argdist, trace: Support non-C identifier names

When argdist or trace face a function that has characters
in its name that are not valid in C identifier, they now
replace these characters with an underscore (`_`) when
generating function names and structure names to include
in the BPF program. As a result, it is now possible to
trace functions that have these identifiers in their names,
such as Golang functions like `fmt.Println`.

tools/argdist.py

@@ -159,7 +159,7 @@ def _validate_specifier(self):
  if parts[0] not in ["r", "p", "t", "u"]:
  self._bail("probe type must be 'p', 'r', 't', or 'u'" +
  " but got '%s'" % parts[0])
- if re.match(r"\w+\(.*\)", parts[2]) is None:
+ if re.match(r"\S+\(.*\)", parts[2]) is None:
  self._bail(("function signature '%s' has an invalid " +
  "format") % parts[2])
 
@@ -173,6 +173,9 @@ def _parse_exprs(self, exprs):
  self._bail("no exprs specified")
  self.exprs = exprs.split(',')
 
+ def _make_valid_identifier(self, ident):
+ return re.sub(r'[^A-Za-z0-9_]', '_', ident)
+
  def __init__(self, tool, type, specifier):
  self.usdt_ctx = None
  self.streq_functions = ""
@@ -196,8 +199,9 @@ def __init__(self, tool, type, specifier):
  self.tp_event = self.function
  elif self.probe_type == "u":
  self.library = parts[1]
- self.probe_func_name = "%s_probe%d" % \
- (self.function, Probe.next_probe_index)
+ self.probe_func_name = self._make_valid_identifier(
+ "%s_probe%d" % \
+ (self.function, Probe.next_probe_index))
  self._enable_usdt_probe()
  else:
  self.library = parts[1]
@@ -233,10 +237,12 @@ def check(expr):
  self.entry_probe_required = self.probe_type == "r" and \
  (any(map(check, self.exprs)) or check(self.filter))
 
- self.probe_func_name = "%s_probe%d" % \
- (self.function, Probe.next_probe_index)
- self.probe_hash_name = "%s_hash%d" % \
- (self.function, Probe.next_probe_index)
+ self.probe_func_name = self._make_valid_identifier(
+ "%s_probe%d" % \
+ (self.function, Probe.next_probe_index))
+ self.probe_hash_name = self._make_valid_identifier(
+ "%s_hash%d" % \
+ (self.function, Probe.next_probe_index))
  Probe.next_probe_index += 1
 
  def _enable_usdt_probe(self):

tools/trace.py

@@ -76,8 +76,7 @@ def __init__(self, probe, string_size, kernel_stack, user_stack):
  self.probe_num = Probe.probe_count
  self.probe_name = "probe_%s_%d" % \
  (self._display_function(), self.probe_num)
- if self.probe_name.find(".") > 0: # for golang
- self.probe_name = self.probe_name.replace(".", "_DOT_")
+ self.probe_name = re.sub(r'[^A-Za-z0-9_]', '_', self.probe_name)
 
  def __str__(self):
  return "%s:%s:%s FLT=%s ACT=%s/%s" % (self.probe_type,