On Thu, May 17, 2018 at 10:32:56AM -0700, H.J. Lu wrote:
> On Mon, May 14, 2018 at 8:00 PM, Martin Sebor <mse...@gmail.com> wrote:
> > On 05/14/2018 01:10 PM, H.J. Lu wrote:
> >>
> >> On Mon, May 14, 2018 at 10:40 AM, H.J. Lu <hjl.to...@gmail.com> wrote:
> >>
> >>>>>> $ cat c.i
> >>>>>> struct B { int i; };
> >>>>>> struct C { struct B b; } __attribute__ ((packed));
> >>>>>>
> >>>>>> long* g8 (struct C *p) { return p; }
> >>>>>> $ gcc -O2 -S c.i -Wno-incompatible-pointer-types
> >>>>>> c.i: In function ‘g8’:
> >>>>>> c.i:4:33: warning: taking value of packed 'struct C *' may result in
> >>>>>> an
> >>>>>> unaligned pointer value [-Waddress-of-packed-member]
> >>>>
> >>>>
> >>>> ^^^^^
> >>>> That should read "taking address" (not value) but...
> >>>
> >>>
> >>> The value of 'struct C *' is an address. There is no address taken here.
> >>>
> >>>> ...to help explain the problem I would suggest to mention the expected
> >>>> and actual alignment in the warning message. E.g.,
> >>>>
> >>>> storing the address of a packed 'struct C' in 'struct C *' increases
> >>>> the
> >>>> alignment of the pointer from 1 to 4.
> >>>
> >>>
> >>> I will take a look.
> >>>
> >>>> (IIUC, the source type and destination type need not be the same so
> >>>> including both should be helpful in those cases.)
> >>>>
> >>>> Adding a note pointing to the declaration of either the struct or
> >>>> the member would help users find it if it's a header far removed
> >>>> from the point of use.
> >>>
> >>>
> >>> I will see what I can do.
> >>
> >>
> >> How about this
> >>
> >> [hjl@gnu-skx-1 pr51628]$ cat n9.i
> >> struct B { int i; };
> >> struct C { struct B b; } __attribute__ ((packed));
> >>
> >> long* g8 (struct C *p) { return p; }
> >> [hjl@gnu-skx-1 pr51628]$
> >> /export/build/gnu/gcc-test/build-x86_64-linux/gcc/xgcc
> >> -B/export/build/gnu/gcc-test/build-x86_64-linux/gcc/ -O2 -S n9.i
> >> n9.i: In function ‘g8’:
> >> n9.i:4:33: warning: returning ‘struct C *’ from a function with
> >> incompatible return type ‘long int *’ [-Wincompatible-pointer-types]
> >> long* g8 (struct C *p) { return p; }
> >> ^
> >> n9.i:4:33: warning: taking value of packed ‘struct C *’ increases the
> >> alignment of the pointer from 1 to 8 [-Waddress-of-packed-member]
> >> n9.i:2:8: note: defined here
> >> struct C { struct B b; } __attribute__ ((packed));
> >
> >
> > Mentioning the alignments looks good.
> >
> > I still find the "taking value" phrasing odd. I think we would
> > describe what's going on as "converting a pointer to a packed C
> > to a pointer to C (with an alignment of 8)" so I'd suggest to
> > use the term converting instead.
>
> How about this?
>
> [hjl@gnu-skx-1 pr51628]$ cat n12.i
> struct B { int i; };
> struct C { struct B b; } __attribute__ ((packed));
>
> struct B* g8 (struct C *p) { return p; }
> [hjl@gnu-skx-1 pr51628]$ make n12.s
> /export/build/gnu/gcc-test/build-x86_64-linux/gcc/xgcc
> -B/export/build/gnu/gcc-test/build-x86_64-linux/gcc/ -O2 -S n12.i
> n12.i: In function ‘g8’:
> n12.i:4:37: warning: returning ‘struct C *’ from a function with
> incompatible return type ‘struct B *’ [-Wincompatible-pointer-types]
> struct B* g8 (struct C *p) { return p; }
> ^
> n12.i:4:37: warning: converting a pointer to packed ‘struct C *’
> increases the alignment of the pointer to ‘struct B *’ from 1 to 4
> [-Waddress-of-packed-member]
> n12.i:2:8: note: defined here
> struct C { struct B b; } __attribute__ ((packed));
> ^
> n12.i:1:8: note: defined here
> struct B { int i; };
> ^
> [hjl@gnu-skx-1 pr51628]$
>
> > I also think mentioning both the source and the destination types
> > is useful irrespective of -Wincompatible-pointer-types because
> > the latter is often suppressed using a cast, as in:
> >
> > struct __attribute__ ((packed)) A { int i; };
> > struct B {
> > struct A a;
> > } b;
> >
> > long *p = (long*)&b.a.i; // -Waddress-of-packed-member
> > int *q = (int*)&b.a; // missing warning
> >
> > If the types above were obfuscated by macros, typedefs, or in
> > C++ template parameters, it could be difficult to figure out
> > what the type of the member is because neither it nor the name
> > of the member appears in the message.
>
> How about this
>
> [hjl@gnu-skx-1 pr51628]$ cat n13.i
> struct __attribute__ ((packed)) A { int i; };
> struct B {
> struct A a;
> } b;
>
> long *p = (long*)&b.a.i;
> int *q = (int*)&b.a;
> [hjl@gnu-skx-1 pr51628]$ make n13.s
> /export/build/gnu/gcc-test/build-x86_64-linux/gcc/xgcc
> -B/export/build/gnu/gcc-test/build-x86_64-linux/gcc/ -O2 -S n13.i
> n13.i:6:18: warning: taking address of packed member of ‘struct A’ may
> result in an unaligned pointer value [-Waddress-of-packed-member]
> long *p = (long*)&b.a.i;
> ^~~~~~
> n13.i:7:16: warning: taking address of packed member of ‘struct B’ may
> result in an unaligned pointer value [-Waddress-of-packed-member]
> int *q = (int*)&b.a;
> ^~~~
> [hjl@gnu-skx-1 pr51628]$
>
>
Here is the updated patch. OK for trunk?
H.J.
----
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 check alignment at pointer assignment and warn unaligned address as
well as unaligned pointer:
$ 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: taking address of packed member of 'struct pair_t' may
result in an unaligned pointer value [-Waddress-of-packed-member]
int *addr = &p.i;
^
$ cat c.i
struct B { int i; };
struct C { struct B b; } __attribute__ ((packed));
long* g8 (struct C *p) { return p; }
$ gcc -O2 -S c.i -Wno-incompatible-pointer-types
c.i: In function ‘g8’:
c.i:4:33: warning: returning ‘struct C *’ from a function with incompatible
return type ‘long int *’ [-Wincompatible-pointer-types]
long* g8 (struct C *p) { return p; }
^
c.i:4:33: warning: converting a packed ‘struct C *’ pointer increases the
alignment of ‘long int *’ pointer from 1 to 8 [-Waddress-of-packed-member]
c.i:2:8: note: defined here
struct C { struct B b; } __attribute__ ((packed));
^
$
This warning is enabled by default. Since read_encoded_value_with_base
in unwind-pe.h has
union unaligned
{
void *ptr;
unsigned u2 __attribute__ ((mode (HI)));
unsigned u4 __attribute__ ((mode (SI)));
unsigned u8 __attribute__ ((mode (DI)));
signed s2 __attribute__ ((mode (HI)));
signed s4 __attribute__ ((mode (SI)));
signed s8 __attribute__ ((mode (DI)));
} __attribute__((__packed__));
_Unwind_Internal_Ptr result;
and GCC warns:
gcc/libgcc/unwind-pe.h:210:37: warning: taking address of packed member of
'union unaligned' may result in an unaligned pointer value
[-Waddress-of-packed-member]
result = (_Unwind_Internal_Ptr) u->ptr;
^
we need to add GCC pragma to ignore -Waddress-of-packed-member.
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 (check_address_of_packed_member): New function.
(warn_for_address_of_packed_member): Likewise.
* c.opt: Add -Wno-address-of-packed-member.
gcc/c/
PR c/51628
* c-typeck.c (warn_for_pointer_of_packed_member): New function.
(convert_for_assignment): Call warn_for_address_of_packed_member
and warn_for_pointer_of_packed_member.
gcc/cp/
PR c/51628
* call.c (convert_for_arg_passing): Call
warn_for_address_of_packed_member.
* typeck.c (convert_for_assignment): Likewise.
gcc/testsuite/
PR c/51628
* c-c++-common/pr51628-1.c: New test.
* 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/pr51628-7.c: Likewise.
* c-c++-common/pr51628-8.c: Likewise.
* c-c++-common/pr51628-9.c: Likewise.
* c-c++-common/pr51628-10.c: Likewise.
* c-c++-common/pr51628-11.c: Likewise.
* c-c++-common/pr51628-12.c: Likewise.
* c-c++-common/pr51628-13.c: Likewise.
* c-c++-common/pr51628-14.c: Likewise.
* c-c++-common/pr51628-15.c: Likewise.
* gcc.dg/pr51628-17.c: Likewise.
* gcc.dg/pr51628-18.c: Likewise.
* gcc.dg/pr51628-19.c: Likewise.
* gcc.dg/pr51628-20.c: Likewise.
* gcc.dg/pr51628-21.c: Likewise.
* gcc.dg/pr51628-22.c: Likewise.
* gcc.dg/pr51628-23.c: Likewise.
* gcc.dg/pr51628-24.c: Likewise.
* gcc.dg/pr51628-25.c: Likewise.
* c-c++-common/asan/misalign-1.c: Add
-Wno-address-of-packed-member.
* c-c++-common/asan/misalign-2.c: Likewise.
* c-c++-common/ubsan/align-2.c: Likewise.
* 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.
* c-c++-common/ubsan/align-10.c: Likewise.
* g++.dg/ubsan/align-2.C: Likewise.
* gcc.target/i386/avx512bw-vmovdqu16-2.c: Likewise.
* gcc.target/i386/avx512f-vmovdqu32-2.c: Likewise.
* gcc.target/i386/avx512f-vmovdqu64-2.c: Likewise.
* gcc.target/i386/avx512vl-vmovdqu16-2.c: Likewise.
* gcc.target/i386/avx512vl-vmovdqu32-2.c: Likewise.
* gcc.target/i386/avx512vl-vmovdqu64-2.c: Likewise.
libgcc/
* unwind-pe.h (read_encoded_value_with_base): Add GCC pragma
to ignore -Waddress-of-packed-member.
---
gcc/c-family/c-common.h | 1 +
gcc/c-family/c-warn.c | 119 ++++++++++++++++++
gcc/c-family/c.opt | 4 +
gcc/c/c-typeck.c | 64 +++++++++-
gcc/cp/call.c | 3 +
gcc/cp/typeck.c | 2 +
gcc/doc/invoke.texi | 11 +-
gcc/testsuite/c-c++-common/asan/misalign-1.c | 2 +-
gcc/testsuite/c-c++-common/asan/misalign-2.c | 2 +-
gcc/testsuite/c-c++-common/pr51628-1.c | 29 +++++
gcc/testsuite/c-c++-common/pr51628-10.c | 24 ++++
gcc/testsuite/c-c++-common/pr51628-11.c | 17 +++
gcc/testsuite/c-c++-common/pr51628-12.c | 18 +++
gcc/testsuite/c-c++-common/pr51628-13.c | 9 ++
gcc/testsuite/c-c++-common/pr51628-14.c | 9 ++
gcc/testsuite/c-c++-common/pr51628-15.c | 14 +++
gcc/testsuite/c-c++-common/pr51628-16.c | 13 ++
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/pr51628-7.c | 29 +++++
gcc/testsuite/c-c++-common/pr51628-8.c | 36 ++++++
gcc/testsuite/c-c++-common/pr51628-9.c | 36 ++++++
gcc/testsuite/c-c++-common/ubsan/align-10.c | 2 +-
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 +-
gcc/testsuite/gcc.dg/pr51628-17.c | 10 ++
gcc/testsuite/gcc.dg/pr51628-18.c | 23 ++++
gcc/testsuite/gcc.dg/pr51628-19.c | 26 ++++
gcc/testsuite/gcc.dg/pr51628-20.c | 11 ++
gcc/testsuite/gcc.dg/pr51628-21.c | 11 ++
gcc/testsuite/gcc.dg/pr51628-22.c | 9 ++
gcc/testsuite/gcc.dg/pr51628-23.c | 9 ++
gcc/testsuite/gcc.dg/pr51628-24.c | 10 ++
gcc/testsuite/gcc.dg/pr51628-25.c | 9 ++
.../gcc.target/i386/avx512bw-vmovdqu16-2.c | 2 +-
.../gcc.target/i386/avx512f-vmovdqu32-2.c | 2 +-
.../gcc.target/i386/avx512f-vmovdqu64-2.c | 2 +-
.../gcc.target/i386/avx512vl-vmovdqu16-2.c | 2 +-
.../gcc.target/i386/avx512vl-vmovdqu32-2.c | 2 +-
.../gcc.target/i386/avx512vl-vmovdqu64-2.c | 2 +-
libgcc/unwind-pe.h | 5 +
48 files changed, 742 insertions(+), 18 deletions(-)
create mode 100644 gcc/testsuite/c-c++-common/pr51628-1.c
create mode 100644 gcc/testsuite/c-c++-common/pr51628-10.c
create mode 100644 gcc/testsuite/c-c++-common/pr51628-11.c
create mode 100644 gcc/testsuite/c-c++-common/pr51628-12.c
create mode 100644 gcc/testsuite/c-c++-common/pr51628-13.c
create mode 100644 gcc/testsuite/c-c++-common/pr51628-14.c
create mode 100644 gcc/testsuite/c-c++-common/pr51628-15.c
create mode 100644 gcc/testsuite/c-c++-common/pr51628-16.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
create mode 100644 gcc/testsuite/c-c++-common/pr51628-7.c
create mode 100644 gcc/testsuite/c-c++-common/pr51628-8.c
create mode 100644 gcc/testsuite/c-c++-common/pr51628-9.c
create mode 100644 gcc/testsuite/gcc.dg/pr51628-17.c
create mode 100644 gcc/testsuite/gcc.dg/pr51628-18.c
create mode 100644 gcc/testsuite/gcc.dg/pr51628-19.c
create mode 100644 gcc/testsuite/gcc.dg/pr51628-20.c
create mode 100644 gcc/testsuite/gcc.dg/pr51628-21.c
create mode 100644 gcc/testsuite/gcc.dg/pr51628-22.c
create mode 100644 gcc/testsuite/gcc.dg/pr51628-23.c
create mode 100644 gcc/testsuite/gcc.dg/pr51628-24.c
create mode 100644 gcc/testsuite/gcc.dg/pr51628-25.c
diff --git a/gcc/c-family/c-common.h b/gcc/c-family/c-common.h
index c266fee74c7..9da96b2e944 100644
--- a/gcc/c-family/c-common.h
+++ b/gcc/c-family/c-common.h
@@ -1270,6 +1270,7 @@ extern void c_do_switch_warnings (splay_tree, location_t,
tree, tree, bool,
bool);
extern void warn_for_omitted_condop (location_t, tree);
extern bool warn_for_restrict (unsigned, tree *, unsigned);
+extern void warn_for_address_of_packed_member (tree, tree);
/* 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 2614eb58f14..f17223af48f 100644
--- a/gcc/c-family/c-warn.c
+++ b/gcc/c-family/c-warn.c
@@ -2587,3 +2587,122 @@ 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 value, RHS, takes the
+ unaligned address of packed member of struct or union when assigning
+ to TYPE. Otherwise, return NULL_TREE. */
+
+static tree
+check_address_of_packed_member (tree type, tree rhs)
+{
+ tree base;
+ tree object;
+ tree field;
+
+ if (INDIRECT_REF_P (rhs))
+ rhs = TREE_OPERAND (rhs, 0);
+
+ switch (TREE_CODE (rhs))
+ {
+ case ADDR_EXPR:
+ base = TREE_OPERAND (rhs, 0);
+ while (TREE_CODE (base) == ARRAY_REF)
+ base = TREE_OPERAND (base, 0);
+ if (TREE_CODE (base) != COMPONENT_REF)
+ return NULL_TREE;
+ object = TREE_OPERAND (base, 0);
+ field = TREE_OPERAND (base, 1);
+ break;
+ case COMPONENT_REF:
+ object = TREE_OPERAND (rhs, 0);
+ field = TREE_OPERAND (rhs, 1);
+ break;
+ default:
+ return NULL_TREE;
+ }
+
+ tree context;
+ unsigned int type_align, record_align;
+
+ /* Check alignment of the data member. */
+ if (TREE_CODE (field) == FIELD_DECL
+ && (DECL_PACKED (field)
+ || TYPE_PACKED (TREE_TYPE (field))))
+ {
+ /* Check the expected alignment against the field alignment. */
+ type_align = TYPE_ALIGN (type);
+ context = DECL_CONTEXT (field);
+ record_align = TYPE_ALIGN (context);
+ if ((record_align % type_align) != 0)
+ return context;
+ tree field_off = byte_position (field);
+ if (!multiple_of_p (TREE_TYPE (field_off), field_off,
+ size_int (type_align / BITS_PER_UNIT)))
+ return context;
+ }
+
+ /* Check alignment of the object. */
+ if (TREE_CODE (object) == COMPONENT_REF)
+ {
+ field = TREE_OPERAND (object, 1);
+ if (TREE_CODE (field) == FIELD_DECL && DECL_PACKED (field))
+ {
+ type_align = TYPE_ALIGN (type);
+ context = DECL_CONTEXT (field);
+ record_align = TYPE_ALIGN (context);
+ if ((record_align % type_align) != 0)
+ return context;
+ }
+ }
+
+ return NULL_TREE;
+}
+
+/* Warn if the right hand value, RHS, takes the unaligned address of
+ packed member of struct or union when assigning to TYPE. Otherwise,
+ return NULL_TREE. */
+
+void
+warn_for_address_of_packed_member (tree type, tree rhs)
+{
+ if (!warn_address_of_packed_member)
+ return;
+
+ /* Don't warn if we don't assign RHS to a pointer. */
+ if (!POINTER_TYPE_P (type))
+ return;
+
+ /* Get the type of the pointer pointing to. */
+ type = TREE_TYPE (type);
+
+ if (TREE_CODE (rhs) == NOP_EXPR)
+ rhs = TREE_OPERAND (rhs, 0);
+
+ tree context;
+
+ if (TREE_CODE (rhs) == COND_EXPR)
+ {
+ /* Check the THEN path first. */
+ tree op1 = TREE_OPERAND (rhs, 1);
+ context = check_address_of_packed_member (type, op1);
+ if (context)
+ rhs = op1;
+ else
+ {
+ /* Check the ELSE path. */
+ rhs = TREE_OPERAND (rhs, 2);
+ context = check_address_of_packed_member (type, rhs);
+ }
+ }
+ else
+ context = check_address_of_packed_member (type, rhs);
+
+ if (context)
+ {
+ location_t loc = EXPR_LOC_OR_LOC (rhs, input_location);
+ warning_at (loc, OPT_Waddress_of_packed_member,
+ "taking address of packed member of %qT may result "
+ "in an unaligned pointer value",
+ context);
+ }
+}
diff --git a/gcc/c-family/c.opt b/gcc/c-family/c.opt
index c48d6dced8d..9db4c9dba8a 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 45a4529ed52..fe5198b0eb0 100644
--- a/gcc/c/c-typeck.c
+++ b/gcc/c/c-typeck.c
@@ -6289,6 +6289,58 @@ inform_for_arg (tree fundecl, location_t ploc, int
parmnum,
expected_type, actual_type);
}
+/* Warn if the right hand poiner value RHS isn't aligned to a
+ pointer type TYPE at LOCATION. */
+
+static void
+warn_for_pointer_of_packed_member (location_t location, tree type,
+ tree rhs)
+{
+ if (!warn_address_of_packed_member || !POINTER_TYPE_P (type))
+ return;
+
+ bool pointer_p;
+ tree rhstype;
+
+ /* Check the original type of LHS. */
+ switch (TREE_CODE (rhs))
+ {
+ case PARM_DECL:
+ case VAR_DECL:
+ rhstype = TREE_TYPE (rhs);
+ pointer_p = POINTER_TYPE_P (rhstype);
+ break;
+ case NOP_EXPR:
+ rhs = TREE_OPERAND (rhs, 0);
+ if (TREE_CODE (rhs) == ADDR_EXPR)
+ rhs = TREE_OPERAND (rhs, 0);
+ rhstype = TREE_TYPE (rhs);
+ pointer_p = TREE_CODE (rhstype) == ARRAY_TYPE;
+ break;
+ default:
+ return;
+ }
+
+ if (pointer_p
+ && TYPE_PACKED (TREE_TYPE (rhstype)))
+ {
+ unsigned int type_align = TYPE_ALIGN_UNIT (TREE_TYPE (type));
+ unsigned int rhs_align = TYPE_ALIGN_UNIT (TREE_TYPE (rhstype));
+ if ((rhs_align % type_align) != 0)
+ {
+ warning_at (location, OPT_Waddress_of_packed_member,
+ "converting a packed %qT pointer increases the "
+ "alignment of %qT pointer from %d to %d",
+ rhstype, type, rhs_align, type_align);
+ tree decl = TYPE_STUB_DECL (TREE_TYPE (rhstype));
+ inform (DECL_SOURCE_LOCATION (decl), "defined here");
+ decl = TYPE_STUB_DECL (TREE_TYPE (type));
+ if (decl)
+ inform (DECL_SOURCE_LOCATION (decl), "defined here");
+ }
+ }
+}
+
/* Convert value RHS to type TYPE as preparation for an assignment to
an lvalue of type TYPE. If ORIGTYPE is not NULL_TREE, it is the
original type of RHS; this differs from TREE_TYPE (RHS) for enum
@@ -6499,7 +6551,10 @@ convert_for_assignment (location_t location, location_t
expr_loc, tree type,
}
if (TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (rhstype))
- return rhs;
+ {
+ warn_for_address_of_packed_member (type, orig_rhs);
+ return rhs;
+ }
if (coder == VOID_TYPE)
{
@@ -6986,6 +7041,13 @@ convert_for_assignment (location_t location, location_t
expr_loc, tree type,
}
}
+ /* If RHS is't an address, check pointer or array of packed
+ struct or union. */
+ if (TREE_CODE (orig_rhs) != ADDR_EXPR)
+ warn_for_pointer_of_packed_member (location, type, orig_rhs);
+ else
+ warn_for_address_of_packed_member (type, orig_rhs);
+
return convert (type, rhs);
}
else if (codel == POINTER_TYPE && coder == ARRAY_TYPE)
diff --git a/gcc/cp/call.c b/gcc/cp/call.c
index 4d04785f2b9..39045d74566 100644
--- a/gcc/cp/call.c
+++ b/gcc/cp/call.c
@@ -7425,6 +7425,9 @@ convert_for_arg_passing (tree type, tree val,
tsubst_flags_t complain)
}
maybe_warn_parm_abi (type, EXPR_LOC_OR_LOC (val, input_location));
}
+
+ warn_for_address_of_packed_member (type, val);
+
return val;
}
diff --git a/gcc/cp/typeck.c b/gcc/cp/typeck.c
index ecb334d19d2..ca0ccc77612 100644
--- a/gcc/cp/typeck.c
+++ b/gcc/cp/typeck.c
@@ -8904,6 +8904,8 @@ convert_for_assignment (tree type, tree rhs,
TREE_NO_WARNING (rhs) = 1;
}
+ warn_for_address_of_packed_member (type, rhs);
+
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 4023197c07c..90cbfb7e775 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
@@ -6441,6 +6441,13 @@ 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/asan/misalign-1.c
b/gcc/testsuite/c-c++-common/asan/misalign-1.c
index 5cd605ac045..ebeb0306706 100644
--- a/gcc/testsuite/c-c++-common/asan/misalign-1.c
+++ b/gcc/testsuite/c-c++-common/asan/misalign-1.c
@@ -1,5 +1,5 @@
/* { dg-do run { target { ilp32 || lp64 } } } */
-/* { dg-skip-if "" { *-*-* } { "*" } { "-O2" } } */
+/* { dg-skip-if "" { *-*-* } { "*" } { "-O2 -Wno-address-of-packed-member" }
} */
/* { dg-additional-options "-fno-omit-frame-pointer" { target *-*-darwin* } }
*/
/* { dg-shouldfail "asan" } */
diff --git a/gcc/testsuite/c-c++-common/asan/misalign-2.c
b/gcc/testsuite/c-c++-common/asan/misalign-2.c
index a6ed49bac05..b27e22d35a8 100644
--- a/gcc/testsuite/c-c++-common/asan/misalign-2.c
+++ b/gcc/testsuite/c-c++-common/asan/misalign-2.c
@@ -1,5 +1,5 @@
/* { dg-do run { target { ilp32 || lp64 } } } */
-/* { dg-skip-if "" { *-*-* } { "*" } { "-O2" } } */
+/* { dg-skip-if "" { *-*-* } { "*" } { "-O2 -Wno-address-of-packed-member" }
} */
/* { dg-additional-options "-fno-omit-frame-pointer" { target *-*-darwin* } }
*/
/* { dg-shouldfail "asan" } */
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/pr51628-10.c
b/gcc/testsuite/c-c++-common/pr51628-10.c
new file mode 100644
index 00000000000..085fe1608c4
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/pr51628-10.c
@@ -0,0 +1,24 @@
+/* PR c/51628. */
+/* { dg-do run { target int128 } } */
+/* { dg-options "-O2" } */
+
+struct pair_t
+{
+ char c;
+ __int128_t i;
+} __attribute__ ((packed));
+
+typedef struct unaligned_int128_t_
+{
+ __int128_t value;
+} __attribute__((packed)) unaligned_int128_t;
+
+struct pair_t p = {0, 1};
+unaligned_int128_t *addr = (unaligned_int128_t *) &p.i;
+
+int
+main()
+{
+ addr->value = ~(__int128_t)0;
+ return (p.i != 1) ? 0 : 1;
+}
diff --git a/gcc/testsuite/c-c++-common/pr51628-11.c
b/gcc/testsuite/c-c++-common/pr51628-11.c
new file mode 100644
index 00000000000..7661232ac88
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/pr51628-11.c
@@ -0,0 +1,17 @@
+/* PR c/51628. */
+/* { dg-do compile { target int128 } } */
+/* { dg-options "-O" } */
+
+struct tuple_t
+{
+ char c[12];
+ __int128_t i;
+} __attribute__((packed, aligned (8)));
+
+typedef struct unaligned_int128_t_
+{
+ __int128_t value;
+} __attribute__ ((packed, aligned(4))) unaligned_int128_t;
+
+struct tuple_t p = {{0}, 1};
+unaligned_int128_t *addr = (unaligned_int128_t *)(&p.i);
diff --git a/gcc/testsuite/c-c++-common/pr51628-12.c
b/gcc/testsuite/c-c++-common/pr51628-12.c
new file mode 100644
index 00000000000..bc221fa87ef
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/pr51628-12.c
@@ -0,0 +1,18 @@
+/* PR c/51628. */
+/* { dg-do compile { target int128 } } */
+/* { dg-options "-O" } */
+
+struct tuple_t
+{
+ char c[10];
+ __int128_t i;
+} __attribute__((packed, aligned (8)));
+
+typedef struct unaligned_int128_t_
+{
+ __int128_t value;
+} __attribute__ ((packed, aligned(4))) unaligned_int128_t;
+
+struct tuple_t p = {{0}, 1};
+unaligned_int128_t *addr = (unaligned_int128_t *)(&p.i);
+/* { dg-warning "may result in an unaligned pointer value" "" { target *-*-* }
.-1 } */
diff --git a/gcc/testsuite/c-c++-common/pr51628-13.c
b/gcc/testsuite/c-c++-common/pr51628-13.c
new file mode 100644
index 00000000000..0edd5e7f84d
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/pr51628-13.c
@@ -0,0 +1,9 @@
+/* PR c/51628. */
+/* { dg-do compile } */
+/* { dg-options "-O" } */
+
+struct B { int i; };
+struct C { struct B b; } __attribute__ ((packed));
+
+int* h4 (struct C *p) { return &p->b.i; }
+/* { dg-warning "may result in an unaligned pointer value" "" { target *-*-* }
.-1 } */
diff --git a/gcc/testsuite/c-c++-common/pr51628-14.c
b/gcc/testsuite/c-c++-common/pr51628-14.c
new file mode 100644
index 00000000000..f50378b8651
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/pr51628-14.c
@@ -0,0 +1,9 @@
+/* PR c/51628. */
+/* { dg-do compile } */
+/* { dg-options "-O" } */
+
+struct A {
+ int i;
+} __attribute__ ((packed));
+
+void* f0 (struct A *p) { return &p->i; }
diff --git a/gcc/testsuite/c-c++-common/pr51628-15.c
b/gcc/testsuite/c-c++-common/pr51628-15.c
new file mode 100644
index 00000000000..bcac6d70ad5
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/pr51628-15.c
@@ -0,0 +1,14 @@
+/* PR c/51628. */
+/* { dg-do compile } */
+/* { dg-options "-O" } */
+
+struct A {
+ int i;
+} __attribute__ ((packed));
+
+int*
+f (struct A *p, int *q)
+{
+ return q ? q : &p->i;
+/* { dg-warning "may result in an unaligned pointer value" "" { target *-*-* }
.-1 } */
+}
diff --git a/gcc/testsuite/c-c++-common/pr51628-16.c
b/gcc/testsuite/c-c++-common/pr51628-16.c
new file mode 100644
index 00000000000..cd502fe76b8
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/pr51628-16.c
@@ -0,0 +1,13 @@
+/* PR c/51628. */
+/* { dg-do compile } */
+/* { dg-options "-O" } */
+
+struct __attribute__ ((packed)) A { int i; };
+struct B {
+ struct A a;
+} b;
+
+int *p = (int*)&b.a.i;
+/* { dg-warning "may result in an unaligned pointer value" "" { target *-*-* }
.-1 } */
+int *q = (int*)&b.a;
+/* { dg-warning "may result in an unaligned pointer value" "" { target *-*-* }
.-1 } */
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/pr51628-7.c
b/gcc/testsuite/c-c++-common/pr51628-7.c
new file mode 100644
index 00000000000..ae4a681f966
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/pr51628-7.c
@@ -0,0 +1,29 @@
+/* PR c/51628. */
+/* { dg-do compile } */
+/* { dg-options "-O" } */
+
+struct pair_t
+{
+ int x;
+ int i[4];
+} __attribute__((packed, aligned (4)));
+
+extern struct pair_t p;
+extern int *x;
+extern void bar (int *);
+
+int *addr = p.i;
+
+int *
+foo (struct pair_t *p)
+{
+ int *p0, *p1;
+ p0 = p->i;
+ bar (p0);
+ p1 = &p->i[1];
+ bar (p1);
+ bar (p->i);
+ bar (&p->i[2]);
+ x = p->i;
+ return &p->i[3];
+}
diff --git a/gcc/testsuite/c-c++-common/pr51628-8.c
b/gcc/testsuite/c-c++-common/pr51628-8.c
new file mode 100644
index 00000000000..cc2dae096ae
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/pr51628-8.c
@@ -0,0 +1,36 @@
+/* PR c/51628. */
+/* { dg-do compile } */
+/* { dg-options "-O" } */
+
+struct pair_t
+{
+ char x;
+ int i[4];
+} __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 (struct pair_t *p)
+{
+ int *p0, *p1;
+ p0 = p->i;
+/* { dg-warning "may result in an unaligned pointer value" "" { target *-*-* }
.-1 } */
+ bar (p0);
+ p1 = &p->i[1];
+/* { 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 } */
+ bar (&p->i[2]);
+/* { 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[3];
+/* { dg-warning "may result in an unaligned pointer value" "" { target *-*-* }
.-1 } */
+}
diff --git a/gcc/testsuite/c-c++-common/pr51628-9.c
b/gcc/testsuite/c-c++-common/pr51628-9.c
new file mode 100644
index 00000000000..0470aa3b93d
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/pr51628-9.c
@@ -0,0 +1,36 @@
+/* PR c/51628. */
+/* { dg-do compile } */
+/* { dg-options "-O" } */
+
+struct pair_t
+{
+ int x;
+ int i[4];
+} __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 (struct pair_t *p)
+{
+ int *p0, *p1;
+ p0 = p->i;
+/* { dg-warning "may result in an unaligned pointer value" "" { target *-*-* }
.-1 } */
+ bar (p0);
+ p1 = &p->i[1];
+/* { 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 } */
+ bar (&p->i[2]);
+/* { 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[3];
+/* { dg-warning "may result in an unaligned pointer value" "" { target *-*-* }
.-1 } */
+}
diff --git a/gcc/testsuite/c-c++-common/ubsan/align-10.c
b/gcc/testsuite/c-c++-common/ubsan/align-10.c
index 56ae9ebfe30..6210533173c 100644
--- a/gcc/testsuite/c-c++-common/ubsan/align-10.c
+++ b/gcc/testsuite/c-c++-common/ubsan/align-10.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 R { int a; } r;
struct S { struct R a; char b; long long c; short d[10]; };
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;
diff --git a/gcc/testsuite/gcc.dg/pr51628-17.c
b/gcc/testsuite/gcc.dg/pr51628-17.c
new file mode 100644
index 00000000000..0be95b2294e
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr51628-17.c
@@ -0,0 +1,10 @@
+/* PR c/51628. */
+/* { dg-do compile } */
+/* { dg-options "-O -Wno-incompatible-pointer-types" } */
+
+struct A {
+ int i;
+} __attribute__ ((packed));
+
+long* f8 (struct A *p) { return &p->i; }
+/* { dg-warning "may result in an unaligned pointer value" "" { target *-*-* }
.-1 } */
diff --git a/gcc/testsuite/gcc.dg/pr51628-18.c
b/gcc/testsuite/gcc.dg/pr51628-18.c
new file mode 100644
index 00000000000..03a04eff75c
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr51628-18.c
@@ -0,0 +1,23 @@
+/* PR c/51628. */
+/* { dg-do compile } */
+/* { dg-options "-O" } */
+
+void foo (int *);
+
+int *
+bar (int n, int k, void *ptr)
+{
+ struct A
+ {
+ int c[k];
+ int x[n];
+ } __attribute__ ((packed, aligned (4)));
+ struct A *p = (struct A *) ptr;
+
+ int *p0, *p1;
+ p0 = p->x;
+ foo (p0);
+ p1 = &p->x[1];
+ foo (p1);
+ return &p->x[1];
+}
diff --git a/gcc/testsuite/gcc.dg/pr51628-19.c
b/gcc/testsuite/gcc.dg/pr51628-19.c
new file mode 100644
index 00000000000..7ff03e85cea
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr51628-19.c
@@ -0,0 +1,26 @@
+/* PR c/51628. */
+/* { dg-do compile } */
+/* { dg-options "-O" } */
+
+void foo (int *);
+
+int *
+bar (int n, int k, void *ptr)
+{
+ struct A
+ {
+ char c[k];
+ int x[n];
+ } __attribute__ ((packed));
+ struct A *p = (struct A *) ptr;
+
+ int *p0, *p1;
+ p0 = p->x;
+/* { dg-warning "may result in an unaligned pointer value" "" { target *-*-* }
.-1 } */
+ foo (p0);
+ p1 = &p->x[1];
+/* { dg-warning "may result in an unaligned pointer value" "" { target *-*-* }
.-1 } */
+ foo (p1);
+ return &p->x[1];
+/* { dg-warning "may result in an unaligned pointer value" "" { target *-*-* }
.-1 } */
+}
diff --git a/gcc/testsuite/gcc.dg/pr51628-20.c
b/gcc/testsuite/gcc.dg/pr51628-20.c
new file mode 100644
index 00000000000..7d7865313c2
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr51628-20.c
@@ -0,0 +1,11 @@
+/* PR c/51628. */
+/* { dg-do compile } */
+/* { dg-options "-O -Wno-incompatible-pointer-types" } */
+
+struct B { int i; };
+struct C { struct B b; } __attribute__ ((packed));
+
+extern struct C *p;
+
+long* g8 (void) { return p; }
+/* { dg-warning "increases the alignment of '.*' pointer from 1 to " "" {
target *-*-* } .-1 } */
diff --git a/gcc/testsuite/gcc.dg/pr51628-21.c
b/gcc/testsuite/gcc.dg/pr51628-21.c
new file mode 100644
index 00000000000..7fdcdaed77d
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr51628-21.c
@@ -0,0 +1,11 @@
+/* PR c/51628. */
+/* { dg-do compile } */
+/* { dg-options "-O -Wno-incompatible-pointer-types" } */
+
+struct B { int i; };
+struct C { struct B b; } __attribute__ ((packed));
+
+extern struct C p[];
+
+long* g8 (void) { return p; }
+/* { dg-warning "increases the alignment of '.*' pointer from 1 to " "" {
target *-*-* } .-1 } */
diff --git a/gcc/testsuite/gcc.dg/pr51628-22.c
b/gcc/testsuite/gcc.dg/pr51628-22.c
new file mode 100644
index 00000000000..1bd5d791639
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr51628-22.c
@@ -0,0 +1,9 @@
+/* PR c/51628. */
+/* { dg-do compile } */
+/* { dg-options "-O -Wno-incompatible-pointer-types" } */
+
+struct B { int i; };
+struct C { struct B b; } __attribute__ ((packed));
+
+int* g4 (struct C *p) { return &p->b; }
+/* { dg-warning "may result in an unaligned pointer value" "" { target *-*-* }
.-1 } */
diff --git a/gcc/testsuite/gcc.dg/pr51628-23.c
b/gcc/testsuite/gcc.dg/pr51628-23.c
new file mode 100644
index 00000000000..5709be60ac8
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr51628-23.c
@@ -0,0 +1,9 @@
+/* PR c/51628. */
+/* { dg-do compile } */
+/* { dg-options "-O -Wno-incompatible-pointer-types" } */
+
+struct A {
+ int i;
+} __attribute__ ((packed));
+
+char* f0 (struct A *p) { return &p->i; }
diff --git a/gcc/testsuite/gcc.dg/pr51628-24.c
b/gcc/testsuite/gcc.dg/pr51628-24.c
new file mode 100644
index 00000000000..3ad99cd2f16
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr51628-24.c
@@ -0,0 +1,10 @@
+/* PR c/51628. */
+/* { dg-do compile } */
+/* { dg-options "-O -Wno-incompatible-pointer-types" } */
+
+struct A {
+ int i;
+} __attribute__ ((packed));
+
+short* f2 (struct A *p) { return &p->i; }
+/* { dg-warning "may result in an unaligned pointer value" "" { target *-*-* }
.-1 } */
diff --git a/gcc/testsuite/gcc.dg/pr51628-25.c
b/gcc/testsuite/gcc.dg/pr51628-25.c
new file mode 100644
index 00000000000..6bd78a8811c
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr51628-25.c
@@ -0,0 +1,9 @@
+/* PR c/51628. */
+/* { dg-do compile } */
+/* { dg-options "-O -Wno-incompatible-pointer-types" } */
+
+struct B { int i; };
+struct C { struct B b; } __attribute__ ((packed));
+
+long* g8 (struct C *p) { return p; }
+/* { dg-warning "increases the alignment of '.*' pointer from 1 to " "" {
target *-*-* } .-1 } */
diff --git a/gcc/testsuite/gcc.target/i386/avx512bw-vmovdqu16-2.c
b/gcc/testsuite/gcc.target/i386/avx512bw-vmovdqu16-2.c
index a61609c40d2..c6e3ebdc507 100644
--- a/gcc/testsuite/gcc.target/i386/avx512bw-vmovdqu16-2.c
+++ b/gcc/testsuite/gcc.target/i386/avx512bw-vmovdqu16-2.c
@@ -1,5 +1,5 @@
/* { dg-do run } */
-/* { dg-options "-O2 -mavx512bw" } */
+/* { dg-options "-O2 -mavx512bw -Wno-address-of-packed-member" } */
/* { dg-require-effective-target avx512bw } */
#define AVX512BW
diff --git a/gcc/testsuite/gcc.target/i386/avx512f-vmovdqu32-2.c
b/gcc/testsuite/gcc.target/i386/avx512f-vmovdqu32-2.c
index f2edc3dff7b..95a657fc5ff 100644
--- a/gcc/testsuite/gcc.target/i386/avx512f-vmovdqu32-2.c
+++ b/gcc/testsuite/gcc.target/i386/avx512f-vmovdqu32-2.c
@@ -1,5 +1,5 @@
/* { dg-do run } */
-/* { dg-options "-O2 -mavx512f" } */
+/* { dg-options "-O2 -mavx512f -Wno-address-of-packed-member" } */
/* { dg-require-effective-target avx512f } */
#define AVX512F
diff --git a/gcc/testsuite/gcc.target/i386/avx512f-vmovdqu64-2.c
b/gcc/testsuite/gcc.target/i386/avx512f-vmovdqu64-2.c
index 14176965ace..954b091d976 100644
--- a/gcc/testsuite/gcc.target/i386/avx512f-vmovdqu64-2.c
+++ b/gcc/testsuite/gcc.target/i386/avx512f-vmovdqu64-2.c
@@ -1,5 +1,5 @@
/* { dg-do run } */
-/* { dg-options "-O2 -mavx512f" } */
+/* { dg-options "-O2 -mavx512f -Wno-address-of-packed-member" } */
/* { dg-require-effective-target avx512f } */
#define AVX512F
diff --git a/gcc/testsuite/gcc.target/i386/avx512vl-vmovdqu16-2.c
b/gcc/testsuite/gcc.target/i386/avx512vl-vmovdqu16-2.c
index 45ae83d4552..81465f8d9a0 100644
--- a/gcc/testsuite/gcc.target/i386/avx512vl-vmovdqu16-2.c
+++ b/gcc/testsuite/gcc.target/i386/avx512vl-vmovdqu16-2.c
@@ -1,5 +1,5 @@
/* { dg-do run } */
-/* { dg-options "-O2 -mavx512bw -mavx512vl" } */
+/* { dg-options "-O2 -mavx512bw -mavx512vl -Wno-address-of-packed-member" } */
/* { dg-require-effective-target avx512vl } */
/* { dg-require-effective-target avx512bw } */
diff --git a/gcc/testsuite/gcc.target/i386/avx512vl-vmovdqu32-2.c
b/gcc/testsuite/gcc.target/i386/avx512vl-vmovdqu32-2.c
index 4b928d0cd42..19390664bd0 100644
--- a/gcc/testsuite/gcc.target/i386/avx512vl-vmovdqu32-2.c
+++ b/gcc/testsuite/gcc.target/i386/avx512vl-vmovdqu32-2.c
@@ -1,5 +1,5 @@
/* { dg-do run } */
-/* { dg-options "-O2 -mavx512vl" } */
+/* { dg-options "-O2 -mavx512vl -Wno-address-of-packed-member" } */
/* { dg-require-effective-target avx512vl } */
#define AVX512VL
diff --git a/gcc/testsuite/gcc.target/i386/avx512vl-vmovdqu64-2.c
b/gcc/testsuite/gcc.target/i386/avx512vl-vmovdqu64-2.c
index 1863ed3616f..aea0c12a5ff 100644
--- a/gcc/testsuite/gcc.target/i386/avx512vl-vmovdqu64-2.c
+++ b/gcc/testsuite/gcc.target/i386/avx512vl-vmovdqu64-2.c
@@ -1,5 +1,5 @@
/* { dg-do run } */
-/* { dg-options "-O2 -mavx512vl" } */
+/* { dg-options "-O2 -mavx512vl -Wno-address-of-packed-member" } */
/* { dg-require-effective-target avx512vl } */
#define AVX512VL
diff --git a/libgcc/unwind-pe.h b/libgcc/unwind-pe.h
index dd5ae95fc2c..05c2fb4dd50 100644
--- a/libgcc/unwind-pe.h
+++ b/libgcc/unwind-pe.h
@@ -177,6 +177,9 @@ read_sleb128 (const unsigned char *p, _sleb128_t *val)
The function returns P incremented past the value. BASE is as given
by base_of_encoded_value for this encoding in the appropriate context. */
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Waddress-of-packed-member"
+
static const unsigned char *
read_encoded_value_with_base (unsigned char encoding, _Unwind_Ptr base,
const unsigned char *p, _Unwind_Ptr *val)
@@ -270,6 +273,8 @@ read_encoded_value_with_base (unsigned char encoding,
_Unwind_Ptr base,
return p;
}
+#pragma GCC diagnostic pop
+
#ifndef NO_BASE_OF_ENCODED_VALUE
/* Like read_encoded_value_with_base, but get the base from the context
--
2.17.0
