#ifndef lintstatic char sccsid[] = "@(#)tree.c	4.1	(Berkeley)	2/11/83";#endif not lint# include "y.tab.h"#include "b.h"#include <stdio.h>char *malloc();struct node *addroot(string,type,n1,n2)char *string;int type;struct node *n1, *n2;	{	struct node *p;	p = (struct node *)malloc(sizeof(*p));	p->left = n1;	p->right = n2;	p->op = type;	p->lit = malloc(slength(string) + 1);	str_copy(string,p->lit,slength(string) + 1);	return(p);	}freetree(tree)struct node *tree;	{	if (tree)		{freetree(tree->left);		freetree(tree->right);		freenode(tree);		}	}freenode(treenode)struct node *treenode;	{	free(treenode->lit);	free(treenode);	}int compop[] = { '&',	'|',	'<',	'>',	xxeq,	xxle,	xxne,	xxge};int notop[] = { '|',	'&',	xxge,	xxle,	xxne,	'>',	xxeq,	'<'};char *opstring[] =	{ "||",  "&&",	">=",	"<=", "!=",	">",	"==",	"<"};struct node *checkneg(tree,neg)		/* eliminate nots if possible */struct node *tree;int neg;	{	int i;	struct node *t;	if (!tree) return(0);	for (i =  0; i < 8; ++i)		if (tree->op == compop[i]) break;	if (i > 1 && i <  8 && tree ->left ->op == '-' && str_eq(tree->right->lit,"0"))		{		t = tree->right;		tree->right = tree->left->right;		freenode(t);		t = tree->left;		tree->left = tree->left->left;		freenode(t);		}	if (neg)		{		if (tree ->op == '!')			{			t = tree->left;			freenode(tree);			return(checkneg(t,0));			}			if (i < 8)				{				tree->op = notop[i];				free(tree->lit);				tree->lit = malloc(slength(opstring[i])+1);				str_copy(opstring[i],tree->lit, slength(opstring[i])+1);				if (tree->op == '&' || tree->op == '|')					{					tree->left = checkneg(tree->left,1);					tree->right = checkneg(tree->right,1);					}				return(tree);				}		if (tree->op == xxident && str_eq(tree->lit,".false."))			str_copy(".true.",tree->lit, slength(".true.")+1);		else if (tree->op == xxident && str_eq(tree->lit,".true."))			{			free(tree->lit);			tree->lit = malloc(slength(".false.")+1);			str_copy(".false.",tree->lit, slength(".false.")+1);			}		else			{			tree = addroot("!",'!',tree,0);			tree->lit = malloc(2);			str_copy("!",tree->lit, slength("!")+1);			}		return(tree);		}	else		if (tree->op == '!')			{			t = tree;			tree = tree->left;			freenode(t);			return(checkneg(tree,1));			}	else		{tree->left = checkneg(tree->left,0);		tree->right = checkneg(tree->right,0);		return(tree);		}	}yield(tree,fprec)struct node *tree;int fprec;				/* fprec is precedence of father of this node */	{	int paren,p;	static int oplast;			/* oplast = 1 iff last char printed was operator */	if (!tree) return;	p = prec(tree ->op);	paren = (p < fprec || (oplast && tree->op == xxuminus)) ? 1 : 0;	if (paren)		{		putout('(',"(");		oplast = 0;		}	switch(tree->op)		{		case xxuminus:			tree->op = '-';		case '!':			putout(tree->op,tree->lit);			oplast = 1;			yield(tree->left,p);			break;		case '&':		case '|':		case '<':		case '>':		case xxeq:		case xxle:		case xxge:		case '+':		case '-':		case '*':		case '/':		case '^':			yield(tree->left,p);			putout(tree->op, tree->lit);			oplast = 1;			yield(tree->right,p);			break;		case xxidpar:			yield(tree->left,0);			putout('(',"(");			oplast = 0;			yield(tree->right,0);			putout('(',")");			oplast = 0;			break;		default:			yield(tree->left,p);			putout(tree->op, tree->lit);			oplast = 0;			yield(tree->right,p);			break;		}	if (paren)		{		putout(')',")");		oplast = 0;		}	}puttree(tree)struct node *tree;	{	yield(tree,0);	freetree(tree);	}prec(oper)int oper;	{	switch(oper)		{		case ',':		return(0);		case '|':	return(1);		case '&':	return(2);		case '!':	return(3);		case '<':		case '>':		case xxeq:		case xxne:	case xxle:	case xxge:				return(4);		case '+':	case '-':		return(5);		case '*':	case '/':		return(6);		case xxuminus:	return(7);		case '^':	return(8);		default:	return(9);		}	}str_copy(s,ptr,length)	/* copy s at ptr, return length of s */char *s, *ptr;int length;	{int i;	for (i = 0; i < length; i++)		{		ptr[i] = s[i];		if (ptr[i] == '\0')			return(i + 1);		}	fprintf(2,"string %s too long to be copied by str_copy at address %d\n",			*s,ptr);	exit(1);	}str_eq(s,t)char s[],t[];	{int j;	for (j = 0; s[j] == t[j]; j++)		{if (s[j] == '\0') return(1);}	return(0);	}slength(s)			/* return number of chars in s, not counting '\0' */char *s;	{	int i;	if (!s) return(-1);	for (i = 0; s[i] != '\0'; i++);	return(i);	}