2 * Copyright (c) 1985 Sun Microsystems, Inc.
3 * Copyright (c) 1980, 1993
4 * The Regents of the University of California. All rights reserved.
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16 * must display the following acknowledgement:
17 * This product includes software developed by the University of
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35 * @(#)parse.c 8.1 (Berkeley) 6/6/93
36 * $FreeBSD: src/usr.bin/indent/parse.c,v 1.10 2003/06/15 09:28:17 charnier Exp $
40 #include "indent_globs.h"
41 #include "indent_codes.h"
44 static void reduce(void);
47 parse(int tk) /* tk: the code for the construct scanned */
52 printf("%2d - %s\n", tk, token);
55 while (ps.p_stack[ps.tos] == ifhead && tk != elselit) {
56 /* true if we have an if without an else */
57 ps.p_stack[ps.tos] = stmt; /* apply the if(..) stmt ::= stmt
59 reduce(); /* see if this allows any reduction */
63 switch (tk) { /* go on and figure out what to do with the
66 case decl: /* scanned a declaration word */
67 ps.search_brace = btype_2;
68 /* indicate that following brace should be on same line */
69 if (ps.p_stack[ps.tos] != decl) { /* only put one declaration
71 break_comma = true; /* while in declaration, newline should be
72 * forced after comma */
73 ps.p_stack[++ps.tos] = decl;
74 ps.il[ps.tos] = ps.i_l_follow;
76 if (ps.ljust_decl) {/* only do if we want left justified
79 for (i = ps.tos - 1; i > 0; --i)
80 if (ps.p_stack[i] == decl)
81 ++ps.ind_level; /* indentation is number of
82 * declaration levels deep we are */
83 ps.i_l_follow = ps.ind_level;
88 case ifstmt: /* scanned if (...) */
89 if (ps.p_stack[ps.tos] == elsehead && ps.else_if) /* "else if ..." */
90 ps.i_l_follow = ps.il[ps.tos];
91 case dolit: /* 'do' */
92 case forstmt: /* for (...) */
93 ps.p_stack[++ps.tos] = tk;
94 ps.il[ps.tos] = ps.ind_level = ps.i_l_follow;
95 ++ps.i_l_follow; /* subsequent statements should be indented 1 */
96 ps.search_brace = btype_2;
99 case lbrace: /* scanned { */
100 break_comma = false; /* don't break comma in an initial list */
101 if (ps.p_stack[ps.tos] == stmt || ps.p_stack[ps.tos] == decl
102 || ps.p_stack[ps.tos] == stmtl)
103 ++ps.i_l_follow; /* it is a random, isolated stmt group or a
106 if (s_code == e_code) {
108 * only do this if there is nothing on the line
112 * it is a group as part of a while, for, etc.
114 if (ps.p_stack[ps.tos] == swstmt && ps.case_indent >= 1)
117 * for a switch, brace should be two levels out from the code
122 ps.p_stack[++ps.tos] = lbrace;
123 ps.il[ps.tos] = ps.ind_level;
124 ps.p_stack[++ps.tos] = stmt;
125 /* allow null stmt between braces */
126 ps.il[ps.tos] = ps.i_l_follow;
129 case whilestmt: /* scanned while (...) */
130 if (ps.p_stack[ps.tos] == dohead) {
131 /* it is matched with do stmt */
132 ps.ind_level = ps.i_l_follow = ps.il[ps.tos];
133 ps.p_stack[++ps.tos] = whilestmt;
134 ps.il[ps.tos] = ps.ind_level = ps.i_l_follow;
136 else { /* it is a while loop */
137 ps.p_stack[++ps.tos] = whilestmt;
138 ps.il[ps.tos] = ps.i_l_follow;
140 ps.search_brace = btype_2;
145 case elselit: /* scanned an else */
147 if (ps.p_stack[ps.tos] != ifhead)
148 diag2(1, "Unmatched 'else'");
150 ps.ind_level = ps.il[ps.tos]; /* indentation for else should
151 * be same as for if */
152 ps.i_l_follow = ps.ind_level + 1; /* everything following should
154 ps.p_stack[ps.tos] = elsehead;
155 /* remember if with else */
156 ps.search_brace = btype_2 | ps.else_if;
160 case rbrace: /* scanned a } */
161 /* stack should have <lbrace> <stmt> or <lbrace> <stmtl> */
162 if (ps.p_stack[ps.tos - 1] == lbrace) {
163 ps.ind_level = ps.i_l_follow = ps.il[--ps.tos];
164 ps.p_stack[ps.tos] = stmt;
167 diag2(1, "Statement nesting error");
170 case swstmt: /* had switch (...) */
171 ps.p_stack[++ps.tos] = swstmt;
172 ps.cstk[ps.tos] = case_ind;
173 /* save current case indent level */
174 ps.il[ps.tos] = ps.i_l_follow;
175 case_ind = ps.i_l_follow + ps.case_indent; /* cases should be one
178 ps.i_l_follow += ps.case_indent + 1; /* statements should be two
180 ps.search_brace = btype_2;
183 case semicolon: /* this indicates a simple stmt */
184 break_comma = false; /* turn off flag to break after commas in a
186 ps.p_stack[++ps.tos] = stmt;
187 ps.il[ps.tos] = ps.ind_level;
190 default: /* this is an error */
191 diag2(1, "Unknown code to parser");
195 } /* end of switch */
197 reduce(); /* see if any reduction can be done */
200 for (i = 1; i <= ps.tos; ++i)
201 printf("(%d %d)", ps.p_stack[i], ps.il[i]);
211 * FUNCTION: Implements the reduce part of the parsing algorithm
213 * ALGORITHM: The following reductions are done. Reductions are repeated
214 * until no more are possible.
217 * <stmt> <stmt> <stmtl>
218 * <stmtl> <stmt> <stmtl>
221 * switch <stmt> <stmt>
223 * "ifelse" <stmt> <stmt>
225 * while <stmt> <stmt>
226 * "dostmt" while <stmt>
228 * On each reduction, ps.i_l_follow (the indentation for the following line)
229 * is set to the indentation level associated with the old TOS.
235 * GLOBALS: ps.cstk ps.i_l_follow = ps.il ps.p_stack = ps.tos =
241 * HISTORY: initial coding November 1976 D A Willcox of CAC
244 /*----------------------------------------------*\
246 \*----------------------------------------------*/
252 for (;;) { /* keep looping until there is nothing left to
255 switch (ps.p_stack[ps.tos]) {
258 switch (ps.p_stack[ps.tos - 1]) {
262 /* stmtl stmt or stmt stmt */
263 ps.p_stack[--ps.tos] = stmtl;
266 case dolit: /* <do> <stmt> */
267 ps.p_stack[--ps.tos] = dohead;
268 ps.i_l_follow = ps.il[ps.tos];
273 ps.p_stack[--ps.tos] = ifhead;
276 ps.p_stack[i] != stmt
278 ps.p_stack[i] != stmtl
280 ps.p_stack[i] != lbrace
283 ps.i_l_follow = ps.il[i];
285 * for the time being, we will assume that there is no else on
286 * this if, and set the indentation level accordingly. If an
287 * else is scanned, it will be fixed up later
292 /* <switch> <stmt> */
293 case_ind = ps.cstk[ps.tos - 1];
295 case decl: /* finish of a declaration */
297 /* <<if> <stmt> else> <stmt> */
302 ps.p_stack[--ps.tos] = stmt;
303 ps.i_l_follow = ps.il[ps.tos];
306 default: /* <anything else> <stmt> */
309 } /* end of section for <stmt> on top of stack */
312 case whilestmt: /* while (...) on top */
313 if (ps.p_stack[ps.tos - 1] == dohead) {
314 /* it is termination of a do while */
321 default: /* anything else on top */