Whilst analyzing the reproducer for detecting CVE-2005-1689
(krb5-1.4.1's src/lib/krb5/krb/recvauth.c), the analyzer reported
11 double-free diagnostics on lines of the form:
krb5_xfree(inbuf.data);
with no deduplication occcurring.
The root cause is that the diagnostics each have a COMPONENT_REF for
the inbuf.data, but they are different trees, and the de-duplication
logic was using pointer equality.
This patch replaces the pointer equality tests with calls to a new
pending_diagnostic::same_tree_p, implemented using simple_cst_equal.
With this patch, de-duplication occurs, and only 3 diagnostics are
reported. The 11 diagnostics are partitioned into 3 dedupe keys,
2 with 2 duplicates and 1 with 7 duplicates.
gcc/analyzer/ChangeLog:
* diagnostic-manager.cc (saved_diagnostic::operator==): Move here
from header. Replace pointer equality test on m_var with call to
pending_diagnostic::same_tree_p.
* diagnostic-manager.h (saved_diagnostic::operator==): Move to
diagnostic-manager.cc.
* pending-diagnostic.cc (pending_diagnostic::same_tree_p): New.
* pending-diagnostic.h (pending_diagnostic::same_tree_p): New.
* sm-file.cc (file_diagnostic::subclass_equal_p): Replace pointer
equality on m_arg with call to pending_diagnostic::same_tree_p.
* sm-malloc.cc (malloc_diagnostic::subclass_equal_p): Likewise.
(possible_null_arg::subclass_equal_p): Likewise.
(null_arg::subclass_equal_p): Likewise.
(free_of_non_heap::subclass_equal_p): Likewise.
* sm-pattern-test.cc (pattern_match::operator==): Likewise.
* sm-sensitive.cc (exposure_through_output_file::operator==):
Likewise.
* sm-taint.cc (tainted_array_index::operator==): Likewise.
gcc/testsuite/ChangeLog:
* gcc.dg/analyzer/CVE-2005-1689-dedupe-issue.c: New test.
