commit 4fc68b9b7f3e07ea4425c6111e1a9455cf4aa322
author Lang Hames <lhames@gmail.com> Wed Dec 04 22:45:38 2019 -0800
committer Lang Hames <lhames@gmail.com> Thu Dec 05 01:36:49 2019 -0800
tree a34b36b9bd3fc33df70ba3f6fcef2f17785ce69c
parent 76a5c8421e04b246892157fe18f1c082c908c5e9

[ORC] Remove the automagic Main JITDylib fram ExecutionSession.

This patch removes the magic "main" JITDylib from ExecutionEngine. The main
JITDylib was created automatically at ExecutionSession construction time, and
all subsequently created JITDylibs were added to the main JITDylib's
links-against list by default. This saves a couple of lines of boilerplate for
simple JIT setups, but this isn't worth introducing magical behavior for.

ORCv2 clients should now construct their own main JITDylib using
ExecutionSession::createJITDylib and set up its linkages manually using
JITDylib::setSearchOrder (or related methods in JITDylib).

llvm/lib/ExecutionEngine/Orc/CompileOnDemandLayer.cpp

diff --git a/llvm/lib/ExecutionEngine/Orc/CompileOnDemandLayer.cpp b/llvm/lib/ExecutionEngine/Orc/CompileOnDemandLayer.cpp
index b8e4292..f26835f 100644
--- a/llvm/lib/ExecutionEngine/Orc/CompileOnDemandLayer.cpp
+++ b/llvm/lib/ExecutionEngine/Orc/CompileOnDemandLayer.cpp
@@ -172,8 +172,8 @@
 CompileOnDemandLayer::getPerDylibResources(JITDylib &TargetD) {
   auto I = DylibResources.find(&TargetD);
   if (I == DylibResources.end()) {
-    auto &ImplD = getExecutionSession().createJITDylib(
-        TargetD.getName() + ".impl", false);
+    auto &ImplD =
+        getExecutionSession().createJITDylib(TargetD.getName() + ".impl");
     TargetD.withSearchOrderDo(
         [&](const JITDylibSearchOrder &TargetSearchOrder) {
           auto NewSearchOrder = TargetSearchOrder;

llvm/lib/ExecutionEngine/Orc/Core.cpp

diff --git a/llvm/lib/ExecutionEngine/Orc/Core.cpp b/llvm/lib/ExecutionEngine/Orc/Core.cpp
index 0814ec1..63ef889 100644
--- a/llvm/lib/ExecutionEngine/Orc/Core.cpp
+++ b/llvm/lib/ExecutionEngine/Orc/Core.cpp
@@ -1854,12 +1854,6 @@
 
 ExecutionSession::ExecutionSession(std::shared_ptr<SymbolStringPool> SSP)
     : SSP(SSP ? std::move(SSP) : std::make_shared<SymbolStringPool>()) {
-  // Construct the main dylib.
-  JDs.push_back(std::unique_ptr<JITDylib>(new JITDylib(*this, "<main>")));
-}
-
-JITDylib &ExecutionSession::getMainJITDylib() {
-  return runSessionLocked([this]() -> JITDylib & { return *JDs.front(); });
 }
 
 JITDylib *ExecutionSession::getJITDylibByName(StringRef Name) {
@@ -1871,14 +1865,11 @@
   });
 }
 
-JITDylib &ExecutionSession::createJITDylib(std::string Name,
-                                           bool AddToMainDylibSearchOrder) {
+JITDylib &ExecutionSession::createJITDylib(std::string Name) {
   assert(!getJITDylibByName(Name) && "JITDylib with that name already exists");
   return runSessionLocked([&, this]() -> JITDylib & {
     JDs.push_back(
         std::unique_ptr<JITDylib>(new JITDylib(*this, std::move(Name))));
-    if (AddToMainDylibSearchOrder)
-      JDs.front()->addToSearchOrder(*JDs.back());
     return *JDs.back();
   });
 }

llvm/lib/ExecutionEngine/Orc/LLJIT.cpp

diff --git a/llvm/lib/ExecutionEngine/Orc/LLJIT.cpp b/llvm/lib/ExecutionEngine/Orc/LLJIT.cpp
index fb5515c..89dad6d 100644
--- a/llvm/lib/ExecutionEngine/Orc/LLJIT.cpp
+++ b/llvm/lib/ExecutionEngine/Orc/LLJIT.cpp
@@ -105,7 +105,7 @@
 
 LLJIT::LLJIT(LLJITBuilderState &S, Error &Err)
     : ES(S.ES ? std::move(S.ES) : std::make_unique<ExecutionSession>()),
-      Main(this->ES->getMainJITDylib()), DL(""),
+      Main(this->ES->createJITDylib("<main>")), DL(""),
       ObjLinkingLayer(createObjectLinkingLayer(S, *ES)),
       ObjTransformLayer(*this->ES, *ObjLinkingLayer), CtorRunner(Main),
       DtorRunner(Main) {