From ade71641dcf6fc2c457e318634f0bcff8f8feee1 Mon Sep 17 00:00:00 2001
From: Lang Hames <lhames@gmail.com>
Date: Tue, 18 Jan 2022 15:58:45 +1100
Subject: [PATCH] [ORC] Add Platform::teardownJITDylib method.

This is a counterpart to Platform::setupJITDylib, and is called when JITDylib
instances are removed (via ExecutionSession::removeJITDylib).

Upcoming MachOPlatform patches will use this to clear per-JITDylib data when
JITDylibs are removed.
---
 llvm/include/llvm/ExecutionEngine/Orc/Core.h           | 4 ++++
 llvm/include/llvm/ExecutionEngine/Orc/ELFNixPlatform.h | 1 +
 llvm/include/llvm/ExecutionEngine/Orc/MachOPlatform.h  | 1 +
 llvm/lib/ExecutionEngine/Orc/Core.cpp                  | 7 ++++++-
 llvm/lib/ExecutionEngine/Orc/ELFNixPlatform.cpp        | 4 ++++
 llvm/lib/ExecutionEngine/Orc/LLJIT.cpp                 | 5 +++++
 llvm/lib/ExecutionEngine/Orc/MachOPlatform.cpp         | 2 ++
 7 files changed, 23 insertions(+), 1 deletion(-)

diff --git a/llvm/include/llvm/ExecutionEngine/Orc/Core.h b/llvm/include/llvm/ExecutionEngine/Orc/Core.h
index b0931db..6bf5ba8 100644
--- a/llvm/include/llvm/ExecutionEngine/Orc/Core.h
+++ b/llvm/include/llvm/ExecutionEngine/Orc/Core.h
@@ -1309,6 +1309,10 @@ public:
   /// __dso_handle).
   virtual Error setupJITDylib(JITDylib &JD) = 0;
 
+  /// This method will be called outside the session lock each time a JITDylib
+  /// is removed to allow the Platform to remove any JITDylib-specific data.
+  virtual Error teardownJITDylib(JITDylib &JD) = 0;
+
   /// This method will be called under the ExecutionSession lock each time a
   /// MaterializationUnit is added to a JITDylib.
   virtual Error notifyAdding(ResourceTracker &RT,
diff --git a/llvm/include/llvm/ExecutionEngine/Orc/ELFNixPlatform.h b/llvm/include/llvm/ExecutionEngine/Orc/ELFNixPlatform.h
index 8f1bf85..6b12fe9 100644
--- a/llvm/include/llvm/ExecutionEngine/Orc/ELFNixPlatform.h
+++ b/llvm/include/llvm/ExecutionEngine/Orc/ELFNixPlatform.h
@@ -101,6 +101,7 @@ public:
   ObjectLinkingLayer &getObjectLinkingLayer() const { return ObjLinkingLayer; }
 
   Error setupJITDylib(JITDylib &JD) override;
+  Error teardownJITDylib(JITDylib &JD) override;
   Error notifyAdding(ResourceTracker &RT,
                      const MaterializationUnit &MU) override;
   Error notifyRemoving(ResourceTracker &RT) override;
diff --git a/llvm/include/llvm/ExecutionEngine/Orc/MachOPlatform.h b/llvm/include/llvm/ExecutionEngine/Orc/MachOPlatform.h
index 9482f20..01f3f1b 100644
--- a/llvm/include/llvm/ExecutionEngine/Orc/MachOPlatform.h
+++ b/llvm/include/llvm/ExecutionEngine/Orc/MachOPlatform.h
@@ -97,6 +97,7 @@ public:
   ObjectLinkingLayer &getObjectLinkingLayer() const { return ObjLinkingLayer; }
 
   Error setupJITDylib(JITDylib &JD) override;
+  Error teardownJITDylib(JITDylib &JD) override;
   Error notifyAdding(ResourceTracker &RT,
                      const MaterializationUnit &MU) override;
   Error notifyRemoving(ResourceTracker &RT) override;
diff --git a/llvm/lib/ExecutionEngine/Orc/Core.cpp b/llvm/lib/ExecutionEngine/Orc/Core.cpp
index 01921c2..c6933cf 100644
--- a/llvm/lib/ExecutionEngine/Orc/Core.cpp
+++ b/llvm/lib/ExecutionEngine/Orc/Core.cpp
@@ -1933,9 +1933,14 @@ Error ExecutionSession::removeJITDylib(JITDylib &JD) {
     JDs.erase(I);
   });
 
-  // Clear the JITDylib.
+  // Clear the JITDylib. Hold on to any error while we clean up the
+  // JITDylib members below.
   auto Err = JD.clear();
 
+  // Notify the platform of the teardown.
+  if (P)
+    Err = joinErrors(std::move(Err), P->teardownJITDylib(JD));
+
   // Set JD to closed state. Clear remaining data structures.
   runSessionLocked([&] {
     assert(JD.State == JITDylib::Closing && "JD should be closing");
diff --git a/llvm/lib/ExecutionEngine/Orc/ELFNixPlatform.cpp b/llvm/lib/ExecutionEngine/Orc/ELFNixPlatform.cpp
index e25d7c4..2552955 100644
--- a/llvm/lib/ExecutionEngine/Orc/ELFNixPlatform.cpp
+++ b/llvm/lib/ExecutionEngine/Orc/ELFNixPlatform.cpp
@@ -155,6 +155,10 @@ Error ELFNixPlatform::setupJITDylib(JITDylib &JD) {
       std::make_unique<DSOHandleMaterializationUnit>(*this, DSOHandleSymbol));
 }
 
+Error ELFNixPlatform::teardownJITDylib(JITDylib &JD) {
+  return Error::success();
+}
+
 Error ELFNixPlatform::notifyAdding(ResourceTracker &RT,
                                    const MaterializationUnit &MU) {
   auto &JD = RT.getJITDylib();
diff --git a/llvm/lib/ExecutionEngine/Orc/LLJIT.cpp b/llvm/lib/ExecutionEngine/Orc/LLJIT.cpp
index 0ab0d7d..cffc340 100644
--- a/llvm/lib/ExecutionEngine/Orc/LLJIT.cpp
+++ b/llvm/lib/ExecutionEngine/Orc/LLJIT.cpp
@@ -89,6 +89,7 @@ class GenericLLVMIRPlatform : public Platform {
 public:
   GenericLLVMIRPlatform(GenericLLVMIRPlatformSupport &S) : S(S) {}
   Error setupJITDylib(JITDylib &JD) override;
+  Error teardownJITDylib(JITDylib &JD) override;
   Error notifyAdding(ResourceTracker &RT,
                      const MaterializationUnit &MU) override;
   Error notifyRemoving(ResourceTracker &RT) override {
@@ -460,6 +461,10 @@ Error GenericLLVMIRPlatform::setupJITDylib(JITDylib &JD) {
   return S.setupJITDylib(JD);
 }
 
+Error GenericLLVMIRPlatform::teardownJITDylib(JITDylib &JD) {
+  return Error::success();
+}
+
 Error GenericLLVMIRPlatform::notifyAdding(ResourceTracker &RT,
                                           const MaterializationUnit &MU) {
   return S.notifyAdding(RT, MU);
diff --git a/llvm/lib/ExecutionEngine/Orc/MachOPlatform.cpp b/llvm/lib/ExecutionEngine/Orc/MachOPlatform.cpp
index c2a8965..9df4c8c 100644
--- a/llvm/lib/ExecutionEngine/Orc/MachOPlatform.cpp
+++ b/llvm/lib/ExecutionEngine/Orc/MachOPlatform.cpp
@@ -203,6 +203,8 @@ Error MachOPlatform::setupJITDylib(JITDylib &JD) {
       *this, MachOHeaderStartSymbol));
 }
 
+Error MachOPlatform::teardownJITDylib(JITDylib &JD) { return Error::success(); }
+
 Error MachOPlatform::notifyAdding(ResourceTracker &RT,
                                   const MaterializationUnit &MU) {
   auto &JD = RT.getJITDylib();
-- 
2.7.4