[MCJIT] Add support for ARM HALF_DIFF relocations to MCJIT.

Fixes <rdar://problem/18297804>.

llvm-svn: 217620

1 files changed, 58 insertions, 0 deletions

diff --git a/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldMachO.cpp b/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldMachO.cpp
index 8e78317669a..c57f7763156 100644
--- a/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldMachO.cpp
+++ b/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldMachO.cpp
@@ -108,6 +108,64 @@ void RuntimeDyldMachO::dumpRelocationToResolve(const RelocationEntry &RE,
          << " Size: " << (1 << RE.Size) << "\n";
 }
 
+section_iterator
+RuntimeDyldMachO::getSectionByAddress(const MachOObjectFile &Obj,
+                                      uint64_t Addr) {
+  section_iterator SI = Obj.section_begin();
+  section_iterator SE = Obj.section_end();
+
+  for (; SI != SE; ++SI) {
+    uint64_t SAddr, SSize;
+    SI->getAddress(SAddr);
+    SI->getSize(SSize);
+    if ((Addr >= SAddr) && (Addr < SAddr + SSize))
+      return SI;
+  }
+
+  return SE;
+}
+
+
+// Populate __pointers section.
+void RuntimeDyldMachO::populateIndirectSymbolPointersSection(
+                                                    MachOObjectFile &Obj,
+                                                    const SectionRef &PTSection,
+                                                    unsigned PTSectionID) {
+  assert(!Obj.is64Bit() &&
+         "Pointer table section not supported in 64-bit MachO.");
+
+  MachO::dysymtab_command DySymTabCmd = Obj.getDysymtabLoadCommand();
+  MachO::section Sec32 = Obj.getSection(PTSection.getRawDataRefImpl());
+  uint32_t PTSectionSize = Sec32.size;
+  unsigned FirstIndirectSymbol = Sec32.reserved1;
+  const unsigned PTEntrySize = 4;
+  unsigned NumPTEntries = PTSectionSize / PTEntrySize;
+  unsigned PTEntryOffset = 0;
+
+  assert((PTSectionSize % PTEntrySize) == 0 &&
+         "Pointers section does not contain a whole number of stubs?");
+
+  DEBUG(dbgs() << "Populating pointer table section "
+               << Sections[PTSectionID].Name
+               << ", Section ID " << PTSectionID << ", "
+               << NumPTEntries << " entries, " << PTEntrySize
+               << " bytes each:\n");
+
+  for (unsigned i = 0; i < NumPTEntries; ++i) {
+    unsigned SymbolIndex =
+      Obj.getIndirectSymbolTableEntry(DySymTabCmd, FirstIndirectSymbol + i);
+    symbol_iterator SI = Obj.getSymbolByIndex(SymbolIndex);
+    StringRef IndirectSymbolName;
+    SI->getName(IndirectSymbolName);
+    DEBUG(dbgs() << "  " << IndirectSymbolName << ": index " << SymbolIndex
+          << ", PT offset: " << PTEntryOffset << "\n");
+    RelocationEntry RE(PTSectionID, PTEntryOffset,
+                       MachO::GENERIC_RELOC_VANILLA, 0, false, 2);
+    addRelocationForSymbol(RE, IndirectSymbolName);
+    PTEntryOffset += PTEntrySize;
+  }
+}
+
 bool
 RuntimeDyldMachO::isCompatibleFormat(const ObjectBuffer *InputBuffer) const {
   if (InputBuffer->getBufferSize() < 4)