[Clang-Repl] Add support for out-of-process execution. (#110418)

This PR introduces out-of-process (OOP) execution support for
Clang-Repl. With this enhancement, two new flags, `oop-executor` and
`oop-executor-connect`, are added to the Clang-Repl interface. These
flags enable the launch of an external executor
(`llvm-jitlink-executor`), which handles code execution in a separate
process.

1 files changed, 29 insertions, 8 deletions

diff --git a/clang/lib/Interpreter/Interpreter.cpp b/clang/lib/Interpreter/Interpreter.cpp
index bc96da8..8eacbc6 100644
--- a/clang/lib/Interpreter/Interpreter.cpp
+++ b/clang/lib/Interpreter/Interpreter.cpp
@@ -44,6 +44,7 @@
 #include "clang/Sema/Lookup.h"
 #include "clang/Serialization/ObjectFilePCHContainerReader.h"
 #include "llvm/ExecutionEngine/JITSymbol.h"
+#include "llvm/ExecutionEngine/Orc/EPCDynamicLibrarySearchGenerator.h"
 #include "llvm/ExecutionEngine/Orc/LLJIT.h"
 #include "llvm/IR/Module.h"
 #include "llvm/Support/Errc.h"
@@ -456,10 +457,11 @@ const char *const Runtimes = R"(
 )";
 
 llvm::Expected<std::unique_ptr<Interpreter>>
-Interpreter::create(std::unique_ptr<CompilerInstance> CI) {
+Interpreter::create(std::unique_ptr<CompilerInstance> CI,
+                    std::unique_ptr<llvm::orc::LLJITBuilder> JB) {
   llvm::Error Err = llvm::Error::success();
-  auto Interp =
-      std::unique_ptr<Interpreter>(new Interpreter(std::move(CI), Err));
+  auto Interp = std::unique_ptr<Interpreter>(
+      new Interpreter(std::move(CI), Err, JB ? std::move(JB) : nullptr));
   if (Err)
     return std::move(Err);
 
@@ -578,6 +580,25 @@ createJITTargetMachineBuilder(const std::string &TT) {
   return llvm::orc::JITTargetMachineBuilder(llvm::Triple(TT));
 }
 
+llvm::Expected<std::unique_ptr<llvm::orc::LLJITBuilder>>
+Interpreter::createLLJITBuilder(
+    std::unique_ptr<llvm::orc::ExecutorProcessControl> EPC,
+    llvm::StringRef OrcRuntimePath) {
+  const std::string &TT = EPC->getTargetTriple().getTriple();
+  auto JTMB = createJITTargetMachineBuilder(TT);
+  if (!JTMB)
+    return JTMB.takeError();
+  auto JB = IncrementalExecutor::createDefaultJITBuilder(std::move(*JTMB));
+  if (!JB)
+    return JB.takeError();
+
+  (*JB)->setExecutorProcessControl(std::move(EPC));
+  (*JB)->setPlatformSetUp(
+      llvm::orc::ExecutorNativePlatform(OrcRuntimePath.str()));
+
+  return std::move(*JB);
+}
+
 llvm::Error Interpreter::CreateExecutor() {
   if (IncrExecutor)
     return llvm::make_error<llvm::StringError>("Operation failed. "
@@ -702,11 +723,11 @@ llvm::Error Interpreter::LoadDynamicLibrary(const char *name) {
   if (!EE)
     return EE.takeError();
 
-  auto &DL = EE->getDataLayout();
-
-  if (auto DLSG = llvm::orc::DynamicLibrarySearchGenerator::Load(
-          name, DL.getGlobalPrefix()))
-    EE->getMainJITDylib().addGenerator(std::move(*DLSG));
+  if (auto DLSG = llvm::orc::EPCDynamicLibrarySearchGenerator::Load(
+          EE->getExecutionSession(), name))
+    // FIXME: Eventually we should put each library in its own JITDylib and
+    //        turn off process symbols by default.
+    EE->getProcessSymbolsJITDylib()->addGenerator(std::move(*DLSG));
   else
     return DLSG.takeError();