gimple-ssa-warn-access: Adjust maybe_warn_nonstring_arg for nonstring multidimensional arrays [PR117178]

The following patch fixes 4 xfails in attr-nonstring-11.c (and results in 2
false positive warnings in attr-nonstring-12.c not being produced either).
The thing is that maybe_warn_nonstring_arg simply assumed that nonstring
arrays must be single-dimensional, so when it sees a nonstring decl with
ARRAY_TYPE, it just used its dimension.  With multi-dimensional arrays
that is not the right dimension to use though, it can be dimension of
some outer dimension, e.g. if we have
char a[5][6][7] __attribute__((nonstring)) if decl is
a[5] it would assume maximum non-NUL terminated string length of 5 rather than
7, if a[5][6] it would assume 6 and only for a[5][6][0] it would assume the
correct 7.  So, the following patch looks through all the outer dimensions
to reach the innermost one (which for attribute nonstring is guaranteed to
have char/unsigned char/signed char element type).

2025-03-10  Jakub Jelinek  <jakub@redhat.com>

	PR c/117178
	* gimple-ssa-warn-access.cc (maybe_warn_nonstring_arg): Look through
	multi-dimensional array types, stop at the innermost ARRAY_TYPE.

	* c-c++-common/attr-nonstring-11.c: Remove xfails.
	* c-c++-common/attr-nonstring-12.c (warn_strcmp_cst_1,
	warn_strcmp_cst_2): Don't expect any warnings here.
	(warn_strcmp_cst_3, warn_strcmp_cst_4): New functions with expected
	warnings.

0 files changed, 0 insertions, 0 deletions