#include "llvm/Object/MachO.h"
#include "llvm/Support/Format.h"
+#define DEBUG_TYPE "dyld"
+
using namespace llvm;
using namespace llvm::object;
namespace llvm {
class RuntimeDyldMachO : public RuntimeDyldImpl {
-private:
-
- /// Write the least significant 'Size' bytes in 'Value' out at the address
- /// pointed to by Addr.
- bool applyRelocationValue(uint8_t *Addr, uint64_t Value, unsigned Size) {
- for (unsigned i = 0; i < Size; ++i) {
- *Addr++ = (uint8_t)Value;
- Value >>= 8;
- }
-
- return false;
- }
-
- bool resolveI386Relocation(const RelocationEntry &RE, uint64_t Value);
- bool resolveX86_64Relocation(const RelocationEntry &RE, uint64_t Value);
- bool resolveARMRelocation(const RelocationEntry &RE, uint64_t Value);
- bool resolveAArch64Relocation(const RelocationEntry &RE, uint64_t Value);
-
- // Populate stubs in __jump_table section.
- void populateJumpTable(MachOObjectFile &Obj, const SectionRef &JTSection,
- unsigned JTSectionID);
-
- // Populate __pointers section.
- void populatePointersSection(MachOObjectFile &Obj, const SectionRef &PTSection,
- unsigned PTSectionID);
-
- unsigned getMaxStubSize() override {
- if (Arch == Triple::arm || Arch == Triple::thumb)
- return 8; // 32-bit instruction and 32-bit address
- else if (Arch == Triple::x86_64)
- return 8; // GOT entry
- else if (Arch == Triple::arm64)
- return 8; // GOT entry
- else
- return 0;
- }
-
- unsigned getStubAlignment() override {
- if (Arch == Triple::arm || Arch == Triple::thumb)
- return 4;
- else if (Arch == Triple::arm64)
- return 8;
- else
- return 1;
- }
-
- relocation_iterator processSECTDIFFRelocation(
- unsigned SectionID,
- relocation_iterator RelI,
- ObjectImage &ObjImg,
- ObjSectionToIDMap &ObjSectionToID);
-
- relocation_iterator processI386ScatteredVANILLA(
- unsigned SectionID,
- relocation_iterator RelI,
- ObjectImage &ObjImg,
- ObjSectionToIDMap &ObjSectionToID);
+protected:
+ struct SectionOffsetPair {
+ unsigned SectionID;
+ uint64_t Offset;
+ };
struct EHFrameRelatedSections {
EHFrameRelatedSections()
// EH frame sections with the memory manager.
SmallVector<EHFrameRelatedSections, 2> UnregisteredEHFrameSections;
-public:
RuntimeDyldMachO(RTDyldMemoryManager *mm) : RuntimeDyldImpl(mm) {}
- void resolveRelocation(const RelocationEntry &RE, uint64_t Value) override;
- relocation_iterator
- processRelocationRef(unsigned SectionID, relocation_iterator RelI,
- ObjectImage &Obj, ObjSectionToIDMap &ObjSectionToID,
- const SymbolTableMap &Symbols, StubMap &Stubs) override;
- bool isCompatibleFormat(const ObjectBuffer *Buffer) const override;
- bool isCompatibleFile(const object::ObjectFile *Obj) const override;
- void registerEHFrames() override;
- void finalizeLoad(ObjectImage &ObjImg,
- ObjSectionToIDMap &SectionMap) override;
+ /// Extract the addend encoded in the instruction.
+ uint64_t decodeAddend(uint8_t *LocalAddress, unsigned NumBytes,
+ uint32_t RelType) const;
+
+ /// Construct a RelocationValueRef representing the relocation target.
+ /// For Symbols in known sections, this will return a RelocationValueRef
+ /// representing a (SectionID, Offset) pair.
+ /// For Symbols whose section is not known, this will return a
+ /// (SymbolName, Offset) pair, where the Offset is taken from the instruction
+ /// immediate (held in RE.Addend).
+ /// In both cases the Addend field is *NOT* fixed up to be PC-relative. That
+ /// should be done by the caller where appropriate by calling makePCRel on
+ /// the RelocationValueRef.
+ RelocationValueRef getRelocationValueRef(ObjectImage &ObjImg,
+ const relocation_iterator &RI,
+ const RelocationEntry &RE,
+ ObjSectionToIDMap &ObjSectionToID,
+ const SymbolTableMap &Symbols);
+
+ /// Make the RelocationValueRef addend PC-relative.
+ void makeValueAddendPCRel(RelocationValueRef &Value, ObjectImage &ObjImg,
+ const relocation_iterator &RI);
+
+ /// Dump information about the relocation entry (RE) and resolved value.
+ void dumpRelocationToResolve(const RelocationEntry &RE, uint64_t Value) const;
+public:
+ /// Create an ObjectImage from the given ObjectBuffer.
static ObjectImage *createObjectImage(ObjectBuffer *InputBuffer) {
return new ObjectImageCommon(InputBuffer);
}
+ /// Create an ObjectImage from the given ObjectFile.
static ObjectImage *
createObjectImageFromFile(std::unique_ptr<object::ObjectFile> InputObject) {
return new ObjectImageCommon(std::move(InputObject));
}
+
+ /// Create a RuntimeDyldMachO instance for the given target architecture.
+ static std::unique_ptr<RuntimeDyldMachO> create(Triple::ArchType Arch,
+ RTDyldMemoryManager *mm);
+
+ /// Write the least significant 'Size' bytes in 'Value' out at the address
+ /// pointed to by Addr. Check for overflow.
+ bool writeBytesUnaligned(uint8_t *Addr, uint64_t Value, unsigned Size);
+
+ SectionEntry &getSection(unsigned SectionID) { return Sections[SectionID]; }
+
+ bool isCompatibleFormat(const ObjectBuffer *Buffer) const override;
+ bool isCompatibleFile(const object::ObjectFile *Obj) const override;
+ void registerEHFrames() override;
+};
+
+/// RuntimeDyldMachOTarget - Templated base class for generic MachO linker
+/// algorithms and data structures.
+///
+/// Concrete, target specific sub-classes can be accessed via the impl()
+/// methods. (i.e. the RuntimeDyldMachO hierarchy uses the Curiously
+/// Recurring Template Idiom). Concrete subclasses for each target
+/// can be found in ./Targets.
+template <typename Impl>
+class RuntimeDyldMachOCRTPBase : public RuntimeDyldMachO {
+private:
+ Impl &impl() { return static_cast<Impl &>(*this); }
+ const Impl &impl() const { return static_cast<const Impl &>(*this); }
+
+protected:
+
+ /// Parse the given relocation, which must be a non-scattered, and
+ /// return a RelocationEntry representing the information. The 'Addend' field
+ /// will contain the unmodified instruction immediate.
+ RelocationEntry getBasicRelocationEntry(unsigned SectionID,
+ ObjectImage &ObjImg,
+ const relocation_iterator &RI) const {
+ const MachOObjectFile &Obj =
+ static_cast<const MachOObjectFile &>(*ObjImg.getObjectFile());
+ MachO::any_relocation_info RelInfo =
+ Obj.getRelocation(RI->getRawDataRefImpl());
+
+ const SectionEntry &Section = Sections[SectionID];
+ bool IsPCRel = Obj.getAnyRelocationPCRel(RelInfo);
+ unsigned Size = Obj.getAnyRelocationLength(RelInfo);
+ uint64_t Offset;
+ RI->getOffset(Offset);
+ uint8_t *LocalAddress = Section.Address + Offset;
+ unsigned NumBytes = 1 << Size;
+ uint32_t RelType = Obj.getAnyRelocationType(RelInfo);
+ uint64_t Addend = impl().decodeAddend(LocalAddress, NumBytes, RelType);
+
+ return RelocationEntry(SectionID, Offset, RelType, Addend, IsPCRel, Size);
+ }
+
+public:
+ RuntimeDyldMachOCRTPBase(RTDyldMemoryManager *mm) : RuntimeDyldMachO(mm) {}
+
+ void finalizeLoad(ObjectImage &ObjImg, ObjSectionToIDMap &SectionMap) {
+ unsigned EHFrameSID = RTDYLD_INVALID_SECTION_ID;
+ unsigned TextSID = RTDYLD_INVALID_SECTION_ID;
+ unsigned ExceptTabSID = RTDYLD_INVALID_SECTION_ID;
+ ObjSectionToIDMap::iterator i, e;
+
+ for (i = SectionMap.begin(), e = SectionMap.end(); i != e; ++i) {
+ const SectionRef &Section = i->first;
+ StringRef Name;
+ Section.getName(Name);
+ if (Name == "__eh_frame")
+ EHFrameSID = i->second;
+ else if (Name == "__text")
+ TextSID = i->second;
+ else if (Name == "__gcc_except_tab")
+ ExceptTabSID = i->second;
+ else
+ impl().finalizeSection(ObjImg, i->second, Section);
+ }
+ UnregisteredEHFrameSections.push_back(
+ EHFrameRelatedSections(EHFrameSID, TextSID, ExceptTabSID));
+ }
};
} // end namespace llvm
+#undef DEBUG_TYPE
+
#endif