export NDK_ROOT=~/android-ndk-r18b

${NDK_ROOT}/toolchains/llvm/prebuilt/linux-x86_64/bin/clang
  --target=x86_64-none-linux-android
  --gcc-toolchain=${NDK_ROOT}/toolchains/x86_64-4.9/prebuilt/linux-x86_64
  --sysroot=${NDK_ROOT}/sysroot
  -isystem ${NDK_ROOT}/sysroot/usr/include/x86_64-linux-android
  -pie -o  hello.c.o -c hello.c

${NDK_ROOT}/toolchains/llvm/prebuilt/linux-x86_64/bin/clang
  --target=x86_64-none-linux-android
  --gcc-toolchain=${NDK_ROOT}/toolchains/x86_64-4.9/prebuilt/linux-x86_64
  --sysroot  ${NDK_ROOT}/platforms/android-21/arch-x86_64
  -pie hello.c.o -o hello

  ${NDK_ROOT}/toolchains/llvm/prebuilt/darwin-x86_64/bin/clang \
  --target=armv7-none-linux-androideabi \
  --gcc-toolchain=${NDK_ROOT}/toolchains/arm-linux-androideabi-4.9 \
  --sysroot=${NDK_ROOT}/sysroot \
  -isystem ${NDK_ROOT}/sysroot/usr/include/arm-linux-androideabi \
  -pie \
  -o  hello.c.o -c hello.c

${NDK_ROOT}/toolchains/llvm/prebuilt/linux-x86_64/bin/clang
  --target=armv7-none-linux-androideabi
  --gcc-toolchain=${NDK_ROOT}/toolchains/arm-linux-androideabi-4.9/...
  --sysroot  ${NDK_ROOT}/platforms/android-21/arch-arm
  -pie hello.c.o -o hello

class A
{
public:
    int m_a;
};

class B:public A{
public:
    int m_b;
};

class C:public A{
public:
    int m_c;
};

class D:public B,public C{
public:
    int m_d;
};

*** Dumping AST Record Layout
         0 | class A
         0 |   int m_a
           | [sizeof=4, dsize=4, align=4,
           |  nvsize=4, nvalign=4]

*** Dumping AST Record Layout
         0 | class B
         0 |   class A (base)
         0 |     int m_a
         4 |   int m_b
           | [sizeof=8, dsize=8, align=4,
           |  nvsize=8, nvalign=4]

*** Dumping AST Record Layout
         0 | class C
         0 |   class A (base)
         0 |     int m_a
         4 |   int m_c
           | [sizeof=8, dsize=8, align=4,
           |  nvsize=8, nvalign=4]

*** Dumping AST Record Layout
         0 | class D
         0 |   class B (base)
         0 |     class A (base)
         0 |       int m_a
         4 |     int m_b
         8 |   class C (base)
         8 |     class A (base)
         8 |       int m_a
        12 |     int m_c
        16 |   int m_d
           | [sizeof=20, dsize=20, align=4,
           |  nvsize=20, nvalign=4]

*** Dumping AST Record Layout
         0 | class A
         0 |   (A vtable pointer)
         8 |   int m_a
           | [sizeof=16, dsize=12, align=8,
           |  nvsize=12, nvalign=8]

*** Dumping AST Record Layout
         0 | class B
         0 |   class A (primary base)
         0 |     (A vtable pointer)
         8 |     int m_a
        12 |   int m_b
           | [sizeof=16, dsize=16, align=8,
           |  nvsize=16, nvalign=8]

*** Dumping AST Record Layout
         0 | class C
         0 |   class A (primary base)
         0 |     (A vtable pointer)
         8 |     int m_a
        12 |   int m_c
           | [sizeof=16, dsize=16, align=8,
           |  nvsize=16, nvalign=8]

*** Dumping AST Record Layout
         0 | class D
         0 |   class B (primary base)
         0 |     class A (primary base)
         0 |       (A vtable pointer)
         8 |       int m_a
        12 |     int m_b
        16 |   class C (base)
        16 |     class A (primary base)
        16 |       (A vtable pointer)
        24 |       int m_a
        28 |     int m_c
        32 |   int m_d
           | [sizeof=40, dsize=36, align=8,
           |  nvsize=36, nvalign=8]

clang -cc1 -fdump-record-layouts -stdlib=libc++ vinherit.cpp
clang -cc1 -emit-llvm -fdump-record-layouts -stdlib=libc++ normal_multi_inherit.cpp

class A
{
public:
    int a;
};

class B:virtual public A{};
class C:virtual public A{};
class D:public B,public C{};

int main(int argc,char* argv[])
{
    D d;
    cout << sizeof(d) << endl;  // 12
    return 0;
}