cmake : fix Vulkan build (#5182)

Author: netrunnereve

CMakeLists.txt

@@ -422,7 +422,13 @@ if (LLAMA_VULKAN)
     if (Vulkan_FOUND)
         message(STATUS "Vulkan found")
 
+        set(GGML_HEADERS_VULKAN ggml-vulkan.h)
+        set(GGML_SOURCES_VULKAN ggml-vulkan.cpp)
+
         add_library(ggml-vulkan STATIC ggml-vulkan.cpp ggml-vulkan.h)
+        if (BUILD_SHARED_LIBS)
+            set_target_properties(ggml-vulkan PROPERTIES POSITION_INDEPENDENT_CODE ON)
+        endif()
         target_link_libraries(ggml-vulkan PRIVATE Vulkan::Vulkan)
 
         add_compile_definitions(GGML_USE_VULKAN)
@@ -848,6 +854,7 @@ add_library(ggml OBJECT
             ggml-quants.h
             ${GGML_SOURCES_CUDA}   ${GGML_HEADERS_CUDA}
             ${GGML_SOURCES_OPENCL} ${GGML_HEADERS_OPENCL}
+            ${GGML_SOURCES_VULKAN} ${GGML_HEADERS_VULKAN}
             ${GGML_SOURCES_METAL}  ${GGML_HEADERS_METAL}
             ${GGML_SOURCES_MPI}    ${GGML_HEADERS_MPI}
             ${GGML_SOURCES_EXTRA}  ${GGML_HEADERS_EXTRA}
@@ -928,7 +935,7 @@ install(FILES ${CMAKE_CURRENT_BINARY_DIR}/LlamaConfig.cmake
         DESTINATION ${CMAKE_INSTALL_LIBDIR}/cmake/Llama)
 
 set(GGML_PUBLIC_HEADERS "ggml.h" "ggml-alloc.h" "ggml-backend.h"
-        "${GGML_HEADERS_CUDA}" "${GGML_HEADERS_OPENCL}"
+        "${GGML_HEADERS_CUDA}" "${GGML_HEADERS_OPENCL}" "${GGML_HEADERS_VULKAN}"
         "${GGML_HEADERS_METAL}" "${GGML_HEADERS_MPI}" "${GGML_HEADERS_EXTRA}")
 
 set_target_properties(ggml PROPERTIES PUBLIC_HEADER "${GGML_PUBLIC_HEADERS}")