1 files changed, 31 insertions, 12 deletions

diff --git a/gcc/cp/constexpr.cc b/gcc/cp/constexpr.cc
index 4346b29..f56c5c4 100644
--- a/gcc/cp/constexpr.cc
+++ b/gcc/cp/constexpr.cc
@@ -307,7 +307,14 @@ is_valid_constexpr_fn (tree fun, bool complain)
     {
       ret = false;
       if (complain)
-	error ("%q#T has virtual base classes", DECL_CONTEXT (fun));
+	{
+	  if (DECL_CONSTRUCTOR_P (fun))
+	    error ("%<constexpr%> constructor in %q#T that has "
+		   "virtual base classes", DECL_CONTEXT (fun));
+	  else
+	    error ("%<constexpr%> destructor in %q#T that has "
+		   "virtual base classes", DECL_CONTEXT (fun));
+	}
     }
 
   return ret;
@@ -1048,6 +1055,12 @@ explain_invalid_constexpr_fn (tree fun)
 {
   static hash_set<tree> *diagnosed;
   tree body;
+
+  /* Don't try to explain a function we already complained about.  */
+  if (function *f = DECL_STRUCT_FUNCTION (fun))
+    if (f->language->erroneous)
+      return;
+
   /* In C++23, a function marked 'constexpr' may not actually be a constant
      expression.  We haven't diagnosed the problem yet: -Winvalid-constexpr
      wasn't enabled.  The function was called, so diagnose why it cannot be
@@ -3079,6 +3092,7 @@ cxx_eval_call_expression (const constexpr_ctx *ctx, tree t,
     }
 
   constexpr_ctx new_ctx = *ctx;
+  ctx = &new_ctx;
   if (DECL_CONSTRUCTOR_P (fun) && !ctx->object
       && TREE_CODE (t) == AGGR_INIT_EXPR)
     {
@@ -3088,16 +3102,12 @@ cxx_eval_call_expression (const constexpr_ctx *ctx, tree t,
       tree ctor = new_ctx.ctor = build_constructor (DECL_CONTEXT (fun), NULL);
       CONSTRUCTOR_NO_CLEARING (ctor) = true;
       ctx->global->put_value (new_ctx.object, ctor);
-      ctx = &new_ctx;
     }
   /* An immediate invocation is manifestly constant evaluated including the
      arguments of the call, so use mce_true even for the argument
      evaluation.  */
   if (DECL_IMMEDIATE_FUNCTION_P (fun))
-    {
-      new_ctx.manifestly_const_eval = mce_true;
-      ctx = &new_ctx;
-    }
+    new_ctx.manifestly_const_eval = mce_true;
 
   /* We used to shortcut trivial constructor/op= here, but nowadays
      we can only get a trivial function here with -fno-elide-constructors.  */
@@ -3185,6 +3195,11 @@ cxx_eval_call_expression (const constexpr_ctx *ctx, tree t,
         }
     }
 
+  /* Don't complain about problems evaluating an ill-formed function.  */
+  if (function *f = DECL_STRUCT_FUNCTION (fun))
+    if (f->language->erroneous)
+      new_ctx.quiet = true;
+
   int depth_ok = push_cx_call_context (t);
 
   /* Remember the object we are constructing or destructing.  */
@@ -9254,9 +9269,11 @@ cxx_eval_outermost_constant_expr (tree t, bool allow_non_constant,
       if (heap_var)
 	{
 	  if (!allow_non_constant && !non_constant_p)
-	    error_at (DECL_SOURCE_LOCATION (heap_var),
-		      "%qE is not a constant expression because it refers to "
-		      "a result of %<operator new%>", t);
+	    {
+	      error ("%qE is not a constant expression because it refers to "
+		     "a result of %<operator new%>", t);
+	      inform (DECL_SOURCE_LOCATION (heap_var), "allocated here");
+	    }
 	  r = t;
 	  non_constant_p = true;
 	}
@@ -9265,9 +9282,11 @@ cxx_eval_outermost_constant_expr (tree t, bool allow_non_constant,
 	  if (DECL_NAME (heap_var) != heap_deleted_identifier)
 	    {
 	      if (!allow_non_constant && !non_constant_p)
-		error_at (DECL_SOURCE_LOCATION (heap_var),
-			  "%qE is not a constant expression because allocated "
-			  "storage has not been deallocated", t);
+		{
+		  error ("%qE is not a constant expression because allocated "
+			 "storage has not been deallocated", t);
+		  inform (DECL_SOURCE_LOCATION (heap_var), "allocated here");
+		}
 	      r = t;
 	      non_constant_p = true;
 	    }