[unix-history] / usr / src / old / dbx / tree.c

/* Copyright (c) 1982 Regents of the University of California */

static char sccsid[] = "@(#)tree.c 1.2 %G%";

/*
 * Parse tree management.
 */

#include "defs.h"
#include "tree.h"
#include "operators.h"
#include "eval.h"
#include "events.h"
#include "symbols.h"
#include "scanner.h"
#include "source.h"
#include "object.h"
#include "mappings.h"
#include "process.h"
#include "machine.h"

#ifndef public
#include "lists.h"

typedef struct Node *Node;
typedef Node Command;
typedef List Cmdlist;

#include "operators.h"
#include "symbols.h"
#include "events.h"

#define MAXNARGS 5

struct Node {
    Operator op;
    Symbol nodetype;
    union treevalue {
	Symbol sym;
	Name name;
	long lcon;
	double fcon;
	String scon;
	Node arg[MAXNARGS];
	struct {
	    Node cond;
	    Cmdlist actions;
	} event;
	struct {
	    Boolean inst;
	    Event event;
	    Cmdlist actions;
	} trace;
	struct {
	    Boolean source;
	    Boolean skipcalls;
	} step;
	struct {
	    String mode;
	    Node beginaddr;
	    Node endaddr;
	    Integer count;
	} examine;
    } value;
};

#define evalcmd(cmd) eval(cmd)
#define cmdlist_append(cmd, cl) list_append(list_item(cmd), nil, cl)

#endif

typedef char *Arglist;

#define nextarg(type)  ((type *) (ap += sizeof(type)))[-1]

/*
 * Build a tree.
 */

/* VARARGS1 */
public Node build(op, args)
Operator op;
{
    register Node p, q;
    register Arglist ap;
    Integer i;

    p = new(Node);
    p->op = op;
    p->nodetype = nil;
    ap = (Arglist) &args;
    switch (op) {
	case O_NAME:
	    p->value.name = nextarg(Name);
	    break;

	case O_SYM:
	case O_PRINTCALL:
	case O_PRINTRTN:
	case O_PROCRTN:
	    p->value.sym = nextarg(Symbol);
	    break;

	case O_LCON:
	case O_DELETE:
	case O_CATCH:
	case O_IGNORE:
	case O_TRACEOFF:
	    p->value.lcon = nextarg(long);
	    break;

	case O_FCON:
	    p->value.fcon = nextarg(double);
	    break;

	case O_SCON:
	case O_CHFILE:
	case O_EDIT:
	case O_SOURCE:
	    p->value.scon = nextarg(String);
	    break;

	case O_RVAL:
	    q = nextarg(Node);
	    if (q->op == O_CALL) {
		*p = *q;
		dispose(q);
	    } else {
		p->value.arg[0] = q;
	    }
	    break;

	case O_INDIR:
	    q = nextarg(Node);
	    if (q != nil and q->op == O_RVAL) {
		p->value.arg[0] = q->value.arg[0];
		dispose(q);
	    } else {
		p->value.arg[0] = q;
	    }
	    break;

	case O_ADDEVENT:
	case O_ONCE:
	case O_IF:
	    p->value.event.cond = nextarg(Node);
	    p->value.event.actions = nextarg(Cmdlist);
	    break;

	case O_TRACEON:
	    p->value.trace.inst = nextarg(Boolean);
	    p->value.trace.event = nil;
	    p->value.trace.actions = nextarg(Cmdlist);
	    break;

	case O_STEP:
	    p->value.step.source = nextarg(Boolean);
	    p->value.step.skipcalls = nextarg(Boolean);
	    break;

	case O_EXAMINE:
	    p->value.examine.mode = nextarg(String);
	    p->value.examine.beginaddr = nextarg(Node);
	    p->value.examine.endaddr = nextarg(Node);
	    p->value.examine.count = nextarg(Integer);
	    break;

	default:
	    for (i = 0; i < nargs(op); i++) {
		p->value.arg[i] = nextarg(Node);
	    }
	    break;
    }
    check(p);
    assigntypes(p);
    return p;
}

/*
 * Create a command list from a single command.
 */

public Cmdlist buildcmdlist(cmd)
Command cmd;
{
    Cmdlist cmdlist;

    cmdlist = list_alloc();
    cmdlist_append(cmd, cmdlist);
    return cmdlist;
}

/*
 * Return the tree for a unary ampersand operator.
 */

public Node amper(p)
Node p;
{
    Node r;

    checkref(p);
    switch (p->op) {
	case O_RVAL:
	    r = p->value.arg[0];
	    break;

	case O_CALL:
	    r = build(O_LCON, codeloc(p->value.arg[0]->value.sym));
	    tfree(p);
	    break;

	case O_SYM:
	    if (isblock(p->value.sym)) {
		r = build(O_LCON, codeloc(p->value.sym));
	    } else {
		r = build(O_LCON, address(p->value.sym, nil));
	    }
	    tfree(p);
	    break;

	case O_DOT:
	    r = p;
	    break;

	case O_INDIR:
	    r = p->value.arg[0];
	    dispose(p);
	    break;

	default:
	    beginerrmsg();
	    fprintf(stderr, "expected variable, found ");
	    prtree(stderr, p);
	    tfree(p);
	    enderrmsg();
	    /* NOTREACHED */
    }
    r->nodetype = t_int;
    return r;
}

/*
 * Create a "concrete" version of a node.
 * This is necessary when the type of the node contains
 * an unresolved type reference.
 */

public Node concrete(p)
Node p;
{
    findtype(p->nodetype);
    return build(O_INDIR, p);
}

/*
 * Print out a command.
 */

public printcmd(f, cmd)
File f;
Command cmd;
{
    register Integer i;
    register Command c;
    register Node p;

    switch (cmd->op) {
	case O_PRINTIFCHANGED:
	case O_PRINTSRCPOS:
	case O_STOPIFCHANGED:
	case O_TRACEON:
	    break;

	case O_STEP:
	    if (cmd->value.step.skipcalls) {
		fprintf(f, "next");
	    } else {
		fprintf(f, "step");
	    }
	    if (not cmd->value.step.source) {
		fprintf(f, "i");
	    }
	    break;

	default:
	    fprintf(f, "%s", opinfo[ord(cmd->op)].opstring);
	    if (nargs(cmd->op) != 0) {
		fprintf(f, " ");
	    }
	    break;
    }
    switch (cmd->op) {
	case O_PRINTCALL:
	case O_PRINTRTN:
	case O_PROCRTN:
	    fprintf(f, "%s", symname(cmd->value.sym));
	    break;

	case O_PRINTSRCPOS:
	    p = cmd->value.arg[0];
	    if (p != nil and p->op != O_QLINE) {
		printf("trace ");
		prtree(f, p);
	    }
	    break;

	case O_CHFILE:
	case O_EDIT:
	case O_SOURCE:
	    fprintf(f, "%s", cmd->value.scon);
	    break;

	case O_DELETE:
	case O_CATCH:
	case O_IGNORE:
	case O_TRACEOFF:
	    fprintf(f, "%d", cmd->value.lcon);
	    break;

	case O_ADDEVENT:
	case O_ONCE:
	case O_IF:
	    fprintf(f, " ");
	    prtree(f, cmd->value.event.cond);
	    fprintf(f, " { ");
	    foreach (Command, c, cmd->value.event.actions)
		printcmd(f, c);
		if (not list_islast()) {
		    fprintf(f, ";");
		}
	    endfor
	    fprintf(f, " }", opinfo[ord(cmd->op)].opstring);
	    break;

	case O_TRACEON:
	    print_tracestop(f, cmd);
	    break;

	case O_EXAMINE:
	    prtree(f, cmd->value.examine.beginaddr);
	    if (cmd->value.examine.endaddr != nil) {
		fprintf(f, ",");
		prtree(f, cmd->value.examine.endaddr);
	    }
	    fprintf(f, "/");
	    if (cmd->value.examine.count > 1) {
		fprintf(f, "%d", cmd->value.examine.count);
	    }
	    fprintf("%s", cmd->value.examine.mode);
	    break;

	default:
	    if (nargs(cmd->op) != 0) {
		i = 0;
		for (;;) {
		    prtree(f, cmd->value.arg[i]);
		    ++i;
		if (i >= nargs(cmd->op)) break;
		    fprintf(f, " ");
		}
	    }
	    break;
    }
}

/*
 * Print out a trace/stop command name.
 */

private print_tracestop(f, cmd)
File f;
Command cmd;
{
    register Command c, ifcmd, stopcmd;
    Boolean done;

    done = false;
    ifcmd = list_element(Command, list_head(cmd->value.trace.actions));
    checkref(ifcmd);
    if (ifcmd->op == O_IF) {
	stopcmd = list_element(Command, list_head(ifcmd->value.event.actions));
	checkref(stopcmd);
	if (stopcmd->op == O_STOPX) {
	    fprintf(f, "%s if ", cmd->value.trace.inst ? "stopi" : "stop");
	    prtree(f, ifcmd->value.event.cond);
	    done = true;
	}
    }
    if (not done) {
	fprintf(f, "%s ", cmd->value.trace.inst ? "tracei" : "trace");
	foreach (Command, c, cmd->value.trace.actions)
	    printcmd(f, c);
	    if (not list_islast()) {
		fprintf(f, ";");
	    }
	endfor
    }
}

/*
 * Print a tree back out in Pascal form.
 */

public prtree(f, p)
File f;
register Node p;
{
    register Node q;
    Operator op;

    if (p != nil) {
	op = p->op;
	if (ord(op) > ord(O_LASTOP)) {
	    panic("bad op %d in prtree", p->op);
	}
	switch (op) {
	    case O_NAME:
		fprintf(f, "%s", ident(p->value.name));
		break;

	    case O_SYM:
		printname(f, p->value.sym);
		break;

	    case O_QLINE:
		if (nlhdr.nfiles > 1) {
		    prtree(f, p->value.arg[0]);
		    fprintf(f, ":");
		}
		prtree(f, p->value.arg[1]);
		break;

	    case O_LCON:
		if (compatible(p->nodetype, t_char)) {
		    fprintf(f, "'%c'", p->value.lcon);
		} else {
		    fprintf(f, "%d", p->value.lcon);
		}
		break;

	    case O_FCON:
		fprintf(f, "%g", p->value.fcon);
		break;

	    case O_SCON:
		fprintf(f, "\"%s\"", p->value.scon);
		break;

	    case O_INDEX:
		prtree(f, p->value.arg[0]);
		fprintf(f, "[");
		prtree(f, p->value.arg[1]);
		fprintf(f, "]");
		break;

	    case O_COMMA:
		prtree(f, p->value.arg[0]);
		if (p->value.arg[1] != nil) {
		    fprintf(f, ", ");
		    prtree(f, p->value.arg[1]);
		}
		break;

	    case O_RVAL:
		if (p->value.arg[0]->op == O_SYM) {
		    printname(f, p->value.arg[0]->value.sym);
		} else {
		    prtree(f, p->value.arg[0]);
		}
		break;

	    case O_ITOF:
		prtree(f, p->value.arg[0]);
		break;

	    case O_CALL:
		prtree(f, p->value.arg[0]);
		if (p->value.arg[1]!= nil) {
		    fprintf(f, "(");
		    prtree(f, p->value.arg[1]);
		    fprintf(f, ")");
		}
		break;

	    case O_INDIR:
		q = p->value.arg[0];
		if (isvarparam(q->nodetype)) {
		    prtree(f, q);
		} else {
		    if (q->op == O_SYM or q->op == O_LCON or q->op == O_DOT) {
			prtree(f, q);
			fprintf(f, "^");
		    } else {
			fprintf(f, "*(");
			prtree(f, q);
			fprintf(f, ")");
		    }
		}
		break;

	    case O_DOT:
		q = p->value.arg[0];
		if (q->op == O_INDIR) {
		    prtree(f, q->value.arg[0]);
		} else {
		    prtree(f, q);
		}
		fprintf(f, ".%s", symname(p->value.arg[1]->value.sym));
		break;

	    default:
		switch (degree(op)) {
		    case BINARY:
			prtree(f, p->value.arg[0]);
			fprintf(f, "%s", opinfo[ord(op)].opstring);
			prtree(f, p->value.arg[1]);
			break;

		    case UNARY:
			fprintf(f, "%s", opinfo[ord(op)].opstring);
			prtree(f, p->value.arg[0]);
			break;

		    default:
			error("internal error: bad op %d in prtree", op);
		}
		break;
	}
    }
}

/*
 * Free storage associated with a tree.
 */

public tfree(p)
Node p;
{
    Integer i;

    if (p == nil) {
	return;
    }
    switch (p->op) {
	case O_QLINE:
	    dispose(p->value.arg[0]->value.scon);
	    dispose(p->value.arg[0]);
	    tfree(p->value.arg[1]);
	    break;

	case O_SCON:
	    unmkstring(p->nodetype);
	    dispose(p->nodetype);
	    dispose(p->value.scon);
	    break;

	default:
	    for (i = 0; i < nargs(p->op); i++) {
		tfree(p->value.arg[i]);
	    }
	    break;
    }
    dispose(p);
}

/*
 * A recursive tree search routine to test if two trees * are equivalent.
 */

public Boolean tr_equal(t1, t2)
register Node t1;
register Node t2;
{
    register Boolean b;

    if (t1 == nil and t2 == nil) {
	b = true;
    } else if (t1 == nil or t2 == nil) {
	b = false;
    } else if (t1->op != t2->op or degree(t1->op) != degree(t2->op)) {
	b = false;
    } else {
	switch (degree(t1->op)) {
	    case LEAF:
		switch (t1->op) {
		    case O_NAME:
			b = (Boolean) (t1->value.name == t2->value.name);
			break;

		    case O_SYM:
			b = (Boolean) (t1->value.sym == t2->value.sym);
			break;

		    case O_LCON:
			b = (Boolean) (t1->value.lcon == t2->value.lcon);
			break;

		    case O_FCON:
			b = (Boolean) (t1->value.fcon == t2->value.fcon);
			break;

		    case O_SCON:
			b = (Boolean) (t1->value.scon == t2->value.scon);
			break;

		    default:
			panic("tr_equal: leaf %d\n", t1->op);
		}
		/*NOTREACHED*/

	    case BINARY:
		if (not tr_equal(t1->value.arg[0], t2->value.arg[0])) {
		    b = false;
		} else {
		    b = tr_equal(t1->value.arg[1], t2->value.arg[1]);
		}
		break;

	    case UNARY:
		b = tr_equal(t1->value.arg[0], t2->value.arg[0]);
		break;

	    default:
		panic("tr_equal: bad degree for op %d\n", t1->op);
	}
    }
    return b;
}
Commit	Line	Data
b3355c51 ML	1	/* Copyright (c) 1982 Regents of the University of California */
b3355c51 ML	2
550fe947	3	static char sccsid[] = "@(#)tree.c 1.2 %G%";
b3355c51 ML	4
	5	/*
	6	* Parse tree management.
	7	*/
	8
	9	#include "defs.h"
	10	#include "tree.h"
	11	#include "operators.h"
	12	#include "eval.h"
	13	#include "events.h"
	14	#include "symbols.h"
	15	#include "scanner.h"
	16	#include "source.h"
	17	#include "object.h"
	18	#include "mappings.h"
	19	#include "process.h"
	20	#include "machine.h"
	21
	22	#ifndef public
	23	#include "lists.h"
	24
	25	typedef struct Node *Node;
	26	typedef Node Command;
	27	typedef List Cmdlist;
	28
	29	#include "operators.h"
	30	#include "symbols.h"
	31	#include "events.h"
	32
	33	#define MAXNARGS 5
	34
	35	struct Node {
	36	Operator op;
	37	Symbol nodetype;
	38	union treevalue {
	39	Symbol sym;
	40	Name name;
	41	long lcon;
	42	double fcon;
	43	String scon;
	44	Node arg[MAXNARGS];
	45	struct {
	46	Node cond;
	47	Cmdlist actions;
	48	} event;
	49	struct {
	50	Boolean inst;
	51	Event event;
	52	Cmdlist actions;
	53	} trace;
	54	struct {
	55	Boolean source;
	56	Boolean skipcalls;
	57	} step;
	58	struct {
	59	String mode;
	60	Node beginaddr;
	61	Node endaddr;
	62	Integer count;
	63	} examine;
	64	} value;
	65	};
	66
	67	#define evalcmd(cmd) eval(cmd)
68	#define cmdlist_append(cmd, cl) list_append(list_item(cmd), nil, cl)
69
70	#endif
71
72	typedef char *Arglist;
73
74	#define nextarg(type) ((type *) (ap += sizeof(type)))[-1]
75
76	/*
77	* Build a tree.
78	*/
79
80	/* VARARGS1 */
81	public Node build(op, args)
82	Operator op;
83	{
84	register Node p, q;
85	register Arglist ap;
86	Integer i;
87
88	p = new(Node);
89	p->op = op;
90	p->nodetype = nil;
91	ap = (Arglist) &args;
92	switch (op) {
93	case O_NAME:
94	p->value.name = nextarg(Name);
95	break;
96
97	case O_SYM:
98	case O_PRINTCALL:
99	case O_PRINTRTN:
100	case O_PROCRTN:
101	p->value.sym = nextarg(Symbol);
102	break;
103
104	case O_LCON:
105	case O_DELETE:
106	case O_CATCH:
107	case O_IGNORE:
108	case O_TRACEOFF:
109	p->value.lcon = nextarg(long);
110	break;
111
112	case O_FCON:
113	p->value.fcon = nextarg(double);
114	break;
115
116	case O_SCON:
117	case O_CHFILE:
118	case O_EDIT:
119	case O_SOURCE:
120	p->value.scon = nextarg(String);
121	break;
122
123	case O_RVAL:
124	q = nextarg(Node);
125	if (q->op == O_CALL) {
126	p = q;
127	dispose(q);
128	} else {
129	p->value.arg[0] = q;
130	}
131	break;
132
133	case O_INDIR:
134	q = nextarg(Node);
135	if (q != nil and q->op == O_RVAL) {
136	p->value.arg[0] = q->value.arg[0];
137	dispose(q);
138	} else {
139	p->value.arg[0] = q;
140	}
141	break;
142
143	case O_ADDEVENT:
144	case O_ONCE:
145	case O_IF:
146	p->value.event.cond = nextarg(Node);
147	p->value.event.actions = nextarg(Cmdlist);
148	break;
149
150	case O_TRACEON:
151	p->value.trace.inst = nextarg(Boolean);
152	p->value.trace.event = nil;
153	p->value.trace.actions = nextarg(Cmdlist);
154	break;
155
156	case O_STEP:
157	p->value.step.source = nextarg(Boolean);
158	p->value.step.skipcalls = nextarg(Boolean);
159	break;
160
161	case O_EXAMINE:
162	p->value.examine.mode = nextarg(String);
163	p->value.examine.beginaddr = nextarg(Node);
164	p->value.examine.endaddr = nextarg(Node);
165	p->value.examine.count = nextarg(Integer);
166	break;
167
168	default:
169	for (i = 0; i < nargs(op); i++) {
170	p->value.arg[i] = nextarg(Node);
171	}
172	break;
173	}
174	check(p);
175	assigntypes(p);
176	return p;
177	}
178
179	/*
180	* Create a command list from a single command.
181	*/
182
183	public Cmdlist buildcmdlist(cmd)
184	Command cmd;
185	{
186	Cmdlist cmdlist;
187
188	cmdlist = list_alloc();
189	cmdlist_append(cmd, cmdlist);
190	return cmdlist;
191	}
192
193	/*
194	* Return the tree for a unary ampersand operator.
195	*/
196
197	public Node amper(p)
198	Node p;
199	{
200	Node r;
201
202	checkref(p);
203	switch (p->op) {
204	case O_RVAL:
205	r = p->value.arg[0];
206	break;
207
208	case O_CALL:
209	r = build(O_LCON, codeloc(p->value.arg[0]->value.sym));
210	tfree(p);
211	break;
212
213	case O_SYM:
214	if (isblock(p->value.sym)) {
215	r = build(O_LCON, codeloc(p->value.sym));
216	} else {
217	r = build(O_LCON, address(p->value.sym, nil));
218	}
219	tfree(p);
220	break;
221
222	case O_DOT:
223	r = p;
224	break;
225
226	case O_INDIR:
227	r = p->value.arg[0];
228	dispose(p);
229	break;
230
231	default:
232	beginerrmsg();
233	fprintf(stderr, "expected variable, found ");
234	prtree(stderr, p);
235	tfree(p);
236	enderrmsg();
237	/* NOTREACHED */
238	}
239	r->nodetype = t_int;
240	return r;
241	}
242
243	/*
244	* Create a "concrete" version of a node.
245	* This is necessary when the type of the node contains
246	* an unresolved type reference.
247	*/
248
249	public Node concrete(p)
250	Node p;
251	{
252	findtype(p->nodetype);
253	return build(O_INDIR, p);
254	}
255
256	/*
257	* Print out a command.
258	*/
259
260	public printcmd(f, cmd)
261	File f;
262	Command cmd;
263	{
264	register Integer i;
265	register Command c;
266	register Node p;
267
268	switch (cmd->op) {
269	case O_PRINTIFCHANGED:
270	case O_PRINTSRCPOS:
271	case O_STOPIFCHANGED:
272	case O_TRACEON:
273	break;
274
275	case O_STEP:
276	if (cmd->value.step.skipcalls) {
277	fprintf(f, "next");
278	} else {
279	fprintf(f, "step");
280	}
281	if (not cmd->value.step.source) {
282	fprintf(f, "i");
283	}
284	break;
285
286	default:
287	fprintf(f, "%s", opinfo[ord(cmd->op)].opstring);
288	if (nargs(cmd->op) != 0) {
289	fprintf(f, " ");
290	}
291	break;
292	}
293	switch (cmd->op) {
294	case O_PRINTCALL:
295	case O_PRINTRTN:
296	case O_PROCRTN:
297	fprintf(f, "%s", symname(cmd->value.sym));
298	break;
299
300	case O_PRINTSRCPOS:
301	p = cmd->value.arg[0];
302	if (p != nil and p->op != O_QLINE) {
303	printf("trace ");
304	prtree(f, p);
305	}
306	break;
307
308	case O_CHFILE:
309	case O_EDIT:
310	case O_SOURCE:
311	fprintf(f, "%s", cmd->value.scon);
312	break;
313
314	case O_DELETE:
315	case O_CATCH:
316	case O_IGNORE:
317	case O_TRACEOFF:
318	fprintf(f, "%d", cmd->value.lcon);
319	break;
320
321	case O_ADDEVENT:
322	case O_ONCE:
323	case O_IF:
324	fprintf(f, " ");
325	prtree(f, cmd->value.event.cond);
326	fprintf(f, " { ");
327	foreach (Command, c, cmd->value.event.actions)
328	printcmd(f, c);
329	if (not list_islast()) {
330	fprintf(f, ";");
331	}
332	endfor
333	fprintf(f, " }", opinfo[ord(cmd->op)].opstring);
334	break;
335
336	case O_TRACEON:
337	print_tracestop(f, cmd);
338	break;
339
340	case O_EXAMINE:
341	prtree(f, cmd->value.examine.beginaddr);
342	if (cmd->value.examine.endaddr != nil) {
343	fprintf(f, ",");
344	prtree(f, cmd->value.examine.endaddr);
345	}
346	fprintf(f, "/");
347	if (cmd->value.examine.count > 1) {
348	fprintf(f, "%d", cmd->value.examine.count);
349	}
350	fprintf("%s", cmd->value.examine.mode);
351	break;
352
353	default:
354	if (nargs(cmd->op) != 0) {
355	i = 0;
356	for (;;) {
357	prtree(f, cmd->value.arg[i]);
358	++i;
359	if (i >= nargs(cmd->op)) break;
360	fprintf(f, " ");
361	}
362	}
363	break;
364	}
365	}
366
367	/*
368	* Print out a trace/stop command name.
369	*/
370
371	private print_tracestop(f, cmd)
372	File f;
373	Command cmd;
374	{
375	register Command c, ifcmd, stopcmd;
376	Boolean done;
377
378	done = false;
379	ifcmd = list_element(Command, list_head(cmd->value.trace.actions));
380	checkref(ifcmd);
381	if (ifcmd->op == O_IF) {
382	stopcmd = list_element(Command, list_head(ifcmd->value.event.actions));
383	checkref(stopcmd);
384	if (stopcmd->op == O_STOPX) {
385	fprintf(f, "%s if ", cmd->value.trace.inst ? "stopi" : "stop");
386	prtree(f, ifcmd->value.event.cond);
387	done = true;
388	}
389	}
390	if (not done) {
391	fprintf(f, "%s ", cmd->value.trace.inst ? "tracei" : "trace");
392	foreach (Command, c, cmd->value.trace.actions)
393	printcmd(f, c);
394	if (not list_islast()) {
395	fprintf(f, ";");
396	}
397	endfor
398	}
399	}
400
401	/*
402	* Print a tree back out in Pascal form.
403	*/
404
405	public prtree(f, p)
406	File f;
407	register Node p;
408	{
409	register Node q;
410	Operator op;
411
412	if (p != nil) {
413	op = p->op;
414	if (ord(op) > ord(O_LASTOP)) {
415	panic("bad op %d in prtree", p->op);
416	}
417	switch (op) {
418	case O_NAME:
419	fprintf(f, "%s", ident(p->value.name));
420	break;
421
422	case O_SYM:
423	printname(f, p->value.sym);
424	break;
425
426	case O_QLINE:
427	if (nlhdr.nfiles > 1) {
428	prtree(f, p->value.arg[0]);
429	fprintf(f, ":");
430	}
431	prtree(f, p->value.arg[1]);
432	break;
433
434	case O_LCON:
435	if (compatible(p->nodetype, t_char)) {
436	fprintf(f, "'%c'", p->value.lcon);
437	} else {
438	fprintf(f, "%d", p->value.lcon);
439	}
440	break;
441
442	case O_FCON:
443	fprintf(f, "%g", p->value.fcon);
444	break;
445
446	case O_SCON:
447	fprintf(f, "\"%s\"", p->value.scon);
448	break;
449
450	case O_INDEX:
451	prtree(f, p->value.arg[0]);
452	fprintf(f, "[");
453	prtree(f, p->value.arg[1]);
454	fprintf(f, "]");
455	break;
456
457	case O_COMMA:
458	prtree(f, p->value.arg[0]);
459	if (p->value.arg[1] != nil) {
460	fprintf(f, ", ");
461	prtree(f, p->value.arg[1]);
462	}
463	break;
464
465	case O_RVAL:
466	if (p->value.arg[0]->op == O_SYM) {
467	printname(f, p->value.arg[0]->value.sym);
468	} else {
469	prtree(f, p->value.arg[0]);
470	}
471	break;
472
473	case O_ITOF:
474	prtree(f, p->value.arg[0]);
475	break;
476
477	case O_CALL:
478	prtree(f, p->value.arg[0]);
479	if (p->value.arg[1]!= nil) {
480	fprintf(f, "(");
481	prtree(f, p->value.arg[1]);
482	fprintf(f, ")");
483	}
484	break;
485
486	case O_INDIR:
487	q = p->value.arg[0];
488	if (isvarparam(q->nodetype)) {
489	prtree(f, q);
490	} else {
491	if (q->op == O_SYM or q->op == O_LCON or q->op == O_DOT) {
492	prtree(f, q);
493	fprintf(f, "^");
494	} else {
495	fprintf(f, "*(");
496	prtree(f, q);
497	fprintf(f, ")");
498	}
499	}
500	break;
501
502	case O_DOT:
503	q = p->value.arg[0];
504	if (q->op == O_INDIR) {
505	prtree(f, q->value.arg[0]);
506	} else {
507	prtree(f, q);
508	}
509	fprintf(f, ".%s", symname(p->value.arg[1]->value.sym));
510	break;
511
512	default:
513	switch (degree(op)) {
514	case BINARY:
515	prtree(f, p->value.arg[0]);
516	fprintf(f, "%s", opinfo[ord(op)].opstring);
517	prtree(f, p->value.arg[1]);
518	break;
519
520	case UNARY:
521	fprintf(f, "%s", opinfo[ord(op)].opstring);
522	prtree(f, p->value.arg[0]);
523	break;
524
525	default:
526	error("internal error: bad op %d in prtree", op);
527	}
528	break;
529	}
530	}
531	}
532
533	/*
534	* Free storage associated with a tree.
535	*/
536
537	public tfree(p)
538	Node p;
539	{
540	Integer i;
541
542	if (p == nil) {
543	return;
544	}
545	switch (p->op) {
546	case O_QLINE:
547	dispose(p->value.arg[0]->value.scon);
548	dispose(p->value.arg[0]);
549	tfree(p->value.arg[1]);
550	break;
551
552	case O_SCON:
553	unmkstring(p->nodetype);
554	dispose(p->nodetype);
555	dispose(p->value.scon);
556	break;
557
558	default:
559	for (i = 0; i < nargs(p->op); i++) {
560	tfree(p->value.arg[i]);
561	}
562	break;
563	}
564	dispose(p);
565	}
566
567	/*
568	* A recursive tree search routine to test if two trees * are equivalent.
569	*/
570
571	public Boolean tr_equal(t1, t2)
572	register Node t1;
573	register Node t2;
574	{
575	register Boolean b;
576
577	if (t1 == nil and t2 == nil) {
578	b = true;
579	} else if (t1 == nil or t2 == nil) {
580	b = false;
581	} else if (t1->op != t2->op or degree(t1->op) != degree(t2->op)) {
582	b = false;
583	} else {
584	switch (degree(t1->op)) {
585	case LEAF:
586	switch (t1->op) {
587	case O_NAME:
588	b = (Boolean) (t1->value.name == t2->value.name);
589	break;
590
591	case O_SYM:
592	b = (Boolean) (t1->value.sym == t2->value.sym);
593	break;
594
595	case O_LCON:
596	b = (Boolean) (t1->value.lcon == t2->value.lcon);
597	break;
598
599	case O_FCON:
600	b = (Boolean) (t1->value.fcon == t2->value.fcon);
601	break;
602
603	case O_SCON:
604	b = (Boolean) (t1->value.scon == t2->value.scon);
605	break;
606
607	default:
608	panic("tr_equal: leaf %d\n", t1->op);
609	}
610	/NOTREACHED/
611
612	case BINARY:
613	if (not tr_equal(t1->value.arg[0], t2->value.arg[0])) {
614	b = false;
615	} else {
616	b = tr_equal(t1->value.arg[1], t2->value.arg[1]);
617	}
618	break;
619
620	case UNARY:
621	b = tr_equal(t1->value.arg[0], t2->value.arg[0]);
622	break;
623
624	default:
625	panic("tr_equal: bad degree for op %d\n", t1->op);
626	}
627	}
628	return b;
629	}