323 lines
8.6 KiB
C
323 lines
8.6 KiB
C
/* $OpenBSD: parse.c,v 1.9 2009/10/27 23:59:39 deraadt Exp $ */
|
|
|
|
/*
|
|
* Copyright (c) 1980, 1993
|
|
* The Regents of the University of California.
|
|
* Copyright (c) 1976 Board of Trustees of the University of Illinois.
|
|
* Copyright (c) 1985 Sun Microsystems, Inc.
|
|
* 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. 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.
|
|
*/
|
|
|
|
#include <stdio.h>
|
|
#include "indent_globs.h"
|
|
#include "indent_codes.h"
|
|
|
|
void reduce(void);
|
|
|
|
void
|
|
parse(int 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)
|
|
diag(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
|
|
diag(1, "Stmt 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 */
|
|
diag(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 |
|
|
\*----------------------------------------------*/
|
|
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.p_stack[--ps.tos] = stmt;
|
|
break;
|
|
}
|
|
else
|
|
return;
|
|
|
|
default: /* anything else on top */
|
|
return;
|
|
|
|
}
|
|
}
|
|
}
|