Use METIS system library if so selected

.github/scripts/unix.sh

@@ -68,6 +68,8 @@ function configure()
       -DGTSAM_USE_QUATERNIONS=${GTSAM_USE_QUATERNIONS:-OFF} \
       -DGTSAM_ROT3_EXPMAP=${GTSAM_ROT3_EXPMAP:-ON} \
       -DGTSAM_POSE3_EXPMAP=${GTSAM_POSE3_EXPMAP:-ON} \
+      -DGTSAM_USE_SYSTEM_EIGEN=${GTSAM_USE_SYSTEM_EIGEN:-OFF} \
+      -DGTSAM_USE_SYSTEM_METIS=${GTSAM_USE_SYSTEM_METIS:-OFF} \
       -DGTSAM_BUILD_WITH_MARCH_NATIVE=OFF \
       -DBOOST_ROOT=$BOOST_ROOT \
       -DBoost_NO_SYSTEM_PATHS=ON \

.github/workflows/build-special.yml

@@ -55,6 +55,12 @@ jobs:
             version: "9"
             flag: cayley
 
+          - name: ubuntu-system-libs
+            os: ubuntu-18.04
+            compiler: gcc
+            version: "9"
+            flag: system-libs
+
     steps:
       - name: Checkout
         uses: actions/checkout@v2
@@ -126,6 +132,12 @@ jobs:
           echo "GTSAM_ROT3_EXPMAP=OFF" >> $GITHUB_ENV
           echo "GTSAM Uses Cayley map for Rot3"
 
+      - name: Use system versions of 3rd party libraries
+        if: matrix.flag == 'system'
+        run: |
+          echo "GTSAM_USE_SYSTEM_EIGEN=ON" >> $GITHUB_ENV
+          echo "GTSAM_USE_SYSTEM_METIS=ON" >> $GITHUB_ENV
+
       - name: Build & Test
         run: |
           bash .github/scripts/unix.sh -t

CMakeLists.txt

@@ -38,11 +38,14 @@ if(${GTSAM_SOURCE_DIR} STREQUAL ${GTSAM_BINARY_DIR})
   message(FATAL_ERROR "In-source builds not allowed. Please make a new directory (called a build directory) and run CMake from there. You may need to remove CMakeCache.txt. ")
 endif()
 
+include(cmake/HandleGeneralOptions.cmake)   # CMake build options
+
+# Libraries:
 include(cmake/HandleBoost.cmake)            # Boost
 include(cmake/HandleCCache.cmake)           # ccache
 include(cmake/HandleCPack.cmake)            # CPack
 include(cmake/HandleEigen.cmake)            # Eigen3
-include(cmake/HandleGeneralOptions.cmake)  # CMake build options
+include(cmake/HandleMetis.cmake)            # metis
 include(cmake/HandleMKL.cmake)              # MKL
 include(cmake/HandleOpenMP.cmake)           # OpenMP
 include(cmake/HandlePerfTools.cmake)        # Google perftools

cmake/HandleMetis.cmake

@@ -0,0 +1,44 @@
+###############################################################################
+# Metis library
+
+# For both system or bundle version, a cmake target "metis-gtsam-if" is defined (interface library)
+
+# Dont try to use metis if GTSAM_SUPPORT_NESTED_DISSECTION is disabled:
+if (NOT GTSAM_SUPPORT_NESTED_DISSECTION)
+  return()
+endif()
+
+option(GTSAM_USE_SYSTEM_METIS "Find and use system-installed libmetis. If 'off', use the one bundled with GTSAM" OFF)
+
+if(GTSAM_USE_SYSTEM_METIS)
+  # 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(metis-gtsam-if INTERFACE)
+    target_include_directories(metis-gtsam-if BEFORE INTERFACE ${METIS_INCLUDE_DIR})
+    target_link_libraries(metis-gtsam-if INTERFACE ${METIS_LIBRARY})
+  endif()
+else()
+  # Bundled version:
+  option(GTSAM_BUILD_METIS_EXECUTABLES "Build metis library executables" OFF)
+  add_subdirectory(${GTSAM_SOURCE_DIR}/gtsam/3rdparty/metis)
+
+  target_include_directories(metis-gtsam BEFORE PUBLIC
+    $<BUILD_INTERFACE:${GTSAM_SOURCE_DIR}/gtsam/3rdparty/metis/include>
+    $<BUILD_INTERFACE:${GTSAM_SOURCE_DIR}/gtsam/3rdparty/metis/libmetis>
+    $<BUILD_INTERFACE:${GTSAM_SOURCE_DIR}/gtsam/3rdparty/metis/GKlib>
+    $<INSTALL_INTERFACE:include/gtsam/3rdparty/metis/>
+  )
+
+  add_library(metis-gtsam-if INTERFACE)
+  target_link_libraries(metis-gtsam-if INTERFACE metis-gtsam)
+endif()
+
+list(APPEND GTSAM_EXPORTED_TARGETS metis-gtsam-if)
+install(TARGETS metis-gtsam-if EXPORT GTSAM-exports ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR})

cmake/HandlePrintConfiguration.cmake

@@ -32,6 +32,7 @@ endif()
 print_build_options_for_target(gtsam)
 
 print_config("Use System Eigen" "${GTSAM_USE_SYSTEM_EIGEN} (Using version: ${GTSAM_EIGEN_VERSION})")
+print_config("Use System Metis" "${GTSAM_USE_SYSTEM_METIS}")
 
 if(GTSAM_USE_TBB)
     print_config("Use Intel TBB" "Yes (Version: ${TBB_VERSION})")

gtsam/3rdparty/CMakeLists.txt

@@ -49,10 +49,7 @@ if(NOT GTSAM_USE_SYSTEM_EIGEN)
 
 endif()
 
-option(GTSAM_BUILD_METIS_EXECUTABLES "Build metis library executables" OFF)
-if(GTSAM_SUPPORT_NESTED_DISSECTION)
-	add_subdirectory(metis)
-endif()
+# metis: already handled in ROOT/cmake/HandleMetis.cmake
 
 add_subdirectory(ceres)
 

gtsam/CMakeLists.txt

@@ -88,7 +88,8 @@ list(APPEND gtsam_srcs "${PROJECT_BINARY_DIR}/config.h" "${PROJECT_BINARY_DIR}/d
 install(FILES "${PROJECT_BINARY_DIR}/config.h" "${PROJECT_BINARY_DIR}/dllexport.h" DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}/gtsam)
 
 if(GTSAM_SUPPORT_NESTED_DISSECTION)
-    list(APPEND GTSAM_ADDITIONAL_LIBRARIES metis-gtsam)
+    # target metis-gtsam-if is defined in both cases: embedded metis or system version:
+    list(APPEND GTSAM_ADDITIONAL_LIBRARIES metis-gtsam-if)
 endif()
 
 # Versions
@@ -154,16 +155,6 @@ target_include_directories(gtsam SYSTEM BEFORE PUBLIC
   $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/3rdparty/CCOLAMD/Include>
   $<INSTALL_INTERFACE:include/gtsam/3rdparty/CCOLAMD>
 )
-if(GTSAM_SUPPORT_NESTED_DISSECTION)
-  target_include_directories(gtsam BEFORE PUBLIC
-    $<BUILD_INTERFACE:${GTSAM_SOURCE_DIR}/gtsam/3rdparty/metis/include>
-    $<BUILD_INTERFACE:${GTSAM_SOURCE_DIR}/gtsam/3rdparty/metis/libmetis>
-    $<BUILD_INTERFACE:${GTSAM_SOURCE_DIR}/gtsam/3rdparty/metis/GKlib>
-    $<INSTALL_INTERFACE:include/gtsam/3rdparty/metis/>
-  )
-endif()
-
-
 
 if(WIN32) # Add 'lib' prefix to static library to avoid filename collision with shared library
 	if (NOT BUILD_SHARED_LIBS)

gtsam/config.h.in

@@ -77,3 +77,6 @@
 
 // Support Metis-based nested dissection
 #cmakedefine GTSAM_TANGENT_PREINTEGRATION
+
+// Whether to use the system installed Metis instead of the provided one
+#cmakedefine GTSAM_USE_SYSTEM_METIS

gtsam/inference/Ordering.cpp

@@ -25,8 +25,12 @@
 #include <gtsam/3rdparty/CCOLAMD/Include/ccolamd.h>
 
 #ifdef GTSAM_SUPPORT_NESTED_DISSECTION
+#ifdef GTSAM_USE_SYSTEM_METIS
+#include <metis.h>
+#else
 #include <gtsam/3rdparty/metis/include/metis.h>
 #endif
+#endif
 
 using namespace std;
 

gtsam_unstable/partition/FindSeparator-inl.h

@@ -20,6 +20,8 @@
 
 #include "FindSeparator.h"
 
+#ifndef GTSAM_USE_SYSTEM_METIS
+
 extern "C" {
 #include <metis.h>
 #include "metislib.h"
@@ -564,3 +566,5 @@ namespace gtsam { namespace partition {
   }
 
 }} //namespace
+
+#endif

gtsam_unstable/partition/tests/testFindSeparator.cpp

@@ -20,6 +20,8 @@ using namespace std;
 using namespace gtsam;
 using namespace gtsam::partition;
 
+#ifndef GTSAM_USE_SYSTEM_METIS
+
 /* ************************************************************************* */
 // x0 - x1 - x2
 // l3        l4
@@ -227,6 +229,8 @@ TEST ( Partition, findSeparator3_with_reduced_camera )
   LONGS_EQUAL(2, partitionTable[28]);
 }
 
+#endif
+
 /* ************************************************************************* */
 int main() { TestResult tr; return TestRegistry::runAllTests(tr);}
 /* ************************************************************************* */