Add error_msg argument to CloseNativeLibrary

error_msg is set when dlclose/NativeBridgeUnloadLibrary fails.

Bug: https://issuetracker.google.com/79126103
Test: make
Change-Id: I043580209538ff47320e8d9a304a21c00c4b149f

2 files changed, 18 insertions, 5 deletions

diff --git a/libnativeloader/include/nativeloader/native_loader.h b/libnativeloader/include/nativeloader/native_loader.h
index 19a17832e..c1d9d2a92 100644
--- a/libnativeloader/include/nativeloader/native_loader.h
+++ b/libnativeloader/include/nativeloader/native_loader.h
@@ -47,8 +47,9 @@ void* OpenNativeLibrary(JNIEnv* env,
                         bool* needs_native_bridge,
                         std::string* error_msg);
 
-__attribute__((visibility("default")))
-bool CloseNativeLibrary(void* handle, const bool needs_native_bridge);
+__attribute__((visibility("default"))) bool CloseNativeLibrary(void* handle,
+                                                               const bool needs_native_bridge,
+                                                               std::string* error_msg);
 
 #if defined(__ANDROID__)
 // Look up linker namespace by class_loader. Returns nullptr if
diff --git a/libnativeloader/native_loader.cpp b/libnativeloader/native_loader.cpp
index 67c1c103b..b3e2b97fe 100644
--- a/libnativeloader/native_loader.cpp
+++ b/libnativeloader/native_loader.cpp
@@ -710,9 +710,21 @@ void* OpenNativeLibrary(JNIEnv* env,
 #endif
 }
 
-bool CloseNativeLibrary(void* handle, const bool needs_native_bridge) {
-    return needs_native_bridge ? NativeBridgeUnloadLibrary(handle) :
-                                 dlclose(handle);
+bool CloseNativeLibrary(void* handle, const bool needs_native_bridge, std::string* error_msg) {
+  bool success;
+  if (needs_native_bridge) {
+    success = (NativeBridgeUnloadLibrary(handle) == 0);
+    if (!success) {
+      *error_msg = NativeBridgeGetError();
+    }
+  } else {
+    success = (dlclose(handle) == 0);
+    if (!success) {
+      *error_msg = dlerror();
+    }
+  }
+
+  return success;
 }
 
 #if defined(__ANDROID__)