path: root/c0c10fd34df85706e5897fd79eea3fb40461f1c0.patch

From c0c10fd34df85706e5897fd79eea3fb40461f1c0 Mon Sep 17 00:00:00 2001
From: Korcan Hussein <korcan.hussein@collabora.com>
Date: Mon, 22 Sep 2025 11:56:59 +0100
Subject: [PATCH] cmake: fix eigen cmake packages for v5.0 (3.5)

Eigen changed from 3.x versioning to semver (3.5 became 5.0) and
dropped FindEigen3.cmake module support (deprecated in prior versions)
for config discovery.

Switch from find_package version constraints to manual version checking
to maintain compatibility with both versioning schemes (>= 3.3 old or
>= 5.0 new).

See: https://gitlab.com/libeigen/eigen/-/merge_requests/485
Part-of: <https://gitlab.freedesktop.org/monado/monado/-/merge_requests/2583>
---
 .gitlab-ci.yml                                |   4 +-
 .gitlab-ci/config.yml                         |   4 +-
 CMakeLists.txt                                |  14 ++-
 build.gradle                                  |   4 +-
 cmake/FindEigen3.cmake                        | 108 ------------------
 src/xrt/auxiliary/math/CMakeLists.txt         |   3 +-
 src/xrt/auxiliary/tracking/CMakeLists.txt     |   1 -
 src/xrt/auxiliary/util/CMakeLists.txt         |   3 -
 src/xrt/drivers/CMakeLists.txt                |   3 +-
 src/xrt/targets/openxr_android/build.gradle   |  10 +-
 src/xrt/tracking/hand/mercury/CMakeLists.txt  |  13 +--
 .../hand/mercury/kine_lm/CMakeLists.txt       |   2 -
 tests/CMakeLists.txt                          |   3 -
 13 files changed, 27 insertions(+), 145 deletions(-)
 delete mode 100644 cmake/FindEigen3.cmake

diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 9bca59e1b2..b5bb3085b2 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -433,7 +433,7 @@ ndk:armeabi-v7a:
   script:
 
     - .gitlab-ci/prebuild.sh
-    - .gitlab-ci/ci-cmake-build.sh -DANDROID_ABI=armeabi-v7a -DANDROID_PLATFORM=26 -DCMAKE_TOOLCHAIN_FILE=/opt/android-ndk/build/cmake/android.toolchain.cmake -DEigen3_DIR=/usr/lib/cmake/eigen3/ -DEIGEN3_INCLUDE_DIR=/usr/include/eigen3
+    - .gitlab-ci/ci-cmake-build.sh -DANDROID_ABI=armeabi-v7a -DANDROID_PLATFORM=26 -DCMAKE_TOOLCHAIN_FILE=/opt/android-ndk/build/cmake/android.toolchain.cmake -DEigen3_DIR=/usr/share/eigen3/cmake/
 
 ndk:arm64-v8a:
   stage: build
@@ -443,7 +443,7 @@ ndk:arm64-v8a:
   script:
 
     - .gitlab-ci/prebuild.sh
-    - .gitlab-ci/ci-cmake-build.sh -DANDROID_ABI=arm64-v8a -DANDROID_PLATFORM=26 -DCMAKE_TOOLCHAIN_FILE=/opt/android-ndk/build/cmake/android.toolchain.cmake -DEigen3_DIR=/usr/lib/cmake/eigen3/ -DEIGEN3_INCLUDE_DIR=/usr/include/eigen3
+    - .gitlab-ci/ci-cmake-build.sh -DANDROID_ABI=arm64-v8a -DANDROID_PLATFORM=26 -DCMAKE_TOOLCHAIN_FILE=/opt/android-ndk/build/cmake/android.toolchain.cmake -DEigen3_DIR=/usr/share/eigen3/cmake/
 
 android:spotlessCheck:
   stage: build
diff --git a/.gitlab-ci/config.yml b/.gitlab-ci/config.yml
index b03389406a..68632c213f 100644
--- a/.gitlab-ci/config.yml
+++ b/.gitlab-ci/config.yml
@@ -60,8 +60,8 @@ fdo_ci_templates_sha: 185ede0e9b9b1924b92306ab8b882a6294e92613
 .android_cmake_defines: &android_cmake_defines
   ANDROID_PLATFORM: 26
   CMAKE_TOOLCHAIN_FILE: /opt/android-ndk/build/cmake/android.toolchain.cmake
-  Eigen3_DIR: /usr/lib/cmake/eigen3/
-  EIGEN3_INCLUDE_DIR: /usr/include/eigen3
+  Eigen3_DIR: /usr/share/eigen3/cmake/
+
 
 # Which build job do we use to build the documentation.
 documentation_build: "debian:cmake"
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 4d64bce6d4..0e69331881 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -83,9 +83,17 @@ else()
 	endif()
 endif()
 
-# Redundant mention of version is required because module defaults to looking for 2.91-compatible,
-# which the config file for a 3.x says it's not compatible with.
-find_package(Eigen3 3 REQUIRED)
+#
+# For backwards compatibility with both version schemes,
+# we find any Eigen3 package (in config mode) and check
+# the version manually rather than using find_package
+# version constraints.
+#
+find_package(Eigen3 REQUIRED NO_MODULE)
+if(Eigen3_VERSION VERSION_LESS "3.3")
+	message(FATAL_ERROR "Eigen3 version ${Eigen3_VERSION} is too old, need at least 3.3")
+endif()
+
 find_package(Vulkan MODULE)
 find_package(HIDAPI MODULE)
 find_package(bluetooth MODULE)
diff --git a/build.gradle b/build.gradle
index 611775f1a4..1ad4494a70 100644
--- a/build.gradle
+++ b/build.gradle
@@ -80,9 +80,9 @@ ext {
     sharedTargetSdk = 31
     sharedMinSdk = 26
 
-    // If you are building on Windows, you will need to explicitly set eigenIncludeDir in your
+    // If you are building on Windows, you will need to explicitly set eigenCMakeDir in your
     // local.properties file since the default value provided below only makes sense on *nix
-    eigenIncludeDir = project.findProperty('eigenIncludeDir') ?: '/usr/include/eigen3'
+    eigenCMakeDir = project.findProperty('eigenCMakeDir') ?: '/usr/share/eigen3/cmake'
 
     // If you're having trouble with a "can't find python" CMake error, you can specify the path to
     // Python 3 explicitly in local.properties with a property named "pythonBinary"
diff --git a/cmake/FindEigen3.cmake b/cmake/FindEigen3.cmake
deleted file mode 100644
index b46df1c1bd..0000000000
--- a/cmake/FindEigen3.cmake
+++ /dev/null
@@ -1,108 +0,0 @@
-# - Try to find Eigen3 lib
-#
-# This module supports requiring a minimum version, e.g. you can do
-#   find_package(Eigen3 3.1.2)
-# to require version 3.1.2 or newer of Eigen3.
-#
-# Once done this will define
-#
-#  EIGEN3_FOUND - system has eigen lib with correct version
-#  EIGEN3_INCLUDE_DIR - the eigen include directory
-#  EIGEN3_VERSION - eigen version
-#
-# and the following imported target:
-#
-#  Eigen3::Eigen - The header-only Eigen library
-#
-# This module reads hints about search locations from
-# the following environment variables:
-#
-# EIGEN3_ROOT
-# EIGEN3_ROOT_DIR
-
-# Copyright (c) 2006, 2007 Montel Laurent, <montel@kde.org>
-# Copyright (c) 2008, 2009 Gael Guennebaud, <g.gael@free.fr>
-# Copyright (c) 2009 Benoit Jacob <jacob.benoit.1@gmail.com>
-# Redistribution and use is allowed according to the terms of the 2-clause BSD license.
-# SPDX-License-Identifier: BSD-2-Clause
-
-if(NOT Eigen3_FIND_VERSION)
-  if(NOT Eigen3_FIND_VERSION_MAJOR)
-    set(Eigen3_FIND_VERSION_MAJOR 2)
-  endif()
-  if(NOT Eigen3_FIND_VERSION_MINOR)
-    set(Eigen3_FIND_VERSION_MINOR 91)
-  endif()
-  if(NOT Eigen3_FIND_VERSION_PATCH)
-    set(Eigen3_FIND_VERSION_PATCH 0)
-  endif()
-
-  set(Eigen3_FIND_VERSION "${Eigen3_FIND_VERSION_MAJOR}.${Eigen3_FIND_VERSION_MINOR}.${Eigen3_FIND_VERSION_PATCH}")
-endif()
-
-macro(_eigen3_check_version)
-  file(READ "${EIGEN3_INCLUDE_DIR}/Eigen/src/Core/util/Macros.h" _eigen3_version_header)
-
-  string(REGEX MATCH "define[ \t]+EIGEN_WORLD_VERSION[ \t]+([0-9]+)" _eigen3_world_version_match "${_eigen3_version_header}")
-  set(EIGEN3_WORLD_VERSION "${CMAKE_MATCH_1}")
-  string(REGEX MATCH "define[ \t]+EIGEN_MAJOR_VERSION[ \t]+([0-9]+)" _eigen3_major_version_match "${_eigen3_version_header}")
-  set(EIGEN3_MAJOR_VERSION "${CMAKE_MATCH_1}")
-  string(REGEX MATCH "define[ \t]+EIGEN_MINOR_VERSION[ \t]+([0-9]+)" _eigen3_minor_version_match "${_eigen3_version_header}")
-  set(EIGEN3_MINOR_VERSION "${CMAKE_MATCH_1}")
-
-  set(EIGEN3_VERSION ${EIGEN3_WORLD_VERSION}.${EIGEN3_MAJOR_VERSION}.${EIGEN3_MINOR_VERSION})
-  if(${EIGEN3_VERSION} VERSION_LESS ${Eigen3_FIND_VERSION})
-    set(EIGEN3_VERSION_OK FALSE)
-  else()
-    set(EIGEN3_VERSION_OK TRUE)
-  endif()
-
-  if(NOT EIGEN3_VERSION_OK)
-
-    message(STATUS "Eigen3 version ${EIGEN3_VERSION} found in ${EIGEN3_INCLUDE_DIR}, "
-                   "but at least version ${Eigen3_FIND_VERSION} is required")
-  endif()
-endmacro()
-
-if (EIGEN3_INCLUDE_DIR)
-
-  # in cache already
-  _eigen3_check_version()
-  set(EIGEN3_FOUND ${EIGEN3_VERSION_OK})
-  set(Eigen3_FOUND ${EIGEN3_VERSION_OK})
-
-else ()
-
-  # search first if an Eigen3Config.cmake is available in the system,
-  # if successful this would set EIGEN3_INCLUDE_DIR and the rest of
-  # the script will work as usual
-  find_package(Eigen3 ${Eigen3_FIND_VERSION} NO_MODULE QUIET)
-
-  if(NOT EIGEN3_INCLUDE_DIR)
-    find_path(EIGEN3_INCLUDE_DIR NAMES signature_of_eigen3_matrix_library
-        HINTS
-        ENV EIGEN3_ROOT
-        ENV EIGEN3_ROOT_DIR
-        PATHS
-        ${CMAKE_INSTALL_PREFIX}/include
-        ${KDE4_INCLUDE_DIR}
-        PATH_SUFFIXES eigen3 eigen
-      )
-  endif()
-
-  if(EIGEN3_INCLUDE_DIR)
-    _eigen3_check_version()
-  endif()
-
-  include(FindPackageHandleStandardArgs)
-  find_package_handle_standard_args(Eigen3 DEFAULT_MSG EIGEN3_INCLUDE_DIR EIGEN3_VERSION_OK)
-
-  mark_as_advanced(EIGEN3_INCLUDE_DIR)
-
-endif()
-
-if(EIGEN3_FOUND AND NOT TARGET Eigen3::Eigen)
-  add_library(Eigen3::Eigen INTERFACE IMPORTED)
-  set_target_properties(Eigen3::Eigen PROPERTIES
-    INTERFACE_INCLUDE_DIRECTORIES "${EIGEN3_INCLUDE_DIR}")
-endif()
diff --git a/src/xrt/auxiliary/math/CMakeLists.txt b/src/xrt/auxiliary/math/CMakeLists.txt
index af963fc90d..ac66cf689c 100644
--- a/src/xrt/auxiliary/math/CMakeLists.txt
+++ b/src/xrt/auxiliary/math/CMakeLists.txt
@@ -46,10 +46,9 @@ add_library(
 	)
 target_link_libraries(
 	aux_math
-	PUBLIC aux-includes aux_util
+	PUBLIC aux-includes aux_util Eigen3::Eigen
 	PRIVATE xrt-optimized-math
 	)
-target_include_directories(aux_math SYSTEM PRIVATE ${EIGEN3_INCLUDE_DIR})
 
 if(MSVC)
 	get_target_property(options aux_math COMPILE_OPTIONS)
diff --git a/src/xrt/auxiliary/tracking/CMakeLists.txt b/src/xrt/auxiliary/tracking/CMakeLists.txt
index 4f13ea7c16..ed35980b1f 100644
--- a/src/xrt/auxiliary/tracking/CMakeLists.txt
+++ b/src/xrt/auxiliary/tracking/CMakeLists.txt
@@ -23,7 +23,6 @@ target_link_libraries(
 		xrt-external-hungarian
 		xrt-optimized-math
 	)
-target_include_directories(aux_tracking SYSTEM PRIVATE ${EIGEN3_INCLUDE_DIR})
 
 if(XRT_HAVE_OPENCV)
 	target_sources(
diff --git a/src/xrt/auxiliary/util/CMakeLists.txt b/src/xrt/auxiliary/util/CMakeLists.txt
index f915c7c0a0..4d39e4db4d 100644
--- a/src/xrt/auxiliary/util/CMakeLists.txt
+++ b/src/xrt/auxiliary/util/CMakeLists.txt
@@ -166,9 +166,6 @@ if(ANDROID)
 	target_link_libraries(aux_util PUBLIC ${ANDROID_LOG_LIBRARY})
 endif()
 
-# Internal dependency and doesn't bring in any DSO.
-target_include_directories(aux_util PRIVATE ${EIGEN3_INCLUDE_DIR})
-
 ####
 # Debug UI library
 #
diff --git a/src/xrt/drivers/CMakeLists.txt b/src/xrt/drivers/CMakeLists.txt
index 90dc4970f1..3ad8359447 100644
--- a/src/xrt/drivers/CMakeLists.txt
+++ b/src/xrt/drivers/CMakeLists.txt
@@ -279,7 +279,6 @@ if(XRT_BUILD_DRIVER_RIFT_S)
 		rift_s/rift_s.c
 		rift_s/rift_s.h
 		)
-	target_include_directories(drv_rift_s SYSTEM PRIVATE ${EIGEN3_INCLUDE_DIR})
 	target_link_libraries(
 		drv_rift_s
 		PRIVATE
@@ -354,7 +353,7 @@ if(XRT_BUILD_DRIVER_HANDTRACKING)
 			hand_async
 		)
 
-	target_include_directories(drv_ht PRIVATE ${OpenCV_INCLUDE_DIRS} ${EIGEN3_INCLUDE_DIR})
+	target_include_directories(drv_ht PRIVATE ${OpenCV_INCLUDE_DIRS})
 	list(APPEND ENABLED_DRIVERS ht)
 endif()
 
diff --git a/src/xrt/targets/openxr_android/build.gradle b/src/xrt/targets/openxr_android/build.gradle
index 434efca8e5..ea68b8cab1 100644
--- a/src/xrt/targets/openxr_android/build.gradle
+++ b/src/xrt/targets/openxr_android/build.gradle
@@ -81,11 +81,11 @@ tasks.register('unpackEigen', Copy) {
     into eigenUnpackDir
 }
 
-if (!(new File(project.file(project.eigenIncludeDir), "Eigen/Core")).exists()) {
-    println "project.eigenIncludeDir not set or not valid, so downloading Eigen at build time"
-    project.ext.eigenIncludeDir = "${eigenUnpackDir}/eigen-${project.eigenFetchVersion}"
+if (!(new File(project.file(project.eigenCMakeDir), "Eigen3Config.cmake")).exists()) {
+    println "project.eigenCMakeDir not set or not valid, so downloading Eigen at build time"
+    project.ext.eigenCMakeDir = "${eigenUnpackDir}/eigen-${project.eigenFetchVersion}/cmake"
 } else {
-    println "Using Eigen as specified/detected in project.eigenIncludeDir: ${project.eigenIncludeDir}"
+    println "Using Eigen as specified/detected in project.eigenCMakeDir: ${project.eigenCMakeDir}"
     downloadEigen.enabled = false
     unpackEigen.enabled = false
 }
@@ -176,7 +176,7 @@ android {
 
         externalNativeBuild {
             cmake {
-                arguments "-DEIGEN3_INCLUDE_DIR=${project.eigenIncludeDir}",
+                arguments "-DEigen3_DIR=${project.eigenCMakeDir}",
                     "-DANDROID_PLATFORM=${project.sharedMinSdk}",
                     "-DANDROID_STL=${project.stl}",
                     "-DANDROID_ARM_NEON=TRUE"
diff --git a/src/xrt/tracking/hand/mercury/CMakeLists.txt b/src/xrt/tracking/hand/mercury/CMakeLists.txt
index b30575047a..9ac7b8cbad 100644
--- a/src/xrt/tracking/hand/mercury/CMakeLists.txt
+++ b/src/xrt/tracking/hand/mercury/CMakeLists.txt
@@ -12,10 +12,7 @@ add_library(t_ht_mercury_model STATIC hg_model.cpp)
 
 target_link_libraries(t_ht_mercury_model PRIVATE aux_math aux_tracking aux_os aux_util)
 
-target_include_directories(
-	t_ht_mercury_model SYSTEM PRIVATE ${OpenCV_INCLUDE_DIRS} ${EIGEN3_INCLUDE_DIR}
-	)
-
+target_include_directories(t_ht_mercury_model SYSTEM PRIVATE ${OpenCV_INCLUDE_DIRS})
 target_link_libraries(
 	t_ht_mercury_model
 	PRIVATE
@@ -33,9 +30,7 @@ add_library(t_ht_mercury_distorter STATIC hg_image_distorter.cpp)
 
 target_link_libraries(t_ht_mercury_distorter PRIVATE aux_math aux_tracking aux_os aux_util)
 
-target_include_directories(
-	t_ht_mercury_distorter SYSTEM PRIVATE ${OpenCV_INCLUDE_DIRS} ${EIGEN3_INCLUDE_DIR}
-	)
+target_include_directories(t_ht_mercury_distorter SYSTEM PRIVATE ${OpenCV_INCLUDE_DIRS})
 
 target_link_libraries(
 	t_ht_mercury_distorter
@@ -71,9 +66,7 @@ target_link_libraries(
 target_include_directories(t_ht_mercury INTERFACE ${CMAKE_CURRENT_SOURCE_DIR})
 
 if(XRT_HAVE_OPENCV)
-	target_include_directories(
-		t_ht_mercury SYSTEM PRIVATE ${OpenCV_INCLUDE_DIRS} ${EIGEN3_INCLUDE_DIR}
-		)
+	target_include_directories(t_ht_mercury SYSTEM PRIVATE ${OpenCV_INCLUDE_DIRS})
 	target_link_libraries(t_ht_mercury PUBLIC ${OpenCV_LIBRARIES})
 endif()
 
diff --git a/src/xrt/tracking/hand/mercury/kine_lm/CMakeLists.txt b/src/xrt/tracking/hand/mercury/kine_lm/CMakeLists.txt
index 8fa42dc1a4..90a2a329a1 100644
--- a/src/xrt/tracking/hand/mercury/kine_lm/CMakeLists.txt
+++ b/src/xrt/tracking/hand/mercury/kine_lm/CMakeLists.txt
@@ -19,8 +19,6 @@ target_link_libraries(
 		xrt-optimized-math
 	)
 
-target_include_directories(t_ht_mercury_kine_lm SYSTEM PRIVATE ${EIGEN3_INCLUDE_DIR})
-
 if(${CMAKE_CXX_COMPILER_ID} STREQUAL "Clang")
 	target_compile_options(t_ht_mercury_kine_lm PRIVATE -ftemplate-backtrace-limit=20)
 endif()
diff --git a/tests/CMakeLists.txt b/tests/CMakeLists.txt
index acffe8a360..1e6686abc6 100644
--- a/tests/CMakeLists.txt
+++ b/tests/CMakeLists.txt
@@ -68,9 +68,6 @@ target_link_libraries(tests_quat_change_of_basis PRIVATE aux_math)
 target_link_libraries(tests_quat_swing_twist PRIVATE aux_math)
 target_link_libraries(tests_vec3_angle PRIVATE aux_math)
 
-target_include_directories(tests_quat_change_of_basis SYSTEM PRIVATE ${EIGEN3_INCLUDE_DIR})
-target_include_directories(tests_quat_swing_twist SYSTEM PRIVATE ${EIGEN3_INCLUDE_DIR})
-
 if(XRT_BUILD_DRIVER_HANDTRACKING)
 	target_link_libraries(
 		tests_levenbergmarquardt
-- 
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