1 /*
2  *
3  *	debugger
4  *
5  */
6 
7 #include "defs.h"
8 #include "fns.h"
9 
10 static long	dbround(long, long);
11 
12 extern	ADDR	ditto;
13 vlong	expv;
14 
15 static WORD
16 ascval(void)
17 {
18 	Rune r;
19 
20 	if (readchar() == 0)
21 		return (0);
22 	r = lastc;
23 	while(quotchar())	/*discard chars to ending quote */
24 		;
25 	return((WORD) r);
26 }
27 
28 /*
29  * read a floating point number
30  * the result must fit in a WORD
31  */
32 
33 static WORD
34 fpin(char *buf)
35 {
36 	union {
37 		WORD w;
38 		float f;
39 	} x;
40 
41 	x.f = atof(buf);
42 	return (x.w);
43 }
44 
45 WORD
46 defval(WORD w)
47 {
48 	if (expr(0))
49 		return (expv);
50 	else
51 		return (w);
52 }
53 
54 int
55 expr(int a)
56 {	/* term | term dyadic expr |  */
57 	int	rc;
58 	WORD	lhs;
59 
60 	rdc();
61 	reread();
62 	rc=term(a);
63 	while (rc) {
64 		lhs = expv;
65 		switch ((int)readchar()) {
66 
67 		case '+':
68 			term(a|1);
69 			expv += lhs;
70 			break;
71 
72 		case '-':
73 			term(a|1);
74 			expv = lhs - expv;
75 			break;
76 
77 		case '#':
78 			term(a|1);
79 			expv = dbround(lhs,expv);
80 			break;
81 
82 		case '*':
83 			term(a|1);
84 			expv *= lhs;
85 			break;
86 
87 		case '%':
88 			term(a|1);
89 			if(expv != 0)
90 				expv = lhs/expv;
91 			else{
92 				if(lhs)
93 					expv = 1;
94 				else
95 					expv = 0;
96 			}
97 			break;
98 
99 		case '&':
100 			term(a|1);
101 			expv &= lhs;
102 			break;
103 
104 		case '|':
105 			term(a|1);
106 			expv |= lhs;
107 			break;
108 
109 		case ')':
110 			if ((a&2)==0)
111 				error("unexpected `)'");
112 
113 		default:
114 			reread();
115 			return(rc);
116 		}
117 	}
118 	return(rc);
119 }
120 
121 int
122 term(int a)
123 {	/* item | monadic item | (expr) | */
124 	u32int u;
125 
126 	switch ((int)readchar()) {
127 
128 	case '*':
129 		term(a|1);
130 		if (get4(cormap, (ADDR)expv, &u) < 0)
131 			error("%r");
132 		expv = u;
133 		return(1);
134 
135 	case '@':
136 		term(a|1);
137 		if (get4(symmap, (ADDR)expv, &u) < 0)
138 			error("%r");
139 		expv = u;
140 		return(1);
141 
142 	case '-':
143 		term(a|1);
144 		expv = -expv;
145 		return(1);
146 
147 	case '~':
148 		term(a|1);
149 		expv = ~expv;
150 		return(1);
151 
152 	case '(':
153 		expr(2);
154 		if (readchar()!=')')
155 			error("syntax error: `)' expected");
156 		return(1);
157 
158 	default:
159 		reread();
160 		return(item(a));
161 	}
162 }
163 
164 int
165 item(int a)
166 {	/* name [ . local ] | number | . | ^  | <register | 'x | | */
167 	char	*base;
168 	char	savc;
169 	u64int u;
170 	Symbol s;
171 	char gsym[MAXSYM], lsym[MAXSYM];
172 
173 	readchar();
174 	if (isfileref()) {
175 		readfname(gsym);
176 		rdc();			/* skip white space */
177 		if (lastc == ':') {	/* it better be */
178 			rdc();		/* skip white space */
179 			if (!getnum(readchar))
180 				error("bad number");
181 			if (expv == 0)
182 				expv = 1;	/* file begins at line 1 */
183 			if(file2pc(gsym, expv, &u) < 0)
184 				error("%r");
185 			expv = u;
186 			return 1;
187 		}
188 		error("bad file location");
189 	} else if (symchar(0)) {
190 		readsym(gsym);
191 		if (lastc=='.') {
192 			readchar();	/* ugh */
193 			if (lastc == '.') {
194 				lsym[0] = '.';
195 				readchar();
196 				readsym(lsym+1);
197 			} else if (symchar(0)) {
198 				readsym(lsym);
199 			} else
200 				lsym[0] = 0;
201 			if (localaddr(cormap, correg, gsym, lsym, &u) < 0)
202 				error("%r");
203 			expv = u;
204 		}
205 		else {
206 			if (lookupsym(0, gsym, &s) < 0)
207 				error("symbol not found");
208 			if (s.loc.type != LADDR)
209 				error("symbol not kept in memory");
210 			expv = s.loc.addr;
211 		}
212 		reread();
213 	} else if (getnum(readchar)) {
214 		;
215 	} else if (lastc=='.') {
216 		readchar();
217 		if (!symchar(0) && lastc != '.') {
218 			expv = dot;
219 		} else {
220 			if (findsym(locaddr(dbrget(cormap, mach->pc)), CTEXT, &s) < 0)
221 				error("no current function");
222 			if (lastc == '.') {
223 				lsym[0] = '.';
224 				readchar();
225 				readsym(lsym+1);
226 			} else
227 				readsym(lsym);
228 			if (localaddr(cormap, correg, s.name, lsym, &u) < 0)
229 				error("%r");
230 			expv = u;
231 		}
232 		reread();
233 	} else if (lastc=='"') {
234 		expv=ditto;
235 	} else if (lastc=='+') {
236 		expv=inkdot(dotinc);
237 	} else if (lastc=='^') {
238 		expv=inkdot(-dotinc);
239 	} else if (lastc=='<') {
240 		savc=rdc();
241 		base = regname(savc);
242 		expv = dbrget(cormap, base);
243 	}
244 	else if (lastc=='\'')
245 		expv = ascval();
246 	else if (a)
247 		error("address expected");
248 	else {
249 		reread();
250 		return(0);
251 	}
252 	return(1);
253 }
254 
255 #define	MAXBASE	16
256 
257 /* service routines for expression reading */
258 int
259 getnum(int (*rdf)(void))
260 {
261 	char *cp;
262 	int base, d;
263 	BOOL fpnum;
264 	char num[MAXLIN];
265 
266 	base = 0;
267 	fpnum = FALSE;
268 	if (lastc == '#') {
269 		base = 16;
270 		(*rdf)();
271 	}
272 	if (convdig(lastc) >= MAXBASE)
273 		return (0);
274 	if (lastc == '0')
275 		switch ((*rdf)()) {
276 		case 'x':
277 		case 'X':
278 			base = 16;
279 			(*rdf)();
280 			break;
281 
282 		case 't':
283 		case 'T':
284 			base = 10;
285 			(*rdf)();
286 			break;
287 
288 		case 'o':
289 		case 'O':
290 			base = 8;
291 			(*rdf)();
292 			break;
293 		default:
294 			if (base == 0)
295 				base = 8;
296 			break;
297 		}
298 	if (base == 0)
299 		base = 10;
300 	expv = 0;
301 	for (cp = num, *cp = lastc; ;(*rdf)()) {
302 		if ((d = convdig(lastc)) < base) {
303 			expv *= base;
304 			expv += d;
305 			*cp++ = lastc;
306 		}
307 		else if (lastc == '.') {
308 			fpnum = TRUE;
309 			*cp++ = lastc;
310 		} else {
311 			reread();
312 			break;
313 		}
314 	}
315 	if (fpnum)
316 		expv = fpin(num);
317 	return (1);
318 }
319 
320 void
321 readsym(char *isymbol)
322 {
323 	char	*p;
324 	Rune r;
325 
326 	p = isymbol;
327 	do {
328 		if (p < &isymbol[MAXSYM-UTFmax-1]){
329 			r = lastc;
330 			p += runetochar(p, &r);
331 		}
332 		readchar();
333 	} while (symchar(1));
334 	*p = 0;
335 }
336 
337 void
338 readfname(char *filename)
339 {
340 	char	*p;
341 	Rune	c;
342 
343 	/* snarf chars until un-escaped char in terminal char set */
344 	p = filename;
345 	do {
346 		if ((c = lastc) != '\\' && p < &filename[MAXSYM-UTFmax-1])
347 			p += runetochar(p, &c);
348 		readchar();
349 	} while (c == '\\' || strchr(CMD_VERBS, lastc) == 0);
350 	*p = 0;
351 	reread();
352 }
353 
354 int
355 convdig(int c)
356 {
357 	if (isdigit(c))
358 		return(c-'0');
359 	else if (!isxdigit(c))
360 		return(MAXBASE);
361 	else if (isupper(c))
362 		return(c-'A'+10);
363 	else
364 		return(c-'a'+10);
365 }
366 
367 int
368 symchar(int dig)
369 {
370 	if (lastc=='\\') {
371 		readchar();
372 		return(TRUE);
373 	}
374 	return(isalpha(lastc) || lastc>0x80 || lastc=='_' || dig && isdigit(lastc));
375 }
376 
377 static long
378 dbround(long a, long b)
379 {
380 	long w;
381 
382 	w = (a/b)*b;
383 	if (a!=w)
384 		w += b;
385 	return(w);
386 }
387 
388 ulong
389 dbrget(Map *map, char *name)
390 {
391 	u64int u;
392 
393 	USED(map);
394 	if(rget(correg, name, &u) < 0)
395 		return ~(ulong)0;
396 	return u;
397 }