From c67f2b63a9769d8ae3a07f78afd0c7dd2873563a Mon Sep 17 00:00:00 2001
From: Boris Kolpackov <boris@codesynthesis.com>
Date: Fri, 23 Jan 2015 12:21:49 +0200
Subject: Diagnose lack of default constructor in pointed-to objects

Lack of the default constructor will lead to uncompilable generated code.
---
 odb/processor.cxx       | 22 +++++++++++++++++++++-
 odb/semantics/class.cxx |  8 +++++++-
 2 files changed, 28 insertions(+), 2 deletions(-)

diff --git a/odb/processor.cxx b/odb/processor.cxx
index 291dcd3..a6f18e0 100644
--- a/odb/processor.cxx
+++ b/odb/processor.cxx
@@ -1313,6 +1313,9 @@ namespace
         }
       }
 
+      bool poly (polymorphic (*c));
+      bool abst (abstract (*c));
+
       // Make sure the pointed-to class is complete.
       //
       if (!c->complete ())
@@ -1334,7 +1337,7 @@ namespace
 
       // Make sure the pointed-to class is not reuse-abstract.
       //
-      if (abstract (*c) && !polymorphic (*c))
+      if (abst && !poly)
       {
         os << m.file () << ":" << m.line () << ":" << m.column () << ": "
            << "error: pointed-to class '" << class_fq_name (*c) << "' "
@@ -1362,6 +1365,23 @@ namespace
         throw operation_failed ();
       }
 
+      // Make sure the pointed-to class has a default ctor. Since we will
+      // use database::load() in the generated code, lack of a default ctor
+      // will lead to uncompilable generated code. Poly-abstract is Ok.
+      //
+      if (!c->default_ctor () && !(abst && poly))
+      {
+        os << m.file () << ":" << m.line () << ":" << m.column () << ": "
+           << "error: pointed-to class '" << class_fq_name (*c) << "' "
+           << "has no default constructor" << endl;
+
+        os << c->file () << ":" << c->line () << ":" << c->column () << ": "
+           << "info: class '" << class_name (*c) << "' is defined here"
+           << endl;
+
+        throw operation_failed ();
+      }
+
       // See if this is the inverse side of a bidirectional relationship.
       // If so, then resolve the member and cache it in the context.
       //
diff --git a/odb/semantics/class.cxx b/odb/semantics/class.cxx
index 2d35a17..8c6877b 100644
--- a/odb/semantics/class.cxx
+++ b/odb/semantics/class.cxx
@@ -24,7 +24,13 @@ namespace semantics
   bool class_::
   default_ctor () const
   {
-    return TYPE_HAS_DEFAULT_CONSTRUCTOR (tree_node ());
+    tree t (tree_node ());
+
+    // TYPE_HAS_DEFAULT_CONSTRUCTOR() returns true if we have a
+    // deleted default ctor. locate_ctor(), on the other hand,
+    // returns NULL_TREE in this case.
+    //
+    return TYPE_HAS_DEFAULT_CONSTRUCTOR (t) && locate_ctor (t) != NULL_TREE;
   }
 
   bool class_::
-- 
cgit v1.1