[Lldb-commits] [lldb] 26e9f23 - [lldb] Add the ability to remove diagnostic callbacks

[Jonas Devlieghere via lldb-commits]

Author: Jonas Devlieghere
Date: 2023-02-09T13:20:51-08:00
New Revision: 26e9f23ada4f7dea37199bca89ce628e2a54b74e

URL: https://github.com/llvm/llvm-project/commit/26e9f23ada4f7dea37199bca89ce628e2a54b74e
DIFF: https://github.com/llvm/llvm-project/commit/26e9f23ada4f7dea37199bca89ce628e2a54b74e.diff

LOG: [lldb] Add the ability to remove diagnostic callbacks

Add the ability to remove diagnostic callbacks. This is necessary for
diagnostics who's lifetime is tied to objects that can be destroyed.

Differential revision: https://reviews.llvm.org/D143548

Added: 
    

Modified: 
    lldb/include/lldb/Utility/Diagnostics.h
    lldb/source/Utility/Diagnostics.cpp

Removed: 
    


################################################################################
diff  --git a/lldb/include/lldb/Utility/Diagnostics.h b/lldb/include/lldb/Utility/Diagnostics.h
index 5d23fa8ae2348..c2e4b44350a37 100644
--- a/lldb/include/lldb/Utility/Diagnostics.h
+++ b/lldb/include/lldb/Utility/Diagnostics.h
@@ -42,8 +42,10 @@ class Diagnostics {
   void Report(llvm::StringRef message);
 
   using Callback = std::function<llvm::Error(const FileSpec &)>;
+  using CallbackID = uint64_t;
 
-  void AddCallback(Callback callback);
+  CallbackID AddCallback(Callback callback);
+  void RemoveCallback(CallbackID id);
 
   static Diagnostics &Instance();
 
@@ -61,7 +63,21 @@ class Diagnostics {
 
   RotatingLogHandler m_log_handler;
 
-  llvm::SmallVector<Callback, 4> m_callbacks;
+  struct CallbackEntry {
+    CallbackEntry(CallbackID id, Callback callback)
+        : id(id), callback(std::move(callback)) {}
+    CallbackID id;
+    Callback callback;
+  };
+
+  /// Monotonically increasing callback identifier. Unique per Diagnostic
+  /// instance.
+  CallbackID m_callback_id;
+
+  /// List of callback entries.
+  llvm::SmallVector<CallbackEntry, 4> m_callbacks;
+
+  /// Mutex to protect callback list and callback identifier.
   std::mutex m_callbacks_mutex;
 };
 

diff  --git a/lldb/source/Utility/Diagnostics.cpp b/lldb/source/Utility/Diagnostics.cpp
index a59750167cf74..1632ae0f9dfd3 100644
--- a/lldb/source/Utility/Diagnostics.cpp
+++ b/lldb/source/Utility/Diagnostics.cpp
@@ -43,9 +43,19 @@ Diagnostics::Diagnostics() : m_log_handler(g_num_log_messages) {}
 
 Diagnostics::~Diagnostics() {}
 
-void Diagnostics::AddCallback(Callback callback) {
+Diagnostics::CallbackID Diagnostics::AddCallback(Callback callback) {
   std::lock_guard<std::mutex> guard(m_callbacks_mutex);
-  m_callbacks.push_back(callback);
+  CallbackID id = m_callback_id++;
+  m_callbacks.emplace_back(id, callback);
+  return id;
+}
+
+void Diagnostics::RemoveCallback(CallbackID id) {
+  std::lock_guard<std::mutex> guard(m_callbacks_mutex);
+  m_callbacks.erase(
+      std::remove_if(m_callbacks.begin(), m_callbacks.end(),
+                     [id](const CallbackEntry &e) { return e.id == id; }),
+      m_callbacks.end());
 }
 
 bool Diagnostics::Dump(raw_ostream &stream) {
@@ -84,8 +94,8 @@ Error Diagnostics::Create(const FileSpec &dir) {
   if (Error err = DumpDiangosticsLog(dir))
     return err;
 
-  for (Callback c : m_callbacks) {
-    if (Error err = c(dir))
+  for (CallbackEntry e : m_callbacks) {
+    if (Error err = e.callback(dir))
       return err;
   }