macho-dump: Add support for dumping segment load commands.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@120203 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/Object/MachOFormat.h

@@ -146,6 +146,39 @@ namespace macho {
     uint32_t Size;
   };
 
+  /// @name Load Command Structures
+  /// @{
+
+  struct SegmentLoadCommand {
+    uint32_t Type;
+    uint32_t Size;
+    char Name[16];
+    uint32_t VMAddress;
+    uint32_t VMSize;
+    uint32_t FileOffset;
+    uint32_t FileSize;
+    uint32_t MaxVMProtection;
+    uint32_t InitialVMProtection;
+    uint32_t NumSections;
+    uint32_t Flags;
+  };
+
+  struct Segment64LoadCommand {
+    uint32_t Type;
+    uint32_t Size;
+    char Name[16];
+    uint64_t VMAddress;
+    uint64_t VMSize;
+    uint64_t FileOffset;
+    uint64_t FileSize;
+    uint32_t MaxVMProtection;
+    uint32_t InitialVMProtection;
+    uint32_t NumSections;
+    uint32_t Flags;
+  };
+
+  /// @}
+
   // See <mach-o/nlist.h>.
   enum SymbolTypeType {
     STT_Undefined = 0x00,

include/llvm/Object/MachOObject.h

@@ -11,6 +11,7 @@
 #define LLVM_OBJECT_MACHOOBJECT_H
 
 #include <string>
+#include "llvm/ADT/InMemoryStruct.h"
 #include "llvm/ADT/OwningPtr.h"
 #include "llvm/Object/MachOFormat.h"
 
@@ -88,6 +89,7 @@ public:
   /// @{
 
   bool isLittleEndian() const { return IsLittleEndian; }
+  bool isSwappedEndian() const { return IsSwappedEndian; }
   bool is64Bit() const { return Is64Bit; }
 
   unsigned getHeaderSize() const {
@@ -111,6 +113,13 @@ public:
   /// \brief Retrieve the information for the given load command.
   const LoadCommandInfo &getLoadCommandInfo(unsigned Index) const;
 
+  void ReadSegmentLoadCommand(
+    const LoadCommandInfo &LCI,
+    InMemoryStruct<macho::SegmentLoadCommand> &Res) const;
+  void ReadSegment64LoadCommand(
+    const LoadCommandInfo &LCI,
+    InMemoryStruct<macho::Segment64LoadCommand> &Res) const;
+
   /// @}
 };
 

lib/Object/MachOObject.cpp

@@ -16,11 +16,43 @@
 using namespace llvm;
 using namespace llvm::object;
 
+/* Translation Utilities */
+
 template<typename T>
 static void SwapValue(T &Value) {
   Value = sys::SwapByteOrder(Value);
 }
 
+template<typename T>
+static void SwapStruct(T &Value);
+
+template<typename T>
+static void ReadInMemoryStruct(const MachOObject &MOO,
+                               StringRef Buffer, uint64_t Base,
+                               InMemoryStruct<T> &Res) {
+  typedef T struct_type;
+  uint64_t Size = sizeof(struct_type);
+
+  // Check that the buffer contains the expected data.
+  if (Base + Size >  Buffer.size()) {
+    Res = 0;
+    return;
+  }
+
+  // Check whether we can return a direct pointer.
+  struct_type *Ptr = (struct_type *) (Buffer.data() + Base);
+  if (!MOO.isSwappedEndian()) {
+    Res = Ptr;
+    return;
+  }
+
+  // Otherwise, copy the struct and translate the values.
+  Res = *Ptr;
+  SwapStruct(*Res);
+}
+
+/* *** */
+
 MachOObject::MachOObject(MemoryBuffer *Buffer_, bool IsLittleEndian_,
                          bool Is64Bit_)
   : Buffer(Buffer_), IsLittleEndian(IsLittleEndian_), Is64Bit(Is64Bit_),
@@ -120,3 +152,39 @@ MachOObject::getLoadCommandInfo(unsigned Index) const {
 
   return LoadCommands[Index];
 }
+
+template<>
+static void SwapStruct(macho::SegmentLoadCommand &Value) {
+  SwapValue(Value.Type);
+  SwapValue(Value.Size);
+  SwapValue(Value.VMAddress);
+  SwapValue(Value.VMSize);
+  SwapValue(Value.FileOffset);
+  SwapValue(Value.FileSize);
+  SwapValue(Value.MaxVMProtection);
+  SwapValue(Value.InitialVMProtection);
+  SwapValue(Value.NumSections);
+  SwapValue(Value.Flags);
+}
+void MachOObject::ReadSegmentLoadCommand(const LoadCommandInfo &LCI,
+                         InMemoryStruct<macho::SegmentLoadCommand> &Res) const {
+  ReadInMemoryStruct(*this, Buffer->getBuffer(), LCI.Offset, Res);
+}
+
+template<>
+static void SwapStruct(macho::Segment64LoadCommand &Value) {
+  SwapValue(Value.Type);
+  SwapValue(Value.Size);
+  SwapValue(Value.VMAddress);
+  SwapValue(Value.VMSize);
+  SwapValue(Value.FileOffset);
+  SwapValue(Value.FileSize);
+  SwapValue(Value.MaxVMProtection);
+  SwapValue(Value.InitialVMProtection);
+  SwapValue(Value.NumSections);
+  SwapValue(Value.Flags);
+}
+void MachOObject::ReadSegment64LoadCommand(const LoadCommandInfo &LCI,
+                       InMemoryStruct<macho::Segment64LoadCommand> &Res) const {
+  ReadInMemoryStruct(*this, Buffer->getBuffer(), LCI.Offset, Res);
+}

tools/macho-dump/macho-dump.cpp

@@ -65,20 +65,73 @@ static int DumpHeader(MachOObject &Obj) {
   return 0;
 }
 
+static void DumpSegmentCommandData(StringRef Name,
+                                   uint64_t VMAddr, uint64_t VMSize,
+                                   uint64_t FileOffset, uint64_t FileSize,
+                                   uint32_t MaxProt, uint32_t InitProt,
+                                   uint32_t NumSections, uint32_t Flags) {
+  outs() << "  ('segment_name', '";
+  outs().write_escaped(Name, /*UseHexEscapes=*/true) << "')\n";
+  outs() << "  ('vm_addr', " << VMAddr << ")\n";
+  outs() << "  ('vm_size', " << VMSize << ")\n";
+  outs() << "  ('file_offset', " << FileOffset << ")\n";
+  outs() << "  ('file_size', " << FileSize << ")\n";
+  outs() << "  ('maxprot', " << MaxProt << ")\n";
+  outs() << "  ('initprot', " << InitProt << ")\n";
+  outs() << "  ('num_sections', " << NumSections << ")\n";
+  outs() << "  ('flags', " << Flags << ")\n";
+}
+
+static int DumpSegmentCommand(MachOObject &Obj,
+                               const MachOObject::LoadCommandInfo &LCI) {
+  InMemoryStruct<macho::SegmentLoadCommand> SLC;
+  Obj.ReadSegmentLoadCommand(LCI, SLC);
+  if (!SLC)
+    return Error("unable to read segment load command");
+
+  DumpSegmentCommandData(StringRef(SLC->Name, 16), SLC->VMAddress, SLC->VMSize,
+                         SLC->FileOffset, SLC->FileSize,
+                         SLC->MaxVMProtection, SLC->InitialVMProtection,
+                         SLC->NumSections, SLC->Flags);
+
+  return 0;
+}
+static int DumpSegment64Command(MachOObject &Obj,
+                               const MachOObject::LoadCommandInfo &LCI) {
+  InMemoryStruct<macho::Segment64LoadCommand> SLC;
+  Obj.ReadSegment64LoadCommand(LCI, SLC);
+  if (!SLC)
+    return Error("unable to read segment load command");
+
+  DumpSegmentCommandData(StringRef(SLC->Name, 16), SLC->VMAddress, SLC->VMSize,
+                         SLC->FileOffset, SLC->FileSize,
+                         SLC->MaxVMProtection, SLC->InitialVMProtection,
+                         SLC->NumSections, SLC->Flags);
+
+  return 0;
+}
+
 static int DumpLoadCommand(MachOObject &Obj, unsigned Index) {
   const MachOObject::LoadCommandInfo &LCI = Obj.getLoadCommandInfo(Index);
+  int Res = 0;
 
   outs() << "  # Load Command " << Index << "\n"
          << " (('command', " << LCI.Command.Type << ")\n"
          << "  ('size', " << LCI.Command.Size << ")\n";
   switch (LCI.Command.Type) {
+  case macho::LCT_Segment:
+    Res = DumpSegmentCommand(Obj, LCI);
+    break;
+  case macho::LCT_Segment64:
+    Res = DumpSegment64Command(Obj, LCI);
+    break;
   default:
     Warning("unknown load command: " + Twine(LCI.Command.Type));
     break;
   }
   outs() << " ),\n";
 
-  return 0;
+  return Res;
 }
 
 int main(int argc, char **argv) {
@@ -104,10 +157,12 @@ int main(int argc, char **argv) {
     return Res;
 
   // Print the load commands.
+  int Res = 0;
   outs() << "('load_commands', [\n";
   for (unsigned i = 0; i != InputObject->getHeader().NumLoadCommands; ++i)
-    DumpLoadCommand(*InputObject, i);
+    if ((Res = DumpLoadCommand(*InputObject, i)))
+      break;
   outs() << "])\n";
 
-  return 0;
+  return Res;
 }