di._structs = { }
di._saved_errno = None
di._result_stream = os.fdopen(3, 'w')
+ di._errno_workaround = None
# assembling structs
# sigh, we have to record the order of the arguments!
fields = di._find_fields(typename)
return fields.substitute(values)
+ # hideous workaround
+
+ def _parse_eval_errno(di, expr_pat):
+ # evaluates expr_pat % 'errno'
+ if di._errno_workaround is not True:
+ try:
+ x = parse_eval(expr_pat % 'errno')
+ di._errno_workaround = False
+ return x
+ except gdb.error as e:
+ if di._errno_workaround is False:
+ raise e
+ di._errno_workaround = True
+ # Incomprehensibly, gdb.parse_and_eval('errno') can sometimes
+ # fail with
+ # gdb.error: Cannot find thread-local variables on this target
+ # even though plain gdb `print errno' works while `print errno = 25'
+ # doesn't. OMG. This may be related to:
+ # https://github.com/cloudburst/libheap/issues/24
+ # although I can't find it in the gdb bug db (which is half-broken
+ # in my browser). Also the error is very nonspecific :-/.
+ # This seems to happen on jessie, and is fixed in stretch.
+ # Anyway:
+ return parse_eval(expr_pat % '(*((int (*)(void))__errno_location)())')
+
# calling functions (need to cast the function name to the right
# type in case maybe gdb doesn't know the type)
def _must_func(di, functype, funcname, realargs):
retval = di._func(functype, funcname, realargs)
if retval < 0:
- errnoval = parse_eval('errno')
+ errnoval = di._parse_eval_errno('%s')
raise RuntimeError("%s gave errno=%d `%s'" %
(funcname, errnoval, os.strerror(errnoval)))
return retval
'("%s", %d)' % (_string_escape_for_c(path), mode)
)
if r < 0:
- errnoval = parse_eval('errno')
+ errnoval = di._parse_eval_errno('%s')
if errnoval != os.errno.EEXIST:
raise RuntimeError("mkdir %s failed: `%s'" %
(repr(path), os.strerror(errnoval)))
return 1
def _errno_save(di):
- di._saved_errno = parse_eval('errno')
+ di._saved_errno = di._parse_eval_errno('%s')
def _errno_restore(di):
to_restore = di._saved_errno
di._saved_errno = None
if to_restore is not None:
- parse_eval('errno = %d' % to_restore)
+ di._parse_eval_errno('%%s = %d' % to_restore)
def _result(di, output):
sys.stderr.write("#> %s" % output)