bash: function calls detect

Hi, is it possible to implement function calls detection for shell scripts? (e.g., highlight them).
I use Pygments as GNU GLOBAL source code tagging system plug-in parser, and this functionality would greatly improve usability of the project, allowing references to function calls, not only definitions.

When the name of a shell function is used as a simple command name, the list of commands associated with that function name is executed.

So can we just catch all the simple commands?

@thatch @Tim Hatch @Georg Brandl

I applied following hack to overcome the problem:

--- pygments/lexers/shell.py~   2017-01-23 00:01:32.000000000 +0300
+++ /usr/lib64/python2.7/site-packages/pygments/lexers/shell.py 2019-01-20 01:56:56.724115547 +0300
@@ -85,7 +85,7 @@
             (r'\|', Punctuation),
             (r'\s+', Text),
             (r'\d+\b', Number),
-            (r'[^=\s\[\]{}()$"\'`\\<&|;]+', Text),
+            (r'[^=\s\[\]{}()$"\'`\\<&|;]+', Name.Function),
             (r'<', Text),
         ],
         'string': [

Now make test can't pass:

======================================================================
FAIL: testNeedsName (test_shell.BashSessionTest)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/home/bam/test/pygments/tests/test_shell.py", line 141, in testNeedsName
    self.assertEqual(tokens, list(self.lexer.get_tokens(fragment)))
AssertionError: Lists differ: [(Token.Text, u''), (Token.Gen... != [(Token.Text, u''), (Token.Gen...

First differing element 6:
(Token.Text, u'hi')
(Token.Name.Function, u'hi')

  [(Token.Text, u''),
   (Token.Generic.Prompt, u'$'),
   (Token.Text, u' '),
   (Token.Name.Builtin, u'echo'),
   (Token.Text, u' '),
   (Token.Literal.String.Escape, u'\\\n'),
-  (Token.Text, u'hi'),
+  (Token.Name.Function, u'hi'),
   (Token.Text, u'\n'),
   (Token.Generic.Output, u'hi\n')]
    """Fail immediately, with the given message."""
>>  raise self.failureException("Lists differ: [(Token.Text, u''), (Token.Gen... != [(Token.Text, u''), (Token.Gen...\n\nFirst differing element 6:\n(Token.Text, u'hi')\n(Token.Name.Function, u'hi')\n\n  [(Token.Text, u''),\n   (Token.Generic.Prompt, u'$'),\n   (Token.Text, u' '),\n   (Token.Name.Builtin, u'echo'),\n   (Token.Text, u' '),\n   (Token.Literal.String.Escape, u'\\\\\\n'),\n-  (Token.Text, u'hi'),\n+  (Token.Name.Function, u'hi'),\n   (Token.Text, u'\\n'),\n   (Token.Generic.Output, u'hi\\n')]")


----------------------------------------------------------------------
Ran 2061 tests in 48.091s

FAILED (SKIP=9, failures=1)
Makefile:53: recipe for target 'test' failed
make: *** [test] Error 1

Please, help!