[C-API] LLVMOrcCreateObjectLinkingLayerWithInProcessMemoryManager

Allow C programs to use JITLink instead of RuntimeDyld.  Modeled on
LLVMOrcCreateRTDyldObjectLinkingLayerWithSectionMemoryManager except
that it has to deal with failure to create InProcessMemoryManager.  In
that case it returns nullptr.

Author: macdice

llvm/include/llvm-c/OrcEE.h

@@ -43,6 +43,15 @@ typedef void (*LLVMMemoryManagerNotifyTerminatingCallback)(void *CtxCtx);
  * @{
  */
 
+/**
+ * Create a ObjectLinkingLayer instance using the standard JITLink
+ * InProcessMemoryManager for memory management.  Result is NULL on failure to
+ * determine system page size.
+ */
+LLVMOrcObjectLayerRef
+LLVMOrcCreateObjectLinkingLayerWithInProcessMemoryManager(
+    LLVMOrcExecutionSessionRef ES);
+
 /**
  * Create a RTDyldObjectLinkingLayer instance using the standard
  * SectionMemoryManager for memory management.

llvm/lib/ExecutionEngine/Orc/OrcV2CBindings.cpp

@@ -11,9 +11,11 @@
 #include "llvm-c/OrcEE.h"
 #include "llvm-c/TargetMachine.h"
 
+#include "llvm/ExecutionEngine/JITLink/JITLinkMemoryManager.h"
 #include "llvm/ExecutionEngine/Orc/AbsoluteSymbols.h"
 #include "llvm/ExecutionEngine/Orc/JITTargetMachineBuilder.h"
 #include "llvm/ExecutionEngine/Orc/LLJIT.h"
+#include "llvm/ExecutionEngine/Orc/ObjectLinkingLayer.h"
 #include "llvm/ExecutionEngine/Orc/ObjectTransformLayer.h"
 #include "llvm/ExecutionEngine/Orc/RTDyldObjectLinkingLayer.h"
 #include "llvm/ExecutionEngine/SectionMemoryManager.h"
@@ -1017,6 +1019,18 @@ LLVMOrcLLJITGetObjTransformLayer(LLVMOrcLLJITRef J) {
   return wrap(&unwrap(J)->getObjTransformLayer());
 }
 
+LLVMOrcObjectLayerRef
+LLVMOrcCreateObjectLinkingLayerWithInProcessMemoryManager(
+    LLVMOrcExecutionSessionRef ES) {
+  assert(ES && "ES must not be null");
+  auto mm = jitlink::InProcessMemoryManager::Create();
+  if (!mm) {
+    unwrap(ES)->reportError(mm.takeError());
+    return nullptr;
+  }
+  return wrap(new ObjectLinkingLayer(*unwrap(ES), std::move(*mm)));
+}
+
 LLVMOrcObjectLayerRef
 LLVMOrcCreateRTDyldObjectLinkingLayerWithSectionMemoryManager(
     LLVMOrcExecutionSessionRef ES) {