Code cleanup in RuntimeDyld:

- Add comments
- Change field names to be more reasonable
- Fix indentation and naming to conform to coding conventions
- Remove unnecessary includes / replace them by forward declatations



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@155815 91177308-0d34-0410-b5e6-96231b3b80d8

4 files changed, 95 insertions, 72 deletions

diff --git a/lib/ExecutionEngine/RuntimeDyld/RuntimeDyld.cpp b/lib/ExecutionEngine/RuntimeDyld/RuntimeDyld.cpp
index e53b410099..644b7930c3 100644
--- a/lib/ExecutionEngine/RuntimeDyld/RuntimeDyld.cpp
+++ b/lib/ExecutionEngine/RuntimeDyld/RuntimeDyld.cpp
@@ -308,10 +308,10 @@ unsigned RuntimeDyldImpl::findOrEmitSection(ObjectImage &Obj,
   return SectionID;
 }
 
-void RuntimeDyldImpl::AddRelocation(const RelocationValueRef &Value,
+void RuntimeDyldImpl::addRelocation(const RelocationValueRef &Value,
                                     unsigned SectionID, uintptr_t Offset,
                                     uint32_t RelType) {
-  DEBUG(dbgs() << "AddRelocation SymNamePtr: " << format("%p", Value.SymbolName)
+  DEBUG(dbgs() << "addRelocation SymNamePtr: " << format("%p", Value.SymbolName)
                << " SID: " << Value.SectionID
                << " Addend: " << format("%p", Value.Addend)
                << " Offset: " << format("%p", Offset)
@@ -370,12 +370,12 @@ void RuntimeDyldImpl::resolveRelocationEntry(const RelocationEntry &RE,
       uint8_t *Target = Sections[RE.SectionID].Address + RE.Offset;
       DEBUG(dbgs() << "\tSectionID: " << RE.SectionID
             << " + " << RE.Offset << " (" << format("%p", Target) << ")"
-            << " Data: " << RE.Data
+            << " RelType: " << RE.RelType
             << " Addend: " << RE.Addend
             << "\n");
 
       resolveRelocation(Target, Sections[RE.SectionID].LoadAddress + RE.Offset,
-                        Value, RE.Data, RE.Addend);
+                        Value, RE.RelType, RE.Addend);
   }
 }
 
diff --git a/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldELF.cpp b/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldELF.cpp
index db6da8c8ef..748693c6e1 100644
--- a/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldELF.cpp
+++ b/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldELF.cpp
@@ -410,14 +410,14 @@ void RuntimeDyldELF::processRelocationRef(const ObjRelocationInfo &Rel,
       Stubs[Value] = Section.StubOffset;
       uint8_t *StubTargetAddr = createStubFunction(Section.Address +
                                                    Section.StubOffset);
-      AddRelocation(Value, Rel.SectionID,
+      addRelocation(Value, Rel.SectionID,
                     StubTargetAddr - Section.Address, ELF::R_ARM_ABS32);
       resolveRelocation(Target, (uint64_t)Target, (uint64_t)Section.Address +
                         Section.StubOffset, RelType, 0);
       Section.StubOffset += getMaxStubSize();
     }
   } else
-    AddRelocation(Value, Rel.SectionID, Rel.Offset, RelType);
+    addRelocation(Value, Rel.SectionID, Rel.Offset, RelType);
 }
 
 bool RuntimeDyldELF::isCompatibleFormat(const MemoryBuffer *InputBuffer) const {
diff --git a/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldImpl.h b/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldImpl.h
index 80f5f1e600..e97e5859e0 100644
--- a/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldImpl.h
+++ b/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldImpl.h
@@ -14,60 +14,83 @@
 #ifndef LLVM_RUNTIME_DYLD_IMPL_H
 #define LLVM_RUNTIME_DYLD_IMPL_H
 
+#include "ObjectImage.h"
 #include "llvm/ExecutionEngine/RuntimeDyld.h"
-#include "llvm/Object/ObjectFile.h"
 #include "llvm/ADT/DenseMap.h"
-#include "llvm/ADT/StringMap.h"
-#include "llvm/ADT/Twine.h"
 #include "llvm/ADT/SmallVector.h"
-#include "llvm/Support/Memory.h"
-#include "llvm/Support/MemoryBuffer.h"
-#include "llvm/Support/system_error.h"
-#include "llvm/Support/raw_ostream.h"
+#include "llvm/ADT/StringMap.h"
+#include "llvm/ADT/Triple.h"
+#include "llvm/Object/ObjectFile.h"
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/ErrorHandling.h"
-#include "llvm/ADT/Triple.h"
-#include <map>
 #include "llvm/Support/Format.h"
-#include "ObjectImage.h"
+#include "llvm/Support/raw_ostream.h"
+#include "llvm/Support/system_error.h"
+#include <map>
 
 using namespace llvm;
 using namespace llvm::object;
 
 namespace llvm {
 
+class MemoryBuffer;
+class Twine;
+
+
+/// SectionEntry - represents a section emitted into memory by the dynamic
+/// linker.
 class SectionEntry {
 public:
-  uint8_t  *Address;
-  size_t   Size;
-  uint64_t LoadAddress;   // For each section, the address it will be
-                          // considered to live at for relocations. The same
-                          // as the pointer to the above memory block for
-                          // hosted JITs.
-  uintptr_t StubOffset;   // It's used for architectures with stub
-                          // functions for far relocations like ARM.
-  uintptr_t ObjAddress;   // Section address in object file. It's used for
-                          // calculating the MachO relocation addend.
+  /// Address - address in the linker's memory where the section resides.
+  uint8_t *Address;
+
+  /// Size - section size.
+  size_t Size;
+
+  /// LoadAddress - the address of the section in the target process's memory.
+  /// Used for situations in which JIT-ed code is being executed in the address
+  /// space of a separate process.  If the code executes in the same address
+  /// space where it was JIT-ed, this just equals Address.
+  uint64_t LoadAddress;
+
+  /// StubOffset - used for architectures with stub functions for far
+  /// relocations (like ARM).
+  uintptr_t StubOffset;
+
+  /// ObjAddress - address of the section in the in-memory object file.  Used
+  /// for calculating relocations in some object formats (like MachO).
+  uintptr_t ObjAddress;
+
   SectionEntry(uint8_t *address, size_t size, uintptr_t stubOffset,
                uintptr_t objAddress)
     : Address(address), Size(size), LoadAddress((uintptr_t)address),
       StubOffset(stubOffset), ObjAddress(objAddress) {}
 };
 
+/// RelocationEntry - used to represent relocations internally in the dynamic
+/// linker.
 class RelocationEntry {
 public:
-  unsigned    SectionID;  // Section the relocation is contained in.
-  uintptr_t   Offset;     // Offset into the section for the relocation.
-  uint32_t    Data;       // Relocation data. Including type of relocation
-                          // and other flags.
-  intptr_t    Addend;     // Addend encoded in the instruction itself, if any,
-                          // plus the offset into the source section for
-                          // the symbol once the relocation is resolvable.
-  RelocationEntry(unsigned id, uint64_t offset, uint32_t data, int64_t addend)
-    : SectionID(id), Offset(offset), Data(data), Addend(addend) {}
+  /// SectionID - the section this relocation points to.
+  unsigned SectionID;
+
+  /// Offset - offset into the section.
+  uintptr_t Offset;
+
+  /// RelType - relocation type.
+  uint32_t RelType;
+
+  /// Addend - the relocation addend encoded in the instruction itself.  Also
+  /// used to make a relocation section relative instead of symbol relative.
+  intptr_t Addend;
+
+  RelocationEntry(unsigned id, uint64_t offset, uint32_t type, int64_t addend)
+    : SectionID(id), Offset(offset), RelType(type), Addend(addend) {}
 };
 
-// Raw relocation data from object file
+/// ObjRelocationInfo - relocation information as read from the object file.
+/// Used to pass around data taken from object::RelocationRef, together with
+/// the section to which the relocation points (represented by a SectionID).
 class ObjRelocationInfo {
 public:
   unsigned  SectionID;
@@ -97,7 +120,8 @@ protected:
   // The MemoryManager to load objects into.
   RTDyldMemoryManager *MemMgr;
 
-  // A list of emmitted sections.
+  // A list of all sections emitted by the dynamic linker.  These sections are
+  // referenced in the code by means of their index in this list - SectionID.
   typedef SmallVector<SectionEntry, 64> SectionList;
   SectionList Sections;
 
@@ -180,7 +204,7 @@ protected:
 
   /// \brief If Value.SymbolName is NULL then store relocation to the
   ///        Relocations, else store it in the SymbolRelocations.
-  void AddRelocation(const RelocationValueRef &Value, unsigned SectionID,
+  void addRelocation(const RelocationValueRef &Value, unsigned SectionID,
                      uintptr_t Offset, uint32_t RelType);
 
   /// \brief Emits long jump instruction to Addr.
diff --git a/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldMachO.cpp b/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldMachO.cpp
index b7f515d6ce..a9574eb0ba 100644
--- a/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldMachO.cpp
+++ b/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldMachO.cpp
@@ -30,7 +30,8 @@ void RuntimeDyldMachO::resolveRelocation(uint8_t *LocalAddress,
   unsigned MachoType = (Type >> 28) & 0xf;
   unsigned Size = 1 << ((Type >> 25) & 3);
 
-  DEBUG(dbgs() << "resolveRelocation LocalAddress: " << format("%p", LocalAddress)
+  DEBUG(dbgs() << "resolveRelocation LocalAddress: " 
+        << format("%p", LocalAddress)
         << " FinalAddress: " << format("%p", FinalAddress)
         << " Value: " << format("%p", Value)
         << " Addend: " << Addend
@@ -53,12 +54,12 @@ void RuntimeDyldMachO::resolveRelocation(uint8_t *LocalAddress,
     break;
   case Triple::x86:
     resolveI386Relocation(LocalAddress,
-                                 FinalAddress,
-                                 (uintptr_t)Value,
-                                 isPCRel,
-                                 Type,
-                                 Size,
-                                 Addend);
+                          FinalAddress,
+                          (uintptr_t)Value,
+                          isPCRel,
+                          Type,
+                          Size,
+                          Addend);
     break;
   case Triple::arm:    // Fall through.
   case Triple::thumb:
@@ -73,14 +74,13 @@ void RuntimeDyldMachO::resolveRelocation(uint8_t *LocalAddress,
   }
 }
 
-bool RuntimeDyldMachO::
-resolveI386Relocation(uint8_t *LocalAddress,
-                      uint64_t FinalAddress,
-                      uint64_t Value,
-                      bool isPCRel,
-                      unsigned Type,
-                      unsigned Size,
-                      int64_t Addend) {
+bool RuntimeDyldMachO::resolveI386Relocation(uint8_t *LocalAddress,
+                                             uint64_t FinalAddress,
+                                             uint64_t Value,
+                                             bool isPCRel,
+                                             unsigned Type,
+                                             unsigned Size,
+                                             int64_t Addend) {
   if (isPCRel)
     Value -= FinalAddress + 4; // see resolveX86_64Relocation
 
@@ -102,14 +102,13 @@ resolveI386Relocation(uint8_t *LocalAddress,
   }
 }
 
-bool RuntimeDyldMachO::
-resolveX86_64Relocation(uint8_t *LocalAddress,
-                        uint64_t FinalAddress,
-                        uint64_t Value,
-                        bool isPCRel,
-                        unsigned Type,
-                        unsigned Size,
-                        int64_t Addend) {
+bool RuntimeDyldMachO::resolveX86_64Relocation(uint8_t *LocalAddress,
+                                               uint64_t FinalAddress,
+                                               uint64_t Value,
+                                               bool isPCRel,
+                                               unsigned Type,
+                                               unsigned Size,
+                                               int64_t Addend) {
   // If the relocation is PC-relative, the value to be encoded is the
   // pointer difference.
   if (isPCRel)
@@ -144,14 +143,13 @@ resolveX86_64Relocation(uint8_t *LocalAddress,
   }
 }
 
-bool RuntimeDyldMachO::
-resolveARMRelocation(uint8_t *LocalAddress,
-                     uint64_t FinalAddress,
-                     uint64_t Value,
-                     bool isPCRel,
-                     unsigned Type,
-                     unsigned Size,
-                     int64_t Addend) {
+bool RuntimeDyldMachO::resolveARMRelocation(uint8_t *LocalAddress,
+                                            uint64_t FinalAddress,
+                                            uint64_t Value,
+                                            bool isPCRel,
+                                            unsigned Type,
+                                            unsigned Size,
+                                            int64_t Addend) {
   // If the relocation is PC-relative, the value to be encoded is the
   // pointer difference.
   if (isPCRel) {
@@ -269,7 +267,7 @@ void RuntimeDyldMachO::processRelocationRef(const ObjRelocationInfo &Rel,
       Stubs[Value] = Section.StubOffset;
       uint8_t *StubTargetAddr = createStubFunction(Section.Address +
                                                    Section.StubOffset);
-      AddRelocation(Value, Rel.SectionID, StubTargetAddr - Section.Address,
+      addRelocation(Value, Rel.SectionID, StubTargetAddr - Section.Address,
                     macho::RIT_Vanilla);
       resolveRelocation(Target, (uint64_t)Target,
                         (uint64_t)Section.Address + Section.StubOffset,
@@ -277,11 +275,12 @@ void RuntimeDyldMachO::processRelocationRef(const ObjRelocationInfo &Rel,
       Section.StubOffset += getMaxStubSize();
     }
   } else
-    AddRelocation(Value, Rel.SectionID, Rel.Offset, RelType);
+    addRelocation(Value, Rel.SectionID, Rel.Offset, RelType);
 }
 
 
-bool RuntimeDyldMachO::isCompatibleFormat(const MemoryBuffer *InputBuffer) const {
+bool RuntimeDyldMachO::isCompatibleFormat(
+        const MemoryBuffer *InputBuffer) const {
   StringRef Magic = InputBuffer->getBuffer().slice(0, 4);
   if (Magic == "\xFE\xED\xFA\xCE") return true;
   if (Magic == "\xCE\xFA\xED\xFE") return true;