When address of packed member of struct or union is taken, it may result
in an unaligned pointer value. This patch adds -Waddress-of-packed-member
to warn it:
$ cat x.i
struct pair_t
{
char c;
int i;
} __attribute__ ((packed));
extern struct pair_t p;
int *addr = &p.i;
$ gcc -O2 -S x.i
x.i:8:13: warning: initialization of 'int *' from address of packed member of
'struct pair_t' may result in an unaligned pointer value
[-Waddress-of-packed-member]
int *addr = &p.i;
^
$
This warning is enabled by default.
Tested on i686 and x86-64. OK for trunk?
H.J.
---
gcc/c/
PR c/51628
* doc/invoke.texi: Document -Wno-address-of-packed-member.
gcc/c-family/
PR c/51628
* c-common.h (warn_for_address_of_packed_member): New.
* c-warn.c (warn_for_address_of_packed_member): New function.
* c.opt: Add -Wno-address-of-packed-member.
gcc/c/
PR c/51628
* c-typeck.c (convert_for_assignment): Call
warn_for_address_of_packed_member. Issue an warning if address
of packed member is taken.
gcc/cp/
PR c/51628
* call.c (convert_for_arg_passing): Call
warn_for_address_of_packed_member. Issue an warning if address
of packed member is taken.
* typeck.c (convert_for_assignment): Likewise.
gcc/testsuite/
PR c/51628
* c-c++-common/pr51628-1.c: New tests.
* c-c++-common/pr51628-2.c: Likewise.
* c-c++-common/pr51628-3.c: Likewise.
* c-c++-common/pr51628-4.c: Likewise.
* c-c++-common/pr51628-5.c: Likewise.
* c-c++-common/pr51628-6.c: Likewise.
* c-c++-common/ubsan/align-2.c: Add -Wno-address-of-packed-member.
* c-c++-common/ubsan/align-4.c: Likewise.
* c-c++-common/ubsan/align-6.c: Likewise.
* c-c++-common/ubsan/align-7.c: Likewise.
* c-c++-common/ubsan/align-8.c: Likewise.
* g++.dg/ubsan/align-2.C: Likewise.
---
gcc/c-family/c-common.h | 1 +
gcc/c-family/c-warn.c | 38 +++++++++++++++++++++++++++
gcc/c-family/c.opt | 4 +++
gcc/c/c-typeck.c | 40 ++++++++++++++++++++++++++++-
gcc/cp/call.c | 8 ++++++
gcc/cp/typeck.c | 41 ++++++++++++++++++++++++++++++
gcc/doc/invoke.texi | 11 ++++++--
gcc/testsuite/c-c++-common/pr51628-1.c | 29 +++++++++++++++++++++
gcc/testsuite/c-c++-common/pr51628-2.c | 29 +++++++++++++++++++++
gcc/testsuite/c-c++-common/pr51628-3.c | 35 +++++++++++++++++++++++++
gcc/testsuite/c-c++-common/pr51628-4.c | 35 +++++++++++++++++++++++++
gcc/testsuite/c-c++-common/pr51628-5.c | 35 +++++++++++++++++++++++++
gcc/testsuite/c-c++-common/pr51628-6.c | 35 +++++++++++++++++++++++++
gcc/testsuite/c-c++-common/ubsan/align-2.c | 2 +-
gcc/testsuite/c-c++-common/ubsan/align-4.c | 2 +-
gcc/testsuite/c-c++-common/ubsan/align-6.c | 2 +-
gcc/testsuite/c-c++-common/ubsan/align-7.c | 2 +-
gcc/testsuite/c-c++-common/ubsan/align-8.c | 2 +-
gcc/testsuite/g++.dg/ubsan/align-2.C | 2 +-
19 files changed, 344 insertions(+), 9 deletions(-)
create mode 100644 gcc/testsuite/c-c++-common/pr51628-1.c
create mode 100644 gcc/testsuite/c-c++-common/pr51628-2.c
create mode 100644 gcc/testsuite/c-c++-common/pr51628-3.c
create mode 100644 gcc/testsuite/c-c++-common/pr51628-4.c
create mode 100644 gcc/testsuite/c-c++-common/pr51628-5.c
create mode 100644 gcc/testsuite/c-c++-common/pr51628-6.c
diff --git a/gcc/c-family/c-common.h b/gcc/c-family/c-common.h
index d090881e95d..ef31e4d0aa2 100644
--- a/gcc/c-family/c-common.h
+++ b/gcc/c-family/c-common.h
@@ -1384,6 +1384,7 @@ extern void c_do_switch_warnings (splay_tree, location_t,
tree, tree, bool,
bool);
extern void warn_for_omitted_condop (location_t, tree);
extern void warn_for_restrict (unsigned, tree *, unsigned);
+extern tree warn_for_address_of_packed_member (tree type, tree rhs);
/* Places where an lvalue, or modifiable lvalue, may be required.
Used to select diagnostic messages in lvalue_error and
diff --git a/gcc/c-family/c-warn.c b/gcc/c-family/c-warn.c
index 7d87c455ec0..ac0a2ffcb42 100644
--- a/gcc/c-family/c-warn.c
+++ b/gcc/c-family/c-warn.c
@@ -2576,3 +2576,41 @@ warn_for_multistatement_macros (location_t body_loc,
location_t next_loc,
inform (guard_loc, "some parts of macro expansion are not guarded by "
"this %qs clause", guard_tinfo_to_string (keyword));
}
+
+/* Return struct or union type if the right hand type, RHS, is the
+ address of packed member of struct or union when assigning to TYPE.
+ Otherwise, return NULL_TREE. */
+
+tree
+warn_for_address_of_packed_member (tree type, tree rhs)
+{
+ if (!warn_address_of_packed_member)
+ return NULL_TREE;
+
+ if (TREE_CODE (rhs) == ADDR_EXPR && POINTER_TYPE_P (type))
+ {
+ tree base = TREE_OPERAND (rhs, 0);
+ if (TREE_CODE (base) == COMPONENT_REF)
+ {
+ tree field = TREE_OPERAND (base, 1);
+ if (TREE_CODE (field) == FIELD_DECL && DECL_PACKED (field))
+ {
+ tree field_type = TREE_TYPE (field);
+ unsigned int type_align = TYPE_ALIGN (field_type);
+ tree context = DECL_CONTEXT (field);
+ unsigned int record_align = TYPE_ALIGN (context);
+ if ((record_align % type_align) != 0)
+ return context;
+ type_align /= BITS_PER_UNIT;
+ unsigned HOST_WIDE_INT field_off
+ = (tree_to_uhwi (DECL_FIELD_OFFSET (field))
+ + (tree_to_uhwi (DECL_FIELD_BIT_OFFSET (field))
+ / BITS_PER_UNIT));
+ if ((field_off % type_align) != 0)
+ return context;
+ }
+ }
+ }
+
+ return NULL_TREE;
+}
diff --git a/gcc/c-family/c.opt b/gcc/c-family/c.opt
index 16a515afd55..686d52a2055 100644
--- a/gcc/c-family/c.opt
+++ b/gcc/c-family/c.opt
@@ -599,6 +599,10 @@ Wincompatible-pointer-types
C ObjC Var(warn_incompatible_pointer_types) Init(1) Warning
Warn when there is a conversion between pointers that have incompatible types.
+Waddress-of-packed-member
+C ObjC C++ ObjC++ Var(warn_address_of_packed_member) Init(1) Warning
+Warn when the address of packed member of struct or union is taken.
+
Winit-self
C ObjC C++ ObjC++ Var(warn_init_self) Warning LangEnabledBy(C++ ObjC++,Wall)
Warn about variables which are initialized to themselves.
diff --git a/gcc/c/c-typeck.c b/gcc/c/c-typeck.c
index e22bc740bca..8e31d6cc5fd 100644
--- a/gcc/c/c-typeck.c
+++ b/gcc/c/c-typeck.c
@@ -6495,7 +6495,45 @@ convert_for_assignment (location_t location, location_t
expr_loc, tree type,
}
if (TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (rhstype))
- return rhs;
+ {
+ tree context = warn_for_address_of_packed_member (type, orig_rhs);
+ if (context)
+ switch (errtype)
+ {
+ case ic_argpass:
+ warning_at (expr_loc, OPT_Waddress_of_packed_member,
+ "passing argument %d %qT of %qE from address "
+ "of packed member of %qT may result in an "
+ "unaligned pointer value",
+ parmnum, type, rname, context);
+ break;
+ case ic_assign:
+ warning_at (location, OPT_Waddress_of_packed_member,
+ "assignment to %qT from address of packed "
+ "member of %qT may result in an unaligned "
+ "pointer value",
+ type, context);
+ break;
+ case ic_init:
+ warning_at (location, OPT_Waddress_of_packed_member,
+ "initialization of %qT from address of packed "
+ "member of %qT may result in an unaligned "
+ "pointer value",
+ type, context);
+ break;
+ case ic_return:
+ warning_at (location, OPT_Waddress_of_packed_member,
+ "returning address of packed member of %qT "
+ "from a function with return type %qT may "
+ "result in an unaligned pointer value",
+ context, type);
+ break;
+ default:
+ gcc_unreachable ();
+ }
+
+ return rhs;
+ }
if (coder == VOID_TYPE)
{
diff --git a/gcc/cp/call.c b/gcc/cp/call.c
index f5542850cea..8672ab0d58c 100644
--- a/gcc/cp/call.c
+++ b/gcc/cp/call.c
@@ -7416,6 +7416,14 @@ convert_for_arg_passing (tree type, tree val,
tsubst_flags_t complain)
}
maybe_warn_parm_abi (type, EXPR_LOC_OR_LOC (val, input_location));
}
+
+ tree context = warn_for_address_of_packed_member (type, val);
+ if (context)
+ warning (OPT_Waddress_of_packed_member,
+ "passing argument of type %qT from address of member of "
+ "packed %qT may result in an unaligned pointer value",
+ type, context);
+
return val;
}
diff --git a/gcc/cp/typeck.c b/gcc/cp/typeck.c
index f0dc03de111..1199c27d2f0 100644
--- a/gcc/cp/typeck.c
+++ b/gcc/cp/typeck.c
@@ -8887,6 +8887,47 @@ convert_for_assignment (tree type, tree rhs,
TREE_NO_WARNING (rhs) = 1;
}
+ tree context = warn_for_address_of_packed_member (type, rhs);
+ if (context)
+ switch (errtype)
+ {
+ case ICR_ARGPASS:
+ case ICR_DEFAULT_ARGUMENT:
+ warning (OPT_Waddress_of_packed_member,
+ "passing argument %d %qT of %qD from address of "
+ "packed member of %qT may result in an unaligned "
+ "pointer value",
+ parmnum, type, fndecl, context);
+ break;
+ case ICR_CONVERTING:
+ warning (OPT_Waddress_of_packed_member,
+ "converting to %qT from address of packed member of "
+ "%qT may result in an unaligned pointer value",
+ type, context);
+ break;
+ case ICR_ASSIGN:
+ warning (OPT_Waddress_of_packed_member,
+ "assignment to %qT from address of packed member of "
+ "%qT may result in an unaligned pointer value",
+ type, context);
+ break;
+ case ICR_INIT:
+ warning (OPT_Waddress_of_packed_member,
+ "initialization of %qT from address of packed member "
+ "of %qT may result in an unaligned pointer value",
+ type, context);
+ break;
+ case ICR_RETURN:
+ warning (OPT_Waddress_of_packed_member,
+ "returning address of packed member of %qT from a "
+ "function with return type %qT may result in an "
+ "unaligned pointer value",
+ context, type);
+ break;
+ default:
+ gcc_unreachable ();
+ }
+
return perform_implicit_conversion_flags (strip_top_quals (type), rhs,
complain, flags);
}
diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
index 28c61a078d2..13fd0abca3a 100644
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -259,8 +259,8 @@ Objective-C and Objective-C++ Dialects}.
@xref{Warning Options,,Options to Request or Suppress Warnings}.
@gccoptlist{-fsyntax-only -fmax-errors=@var{n} -Wpedantic @gol
-pedantic-errors @gol
--w -Wextra -Wall -Waddress -Waggregate-return @gol
--Walloc-zero -Walloc-size-larger-than=@var{n}
+-w -Wextra -Wall -Waddress -Waddress-of-packed-member @gol
+-Waggregate-return -Walloc-zero -Walloc-size-larger-than=@var{n} @gol
-Walloca -Walloca-larger-than=@var{n} @gol
-Wno-aggressive-loop-optimizations -Warray-bounds -Warray-bounds=@var{n} @gol
-Wno-attributes -Wbool-compare -Wbool-operation @gol
@@ -6374,6 +6374,13 @@ behavior and are not portable in C, so they usually
indicate that the
programmer intended to use @code{strcmp}. This warning is enabled by
@option{-Wall}.
+@item -Waddress-of-packed-member
+@opindex Waddress-of-packed-member
+@opindex Wno-address-of-packed-member
+Warn when the address of packed member of struct or union is taken,
+which usually results in an unaligned pointer value. This is
+enabled by default.
+
@item -Wlogical-op
@opindex Wlogical-op
@opindex Wno-logical-op
diff --git a/gcc/testsuite/c-c++-common/pr51628-1.c
b/gcc/testsuite/c-c++-common/pr51628-1.c
new file mode 100644
index 00000000000..5324f9cc964
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/pr51628-1.c
@@ -0,0 +1,29 @@
+/* PR c/51628. */
+/* { dg-do compile } */
+/* { dg-options "-O" } */
+
+struct pair_t
+{
+ int x;
+ int i;
+} __attribute__((packed, aligned (4)));
+
+extern struct pair_t p;
+extern int *x;
+extern void bar (int *);
+
+int *addr = &p.i;
+
+int *
+foo (void)
+{
+ struct pair_t arr[2] = { { 1, 10 }, { 2, 20 } };
+ int *p0, *p1;
+ p0 = &arr[0].i;
+ bar (p0);
+ p1 = &arr[1].i;
+ bar (p1);
+ bar (&p.i);
+ x = &p.i;
+ return &p.i;
+}
diff --git a/gcc/testsuite/c-c++-common/pr51628-2.c
b/gcc/testsuite/c-c++-common/pr51628-2.c
new file mode 100644
index 00000000000..abfb84ddd05
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/pr51628-2.c
@@ -0,0 +1,29 @@
+/* PR c/51628. */
+/* { dg-do compile } */
+/* { dg-options "-O" } */
+
+struct pair_t
+{
+ int x;
+ int i;
+} __attribute__((packed, aligned (8)));
+
+extern struct pair_t p;
+extern int *x;
+extern void bar (int *);
+
+int *addr = &p.i;
+
+int *
+foo (void)
+{
+ struct pair_t arr[2] = { { 1, 10 }, { 2, 20 } };
+ int *p0, *p1;
+ p0 = &arr[0].i;
+ bar (p0);
+ p1 = &arr[1].i;
+ bar (p1);
+ bar (&p.i);
+ x = &p.i;
+ return &p.i;
+}
diff --git a/gcc/testsuite/c-c++-common/pr51628-3.c
b/gcc/testsuite/c-c++-common/pr51628-3.c
new file mode 100644
index 00000000000..0ea94c845a0
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/pr51628-3.c
@@ -0,0 +1,35 @@
+/* PR c/51628. */
+/* { dg-do compile } */
+/* { dg-options "-O" } */
+
+struct pair_t
+{
+ int x;
+ int i;
+} __attribute__((packed, aligned (2)));
+
+extern struct pair_t p;
+extern int *x;
+extern void bar (int *);
+
+int *addr = &p.i;
+/* { dg-warning "may result in an unaligned pointer value" "" { target *-*-* }
.-1 } */
+
+int *
+foo (void)
+{
+ struct pair_t arr[2] = { { 1, 10 }, { 2, 20 } };
+ int *p0, *p1;
+ p0 = &arr[0].i;
+/* { dg-warning "may result in an unaligned pointer value" "" { target *-*-* }
.-1 } */
+ bar (p0);
+ p1 = &arr[1].i;
+/* { dg-warning "may result in an unaligned pointer value" "" { target *-*-* }
.-1 } */
+ bar (p1);
+ bar (&p.i);
+/* { dg-warning "may result in an unaligned pointer value" "" { target *-*-* }
.-1 } */
+ x = &p.i;
+/* { dg-warning "may result in an unaligned pointer value" "" { target *-*-* }
.-1 } */
+ return &p.i;
+/* { dg-warning "may result in an unaligned pointer value" "" { target *-*-* }
.-1 } */
+}
diff --git a/gcc/testsuite/c-c++-common/pr51628-4.c
b/gcc/testsuite/c-c++-common/pr51628-4.c
new file mode 100644
index 00000000000..c4c1fb72d6d
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/pr51628-4.c
@@ -0,0 +1,35 @@
+/* PR c/51628. */
+/* { dg-do compile } */
+/* { dg-options "-O" } */
+
+struct pair_t
+{
+ int x;
+ int i;
+} __attribute__((packed));
+
+extern struct pair_t p;
+extern int *x;
+extern void bar (int *);
+
+int *addr = &p.i;
+/* { dg-warning "may result in an unaligned pointer value" "" { target *-*-* }
.-1 } */
+
+int *
+foo (void)
+{
+ struct pair_t arr[2] = { { 1, 10 }, { 2, 20 } };
+ int *p0, *p1;
+ p0 = &arr[0].i;
+/* { dg-warning "may result in an unaligned pointer value" "" { target *-*-* }
.-1 } */
+ bar (p0);
+ p1 = &arr[1].i;
+/* { dg-warning "may result in an unaligned pointer value" "" { target *-*-* }
.-1 } */
+ bar (p1);
+ bar (&p.i);
+/* { dg-warning "may result in an unaligned pointer value" "" { target *-*-* }
.-1 } */
+ x = &p.i;
+/* { dg-warning "may result in an unaligned pointer value" "" { target *-*-* }
.-1 } */
+ return &p.i;
+/* { dg-warning "may result in an unaligned pointer value" "" { target *-*-* }
.-1 } */
+}
diff --git a/gcc/testsuite/c-c++-common/pr51628-5.c
b/gcc/testsuite/c-c++-common/pr51628-5.c
new file mode 100644
index 00000000000..9d7c309a0ef
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/pr51628-5.c
@@ -0,0 +1,35 @@
+/* PR c/51628. */
+/* { dg-do compile } */
+/* { dg-options "-O" } */
+
+struct pair_t
+{
+ char x;
+ int i;
+} __attribute__((packed));
+
+extern struct pair_t p;
+extern int *x;
+extern void bar (int *);
+
+int *addr = &p.i;
+/* { dg-warning "may result in an unaligned pointer value" "" { target *-*-* }
.-1 } */
+
+int *
+foo (void)
+{
+ struct pair_t arr[2] = { { 1, 10 }, { 2, 20 } };
+ int *p0, *p1;
+ p0 = &arr[0].i;
+/* { dg-warning "may result in an unaligned pointer value" "" { target *-*-* }
.-1 } */
+ bar (p0);
+ p1 = &arr[1].i;
+/* { dg-warning "may result in an unaligned pointer value" "" { target *-*-* }
.-1 } */
+ bar (p1);
+ bar (&p.i);
+/* { dg-warning "may result in an unaligned pointer value" "" { target *-*-* }
.-1 } */
+ x = &p.i;
+/* { dg-warning "may result in an unaligned pointer value" "" { target *-*-* }
.-1 } */
+ return &p.i;
+/* { dg-warning "may result in an unaligned pointer value" "" { target *-*-* }
.-1 } */
+}
diff --git a/gcc/testsuite/c-c++-common/pr51628-6.c
b/gcc/testsuite/c-c++-common/pr51628-6.c
new file mode 100644
index 00000000000..52aa07a4cf3
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/pr51628-6.c
@@ -0,0 +1,35 @@
+/* PR c/51628. */
+/* { dg-do compile } */
+/* { dg-options "-O" } */
+
+struct pair_t
+{
+ char x;
+ int i;
+} __attribute__((packed, aligned (4)));
+
+extern struct pair_t p;
+extern int *x;
+extern void bar (int *);
+
+int *addr = &p.i;
+/* { dg-warning "may result in an unaligned pointer value" "" { target *-*-* }
.-1 } */
+
+int *
+foo (void)
+{
+ struct pair_t arr[2] = { { 1, 10 }, { 2, 20 } };
+ int *p0, *p1;
+ p0 = &arr[0].i;
+/* { dg-warning "may result in an unaligned pointer value" "" { target *-*-* }
.-1 } */
+ bar (p0);
+ p1 = &arr[1].i;
+/* { dg-warning "may result in an unaligned pointer value" "" { target *-*-* }
.-1 } */
+ bar (p1);
+ bar (&p.i);
+/* { dg-warning "may result in an unaligned pointer value" "" { target *-*-* }
.-1 } */
+ x = &p.i;
+/* { dg-warning "may result in an unaligned pointer value" "" { target *-*-* }
.-1 } */
+ return &p.i;
+/* { dg-warning "may result in an unaligned pointer value" "" { target *-*-* }
.-1 } */
+}
diff --git a/gcc/testsuite/c-c++-common/ubsan/align-2.c
b/gcc/testsuite/c-c++-common/ubsan/align-2.c
index 071de8c202a..336b1c3c907 100644
--- a/gcc/testsuite/c-c++-common/ubsan/align-2.c
+++ b/gcc/testsuite/c-c++-common/ubsan/align-2.c
@@ -1,6 +1,6 @@
/* Limit this to known non-strict alignment targets. */
/* { dg-do run { target { i?86-*-linux* x86_64-*-linux* } } } */
-/* { dg-options "-fsanitize=alignment" } */
+/* { dg-options "-fsanitize=alignment -Wno-address-of-packed-member" } */
struct S { int a; char b; long long c; short d[10]; };
struct T { char a; long long b; };
diff --git a/gcc/testsuite/c-c++-common/ubsan/align-4.c
b/gcc/testsuite/c-c++-common/ubsan/align-4.c
index 3252595d330..d5feeee29c6 100644
--- a/gcc/testsuite/c-c++-common/ubsan/align-4.c
+++ b/gcc/testsuite/c-c++-common/ubsan/align-4.c
@@ -1,6 +1,6 @@
/* Limit this to known non-strict alignment targets. */
/* { dg-do run { target { i?86-*-linux* x86_64-*-linux* } } } */
-/* { dg-options "-fsanitize=null,alignment" } */
+/* { dg-options "-fsanitize=null,alignment -Wno-address-of-packed-member" } */
#include "align-2.c"
diff --git a/gcc/testsuite/c-c++-common/ubsan/align-6.c
b/gcc/testsuite/c-c++-common/ubsan/align-6.c
index 3364746fb27..0302b7b8894 100644
--- a/gcc/testsuite/c-c++-common/ubsan/align-6.c
+++ b/gcc/testsuite/c-c++-common/ubsan/align-6.c
@@ -1,6 +1,6 @@
/* Limit this to known non-strict alignment targets. */
/* { dg-do run { target { i?86-*-linux* x86_64-*-linux* } } } */
-/* { dg-options "-O -fsanitize=alignment -fsanitize-recover=alignment" } */
+/* { dg-options "-O -fsanitize=alignment -fsanitize-recover=alignment
-Wno-address-of-packed-member" } */
struct S { int a; char b; long long c; short d[10]; };
struct T { char a; long long b; };
diff --git a/gcc/testsuite/c-c++-common/ubsan/align-7.c
b/gcc/testsuite/c-c++-common/ubsan/align-7.c
index ec4e87f56d5..dd1e8c91cef 100644
--- a/gcc/testsuite/c-c++-common/ubsan/align-7.c
+++ b/gcc/testsuite/c-c++-common/ubsan/align-7.c
@@ -1,6 +1,6 @@
/* Limit this to known non-strict alignment targets. */
/* { dg-do run { target { i?86-*-linux* x86_64-*-linux* } } } */
-/* { dg-options "-O -fsanitize=alignment -fno-sanitize-recover=alignment
-fdump-tree-sanopt-details" } */
+/* { dg-options "-O -fsanitize=alignment -fno-sanitize-recover=alignment
-Wno-address-of-packed-member -fdump-tree-sanopt-details" } */
/* { dg-skip-if "" { *-*-* } { "-flto -fno-fat-lto-objects" } } */
/* { dg-shouldfail "ubsan" } */
diff --git a/gcc/testsuite/c-c++-common/ubsan/align-8.c
b/gcc/testsuite/c-c++-common/ubsan/align-8.c
index 61c1ceb6682..5fe0e0fe931 100644
--- a/gcc/testsuite/c-c++-common/ubsan/align-8.c
+++ b/gcc/testsuite/c-c++-common/ubsan/align-8.c
@@ -1,6 +1,6 @@
/* Limit this to known non-strict alignment targets. */
/* { dg-do run { target { i?86-*-linux* x86_64-*-linux* } } } */
-/* { dg-options "-O -fsanitize=alignment -fsanitize-undefined-trap-on-error
-fdump-tree-sanopt-details" } */
+/* { dg-options "-O -fsanitize=alignment -fsanitize-undefined-trap-on-error
-Wno-address-of-packed-member -fdump-tree-sanopt-details" } */
/* { dg-skip-if "" { *-*-* } { "-flto -fno-fat-lto-objects" } } */
/* { dg-shouldfail "ubsan" } */
diff --git a/gcc/testsuite/g++.dg/ubsan/align-2.C
b/gcc/testsuite/g++.dg/ubsan/align-2.C
index 3e4f5485d02..c97ede88392 100644
--- a/gcc/testsuite/g++.dg/ubsan/align-2.C
+++ b/gcc/testsuite/g++.dg/ubsan/align-2.C
@@ -1,6 +1,6 @@
// Limit this to known non-strict alignment targets.
// { dg-do run { target { i?86-*-linux* x86_64-*-linux* } } }
-// { dg-options "-fsanitize=alignment -Wall -Wno-unused-variable -std=c++11" }
+// { dg-options "-fsanitize=alignment -Wall -Wno-unused-variable
-Wno-address-of-packed-member -std=c++11" }
typedef const long int L;
struct S { long int l; char buf[1 + sizeof (int) + sizeof (L)]; } s;
--
2.14.3
