2 * Copyright (c) 1985 Sun Microsystems, Inc.
3 * Copyright (c) 1980, 1993
4 * The Regents of the University of California. All rights reserved.
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
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.
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
38 static char sccsid[] = "@(#)parse.c 8.1 (Berkeley) 6/6/93";
42 #include <sys/cdefs.h>
43 __FBSDID("$FreeBSD$");
47 #include "indent_globs.h"
48 #include "indent_codes.h"
51 static void reduce(void);
54 parse(int tk) /* tk: the code for the construct scanned */
59 printf("%2d - %s\n", tk, token);
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
66 reduce(); /* see if this allows any reduction */
70 switch (tk) { /* go on and figure out what to do with the
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
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;
83 if (ps.ljust_decl) {/* only do if we want left justified
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;
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;
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
113 if (s_code == e_code) {
115 * only do this if there is nothing on the line
119 * it is a group as part of a while, for, etc.
121 if (ps.p_stack[ps.tos] == swstmt && ps.case_indent >= 1)
124 * for a switch, brace should be two levels out from the code
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;
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;
143 else { /* it is a while loop */
144 ps.p_stack[++ps.tos] = whilestmt;
145 ps.il[ps.tos] = ps.i_l_follow;
147 ps.search_brace = btype_2;
152 case elselit: /* scanned an else */
154 if (ps.p_stack[ps.tos] != ifhead)
155 diag2(1, "Unmatched '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
161 ps.p_stack[ps.tos] = elsehead;
162 /* remember if with else */
163 ps.search_brace = btype_2 | ps.else_if;
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;
174 diag2(1, "Statement nesting error");
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
185 ps.i_l_follow += ps.case_indent + 1; /* statements should be two
187 ps.search_brace = btype_2;
190 case semicolon: /* this indicates a simple stmt */
191 break_comma = false; /* turn off flag to break after commas in a
193 ps.p_stack[++ps.tos] = stmt;
194 ps.il[ps.tos] = ps.ind_level;
197 default: /* this is an error */
198 diag2(1, "Unknown code to parser");
202 } /* end of switch */
204 if (ps.tos >= STACKSIZE)
205 errx(1, "Parser stack overflow");
207 reduce(); /* see if any reduction can be done */
210 for (i = 1; i <= ps.tos; ++i)
211 printf("(%d %d)", ps.p_stack[i], ps.il[i]);
221 * FUNCTION: Implements the reduce part of the parsing algorithm
223 * ALGORITHM: The following reductions are done. Reductions are repeated
224 * until no more are possible.
227 * <stmt> <stmt> <stmtl>
228 * <stmtl> <stmt> <stmtl>
231 * switch <stmt> <stmt>
233 * "ifelse" <stmt> <stmt>
235 * while <stmt> <stmt>
236 * "dostmt" while <stmt>
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.
245 * GLOBALS: ps.cstk ps.i_l_follow = ps.il ps.p_stack = ps.tos =
251 * HISTORY: initial coding November 1976 D A Willcox of CAC
254 /*----------------------------------------------*\
256 \*----------------------------------------------*/
262 for (;;) { /* keep looping until there is nothing left to
265 switch (ps.p_stack[ps.tos]) {
268 switch (ps.p_stack[ps.tos - 1]) {
272 /* stmtl stmt or stmt stmt */
273 ps.p_stack[--ps.tos] = stmtl;
276 case dolit: /* <do> <stmt> */
277 ps.p_stack[--ps.tos] = dohead;
278 ps.i_l_follow = ps.il[ps.tos];
283 ps.p_stack[--ps.tos] = ifhead;
286 ps.p_stack[i] != stmt
288 ps.p_stack[i] != stmtl
290 ps.p_stack[i] != lbrace
293 ps.i_l_follow = ps.il[i];
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
302 /* <switch> <stmt> */
303 case_ind = ps.cstk[ps.tos - 1];
305 case decl: /* finish of a declaration */
307 /* <<if> <stmt> else> <stmt> */
312 ps.p_stack[--ps.tos] = stmt;
313 ps.i_l_follow = ps.il[ps.tos];
316 default: /* <anything else> <stmt> */
319 } /* end of section for <stmt> on top of stack */
322 case whilestmt: /* while (...) on top */
323 if (ps.p_stack[ps.tos - 1] == dohead) {
324 /* it is termination of a do while */
331 default: /* anything else on top */