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7875 :: Nim on Android error regarding size of a pointer

• 19 (orginal) [2021-04-28T08:30:32+02:00] view original

  Hi im getting this error when i cross compile to android:

  
  In file included from C:\Users\XXXX\develkinc\Shader-Kinc\Sources\@m..@sKinc@sSources@skinc@sgraphics4@sg4.nim.c:9:
  C:\Users\XXXX\nim-1.4.2\lib\nimbase.h:542:1: error: static_assert failed due to requirement 'sizeof(int) == sizeof(void *) && 32 == sizeof(int) * 8' ""
  Run

  comes from this line in nimbase.h:

  
  // Test to see if Nim and the C compiler agree on the size of a pointer.
  NIM_STATIC_ASSERT(sizeof(NI) == sizeof(void*) && NIM_INTBITS == sizeof(NI)*8, "");
  Run

  using this build command:

  
  nim c -c --cpu:arm --os:android -d:androidNDK --noMain:on --header:nimlib/nmain.h nimlib/nmain.nim
  Run

---

• dom96 (orginal) [2021-04-28T11:53:13+02:00] view original

  Android Studio will build your code for different CPU architectures (not just arm). So you need a way to tell it to pick the right arch.

  Here is my Android.mk file showing how I did it:

  
  LOCAL_PATH := $(call my-dir)
  
  # To build these I downloaded the openssl source code, followed NOTES.ANDROID.
  # Also used the commands here to get rid of versions in .so: https://github.com/openssl/openssl/issues/3902
  # This tutorial was also somewhat useful: https://proandroiddev.com/tutorial-compile-openssl-to-1-1-1-for-android-application-87137968fee
  #
  # https://developer.android.com/ndk/guides/prebuilts#sa
  include $(CLEAR_VARS)
  LOCAL_MODULE := libssl
  LOCAL_SRC_FILES := $(LOCAL_PATH)/dlls/$(TARGET_ARCH_ABI)/libssl.so
  include $(PREBUILT_SHARED_LIBRARY)
  
  include $(CLEAR_VARS)
  LOCAL_MODULE := libcrypto
  LOCAL_SRC_FILES := $(LOCAL_PATH)/dlls/$(TARGET_ARCH_ABI)/libcrypto.so
  include $(PREBUILT_SHARED_LIBRARY)
  
  include $(CLEAR_VARS)
  
  LOCAL_MODULE := main
  
  SDL_PATH := ../SDL
  
  LOCAL_C_INCLUDES := $(LOCAL_PATH)/$(SDL_PATH)/include $(LOCAL_PATH)/../SDL2_image/
  
  # https://developer.android.com/ndk/guides/android_mk#target_arch
  FILE_LIST := $(wildcard $(LOCAL_PATH)/$(TARGET_ARCH)/*.c)
  LOCAL_SRC_FILES := $(FILE_LIST:$(LOCAL_PATH)/%=%)
  
  LOCAL_SHARED_LIBRARIES := SDL2 SDL2_image libssl libcrypto
  
  # See https://developer.android.com/ndk/guides/stable_apis for some of the APIs we can link against.
  LOCAL_LDLIBS := -v -lGLESv1_CM -lGLESv2 -llog
  
  include $(BUILD_SHARED_LIBRARY)
  Run

  The important part is the line beginning with FILE_LIST.

---

• 19 (orginal) [2021-04-28T13:56:37+02:00] view original

  Thank you so much! I compiled with --cpu:amd64 and it worked but it's not ideal! I couldn't find Android.mk file in my project so I'll investigate further, I have a CMAKE and some build.gradles

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• 19 (orginal) [2021-04-29T10:21:52+02:00] view original

  Okay so Im trying to make nim generate the correct sizes again but for another project.

  I'm trying to figure it out and I hit a wall.

  This is the compiler build command in Android Studio (shortened for brevity):

  
  C:/NVPACK/android-sdk-windows/ndk/21.0.6113669/toolchains/llvm/prebuilt/windows-x86_64/bin/clang.exe
  --target=aarch64-none-linux-android21
  --gcc-toolchain=C:/NVPACK/android-sdk-windows/ndk/21.0.6113669/toolchains/llvm/prebuilt/windows-x86_64
  --sysroot=C:/NVPACK/android-sdk-windows/ndk/21.0.6113669/toolchains/llvm/prebuilt/windows-x86_64/sysroot
  Run

  Reading stuff from this older post i concluded that i must setup the cross compiler for Nim to generate the correct C code for this project: https://forum.nim-lang.org/t/1866

  But I didn't know if this was the right thing to do nor how to do it.

  nim.cfg:

  
  # Examples of how to setup a cross-compiler:
  arm64.linux.clang.path="C:/NVPACK/android-sdk-windows/ndk/21.0.6113669/toolchains/llvm/prebuilt/windows-x86_64/bin/"
  arm64.linux.clang.exe=
  Run

  Is this the correct thing to do? Sorry this is the first time I do this ^_^

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