Annotation of src/usr.bin/indent/parse.c, Revision 1.1.1.1
1.1 deraadt 1: /*
2: * Copyright (c) 1985 Sun Microsystems, Inc.
3: * Copyright (c) 1980 The Regents of the University of California.
4: * Copyright (c) 1976 Board of Trustees of the University of Illinois.
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[] = "from: @(#)parse.c 5.12 (Berkeley) 2/26/91";*/
38: static char rcsid[] = "$Id: parse.c,v 1.2 1993/08/01 18:14:30 mycroft Exp $";
39: #endif /* not lint */
40:
41: #include <stdio.h>
42: #include "indent_globs.h"
43: #include "indent_codes.h"
44:
45: parse(tk)
46: int tk; /* the code for the construct scanned */
47: {
48: int i;
49:
50: #ifdef debug
51: printf("%2d - %s\n", tk, token);
52: #endif
53:
54: while (ps.p_stack[ps.tos] == ifhead && tk != elselit) {
55: /* true if we have an if without an else */
56: ps.p_stack[ps.tos] = stmt; /* apply the if(..) stmt ::= stmt
57: * reduction */
58: reduce(); /* see if this allows any reduction */
59: }
60:
61:
62: switch (tk) { /* go on and figure out what to do with the
63: * input */
64:
65: case decl: /* scanned a declaration word */
66: ps.search_brace = btype_2;
67: /* indicate that following brace should be on same line */
68: if (ps.p_stack[ps.tos] != decl) { /* only put one declaration
69: * onto stack */
70: break_comma = true; /* while in declaration, newline should be
71: * forced after comma */
72: ps.p_stack[++ps.tos] = decl;
73: ps.il[ps.tos] = ps.i_l_follow;
74:
75: if (ps.ljust_decl) {/* only do if we want left justified
76: * declarations */
77: ps.ind_level = 0;
78: for (i = ps.tos - 1; i > 0; --i)
79: if (ps.p_stack[i] == decl)
80: ++ps.ind_level; /* indentation is number of
81: * declaration levels deep we are */
82: ps.i_l_follow = ps.ind_level;
83: }
84: }
85: break;
86:
87: case ifstmt: /* scanned if (...) */
88: if (ps.p_stack[ps.tos] == elsehead && ps.else_if) /* "else if ..." */
89: ps.i_l_follow = ps.il[ps.tos];
90: case dolit: /* 'do' */
91: case forstmt: /* for (...) */
92: ps.p_stack[++ps.tos] = tk;
93: ps.il[ps.tos] = ps.ind_level = ps.i_l_follow;
94: ++ps.i_l_follow; /* subsequent statements should be indented 1 */
95: ps.search_brace = btype_2;
96: break;
97:
98: case lbrace: /* scanned { */
99: break_comma = false; /* don't break comma in an initial list */
100: if (ps.p_stack[ps.tos] == stmt || ps.p_stack[ps.tos] == decl
101: || ps.p_stack[ps.tos] == stmtl)
102: ++ps.i_l_follow; /* it is a random, isolated stmt group or a
103: * declaration */
104: else {
105: if (s_code == e_code) {
106: /*
107: * only do this if there is nothing on the line
108: */
109: --ps.ind_level;
110: /*
111: * it is a group as part of a while, for, etc.
112: */
113: if (ps.p_stack[ps.tos] == swstmt && ps.case_indent >= 1)
114: --ps.ind_level;
115: /*
116: * for a switch, brace should be two levels out from the code
117: */
118: }
119: }
120:
121: ps.p_stack[++ps.tos] = lbrace;
122: ps.il[ps.tos] = ps.ind_level;
123: ps.p_stack[++ps.tos] = stmt;
124: /* allow null stmt between braces */
125: ps.il[ps.tos] = ps.i_l_follow;
126: break;
127:
128: case whilestmt: /* scanned while (...) */
129: if (ps.p_stack[ps.tos] == dohead) {
130: /* it is matched with do stmt */
131: ps.ind_level = ps.i_l_follow = ps.il[ps.tos];
132: ps.p_stack[++ps.tos] = whilestmt;
133: ps.il[ps.tos] = ps.ind_level = ps.i_l_follow;
134: }
135: else { /* it is a while loop */
136: ps.p_stack[++ps.tos] = whilestmt;
137: ps.il[ps.tos] = ps.i_l_follow;
138: ++ps.i_l_follow;
139: ps.search_brace = btype_2;
140: }
141:
142: break;
143:
144: case elselit: /* scanned an else */
145:
146: if (ps.p_stack[ps.tos] != ifhead)
147: diag(1, "Unmatched 'else'");
148: else {
149: ps.ind_level = ps.il[ps.tos]; /* indentation for else should
150: * be same as for if */
151: ps.i_l_follow = ps.ind_level + 1; /* everything following should
152: * be in 1 level */
153: ps.p_stack[ps.tos] = elsehead;
154: /* remember if with else */
155: ps.search_brace = btype_2 | ps.else_if;
156: }
157: break;
158:
159: case rbrace: /* scanned a } */
160: /* stack should have <lbrace> <stmt> or <lbrace> <stmtl> */
161: if (ps.p_stack[ps.tos - 1] == lbrace) {
162: ps.ind_level = ps.i_l_follow = ps.il[--ps.tos];
163: ps.p_stack[ps.tos] = stmt;
164: }
165: else
166: diag(1, "Stmt nesting error.");
167: break;
168:
169: case swstmt: /* had switch (...) */
170: ps.p_stack[++ps.tos] = swstmt;
171: ps.cstk[ps.tos] = case_ind;
172: /* save current case indent level */
173: ps.il[ps.tos] = ps.i_l_follow;
174: case_ind = ps.i_l_follow + ps.case_indent; /* cases should be one
175: * level down from
176: * switch */
177: ps.i_l_follow += ps.case_indent + 1; /* statements should be two
178: * levels in */
179: ps.search_brace = btype_2;
180: break;
181:
182: case semicolon: /* this indicates a simple stmt */
183: break_comma = false; /* turn off flag to break after commas in a
184: * declaration */
185: ps.p_stack[++ps.tos] = stmt;
186: ps.il[ps.tos] = ps.ind_level;
187: break;
188:
189: default: /* this is an error */
190: diag(1, "Unknown code to parser");
191: return;
192:
193:
194: } /* end of switch */
195:
196: reduce(); /* see if any reduction can be done */
197:
198: #ifdef debug
199: for (i = 1; i <= ps.tos; ++i)
200: printf("(%d %d)", ps.p_stack[i], ps.il[i]);
201: printf("\n");
202: #endif
203:
204: return;
205: }
206:
207: /*
208: * NAME: reduce
209: *
210: * FUNCTION: Implements the reduce part of the parsing algorithm
211: *
212: * ALGORITHM: The following reductions are done. Reductions are repeated
213: * until no more are possible.
214: *
215: * Old TOS New TOS
216: * <stmt> <stmt> <stmtl>
217: * <stmtl> <stmt> <stmtl>
218: * do <stmt> "dostmt"
219: * if <stmt> "ifstmt"
220: * switch <stmt> <stmt>
221: * decl <stmt> <stmt>
222: * "ifelse" <stmt> <stmt>
223: * for <stmt> <stmt>
224: * while <stmt> <stmt>
225: * "dostmt" while <stmt>
226: *
227: * On each reduction, ps.i_l_follow (the indentation for the following line)
228: * is set to the indentation level associated with the old TOS.
229: *
230: * PARAMETERS: None
231: *
232: * RETURNS: Nothing
233: *
234: * GLOBALS: ps.cstk ps.i_l_follow = ps.il ps.p_stack = ps.tos =
235: *
236: * CALLS: None
237: *
238: * CALLED BY: parse
239: *
240: * HISTORY: initial coding November 1976 D A Willcox of CAC
241: *
242: */
243: /*----------------------------------------------*\
244: | REDUCTION PHASE |
245: \*----------------------------------------------*/
246: reduce()
247: {
248:
249: register int i;
250:
251: for (;;) { /* keep looping until there is nothing left to
252: * reduce */
253:
254: switch (ps.p_stack[ps.tos]) {
255:
256: case stmt:
257: switch (ps.p_stack[ps.tos - 1]) {
258:
259: case stmt:
260: case stmtl:
261: /* stmtl stmt or stmt stmt */
262: ps.p_stack[--ps.tos] = stmtl;
263: break;
264:
265: case dolit: /* <do> <stmt> */
266: ps.p_stack[--ps.tos] = dohead;
267: ps.i_l_follow = ps.il[ps.tos];
268: break;
269:
270: case ifstmt:
271: /* <if> <stmt> */
272: ps.p_stack[--ps.tos] = ifhead;
273: for (i = ps.tos - 1;
274: (
275: ps.p_stack[i] != stmt
276: &&
277: ps.p_stack[i] != stmtl
278: &&
279: ps.p_stack[i] != lbrace
280: );
281: --i);
282: ps.i_l_follow = ps.il[i];
283: /*
284: * for the time being, we will assume that there is no else on
285: * this if, and set the indentation level accordingly. If an
286: * else is scanned, it will be fixed up later
287: */
288: break;
289:
290: case swstmt:
291: /* <switch> <stmt> */
292: case_ind = ps.cstk[ps.tos - 1];
293:
294: case decl: /* finish of a declaration */
295: case elsehead:
296: /* <<if> <stmt> else> <stmt> */
297: case forstmt:
298: /* <for> <stmt> */
299: case whilestmt:
300: /* <while> <stmt> */
301: ps.p_stack[--ps.tos] = stmt;
302: ps.i_l_follow = ps.il[ps.tos];
303: break;
304:
305: default: /* <anything else> <stmt> */
306: return;
307:
308: } /* end of section for <stmt> on top of stack */
309: break;
310:
311: case whilestmt: /* while (...) on top */
312: if (ps.p_stack[ps.tos - 1] == dohead) {
313: /* it is termination of a do while */
314: ps.p_stack[--ps.tos] = stmt;
315: break;
316: }
317: else
318: return;
319:
320: default: /* anything else on top */
321: return;
322:
323: }
324: }
325: }
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