cmake : adapt native lib linking for Android

Author: amqdn

ggml/src/CMakeLists.txt

@@ -1127,7 +1127,7 @@ if (CMAKE_OSX_ARCHITECTURES      STREQUAL "arm64" OR
             endif()
         endif()
         if (${CMAKE_SYSTEM_PROCESSOR} MATCHES "armv8")
-            # Android arm64-v8a
+            # Android arm64-v8a <- NOT REACHED; arm64-v8a and armv8 differ
             # Raspberry Pi 3, 4, Zero 2 (32-bit)
             list(APPEND ARCH_FLAGS -mno-unaligned-access)
         endif()
@@ -1341,11 +1341,15 @@ list(APPEND GGML_EXTRA_LIBS_PRIVATE Threads::Threads)
 
 find_library(MATH_LIBRARY m)
 if (MATH_LIBRARY)
-    if (NOT WIN32 OR NOT GGML_SYCL)
+    if (NOT WIN32 OR NOT GGML_SYCL OR NOT CMAKE_SYSTEM_NAME MATCHES "Android")
         list(APPEND GGML_EXTRA_LIBS_PRIVATE m)
     endif()
 endif()
 
+if (CMAKE_SYSTEM_NAME MATCHES "Android")
+    list(APPEND GGML_EXTRA_LIBS_PRIVATE dl) # Must be linked explicitly
+endif()
+
 list(REMOVE_DUPLICATES GGML_EXTRA_LIBS_PRIVATE)
 list(REMOVE_DUPLICATES GGML_EXTRA_LIBS_PUBLIC)
 target_link_libraries(ggml PRIVATE ${GGML_EXTRA_LIBS_PRIVATE} PUBLIC ${GGML_EXTRA_LIBS_PUBLIC})