From 977abb05bc8e28edd0c233a318b865b380dd4101 Mon Sep 17 00:00:00 2001
From: Github Executorch <github_executorch@arm.com>
Date: Wed, 3 Sep 2025 18:30:28 -0700
Subject: [PATCH] Summary: Add detailed error message to exception flow

This should enhance the triaging and debuggability of Android ET related
issues

Test Plan: Build & CI

Reviewers:

Subscribers:

Tasks:

Tags:
---
 .../ExecutorchRuntimeException.java           | 50 +++++++++++++++----
 1 file changed, 41 insertions(+), 9 deletions(-)

diff --git a/extension/android/executorch_android/src/main/java/org/pytorch/executorch/ExecutorchRuntimeException.java b/extension/android/executorch_android/src/main/java/org/pytorch/executorch/ExecutorchRuntimeException.java
index de823f40afb..e180efcdfca 100644
--- a/extension/android/executorch_android/src/main/java/org/pytorch/executorch/ExecutorchRuntimeException.java
+++ b/extension/android/executorch_android/src/main/java/org/pytorch/executorch/ExecutorchRuntimeException.java
@@ -75,17 +75,49 @@ public class ExecutorchRuntimeException extends RuntimeException {
   }
 
   static class ErrorHelper {
+    // Reusable StringBuilder instance
+    private static final StringBuilder sb = new StringBuilder();
+
     static String formatMessage(int errorCode, String details) {
-      String baseMessage = ERROR_CODE_MESSAGES.get(errorCode);
-      if (baseMessage == null) {
-        baseMessage = "Unknown error code 0x" + Integer.toHexString(errorCode);
+      synchronized (sb) {
+        sb.setLength(0); // Clear the StringBuilder before use
+
+        String baseMessage = ERROR_CODE_MESSAGES.get(errorCode);
+        if (baseMessage == null) {
+          baseMessage = "Unknown error code 0x" + Integer.toHexString(errorCode);
+        }
+
+        sb.append("[Executorch Error 0x")
+            .append(Integer.toHexString(errorCode))
+            .append("] ")
+            .append(baseMessage)
+            .append(": ")
+            .append(details)
+            .append("\nDetailed Logs:\n");
+
+        try {
+          String[] logEntries = readLogBuffer(); // JNI call
+          formatLogEntries(sb, logEntries);
+        } catch (Exception e) {
+          sb.append("Failed to retrieve detailed logs: ").append(e.getMessage());
+        }
+
+        return sb.toString();
+      }
+    }
+
+    // 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) {
+        sb.append("No detailed logs available.");
+        return;
+      }
+      for (String entry : logEntries) {
+        sb.append(entry).append("\n");
       }
-      return "[Executorch Error 0x"
-          + Integer.toHexString(errorCode)
-          + "] "
-          + baseMessage
-          + ": "
-          + details;
     }
   }