1 files changed, 138 insertions, 0 deletions
diff --git a/lib/ExecutionEngine/JITLink/MachOAtomGraphBuilder.h b/lib/ExecutionEngine/JITLink/MachOAtomGraphBuilder.h
new file mode 100644
index 000000000000..72d441b24d06
--- /dev/null
+++ b/lib/ExecutionEngine/JITLink/MachOAtomGraphBuilder.h
@@ -0,0 +1,138 @@
+//===----- MachOAtomGraphBuilder.h - MachO AtomGraph builder ----*- C++ -*-===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+//
+// Generic MachO AtomGraph building code.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LIB_EXECUTIONENGINE_JITLINK_MACHOATOMGRAPHBUILDER_H
+#define LIB_EXECUTIONENGINE_JITLINK_MACHOATOMGRAPHBUILDER_H
+
+#include "llvm/ExecutionEngine/JITLink/JITLink.h"
+
+#include "JITLinkGeneric.h"
+
+#include "llvm/Object/MachO.h"
+
+namespace llvm {
+namespace jitlink {
+
+class MachOAtomGraphBuilder {
+public:
+  virtual ~MachOAtomGraphBuilder();
+  Expected<std::unique_ptr<AtomGraph>> buildGraph();
+
+protected:
+  using OffsetToAtomMap = std::map<JITTargetAddress, DefinedAtom *>;
+
+  class MachOSection {
+  public:
+    MachOSection() = default;
+
+    /// Create a MachO section with the given address and alignment.
+    MachOSection(Section &GenericSection, JITTargetAddress Address,
+                 unsigned Alignment)
+        : Address(Address), GenericSection(&GenericSection),
+          Alignment(Alignment) {}
+
+    /// Create a section without address, content or size (used for common
+    /// symbol sections).
+    MachOSection(Section &GenericSection) : GenericSection(&GenericSection) {}
+
+    Section &getGenericSection() const {
+      assert(GenericSection && "Section is null");
+      return *GenericSection;
+    }
+
+    StringRef getName() const {
+      assert(GenericSection && "No generic section attached");
+      return GenericSection->getName();
+    }
+
+    MachOSection &setContent(StringRef Content) {
+      assert(!ContentPtr && !Size && "Content/zeroFill already set");
+      ContentPtr = Content.data();
+      Size = Content.size();
+      return *this;
+    }
+
+    MachOSection &setZeroFill(uint64_t Size) {
+      assert(!ContentPtr && !this->Size && "Content/zeroFill already set");
+      this->Size = Size;
+      return *this;
+    }
+
+    bool isZeroFill() const { return !ContentPtr; }
+
+    bool empty() const { return getSize() == 0; }
+
+    size_t getSize() const { return Size; }
+
+    StringRef getContent() const {
+      assert(ContentPtr && "getContent() called on zero-fill section");
+      return {ContentPtr, static_cast<size_t>(Size)};
+    }
+
+    JITTargetAddress getAddress() const { return Address; }
+
+    unsigned getAlignment() const { return Alignment; }
+
+    MachOSection &setNoDeadStrip(bool NoDeadStrip) {
+      this->NoDeadStrip = NoDeadStrip;
+      return *this;
+    }
+
+    bool isNoDeadStrip() const { return NoDeadStrip; }
+
+  private:
+    JITTargetAddress Address = 0;
+    Section *GenericSection = nullptr;
+    const char *ContentPtr = nullptr;
+    uint64_t Size = 0;
+    unsigned Alignment = 0;
+    bool NoDeadStrip = false;
+  };
+
+  using CustomAtomizeFunction = std::function<Error(MachOSection &S)>;
+
+  MachOAtomGraphBuilder(const object::MachOObjectFile &Obj);
+
+  AtomGraph &getGraph() const { return *G; }
+
+  const object::MachOObjectFile &getObject() const { return Obj; }
+
+  void addCustomAtomizer(StringRef SectionName, CustomAtomizeFunction Atomizer);
+
+  virtual Error addRelocations() = 0;
+
+  /// Returns true if Atom A and Atom B are at a fixed offset from one another
+  /// (i.e. if they're part of the same alt-entry chain).
+  bool areLayoutLocked(const Atom &A, const Atom &B);
+
+private:
+  static unsigned getPointerSize(const object::MachOObjectFile &Obj);
+  static support::endianness getEndianness(const object::MachOObjectFile &Obj);
+
+  MachOSection &getCommonSection();
+
+  Error parseSections();
+  Error addNonCustomAtoms();
+  Error addAtoms();
+
+  const object::MachOObjectFile &Obj;
+  std::unique_ptr<AtomGraph> G;
+  DenseMap<const DefinedAtom *, const DefinedAtom *> AltEntryStarts;
+  DenseMap<unsigned, MachOSection> Sections;
+  StringMap<CustomAtomizeFunction> CustomAtomizeFunctions;
+  Optional<MachOSection> CommonSymbolsSection;
+};
+
+} // end namespace jitlink
+} // end namespace llvm
+
+#endif // LIB_EXECUTIONENGINE_JITLINK_MACHOATOMGRAPHBUILDER_H