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analyzer: fix ICE on escaped unknown pointers [PR96611]

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PR analyzer/96611 reports an ICE within the handling for unknown
functions, when passing a pointer to something accessed via a
global pointer, after an unknown function has already been called.

The first unknown function leads to the store being flagged, so
the access to the global pointer leads to (*unknown_svalue) for
the base region of the argument to the 2nd function, and thus
*unknown_svalue being reachable by the 2nd unknown function,
triggering an assertion failure.

Handle this case by rejecting attempts to get a cluster for
the unknown pointer, fixing the ICE.

gcc/analyzer/ChangeLog:
	PR analyzer/96611
	* store.cc (store::mark_as_escaped): Reject attempts to
	get a cluster for an unknown pointer.

gcc/testsuite/ChangeLog:
	PR analyzer/96611
	* gcc.dg/analyzer/pr96611.c: New test.
This commit is contained in:
David Malcolm 2020-08-14 10:48:30 -04:00
parent 7e62503862
commit ee88b53606
2 changed files with 17 additions and 0 deletions
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3
gcc/analyzer/store.cc
View file

@ -1691,6 +1691,9 @@ store::mark_as_escaped (const region *base_reg)
gcc_assert (base_reg);
gcc_assert (base_reg->get_base_region () == base_reg);
if (base_reg->symbolic_for_unknown_ptr_p ())
return;
binding_cluster *cluster = get_or_create_cluster (base_reg);
cluster->mark_as_escaped ();
}

14
gcc/testsuite/gcc.dg/analyzer/pr96611.c Normal file
View file

@ -0,0 +1,14 @@
struct s { int a; } *ptr;
void unknown_int_ptr (int *);
void unknown_void (void);
void test_1 ()
{
unknown_int_ptr (&ptr->a);
}
void test_2 ()
{
unknown_void ();
unknown_int_ptr (&ptr->a);
}