c++/reflection: check TYPE_BEING_DEFINED in define_aggregateHEADtrunkmaster

As discussed in
<https://gcc.gnu.org/pipermail/gcc-patches/2026-January/705756.html>,
we should check TYPE_BEING_DEFINED along with COMPLETE_TYPE_P in
eval_define_aggregate.  It seems that with this check added, we don't
need this code anymore:

      if (c == type)
        {
          auto_diagnostic_group d;
          error_at (loc, "%<define_aggregate%> evaluated from "
                         "%<consteval%> block enclosed by %qT being "
                         "defined", type);
	  //...
	}

so I'm removing that in this patch.

gcc/cp/ChangeLog:

	* reflect.cc (eval_define_aggregate): Also give an error when
	TYPE_BEING_DEFINED is true for the first argument.  Remove code
	that did the same.

gcc/testsuite/ChangeLog:

	* g++.dg/reflect/define_aggregate3.C: Adjust expected diagnostic.
	* g++.dg/reflect/p2996-21.C: Likewise.

Reviewed-by: Jakub Jelinek <jakub@redhat.com>
Reviewed-by: Jason Merrill <jason@redhat.com>

2 files changed, 10 insertions, 10 deletions

diff --git a/gcc/testsuite/g++.dg/reflect/define_aggregate3.C b/gcc/testsuite/g++.dg/reflect/define_aggregate3.C
index db04a80..5951f7c 100644
--- a/gcc/testsuite/g++.dg/reflect/define_aggregate3.C
+++ b/gcc/testsuite/g++.dg/reflect/define_aggregate3.C
@@ -15,8 +15,8 @@ consteval bool foo () { return define_aggregate (^^S2, {}) == ^^S2; }
 const bool a = foo ();					// { dg-error "call to consteval function 'foo\\\(\\\)' is not a constant expression" }
 
 struct S3 {
-  consteval {						// { dg-message "'consteval' block defined here" }
-    define_aggregate (^^S3, {});			// { dg-error "'define_aggregate' evaluated from 'consteval' block enclosed by 'S3' being defined" }
+  consteval {
+    define_aggregate (^^S3, {});			// { dg-error "first 'define_aggregate' argument is a reflection of a class type .S3. being defined" }
   }
 };
 
@@ -33,26 +33,26 @@ consteval {
 
 template <typename T>
 struct S5 {
-  consteval {						// { dg-message "'consteval' block defined here" }
-    define_aggregate (^^S5 <T>, {});			// { dg-error "'define_aggregate' evaluated from 'consteval' block enclosed by 'S5<int>' being defined" }
+  consteval {
+    define_aggregate (^^S5 <T>, {});			// { dg-error "first 'define_aggregate' argument is a reflection of a class type .S5<int>. being defined" }
   }
 };
 
 S5 <int> s5;
 
-consteval bool bar (info x) { return define_aggregate (x, {}) == x; }	// { dg-error "'define_aggregate' evaluated from 'consteval' block enclosed by 'S6' being defined" }
+consteval bool bar (info x) { return define_aggregate (x, {}) == x; }	// { dg-error "first 'define_aggregate' argument is a reflection of a class type .S6. being defined" }
 
 struct S6 {
-  consteval {						// { dg-message "'consteval' block defined here" }
+  consteval {
     bar (^^S6);
   }
 };
 
-consteval bool baz (info x) { return define_aggregate (x, {}) == x; }	// { dg-error "'define_aggregate' evaluated from 'consteval' block enclosed by 'S7<char>' being defined" }
+consteval bool baz (info x) { return define_aggregate (x, {}) == x; }	// { dg-error "first 'define_aggregate' argument is a reflection of a class type .S7<char>. being defined" }
 
 template <typename T>
 struct S7 {
-  consteval {						// { dg-message "'consteval' block defined here" }
+  consteval {
     baz (^^S7 <T>);
   }
 };
diff --git a/gcc/testsuite/g++.dg/reflect/p2996-21.C b/gcc/testsuite/g++.dg/reflect/p2996-21.C
index 8a9f789..478be47 100644
--- a/gcc/testsuite/g++.dg/reflect/p2996-21.C
+++ b/gcc/testsuite/g++.dg/reflect/p2996-21.C
@@ -7,9 +7,9 @@
 using namespace std::meta;
 
 struct S0 {
-  consteval {						// { dg-message "'consteval' block defined here" }
+  consteval {
     std::meta::define_aggregate(^^S0, {});		// error: scope associated with S0 encloses the consteval block
-  }							// { dg-error "'define_aggregate' evaluated from 'consteval' block enclosed by 'S0' being defined" "" { target *-*-* } .-1 }
+  }							// { dg-error "first 'define_aggregate' argument is a reflection of a class type .S0. being defined" "" { target *-*-* } .-1 }
 };
 
 struct S1;