Refactor log channel registration mechanism

Summary:
We currently have two log channel registration mechanisms. One uses a
set of function pointers and the other one is based on the
PluginManager.

The PluginManager dependency is unfortunate, as logging
is also used in lldb-server, and the PluginManager pulls in a lot of
classes which are not used in lldb-server.

Both approach have the problem that they leave too much to do for the
user, and so the individual log channels end up reimplementing command
line argument parsing, category listing, etc.

Here, I replace the PluginManager-based approach with a one. The new API
is more declarative, so the user only needs to specify the list of list
of channels, their descriptions, etc., and all the common tasks like
enabling/disabling categories are hadled by common code. I migrate the
LogChannelDWARF (only user of the PluginManager method) to the new API.

In the follow-up commits I'll replace the other channels with something
similar.

Reviewers: clayborg, zturner, beanz

Subscribers: aprantl, lldb-commits

Differential Revision: https://reviews.llvm.org/D29895

llvm-svn: 295190

1 files changed, 10 insertions, 34 deletions

diff --git a/lldb/source/Commands/CommandObjectLog.cpp b/lldb/source/Commands/CommandObjectLog.cpp
index 6fbab08ac63..c10f868dea4 100644
--- a/lldb/source/Commands/CommandObjectLog.cpp
+++ b/lldb/source/Commands/CommandObjectLog.cpp
@@ -227,25 +227,15 @@ protected:
       return false;
     }
 
-    Log::Callbacks log_callbacks;
-
     const std::string channel = args[0].ref;
     args.Shift(); // Shift off the channel
-    if (Log::GetLogChannelCallbacks(ConstString(channel), log_callbacks)) {
-      log_callbacks.disable(args.GetConstArgumentVector(),
-                            &result.GetErrorStream());
-      result.SetStatus(eReturnStatusSuccessFinishNoResult);
-    } else if (channel == "all") {
+    if (channel == "all") {
       Log::DisableAllLogChannels(&result.GetErrorStream());
+      result.SetStatus(eReturnStatusSuccessFinishNoResult);
     } else {
-      LogChannelSP log_channel_sp(LogChannel::FindPlugin(channel.data()));
-      if (log_channel_sp) {
-        log_channel_sp->Disable(args.GetConstArgumentVector(),
-                                &result.GetErrorStream());
+      if (Log::DisableLogChannel(channel, args.GetConstArgumentVector(),
+                                 result.GetErrorStream()))
         result.SetStatus(eReturnStatusSuccessFinishNoResult);
-      } else
-        result.AppendErrorWithFormat("Invalid log channel '%s'.\n",
-                                     channel.data());
     }
     return result.Succeeded();
   }
@@ -284,26 +274,12 @@ protected:
       Log::ListAllLogChannels(&result.GetOutputStream());
       result.SetStatus(eReturnStatusSuccessFinishResult);
     } else {
-      for (auto &entry : args.entries()) {
-        Log::Callbacks log_callbacks;
-
-        if (Log::GetLogChannelCallbacks(ConstString(entry.ref),
-                                        log_callbacks)) {
-          log_callbacks.list_categories(&result.GetOutputStream());
-          result.SetStatus(eReturnStatusSuccessFinishResult);
-        } else if (entry.ref == "all") {
-          Log::ListAllLogChannels(&result.GetOutputStream());
-          result.SetStatus(eReturnStatusSuccessFinishResult);
-        } else {
-          LogChannelSP log_channel_sp(LogChannel::FindPlugin(entry.c_str()));
-          if (log_channel_sp) {
-            log_channel_sp->ListCategories(&result.GetOutputStream());
-            result.SetStatus(eReturnStatusSuccessFinishNoResult);
-          } else
-            result.AppendErrorWithFormat("Invalid log channel '%s'.\n",
-                                         entry.c_str());
-        }
-      }
+      bool success = true;
+      for (const auto &entry : args.entries())
+        success = success && Log::ListChannelCategories(
+                                 entry.ref, result.GetOutputStream());
+      if (success)
+        result.SetStatus(eReturnStatusSuccessFinishResult);
     }
     return result.Succeeded();
   }