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re PR c++/47897 ([C++0x] static const member variable is not constant expression)

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PR c++/47897
	* semantics.c (non_const_var_error): Split out from...
	(cxx_eval_constant_expression): ...here.
	(potential_constant_expression_1) [VAR_DECL]: Use it.
	Allow dependent variables.

From-SVN: r170532
This commit is contained in:
Jason Merrill 2011-02-27 03:13:16 -05:00 • committed by Jason Merrill
parent fe8e67ef97
commit acfd3fffee
8 changed files with 82 additions and 45 deletions
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8
gcc/cp/ChangeLog
View file

@ -1,3 +1,11 @@
2011-02-26 Jason Merrill <jason@redhat.com>
PR c++/47897
* semantics.c (non_const_var_error): Split out from...
(cxx_eval_constant_expression): ...here.
(potential_constant_expression_1) [VAR_DECL]: Use it.
Allow dependent variables.
2011-02-24 Jason Merrill <jason@redhat.com>
* parser.c (cp_parser_constant_expression): Set

79
gcc/cp/semantics.c
View file

@ -6704,6 +6704,46 @@ cxx_eval_indirect_ref (const constexpr_call *call, tree t,
return r;
}
/* Complain about R, a VAR_DECL, not being usable in a constant expression.
Shared between potential_constant_expression and
cxx_eval_constant_expression. */
static void
non_const_var_error (tree r)
{
tree type = TREE_TYPE (r);
error ("the value of %qD is not usable in a constant "
"expression", r);
if (DECL_DECLARED_CONSTEXPR_P (r))
inform (DECL_SOURCE_LOCATION (r),
"%qD used in its own initializer", r);
else if (INTEGRAL_OR_ENUMERATION_TYPE_P (type))
{
if (!CP_TYPE_CONST_P (type))
inform (DECL_SOURCE_LOCATION (r),
"%q#D is not const", r);
else if (CP_TYPE_VOLATILE_P (type))
inform (DECL_SOURCE_LOCATION (r),
"%q#D is volatile", r);
else if (!DECL_INITIAL (r))
inform (DECL_SOURCE_LOCATION (r),
"%qD was not initialized with a constant "
"expression", r);
else
gcc_unreachable ();
}
else
{
if (cxx_dialect >= cxx0x && !DECL_DECLARED_CONSTEXPR_P (r))
inform (DECL_SOURCE_LOCATION (r),
"%qD was not declared %<constexpr%>", r);
else
inform (DECL_SOURCE_LOCATION (r),
"%qD does not have integral or enumeration type",
r);
}
}
/* Attempt to reduce the expression T to a constant value.
On failure, issue diagnostic and return error_mark_node. */
/* FIXME unify with c_fully_fold */
@ -6744,39 +6784,7 @@ cxx_eval_constant_expression (const constexpr_call *call, tree t,
if (DECL_P (r))
{
if (!allow_non_constant)
{
tree type = TREE_TYPE (r);
error ("the value of %qD is not usable in a constant "
"expression", r);
if (DECL_DECLARED_CONSTEXPR_P (r))
inform (DECL_SOURCE_LOCATION (r),
"%qD used in its own initializer", r);
else if (INTEGRAL_OR_ENUMERATION_TYPE_P (type))
{
if (!CP_TYPE_CONST_P (type))
inform (DECL_SOURCE_LOCATION (r),
"%q#D is not const", r);
else if (CP_TYPE_VOLATILE_P (type))
inform (DECL_SOURCE_LOCATION (r),
"%q#D is volatile", r);
else if (!DECL_INITIAL (r))
inform (DECL_SOURCE_LOCATION (r),
"%qD was not initialized with a constant "
"expression", r);
else
gcc_unreachable ();
}
else
{
if (cxx_dialect >= cxx0x && !DECL_DECLARED_CONSTEXPR_P (r))
inform (DECL_SOURCE_LOCATION (r),
"%qD was not declared %<constexpr%>", r);
else
inform (DECL_SOURCE_LOCATION (r),
"%qD does not have integral or enumeration type",
r);
}
}
non_const_var_error (r);
*non_constant_p = true;
}
break;
@ -7371,10 +7379,11 @@ potential_constant_expression_1 (tree t, bool want_rval, tsubst_flags_t flags)
return potential_constant_expression_1 (TREE_OPERAND (t, 0), rval, flags);
case VAR_DECL:
if (want_rval && !decl_constant_var_p (t))
if (want_rval && !decl_constant_var_p (t)
&& !dependent_type_p (TREE_TYPE (t)))
{
if (flags & tf_error)
error ("variable %qD is not declared constexpr", t);
non_const_var_error (t);
return false;
}
return true;

8
gcc/testsuite/ChangeLog
View file

@ -1,3 +1,11 @@
2011-02-26 Jason Merrill <jason@redhat.com>
* g++.dg/cpp0x/regress/template-const1.C: New.
* g++.dg/cpp0x/regress/template-function1.C: Adjust.
* g++.dg/template/function1.C: Adjust.
* g++.dg/cpp0x/regress/debug-debug7.C: Adjust.
* g++.dg/debug/debug7.C: Adjust.
2011-02-26 Tobias Burnus <burnus@net-b.de>
PR fortran/47886

4
gcc/testsuite/g++.dg/cpp0x/regress/debug-debug7.C
View file

@ -7,8 +7,8 @@ int
main() {
int a = 4;
int b = 5;
int (*x)[b] = new int[a][b]; // { dg-error "" }
int b = 5; // { dg-message "not const" }
int (*x)[b] = new int[a][b]; // { dg-error "not usable" }
x[2][1] = 7;

9
gcc/testsuite/g++.dg/cpp0x/regress/template-const1.C Normal file
View file

@ -0,0 +1,9 @@
// PR c++/47897
// { dg-options -std=c++0x }
template < typename T, T N >
struct S
{
static const T value = N;
typedef S< T, value + 1 > next;
};

9
gcc/testsuite/g++.dg/cpp0x/regress/template-function1.C
View file

@ -1,28 +1,29 @@
// PR c++/38647
// { dg-do compile }
// { dg-options "-std=c++0x" }
// { dg-prune-output "note" }
template<const char *, int> struct A {};
const char func[] = "abc";
template<int N> struct A<func, N> {}; // { dg-error "cannot appear|is invalid|not a valid|not declared constexpr" }
template<int N> struct A<func, N> {}; // { dg-error "cannot appear|is invalid|not a valid|constant expression" }
char a1[1];
A<a1, 0> a;
template<const char *, int> struct B {};
template<int N> struct B<__FUNCTION__, N> {}; // { dg-error "cannot appear|is invalid|is not a valid|not declared constexpr" }
template<int N> struct B<__FUNCTION__, N> {}; // { dg-error "cannot appear|is invalid|is not a valid|constant expression" }
char b1[1];
B<b1, 0> b;
template<const char *, int> struct C {};
template<int N> struct C<__PRETTY_FUNCTION__, N> {}; // { dg-error "cannot appear|is invalid|is not a valid|not declared constexpr" }
template<int N> struct C<__PRETTY_FUNCTION__, N> {}; // { dg-error "cannot appear|is invalid|is not a valid|constant expression" }
char c1[1];
C<c1, 0> c;
template<const char *, int> struct D {};
template<int N> struct D<__func__, N> {}; // { dg-error "cannot appear|is invalid|is not a valid|function scope|not declared constexpr" }
template<int N> struct D<__func__, N> {}; // { dg-error "cannot appear|is invalid|is not a valid|function scope|constant expression" }
char d1[1];
D<d1, 0> d;

1
gcc/testsuite/g++.dg/debug/debug7.C
View file

@ -1,4 +1,5 @@
// { dg-do compile }
// { dg-prune-output "note" }
void f (int);

9
gcc/testsuite/g++.dg/template/function1.C
View file

@ -1,27 +1,28 @@
// PR c++/38647
// { dg-do compile }
// { dg-prune-output "note" }
template<const char *, int> struct A {};
const char func[] = "abc";
template<int N> struct A<func, N> {}; // { dg-error "cannot appear|is invalid|not a valid|not declared constexpr" }
template<int N> struct A<func, N> {}; // { dg-error "cannot appear|is invalid|not a valid|constant expression" }
char a1[1];
A<a1, 0> a;
template<const char *, int> struct B {};
template<int N> struct B<__FUNCTION__, N> {}; // { dg-error "cannot appear|is invalid|is not a valid|not declared constexpr" }
template<int N> struct B<__FUNCTION__, N> {}; // { dg-error "cannot appear|is invalid|is not a valid|constant expression" }
char b1[1];
B<b1, 0> b;
template<const char *, int> struct C {};
template<int N> struct C<__PRETTY_FUNCTION__, N> {}; // { dg-error "cannot appear|is invalid|is not a valid|not declared constexpr" }
template<int N> struct C<__PRETTY_FUNCTION__, N> {}; // { dg-error "cannot appear|is invalid|is not a valid|constant expression" }
char c1[1];
C<c1, 0> c;
template<const char *, int> struct D {};
template<int N> struct D<__func__, N> {}; // { dg-error "cannot appear|is invalid|is not a valid|function scope|not declared constexpr" }
template<int N> struct D<__func__, N> {}; // { dg-error "cannot appear|is invalid|is not a valid|function scope|constant expression" }
char d1[1];
D<d1, 0> d;