Revert "[ORC] Tailor ELF debugger support plugin to load-address patching only" (llvm#169073)

Reverts llvm#168518

Author: weliveindetail

llvm/include/llvm/ExecutionEngine/Orc/Debugging/ELFDebugObjectPlugin.h

@@ -23,6 +23,7 @@
 #include "llvm/Support/MemoryBufferRef.h"
 #include "llvm/TargetParser/Triple.h"
 
+#include <functional>
 #include <map>
 #include <memory>
 #include <mutex>
@@ -32,32 +33,43 @@ namespace orc {
 
 class DebugObject;
 
-/// Debugger support for ELF platforms with the GDB JIT Interface. The plugin
-/// emits and manages a separate debug object allocation in addition to the
-/// LinkGraph's own allocation and it notifies the debugger when necessary.
+/// Creates and manages DebugObjects for JITLink artifacts.
+///
+/// DebugObjects are created when linking for a MaterializationResponsibility
+/// starts. They are pending as long as materialization is in progress.
+///
+/// There can only be one pending DebugObject per MaterializationResponsibility.
+/// If materialization fails, pending DebugObjects are discarded.
+///
+/// Once executable code for the MaterializationResponsibility is emitted, the
+/// corresponding DebugObject is finalized to target memory and the provided
+/// DebugObjectRegistrar is notified. Ownership of DebugObjects remains with the
+/// plugin.
 ///
 class LLVM_ABI ELFDebugObjectPlugin : public ObjectLinkingLayer::Plugin {
 public:
-  /// Create the plugin for the given session and set additional options
+  /// Create the plugin to submit DebugObjects for JITLink artifacts. For all
+  /// options the recommended setting is true.
   ///
   /// RequireDebugSections:
-  ///   Emit debug objects only if the LinkGraph contains debug info. Turning
-  ///   this off allows minimal debugging based on raw symbol names, but it
-  ///   comes with significant overhead for release configurations.
+  ///   Submit debug objects to the executor only if they contain actual debug
+  ///   info. Turning this off may allow minimal debugging based on raw symbol
+  ///   names. Note that this may cause significant memory and transport
+  ///   overhead for objects built with a release configuration.
   ///
   /// AutoRegisterCode:
   ///   Notify the debugger for each new debug object. This is a good default
   ///   mode, but it may cause significant overhead when adding many modules in
-  ///   sequence. Otherwise the user must call __jit_debug_register_code() in
-  ///   the debug session manually.
+  ///   sequence. When turning this off, the user has to issue the call to
+  ///   __jit_debug_register_code() on the executor side manually.
   ///
   ELFDebugObjectPlugin(ExecutionSession &ES, bool RequireDebugSections,
                        bool AutoRegisterCode, Error &Err);
   ~ELFDebugObjectPlugin() override;
 
   void notifyMaterializing(MaterializationResponsibility &MR,
                            jitlink::LinkGraph &G, jitlink::JITLinkContext &Ctx,
-                           MemoryBufferRef InputObj) override;
+                           MemoryBufferRef InputObject) override;
 
   Error notifyFailed(MaterializationResponsibility &MR) override;
   Error notifyRemovingResources(JITDylib &JD, ResourceKey K) override;
@@ -82,8 +94,6 @@ class LLVM_ABI ELFDebugObjectPlugin : public ObjectLinkingLayer::Plugin {
   ExecutorAddr RegistrationAction;
   bool RequireDebugSections;
   bool AutoRegisterCode;
-
-  DebugObject *getPendingDebugObj(MaterializationResponsibility &MR);
 };
 
 } // namespace orc