[lldb] Copy log files into diagnostic directory

This patch copies over log files to the diagnostic directory. The caveat
here is that this only works for logs that are redirected to a file. The
implementation piggybacks of the mapping kept by the debugger. The
advantage is that it's free until you generate the diagnostics, at which
point you only pay the price of copying over the file.

Differential revision: https://reviews.llvm.org/D135631

lldb/include/lldb/Core/Debugger.h

@@ -28,6 +28,7 @@
 #include "lldb/Target/TargetList.h"
 #include "lldb/Utility/Broadcaster.h"
 #include "lldb/Utility/ConstString.h"
+#include "lldb/Utility/Diagnostics.h"
 #include "lldb/Utility/FileSpec.h"
 #include "lldb/Utility/Status.h"
 #include "lldb/Utility/UserID.h"
@@ -596,6 +597,7 @@ class Debugger : public std::enable_shared_from_this<Debugger>,
   lldb::ListenerSP m_forward_listener_sp;
   llvm::once_flag m_clear_once;
   lldb::TargetSP m_dummy_target_sp;
+  Diagnostics::CallbackID m_diagnostics_callback_id;
 
   lldb_private::DebuggerDestroyCallback m_destroy_callback = nullptr;
   void *m_destroy_callback_baton = nullptr;

lldb/source/Core/Debugger.cpp

@@ -44,7 +44,6 @@
 #include "lldb/Target/Thread.h"
 #include "lldb/Target/ThreadList.h"
 #include "lldb/Utility/AnsiTerminal.h"
-#include "lldb/Utility/Diagnostics.h"
 #include "lldb/Utility/Event.h"
 #include "lldb/Utility/LLDBLog.h"
 #include "lldb/Utility/Listener.h"
@@ -842,6 +841,22 @@ Debugger::Debugger(lldb::LogOutputCallback log_callback, void *baton)
   if (!GetOutputFile().GetIsTerminalWithColors())
     SetUseColor(false);
 
+  if (Diagnostics::Enabled()) {
+    m_diagnostics_callback_id = Diagnostics::Instance().AddCallback(
+        [this](const FileSpec &dir) -> llvm::Error {
+          for (auto &entry : m_stream_handlers) {
+            llvm::StringRef log_path = entry.first();
+            llvm::StringRef file_name = llvm::sys::path::filename(log_path);
+            FileSpec destination = dir.CopyByAppendingPathComponent(file_name);
+            std::error_code ec =
+                llvm::sys::fs::copy_file(log_path, destination.GetPath());
+            if (ec)
+              return llvm::errorCodeToError(ec);
+          }
+          return llvm::Error::success();
+        });
+  }
+
 #if defined(_WIN32) && defined(ENABLE_VIRTUAL_TERMINAL_PROCESSING)
   // Enabling use of ANSI color codes because LLDB is using them to highlight
   // text.
@@ -880,6 +895,9 @@ void Debugger::Clear() {
     GetInputFile().Close();
 
     m_command_interpreter_up->Clear();
+
+    if (Diagnostics::Enabled())
+      Diagnostics::Instance().RemoveCallback(m_diagnostics_callback_id);
   });
 }
 

lldb/test/Shell/Diagnostics/Inputs/TestCopyLogs.in

@@ -0,0 +1 @@
+command alias logcommands log enable lldb commands

lldb/test/Shell/Diagnostics/TestCopyLogs.test

@@ -0,0 +1,7 @@
+# RUN: rm -rf %t
+# RUN: mkdir -p %t
+
+# RUN: %lldb -s %S/Inputs/TestCopyLogs.in -o 'logcommands -f %t/commands.log' -o 'diagnostics dump -d %t/diags'
+
+# RUN: cat %t/diags/commands.log | FileCheck %s
+# CHECK: Processing command: diagnostics dump