PR middle-end/91679 - missing -Warray-bounds accessing a member array in a local buffer

PR middle-end/91679 - missing -Warray-bounds accessing a member array in a local buffer
PR middle-end/91647 - new FAILs for Warray-bounds-8 and Wstringop-overflow-3.C
PR middle-end/91463 - missing -Warray-bounds accessing past the end of a statically initialized flexible array member
PR middle-end/92312 - bogus -Wstringop-overflow storing into a trailing array backed by larger buffer

gcc/ChangeLog:

	PR middle-end/91679
	PR middle-end/91647
	PR middle-end/91463
	PR middle-end/92312
	* c-family/c-pretty-print.c (direct_abstract_declarator): Print
	bound in zero-length arrays.
	* gcc/c-family/c.opt (-Wzero-length-bounds): New option.
	* gcc/doc/invoke.texi (-Wzero-length-bounds): Document.
	* gimple-match-head.c (try_conditional_simplification): Use memcpy
	instead of a hand-rolled loop to avoid PR 92323.
	* tree-vrp.c (vrp_prop::check_array_ref): Handle trailing arrays
	with initializers.
	(vrp_prop::check_mem_ref): Handle declared struct objects.
	* tree.c (last_field): New function.
	(array_at_struct_end_p): Handle MEM_REF.
	(get_initializer_for): New helper.
	(component_ref_size): Add argument.  Rename locals.  Call
	get_initializer_for instead of fold_ctor_reference.  Correct handling
	of flexible array members.
	* wide-int.h (generic_wide_int <storage>::sign_mask): Assert invariant.

gcc/testsuite/ChangeLog:

	PR middle-end/91679
	PR middle-end/91647
	PR middle-end/91463
	PR middle-end/92312
	* c-c++-common/Warray-bounds-2.c: Disable VRP.  Adjust expected messages.
	* g++.dg/warn/Warray-bounds-8.C: Remove xfails.
	* gcc.dg/Warray-bounds-48.c: New test.
	* gcc.dg/Warray-bounds-49.c: New test.
	* gcc.dg/Wstringop-overflow-16.c: Adjust text of expected messages.
	* gcc.dg/Wstringop-overflow-21.c: New test.
	* gcc.dg/Wzero-length-array-bounds.c: New test.
	* gcc.dg/pr36902.c: Remove xfail.
	* gcc.dg/strlenopt-57.c: Add an expected warning.

From-SVN: r277728

1 files changed, 59 insertions, 0 deletions

diff --git a/gcc/testsuite/gcc.dg/Wstringop-overflow-21.c b/gcc/testsuite/gcc.dg/Wstringop-overflow-21.c
new file mode 100644
index 0000000..3a27460
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/Wstringop-overflow-21.c
@@ -0,0 +1,59 @@
+/* PR middle-end/92312 - bogus -Wstringop-overflow storing into a trailing
+   array backed by larger buffer
+   { dg-do compile }
+   { dg-options "-O2 -Wall -Wno-array-bounds" } */
+
+struct S0 { char a, b[0]; };
+
+void sink (void*);
+
+void test_memset_zero_length (void)
+{
+  char a[3];
+  struct S0 *p = (struct S0*)a;
+  p->a = 0;
+  __builtin_memset (p->b, 0, 2);
+  sink (p);
+
+  __builtin_memset (p->b, 0, 3);    // { dg-warning "\\\[-Wstringop-overflow" }
+  sink (p);
+}
+
+void test_store_zero_length (int i)
+{
+  char a[3];
+  struct S0 *p = (struct S0*)a;
+  p->a = 0;
+  p->b[0] = 0;
+  p->b[1] = 1;                      // { dg-bogus "\\\[-Wstringop-overflow" }
+  p->b[2] = 2;                      // { dg-warning "\\\[-Wstringop-overflow" }
+  p->b[i] = 2;
+  sink (p);
+}
+
+
+struct Sx { char a, b[]; };
+
+void test_memset_flexarray (int i)
+{
+  char a[3];
+  struct Sx *p = (struct Sx*)a;
+  p->a = 0;
+  __builtin_memset (p->b, 0, 2);
+  sink (p);
+
+  __builtin_memset (p->b, 0, 3);    // { dg-warning "\\\[-Wstringop-overflow" }
+  sink (p);
+}
+
+void test_store_flexarray (int i)
+{
+  char a[3];
+  struct Sx *p = (struct Sx*)a;
+  p->a = 0;
+  p->b[0] = 0;
+  p->b[1] = 1;                      // { dg-bogus "\\\[-Wstringop-overflow" }
+  p->b[2] = 1;                      // { dg-warning "\\\[-Wstringop-overflow" }
+  p->b[i] = 2;
+  sink (p);
+}