Add Buffer Logs to ExecuTorchRuntime Exception flow (pytorch#14557) (pytorch#14557)

Summary:

These logs provide detailed context when an error occurs in ET runtime
flow to Android host apps / processes.

Differential Revision: D83113293

Author: psiddh

extension/android/executorch_android/src/main/java/org/pytorch/executorch/ExecutorchRuntimeException.java

@@ -75,7 +75,7 @@ public class ExecutorchRuntimeException extends RuntimeException {
   }
 
   static class ErrorHelper {
-    private static final boolean ENABLE_READ_LOG_BUFFER = false;
+    private static final boolean ENABLE_READ_LOG_BUFFER_LOGS = true;
     // Reusable StringBuilder instance
     private static final StringBuilder sb = new StringBuilder();
 
@@ -94,10 +94,12 @@ static String formatMessage(int errorCode, String details) {
             .append(baseMessage)
             .append(": ")
             .append(details);
-        if (ENABLE_READ_LOG_BUFFER) {
+        if (ENABLE_READ_LOG_BUFFER_LOGS) {
           try {
-            sb.append("\nDetailed Logs:\n");
-            String[] logEntries = readLogBuffer(); // JNI call
+            String[] logEntries = Module.readLogBufferStatic(); // JNI call
+            if (logEntries != null && logEntries.length > 0) {
+              sb.append("\n Detailed logs:\n");
+            }
             formatLogEntries(sb, logEntries);
           } catch (Exception e) {
             sb.append("Failed to retrieve detailed logs: ").append(e.getMessage());
@@ -108,9 +110,6 @@ static String formatMessage(int errorCode, String details) {
       }
     }
 
-    // Native JNI method declaration
-    private static native String[] readLogBuffer();
-
     // Append log entries to the provided StringBuilder
     private static void formatLogEntries(StringBuilder sb, String[] logEntries) {
       if (logEntries == null || logEntries.length == 0) {

extension/android/executorch_android/src/main/java/org/pytorch/executorch/Module.java

@@ -211,6 +211,13 @@ public MethodMetadata getMethodMetadata(String name) {
     return methodMetadata;
   }
 
+  @DoNotStrip
+  private static native String[] readLogBufferStaticNative();
+
+  public static String[] readLogBufferStatic() {
+    return readLogBufferStaticNative();
+  }
+
   /** Retrieve the in-memory log buffer, containing the most recent ExecuTorch log entries. */
   public String[] readLogBuffer() {
     return readLogBufferNative();

extension/android/jni/jni_layer.cpp

@@ -389,6 +389,16 @@ class ExecuTorchJni : public facebook::jni::HybridClass<ExecuTorchJni> {
 
   facebook::jni::local_ref<facebook::jni::JArrayClass<jstring>>
   readLogBuffer() {
+    return readLogBufferUtil();
+  }
+
+  static facebook::jni::local_ref<facebook::jni::JArrayClass<jstring>>
+  readLogBufferStatic(facebook::jni::alias_ref<jclass>) {
+    return readLogBufferUtil();
+  }
+
+  static facebook::jni::local_ref<facebook::jni::JArrayClass<jstring>>
+  readLogBufferUtil() {
 #ifdef __ANDROID__
 
     facebook::jni::local_ref<facebook::jni::JArrayClass<jstring>> ret;
@@ -500,6 +510,8 @@ class ExecuTorchJni : public facebook::jni::HybridClass<ExecuTorchJni> {
         makeNativeMethod("executeNative", ExecuTorchJni::execute),
         makeNativeMethod("loadMethodNative", ExecuTorchJni::load_method),
         makeNativeMethod("readLogBufferNative", ExecuTorchJni::readLogBuffer),
+        makeNativeMethod(
+            "readLogBufferStaticNative", ExecuTorchJni::readLogBufferStatic),
         makeNativeMethod("etdump", ExecuTorchJni::etdump),
         makeNativeMethod("getMethods", ExecuTorchJni::getMethods),
         makeNativeMethod("getUsedBackends", ExecuTorchJni::getUsedBackends),