1 files changed, 243 insertions, 0 deletions
diff --git a/llvm/lib/Object/MachOUniversal.cpp b/llvm/lib/Object/MachOUniversal.cpp
new file mode 100644
index 0000000000000..a178ecde949e5
--- /dev/null
+++ b/llvm/lib/Object/MachOUniversal.cpp
@@ -0,0 +1,243 @@
+//===- MachOUniversal.cpp - Mach-O universal binary -------------*- 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
+//
+//===----------------------------------------------------------------------===//
+//
+// This file defines the MachOUniversalBinary class.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Object/MachOUniversal.h"
+#include "llvm/Object/Archive.h"
+#include "llvm/Object/MachO.h"
+#include "llvm/Object/ObjectFile.h"
+#include "llvm/Support/Casting.h"
+#include "llvm/Support/Host.h"
+#include "llvm/Support/MemoryBuffer.h"
+
+using namespace llvm;
+using namespace object;
+
+static Error
+malformedError(Twine Msg) {
+  std::string StringMsg = "truncated or malformed fat file (" + Msg.str() + ")";
+  return make_error<GenericBinaryError>(std::move(StringMsg),
+                                        object_error::parse_failed);
+}
+
+template<typename T>
+static T getUniversalBinaryStruct(const char *Ptr) {
+  T Res;
+  memcpy(&Res, Ptr, sizeof(T));
+  // Universal binary headers have big-endian byte order.
+  if (sys::IsLittleEndianHost)
+    swapStruct(Res);
+  return Res;
+}
+
+MachOUniversalBinary::ObjectForArch::ObjectForArch(
+    const MachOUniversalBinary *Parent, uint32_t Index)
+    : Parent(Parent), Index(Index) {
+  // The iterators use Parent as a nullptr and an Index+1 == NumberOfObjects.
+  if (!Parent || Index >= Parent->getNumberOfObjects()) {
+    clear();
+  } else {
+    // Parse object header.
+    StringRef ParentData = Parent->getData();
+    if (Parent->getMagic() == MachO::FAT_MAGIC) {
+      const char *HeaderPos = ParentData.begin() + sizeof(MachO::fat_header) +
+                              Index * sizeof(MachO::fat_arch);
+      Header = getUniversalBinaryStruct<MachO::fat_arch>(HeaderPos);
+    } else { // Parent->getMagic() == MachO::FAT_MAGIC_64
+      const char *HeaderPos = ParentData.begin() + sizeof(MachO::fat_header) +
+                              Index * sizeof(MachO::fat_arch_64);
+      Header64 = getUniversalBinaryStruct<MachO::fat_arch_64>(HeaderPos);
+    }
+  }
+}
+
+Expected<std::unique_ptr<MachOObjectFile>>
+MachOUniversalBinary::ObjectForArch::getAsObjectFile() const {
+  if (!Parent)
+    report_fatal_error("MachOUniversalBinary::ObjectForArch::getAsObjectFile() "
+                       "called when Parent is a nullptr");
+
+  StringRef ParentData = Parent->getData();
+  StringRef ObjectData;
+  uint32_t cputype;
+  if (Parent->getMagic() == MachO::FAT_MAGIC) {
+    ObjectData = ParentData.substr(Header.offset, Header.size);
+    cputype = Header.cputype;
+  } else { // Parent->getMagic() == MachO::FAT_MAGIC_64
+    ObjectData = ParentData.substr(Header64.offset, Header64.size);
+    cputype = Header64.cputype;
+  }
+  StringRef ObjectName = Parent->getFileName();
+  MemoryBufferRef ObjBuffer(ObjectData, ObjectName);
+  return ObjectFile::createMachOObjectFile(ObjBuffer, cputype, Index);
+}
+
+Expected<std::unique_ptr<Archive>>
+MachOUniversalBinary::ObjectForArch::getAsArchive() const {
+  if (!Parent)
+    report_fatal_error("MachOUniversalBinary::ObjectForArch::getAsArchive() "
+                       "called when Parent is a nullptr");
+
+  StringRef ParentData = Parent->getData();
+  StringRef ObjectData;
+  if (Parent->getMagic() == MachO::FAT_MAGIC)
+    ObjectData = ParentData.substr(Header.offset, Header.size);
+  else // Parent->getMagic() == MachO::FAT_MAGIC_64
+    ObjectData = ParentData.substr(Header64.offset, Header64.size);
+  StringRef ObjectName = Parent->getFileName();
+  MemoryBufferRef ObjBuffer(ObjectData, ObjectName);
+  return Archive::create(ObjBuffer);
+}
+
+void MachOUniversalBinary::anchor() { }
+
+Expected<std::unique_ptr<MachOUniversalBinary>>
+MachOUniversalBinary::create(MemoryBufferRef Source) {
+  Error Err = Error::success();
+  std::unique_ptr<MachOUniversalBinary> Ret(
+      new MachOUniversalBinary(Source, Err));
+  if (Err)
+    return std::move(Err);
+  return std::move(Ret);
+}
+
+MachOUniversalBinary::MachOUniversalBinary(MemoryBufferRef Source, Error &Err)
+    : Binary(Binary::ID_MachOUniversalBinary, Source), Magic(0),
+      NumberOfObjects(0) {
+  ErrorAsOutParameter ErrAsOutParam(&Err);
+  if (Data.getBufferSize() < sizeof(MachO::fat_header)) {
+    Err = make_error<GenericBinaryError>("File too small to be a Mach-O "
+                                         "universal file",
+                                         object_error::invalid_file_type);
+    return;
+  }
+  // Check for magic value and sufficient header size.
+  StringRef Buf = getData();
+  MachO::fat_header H =
+      getUniversalBinaryStruct<MachO::fat_header>(Buf.begin());
+  Magic = H.magic;
+  NumberOfObjects = H.nfat_arch;
+  if (NumberOfObjects == 0) {
+    Err = malformedError("contains zero architecture types");
+    return;
+  }
+  uint32_t MinSize = sizeof(MachO::fat_header);
+  if (Magic == MachO::FAT_MAGIC)
+    MinSize += sizeof(MachO::fat_arch) * NumberOfObjects;
+  else if (Magic == MachO::FAT_MAGIC_64)
+    MinSize += sizeof(MachO::fat_arch_64) * NumberOfObjects;
+  else {
+    Err = malformedError("bad magic number");
+    return;
+  }
+  if (Buf.size() < MinSize) {
+    Err = malformedError("fat_arch" +
+                         Twine(Magic == MachO::FAT_MAGIC ? "" : "_64") +
+                         " structs would extend past the end of the file");
+    return;
+  }
+  for (uint32_t i = 0; i < NumberOfObjects; i++) {
+    ObjectForArch A(this, i);
+    uint64_t bigSize = A.getOffset();
+    bigSize += A.getSize();
+    if (bigSize > Buf.size()) {
+      Err = malformedError("offset plus size of cputype (" +
+        Twine(A.getCPUType()) + ") cpusubtype (" +
+        Twine(A.getCPUSubType() & ~MachO::CPU_SUBTYPE_MASK) +
+        ") extends past the end of the file");
+      return;
+    }
+
+    if (A.getAlign() > MaxSectionAlignment) {
+      Err = malformedError("align (2^" + Twine(A.getAlign()) +
+                           ") too large for cputype (" + Twine(A.getCPUType()) +
+                           ") cpusubtype (" +
+                           Twine(A.getCPUSubType() & ~MachO::CPU_SUBTYPE_MASK) +
+                           ") (maximum 2^" + Twine(MaxSectionAlignment) + ")");
+      return;
+    }
+    if(A.getOffset() % (1ull << A.getAlign()) != 0){
+      Err = malformedError("offset: " + Twine(A.getOffset()) +
+        " for cputype (" + Twine(A.getCPUType()) + ") cpusubtype (" +
+        Twine(A.getCPUSubType() & ~MachO::CPU_SUBTYPE_MASK) +
+        ") not aligned on it's alignment (2^" + Twine(A.getAlign()) + ")");
+      return;
+    }
+    if (A.getOffset() < MinSize) {
+      Err =  malformedError("cputype (" + Twine(A.getCPUType()) + ") "
+        "cpusubtype (" + Twine(A.getCPUSubType() & ~MachO::CPU_SUBTYPE_MASK) +
+        ") offset " + Twine(A.getOffset()) + " overlaps universal headers");
+      return;
+    }
+  }
+  for (uint32_t i = 0; i < NumberOfObjects; i++) {
+    ObjectForArch A(this, i);
+    for (uint32_t j = i + 1; j < NumberOfObjects; j++) {
+      ObjectForArch B(this, j);
+      if (A.getCPUType() == B.getCPUType() &&
+          (A.getCPUSubType() & ~MachO::CPU_SUBTYPE_MASK) ==
+          (B.getCPUSubType() & ~MachO::CPU_SUBTYPE_MASK)) {
+        Err = malformedError("contains two of the same architecture (cputype "
+          "(" + Twine(A.getCPUType()) + ") cpusubtype (" +
+          Twine(A.getCPUSubType() & ~MachO::CPU_SUBTYPE_MASK) + "))");
+        return;
+      }
+      if ((A.getOffset() >= B.getOffset() &&
+           A.getOffset() < B.getOffset() + B.getSize()) ||
+          (A.getOffset() + A.getSize() > B.getOffset() &&
+           A.getOffset() + A.getSize() < B.getOffset() + B.getSize()) ||
+          (A.getOffset() <= B.getOffset() &&
+           A.getOffset() + A.getSize() >= B.getOffset() + B.getSize())) {
+        Err =  malformedError("cputype (" + Twine(A.getCPUType()) + ") "
+          "cpusubtype (" + Twine(A.getCPUSubType() & ~MachO::CPU_SUBTYPE_MASK) +
+          ") at offset " + Twine(A.getOffset()) + " with a size of " +
+          Twine(A.getSize()) + ", overlaps cputype (" + Twine(B.getCPUType()) +
+          ") cpusubtype (" + Twine(B.getCPUSubType() & ~MachO::CPU_SUBTYPE_MASK)
+          + ") at offset " + Twine(B.getOffset()) + " with a size of "
+          + Twine(B.getSize()));
+        return;
+      }
+    }
+  }
+  Err = Error::success();
+}
+
+Expected<MachOUniversalBinary::ObjectForArch>
+MachOUniversalBinary::getObjectForArch(StringRef ArchName) const {
+  if (Triple(ArchName).getArch() == Triple::ArchType::UnknownArch)
+    return make_error<GenericBinaryError>("Unknown architecture "
+                                          "named: " +
+                                              ArchName,
+                                          object_error::arch_not_found);
+  for (const auto &Obj : objects())
+    if (Obj.getArchFlagName() == ArchName)
+      return Obj;
+  return make_error<GenericBinaryError>("fat file does not "
+                                        "contain " +
+                                            ArchName,
+                                        object_error::arch_not_found);
+}
+
+Expected<std::unique_ptr<MachOObjectFile>>
+MachOUniversalBinary::getMachOObjectForArch(StringRef ArchName) const {
+  Expected<ObjectForArch> O = getObjectForArch(ArchName);
+  if (!O)
+    return O.takeError();
+  return O->getAsObjectFile();
+}
+
+Expected<std::unique_ptr<Archive>>
+MachOUniversalBinary::getArchiveForArch(StringRef ArchName) const {
+  Expected<ObjectForArch> O = getObjectForArch(ArchName);
+  if (!O)
+    return O.takeError();
+  return O->getAsArchive();
+}