Take care of QT_REDUCE_RELOCATIONS-related error for ODB compiler

2 files changed, 22 insertions, 0 deletions

diff --git a/odb/qt/details/config.hxx b/odb/qt/details/config.hxx
index 0e968a2..d4c2bab 100644
--- a/odb/qt/details/config.hxx
+++ b/odb/qt/details/config.hxx
@@ -9,6 +9,23 @@
 
 #ifdef _MSC_VER
 #elif defined(ODB_COMPILER)
+// Qt5 may complain if we are building without -fPIC or -fPIE. Instead of
+// asking the user to pass one of these options to the ODB compiler (which
+// can, BTW, be done with -x -fPIE, for example, if one is not using the
+// Qt profile), we are going to define __PIE__ ourselves just to silence
+// Qt. We also want to try to minimize this to cases where it is actually
+// necessary. To achieve this, we need to include the Qt config file without
+// including <QtGlobals>, which is where the test for PIC/PIE is. While
+// newer versions of Qt (from 4.7) have <QtConfig>, to support older
+// versions we will include qconfig.h directly. This file appears to be
+// present in all the versions starting with Qt 4.0.
+//
+#  if defined(__ELF__) && !defined(__PIC__) && !defined(__PIE__)
+#    include <QtCore/qconfig.h> // QT_REDUCE_RELOCATIONS
+#    ifdef QT_REDUCE_RELOCATIONS
+#      define __PIE__
+#    endif
+#  endif
 #  define LIBODB_QT_STATIC_LIB
 #else
 #  include <odb/qt/details/config.h>
diff --git a/odb/qt/version.options b/odb/qt/version.options
index 262f339..43c3d39 100644
--- a/odb/qt/version.options
+++ b/odb/qt/version.options
@@ -2,6 +2,11 @@
 # copyright : Copyright (c) 2009-2012 Code Synthesis Tools CC
 # license   : GNU GPL v2; see accompanying LICENSE file
 
+# Include the config file first so that it can do its thing before we
+# include any Qt headers.
+#
+--odb-prologue '#include <odb/qt/details/config.hxx>'
+
 # Make sure the options files as seen by the ODB compiler and header
 # files as seen by the C++ compiler have the same Qt interface version.
 #