circogen: CMake: define NEATOGEN_EXPORTS

circogen is part of the neato_layout plugin.

Fixes errors like this using CMake with MinGW:

circogen.lib(circularinit.obj) : error LNK2019: unresolved external symbol __imp_spline_edges referenced in function circo_layout [C:\Users\magja\graphviz\build\plugin\neato_layout\gvplugin_neato_layout.vcxproj]

Towards https://gitlab.com/graphviz/graphviz/-/issues/2058

diff --git a/lib/circogen/CMakeLists.txt b/lib/circogen/CMakeLists.txt
index eebbe5b68e841d32a3ab306186fa4573be6dd708..7aa09faaf794ec86880748d853fd7831be622c1e 100644 (file)
--- a/lib/circogen/CMakeLists.txt
+++ b/lib/circogen/CMakeLists.txt
@@ -1,3 +1,5 @@
+add_definitions(-DNEATOGEN_EXPORTS=1)
+
 add_library(circogen STATIC
     # Header files
     block.h