1 a84cbb2a 2004-04-19 devnull /*
  2 a84cbb2a 2004-04-19 devnull  * Dwarf abbreviation parsing code.
  3 a84cbb2a 2004-04-19 devnull  *
  4 a84cbb2a 2004-04-19 devnull  * The convention here is that calling dwarfgetabbrevs relinquishes
  5 fa325e9b 2020-01-10 cross  * access to any abbrevs returned previously.  Will have to add
  6 a84cbb2a 2004-04-19 devnull  * explicit reference counting if this turns out not to be acceptable.
  7 a84cbb2a 2004-04-19 devnull  */
  8 a84cbb2a 2004-04-19 devnull 
  9 a84cbb2a 2004-04-19 devnull #include <u.h>
 10 a84cbb2a 2004-04-19 devnull #include <libc.h>
 11 a84cbb2a 2004-04-19 devnull #include <bio.h>
 12 a84cbb2a 2004-04-19 devnull #include "elf.h"
 13 a84cbb2a 2004-04-19 devnull #include "dwarf.h"
 14 a84cbb2a 2004-04-19 devnull 
 15 a84cbb2a 2004-04-19 devnull static int parseabbrevs(Dwarf*, ulong, DwarfAbbrev*, DwarfAttr*, int*, int*);
 16 a84cbb2a 2004-04-19 devnull DwarfAbbrev *dwarfgetabbrev(Dwarf*, ulong, ulong);
 17 a84cbb2a 2004-04-19 devnull 
 18 a84cbb2a 2004-04-19 devnull static int
 19 a84cbb2a 2004-04-19 devnull loadabbrevs(Dwarf *d, ulong off, DwarfAbbrev **aa)
 20 a84cbb2a 2004-04-19 devnull {
 21 a84cbb2a 2004-04-19 devnull 	int nattr, nabbrev;
 22 a84cbb2a 2004-04-19 devnull 	DwarfAbbrev *abbrev;
 23 a84cbb2a 2004-04-19 devnull 	DwarfAttr *attr;
 24 a84cbb2a 2004-04-19 devnull 
 25 a84cbb2a 2004-04-19 devnull 	if(d->acache.off == off && d->acache.na){
 26 a84cbb2a 2004-04-19 devnull 		*aa = d->acache.a;
 27 a84cbb2a 2004-04-19 devnull 		return d->acache.na;
 28 a84cbb2a 2004-04-19 devnull 	}
 29 a84cbb2a 2004-04-19 devnull 
 30 a84cbb2a 2004-04-19 devnull 	/* two passes - once to count, then allocate, then a second to copy */
 31 a84cbb2a 2004-04-19 devnull 	if(parseabbrevs(d, off, nil, nil, &nabbrev, &nattr) < 0)
 32 a84cbb2a 2004-04-19 devnull 		return -1;
 33 a84cbb2a 2004-04-19 devnull 
 34 a84cbb2a 2004-04-19 devnull 	abbrev = malloc(nabbrev*sizeof(DwarfAbbrev) + nattr*sizeof(DwarfAttr));
 35 a84cbb2a 2004-04-19 devnull 	attr = (DwarfAttr*)(abbrev+nabbrev);
 36 a84cbb2a 2004-04-19 devnull 
 37 a84cbb2a 2004-04-19 devnull 	if(parseabbrevs(d, off, abbrev, attr, nil, nil) < 0){
 38 a84cbb2a 2004-04-19 devnull 		free(abbrev);
 39 a84cbb2a 2004-04-19 devnull 		return -1;
 40 a84cbb2a 2004-04-19 devnull 	}
 41 a84cbb2a 2004-04-19 devnull 
 42 a84cbb2a 2004-04-19 devnull 	free(d->acache.a);
 43 a84cbb2a 2004-04-19 devnull 	d->acache.a = abbrev;
 44 a84cbb2a 2004-04-19 devnull 	d->acache.na = nabbrev;
 45 a84cbb2a 2004-04-19 devnull 	d->acache.off = off;
 46 a84cbb2a 2004-04-19 devnull 
 47 a84cbb2a 2004-04-19 devnull 	*aa = abbrev;
 48 a84cbb2a 2004-04-19 devnull 	return nabbrev;
 49 a84cbb2a 2004-04-19 devnull }
 50 a84cbb2a 2004-04-19 devnull 
 51 a84cbb2a 2004-04-19 devnull static int
 52 a84cbb2a 2004-04-19 devnull parseabbrevs(Dwarf *d, ulong off, DwarfAbbrev *abbrev, DwarfAttr *attr, int *pnabbrev, int *pnattr)
 53 a84cbb2a 2004-04-19 devnull {
 54 a84cbb2a 2004-04-19 devnull 	int i, nabbrev, nattr, haskids;
 55 a84cbb2a 2004-04-19 devnull 	ulong num, tag, name, form;
 56 a84cbb2a 2004-04-19 devnull 	DwarfBuf b;
 57 a84cbb2a 2004-04-19 devnull 
 58 a84cbb2a 2004-04-19 devnull 	if(off >= d->abbrev.len){
 59 a84cbb2a 2004-04-19 devnull 		werrstr("bad abbrev section offset 0x%lux >= 0x%lux\n", off, d->abbrev.len);
 60 a84cbb2a 2004-04-19 devnull 		return -1;
 61 a84cbb2a 2004-04-19 devnull 	}
 62 a84cbb2a 2004-04-19 devnull 
 63 a84cbb2a 2004-04-19 devnull 	memset(&b, 0, sizeof b);
 64 a84cbb2a 2004-04-19 devnull 	b.p = d->abbrev.data + off;
 65 a84cbb2a 2004-04-19 devnull 	b.ep = d->abbrev.data + d->abbrev.len;
 66 a84cbb2a 2004-04-19 devnull 
 67 a84cbb2a 2004-04-19 devnull 	nabbrev = 0;
 68 a84cbb2a 2004-04-19 devnull 	nattr = 0;
 69 a84cbb2a 2004-04-19 devnull 	for(;;){
 70 a84cbb2a 2004-04-19 devnull 		if(b.p == nil){
 71 a84cbb2a 2004-04-19 devnull 			werrstr("malformed abbrev data");
 72 a84cbb2a 2004-04-19 devnull 			return -1;
 73 a84cbb2a 2004-04-19 devnull 		}
 74 a84cbb2a 2004-04-19 devnull 		num = dwarfget128(&b);
 75 a84cbb2a 2004-04-19 devnull 		if(num == 0)
 76 a84cbb2a 2004-04-19 devnull 			break;
 77 a84cbb2a 2004-04-19 devnull 		tag = dwarfget128(&b);
 78 a84cbb2a 2004-04-19 devnull 		haskids = dwarfget1(&b);
 79 a84cbb2a 2004-04-19 devnull 		for(i=0;; i++){
 80 a84cbb2a 2004-04-19 devnull 			name = dwarfget128(&b);
 81 a84cbb2a 2004-04-19 devnull 			form = dwarfget128(&b);
 82 a84cbb2a 2004-04-19 devnull 			if(name == 0 && form == 0)
 83 a84cbb2a 2004-04-19 devnull 				break;
 84 a84cbb2a 2004-04-19 devnull 			if(attr){
 85 a84cbb2a 2004-04-19 devnull 				attr[i].name = name;
 86 a84cbb2a 2004-04-19 devnull 				attr[i].form = form;
 87 a84cbb2a 2004-04-19 devnull 			}
 88 a84cbb2a 2004-04-19 devnull 		}
 89 a84cbb2a 2004-04-19 devnull 		if(abbrev){
 90 a84cbb2a 2004-04-19 devnull 			abbrev->num = num;
 91 a84cbb2a 2004-04-19 devnull 			abbrev->tag = tag;
 92 a84cbb2a 2004-04-19 devnull 			abbrev->haskids = haskids;
 93 a84cbb2a 2004-04-19 devnull 			abbrev->attr = attr;
 94 a84cbb2a 2004-04-19 devnull 			abbrev->nattr = i;
 95 a84cbb2a 2004-04-19 devnull 			abbrev++;
 96 a84cbb2a 2004-04-19 devnull 			attr += i;
 97 a84cbb2a 2004-04-19 devnull 		}
 98 a84cbb2a 2004-04-19 devnull 		nabbrev++;
 99 a84cbb2a 2004-04-19 devnull 		nattr += i;
100 a84cbb2a 2004-04-19 devnull 	}
101 a84cbb2a 2004-04-19 devnull 	if(pnabbrev)
102 a84cbb2a 2004-04-19 devnull 		*pnabbrev = nabbrev;
103 a84cbb2a 2004-04-19 devnull 	if(pnattr)
104 a84cbb2a 2004-04-19 devnull 		*pnattr = nattr;
105 a84cbb2a 2004-04-19 devnull 	return 0;
106 a84cbb2a 2004-04-19 devnull }
107 a84cbb2a 2004-04-19 devnull 
108 a84cbb2a 2004-04-19 devnull static DwarfAbbrev*
109 a84cbb2a 2004-04-19 devnull findabbrev(DwarfAbbrev *a, int na, ulong num)
110 a84cbb2a 2004-04-19 devnull {
111 a84cbb2a 2004-04-19 devnull 	int i;
112 a84cbb2a 2004-04-19 devnull 
113 a84cbb2a 2004-04-19 devnull 	for(i=0; i<na; i++)
114 a84cbb2a 2004-04-19 devnull 		if(a[i].num == num)
115 a84cbb2a 2004-04-19 devnull 			return &a[i];
116 eaf56db5 2004-04-21 devnull 	werrstr("abbrev not found");
117 a84cbb2a 2004-04-19 devnull 	return nil;
118 a84cbb2a 2004-04-19 devnull }
119 a84cbb2a 2004-04-19 devnull 
120 a84cbb2a 2004-04-19 devnull DwarfAbbrev*
121 a84cbb2a 2004-04-19 devnull dwarfgetabbrev(Dwarf *d, ulong off, ulong num)
122 a84cbb2a 2004-04-19 devnull {
123 a84cbb2a 2004-04-19 devnull 	DwarfAbbrev *a;
124 a84cbb2a 2004-04-19 devnull 	int na;
125 a84cbb2a 2004-04-19 devnull 
126 eaf56db5 2004-04-21 devnull 	if((na = loadabbrevs(d, off, &a)) < 0){
127 eaf56db5 2004-04-21 devnull 		werrstr("loadabbrevs: %r");
128 a84cbb2a 2004-04-19 devnull 		return nil;
129 eaf56db5 2004-04-21 devnull 	}
130 a84cbb2a 2004-04-19 devnull 	return findabbrev(a, na, num);
131 a84cbb2a 2004-04-19 devnull }