From 5481159f95296193b1accd525bcafaa0617c03ce Mon Sep 17 00:00:00 2001
From: Varun Agrawal <varagrawal@gmail.com>
Date: Thu, 28 Dec 2023 09:31:08 -0500
Subject: [PATCH] Link to cephes from gtsam

---
 CMakeLists.txt           |  1 +
 cmake/HandleCephes.cmake | 47 ++++++++++++++++++++++++++++++++++++++++
 gtsam/CMakeLists.txt     |  3 +++
 3 files changed, 51 insertions(+)
 create mode 100644 cmake/HandleCephes.cmake

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 16848a721..8e0497f8d 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -72,6 +72,7 @@ include(cmake/HandleCCache.cmake)           # ccache
 include(cmake/HandleCPack.cmake)            # CPack
 include(cmake/HandleEigen.cmake)            # Eigen3
 include(cmake/HandleMetis.cmake)            # metis
+include(cmake/HandleCephes.cmake)            # cephes
 include(cmake/HandleMKL.cmake)              # MKL
 include(cmake/HandleOpenMP.cmake)           # OpenMP
 include(cmake/HandlePerfTools.cmake)        # Google perftools
diff --git a/cmake/HandleCephes.cmake b/cmake/HandleCephes.cmake
new file mode 100644
index 000000000..6ef406987
--- /dev/null
+++ b/cmake/HandleCephes.cmake
@@ -0,0 +1,47 @@
+# ##############################################################################
+# Cephes library
+
+# For both system or bundle version, a cmake target "cephes-gtsam-if" is defined
+# (interface library)
+
+option(
+  GTSAM_USE_SYSTEM_CEPHES
+  "Find and use system-installed cephes. If 'off', use the one bundled with GTSAM"
+  OFF)
+
+if(GTSAM_USE_SYSTEM_CEPHES)
+  # # Debian package: libmetis-dev
+
+  # find_path(METIS_INCLUDE_DIR metis.h REQUIRED) find_library(METIS_LIBRARY
+  # metis REQUIRED)
+
+  # if(METIS_INCLUDE_DIR AND METIS_LIBRARY) mark_as_advanced(METIS_INCLUDE_DIR)
+  # mark_as_advanced(METIS_LIBRARY)
+
+  # add_library(cephes-gtsam-if INTERFACE)
+  # target_include_directories(cephes-gtsam-if BEFORE INTERFACE
+  # ${METIS_INCLUDE_DIR} # gtsam_unstable/partition/FindSeparator-inl.h uses
+  # internal metislib.h API # via extern "C"
+  # $<BUILD_INTERFACE:${GTSAM_SOURCE_DIR}/gtsam/3rdparty/metis/libmetis>
+  # $<BUILD_INTERFACE:${GTSAM_SOURCE_DIR}/gtsam/3rdparty/metis/GKlib> )
+  # target_link_libraries(cephes-gtsam-if INTERFACE ${METIS_LIBRARY}) endif()
+
+else()
+  # Bundled version:
+  add_subdirectory(${GTSAM_SOURCE_DIR}/gtsam/3rdparty/cephes)
+
+  list(APPEND GTSAM_EXPORTED_TARGETS cephes-gtsam)
+  set(GTSAM_EXPORTED_TARGETS
+      "${GTSAM_EXPORTED_TARGETS}"
+      PARENT_SCOPE)
+
+  add_library(cephes-gtsam-if INTERFACE)
+  target_link_libraries(cephes-gtsam-if INTERFACE cephes-gtsam)
+
+endif()
+
+list(APPEND GTSAM_EXPORTED_TARGETS cephes-gtsam-if)
+install(
+  TARGETS cephes-gtsam-if
+  EXPORT GTSAM-exports
+  ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR})
diff --git a/gtsam/CMakeLists.txt b/gtsam/CMakeLists.txt
index e35f5aada..1fc8e4570 100644
--- a/gtsam/CMakeLists.txt
+++ b/gtsam/CMakeLists.txt
@@ -110,6 +110,9 @@ if(GTSAM_SUPPORT_NESTED_DISSECTION)
     list(APPEND GTSAM_ADDITIONAL_LIBRARIES metis-gtsam-if)
 endif()
 
+# Link to cephes library
+list(APPEND GTSAM_ADDITIONAL_LIBRARIES cephes-gtsam-if)
+
 # Versions
 set(gtsam_version   ${GTSAM_VERSION_STRING})
 set(gtsam_soversion ${GTSAM_VERSION_MAJOR})