From d8aad7864e5b4c654dcea86b98085baf36d8db76 Mon Sep 17 00:00:00 2001
From: msebor <msebor@138bc75d-0d04-0410-961f-82ee72b054a4>
Date: Fri, 10 Nov 2017 16:35:26 +0000
Subject: 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.

gcc/fortran/ChangeLog:

	PR c/81117
	* gcc/fortran/decl.c (build_sym): Use strcpy instead of strncpy.

gcc/objc/ChangeLog:

	PR c/81117
	* objc-encoding.c (encode_type): Use memcpy instead of strncpy.

gcc/testsuite/ChangeLog:

	PR c/81117
	* c-c++-common/Wsizeof-pointer-memaccess3.c: New test.
	* c-c++-common/Wstringop-overflow.c: Same.
	* c-c++-common/Wstringop-truncation.c: Same.
	* c-c++-common/Wsizeof-pointer-memaccess2.c: Adjust.
	* c-c++-common/attr-nonstring-2.c: New test.
	* g++.dg/torture/Wsizeof-pointer-memaccess1.C: Adjust.
	* g++.dg/torture/Wsizeof-pointer-memaccess2.C: Same.
	* gcc.dg/torture/pr63554.c: Same.
	* gcc.dg/Walloca-1.c: Disable macro tracking.



git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@254630 138bc75d-0d04-0410-961f-82ee72b054a4
---
 gcc/testsuite/c-c++-common/attr-nonstring-1.c | 60 +++++++++++++++++++++++++++
 1 file changed, 60 insertions(+)
 create mode 100644 gcc/testsuite/c-c++-common/attr-nonstring-1.c

(limited to 'gcc/testsuite/c-c++-common/attr-nonstring-1.c')

diff --git a/gcc/testsuite/c-c++-common/attr-nonstring-1.c b/gcc/testsuite/c-c++-common/attr-nonstring-1.c
new file mode 100644
index 00000000000..10a66887fa2
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/attr-nonstring-1.c
@@ -0,0 +1,60 @@
+/* Test to exercise attribute "nonstring" syntax.
+   { dg-do compile }
+   { dg-options "-Wattributes" }  */
+
+#define ATTR(list) __attribute__ (list)
+#define NONSTR     ATTR ((nonstring))
+
+/* Verify it's accepted on char arrays.  */
+extern NONSTR char nsx_1[];
+extern char NONSTR nsx_2[];
+extern char nsx_3[] NONSTR;
+
+extern NONSTR char ns1[1];
+extern char NONSTR ns3[3];
+extern char ns5[5] NONSTR;
+
+/* Verify it's accepted on char pointers.  */
+extern NONSTR char* pns_1;
+extern char NONSTR* pns_2;
+extern char* NONSTR pns_3;
+
+struct S
+{
+/* Verify it's accepted on char member pointers.  */
+  NONSTR char* mpns_1;
+  char NONSTR* mpns_2;
+  char* NONSTR mpns_3;
+
+/* Verify it's accepted on char member arrays.  */
+  NONSTR char mns1[1];
+  char NONSTR mns3[3];
+  char mns5[5] NONSTR;
+
+/* Verify it's accepted on char flexible array members.  */
+  char mnsx[] NONSTR;
+};
+
+/* Verify it's rejected on non-array and non-pointer objects.  */
+extern NONSTR char c1;         /* { dg-warning ".nonstring. attribute ignored on objects of type .char." } */
+
+extern NONSTR int i1;         /* { dg-warning ".nonstring. attribute ignored on objects of type .int." } */
+
+extern NONSTR int ia1[];      /* { dg-warning ".nonstring. attribute ignored on objects of type .int *\\\[\\\]." } */
+
+extern NONSTR int* pi1;       /* { dg-warning ".nonstring. attribute ignored on objects of type .int *\\*." } */
+
+extern NONSTR
+void f (void);                /* { dg-warning ".nonstring. attribute does not apply to functions" } */
+
+struct NONSTR
+NonStrType { int i; };        /* { dg-warning ".nonstring. attribute does not apply to types" } */
+
+typedef char NONSTR nschar_t; /* { dg-warning ".nonstring. attribute does not apply to types" } */
+
+void func (NONSTR char *pns1, char NONSTR *pns2, char* NONSTR pns3)
+{
+  (void)pns1;
+  (void)pns2;
+  (void)pns3;
+}
-- 
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