static int
_dwarfnametounit(Dwarf *d, char *name, DwarfBlock *bl, DwarfSym *s)
{
int vers;
ulong len, unit, off;
uchar *next;
char *str;
DwarfBuf b;
b.d = d;
b.p = bl->data;
b.ep = b.p + bl->len;
while(b.p < b.ep){
len = dwarfget4(&b);
if(len > b.ep-b.p){
werrstr("bad length in dwarf name header");
return -1;
}
next = b.p + len;
vers = dwarfget2(&b);
if(vers != 1 && vers != 2){
werrstr("bad version %d in dwarf name header", vers);
return -1;
}
unit = dwarfget4(&b);
dwarfget4(&b); /* unit length */
while(b.p < next){
off = dwarfget4(&b);
if(off == 0)
break;
str = dwarfgetstring(&b);
if(strcmp(str, name) == 0){
if(dwarfenumunit(d, unit, s) < 0)
return -1;
if(unit + off >= s->b.ep - d->info.data){
werrstr("bad offset in name entry");
return -1;
}
s->b.p = d->info.data + unit + off;
if(dwarfnextsym(d, s) < 0)
return -1;
if(s->attrs.name==nil || strcmp(s->attrs.name, name)!=0){
werrstr("unexpected name %#q in lookup for %#q", s->attrs.name, name);
return -1;
}
return 0;
}
}
b.p = next;
}
werrstr("unknown name '%s'", name);
return -1;
}
int
dwarflookupnameinunit(Dwarf *d, ulong unit, char *name, DwarfSym *s)
{
DwarfSym compunit = { };
if(dwarfenumunit(d, unit, &compunit) < 0)
return -1;
while(dwarfnextsymat(d, &compunit, s) == 0) {
werrstr("got %s looking for %s\n", s->attrs.name, name);
if(s->attrs.name && strcmp(s->attrs.name, name) == 0)
return 0;
}
werrstr("symbol '%s' not found", name);
return -1;
}
int
dwarflookupfn(Dwarf *d, ulong unit, ulong pc, DwarfSym *s)
{
DwarfSym compunit = { };
if(dwarfenumunit(d, unit, &compunit) < 0)
return -1;
while(dwarfnextsymat(d, &compunit, s) == 0){
if(s->attrs.tag != TagSubprogram)
continue;
if(s->attrs.lowpc <= pc && pc < s->attrs.highpc)
return 0;
}
werrstr("fn containing pc 0x%lux not found", pc);
return -1;
}
int
dwarfseeksym(Dwarf *d, ulong unit, ulong off, DwarfSym *s)
{
DwarfSym compunit = { };
if(dwarfenumunit(d, unit, &compunit) < 0)
return -1;
werrstr("dwarfseeksym: unit %x off %x\n", unit, off);
s->b.d = d;
s->b.p = d->info.data + unit + off;
s->b.ep = compunit.b.ep;
if(dwarfnextsymat(d, &compunit, s) == -1)
return -1;
werrstr("dwarfseeksym: unit %x off %x, tag %x", unit, off, s->attrs.tag);
return 0;
}
int
dwarflookuptag(Dwarf *d, ulong unit, ulong tag, DwarfSym *s)
{
DwarfSym compunit = { };
if (dwarfenumunit(d, unit, &compunit) < 0) {
return -1;
}
do {
if (compunit.attrs.tag == tag) {
*s = compunit;
return 0;
}
if (dwarflookupchildtag(d, &compunit, tag, s) == 0)
return 0;
} while(dwarfnextsym(d, &compunit) == 0);
werrstr("symbol with tag 0x%lux not found", tag);
return -1;
}
int
dwarfpctoline(Dwarf *d, DwarfSym *proc, ulong pc, char **file, char **function, ulong *line)
{
char *cdir;
uchar *prog, *opcount, *end, *dirs;
ulong off, unit, len, vers, x, start, lastline;
int i, first, firstline, op, a, l, quantum, isstmt, linebase, linerange, opcodebase, nf;
char *files, *s;
DwarfBuf b;
DwarfSym sym;
State emit, cur, reset;
char **f, **newf;
f = nil;
memset(proc, 0, sizeof(*proc));
int runit = dwarfaddrtounit(d, pc, &unit);
if (runit < 0)
return -1;
int rtag = dwarflookuptag(d, unit, TagCompileUnit, &sym);
if (rtag < 0)
return -1;
if(!sym.attrs.have.stmtlist){
werrstr("no line mapping information for 0x%x", pc);
return -1;
}
off = sym.attrs.stmtlist;
if(off >= d->line.len){
werrstr("bad stmtlist");
goto bad;
}
if(trace) werrstr("unit 0x%x stmtlist 0x%x", unit, sym.attrs.stmtlist);
memset(&b, 0, sizeof b);
b.d = d;
b.p = d->line.data + off;
b.ep = b.p + d->line.len;
b.addrsize = sym.b.addrsize; /* should i get this from somewhere else? */
len = dwarfget4(&b);
if(b.p==nil || b.p+len > b.ep || b.p+len < b.p){
werrstr("bad len");
goto bad;
}
b.ep = b.p+len;
vers = dwarfget2(&b);
if(vers != 2){
werrstr("bad dwarf version 0x%x", vers);
return -1;
}
len = dwarfget4(&b);
if(b.p==nil || b.p+len > b.ep || b.p+len < b.p){
werrstr("another bad len");
goto bad;
}
prog = b.p+len;
quantum = dwarfget1(&b);
isstmt = dwarfget1(&b);
linebase = (schar)dwarfget1(&b);
linerange = (schar)dwarfget1(&b);
opcodebase = dwarfget1(&b);
opcount = b.p-1;
dwarfgetnref(&b, opcodebase-1);
if(b.p == nil){
werrstr("bad opcode chart");
goto bad;
}
/* just skip the files and dirs for now; we'll come back */
dirs = b.p;
while (b.p && *b.p)
dwarfgetstring(&b);
dwarfget1(&b);
files = (char*)b.p;
while(b.p!=nil && *b.p!=0){
dwarfgetstring(&b);
dwarfget128(&b);
dwarfget128(&b);
dwarfget128(&b);
}
dwarfget1(&b);
/* move on to the program */
if(b.p == nil || b.p > prog){
werrstr("bad header");
goto bad;
}
b.p = prog;
reset.addr = 0;
reset.file = 1;
reset.line = 1;
reset.column = 0;
reset.flags = isstmt ? Isstmt : 0;
reset.isa = 0;
cur = reset;
emit = reset;
nf = 0;
start = 0;
if(trace) werrstr("program @ %lu ... %.*H opbase = %d", b.p - d->line.data, b.ep-b.p, b.p, opcodebase);
first = 1;
while(b.p != nil){
firstline = 0;
op = dwarfget1(&b);
if(trace) werrstr("\tline %lu, addr 0x%x, op %d %.10H", cur.line, cur.addr, op, b.p);
if(op >= opcodebase){
a = (op - opcodebase) / linerange;
l = (op - opcodebase) % linerange + linebase;
cur.line += l;
cur.addr += a * quantum;
if(trace) werrstr(" +%d,%d", a, l);
emit:
if(first){
if(cur.addr > pc){
werrstr("found wrong line mapping 0x%x for pc 0x%x", cur.addr, pc);
/* This is an overzealous check. gcc can produce discontiguous ranges
and reorder statements, so it's possible for a future line to start
ahead of pc and still find a matching one. */
/*goto out;*/
firstline = 1;
}
first = 0;
start = cur.addr;
}
if(cur.addr > pc && !firstline)
break;
if(b.p == nil){
werrstr("buffer underflow in line mapping");
goto out;
}
emit = cur;
if(emit.flags & EndSequence){
werrstr("found wrong line mapping 0x%x-0x%x for pc 0x%x", start, cur.addr, pc);
goto out;
}
cur.flags &= ~(BasicDwarfBlock|PrologueEnd|EpilogueBegin);
}else{
switch(op){
case 0: /* extended op code */
if(trace) werrstr(" ext");
len = dwarfget128(&b);
end = b.p+len;
if(b.p == nil || end > b.ep || end < b.p || len < 1)
goto bad;
switch(dwarfget1(&b)){
case 1: /* end sequence */
if(trace) werrstr(" end");
cur.flags |= EndSequence;
goto emit;
case 2: /* set address */
cur.addr = dwarfgetaddr(&b);
if(trace) werrstr(" set pc 0x%x", cur.addr);
break;
case 3: /* define file */
newf = malloc(nf+1*sizeof(f[0]));
if (newf)
RtlMoveMemory(newf, f, nf*sizeof(f[0]));
if(newf == nil)
goto out;
free(f);
f = newf;
f[nf++] = s = dwarfgetstring(&b);
DPRINT1("str %s", s);
dwarfget128(&b);
dwarfget128(&b);
dwarfget128(&b);
if(trace) werrstr(" def file %s", s);
break;
}
if(b.p == nil || b.p > end)
goto bad;
b.p = end;
break;
case 1: /* emit */
if(trace) werrstr(" emit");
goto emit;
case 2: /* advance pc */
a = dwarfget128(&b);
if(trace) werrstr(" advance pc + %lu", a*quantum);
cur.addr += a * quantum;
break;
case 3: /* advance line */
l = dwarfget128s(&b);
if(trace) werrstr(" advance line + %ld", l);
cur.line += l;
break;
case 4: /* set file */
if(trace) werrstr(" set file");
cur.file = dwarfget128s(&b);
break;
case 5: /* set column */
if(trace) werrstr(" set column");
cur.column = dwarfget128(&b);
break;
case 6: /* negate stmt */
if(trace) werrstr(" negate stmt");
cur.flags ^= Isstmt;
break;
case 7: /* set basic block */
if(trace) werrstr(" set basic block");
cur.flags |= BasicDwarfBlock;
break;
case 8: /* const add pc */
a = (255 - opcodebase) / linerange * quantum;
if(trace) werrstr(" const add pc + %d", a);
cur.addr += a;
break;
case 9: /* fixed advance pc */
a = dwarfget2(&b);
if(trace) werrstr(" fixed advance pc + %d", a);
cur.addr += a;
break;
case 10: /* set prologue end */
if(trace) werrstr(" set prologue end");
cur.flags |= PrologueEnd;
break;
case 11: /* set epilogue begin */
if(trace) werrstr(" set epilogue begin");
cur.flags |= EpilogueBegin;
break;
case 12: /* set isa */
if(trace) werrstr(" set isa");
cur.isa = dwarfget128(&b);
break;
default: /* something new - skip it */
if(trace) werrstr(" unknown %d", opcount[op]);
for(i=0; i<opcount[op]; i++)
dwarfget128(&b);
break;
}
}
}
if(b.p == nil)
goto bad;
/* finally! the data we seek is in "emit" */
if(emit.file == 0){
werrstr("invalid file index in mapping data");
goto out;
}
if(line)
*line = emit.line;
/* skip over first emit.file-2 guys */
b.p = (uchar*)files;
for(i=emit.file-1; i > 0 && b.p!=nil && *b.p!=0; i--){
dwarfgetstring(&b);
dwarfget128(&b);
dwarfget128(&b);
dwarfget128(&b);
}
if(b.p == nil){
werrstr("problem parsing file data second time (cannot happen)");
goto bad;
}
if(*b.p == 0){
if(i >= nf){
werrstr("bad file index in mapping data");
goto bad;
}
b.p = (uchar*)f[i];
}
s = dwarfgetstring(&b);
*file = s;
i = dwarfget128(&b); /* directory */
x = dwarfget128(&b);
x = dwarfget128(&b);
/* fetch dir name */
cdir = sym.attrs.have.compdir ? sym.attrs.compdir : 0;
char *dwarfdir;
dwarfdir = nil;
b.p = dirs;
for (x = 1; b.p && *b.p; x++) {
dwarfdir = dwarfgetstring(&b);
if (x == i) break;
}
if (!cdir && dwarfdir)
cdir = dwarfdir;
char *filefull = malloc(strlen(cdir) + strlen(*file) + 2);
strcpy(filefull, cdir);
strcat(filefull, "/");
strcat(filefull, *file);
*file = filefull;
*function = nil;
lastline = 0;
runit = dwarfaddrtounit(d, pc, &unit);
if (runit == 0) {
DwarfSym compunit = { };
int renum = dwarfenumunit(d, unit, &compunit);
if (renum < 0)
return -1;
renum = dwarfnextsymat(d, &compunit, proc);
while (renum == 0) {
if (proc->attrs.tag == TagSubprogram &&
proc->attrs.have.name)
{
if (proc->attrs.lowpc <= pc && proc->attrs.highpc > pc) {
*function = malloc(strlen(proc->attrs.name)+1);
strcpy(*function, proc->attrs.name);
goto done;
}
}
renum = dwarfnextsym(d, proc);
}
}
// Next search by declaration
runit = dwarfaddrtounit(d, pc, &unit);
if (runit == 0) {
DwarfSym compunit = { };
int renum = dwarfenumunit(d, unit, &compunit);
if (renum < 0)
return -1;
renum = dwarfnextsymat(d, &compunit, proc);
while (renum == 0) {
if (proc->attrs.tag == TagSubprogram &&
proc->attrs.have.name &&
proc->attrs.declfile == emit.file)
{
if (proc->attrs.declline <= *line &&
proc->attrs.declline > lastline) {
free(*function);
*function = malloc(strlen(proc->attrs.name)+1);
strcpy(*function, proc->attrs.name);
goto done;
}
lastline = proc->attrs.declline;
}
renum = dwarfnextsym(d, proc);
}
}
/* free at last, free at last */
done:
free(f);
return 0;
bad:
werrstr("corrupted line mapping for 0x%x", pc);
out:
free(f);
return -1;
}