Hi!
The following patch implements my understanding of P1937R2, though I wonder
if https://eel.is/c++draft/expr.const#14.example-1 shouldn't have been
also either removed or adjusted by the P1937R2 paper.
Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
2020-02-24 Jakub Jelinek <ja...@redhat.com>
P1937R2 - Fixing inconsistencies between const{expr,eval} functions
* call.c (build_over_call): Don't evaluate immediate functions in
unevaluated operands.
* g++.dg/ext/consteval1.C: Change dg-{message,error} into dg-bogus.
* g++.dg/cpp2a/consteval6.C: Likewise.
* g++.dg/cpp2a/consteval3.C: Change dg-error for unevaluated operands
into dg-bogus.
--- gcc/cp/call.c.jj 2020-02-08 10:58:28.439866081 +0100
+++ gcc/cp/call.c 2020-02-15 22:18:20.311789273 +0100
@@ -8424,6 +8424,7 @@ build_over_call (struct z_candidate *can
current_function_returns_abnormally = 1;
if (TREE_CODE (fn) == FUNCTION_DECL
&& DECL_IMMEDIATE_FUNCTION_P (fn)
+ && cp_unevaluated_operand == 0
&& (current_function_decl == NULL_TREE
|| !DECL_IMMEDIATE_FUNCTION_P (current_function_decl))
&& (current_binding_level->kind != sk_function_parms
@@ -9060,6 +9061,7 @@ build_over_call (struct z_candidate *can
tree fndecl = STRIP_TEMPLATE (TREE_OPERAND (fn, 0));
if (TREE_CODE (fndecl) == FUNCTION_DECL
&& DECL_IMMEDIATE_FUNCTION_P (fndecl)
+ && cp_unevaluated_operand == 0
&& (current_function_decl == NULL_TREE
|| !DECL_IMMEDIATE_FUNCTION_P (current_function_decl))
&& (current_binding_level->kind != sk_function_parms
--- gcc/testsuite/g++.dg/ext/consteval1.C.jj 2020-01-12 11:54:37.166402048
+0100
+++ gcc/testsuite/g++.dg/ext/consteval1.C 2020-02-15 22:33:12.690505111
+0100
@@ -2,5 +2,5 @@
// { dg-options "-std=c++2a" }
consteval int foo (int x) { return x; }
-int d = 6; // { dg-message "'int d' is not const" }
-bool e = __builtin_has_attribute (foo (d), packed); // { dg-error "the
value of 'd' is not usable in a constant expression" }
+int d = 6; // { dg-bogus "'int d' is not const" }
+bool e = __builtin_has_attribute (foo (d), packed); // { dg-bogus "the
value of 'd' is not usable in a constant expression" }
--- gcc/testsuite/g++.dg/cpp2a/consteval3.C.jj 2020-01-12 11:54:37.140402440
+0100
+++ gcc/testsuite/g++.dg/cpp2a/consteval3.C 2020-02-15 22:22:50.618765423
+0100
@@ -33,9 +33,9 @@ struct V { consteval int v = 5; }; // {
struct W { consteval static int w; }; // { dg-error "static data member 'w'
declared 'consteval'" }
int i = sizeof (&f6); // { dg-error "taking address of an
immediate function 'consteval int f6\\(int\\)'" }
using j = decltype (&f6); // { dg-error "taking address of an
immediate function 'consteval int f6\\(int\\)'" }
-int k = sizeof (f6 (d)); // { dg-error "the value of 'd' is not
usable in a constant expression" }
-using l = decltype (f6 (d)); // { dg-error "the value of 'd' is not
usable in a constant expression" }
-bool m = noexcept (f6 (d)); // { dg-error "the value of 'd' is not
usable in a constant expression" }
+int k = sizeof (f6 (d)); // { dg-bogus "the value of 'd' is not
usable in a constant expression" }
+using l = decltype (f6 (d)); // { dg-bogus "the value of 'd' is not
usable in a constant expression" }
+bool m = noexcept (f6 (d)); // { dg-bogus "the value of 'd' is not
usable in a constant expression" }
namespace std {
using size_t = decltype (sizeof (0));
}
--- gcc/testsuite/g++.dg/cpp2a/consteval6.C.jj 2020-01-12 11:54:37.140402440
+0100
+++ gcc/testsuite/g++.dg/cpp2a/consteval6.C 2020-02-15 22:32:11.140421368
+0100
@@ -3,7 +3,7 @@
struct A {
constexpr A () {}
- A (A const&) = delete; // { dg-message "declared here" }
+ A (A const&) = delete; // { dg-bogus "declared here" }
};
template<typename T>
@@ -19,8 +19,8 @@ consteval void
bar ()
{
T t;
- T u = t; // { dg-error "use of deleted function" }
+ T u = t; // { dg-bogus "use of deleted function" }
}
using B = decltype (foo<A> ());
-using C = decltype (bar<A> ()); // { dg-message "required from here" }
+using C = decltype (bar<A> ()); // { dg-bogus "required from here" }
Jakub
