3 ms·

Which is all the ones that matter the most for this discussion due to market share / mindshare.

• pjmlp 4y ago
  Good luck using the C ABI on ChromeOS or Android.
  • saagarjha 4y ago
    Android is Linux-based and has many of the same problems. Chrome OS too if you’re writing to the metal.
    • pjmlp 4y ago
      Good attempt. Android userspace uses Java and can only talk to native code via JNI, which definitely isn't a C ABI. Likewise there isn't any writing to metal on ChromeOS for the official userspace APIs, running Linux (Crostini) implies running a sandboxed version on top of the actual ChromeOS, while Android on ChromeOS not only has the same JNI restrictions, it also is sandboxed without access to host OS. EDIT: I also forgot that ChromeOS and Android expose many of their key APIs to native code via OS IPC, on top of the constraints mentioned above. With endpoints written in a mix of C++, Java and now Rust.
      • cryptonector 4y ago
        JNI is very much a C ABI, yes. I should know, for I've written JNI FFIs more than once. Yes, you can also write JNIs in C++, but you don't have to because JNI's ABI is C not C++, and that is because C++ ABIs were not stable decades ago when JNI was written.
        • pjmlp 4y ago
          JNI isn't a C ABI from the point of view what is being discussed here, it is a marshaling library. You don't do OS syscalls via JNI, rather marshal representation of Java objects for consuptiom from native languages.
          • cryptonector 4y ago
            You clearly haven't written a JNI. JNI is an API between the JVM and C- or C++-coded plugins that can implement native methods. "Native method" means "written in C (or C++)". There's a) a standard interface that C-coded methods must present (depending on their Java signature) and b) a set of utility C functions provided by the JVM. Because these plugins are loaded via `dlopen()`/`LoadLibrary_Ex()`/etc. the JNI API has an ABI. If you don't believe me go look it up. There's a ton of resources on JNI. Here's an example taken from the wikipedia page on JNI: extern "C" JNIEXPORT void JNICALL Java_ClassName_MethodName (JNIEnv *env, jobject obj, jstring javaString) { const char *nativeString = env->GetStringUTFChars(javaString, 0); //Do something with the nativeString env->ReleaseStringUTFChars(javaString, nativeString); }