git
/
gcc
mirror of git://gcc.gnu.org/git/gcc.git
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

Implement P0017R1, C++17 aggregates with bases. 

* class.c (build_base_field_1): Split out from...
	(build_base_field): ...here.  In C++17 mode, build a field for
	empty bases.
	* decl.c (xref_basetypes): In C++17 aggregates can have bases.
	(next_initializable_field): Allow base fields in C++17.
	* typeck2.c (process_init_constructor_record): Likewise.

From-SVN: r241187
This commit is contained in:
Jason Merrill 2016-10-14 17:54:39 -04:00 committed by Jason Merrill
parent efc5aa6bc7
commit ec2416b5ff
12 changed files with 192 additions and 32 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

10
gcc/cp/ChangeLog
View File

@ -1,3 +1,13 @@
2016-10-14 Jason Merrill <jason@redhat.com>
Implement P0017R1, C++17 aggregates with bases.
* class.c (build_base_field_1): Split out from...
(build_base_field): ...here. In C++17 mode, build a field for
empty bases.
* decl.c (xref_basetypes): In C++17 aggregates can have bases.
(next_initializable_field): Allow base fields in C++17.
* typeck2.c (process_init_constructor_record): Likewise.
2016-10-14 Jakub Jelinek <jakub@redhat.com>
DR 1511 - const volatile variables and ODR

73
gcc/cp/class.c
View File

@ -4452,6 +4452,34 @@ layout_empty_base (record_layout_info rli, tree binfo,
return atend;
}
/* Build the FIELD_DECL for BASETYPE as a base of T, add it to the chain of
fields at NEXT_FIELD, and return it. */
static tree
build_base_field_1 (tree t, tree basetype, tree *&next_field)
{
/* Create the FIELD_DECL. */
gcc_assert (CLASSTYPE_AS_BASE (basetype));
tree decl = build_decl (input_location,
FIELD_DECL, NULL_TREE, CLASSTYPE_AS_BASE (basetype));
DECL_ARTIFICIAL (decl) = 1;
DECL_IGNORED_P (decl) = 1;
DECL_FIELD_CONTEXT (decl) = t;
DECL_SIZE (decl) = CLASSTYPE_SIZE (basetype);
DECL_SIZE_UNIT (decl) = CLASSTYPE_SIZE_UNIT (basetype);
SET_DECL_ALIGN (decl, CLASSTYPE_ALIGN (basetype));
DECL_USER_ALIGN (decl) = CLASSTYPE_USER_ALIGN (basetype);
DECL_MODE (decl) = TYPE_MODE (basetype);
DECL_FIELD_IS_BASE (decl) = 1;
/* Add the new FIELD_DECL to the list of fields for T. */
DECL_CHAIN (decl) = *next_field;
*next_field = decl;
next_field = &DECL_CHAIN (decl);
return decl;
}
/* Layout the base given by BINFO in the class indicated by RLI.
*BASE_ALIGN is a running maximum of the alignments of
any base class. OFFSETS gives the location of empty base
@ -4483,29 +4511,12 @@ build_base_field (record_layout_info rli, tree binfo,
CLASSTYPE_EMPTY_P (t) = 0;
/* Create the FIELD_DECL. */
decl = build_decl (input_location,
FIELD_DECL, NULL_TREE, CLASSTYPE_AS_BASE (basetype));
DECL_ARTIFICIAL (decl) = 1;
DECL_IGNORED_P (decl) = 1;
DECL_FIELD_CONTEXT (decl) = t;
if (CLASSTYPE_AS_BASE (basetype))
{
DECL_SIZE (decl) = CLASSTYPE_SIZE (basetype);
DECL_SIZE_UNIT (decl) = CLASSTYPE_SIZE_UNIT (basetype);
SET_DECL_ALIGN (decl, CLASSTYPE_ALIGN (basetype));
DECL_USER_ALIGN (decl) = CLASSTYPE_USER_ALIGN (basetype);
DECL_MODE (decl) = TYPE_MODE (basetype);
DECL_FIELD_IS_BASE (decl) = 1;
decl = build_base_field_1 (t, basetype, next_field);
/* Try to place the field. It may take more than one try if we
have a hard time placing the field without putting two
objects of the same type at the same address. */
layout_nonempty_base_or_field (rli, decl, binfo, offsets);
/* Add the new FIELD_DECL to the list of fields for T. */
DECL_CHAIN (decl) = *next_field;
*next_field = decl;
next_field = &DECL_CHAIN (decl);
}
/* Try to place the field. It may take more than one try if we
have a hard time placing the field without putting two
objects of the same type at the same address. */
layout_nonempty_base_or_field (rli, decl, binfo, offsets);
}
else
{
@ -4536,11 +4547,17 @@ build_base_field (record_layout_info rli, tree binfo,
CLASSTYPE_NEARLY_EMPTY_P (t) = 0;
}
/* We do not create a FIELD_DECL for empty base classes because
it might overlap some other field. We want to be able to
create CONSTRUCTORs for the class by iterating over the
FIELD_DECLs, and the back end does not handle overlapping
FIELD_DECLs. */
/* We used to not create a FIELD_DECL for empty base classes because of
back end issues with overlapping FIELD_DECLs, but that doesn't seem to
be a problem anymore. We need them to handle initialization of C++17
aggregate bases. */
if (cxx_dialect >= cxx1z && !BINFO_VIRTUAL_P (binfo))
{
tree decl = build_base_field_1 (t, basetype, next_field);
DECL_FIELD_OFFSET (decl) = BINFO_OFFSET (binfo);
DECL_FIELD_BIT_OFFSET (decl) = bitsize_zero_node;
SET_DECL_OFFSET_ALIGN (decl, BITS_PER_UNIT);
}
/* An empty virtual base causes a class to be non-empty
-- but in that case we do not need to clear CLASSTYPE_EMPTY_P
@ -6586,7 +6603,7 @@ layout_class_type (tree t, tree *virtuals_p)
/* Make sure that empty classes are reflected in RLI at this
point. */
include_empty_classes(rli);
include_empty_classes (rli);
/* Make sure not to create any structures with zero size. */
if (integer_zerop (rli_size_unit_so_far (rli)) && CLASSTYPE_EMPTY_P (t))

14
gcc/cp/decl.c
View File

@ -5569,7 +5569,8 @@ next_initializable_field (tree field)
while (field
&& (TREE_CODE (field) != FIELD_DECL
|| (DECL_C_BIT_FIELD (field) && !DECL_NAME (field))
|| DECL_ARTIFICIAL (field)))
|| (DECL_ARTIFICIAL (field)
&& !(cxx_dialect >= cxx1z && DECL_FIELD_IS_BASE (field)))))
field = DECL_CHAIN (field);
return field;
@ -13153,8 +13154,8 @@ xref_basetypes (tree ref, tree base_list)
if (max_bases)
{
vec_alloc (BINFO_BASE_ACCESSES (binfo), max_bases);
/* An aggregate cannot have baseclasses. */
CLASSTYPE_NON_AGGREGATE (ref) = 1;
/* A C++98 POD cannot have base classes. */
CLASSTYPE_NON_LAYOUT_POD_P (ref) = true;
if (TREE_CODE (ref) == UNION_TYPE)
error ("derived union %qT invalid", ref);
@ -13182,6 +13183,13 @@ xref_basetypes (tree ref, tree base_list)
if (access == access_default_node)
access = default_access;
/* Before C++17, an aggregate cannot have base classes. In C++17, an
aggregate can't have virtual, private, or protected base classes. */
if (cxx_dialect < cxx1z
|| access != access_public_node
|| via_virtual)
CLASSTYPE_NON_AGGREGATE (ref) = true;
if (PACK_EXPANSION_P (basetype))
basetype = PACK_EXPANSION_PATTERN (basetype);
if (TREE_CODE (basetype) == TYPE_DECL)

5
gcc/cp/typeck2.c
View File

@ -1352,6 +1352,7 @@ process_init_constructor_record (tree type, tree init,
gcc_assert (TREE_CODE (type) == RECORD_TYPE);
gcc_assert (!CLASSTYPE_VBASECLASSES (type));
gcc_assert (!TYPE_BINFO (type)
|| cxx_dialect >= cxx1z
|| !BINFO_N_BASE_BINFOS (TYPE_BINFO (type)));
gcc_assert (!TYPE_POLYMORPHIC_P (type));
@ -1369,7 +1370,9 @@ process_init_constructor_record (tree type, tree init,
if (!DECL_NAME (field) && DECL_C_BIT_FIELD (field))
continue;
if (TREE_CODE (field) != FIELD_DECL || DECL_ARTIFICIAL (field))
if (TREE_CODE (field) != FIELD_DECL
|| (DECL_ARTIFICIAL (field)
&& !(cxx_dialect >= cxx1z && DECL_FIELD_IS_BASE (field))))
continue;
/* If this is a bitfield, first convert to the declared type. */

23
gcc/testsuite/g++.dg/cpp1z/aggr-base1.C Normal file
View File

@ -0,0 +1,23 @@
// { dg-options -std=c++1z }
// { dg-do run }
struct base1 { int b1, b2 = 42; };
struct base2 {
base2() {
b3 = 42;
}
int b3;
};
struct derived : base1, base2 {
int d;
};
derived d1{{1, 2}, {}, 4};
derived d2{{}, {}, 4};
#define assert(X) do { if (!(X)) __builtin_abort(); } while(0)
int main()
{
assert (d1.b1 == 1 && d1.b2 == 2 && d1.b3 == 42 && d1.d == 4);
assert (d2.b1 == 0 && d2.b2 == 42 && d2.b3 == 42 && d2.d == 4);
}

15
gcc/testsuite/g++.dg/cpp1z/aggr-base1a.C Normal file
View File

@ -0,0 +1,15 @@
// { dg-do compile { target { c++11 && c++14_down } } }
struct base1 { int b1, b2 = 42; };
struct base2 {
base2() {
b3 = 42;
}
int b3;
};
struct derived : base1, base2 {
int d;
};
derived d1{{1, 2}, {}, 4}; // { dg-error "" }
derived d2{{}, {}, 4}; // { dg-error "" }

12
gcc/testsuite/g++.dg/cpp1z/aggr-base2.C Normal file
View File

@ -0,0 +1,12 @@
// { dg-options -std=c++1z }
struct derived;
struct base {
friend struct derived;
private:
base();
};
struct derived : base {};
derived d1{}; // { dg-error "" "" { target c++1z } }
derived d2; // still OK

12
gcc/testsuite/g++.dg/cpp1z/aggr-base2a.C Normal file
View File

@ -0,0 +1,12 @@
// { dg-do compile { target c++11 } }
struct derived;
struct base {
friend struct derived;
private:
base();
};
struct derived : base {};
derived d1{}; // { dg-error "" "" { target c++1z } }
derived d2; // still OK

11
gcc/testsuite/g++.dg/cpp1z/aggr-base3.C Normal file
View File

@ -0,0 +1,11 @@
// { dg-options -std=c++1z }
struct derived;
struct base { };
struct derived : base {
int i;
};
derived d1{1}; // { dg-error "base" }
derived d2{{},1}; // OK

21
gcc/testsuite/g++.dg/cpp1z/aggr-base4.C Normal file
View File

@ -0,0 +1,21 @@
// { dg-options -std=c++1z }
// { dg-do run }
struct derived;
struct base { };
struct derived : base {
int i;
};
bool flag;
base f() {
flag = true;
return base();
}
derived d2{f(),1};
int main()
{
return (!flag || d2.i != 1);
}

14
gcc/testsuite/g++.dg/cpp1z/aggr-base5.C Normal file
View File

@ -0,0 +1,14 @@
// { dg-options "-std=c++1z -w" }
// { dg-do run }
struct A { };
struct B: A { int i; };
struct C: A, B { int j; };
constexpr C c = { {}, { {}, 1 }, 2 };
#define assert(X) do { if (!(X)) __builtin_abort(); } while(0)
int main()
{
assert (c.i == 1 && c.j == 2);
}

14
gcc/testsuite/g++.dg/cpp1z/aggr-base6.C Normal file
View File

@ -0,0 +1,14 @@
// { dg-options "-std=c++1z -w" }
// { dg-do run }
struct A { };
struct B: A { int i; };
struct C: B, A { int j; };
constexpr C c = { { {}, 1 }, {}, 2 };
#define assert(X) do { if (!(X)) __builtin_abort(); } while(0)
int main()
{
assert (c.i == 1 && c.j == 2);
}