From a5d66fb4ffcda9024c7fa0ac8e42a164dfe52804 Mon Sep 17 00:00:00 2001
From: Tyler Veness <calcmogul@gmail.com>
Date: Sat, 27 Jun 2026 12:11:54 -0700
Subject: [PATCH] [build] Add CMake option to use system Sleipnir install
 (#9028)

This allows using an alternate version from FetchContent.
---
 CMakeLists.txt                  |  3 ++-
 wpimath/CMakeLists.txt          | 43 +++++++++++++++++++++++----------
 wpimath/wpimath-config.cmake.in |  4 +++
 3 files changed, 36 insertions(+), 14 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index bc832067cb..6c2745e949 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -84,9 +84,10 @@ option(WITH_SIMULATION_MODULES "Build simulation modules" ON)
 option(WITH_BENCHMARK "Build the benchmark project" ON)
 
 # Options for using a package manager (e.g., vcpkg) for certain dependencies.
+option(USE_SYSTEM_EIGEN "Use system Eigen" OFF)
 option(USE_SYSTEM_FMTLIB "Use system fmtlib" OFF)
 option(USE_SYSTEM_LIBUV "Use system libuv" OFF)
-option(USE_SYSTEM_EIGEN "Use system eigen" OFF)
+option(USE_SYSTEM_SLEIPNIR "Use system Sleipnir" OFF)
 option(USE_LINKED_AVAHI "Use directly linked Avahi instead of loading at runtime" OFF)
 
 # Options for compilation flags.
diff --git a/wpimath/CMakeLists.txt b/wpimath/CMakeLists.txt
index c74a443dab..5df3a1aab5 100644
--- a/wpimath/CMakeLists.txt
+++ b/wpimath/CMakeLists.txt
@@ -20,13 +20,11 @@ file(
     src/main/native/cpp/jni/optimization/ProblemJNI.cpp
 )
 
-file(
-    GLOB_RECURSE wpimath_native_src
-    src/main/native/cpp/*.cpp
-    src/main/native/thirdparty/sleipnir/src/*.cpp
-)
+file(GLOB_RECURSE wpimath_native_src src/main/native/cpp/*.cpp)
 list(REMOVE_ITEM wpimath_native_src ${wpimath_jni_src})
 
+file(GLOB_RECURSE sleipnir_native_src src/main/native/thirdparty/sleipnir/src/*.cpp)
+
 set(CMAKE_WINDOWS_EXPORT_ALL_SYMBOLS FALSE)
 
 file(GLOB_RECURSE wpimath_protobuf_native_src src/generated/main/native/cpp/wpimath/protobuf/*.cpp)
@@ -86,19 +84,38 @@ else()
     target_link_libraries(wpimath Eigen3::Eigen)
 endif()
 
-install(
-    DIRECTORY src/main/native/thirdparty/gcem/include/ src/main/native/thirdparty/sleipnir/include/
-    DESTINATION "${include_dest}/wpimath"
-)
+install(DIRECTORY src/main/native/thirdparty/gcem/include/ DESTINATION "${include_dest}/wpimath")
 target_include_directories(
     wpimath
     SYSTEM
-    PUBLIC
-        $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/src/main/native/thirdparty/gcem/include>
-        $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/src/main/native/thirdparty/sleipnir/include>
-        $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/src/main/native/thirdparty/sleipnir/src>
+    PUBLIC $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/src/main/native/thirdparty/gcem/include>
 )
 
+if(NOT USE_SYSTEM_SLEIPNIR)
+    target_sources(wpimath PRIVATE ${sleipnir_native_src})
+    install(
+        DIRECTORY src/main/native/thirdparty/sleipnir/include/
+        DESTINATION "${include_dest}/wpimath"
+    )
+    target_include_directories(
+        wpimath
+        SYSTEM
+        PUBLIC
+            $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/src/main/native/thirdparty/sleipnir/include>
+            $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/src/main/native/thirdparty/sleipnir/src>
+    )
+else()
+    find_package(Sleipnir CONFIG REQUIRED)
+    target_link_libraries(wpimath Sleipnir::Sleipnir)
+    if(MSVC)
+        get_target_property(Sleipnir_includes Sleipnir::Sleipnir INTERFACE_INCLUDE_DIRECTORIES)
+        foreach(dir ${Sleipnir_includes})
+            target_compile_options(wpimath PUBLIC /external:I "${dir}")
+        endforeach()
+        target_compile_options(wpimath PUBLIC /external:W0)
+    endif()
+endif()
+
 install(
     DIRECTORY src/generated/main/native/cpp/
     DESTINATION "${include_dest}/wpimath"
diff --git a/wpimath/wpimath-config.cmake.in b/wpimath/wpimath-config.cmake.in
index 9100d7943d..62daba04cd 100644
--- a/wpimath/wpimath-config.cmake.in
+++ b/wpimath/wpimath-config.cmake.in
@@ -6,5 +6,9 @@ if(@USE_SYSTEM_EIGEN@)
     find_dependency(Eigen3)
 endif()
 
+if(@USE_SYSTEM_SLEIPNIR@)
+  find_dependency(Sleipnir)
+endif()
+
 @FILENAME_DEP_REPLACE@
 include(${SELF_DIR}/wpimath.cmake)