File: [local] / src / usr.bin / yacc / mkpar.c (download)
Revision 1.19, Thu May 25 20:11:03 2017 UTC (6 years, 11 months ago) by tedu
Branch: MAIN
CVS Tags: OPENBSD_7_5_BASE, OPENBSD_7_5, OPENBSD_7_4_BASE, OPENBSD_7_4, OPENBSD_7_3_BASE, OPENBSD_7_3, OPENBSD_7_2_BASE, OPENBSD_7_2, OPENBSD_7_1_BASE, OPENBSD_7_1, OPENBSD_7_0_BASE, OPENBSD_7_0, OPENBSD_6_9_BASE, OPENBSD_6_9, OPENBSD_6_8_BASE, OPENBSD_6_8, OPENBSD_6_7_BASE, OPENBSD_6_7, OPENBSD_6_6_BASE, OPENBSD_6_6, OPENBSD_6_5_BASE, OPENBSD_6_5, OPENBSD_6_4_BASE, OPENBSD_6_4, OPENBSD_6_3_BASE, OPENBSD_6_3, OPENBSD_6_2_BASE, OPENBSD_6_2, HEAD Changes since 1.18: +11 -11 lines
fix a variety of warnings. from Brian Callahan
|
/* $OpenBSD: mkpar.c,v 1.19 2017/05/25 20:11:03 tedu Exp $ */
/* $NetBSD: mkpar.c,v 1.4 1996/03/19 03:21:39 jtc Exp $ */
/*
* Copyright (c) 1989 The Regents of the University of California.
* All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Robert Paul Corbett.
*
* 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 "defs.h"
action **parser;
int SRtotal;
int SRexpect = 0;
int RRtotal;
short *SRconflicts;
short *RRconflicts;
short *defred;
short *rules_used;
short nunused;
short final_state;
static int SRcount;
static int RRcount;
extern action *parse_actions(int);
extern action *get_shifts(int);
extern action *add_reductions(int, action *);
extern action *add_reduce(action *, int, int);
short sole_reduction(int);
void free_action_row(action *);
void find_final_state(void);
void unused_rules(void);
void remove_conflicts(void);
void total_conflicts(void);
void defreds(void);
void
make_parser(void)
{
int i;
parser = NEW2(nstates, action *);
for (i = 0; i < nstates; i++)
parser[i] = parse_actions(i);
find_final_state();
remove_conflicts();
unused_rules();
if (SRtotal + RRtotal > 0)
total_conflicts();
defreds();
}
action *
parse_actions(int stateno)
{
action *actions;
actions = get_shifts(stateno);
actions = add_reductions(stateno, actions);
return (actions);
}
action *
get_shifts(int stateno)
{
action *actions, *temp;
shifts *sp;
short *tto_state;
int i, k;
int symbol;
actions = 0;
sp = shift_table[stateno];
if (sp) {
tto_state = sp->shift;
for (i = sp->nshifts - 1; i >= 0; i--) {
k = tto_state[i];
symbol = accessing_symbol[k];
if (ISTOKEN(symbol)) {
temp = NEW(action);
temp->next = actions;
temp->symbol = symbol;
temp->number = k;
temp->prec = symbol_prec[symbol];
temp->action_code = SHIFT;
temp->assoc = symbol_assoc[symbol];
actions = temp;
}
}
}
return (actions);
}
action *
add_reductions(int stateno, action * actions)
{
int i, j, m, n;
int ruleno, tokensetsize;
unsigned *rowp;
tokensetsize = WORDSIZE(ntokens);
m = lookaheads[stateno];
n = lookaheads[stateno + 1];
for (i = m; i < n; i++) {
ruleno = LAruleno[i];
rowp = LA + i * tokensetsize;
for (j = ntokens - 1; j >= 0; j--) {
if (BIT(rowp, j))
actions = add_reduce(actions, ruleno, j);
}
}
return (actions);
}
action *
add_reduce(action * actions, int ruleno, int symbol)
{
action *temp, *prev, *next;
prev = 0;
for (next = actions; next && next->symbol < symbol; next = next->next)
prev = next;
while (next && next->symbol == symbol && next->action_code == SHIFT) {
prev = next;
next = next->next;
}
while (next && next->symbol == symbol &&
next->action_code == REDUCE && next->number < ruleno) {
prev = next;
next = next->next;
}
temp = NEW(action);
temp->next = next;
temp->symbol = symbol;
temp->number = ruleno;
temp->prec = rprec[ruleno];
temp->action_code = REDUCE;
temp->assoc = rassoc[ruleno];
if (prev)
prev->next = temp;
else
actions = temp;
return (actions);
}
void
find_final_state(void)
{
int goal, i;
short *tto_state;
shifts *p;
p = shift_table[0];
tto_state = p->shift;
goal = ritem[1];
for (i = p->nshifts - 1; i >= 0; --i) {
final_state = tto_state[i];
if (accessing_symbol[final_state] == goal)
break;
}
}
void
unused_rules(void)
{
int i;
action *p;
rules_used = calloc(nrules, sizeof(short));
if (rules_used == NULL)
no_space();
for (i = 0; i < nstates; ++i) {
for (p = parser[i]; p; p = p->next) {
if (p->action_code == REDUCE && p->suppressed == 0)
rules_used[p->number] = 1;
}
}
nunused = 0;
for (i = 3; i < nrules; ++i)
if (!rules_used[i])
++nunused;
if (nunused) {
if (nunused == 1)
fprintf(stderr, "%s: 1 rule never reduced\n", __progname);
else
fprintf(stderr, "%s: %d rules never reduced\n", __progname,
nunused);
}
}
void
remove_conflicts(void)
{
int i;
int symbol;
action *p, *pref = NULL;
SRtotal = 0;
RRtotal = 0;
SRconflicts = NEW2(nstates, short);
RRconflicts = NEW2(nstates, short);
for (i = 0; i < nstates; i++) {
SRcount = 0;
RRcount = 0;
symbol = -1;
for (p = parser[i]; p; p = p->next) {
if (p->symbol != symbol) {
pref = p;
symbol = p->symbol;
} else if (i == final_state && symbol == 0) {
SRcount++;
p->suppressed = 1;
} else if (pref->action_code == SHIFT) {
if (pref->prec > 0 && p->prec > 0) {
if (pref->prec < p->prec) {
pref->suppressed = 2;
pref = p;
} else if (pref->prec > p->prec) {
p->suppressed = 2;
} else if (pref->assoc == LEFT) {
pref->suppressed = 2;
pref = p;
} else if (pref->assoc == RIGHT) {
p->suppressed = 2;
} else {
pref->suppressed = 2;
p->suppressed = 2;
}
} else {
SRcount++;
p->suppressed = 1;
}
} else {
RRcount++;
p->suppressed = 1;
}
}
SRtotal += SRcount;
RRtotal += RRcount;
SRconflicts[i] = SRcount;
RRconflicts[i] = RRcount;
}
}
void
total_conflicts(void)
{
/* Warn if s/r != expect or if any r/r */
if ((SRtotal != SRexpect) || RRtotal) {
if (SRtotal == 1)
fprintf(stderr, "%s: %s finds 1 shift/reduce conflict\n",
input_file_name, __progname);
else if (SRtotal > 1)
fprintf(stderr, "%s: %s finds %d shift/reduce conflicts\n",
input_file_name, __progname, SRtotal);
}
if (RRtotal == 1)
fprintf(stderr, "%s: %s finds 1 reduce/reduce conflict\n",
input_file_name, __progname);
else if (RRtotal > 1)
fprintf(stderr, "%s: %s finds %d reduce/reduce conflicts\n",
input_file_name, __progname, RRtotal);
}
short
sole_reduction(int stateno)
{
int count;
short ruleno;
action *p;
count = 0;
ruleno = 0;
for (p = parser[stateno]; p; p = p->next) {
if (p->action_code == SHIFT && p->suppressed == 0)
return (0);
else if (p->action_code == REDUCE && p->suppressed == 0) {
if (ruleno > 0 && p->number != ruleno)
return (0);
if (p->symbol != 1)
++count;
ruleno = p->number;
}
}
if (count == 0)
return (0);
return (ruleno);
}
void
defreds(void)
{
int i;
defred = NEW2(nstates, short);
for (i = 0; i < nstates; i++)
defred[i] = sole_reduction(i);
}
void
free_action_row(action * p)
{
action *q;
while (p) {
q = p->next;
free(p);
p = q;
}
}
void
free_parser(void)
{
int i;
for (i = 0; i < nstates; i++)
free_action_row(parser[i]);
free(parser);
}