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Update the C FE routine "add_flexible_array_elts_to_size" C++ FE routine "layout_var_decl" to handle the cases when the DECL is union.

Browse source 
PR c/53548

Add testing cases to test the _bos for flexible array members in unions
or alone in structures.

gcc/c/ChangeLog:

	PR c/53548
	* c-decl.cc (add_flexible_array_elts_to_size): Handle the cases
	when the DECL is union.

gcc/cp/ChangeLog:

	PR c/53548
	* decl.cc (layout_var_decl): Handle the cases when the DECL is
	union with a flexible array member initializer.

gcc/testsuite/ChangeLog:

	PR c/53548
	* c-c++-common/fam-in-union-alone-in-struct-bos-1.c: New test.
	* c-c++-common/fam-in-union-alone-in-struct-bos.c: New test.
This commit is contained in:
Qing Zhao 2024-05-06 16:28:01 +00:00
parent 93f6a47583
commit 6634a40912
4 changed files with 159 additions and 13 deletions
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29
gcc/c/c-decl.cc
View file

@ -5339,8 +5339,9 @@ zero_length_array_type_p (const_tree type)
}
/* INIT is a constructor that forms DECL's initializer. If the final
element initializes a flexible array field, add the size of that
initializer to DECL's size. */
element initializes a flexible array field, adjust the size of the
DECL with the initializer based on whether the DECL is a union or
a structure. */
static void
add_flexible_array_elts_to_size (tree decl, tree init)
@ -5355,10 +5356,26 @@ add_flexible_array_elts_to_size (tree decl, tree init)
if (flexible_array_member_type_p (type))
{
complete_array_type (&type, elt, false);
DECL_SIZE (decl)
= size_binop (PLUS_EXPR, DECL_SIZE (decl), TYPE_SIZE (type));
DECL_SIZE_UNIT (decl)
= size_binop (PLUS_EXPR, DECL_SIZE_UNIT (decl), TYPE_SIZE_UNIT (type));
/* For a structure, add the size of the initializer to the DECL's
size. */
if (TREE_CODE (TREE_TYPE (decl)) == RECORD_TYPE)
{
DECL_SIZE (decl)
= size_binop (PLUS_EXPR, DECL_SIZE (decl), TYPE_SIZE (type));
DECL_SIZE_UNIT (decl)
= size_binop (PLUS_EXPR, DECL_SIZE_UNIT (decl),
TYPE_SIZE_UNIT (type));
}
/* For a union, the DECL's size is the maximum of the current size
and the size of the initializer. */
else
{
DECL_SIZE (decl)
= size_binop (MAX_EXPR, DECL_SIZE (decl), TYPE_SIZE (type));
DECL_SIZE_UNIT (decl)
= size_binop (MAX_EXPR, DECL_SIZE_UNIT (decl),
TYPE_SIZE_UNIT (type));
}
}
}

32
gcc/cp/decl.cc
View file

@ -6563,8 +6563,9 @@ layout_var_decl (tree decl)
}
}
/* If the final element initializes a flexible array field, add the size of
that initializer to DECL's size. */
/* If the final element initializes a flexible array field, adjust
the size of the DECL with the initializer based on whether the
DECL is a union or a structure. */
if (type != error_mark_node
&& DECL_INITIAL (decl)
&& TREE_CODE (DECL_INITIAL (decl)) == CONSTRUCTOR
@ -6585,11 +6586,28 @@ layout_var_decl (tree decl)
&& TREE_CODE (vtype) == ARRAY_TYPE
&& COMPLETE_TYPE_P (vtype))
{
DECL_SIZE (decl)
= size_binop (PLUS_EXPR, DECL_SIZE (decl), TYPE_SIZE (vtype));
DECL_SIZE_UNIT (decl)
= size_binop (PLUS_EXPR, DECL_SIZE_UNIT (decl),
TYPE_SIZE_UNIT (vtype));
/* For a structure, add the size of the initializer to the DECL's
size. */
if (TREE_CODE (TREE_TYPE (decl)) == RECORD_TYPE)
{
DECL_SIZE (decl)
= size_binop (PLUS_EXPR, DECL_SIZE (decl),
TYPE_SIZE (vtype));
DECL_SIZE_UNIT (decl)
= size_binop (PLUS_EXPR, DECL_SIZE_UNIT (decl),
TYPE_SIZE_UNIT (vtype));
}
/* For a union, the DECL's size is the maximum of the current size
and the size of the initializer. */
else
{
DECL_SIZE (decl)
= size_binop (MAX_EXPR, DECL_SIZE (decl),
TYPE_SIZE (vtype));
DECL_SIZE_UNIT (decl)
= size_binop (MAX_EXPR, DECL_SIZE_UNIT (decl),
TYPE_SIZE_UNIT (vtype));
}
}
}
}

66
gcc/testsuite/c-c++-common/fam-in-union-alone-in-struct-bos-1.c Normal file
View file

@ -0,0 +1,66 @@
/* testing flexible array members in unions and alone in structures:
__bos/__bdos */
/* { dg-do run } */
/* { dg-options "-O2" } */
union with_fam_1 {
char a;
int b[];
} *with_fam_1_v;
union with_fam_2 {
int a;
char b[];
} *with_fam_2_v;
union with_fam_3 {
char a[];
int b[];
} *with_fam_3_v;
struct only_fam {
int b[];
} *only_fam_v;
struct only_fam_2 {
unsigned int : 2;
unsigned int : 3;
int b[];
} *only_fam_2_v;
void __attribute__((__noinline__))
setup (int n1, int n2, int n3, int n4, int n5)
{
with_fam_1_v = (union with_fam_1 *) __builtin_malloc (n1 * sizeof (int));
with_fam_2_v = (union with_fam_2 *) __builtin_malloc (n2 * sizeof (char));
with_fam_3_v = (union with_fam_3 *) __builtin_malloc (n3 * sizeof (int));
only_fam_v = (struct only_fam *) __builtin_malloc (n4 * sizeof (int));
only_fam_2_v = (struct only_fam_2 *) __builtin_malloc (n5 * sizeof (int));
return;
}
void __attribute__((__noinline__)) stuff(
union with_fam_1 *with_fam_1_v,
union with_fam_2 *with_fam_2_v,
union with_fam_3 *with_fam_3_v,
struct only_fam *only_fam_v,
struct only_fam_2 *only_fam_2_v)
{
if (__builtin_object_size(with_fam_1_v->b, 1) != -1)
__builtin_abort ();
if (__builtin_object_size(with_fam_2_v->b, 1) != -1)
__builtin_abort ();
if (__builtin_object_size(with_fam_3_v->b, 1) != -1)
__builtin_abort ();
if (__builtin_object_size(only_fam_v->b, 1) != -1)
__builtin_abort ();
if (__builtin_object_size(only_fam_2_v->b, 1) != -1)
__builtin_abort ();
}
int main (int argc, char *argv[])
{
setup (2, 3, 4, 5, 6);
stuff (with_fam_1_v, with_fam_2_v, with_fam_3_v, only_fam_v, only_fam_2_v);
return 0;
}

45
gcc/testsuite/c-c++-common/fam-in-union-alone-in-struct-bos.c Normal file
View file

@ -0,0 +1,45 @@
/* testing flexible array members in unions and alone in structures:
__bos/__bdos */
/* { dg-do run } */
/* { dg-options "-O2" } */
union with_fam_1 {
char a;
int b[];
} with_fam_1_v = {.b = {1, 2, 3, 4, 5}};
union with_fam_2 {
int a;
char b[];
} with_fam_2_v = {.a = 0x1f2f3f4f};
union with_fam_3 {
char a[];
int b[];
} with_fam_3_v = {.b = {0x1f2f3f4f, 0x5f6f7f7f}};
struct only_fam {
int b[];
} only_fam_v = {{7, 11}};
struct only_fam_2 {
unsigned int : 2;
unsigned int : 3;
int b[];
} only_fam_2_v = {{7, 11}};
int main ()
{
if (__builtin_object_size(with_fam_1_v.b, 1) != 20)
__builtin_abort ();
if (__builtin_object_size(with_fam_2_v.b, 1) != 4)
__builtin_abort ();
if (__builtin_object_size(with_fam_3_v.b, 1) != 8)
__builtin_abort ();
if (__builtin_object_size(only_fam_v.b, 1) != 8)
__builtin_abort ();
if (__builtin_object_size(only_fam_2_v.b, 1) != 8)
__builtin_abort ();
return 0;
}