From 990f40de0d5d00b0b344ac938219ee66664da5df Mon Sep 17 00:00:00 2001
From: Stefano Carrazza <stefano.carrazza@cern.ch>
Date: Fri, 24 Aug 2018 10:44:20 +0200
Subject: [PATCH] adding compiler option to enable/disable fortran wrapper,
 included example in fortran

---
 CMakeLists.txt          |  6 ++++++
 examples/fortran_test.f | 19 +++++++++++++++++++
 2 files changed, 25 insertions(+)
 create mode 100644 examples/fortran_test.f

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 214fba7..d3a477e 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -93,6 +93,12 @@ install(FILES ${PROJECT_SOURCE_DIR}/src/qcdloop.pc DESTINATION lib/pkgconfig)
 install(DIRECTORY src/qcdloop DESTINATION include)
 install(TARGETS qcdloop DESTINATION lib)
 
+# enable disable fortran/wrapper (to avoid name conflicts with ql1.x)
+option(ENABLE_FORTRAN_WRAPPER "Enable fortran wrapper" ON)
+if(ENABLE_FORTRAN_WRAPPER)
+  add_definitions(-DQL_NAMES)
+endif()
+
 # qcdloop examples
 option(ENABLE_EXAMPLES "Compile test examples" OFF)
 if(ENABLE_EXAMPLES)
diff --git a/examples/fortran_test.f b/examples/fortran_test.f
new file mode 100644
index 0000000..fb4d2a0
--- /dev/null
+++ b/examples/fortran_test.f
@@ -0,0 +1,19 @@
+!     Example of fortran code calling the c++ library
+!     compile with: gfortran fortran_test.f `qcdloop-config --ldflags`
+      
+      program main
+      implicit none
+      double complex qli1
+      double precision m, mu2
+
+!     init qcdloop objects
+      call qlinit()
+
+      m = 5d0
+      mu2 = 1.7d0**2     
+!     call some test function
+      write(*,*) qli1(m, mu2, 0)
+      write(*,*) qli1(m, mu2, 1)
+      write(*,*) qli1(m, mu2, 2)
+      
+      end