xref: /plan9/sys/src/libmach/machdata.c (revision ff8c3af2f44d95267f67219afa20ba82ff6cf7e4)
1 /*
2  * Debugger utilities shared by at least two architectures
3  */
4 
5 #include <u.h>
6 #include <libc.h>
7 #include <bio.h>
8 #include <mach.h>
9 
10 #define STARTSYM	"_main"
11 #define PROFSYM		"_mainp"
12 #define	FRAMENAME	".frame"
13 
14 extern	Machdata	mipsmach;
15 
16 int	asstype = AMIPS;		/* disassembler type */
17 Machdata *machdata;		/* machine-dependent functions */
18 
19 int
20 localaddr(Map *map, char *fn, char *var, long *r, Rgetter rget)
21 {
22 	Symbol s;
23 	ulong fp;
24 	ulong pc, sp, link;
25 
26 	if (!lookup(fn, 0, &s)) {
27 		werrstr("function not found");
28 		return -1;
29 	}
30 	pc = rget(map, mach->pc);
31 	sp = rget(map, mach->sp);
32 	if(mach->link)
33 		link = rget(map, mach->link);
34 	else
35 		link = 0;
36 	fp = machdata->findframe(map, s.value, pc, sp, link);
37 	if (fp == 0) {
38 		werrstr("stack frame not found");
39 		return -1;
40 	}
41 
42 	if (!var || !var[0]) {
43 		*r = fp;
44 		return 1;
45 	}
46 
47 	if (findlocal(&s, var, &s) == 0) {
48 		werrstr("local variable not found");
49 		return -1;
50 	}
51 
52 	switch (s.class) {
53 	case CAUTO:
54 		*r = fp - s.value;
55 		break;
56 	case CPARAM:		/* assume address size is stack width */
57 		*r = fp + s.value + mach->szaddr;
58 		break;
59 	default:
60 		werrstr("local variable not found: %d", s.class);
61 		return -1;
62 	}
63 	return 1;
64 }
65 
66 /*
67  * Print value v as name[+offset] and then the string s.
68  */
69 int
70 symoff(char *buf, int n, long v, int space)
71 {
72 	Symbol s;
73 	int r;
74 	long delta;
75 
76 	r = delta = 0;		/* to shut compiler up */
77 	if (v) {
78 		r = findsym(v, space, &s);
79 		if (r)
80 			delta = v-s.value;
81 		if (delta < 0)
82 			delta = -delta;
83 	}
84 	if (v == 0 || r == 0)
85 		return snprint(buf, n, "%lux", v);
86 	if (s.type != 't' && s.type != 'T' && delta >= 4096)
87 		return snprint(buf, n, "%lux", v);
88 	else if (delta)
89 		return snprint(buf, n, "%s+%lux", s.name, delta);
90 	else
91 		return snprint(buf, n, "%s", s.name);
92 }
93 /*
94  *	Format floating point registers
95  *
96  *	Register codes in format field:
97  *	'X' - print as 32-bit hexadecimal value
98  *	'F' - 64-bit double register when modif == 'F'; else 32-bit single reg
99  *	'f' - 32-bit ieee float
100  *	'8' - big endian 80-bit ieee extended float
101  *	'3' - little endian 80-bit ieee extended float with hole in bytes 8&9
102  */
103 int
104 fpformat(Map *map, Reglist *rp, char *buf, int n, int modif)
105 {
106 	char reg[12];
107 	long r;
108 
109 	switch(rp->rformat)
110 	{
111 	case 'X':
112 		if (get4(map, rp->roffs, &r) < 0)
113 			return -1;
114 		snprint(buf, n, "%lux", r);
115 		break;
116 	case 'F':	/* first reg of double reg pair */
117 		if (modif == 'F')
118 		if ((rp->rformat=='F') || (((rp+1)->rflags&RFLT) && (rp+1)->rformat == 'f')) {
119 			if (get1(map, rp->roffs, (uchar *)reg, 8) < 0)
120 				return -1;
121 			machdata->dftos(buf, n, reg);
122 			if (rp->rformat == 'F')
123 				return 1;
124 			return 2;
125 		}
126 			/* treat it like 'f' */
127 		if (get1(map, rp->roffs, (uchar *)reg, 4) < 0)
128 			return -1;
129 		machdata->sftos(buf, n, reg);
130 		break;
131 	case 'f':	/* 32 bit float */
132 		if (get1(map, rp->roffs, (uchar *)reg, 4) < 0)
133 			return -1;
134 		machdata->sftos(buf, n, reg);
135 		break;
136 	case '3':	/* little endian ieee 80 with hole in bytes 8&9 */
137 		if (get1(map, rp->roffs, (uchar *)reg, 10) < 0)
138 			return -1;
139 		memmove(reg+10, reg+8, 2);	/* open hole */
140 		memset(reg+8, 0, 2);		/* fill it */
141 		leieee80ftos(buf, n, reg);
142 		break;
143 	case '8':	/* big-endian ieee 80 */
144 		if (get1(map, rp->roffs, (uchar *)reg, 10) < 0)
145 			return -1;
146 		beieee80ftos(buf, n, reg);
147 		break;
148 	default:	/* unknown */
149 		break;
150 	}
151 	return 1;
152 }
153 
154 char *
155 _hexify(char *buf, ulong p, int zeros)
156 {
157 	ulong d;
158 
159 	d = p/16;
160 	if(d)
161 		buf = _hexify(buf, d, zeros-1);
162 	else
163 		while(zeros--)
164 			*buf++ = '0';
165 	*buf++ = "0123456789abcdef"[p&0x0f];
166 	return buf;
167 }
168 
169 /*
170  * These routines assume that if the number is representable
171  * in IEEE floating point, it will be representable in the native
172  * double format.  Naive but workable, probably.
173  */
174 int
175 ieeedftos(char *buf, int n, ulong h, ulong l)
176 {
177 	double fr;
178 	int exp;
179 
180 	if (n <= 0)
181 		return 0;
182 
183 
184 	if(h & (1L<<31)){
185 		*buf++ = '-';
186 		h &= ~(1L<<31);
187 	}else
188 		*buf++ = ' ';
189 	n--;
190 	if(l == 0 && h == 0)
191 		return snprint(buf, n, "0.");
192 	exp = (h>>20) & ((1L<<11)-1L);
193 	if(exp == 0)
194 		return snprint(buf, n, "DeN(%.8lux%.8lux)", h, l);
195 	if(exp == ((1L<<11)-1L)){
196 		if(l==0 && (h&((1L<<20)-1L)) == 0)
197 			return snprint(buf, n, "Inf");
198 		else
199 			return snprint(buf, n, "NaN(%.8lux%.8lux)", h&((1L<<20)-1L), l);
200 	}
201 	exp -= (1L<<10) - 2L;
202 	fr = l & ((1L<<16)-1L);
203 	fr /= 1L<<16;
204 	fr += (l>>16) & ((1L<<16)-1L);
205 	fr /= 1L<<16;
206 	fr += (h & (1L<<20)-1L) | (1L<<20);
207 	fr /= 1L<<21;
208 	fr = ldexp(fr, exp);
209 	return snprint(buf, n, "%.18g", fr);
210 }
211 
212 int
213 ieeesftos(char *buf, int n, ulong h)
214 {
215 	double fr;
216 	int exp;
217 
218 	if (n <= 0)
219 		return 0;
220 
221 	if(h & (1L<<31)){
222 		*buf++ = '-';
223 		h &= ~(1L<<31);
224 	}else
225 		*buf++ = ' ';
226 	n--;
227 	if(h == 0)
228 		return snprint(buf, n, "0.");
229 	exp = (h>>23) & ((1L<<8)-1L);
230 	if(exp == 0)
231 		return snprint(buf, n, "DeN(%.8lux)", h);
232 	if(exp == ((1L<<8)-1L)){
233 		if((h&((1L<<23)-1L)) == 0)
234 			return snprint(buf, n, "Inf");
235 		else
236 			return snprint(buf, n, "NaN(%.8lux)", h&((1L<<23)-1L));
237 	}
238 	exp -= (1L<<7) - 2L;
239 	fr = (h & ((1L<<23)-1L)) | (1L<<23);
240 	fr /= 1L<<24;
241 	fr = ldexp(fr, exp);
242 	return snprint(buf, n, "%.9g", fr);
243 }
244 
245 int
246 beieeesftos(char *buf, int n, void *s)
247 {
248 	return ieeesftos(buf, n, beswal(*(ulong*)s));
249 }
250 
251 int
252 beieeedftos(char *buf, int n, void *s)
253 {
254 	return ieeedftos(buf, n, beswal(*(ulong*)s), beswal(((ulong*)(s))[1]));
255 }
256 
257 int
258 leieeesftos(char *buf, int n, void *s)
259 {
260 	return ieeesftos(buf, n, leswal(*(ulong*)s));
261 }
262 
263 int
264 leieeedftos(char *buf, int n, void *s)
265 {
266 	return ieeedftos(buf, n, leswal(((ulong*)(s))[1]), leswal(*(ulong*)s));
267 }
268 
269 /* packed in 12 bytes, with s[2]==s[3]==0; mantissa starts at s[4]*/
270 int
271 beieee80ftos(char *buf, int n, void *s)
272 {
273 	uchar *reg = (uchar*)s;
274 	int i;
275 	ulong x;
276 	uchar ieee[8+8];	/* room for slop */
277 	uchar *p, *q;
278 
279 	memset(ieee, 0, sizeof(ieee));
280 	/* sign */
281 	if(reg[0] & 0x80)
282 		ieee[0] |= 0x80;
283 
284 	/* exponent */
285 	x = ((reg[0]&0x7F)<<8) | reg[1];
286 	if(x == 0)		/* number is ±0 */
287 		goto done;
288 	if(x == 0x7FFF){
289 		if(memcmp(reg+4, ieee+1, 8) == 0){ /* infinity */
290 			x = 2047;
291 		}else{				/* NaN */
292 			x = 2047;
293 			ieee[7] = 0x1;		/* make sure */
294 		}
295 		ieee[0] |= x>>4;
296 		ieee[1] |= (x&0xF)<<4;
297 		goto done;
298 	}
299 	x -= 0x3FFF;		/* exponent bias */
300 	x += 1023;
301 	if(x >= (1<<11) || ((reg[4]&0x80)==0 && x!=0))
302 		return snprint(buf, n, "not in range");
303 	ieee[0] |= x>>4;
304 	ieee[1] |= (x&0xF)<<4;
305 
306 	/* mantissa */
307 	p = reg+4;
308 	q = ieee+1;
309 	for(i=0; i<56; i+=8, p++, q++){	/* move one byte */
310 		x = (p[0]&0x7F) << 1;
311 		if(p[1] & 0x80)
312 			x |= 1;
313 		q[0] |= x>>4;
314 		q[1] |= (x&0xF)<<4;
315 	}
316     done:
317 	return beieeedftos(buf, n, (void*)ieee);
318 }
319 
320 
321 int
322 leieee80ftos(char *buf, int n, void *s)
323 {
324 	int i;
325 	char *cp;
326 	char b[12];
327 
328 	cp = (char*) s;
329 	for(i=0; i<12; i++)
330 		b[11-i] = *cp++;
331 	return beieee80ftos(buf, n, b);
332 }
333 
334 int
335 cisctrace(Map *map, ulong pc, ulong sp, ulong link, Tracer trace)
336 {
337 	Symbol s;
338 	int found;
339 	ulong opc;
340 	long moved, j;
341 
342 	USED(link);
343 	j = 0;
344 	opc = 0;
345 	while(pc && opc != pc) {
346 		moved = pc2sp(pc);
347 		if (moved == -1)
348 			break;
349 		found = findsym(pc, CTEXT, &s);
350 		if (!found)
351 			break;
352 		if(strcmp(STARTSYM, s.name) == 0 || strcmp(PROFSYM, s.name) == 0)
353 			break;
354 
355 		sp += moved;
356 		opc = pc;
357 		if (get4(map, sp, (long *)&pc) < 0)
358 			break;
359 		(*trace)(map, pc, sp, &s);
360 		sp += mach->szaddr;	/*assumes address size = stack width*/
361 		if(++j > 40)
362 			break;
363 	}
364 	return j;
365 }
366 
367 int
368 risctrace(Map *map, ulong pc, ulong sp, ulong link, Tracer trace)
369 {
370 	int i;
371 	Symbol s, f;
372 	ulong oldpc;
373 
374 	i = 0;
375 	while(findsym(pc, CTEXT, &s)) {
376 		if(strcmp(STARTSYM, s.name) == 0 || strcmp(PROFSYM, s.name) == 0)
377 			break;
378 
379 		if(pc == s.value)	/* at first instruction */
380 			f.value = 0;
381 		else if(findlocal(&s, FRAMENAME, &f) == 0)
382 			break;
383 
384 		oldpc = pc;
385 		if(s.type == 'L' || s.type == 'l' || pc <= s.value+mach->pcquant)
386 			pc = link;
387 		else
388 			if (get4(map, sp, (long *) &pc) < 0)
389 				break;
390 
391 		if(pc == 0 || (pc == oldpc && f.value == 0))
392 			break;
393 
394 		sp += f.value;
395 		(*trace)(map, pc-8, sp, &s);
396 
397 		if(++i > 40)
398 			break;
399 	}
400 	return i;
401 }
402 
403 ulong
404 ciscframe(Map *map, ulong addr, ulong pc, ulong sp, ulong link)
405 {
406 	Symbol s;
407 	int moved;
408 
409 	USED(link);
410 	for(;;) {
411 		moved = pc2sp(pc);
412 		if (moved  == -1)
413 			break;
414 		sp += moved;
415 		findsym(pc, CTEXT, &s);
416 		if (addr == s.value)
417 			return sp;
418 		if (get4(map, sp, (long *) &pc) < 0)
419 			break;
420 		sp += mach->szaddr;	/*assumes sizeof(addr) = stack width*/
421 	}
422 	return 0;
423 }
424 
425 ulong
426 riscframe(Map *map, ulong addr, ulong pc, ulong sp, ulong link)
427 {
428 	Symbol s, f;
429 
430 	while (findsym(pc, CTEXT, &s)) {
431 		if(strcmp(STARTSYM, s.name) == 0 || strcmp(PROFSYM, s.name) == 0)
432 			break;
433 
434 		if(pc == s.value)	/* at first instruction */
435 			f.value = 0;
436 		else
437 		if(findlocal(&s, FRAMENAME, &f) == 0)
438 			break;
439 
440 		sp += f.value;
441 		if (s.value == addr)
442 			return sp;
443 
444 		if (s.type == 'L' || s.type == 'l' || pc-s.value <= mach->szaddr*2)
445 			pc = link;
446 		else
447 		if (get4(map, sp-f.value, (long *)&pc) < 0)
448 			break;
449 	}
450 	return 0;
451 }
452