IssueTracker

The root cause is "strip" on macOS and Linux are not the same and the result is that I cannot compile native library with my LLVM pass file because of missing symbol.

As we known, NDK comes from the toolchain. For example, ndk-r20 comes from clang-r346389c. Hash of r346389c and ndk-r20 are the same.
```
➜  ~ cat Android/Sdk/ndk/20.0.5594570/toolchains/llvm/prebuilt/linux-x86_64/AndroidVersion.txt
8.0.7
based on r346389c
```

And clang-r346389c comes from https://android.googlesource.com/toolchain/llvm_android/ .  The `build.py` copy `stage2-install/bin/clang` to clang-r346389c and `strip` it.

There is a demo pass in NDK, which locates Android/Sdk/ndk/20.0.5594570/toolchains/llvm/prebuilt/linux-x86_64/lib64/LLVMHello.so. We can use the following command to load it.

```
➜  ~ cat /tmp/test.c
#include<stdio.h>
int main(){
printf("HelloWorld\n");
return 0;
}
➜  ~ Android/Sdk/ndk/20.0.5594570/toolchains/llvm/prebuilt/linux-x86_64/bin/clang -Xclang -load -Xclang Android/Sdk/ndk/20.0.5594570/toolchains/llvm/prebuilt/linux-x86_64/lib64/LLVMHello.so /tmp/test.c
➜  ~ ./a.out
HelloWorld
```

When I test on macOS, error occurs.

```
➜  /tmp $ANDROID_NDK/20.0.5594570/toolchains/llvm/prebuilt/darwin-x86_64/bin/clang -Xclang -load -Xclang $ANDROID_NDK/20.0.5594570/toolchains/llvm/prebuilt/darwin-x86_64/lib64/LLVMHello.dylib test.c
error: unable to load plugin '/Users/XXXXXX/Library/Android/sdk/ndk/20.0.5594570/toolchains/llvm/prebuilt/darwin-x86_64/lib64/LLVMHello.dylib':
      'dlopen(/Users/XXXXXX/Library/Android/sdk/ndk/20.0.5594570/toolchains/llvm/prebuilt/darwin-x86_64/lib64/LLVMHello.dylib, 9): Symbol not found:
      __ZN4llvm12FunctionPass17assignPassManagerERNS_7PMStackENS_15PassManagerTypeE
  Referenced from: /Users/XXXXXX/Library/Android/sdk/ndk/20.0.5594570/toolchains/llvm/prebuilt/darwin-x86_64/lib64/LLVMHello.dylib
  Expected in: flat namespace
 in /Users/XXXXXX/Library/Android/sdk/ndk/20.0.5594570/toolchains/llvm/prebuilt/darwin-x86_64/lib64/LLVMHello.dylib'
```

Another case is that:
I follow this https://android.googlesource.com/toolchain/llvm_android/+/master/README.md and build master branch on macOS(need 32bit support).

```
➜  out lsa install/darwin-x86/clang-dev/bin/clang-10
-rwxr-xr-x  1 xunyou  staff    64M 10 22 06:19 install/darwin-x86/clang-dev/bin/clang-10
➜  out lsa stage2-install/bin/clang-10              
-rwxrw-rw-  1 xunyou  wheel    77M 10 22 05:55 stage2-install/bin/clang-10
```
I do the same test for clang-10 before strip and after strip, the result is that:
clang-10 can load plugin before strip;
clang-10 can NOT load plugin after strip;

So I think strip on macOS is not suitable.
https://android.googlesource.com/toolchain/llvm_android/+/refs/heads/master/build.py
```
    for bin_filename in os.listdir(bin_dir):
        binary = os.path.join(bin_dir, bin_filename)
        if os.path.isfile(binary):
            if bin_filename not in necessary_bin_files:
                remove(binary)
            elif strip and bin_filename not in script_bins:
                check_call(['strip', binary])
```

I think we should not strip the llvm-symbols in clang.