Bug path

‘test’: events 1-2

18	void test (struct foo f)
	^~~~
	\|
	(1) entry to ‘test’
[...]
22	calls_free (f.m_p);
	~~~~~~~~~~~~~~~~~~
	\|
	(2) calling ‘calls_free’ from ‘test’

‘calls_free’: events 3-4

6	calls_free (void *victim)
	^~~~~~~~~~
	\|
	(3) entry to ‘calls_free’
7	{
8	free (victim); /* { dg-warning "double-'free' of 'victim'" } */
	~~~~~~~~~~~~~
	\|
	(4) first ‘free’ here

‘test’: events 5-6

22	calls_free (f.m_p);
	^~~~~~~~~~~~~~~~~~
	\|
	(5) returning to ‘test’ from ‘calls_free’
[...]
26	calls_free (f.m_p); /* { dg-message "passing freed pointer '<unknown>' in call to 'calls_free' from 'test'" } */
	~~~~~~~~~~~~~~~~~~
	\|
	(6) passing freed pointer ‘<unknown>’ in call to ‘calls_free’ from ‘test’

‘calls_free’: events 7-8

6	calls_free (void *victim)
	^~~~~~~~~~
	\|
	(7) entry to ‘calls_free’
7	{
8	free (victim); /* { dg-warning "double-'free' of 'victim'" } */
	~~~~~~~~~~~~~
	\|
	(8) second ‘free’ here; first ‘free’ was at (4)