1 files changed, 280 insertions, 0 deletions
diff --git a/contrib/llvm/lib/ExecutionEngine/RuntimeDyld/Targets/RuntimeDyldMachOARM.h b/contrib/llvm/lib/ExecutionEngine/RuntimeDyld/Targets/RuntimeDyldMachOARM.h
new file mode 100644
index 0000000..7731df0
--- /dev/null
+++ b/contrib/llvm/lib/ExecutionEngine/RuntimeDyld/Targets/RuntimeDyldMachOARM.h
@@ -0,0 +1,280 @@
+//===----- RuntimeDyldMachOARM.h ---- MachO/ARM specific code. ----*- C++ -*-=//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIB_EXECUTIONENGINE_RUNTIMEDYLD_TARGETS_RUNTIMEDYLDMACHOARM_H
+#define LLVM_LIB_EXECUTIONENGINE_RUNTIMEDYLD_TARGETS_RUNTIMEDYLDMACHOARM_H
+
+#include "../RuntimeDyldMachO.h"
+
+#define DEBUG_TYPE "dyld"
+
+namespace llvm {
+
+class RuntimeDyldMachOARM
+    : public RuntimeDyldMachOCRTPBase<RuntimeDyldMachOARM> {
+private:
+  typedef RuntimeDyldMachOCRTPBase<RuntimeDyldMachOARM> ParentT;
+
+public:
+
+  typedef uint32_t TargetPtrT;
+
+  RuntimeDyldMachOARM(RuntimeDyld::MemoryManager &MM,
+                      RuntimeDyld::SymbolResolver &Resolver)
+    : RuntimeDyldMachOCRTPBase(MM, Resolver) {}
+
+  unsigned getMaxStubSize() override { return 8; }
+
+  unsigned getStubAlignment() override { return 4; }
+
+  int64_t decodeAddend(const RelocationEntry &RE) const {
+    const SectionEntry &Section = Sections[RE.SectionID];
+    uint8_t *LocalAddress = Section.getAddressWithOffset(RE.Offset);
+
+    switch (RE.RelType) {
+      default:
+        return memcpyAddend(RE);
+      case MachO::ARM_RELOC_BR24: {
+        uint32_t Temp = readBytesUnaligned(LocalAddress, 4);
+        Temp &= 0x00ffffff; // Mask out the opcode.
+        // Now we've got the shifted immediate, shift by 2, sign extend and ret.
+        return SignExtend32<26>(Temp << 2);
+      }
+    }
+  }
+
+  relocation_iterator
+  processRelocationRef(unsigned SectionID, relocation_iterator RelI,
+                       const ObjectFile &BaseObjT,
+                       ObjSectionToIDMap &ObjSectionToID,
+                       StubMap &Stubs) override {
+    const MachOObjectFile &Obj =
+        static_cast<const MachOObjectFile &>(BaseObjT);
+    MachO::any_relocation_info RelInfo =
+        Obj.getRelocation(RelI->getRawDataRefImpl());
+    uint32_t RelType = Obj.getAnyRelocationType(RelInfo);
+
+    if (Obj.isRelocationScattered(RelInfo)) {
+      if (RelType == MachO::ARM_RELOC_HALF_SECTDIFF)
+        return processHALFSECTDIFFRelocation(SectionID, RelI, Obj,
+                                             ObjSectionToID);
+      else if (RelType == MachO::GENERIC_RELOC_VANILLA)
+        return processScatteredVANILLA(SectionID, RelI, Obj, ObjSectionToID);
+      else
+        return ++RelI;
+    }
+
+    RelocationEntry RE(getRelocationEntry(SectionID, Obj, RelI));
+    RE.Addend = decodeAddend(RE);
+    RelocationValueRef Value(
+        getRelocationValueRef(Obj, RelI, RE, ObjSectionToID));
+
+    if (RE.IsPCRel)
+      makeValueAddendPCRel(Value, RelI, 8);
+
+    if ((RE.RelType & 0xf) == MachO::ARM_RELOC_BR24)
+      processBranchRelocation(RE, Value, Stubs);
+    else {
+      RE.Addend = Value.Offset;
+      if (Value.SymbolName)
+        addRelocationForSymbol(RE, Value.SymbolName);
+      else
+        addRelocationForSection(RE, Value.SectionID);
+    }
+
+    return ++RelI;
+  }
+
+  void resolveRelocation(const RelocationEntry &RE, uint64_t Value) override {
+    DEBUG(dumpRelocationToResolve(RE, Value));
+    const SectionEntry &Section = Sections[RE.SectionID];
+    uint8_t *LocalAddress = Section.getAddressWithOffset(RE.Offset);
+
+    // If the relocation is PC-relative, the value to be encoded is the
+    // pointer difference.
+    if (RE.IsPCRel) {
+      uint64_t FinalAddress = Section.getLoadAddressWithOffset(RE.Offset);
+      Value -= FinalAddress;
+      // ARM PCRel relocations have an effective-PC offset of two instructions
+      // (four bytes in Thumb mode, 8 bytes in ARM mode).
+      // FIXME: For now, assume ARM mode.
+      Value -= 8;
+    }
+
+    switch (RE.RelType) {
+    default:
+      llvm_unreachable("Invalid relocation type!");
+    case MachO::ARM_RELOC_VANILLA:
+      writeBytesUnaligned(Value + RE.Addend, LocalAddress, 1 << RE.Size);
+      break;
+    case MachO::ARM_RELOC_BR24: {
+      // Mask the value into the target address. We know instructions are
+      // 32-bit aligned, so we can do it all at once.
+      Value += RE.Addend;
+      // The low two bits of the value are not encoded.
+      Value >>= 2;
+      // Mask the value to 24 bits.
+      uint64_t FinalValue = Value & 0xffffff;
+      // FIXME: If the destination is a Thumb function (and the instruction
+      // is a non-predicated BL instruction), we need to change it to a BLX
+      // instruction instead.
+
+      // Insert the value into the instruction.
+      uint32_t Temp = readBytesUnaligned(LocalAddress, 4);
+      writeBytesUnaligned((Temp & ~0xffffff) | FinalValue, LocalAddress, 4);
+
+      break;
+    }
+    case MachO::ARM_RELOC_HALF_SECTDIFF: {
+      uint64_t SectionABase = Sections[RE.Sections.SectionA].getLoadAddress();
+      uint64_t SectionBBase = Sections[RE.Sections.SectionB].getLoadAddress();
+      assert((Value == SectionABase || Value == SectionBBase) &&
+             "Unexpected HALFSECTDIFF relocation value.");
+      Value = SectionABase - SectionBBase + RE.Addend;
+      if (RE.Size & 0x1) // :upper16:
+        Value = (Value >> 16);
+      Value &= 0xffff;
+
+      uint32_t Insn = readBytesUnaligned(LocalAddress, 4);
+      Insn = (Insn & 0xfff0f000) | ((Value & 0xf000) << 4) | (Value & 0x0fff);
+      writeBytesUnaligned(Insn, LocalAddress, 4);
+      break;
+    }
+
+    case MachO::ARM_THUMB_RELOC_BR22:
+    case MachO::ARM_THUMB_32BIT_BRANCH:
+    case MachO::ARM_RELOC_HALF:
+    case MachO::ARM_RELOC_PAIR:
+    case MachO::ARM_RELOC_SECTDIFF:
+    case MachO::ARM_RELOC_LOCAL_SECTDIFF:
+    case MachO::ARM_RELOC_PB_LA_PTR:
+      Error("Relocation type not implemented yet!");
+      return;
+    }
+  }
+
+  void finalizeSection(const ObjectFile &Obj, unsigned SectionID,
+                       const SectionRef &Section) {
+    StringRef Name;
+    Section.getName(Name);
+
+    if (Name == "__nl_symbol_ptr")
+      populateIndirectSymbolPointersSection(cast<MachOObjectFile>(Obj),
+                                            Section, SectionID);
+  }
+
+private:
+
+  void processBranchRelocation(const RelocationEntry &RE,
+                               const RelocationValueRef &Value,
+                               StubMap &Stubs) {
+    // This is an ARM branch relocation, need to use a stub function.
+    // Look up for existing stub.
+    SectionEntry &Section = Sections[RE.SectionID];
+    RuntimeDyldMachO::StubMap::const_iterator i = Stubs.find(Value);
+    uint8_t *Addr;
+    if (i != Stubs.end()) {
+      Addr = Section.getAddressWithOffset(i->second);
+    } else {
+      // Create a new stub function.
+      Stubs[Value] = Section.getStubOffset();
+      uint8_t *StubTargetAddr = createStubFunction(
+          Section.getAddressWithOffset(Section.getStubOffset()));
+      RelocationEntry StubRE(
+          RE.SectionID, StubTargetAddr - Section.getAddress(),
+          MachO::GENERIC_RELOC_VANILLA, Value.Offset, false, 2);
+      if (Value.SymbolName)
+        addRelocationForSymbol(StubRE, Value.SymbolName);
+      else
+        addRelocationForSection(StubRE, Value.SectionID);
+      Addr = Section.getAddressWithOffset(Section.getStubOffset());
+      Section.advanceStubOffset(getMaxStubSize());
+    }
+    RelocationEntry TargetRE(RE.SectionID, RE.Offset, RE.RelType, 0,
+                             RE.IsPCRel, RE.Size);
+    resolveRelocation(TargetRE, (uint64_t)Addr);
+  }
+
+  relocation_iterator
+  processHALFSECTDIFFRelocation(unsigned SectionID, relocation_iterator RelI,
+                                const ObjectFile &BaseTObj,
+                                ObjSectionToIDMap &ObjSectionToID) {
+    const MachOObjectFile &MachO =
+        static_cast<const MachOObjectFile&>(BaseTObj);
+    MachO::any_relocation_info RE =
+        MachO.getRelocation(RelI->getRawDataRefImpl());
+
+
+    // For a half-diff relocation the length bits actually record whether this
+    // is a movw/movt, and whether this is arm or thumb.
+    // Bit 0 indicates movw (b0 == 0) or movt (b0 == 1).
+    // Bit 1 indicates arm (b1 == 0) or thumb (b1 == 1).
+    unsigned HalfDiffKindBits = MachO.getAnyRelocationLength(RE);
+    if (HalfDiffKindBits & 0x2)
+      llvm_unreachable("Thumb not yet supported.");
+
+    SectionEntry &Section = Sections[SectionID];
+    uint32_t RelocType = MachO.getAnyRelocationType(RE);
+    bool IsPCRel = MachO.getAnyRelocationPCRel(RE);
+    uint64_t Offset = RelI->getOffset();
+    uint8_t *LocalAddress = Section.getAddressWithOffset(Offset);
+    int64_t Immediate = readBytesUnaligned(LocalAddress, 4); // Copy the whole instruction out.
+    Immediate = ((Immediate >> 4) & 0xf000) | (Immediate & 0xfff);
+
+    ++RelI;
+    MachO::any_relocation_info RE2 =
+      MachO.getRelocation(RelI->getRawDataRefImpl());
+    uint32_t AddrA = MachO.getScatteredRelocationValue(RE);
+    section_iterator SAI = getSectionByAddress(MachO, AddrA);
+    assert(SAI != MachO.section_end() && "Can't find section for address A");
+    uint64_t SectionABase = SAI->getAddress();
+    uint64_t SectionAOffset = AddrA - SectionABase;
+    SectionRef SectionA = *SAI;
+    bool IsCode = SectionA.isText();
+    uint32_t SectionAID =
+        findOrEmitSection(MachO, SectionA, IsCode, ObjSectionToID);
+
+    uint32_t AddrB = MachO.getScatteredRelocationValue(RE2);
+    section_iterator SBI = getSectionByAddress(MachO, AddrB);
+    assert(SBI != MachO.section_end() && "Can't find section for address B");
+    uint64_t SectionBBase = SBI->getAddress();
+    uint64_t SectionBOffset = AddrB - SectionBBase;
+    SectionRef SectionB = *SBI;
+    uint32_t SectionBID =
+        findOrEmitSection(MachO, SectionB, IsCode, ObjSectionToID);
+
+    uint32_t OtherHalf = MachO.getAnyRelocationAddress(RE2) & 0xffff;
+    unsigned Shift = (HalfDiffKindBits & 0x1) ? 16 : 0;
+    uint32_t FullImmVal = (Immediate << Shift) | (OtherHalf << (16 - Shift));
+    int64_t Addend = FullImmVal - (AddrA - AddrB);
+
+    // addend = Encoded - Expected
+    //        = Encoded - (AddrA - AddrB)
+
+    DEBUG(dbgs() << "Found SECTDIFF: AddrA: " << AddrA << ", AddrB: " << AddrB
+                 << ", Addend: " << Addend << ", SectionA ID: " << SectionAID
+                 << ", SectionAOffset: " << SectionAOffset
+                 << ", SectionB ID: " << SectionBID
+                 << ", SectionBOffset: " << SectionBOffset << "\n");
+    RelocationEntry R(SectionID, Offset, RelocType, Addend, SectionAID,
+                      SectionAOffset, SectionBID, SectionBOffset, IsPCRel,
+                      HalfDiffKindBits);
+
+    addRelocationForSection(R, SectionAID);
+    addRelocationForSection(R, SectionBID);
+
+    return ++RelI;
+  }
+
+};
+}
+
+#undef DEBUG_TYPE
+
+#endif