On Sat, 24 Apr 2021, David Malcolm wrote:
> PR analyzer/100244 reports an ICE on a -Wanalyzer-free-of-non-heap
> due to a case where free_of_non_heap::describe_state_change can be
> passed a NULL change.m_expr for a suitably complicated symbolic value.
>
> Bulletproof it by checking for change.m_expr being NULL before
> dereferencing it.
>
> Successfully bootstrapped & regrtested on x86_64-pc-linux-gnu.
> Pushed to trunk for gcc 12 as
> r12-108-g61bfff562e3b6091d5a0a412a7d496bd523868a8.
>
> This ICE is technically a regression for gcc 11.
> The fix is trivial and confined to the analyzer.
>
> OK to push to gcc 11 branch?
OK after the 11.1 release.
Richard.
> gcc/analyzer/ChangeLog:
> PR analyzer/100244
> * sm-malloc.cc (free_of_non_heap::describe_state_change):
> Bulletproof against change.m_expr being NULL.
>
> gcc/testsuite/ChangeLog:
> PR analyzer/100244
> * g++.dg/analyzer/pr100244.C: New test.
> ---
> gcc/analyzer/sm-malloc.cc | 2 +-
> gcc/testsuite/g++.dg/analyzer/pr100244.C | 22 ++++++++++++++++++++++
> 2 files changed, 23 insertions(+), 1 deletion(-)
> create mode 100644 gcc/testsuite/g++.dg/analyzer/pr100244.C
>
> diff --git a/gcc/analyzer/sm-malloc.cc b/gcc/analyzer/sm-malloc.cc
> index 1d5b8601b1f..f02b73ab90a 100644
> --- a/gcc/analyzer/sm-malloc.cc
> +++ b/gcc/analyzer/sm-malloc.cc
> @@ -1303,7 +1303,7 @@ public:
> {
> /* Attempt to reconstruct what kind of pointer it is.
> (It seems neater for this to be a part of the state, though). */
> - if (TREE_CODE (change.m_expr) == SSA_NAME)
> + if (change.m_expr && TREE_CODE (change.m_expr) == SSA_NAME)
> {
> gimple *def_stmt = SSA_NAME_DEF_STMT (change.m_expr);
> if (gcall *call = dyn_cast <gcall *> (def_stmt))
> diff --git a/gcc/testsuite/g++.dg/analyzer/pr100244.C
> b/gcc/testsuite/g++.dg/analyzer/pr100244.C
> new file mode 100644
> index 00000000000..261b3cfff57
> --- /dev/null
> +++ b/gcc/testsuite/g++.dg/analyzer/pr100244.C
> @@ -0,0 +1,22 @@
> +// { dg-additional-options "-O1 -Wno-free-nonheap-object" }
> +
> +inline void *operator new (__SIZE_TYPE__, void *__p) { return __p; }
> +
> +struct __aligned_buffer {
> + int _M_storage;
> + int *_M_addr() { return &_M_storage; }
> +};
> +
> +struct _Hashtable_alloc {
> + int _M_single_bucket;
> + int *_M_buckets;
> + _Hashtable_alloc () { _M_buckets = &_M_single_bucket; }
> + ~_Hashtable_alloc () { delete _M_buckets; } // { dg-warning "not on the
> heap" }
> +};
> +
> +void
> +test01 (__aligned_buffer buf)
> +{
> + _Hashtable_alloc *tmp = new (buf._M_addr ()) _Hashtable_alloc;
> + tmp->~_Hashtable_alloc ();
> +}
>
--
Richard Biener <rguent...@suse.de>
SUSE Software Solutions Germany GmbH, Maxfeldstrasse 5, 90409 Nuernberg,
Germany; GF: Felix Imendörffer; HRB 36809 (AG Nuernberg)
