Fix build with CMake 4

Author: Tabby

CMakeLists.txt

@@ -8,6 +8,11 @@ option(ENABLE_FRONTEND_API "Use obs-frontend-api for UI functionality" ON)
 option(ENABLE_QT "Use Qt functionality" ON)
 option(ENABLE_TESTS "Enable tests" OFF)
 
+if(CMAKE_MAJOR_VERSION EQUAL 4)
+  message(STATUS "CMake 4 detected")
+  set(CMAKE_POLICY_VERSION_MINIMUM 3.5)
+endif()
+
 include(compilerconfig)
 include(defaults)
 include(helpers)

README.md

@@ -156,8 +156,6 @@ For other distros where you can't use the CI build script, you can build the plu
     cmake -B build-dir --preset linux-x86_64 -DUSE_SYSTEM_CURL=ON -DUSE_SYSTEM_ICU=ON -DCMAKE_INSTALL_PREFIX=./output_dir
     ```
 
-    Note: if using CMake 4.0.0 or higher you may also need to add `-DCMAKE_POLICY_VERSION_MINIMUM=3.5`. If possible, please use a version of CMake that is older than 4.0.0, as many of the dependencies used by this plugin still have their minimum versions set to very old versions of CMake.
-
 1. Build the plugin and copy the files to the output directory
 
     ```sh

cmake/BuildCTranslate2.cmake

@@ -62,7 +62,11 @@ else()
   # build cpu_features from source
   set(CPU_FEATURES_VERSION "0.9.0")
   set(CPU_FEATURES_URL "https://github.com/google/cpu_features.git")
-  set(CPU_FEATURES_CMAKE_ARGS -DBUILD_TESTS=OFF -DBUILD_SHARED_LIBS=OFF)
+  if(CMAKE_MAJOR_VERSION EQUAL 4)
+    set(CPU_FEATURES_CMAKE_ARGS -DBUILD_TESTING=OFF -DBUILD_SHARED_LIBS=OFF -DCMAKE_POLICY_VERSION_MINIMUM=3.5)
+  else()
+    set(CPU_FEATURES_CMAKE_ARGS -DBUILD_TESTING=OFF -DBUILD_SHARED_LIBS=OFF)
+  endif()
   ExternalProject_Add(
     cpu_features_build
     GIT_REPOSITORY ${CPU_FEATURES_URL}
@@ -95,7 +99,12 @@ else()
   set(CT2_URL "https://github.com/OpenNMT/CTranslate2.git")
   set(CT2_OPENBLAS_CMAKE_ARGS -DWITH_OPENBLAS=OFF)
 
-  set(CT2_CMAKE_PLATFORM_OPTIONS -DBUILD_SHARED_LIBS=OFF -DOPENMP_RUNTIME=NONE -DCMAKE_POSITION_INDEPENDENT_CODE=ON)
+  if(CMAKE_MAJOR_VERSION EQUAL 4)
+    set(CT2_CMAKE_PLATFORM_OPTIONS -DBUILD_SHARED_LIBS=OFF -DOPENMP_RUNTIME=NONE -DCMAKE_POSITION_INDEPENDENT_CODE=ON
+                                   -DCMAKE_POLICY_VERSION_MINIMUM=3.5)
+  else()
+    set(CT2_CMAKE_PLATFORM_OPTIONS -DBUILD_SHARED_LIBS=OFF -DOPENMP_RUNTIME=NONE -DCMAKE_POSITION_INDEPENDENT_CODE=ON)
+  endif()
   set(CT2_LIB_INSTALL_LOCATION
       ${CMAKE_INSTALL_LIBDIR}/${CMAKE_SHARED_LIBRARY_PREFIX}ctranslate2${CMAKE_STATIC_LIBRARY_SUFFIX})
 
@@ -123,6 +132,7 @@ else()
                -DWITH_COVERAGE=OFF
                -DWITH_PROFILING=OFF
                -DBUILD_CLI=OFF
+               -DBUILD_TESTS=OFF
                ${CT2_OPENBLAS_CMAKE_ARGS}
                ${CT2_CMAKE_PLATFORM_OPTIONS}
     LOG_CONFIGURE ON

cmake/BuildSentencepiece.cmake

@@ -48,7 +48,7 @@ else()
   ExternalProject_Add(
     sentencepiece_build
     GIT_REPOSITORY ${SP_URL}
-    GIT_TAG v0.1.99
+    GIT_TAG v0.2.1
     BUILD_COMMAND ${CMAKE_COMMAND} --build <BINARY_DIR> --config ${CMAKE_BUILD_TYPE}
     CMAKE_GENERATOR ${CMAKE_GENERATOR}
     INSTALL_COMMAND ${CMAKE_COMMAND} --install <BINARY_DIR> --config ${CMAKE_BUILD_TYPE}