i > 0; --i)
93 if (ps.p_stack[i] == decl)
94 ++ps.ind_level; /* indentation is number of
95 * declaration levels deep we are */
96 ps.i_l_follow = ps.ind_level;
101 case ifstmt: /* scanned if (...) */
102 if (ps.p_stack[ps.tos] == elsehead && opt.else_if) /* "else if ..." */
104 * Note that the stack pointer here is decremented, effectively
105 * reducing "else if" to "if". This saves a lot of stack space
106 * in case of a long "if-else-if ... else-if" sequence.
108 ps.i_l_follow = ps.il[ps.tos--];
109 /* the rest is the same as for dolit and forstmt */
110 case dolit: /* 'do' */
111 case forstmt: /* for (...) */
112 ps.p_stack[++ps.tos] = tk;
113 ps.il[ps.tos] = ps.ind_level = ps.i_l_follow;
114 ++ps.i_l_follow; /* subsequent statements should be indented 1 */
115 ps.search_brace = opt.btype_2;
118 case lbrace: /* scanned { */
119 break_comma = false; /* don't break comma in an initial list */
120 if (ps.p_stack[ps.tos] == stmt || ps.p_stack[ps.tos] == decl
121 || ps.p_stack[ps.tos] == stmtl)
122 ++ps.i_l_follow; /* it is a random, isolated stmt group or a
125 if (s_code == e_code) {
127 * only do this if there is nothing on the line
131 * it is a group as part of a while, for, etc.
133 if (ps.p_stack[ps.tos] == swstmt && opt.case_indent >= 1)
136 * for a switch, brace should be two levels out from the code
141 ps.p_stack[++ps.tos] = lbrace;
142 ps.il[ps.tos] = ps.ind_level;
143 ps.p_stack[++ps.tos] = stmt;
144 /* allow null stmt between braces */
145 ps.il[ps.tos] = ps.i_l_follow;
148 case whilestmt: /* scanned while (...) */
149 if (ps.p_stack[ps.tos] == dohead) {
150 /* it is matched with do stmt */
151 ps.ind_level = ps.i_l_follow = ps.il[ps.tos];
152 ps.p_stack[++ps.tos] = whilestmt;
153 ps.il[ps.tos] = ps.ind_level = ps.i_l_follow;
155 else { /* it is a while loop */
156 ps.p_stack[++ps.tos] = whilestmt;
157 ps.il[ps.tos] = ps.i_l_follow;
159 ps.search_brace = opt.btype_2;
164 case elselit: /* scanned an else */
166 if (ps.p_stack[ps.tos] != ifhead)
167 diag2(1, "Unmatched 'else'");
169 ps.ind_level = ps.il[ps.tos]; /* indentation for else should
170 * be same as for if */
171 ps.i_l_follow = ps.ind_level + 1; /* everything following should
173 ps.p_stack[ps.tos] = elsehead;
174 /* remember if with else */
175 ps.search_brace = opt.btype_2 | opt.else_if;
179 case rbrace: /* scanned a } */
180 /* stack should have <lbrace> <stmt> or <lbrace> <stmtl> */
181 if (ps.tos > 0 && ps.p_stack[ps.tos - 1] == lbrace) {
182 ps.ind_level = ps.i_l_follow = ps.il[--ps.tos];
183 ps.p_stack[ps.tos] = stmt;
186 diag2(1, "Statement nesting error");
189 case swstmt: /* had switch (...) */
190 ps.p_stack[++ps.tos] = swstmt;
191 ps.cstk[ps.tos] = case_ind;
192 /* save current case indent level */
193 ps.il[ps.tos] = ps.i_l_follow;
194 case_ind = ps.i_l_follow + opt.case_indent; /* cases should be one
197 ps.i_l_follow += opt.case_indent + 1; /* statements should be two
199 ps.search_brace = opt.btype_2;
202 case semicolon: /* this indicates a simple stmt */
203 break_comma = false; /* turn off flag to break after commas in a
205 ps.p_stack[++ps.tos] = stmt;
206 ps.il[ps.tos] = ps.ind_level;
209 default: /* this is an error */
210 diag2(1, "Unknown code to parser");
214 } /* end of switch */
216 if (ps.tos >= STACKSIZE - 1)
217 errx(1, "Parser stack overflow");
219 reduce(); /* see if any reduction can be done */
222 for (i = 1; i <= ps.tos; ++i)
223 printf("(%d %d)", ps.p_stack[i], ps.il[i]);
233 * FUNCTION: Implements the reduce part of the parsing algorithm
235 * ALGORITHM: The following reductions are done. Reductions are repeated
236 * until no more are possible.
239 * <stmt> <stmt> <stmtl>
240 * <stmtl> <stmt> <stmtl>
243 * switch <stmt> <stmt>
245 * "ifelse" <stmt> <stmt>
247 * while <stmt> <stmt>
248 * "dostmt" while <stmt>
250 * On each reduction, ps.i_l_follow (the indentation for the following line)
251 * is set to the indentation level associated with the old TOS.
257 * GLOBALS: ps.cstk ps.i_l_follow = ps.il ps.p_stack = ps.tos =
263 * HISTORY: initial coding November 1976 D A Willcox of CAC
266 /*----------------------------------------------*\
268 \*----------------------------------------------*/
274 for (;;) { /* keep looping until there is nothing left to
277 switch (ps.p_stack[ps.tos]) {
280 switch (ps.p_stack[ps.tos - 1]) {
284 /* stmtl stmt or stmt stmt */
285 ps.p_stack[--ps.tos] = stmtl;
288 case dolit: /* <do> <stmt> */
289 ps.p_stack[--ps.tos] = dohead;
290 ps.i_l_follow = ps.il[ps.tos];
295 ps.p_stack[--ps.tos] = ifhead;
298 ps.p_stack[i] != stmt
300 ps.p_stack[i] != stmtl
302 ps.p_stack[i] != lbrace
305 ps.i_l_follow = ps.il[i];
307 * for the time being, we will assume that there is no else on
308 * this if, and set the indentation level accordingly. If an
309 * else is scanned, it will be fixed up later
314 /* <switch> <stmt> */
315 case_ind = ps.cstk[ps.tos - 1];
317 case decl: /* finish of a declaration */
319 /* <<if> <stmt> else> <stmt> */
324 ps.p_stack[--ps.tos] = stmt;
325 ps.i_l_follow = ps.il[ps.tos];
328 default: /* <anything else> <stmt> */
331 } /* end of section for <stmt> on top of stack */
334 case whilestmt: /* while (...) on top */
335 if (ps.p_stack[ps.tos - 1] == dohead) {
336 /* it is termination of a do while */
343 default: /* anything else on top */