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. Neither the name of the University nor the names of its contributors
16 * may be used to endorse or promote products derived from this software
17 * without specific prior written permission.
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * @(#)parse.c 8.1 (Berkeley) 6/6/93
32 * $FreeBSD: src/usr.bin/indent/parse.c,v 1.10 2003/06/15 09:28:17 charnier Exp $
36 #include "indent_globs.h"
37 #include "indent_codes.h"
40 static void reduce(void);
43 parse(int tk
) /* tk: the code for the construct scanned */
48 printf("%2d - %s\n", tk
, token
);
51 while (ps
.p_stack
[ps
.tos
] == ifhead
&& tk
!= elselit
) {
52 /* true if we have an if without an else */
53 ps
.p_stack
[ps
.tos
] = stmt
; /* apply the if(..) stmt ::= stmt
55 reduce(); /* see if this allows any reduction */
59 switch (tk
) { /* go on and figure out what to do with the
62 case decl
: /* scanned a declaration word */
63 ps
.search_brace
= btype_2
;
64 /* indicate that following brace should be on same line */
65 if (ps
.p_stack
[ps
.tos
] != decl
) { /* only put one declaration
67 break_comma
= true; /* while in declaration, newline should be
68 * forced after comma */
69 ps
.p_stack
[++ps
.tos
] = decl
;
70 ps
.il
[ps
.tos
] = ps
.i_l_follow
;
72 if (ps
.ljust_decl
) {/* only do if we want left justified
75 for (i
= ps
.tos
- 1; i
> 0; --i
)
76 if (ps
.p_stack
[i
] == decl
)
77 ++ps
.ind_level
; /* indentation is number of
78 * declaration levels deep we are */
79 ps
.i_l_follow
= ps
.ind_level
;
84 case ifstmt
: /* scanned if (...) */
85 if (ps
.p_stack
[ps
.tos
] == elsehead
&& ps
.else_if
) /* "else if ..." */
86 ps
.i_l_follow
= ps
.il
[ps
.tos
];
87 case dolit
: /* 'do' */
88 case forstmt
: /* for (...) */
89 ps
.p_stack
[++ps
.tos
] = tk
;
90 ps
.il
[ps
.tos
] = ps
.ind_level
= ps
.i_l_follow
;
91 ++ps
.i_l_follow
; /* subsequent statements should be indented 1 */
92 ps
.search_brace
= btype_2
;
95 case lbrace
: /* scanned { */
96 break_comma
= false; /* don't break comma in an initial list */
97 if (ps
.p_stack
[ps
.tos
] == stmt
|| ps
.p_stack
[ps
.tos
] == decl
98 || ps
.p_stack
[ps
.tos
] == stmtl
)
99 ++ps
.i_l_follow
; /* it is a random, isolated stmt group or a
102 if (s_code
== e_code
) {
104 * only do this if there is nothing on the line
108 * it is a group as part of a while, for, etc.
110 if (ps
.p_stack
[ps
.tos
] == swstmt
&& ps
.case_indent
>= 1)
113 * for a switch, brace should be two levels out from the code
118 ps
.p_stack
[++ps
.tos
] = lbrace
;
119 ps
.il
[ps
.tos
] = ps
.ind_level
;
120 ps
.p_stack
[++ps
.tos
] = stmt
;
121 /* allow null stmt between braces */
122 ps
.il
[ps
.tos
] = ps
.i_l_follow
;
125 case whilestmt
: /* scanned while (...) */
126 if (ps
.p_stack
[ps
.tos
] == dohead
) {
127 /* it is matched with do stmt */
128 ps
.ind_level
= ps
.i_l_follow
= ps
.il
[ps
.tos
];
129 ps
.p_stack
[++ps
.tos
] = whilestmt
;
130 ps
.il
[ps
.tos
] = ps
.ind_level
= ps
.i_l_follow
;
132 else { /* it is a while loop */
133 ps
.p_stack
[++ps
.tos
] = whilestmt
;
134 ps
.il
[ps
.tos
] = ps
.i_l_follow
;
136 ps
.search_brace
= btype_2
;
141 case elselit
: /* scanned an else */
143 if (ps
.p_stack
[ps
.tos
] != ifhead
)
144 diag2(1, "Unmatched 'else'");
146 ps
.ind_level
= ps
.il
[ps
.tos
]; /* indentation for else should
147 * be same as for if */
148 ps
.i_l_follow
= ps
.ind_level
+ 1; /* everything following should
150 ps
.p_stack
[ps
.tos
] = elsehead
;
151 /* remember if with else */
152 ps
.search_brace
= btype_2
| ps
.else_if
;
156 case rbrace
: /* scanned a } */
157 /* stack should have <lbrace> <stmt> or <lbrace> <stmtl> */
158 if (ps
.p_stack
[ps
.tos
- 1] == lbrace
) {
159 ps
.ind_level
= ps
.i_l_follow
= ps
.il
[--ps
.tos
];
160 ps
.p_stack
[ps
.tos
] = stmt
;
163 diag2(1, "Statement nesting error");
166 case swstmt
: /* had switch (...) */
167 ps
.p_stack
[++ps
.tos
] = swstmt
;
168 ps
.cstk
[ps
.tos
] = case_ind
;
169 /* save current case indent level */
170 ps
.il
[ps
.tos
] = ps
.i_l_follow
;
171 case_ind
= ps
.i_l_follow
+ ps
.case_indent
; /* cases should be one
174 ps
.i_l_follow
+= ps
.case_indent
+ 1; /* statements should be two
176 ps
.search_brace
= btype_2
;
179 case semicolon
: /* this indicates a simple stmt */
180 break_comma
= false; /* turn off flag to break after commas in a
182 ps
.p_stack
[++ps
.tos
] = stmt
;
183 ps
.il
[ps
.tos
] = ps
.ind_level
;
186 default: /* this is an error */
187 diag2(1, "Unknown code to parser");
191 } /* end of switch */
193 reduce(); /* see if any reduction can be done */
196 for (i
= 1; i
<= ps
.tos
; ++i
)
197 printf("(%d %d)", ps
.p_stack
[i
], ps
.il
[i
]);
207 * FUNCTION: Implements the reduce part of the parsing algorithm
209 * ALGORITHM: The following reductions are done. Reductions are repeated
210 * until no more are possible.
213 * <stmt> <stmt> <stmtl>
214 * <stmtl> <stmt> <stmtl>
217 * switch <stmt> <stmt>
219 * "ifelse" <stmt> <stmt>
221 * while <stmt> <stmt>
222 * "dostmt" while <stmt>
224 * On each reduction, ps.i_l_follow (the indentation for the following line)
225 * is set to the indentation level associated with the old TOS.
231 * GLOBALS: ps.cstk ps.i_l_follow = ps.il ps.p_stack = ps.tos =
237 * HISTORY: initial coding November 1976 D A Willcox of CAC
240 /*----------------------------------------------*\
242 \*----------------------------------------------*/
248 for (;;) { /* keep looping until there is nothing left to
251 switch (ps
.p_stack
[ps
.tos
]) {
254 switch (ps
.p_stack
[ps
.tos
- 1]) {
258 /* stmtl stmt or stmt stmt */
259 ps
.p_stack
[--ps
.tos
] = stmtl
;
262 case dolit
: /* <do> <stmt> */
263 ps
.p_stack
[--ps
.tos
] = dohead
;
264 ps
.i_l_follow
= ps
.il
[ps
.tos
];
269 ps
.p_stack
[--ps
.tos
] = ifhead
;
272 ps
.p_stack
[i
] != stmt
274 ps
.p_stack
[i
] != stmtl
276 ps
.p_stack
[i
] != lbrace
279 ps
.i_l_follow
= ps
.il
[i
];
281 * for the time being, we will assume that there is no else on
282 * this if, and set the indentation level accordingly. If an
283 * else is scanned, it will be fixed up later
288 /* <switch> <stmt> */
289 case_ind
= ps
.cstk
[ps
.tos
- 1];
291 case decl
: /* finish of a declaration */
293 /* <<if> <stmt> else> <stmt> */
298 ps
.p_stack
[--ps
.tos
] = stmt
;
299 ps
.i_l_follow
= ps
.il
[ps
.tos
];
302 default: /* <anything else> <stmt> */
305 } /* end of section for <stmt> on top of stack */
308 case whilestmt
: /* while (...) on top */
309 if (ps
.p_stack
[ps
.tos
- 1] == dohead
) {
310 /* it is termination of a do while */
317 default: /* anything else on top */