File 0001-Cleanup-library-build-make-static-library-optional.patch of Package flann

From 616a0ecb069847303aec63a9404032e9388fa774 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Stefan=20Br=C3=BCns?= <stefan.bruens@rwth-aachen.de>
Date: Sun, 11 Sep 2022 19:21:41 +0200
Subject: [PATCH] Cleanup library build, make static library optional

Build the shared library on Linux the same way as on Windows, i.e.
compile the sources individually for static and shared libs.

This removes the "FLANN_STATIC" compile definition from the shared
library build (confusing, albeit without any effect on Linux), and
avoids any linker trickery.

Also allow to disable build and installation of the static libraries
completely, as these are often unwanted on Linux distributions.

Fixes flann-lib#498.
See flann-lib#369.
---
 src/cpp/CMakeLists.txt | 71 ++++++++++++++++++------------------------
 1 file changed, 30 insertions(+), 41 deletions(-)

diff --git a/src/cpp/CMakeLists.txt b/src/cpp/CMakeLists.txt
index d8bff04..1ebcecc 100644
--- a/src/cpp/CMakeLists.txt
+++ b/src/cpp/CMakeLists.txt
@@ -13,7 +13,14 @@ target_link_libraries(flann_cpp_s PUBLIC ${LZ4_LINK_LIBRARIES})
 if(CMAKE_COMPILER_IS_GNUCC OR CMAKE_COMPILER_IS_CLANG)
     set_target_properties(flann_cpp_s PROPERTIES COMPILE_FLAGS -fPIC)
 endif()
-set_property(TARGET flann_cpp_s PROPERTY COMPILE_DEFINITIONS FLANN_STATIC FLANN_USE_CUDA)
+if (CMAKE_BUILD_STATIC_LIBS)
+    list(APPEND flann_install_targets flann_cpp_s)
+else()
+    set_target_properties(flann_cpp_s PROPERTIES EXCLUDE_FROM_ALL true)
+endif()
+
+add_library(flann_cpp SHARED ${CPP_SOURCES})
+set(flann_install_targets flann_cpp)
 
 if (BUILD_CUDA_LIB)
     SET(CUDA_NVCC_FLAGS "${CUDA_NVCC_FLAGS};-DFLANN_USE_CUDA")
@@ -27,29 +34,27 @@ if (BUILD_CUDA_LIB)
     endif()
     cuda_add_library(flann_cuda_s STATIC ${CU_SOURCES})
     set_property(TARGET flann_cuda_s PROPERTY COMPILE_DEFINITIONS FLANN_STATIC)
+    if (CMAKE_BUILD_STATIC_LIBS)
+        list(APPEND flann_install_targets flann_cuda_s)
+    else()
+        set_target_properties(flann_cuda_s PROPERTIES EXCLUDE_FROM_ALL true)
+    endif()
+
+    cuda_add_library(flann_cuda SHARED ${CU_SOURCES})
+    list(APPEND flann_install_targets flann_cuda)
+    set_property(TARGET flann_cpp PROPERTY COMPILE_DEFINITIONS FLANN_USE_CUDA)
+    set_property(TARGET flann_cpp_s PROPERTY COMPILE_DEFINITIONS FLANN_STATIC FLANN_USE_CUDA)
+else()
+    set_property(TARGET flann_cpp_s PROPERTY COMPILE_DEFINITIONS FLANN_STATIC)
 endif()
 
 if(CMAKE_SYSTEM_NAME STREQUAL "Linux" AND CMAKE_COMPILER_IS_GNUCC)
-    add_library(flann_cpp SHARED dummy.c)
     set_target_properties(flann_cpp PROPERTIES LINKER_LANGUAGE CXX)
-    target_link_libraries(flann_cpp -Wl,-whole-archive flann_cpp_s -Wl,-no-whole-archive)
     target_link_libraries(flann_cpp PUBLIC ${LZ4_LINK_LIBRARIES})
-
-    if (BUILD_CUDA_LIB)
-	cuda_add_library(flann_cuda SHARED dummy.c)
-        set_target_properties(flann_cuda PROPERTIES LINKER_LANGUAGE CXX)
-        target_link_libraries(flann_cuda -Wl,-whole-archive flann_cuda_s -Wl,-no-whole-archive)
-        set_property(TARGET flann_cpp_s PROPERTY COMPILE_DEFINITIONS FLANN_USE_CUDA)
-    endif()
 else()
-    add_library(flann_cpp SHARED ${CPP_SOURCES})
     target_link_libraries(flann_cpp PUBLIC ${LZ4_LINK_LIBRARIES})
     # export lz4 headers, so that MSVC to creates flann_cpp.lib
     set_target_properties(flann_cpp PROPERTIES WINDOWS_EXPORT_ALL_SYMBOLS YES)
-    if (BUILD_CUDA_LIB)
-	cuda_add_library(flann_cuda SHARED ${CU_SOURCES})
-        set_property(TARGET flann_cpp PROPERTY COMPILE_DEFINITIONS FLANN_USE_CUDA)
-    endif()
 endif()
 
 set_target_properties(flann_cpp PROPERTIES
@@ -85,14 +91,17 @@ if (BUILD_C_BINDINGS)
         set_target_properties(flann_s PROPERTIES COMPILE_FLAGS -fPIC)
     endif()
     set_property(TARGET flann_s PROPERTY COMPILE_DEFINITIONS FLANN_STATIC)
+    if (CMAKE_BUILD_STATIC_LIBS)
+        list(APPEND flann_install_targets flann_s)
+    else()
+        set_target_properties(flann_s PROPERTIES EXCLUDE_FROM_ALL true)
+    endif()
 
+    add_library(flann SHARED ${C_SOURCES})
+    list(APPEND flann_install_targets flann)
     if(CMAKE_SYSTEM_NAME STREQUAL "Linux" AND CMAKE_COMPILER_IS_GNUCC)
-        add_library(flann SHARED dummy.c)
-        set_target_properties(flann PROPERTIES LINKER_LANGUAGE CXX)
-        target_link_libraries(flann -Wl,-whole-archive flann_s -Wl,-no-whole-archive)
         target_link_libraries(flann PUBLIC ${LZ4_LINK_LIBRARIES})
     else()
-        add_library(flann SHARED ${C_SOURCES})
         target_link_libraries(flann PUBLIC ${LZ4_LINK_LIBRARIES})
 
         if(MINGW AND OPENMP_FOUND)
@@ -117,7 +127,7 @@ endif(WIN32)
 
 
 install (
-    TARGETS flann_cpp flann_cpp_s
+    TARGETS ${flann_install_targets}
     EXPORT ${targets_export_name}
     INCLUDES DESTINATION include
     RUNTIME DESTINATION bin
@@ -125,27 +135,6 @@ install (
     ARCHIVE DESTINATION ${FLANN_LIB_INSTALL_DIR}
 )
 
-if (BUILD_CUDA_LIB)
-    install (
-        TARGETS flann_cuda flann_cuda_s
-        EXPORT ${targets_export_name}
-        INCLUDES DESTINATION include
-        RUNTIME DESTINATION bin
-        LIBRARY DESTINATION ${FLANN_LIB_INSTALL_DIR}
-        ARCHIVE DESTINATION ${FLANN_LIB_INSTALL_DIR}
-    )
-endif()
-
-if (BUILD_C_BINDINGS)
-    install (
-        TARGETS flann flann_s
-        EXPORT ${targets_export_name}
-        INCLUDES DESTINATION include
-        RUNTIME DESTINATION bin
-        LIBRARY DESTINATION ${FLANN_LIB_INSTALL_DIR}
-        ARCHIVE DESTINATION ${FLANN_LIB_INSTALL_DIR}
-    )
-endif()
 
 install (
     DIRECTORY flann
-- 
2.37.3