1 #include <u.h>
2 #include <libc.h>
3 #include <bio.h>
4 #include <mach.h>
5 
6 /*
7  * XXX could remove the rock by hiding it in a special regs.
8  * That would still be sleazy but would be thread-safe.
9  */
10 
11 static struct {
12 	int found;
13 	int nframe;
14 	Loc l;
15 	char *fn;
16 	char *var;
17 } rock;
18 
19 static int
20 ltrace(Map *map, Regs *regs, ulong pc, ulong nextpc, Symbol *sym, int depth)
21 {
22 	ulong v;
23 	Symbol s1;
24 
25 	USED(pc);
26 	USED(nextpc);
27 	USED(depth);
28 
29 	if(sym==nil || strcmp(sym->name, rock.fn) != 0)
30 		return ++rock.nframe < 40;
31 	if(lookuplsym(sym, rock.var, &s1) < 0)
32 		return 0;
33 	if(locsimplify(map, regs, s1.loc, &rock.l) < 0)
34 		return 0;
35 	if(rock.l.type == LREG && rget(regs, rock.l.reg, &v) >= 0)
36 		rock.l = locconst(v);
37 	if(rock.l.type != LADDR && rock.l.type != LCONST)
38 		return 0;
39 	rock.found = 1;
40 	return 0;
41 }
42 
43 int
44 localaddr(Map *map, Regs *regs, char *fn, char *var, ulong *val)
45 {
46 	rock.found = 0;
47 	rock.nframe = 0;
48 	rock.fn = fn;
49 	rock.var = var;
50 	stacktrace(map, regs, ltrace);
51 	if(rock.found){
52 		*val = rock.l.addr;
53 		return 0;
54 	}
55 	return -1;
56 }