From a76c1d62979c58606a134dcfbf9be977d68331f6 Mon Sep 17 00:00:00 2001 From: Martin Sebor Date: Mon, 27 Jul 2020 13:54:50 -0600 Subject: Diagnose just-past-the-end references for minor array bounds. Resolves: PR tree-optimization/84079 - missing -Warray-bounds taking the address of past-the-end element of a multidimensional array gcc/ChangeLog: PR tree-optimization/84079 * gimple-array-bounds.cc (array_bounds_checker::check_addr_expr): Only allow just-past-the-end references for the most significant array bound. gcc/testsuite/ChangeLog: PR tree-optimization/84079 * gcc.dg/Warray-bounds-62.c: New test. --- gcc/gimple-array-bounds.cc | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) (limited to 'gcc/gimple-array-bounds.cc') diff --git a/gcc/gimple-array-bounds.cc b/gcc/gimple-array-bounds.cc index 352d074..c2dd666 100644 --- a/gcc/gimple-array-bounds.cc +++ b/gcc/gimple-array-bounds.cc @@ -519,14 +519,21 @@ array_bounds_checker::check_mem_ref (location_t location, tree ref, void array_bounds_checker::check_addr_expr (location_t location, tree t) { + /* For the most significant subscript only, accept taking the address + of the just-past-the-end element. */ + bool ignore_off_by_one = true; + /* Check each ARRAY_REF and MEM_REF in the reference chain. */ do { bool warned = false; if (TREE_CODE (t) == ARRAY_REF) - warned = check_array_ref (location, t, true /*ignore_off_by_one*/); + { + warned = check_array_ref (location, t, ignore_off_by_one); + ignore_off_by_one = false; + } else if (TREE_CODE (t) == MEM_REF) - warned = check_mem_ref (location, t, true /*ignore_off_by_one*/); + warned = check_mem_ref (location, t, ignore_off_by_one); if (warned) TREE_NO_WARNING (t) = true; -- cgit v1.1