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freebsd/usr.bin/indent/parse.c
Pedro F. Giffuni df57947f08 spdx: initial adoption of licensing ID tags.
The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.

Special thanks to Wind River for providing access to "The Duke of
Highlander" tool: an older (2014) run over FreeBSD tree was useful as a
starting point.

Initially, only tag files that use BSD 4-Clause "Original" license.

RelNotes:	yes
Differential Revision:	https://reviews.freebsd.org/D13133
2017-11-18 14:26:50 +00:00

345 lines
9.3 KiB
C

/*-
* SPDX-License-Identifier: BSD-4-Clause
*
* 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("$FreeBSD$");
#include <err.h>
#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 ..." */
/*
* Note that the stack pointer here is decremented, effectively
* reducing "else if" to "if". This saves a lot of stack space
* in case of a long "if-else-if ... else-if" sequence.
*/
ps.i_l_follow = ps.il[ps.tos--];
/* the rest is the same as for dolit and forstmt */
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.tos > 0 && 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 */
if (ps.tos >= STACKSIZE - 1)
errx(1, "Parser stack overflow");
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];
/* FALLTHROUGH */
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;
}
}
}