1 /*
2 * obj.c
3 * routines universal to all object files
4 */
5 #include <u.h>
6 #include <libc.h>
7 #include <bio.h>
8 #include <ar.h>
9 #include <mach.h>
10 #include "obj.h"
11
12 #define islocal(t) ((t)=='a' || (t)=='p')
13
14 enum
15 {
16 NNAMES = 50,
17 MAXIS = 8, /* max length to determine if a file is a .? file */
18 MAXOFF = 0x7fffffff, /* larger than any possible local offset */
19 NHASH = 1024, /* must be power of two */
20 HASHMUL = 79L,
21 };
22
23 int _is2(char*), /* in [$OS].c */
24 _is5(char*),
25 _is6(char*),
26 _is7(char*),
27 _is8(char*),
28 _is9(char*),
29 _isk(char*),
30 _isq(char*),
31 _isv(char*),
32 _isu(char*),
33 _read2(Biobuf*, Prog*),
34 _read5(Biobuf*, Prog*),
35 _read6(Biobuf*, Prog*),
36 _read7(Biobuf*, Prog*),
37 _read8(Biobuf*, Prog*),
38 _read9(Biobuf*, Prog*),
39 _readk(Biobuf*, Prog*),
40 _readq(Biobuf*, Prog*),
41 _readv(Biobuf*, Prog*),
42 _readu(Biobuf*, Prog*);
43
44 typedef struct Obj Obj;
45 typedef struct Symtab Symtab;
46
47 struct Obj /* functions to handle each intermediate (.$O) file */
48 {
49 char *name; /* name of each $O file */
50 int (*is)(char*); /* test for each type of $O file */
51 int (*read)(Biobuf*, Prog*); /* read for each type of $O file*/
52 };
53
54 static Obj obj[] =
55 { /* functions to identify and parse each type of obj */
56 [Obj68020] "68020 .2", _is2, _read2,
57 [ObjAmd64] "amd64 .6", _is6, _read6,
58 [ObjArm] "arm .5", _is5, _read5,
59 [ObjAlpha] "alpha .7", _is7, _read7,
60 [Obj386] "386 .8", _is8, _read8,
61 [ObjSparc] "sparc .k", _isk, _readk,
62 [ObjPower] "power .q", _isq, _readq,
63 [ObjMips] "mips .v", _isv, _readv,
64 [ObjSparc64] "sparc64 .u", _isu, _readu,
65 [ObjPower64] "power64 .9", _is9, _read9,
66 [Maxobjtype] 0, 0
67 };
68
69 struct Symtab
70 {
71 struct Sym s;
72 struct Symtab *next;
73 };
74
75 static Symtab *hash[NHASH];
76 static Sym *names[NNAMES]; /* working set of active names */
77
78 static int processprog(Prog*,int); /* decode each symbol reference */
79 static void objreset(void);
80 static void objlookup(int, char *, int, uint);
81 static void objupdate(int, int);
82
83 int
objtype(Biobuf * bp,char ** name)84 objtype(Biobuf *bp, char **name)
85 {
86 int i;
87 char buf[MAXIS];
88
89 if(Bread(bp, buf, MAXIS) < MAXIS)
90 return -1;
91 Bseek(bp, -MAXIS, 1);
92 for (i = 0; i < Maxobjtype; i++) {
93 if (obj[i].is && (*obj[i].is)(buf)) {
94 if (name)
95 *name = obj[i].name;
96 return i;
97 }
98 }
99 return -1;
100 }
101
102 int
isar(Biobuf * bp)103 isar(Biobuf *bp)
104 {
105 int n;
106 char magbuf[SARMAG];
107
108 n = Bread(bp, magbuf, SARMAG);
109 if(n == SARMAG && strncmp(magbuf, ARMAG, SARMAG) == 0)
110 return 1;
111 return 0;
112 }
113
114 /*
115 * determine what kind of object file this is and process it.
116 * return whether or not this was a recognized intermediate file.
117 */
118 int
readobj(Biobuf * bp,int objtype)119 readobj(Biobuf *bp, int objtype)
120 {
121 Prog p;
122
123 if (objtype < 0 || objtype >= Maxobjtype || obj[objtype].is == 0)
124 return 1;
125 objreset();
126 while ((*obj[objtype].read)(bp, &p))
127 if (!processprog(&p, 1))
128 return 0;
129 return 1;
130 }
131
132 int
readar(Biobuf * bp,int objtype,vlong end,int doautos)133 readar(Biobuf *bp, int objtype, vlong end, int doautos)
134 {
135 Prog p;
136
137 if (objtype < 0 || objtype >= Maxobjtype || obj[objtype].is == 0)
138 return 1;
139 objreset();
140 while ((*obj[objtype].read)(bp, &p) && Boffset(bp) < end)
141 if (!processprog(&p, doautos))
142 return 0;
143 return 1;
144 }
145
146 /*
147 * decode a symbol reference or definition
148 */
149 static int
processprog(Prog * p,int doautos)150 processprog(Prog *p, int doautos)
151 {
152 if(p->kind == aNone)
153 return 1;
154 if(p->sym < 0 || p->sym >= NNAMES)
155 return 0;
156 switch(p->kind)
157 {
158 case aName:
159 if (!doautos)
160 if(p->type != 'U' && p->type != 'b')
161 break;
162 objlookup(p->sym, p->id, p->type, p->sig);
163 break;
164 case aText:
165 objupdate(p->sym, 'T');
166 break;
167 case aData:
168 objupdate(p->sym, 'D');
169 break;
170 default:
171 break;
172 }
173 return 1;
174 }
175
176 /*
177 * find the entry for s in the symbol array.
178 * make a new entry if it is not already there.
179 */
180 static void
objlookup(int id,char * name,int type,uint sig)181 objlookup(int id, char *name, int type, uint sig)
182 {
183 long h;
184 char *cp;
185 Sym *s;
186 Symtab *sp;
187
188 s = names[id];
189 if(s && strcmp(s->name, name) == 0) {
190 s->type = type;
191 s->sig = sig;
192 return;
193 }
194
195 h = *name;
196 for(cp = name+1; *cp; h += *cp++)
197 h *= HASHMUL;
198 if(h < 0)
199 h = ~h;
200 h &= (NHASH-1);
201 if (type == 'U' || type == 'b' || islocal(type)) {
202 for(sp = hash[h]; sp; sp = sp->next)
203 if(strcmp(sp->s.name, name) == 0) {
204 switch(sp->s.type) {
205 case 'T':
206 case 'D':
207 case 'U':
208 if (type == 'U') {
209 names[id] = &sp->s;
210 return;
211 }
212 break;
213 case 't':
214 case 'd':
215 case 'b':
216 if (type == 'b') {
217 names[id] = &sp->s;
218 return;
219 }
220 break;
221 case 'a':
222 case 'p':
223 if (islocal(type)) {
224 names[id] = &sp->s;
225 return;
226 }
227 break;
228 default:
229 break;
230 }
231 }
232 }
233 sp = malloc(sizeof(Symtab));
234 sp->s.name = name;
235 sp->s.type = type;
236 sp->s.sig = sig;
237 sp->s.value = islocal(type) ? MAXOFF : 0;
238 names[id] = &sp->s;
239 sp->next = hash[h];
240 hash[h] = sp;
241 return;
242 }
243 /*
244 * traverse the symbol lists
245 */
246 void
objtraverse(void (* fn)(Sym *,void *),void * pointer)247 objtraverse(void (*fn)(Sym*, void*), void *pointer)
248 {
249 int i;
250 Symtab *s;
251
252 for(i = 0; i < NHASH; i++)
253 for(s = hash[i]; s; s = s->next)
254 (*fn)(&s->s, pointer);
255 }
256
257 /*
258 * update the offset information for a 'a' or 'p' symbol in an intermediate file
259 */
260 void
_offset(int id,vlong off)261 _offset(int id, vlong off)
262 {
263 Sym *s;
264
265 s = names[id];
266 if (s && s->name[0] && islocal(s->type) && s->value > off)
267 s->value = off;
268 }
269
270 /*
271 * update the type of a global text or data symbol
272 */
273 static void
objupdate(int id,int type)274 objupdate(int id, int type)
275 {
276 Sym *s;
277
278 s = names[id];
279 if (s && s->name[0])
280 if (s->type == 'U')
281 s->type = type;
282 else if (s->type == 'b')
283 s->type = tolower(type);
284 }
285
286 /*
287 * look for the next file in an archive
288 */
289 int
nextar(Biobuf * bp,int offset,char * buf)290 nextar(Biobuf *bp, int offset, char *buf)
291 {
292 struct ar_hdr a;
293 int i, r;
294 long arsize;
295
296 if (offset&01)
297 offset++;
298 Bseek(bp, offset, 0);
299 r = Bread(bp, &a, SAR_HDR);
300 if(r != SAR_HDR)
301 return 0;
302 if(strncmp(a.fmag, ARFMAG, sizeof(a.fmag)))
303 return -1;
304 for(i=0; i<sizeof(a.name) && i<SARNAME && a.name[i] != ' '; i++)
305 buf[i] = a.name[i];
306 buf[i] = 0;
307 arsize = strtol(a.size, 0, 0);
308 if (arsize&1)
309 arsize++;
310 return arsize + SAR_HDR;
311 }
312
313 static void
objreset(void)314 objreset(void)
315 {
316 int i;
317 Symtab *s, *n;
318
319 for(i = 0; i < NHASH; i++) {
320 for(s = hash[i]; s; s = n) {
321 n = s->next;
322 free(s->s.name);
323 free(s);
324 }
325 hash[i] = 0;
326 }
327 memset(names, 0, sizeof names);
328 }
329