support break function with file prefix

Author: cocolato

Lib/pdb.py

@@ -1337,7 +1337,7 @@ def do_commands(self, arg):
     complete_commands = _complete_bpnumber
 
     def do_break(self, arg, temporary=False):
-        """b(reak) [ ([filename:]lineno | function) [, condition] ]
+        """b(reak) [ [filename:](lineno | function) [, condition] ]
 
         Without argument, list all breaks.
 
@@ -1347,9 +1347,9 @@ def do_break(self, arg, temporary=False):
         present, it is a string specifying an expression which must
         evaluate to true before the breakpoint is honored.
 
-        The line number may be prefixed with a filename and a colon,
-        to specify a breakpoint in another file (probably one that
-        hasn't been loaded yet).  The file is searched for on
+        The line number and function may be prefixed with a filename and
+        a colon, to specify a breakpoint in another file (probably one
+        that hasn't been loaded yet).  The file is searched for on
         sys.path; the .py suffix may be omitted.
         """
         if not arg:
@@ -1388,8 +1388,13 @@ def do_break(self, arg, temporary=False):
             try:
                 lineno = int(arg)
             except ValueError:
-                self.error('Bad lineno: %s' % arg)
-                return
+                func = arg
+                ok, filename, ln = find_function(func, self.canonic(filename))
+                if not ok:
+                    self.error('Bad lineno or function name: %s' % arg)
+                    return
+                funcname = ok
+                lineno = int(ln)
         else:
             # no colon; can be lineno or function
             try:

Lib/test/test_pdb.py

@@ -4622,6 +4622,18 @@ def foo(self):
         stdout, stderr = self.run_pdb_script(script, commands)
         self.assertIn("The specified object 'C.foo' is not a function", stdout)
 
+    def test_break_function_with_file(self):
+        script = """
+            def foo():
+                pass
+        """
+        commands = """
+            break main:foo
+            quit
+        """
+        stdout, stderr = self.run_pdb_script(script, commands)
+        self.assertRegex(stdout, r"Breakpoint 1 at .*main\.py:3")
+
 
 class ChecklineTests(unittest.TestCase):
     def setUp(self):