introduce "throw_if_false" function

sphinxcontrib/phpdomain.py

@@ -37,6 +37,15 @@ def log_warning(fromdocnode, message: str):
     logger.warning(f"[phpdomain] {message}", location=fromdocnode, type="phpdomain")
 
 
+def throw_if_false(fromdocnode, value, message: str):
+    """
+    Log warning if the value is not true and throw ValueError. Should set exit code to non-zero.
+    """
+    if not value:
+        log_warning(fromdocnode, message)
+        raise ValueError
+
+
 php_sig_re = re.compile(
     r"""
     ^
@@ -205,8 +214,7 @@ def handle_signature(self, sig, signode):
         """
         m = php_sig_re.match(sig)
         if m is None:
-            log_warning(signode, "Invalid signature: " + sig)
-            raise ValueError
+            throw_if_false(signode, False, "Invalid signature")
 
         visibility, modifiers, name_prefix, name, arglist, retann, enumtype = m.groups()