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
37 static char sccsid[] = "@(#)parse.c 8.1 (Berkeley) 6/6/93";
38 static const char rcsid[] =
44 #include "indent_globs.h"
45 #include "indent_codes.h"
48 static void reduce(void);
51 parse(int tk) /* tk: the code for the construct scanned */
56 printf("%2d - %s\n", tk, token);
59 while (ps.p_stack[ps.tos] == ifhead && tk != elselit) {
60 /* true if we have an if without an else */
61 ps.p_stack[ps.tos] = stmt; /* apply the if(..) stmt ::= stmt
63 reduce(); /* see if this allows any reduction */
67 switch (tk) { /* go on and figure out what to do with the
70 case decl: /* scanned a declaration word */
71 ps.search_brace = btype_2;
72 /* indicate that following brace should be on same line */
73 if (ps.p_stack[ps.tos] != decl) { /* only put one declaration
75 break_comma = true; /* while in declaration, newline should be
76 * forced after comma */
77 ps.p_stack[++ps.tos] = decl;
78 ps.il[ps.tos] = ps.i_l_follow;
80 if (ps.ljust_decl) {/* only do if we want left justified
83 for (i = ps.tos - 1; i > 0; --i)
84 if (ps.p_stack[i] == decl)
85 ++ps.ind_level; /* indentation is number of
86 * declaration levels deep we are */
87 ps.i_l_follow = ps.ind_level;
92 case ifstmt: /* scanned if (...) */
93 if (ps.p_stack[ps.tos] == elsehead && ps.else_if) /* "else if ..." */
94 ps.i_l_follow = ps.il[ps.tos];
95 case dolit: /* 'do' */
96 case forstmt: /* for (...) */
97 ps.p_stack[++ps.tos] = tk;
98 ps.il[ps.tos] = ps.ind_level = ps.i_l_follow;
99 ++ps.i_l_follow; /* subsequent statements should be indented 1 */
100 ps.search_brace = btype_2;
103 case lbrace: /* scanned { */
104 break_comma = false; /* don't break comma in an initial list */
105 if (ps.p_stack[ps.tos] == stmt || ps.p_stack[ps.tos] == decl
106 || ps.p_stack[ps.tos] == stmtl)
107 ++ps.i_l_follow; /* it is a random, isolated stmt group or a
110 if (s_code == e_code) {
112 * only do this if there is nothing on the line
116 * it is a group as part of a while, for, etc.
118 if (ps.p_stack[ps.tos] == swstmt && ps.case_indent >= 1)
121 * for a switch, brace should be two levels out from the code
126 ps.p_stack[++ps.tos] = lbrace;
127 ps.il[ps.tos] = ps.ind_level;
128 ps.p_stack[++ps.tos] = stmt;
129 /* allow null stmt between braces */
130 ps.il[ps.tos] = ps.i_l_follow;
133 case whilestmt: /* scanned while (...) */
134 if (ps.p_stack[ps.tos] == dohead) {
135 /* it is matched with do stmt */
136 ps.ind_level = ps.i_l_follow = ps.il[ps.tos];
137 ps.p_stack[++ps.tos] = whilestmt;
138 ps.il[ps.tos] = ps.ind_level = ps.i_l_follow;
140 else { /* it is a while loop */
141 ps.p_stack[++ps.tos] = whilestmt;
142 ps.il[ps.tos] = ps.i_l_follow;
144 ps.search_brace = btype_2;
149 case elselit: /* scanned an else */
151 if (ps.p_stack[ps.tos] != ifhead)
152 diag2(1, "Unmatched 'else'");
154 ps.ind_level = ps.il[ps.tos]; /* indentation for else should
155 * be same as for if */
156 ps.i_l_follow = ps.ind_level + 1; /* everything following should
158 ps.p_stack[ps.tos] = elsehead;
159 /* remember if with else */
160 ps.search_brace = btype_2 | ps.else_if;
164 case rbrace: /* scanned a } */
165 /* stack should have <lbrace> <stmt> or <lbrace> <stmtl> */
166 if (ps.p_stack[ps.tos - 1] == lbrace) {
167 ps.ind_level = ps.i_l_follow = ps.il[--ps.tos];
168 ps.p_stack[ps.tos] = stmt;
171 diag2(1, "Stmt nesting error.");
174 case swstmt: /* had switch (...) */
175 ps.p_stack[++ps.tos] = swstmt;
176 ps.cstk[ps.tos] = case_ind;
177 /* save current case indent level */
178 ps.il[ps.tos] = ps.i_l_follow;
179 case_ind = ps.i_l_follow + ps.case_indent; /* cases should be one
182 ps.i_l_follow += ps.case_indent + 1; /* statements should be two
184 ps.search_brace = btype_2;
187 case semicolon: /* this indicates a simple stmt */
188 break_comma = false; /* turn off flag to break after commas in a
190 ps.p_stack[++ps.tos] = stmt;
191 ps.il[ps.tos] = ps.ind_level;
194 default: /* this is an error */
195 diag2(1, "Unknown code to parser");
199 } /* end of switch */
201 reduce(); /* see if any reduction can be done */
204 for (i = 1; i <= ps.tos; ++i)
205 printf("(%d %d)", ps.p_stack[i], ps.il[i]);
215 * FUNCTION: Implements the reduce part of the parsing algorithm
217 * ALGORITHM: The following reductions are done. Reductions are repeated
218 * until no more are possible.
221 * <stmt> <stmt> <stmtl>
222 * <stmtl> <stmt> <stmtl>
225 * switch <stmt> <stmt>
227 * "ifelse" <stmt> <stmt>
229 * while <stmt> <stmt>
230 * "dostmt" while <stmt>
232 * On each reduction, ps.i_l_follow (the indentation for the following line)
233 * is set to the indentation level associated with the old TOS.
239 * GLOBALS: ps.cstk ps.i_l_follow = ps.il ps.p_stack = ps.tos =
245 * HISTORY: initial coding November 1976 D A Willcox of CAC
248 /*----------------------------------------------*\
250 \*----------------------------------------------*/
256 for (;;) { /* keep looping until there is nothing left to
259 switch (ps.p_stack[ps.tos]) {
262 switch (ps.p_stack[ps.tos - 1]) {
266 /* stmtl stmt or stmt stmt */
267 ps.p_stack[--ps.tos] = stmtl;
270 case dolit: /* <do> <stmt> */
271 ps.p_stack[--ps.tos] = dohead;
272 ps.i_l_follow = ps.il[ps.tos];
277 ps.p_stack[--ps.tos] = ifhead;
280 ps.p_stack[i] != stmt
282 ps.p_stack[i] != stmtl
284 ps.p_stack[i] != lbrace
287 ps.i_l_follow = ps.il[i];
289 * for the time being, we will assume that there is no else on
290 * this if, and set the indentation level accordingly. If an
291 * else is scanned, it will be fixed up later
296 /* <switch> <stmt> */
297 case_ind = ps.cstk[ps.tos - 1];
299 case decl: /* finish of a declaration */
301 /* <<if> <stmt> else> <stmt> */
306 ps.p_stack[--ps.tos] = stmt;
307 ps.i_l_follow = ps.il[ps.tos];
310 default: /* <anything else> <stmt> */
313 } /* end of section for <stmt> on top of stack */
316 case whilestmt: /* while (...) on top */
317 if (ps.p_stack[ps.tos - 1] == dohead) {
318 /* it is termination of a do while */
325 default: /* anything else on top */