Use installed pybind11 and other CMake fixes (#2009)

* Use installed pybind11 and other CMake fixes

- Adds OTIO_FIND_PYBIND11 configuration option to tell CMake
to look for a pre-installed pybind11 instead of using the
vendored copy. Follows existing pattern for Imath and rapidjson dependencies.
[Issue #2006](#2006).

- A couple of bugfixes in src/deps/CMakeLists.txt
  - checking for empty submodule directories was broken
  - rapidjson subdmodule would not get built

- Generated CMake files get installed in
/usr/local/lib/cmake/opentime and opentimelineio
instead of /usr/local/share/opentime and opentimelineio which
is what the CMake documentation suggests.
[Issue #2008](#2008).

Signed-off-by: Jean-Francois Panisset <panisset@gmail.com>

* Don't try to build rapidjson

rapidjson as a submodule won't build in our environment due
to old CMake version requirements, and since it's a header-only
library, we only need the headers to be present to allow
opentimelineio to build.

Signed-off-by: Jean-Francois Panisset <panisset@gmail.com>

---------

Signed-off-by: Jean-Francois Panisset <panisset@gmail.com>

Author: jfpanisset

CMakeLists.txt

@@ -38,6 +38,7 @@ option(OTIO_DEPENDENCIES_INSTALL      "Install OTIO's C++ header dependencies (I
 option(OTIO_INSTALL_PYTHON_MODULES    "Install OTIO pure Python modules/files" ON)
 option(OTIO_INSTALL_COMMANDLINE_TOOLS "Install the OTIO command line tools" ON)
 option(OTIO_FIND_IMATH                "Find Imath using find_package" OFF)
+option(OTIO_FIND_PYBIND11             "Find pybind11 using find_package" OFF)
 option(OTIO_FIND_RAPIDJSON            "Find RapidJSON using find_package" OFF)
 set(OTIO_PYTHON_INSTALL_DIR "" CACHE STRING "Python installation dir (such as the site-packages dir)")
 
@@ -258,6 +259,16 @@ else()
     include_directories("${PROJECT_SOURCE_DIR}/src/deps/Imath/src")
 endif()
 
+#----- pybind11
+if(OTIO_FIND_PYBIND11)
+    find_package(pybind11 REQUIRED)
+    if (pybind11_FOUND)
+        message(STATUS "Found pybind11 at ${pybind11_CONFIG}")
+    endif()
+else()
+    message(STATUS "Using src/deps/pybind11 by default")
+endif()
+
 #----- RapidJSON
 
 if(OTIO_FIND_RAPIDJSON)

src/deps/CMakeLists.txt

@@ -4,14 +4,21 @@
 #----- Other dependencies
 
 # detect if the submodules haven't been updated
-set(DEPS_SUBMODULES pybind11)
+if(NOT OTIO_FIND_PYBIND11 AND OTIO_PYTHON_INSTALL)
+    # pybind11 only needed when building Python bindings
+    set(DEPS_SUBMODULES ${DEPS_SUBMODULES} pybind11)
+endif()
+
+if(NOT OTIO_FIND_IMATH)
+    set(DEPS_SUBMODULES ${DEPS_SUBMODULES} Imath)
+endif()
 
 if(NOT OTIO_FIND_RAPIDJSON)
     set(DEPS_SUBMODULES ${DEPS_SUBMODULES} rapidjson)
 endif()
 
 foreach(submodule IN LISTS DEPS_SUBMODULES)
-    file(GLOB SUBMOD_CONTENTS ${submodule})
+    file(GLOB SUBMOD_CONTENTS "${submodule}/*")
     list(LENGTH SUBMOD_CONTENTS SUBMOD_CONTENT_LEN)
     if(SUBMOD_CONTENT_LEN EQUAL 0)
         message(
@@ -21,10 +28,25 @@ foreach(submodule IN LISTS DEPS_SUBMODULES)
     endif()
 endforeach()
 
-if(OTIO_PYTHON_INSTALL)
+if(NOT OTIO_FIND_PYBIND11 AND OTIO_PYTHON_INSTALL)
+    # pybind11 only needed when building Python bindings
     add_subdirectory(pybind11)
 endif()
 
+# Calling add_subdirectory(rapidjson) will try to build subcomponents
+# such as example/CMakeLists.txt which has not been updated for CMake
+# 4.0 compatibility and will break our builds. rapidjson is a header
+# only library, code in src/opentimelineio/ only needs it to be present
+# to pick up the headers.
+# If building rapidjson ends up required, the CMake variables:
+#
+# RAPIDJSON_BUILD_DOC
+# RAPIDJSON_BUILD_EXAMPLES
+# RAPIDJSON_BUILD_TESTS
+#
+# coud be overriden from ON to OFF to avoid trying to build
+# subcomponents we don't need.
+
 if(NOT OTIO_FIND_IMATH)
     # preserve BUILD_SHARED_LIBS options for this project, but set it off for Imath
     option(BUILD_SHARED_LIBS "Build shared libraries" ON)

src/opentime/CMakeLists.txt

@@ -64,15 +64,15 @@ if(OTIO_CXX_INSTALL)
             RUNTIME DESTINATION "${OTIO_RESOLVED_CXX_DYLIB_INSTALL_DIR}")
 
     install(EXPORT OpenTimeTargets
-            DESTINATION "${OTIO_RESOLVED_CXX_INSTALL_DIR}/share/opentime"
+            DESTINATION "${OTIO_RESOLVED_CXX_INSTALL_DIR}/lib/cmake/opentime"
             NAMESPACE OTIO:: )
 
     include(CMakePackageConfigHelpers)
     configure_package_config_file(
         ${CMAKE_CURRENT_SOURCE_DIR}/OpenTimeConfig.cmake.in
         ${CMAKE_CURRENT_BINARY_DIR}/OpenTimeConfig.cmake
         INSTALL_DESTINATION
-            ${OTIO_RESOLVED_CXX_INSTALL_DIR}/share/opentime
+            ${OTIO_RESOLVED_CXX_INSTALL_DIR}/lib/cmake/opentime
         NO_SET_AND_CHECK_MACRO
         NO_CHECK_REQUIRED_COMPONENTS_MACRO
     )
@@ -87,7 +87,7 @@ if(OTIO_CXX_INSTALL)
             ${CMAKE_CURRENT_BINARY_DIR}/OpenTimeConfig.cmake
             ${CMAKE_CURRENT_BINARY_DIR}/OpenTimeConfigVersion.cmake
         DESTINATION
-            ${OTIO_RESOLVED_CXX_INSTALL_DIR}/share/opentime
+            ${OTIO_RESOLVED_CXX_INSTALL_DIR}/lib/cmake/opentime
     )
 endif()
 

src/opentimelineio/CMakeLists.txt

@@ -142,15 +142,15 @@ if(OTIO_CXX_INSTALL)
            RUNTIME DESTINATION "${OTIO_RESOLVED_CXX_DYLIB_INSTALL_DIR}")
 
     install(EXPORT OpenTimelineIOTargets
-           DESTINATION "${OTIO_RESOLVED_CXX_INSTALL_DIR}/share/opentimelineio"
+           DESTINATION "${OTIO_RESOLVED_CXX_INSTALL_DIR}/lib/cmake/opentimelineio"
            NAMESPACE OTIO:: )
 
     include(CMakePackageConfigHelpers)
     configure_package_config_file(
         ${CMAKE_CURRENT_SOURCE_DIR}/OpenTimelineIOConfig.cmake.in
         ${CMAKE_CURRENT_BINARY_DIR}/OpenTimelineIOConfig.cmake
         INSTALL_DESTINATION
-            ${OTIO_RESOLVED_CXX_INSTALL_DIR}/share/opentimelineio
+            ${OTIO_RESOLVED_CXX_INSTALL_DIR}/lib/cmake/opentimelineio
         NO_SET_AND_CHECK_MACRO
         NO_CHECK_REQUIRED_COMPONENTS_MACRO
     )
@@ -165,6 +165,6 @@ if(OTIO_CXX_INSTALL)
             ${CMAKE_CURRENT_BINARY_DIR}/OpenTimelineIOConfig.cmake
             ${CMAKE_CURRENT_BINARY_DIR}/OpenTimelineIOConfigVersion.cmake
         DESTINATION
-            ${OTIO_RESOLVED_CXX_INSTALL_DIR}/share/opentimelineio
+            ${OTIO_RESOLVED_CXX_INSTALL_DIR}/lib/cmake/opentimelineio
     )
 endif()