FreeBSD-5.3/usr.bin/indent/parse.c
/*
* Copyright (c) 1985 Sun Microsystems, Inc.
* Copyright (c) 1980, 1993
* The Regents of the University of California. All rights reserved.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#if 0
#ifndef lint
static char sccsid[] = "@(#)parse.c 8.1 (Berkeley) 6/6/93";
#endif /* not lint */
#endif
#include <sys/cdefs.h>
__FBSDID("$FreeBSD: src/usr.bin/indent/parse.c,v 1.10 2003/06/15 09:28:17 charnier Exp $");
#include <stdio.h>
#include "indent_globs.h"
#include "indent_codes.h"
#include "indent.h"
static void reduce(void);
void
parse(int tk) /* tk: the code for the construct scanned */
{
int i;
#ifdef debug
printf("%2d - %s\n", tk, token);
#endif
while (ps.p_stack[ps.tos] == ifhead && tk != elselit) {
/* true if we have an if without an else */
ps.p_stack[ps.tos] = stmt; /* apply the if(..) stmt ::= stmt
* reduction */
reduce(); /* see if this allows any reduction */
}
switch (tk) { /* go on and figure out what to do with the
* input */
case decl: /* scanned a declaration word */
ps.search_brace = btype_2;
/* indicate that following brace should be on same line */
if (ps.p_stack[ps.tos] != decl) { /* only put one declaration
* onto stack */
break_comma = true; /* while in declaration, newline should be
* forced after comma */
ps.p_stack[++ps.tos] = decl;
ps.il[ps.tos] = ps.i_l_follow;
if (ps.ljust_decl) {/* only do if we want left justified
* declarations */
ps.ind_level = 0;
for (i = ps.tos - 1; i > 0; --i)
if (ps.p_stack[i] == decl)
++ps.ind_level; /* indentation is number of
* declaration levels deep we are */
ps.i_l_follow = ps.ind_level;
}
}
break;
case ifstmt: /* scanned if (...) */
if (ps.p_stack[ps.tos] == elsehead && ps.else_if) /* "else if ..." */
ps.i_l_follow = ps.il[ps.tos];
case dolit: /* 'do' */
case forstmt: /* for (...) */
ps.p_stack[++ps.tos] = tk;
ps.il[ps.tos] = ps.ind_level = ps.i_l_follow;
++ps.i_l_follow; /* subsequent statements should be indented 1 */
ps.search_brace = btype_2;
break;
case lbrace: /* scanned { */
break_comma = false; /* don't break comma in an initial list */
if (ps.p_stack[ps.tos] == stmt || ps.p_stack[ps.tos] == decl
|| ps.p_stack[ps.tos] == stmtl)
++ps.i_l_follow; /* it is a random, isolated stmt group or a
* declaration */
else {
if (s_code == e_code) {
/*
* only do this if there is nothing on the line
*/
--ps.ind_level;
/*
* it is a group as part of a while, for, etc.
*/
if (ps.p_stack[ps.tos] == swstmt && ps.case_indent >= 1)
--ps.ind_level;
/*
* for a switch, brace should be two levels out from the code
*/
}
}
ps.p_stack[++ps.tos] = lbrace;
ps.il[ps.tos] = ps.ind_level;
ps.p_stack[++ps.tos] = stmt;
/* allow null stmt between braces */
ps.il[ps.tos] = ps.i_l_follow;
break;
case whilestmt: /* scanned while (...) */
if (ps.p_stack[ps.tos] == dohead) {
/* it is matched with do stmt */
ps.ind_level = ps.i_l_follow = ps.il[ps.tos];
ps.p_stack[++ps.tos] = whilestmt;
ps.il[ps.tos] = ps.ind_level = ps.i_l_follow;
}
else { /* it is a while loop */
ps.p_stack[++ps.tos] = whilestmt;
ps.il[ps.tos] = ps.i_l_follow;
++ps.i_l_follow;
ps.search_brace = btype_2;
}
break;
case elselit: /* scanned an else */
if (ps.p_stack[ps.tos] != ifhead)
diag2(1, "Unmatched 'else'");
else {
ps.ind_level = ps.il[ps.tos]; /* indentation for else should
* be same as for if */
ps.i_l_follow = ps.ind_level + 1; /* everything following should
* be in 1 level */
ps.p_stack[ps.tos] = elsehead;
/* remember if with else */
ps.search_brace = btype_2 | ps.else_if;
}
break;
case rbrace: /* scanned a } */
/* stack should have <lbrace> <stmt> or <lbrace> <stmtl> */
if (ps.p_stack[ps.tos - 1] == lbrace) {
ps.ind_level = ps.i_l_follow = ps.il[--ps.tos];
ps.p_stack[ps.tos] = stmt;
}
else
diag2(1, "Statement nesting error");
break;
case swstmt: /* had switch (...) */
ps.p_stack[++ps.tos] = swstmt;
ps.cstk[ps.tos] = case_ind;
/* save current case indent level */
ps.il[ps.tos] = ps.i_l_follow;
case_ind = ps.i_l_follow + ps.case_indent; /* cases should be one
* level down from
* switch */
ps.i_l_follow += ps.case_indent + 1; /* statements should be two
* levels in */
ps.search_brace = btype_2;
break;
case semicolon: /* this indicates a simple stmt */
break_comma = false; /* turn off flag to break after commas in a
* declaration */
ps.p_stack[++ps.tos] = stmt;
ps.il[ps.tos] = ps.ind_level;
break;
default: /* this is an error */
diag2(1, "Unknown code to parser");
return;
} /* end of switch */
reduce(); /* see if any reduction can be done */
#ifdef debug
for (i = 1; i <= ps.tos; ++i)
printf("(%d %d)", ps.p_stack[i], ps.il[i]);
printf("\n");
#endif
return;
}
/*
* NAME: reduce
*
* FUNCTION: Implements the reduce part of the parsing algorithm
*
* ALGORITHM: The following reductions are done. Reductions are repeated
* until no more are possible.
*
* Old TOS New TOS
* <stmt> <stmt> <stmtl>
* <stmtl> <stmt> <stmtl>
* do <stmt> "dostmt"
* if <stmt> "ifstmt"
* switch <stmt> <stmt>
* decl <stmt> <stmt>
* "ifelse" <stmt> <stmt>
* for <stmt> <stmt>
* while <stmt> <stmt>
* "dostmt" while <stmt>
*
* On each reduction, ps.i_l_follow (the indentation for the following line)
* is set to the indentation level associated with the old TOS.
*
* PARAMETERS: None
*
* RETURNS: Nothing
*
* GLOBALS: ps.cstk ps.i_l_follow = ps.il ps.p_stack = ps.tos =
*
* CALLS: None
*
* CALLED BY: parse
*
* HISTORY: initial coding November 1976 D A Willcox of CAC
*
*/
/*----------------------------------------------*\
| REDUCTION PHASE |
\*----------------------------------------------*/
static void
reduce(void)
{
int i;
for (;;) { /* keep looping until there is nothing left to
* reduce */
switch (ps.p_stack[ps.tos]) {
case stmt:
switch (ps.p_stack[ps.tos - 1]) {
case stmt:
case stmtl:
/* stmtl stmt or stmt stmt */
ps.p_stack[--ps.tos] = stmtl;
break;
case dolit: /* <do> <stmt> */
ps.p_stack[--ps.tos] = dohead;
ps.i_l_follow = ps.il[ps.tos];
break;
case ifstmt:
/* <if> <stmt> */
ps.p_stack[--ps.tos] = ifhead;
for (i = ps.tos - 1;
(
ps.p_stack[i] != stmt
&&
ps.p_stack[i] != stmtl
&&
ps.p_stack[i] != lbrace
);
--i);
ps.i_l_follow = ps.il[i];
/*
* for the time being, we will assume that there is no else on
* this if, and set the indentation level accordingly. If an
* else is scanned, it will be fixed up later
*/
break;
case swstmt:
/* <switch> <stmt> */
case_ind = ps.cstk[ps.tos - 1];
case decl: /* finish of a declaration */
case elsehead:
/* <<if> <stmt> else> <stmt> */
case forstmt:
/* <for> <stmt> */
case whilestmt:
/* <while> <stmt> */
ps.p_stack[--ps.tos] = stmt;
ps.i_l_follow = ps.il[ps.tos];
break;
default: /* <anything else> <stmt> */
return;
} /* end of section for <stmt> on top of stack */
break;
case whilestmt: /* while (...) on top */
if (ps.p_stack[ps.tos - 1] == dohead) {
/* it is termination of a do while */
ps.tos -= 2;
break;
}
else
return;
default: /* anything else on top */
return;
}
}
}