https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94004
--- Comment #2 from Martin Sebor <msebor at gcc dot gnu.org> ---
Bisection points to r254630 which doesn't look related to -Walloca:
commit 025d57f037ad13eb479818b677ef4be4d97b639c
Author: Martin Sebor <mse...@redhat.com>
Date: Fri Nov 10 16:35:26 2017 +0000
PR c/81117 - Improve buffer overflow checking in strncpy
gcc/ChangeLog:
PR c/81117
* builtins.c (compute_objsize): Handle arrays that
compute_builtin_object_size likes to fail for. Make extern.
* builtins.h (compute_objsize): Declare.
(check_strncpy_sizes): New function.
(expand_builtin_strncpy): Call check_strncpy_sizes.
* gimple-fold.c (gimple_fold_builtin_strncpy): Implement
-Wstringop-truncation.
(gimple_fold_builtin_strncat): Same.
* gimple.c (gimple_build_call_from_tree): Set call location.
* tree-ssa-strlen.c (strlen_to_stridx): New global variable.
(maybe_diag_bound_equal_length, is_strlen_related_p): New
functions.
(handle_builtin_stxncpy, handle_builtin_strncat): Same.
(handle_builtin_strlen): Use strlen_to_stridx.
(strlen_optimize_stmt): Handle flavors of strncat, strncpy, and
stpncpy.
Use strlen_to_stridx.
(pass_strlen::execute): Release strlen_to_stridx.
* doc/invoke.texi (-Wsizeof-pointer-memaccess): Document
enhancement.
(-Wstringop-truncation): Document new option.
gcc/ada/ChangeLog:
PR c/81117
* ada/adadecode.c (__gnat_decode): Use memcpy instead of strncpy.
* ada/argv.c (__gnat_fill_arg, __gnat_fill_env): Same.
gcc/c-family/ChangeLog:
PR c/81117
* c-common.c (catenate_strings): Use memcpy instead of strncpy.
* c-warn.c (sizeof_pointer_memaccess_warning): Handle arrays.
* c.opt (-Wstringop-truncation): New option.
...
From-SVN: r254630
