1 files changed, 105 insertions, 0 deletions
diff --git a/llvm/lib/ExecutionEngine/Orc/LinkGraphLayer.cpp b/llvm/lib/ExecutionEngine/Orc/LinkGraphLayer.cpp
new file mode 100644
index 0000000..5789079
--- /dev/null
+++ b/llvm/lib/ExecutionEngine/Orc/LinkGraphLayer.cpp
@@ -0,0 +1,105 @@
+//===----- LinkGraphLayer.cpp - Add LinkGraphs to an ExecutionSession -----===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/ExecutionEngine/Orc/LinkGraphLayer.h"
+
+#include "llvm/ExecutionEngine/JITLink/JITLink.h"
+#include "llvm/ExecutionEngine/Orc/Shared/MachOObjectFormat.h"
+#include "llvm/ExecutionEngine/Orc/Shared/ObjectFormats.h"
+
+#define DEBUG_TYPE "orc"
+
+using namespace llvm;
+using namespace llvm::jitlink;
+using namespace llvm::orc;
+
+namespace {
+
+bool hasInitializerSection(LinkGraph &G) {
+  bool IsMachO = G.getTargetTriple().isOSBinFormatMachO();
+  bool IsElf = G.getTargetTriple().isOSBinFormatELF();
+  if (!IsMachO && !IsElf)
+    return false;
+
+  for (auto &Sec : G.sections()) {
+    if (IsMachO && isMachOInitializerSection(Sec.getName()))
+      return true;
+    if (IsElf && isELFInitializerSection(Sec.getName()))
+      return true;
+  }
+
+  return false;
+}
+
+} // end anonymous namespace
+
+namespace llvm::orc {
+
+LinkGraphLayer::~LinkGraphLayer() = default;
+
+MaterializationUnit::Interface LinkGraphLayer::getInterface(LinkGraph &G) {
+
+  MaterializationUnit::Interface LGI;
+
+  auto AddSymbol = [&](Symbol *Sym) {
+    // Skip local symbols.
+    if (Sym->getScope() == Scope::Local)
+      return;
+    assert(Sym->hasName() && "Anonymous non-local symbol?");
+
+    LGI.SymbolFlags[Sym->getName()] = getJITSymbolFlagsForSymbol(*Sym);
+  };
+
+  for (auto *Sym : G.defined_symbols())
+    AddSymbol(Sym);
+  for (auto *Sym : G.absolute_symbols())
+    AddSymbol(Sym);
+
+  if (hasInitializerSection(G)) {
+    std::string InitSymString;
+    {
+      raw_string_ostream(InitSymString)
+          << "$." << G.getName() << ".__inits" << Counter++;
+    }
+    LGI.InitSymbol = ES.intern(InitSymString);
+  }
+
+  return LGI;
+}
+
+JITSymbolFlags LinkGraphLayer::getJITSymbolFlagsForSymbol(Symbol &Sym) {
+  JITSymbolFlags Flags;
+
+  if (Sym.getLinkage() == Linkage::Weak)
+    Flags |= JITSymbolFlags::Weak;
+
+  if (Sym.getScope() == Scope::Default)
+    Flags |= JITSymbolFlags::Exported;
+  else if (Sym.getScope() == Scope::SideEffectsOnly)
+    Flags |= JITSymbolFlags::MaterializationSideEffectsOnly;
+
+  if (Sym.isCallable())
+    Flags |= JITSymbolFlags::Callable;
+
+  return Flags;
+}
+
+StringRef LinkGraphMaterializationUnit::getName() const { return G->getName(); }
+
+void LinkGraphMaterializationUnit::discard(const JITDylib &JD,
+                                           const SymbolStringPtr &Name) {
+  for (auto *Sym : G->defined_symbols())
+    if (Sym->getName() == Name) {
+      assert(Sym->getLinkage() == Linkage::Weak &&
+             "Discarding non-weak definition");
+      G->makeExternal(*Sym);
+      break;
+    }
+}
+
+} // namespace llvm::orc