1 files changed, 57 insertions, 0 deletions
diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp b/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
index 76b58684da8..0b7f0f339f7 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
@@ -743,4 +743,61 @@ void DwarfCompileUnit::addAddress(DIE &Die, dwarf::Attribute Attribute,
   // Now attach the location information to the DIE.
   addBlock(Die, Attribute, Loc);
 }
+
+/// Start with the address based on the location provided, and generate the
+/// DWARF information necessary to find the actual variable given the extra
+/// address information encoded in the DbgVariable, starting from the starting
+/// location.  Add the DWARF information to the die.
+void DwarfCompileUnit::addComplexAddress(const DbgVariable &DV, DIE &Die,
+                                         dwarf::Attribute Attribute,
+                                         const MachineLocation &Location) {
+  DIELoc *Loc = new (DIEValueAllocator) DIELoc();
+  unsigned N = DV.getNumAddrElements();
+  unsigned i = 0;
+  if (Location.isReg()) {
+    if (N >= 2 && DV.getAddrElement(0) == dwarf::DW_OP_plus) {
+      assert(!DV.getVariable().isIndirect() &&
+             "double indirection not handled");
+      // If first address element is OpPlus then emit
+      // DW_OP_breg + Offset instead of DW_OP_reg + Offset.
+      addRegisterOffset(*Loc, Location.getReg(), DV.getAddrElement(1));
+      i = 2;
+    } else if (N >= 2 && DV.getAddrElement(0) == dwarf::DW_OP_deref) {
+      assert(!DV.getVariable().isIndirect() &&
+             "double indirection not handled");
+      addRegisterOpPiece(*Loc, Location.getReg(),
+                         DV.getExpression().getPieceSize(),
+                         DV.getExpression().getPieceOffset());
+      i = 3;
+    } else
+      addRegisterOpPiece(*Loc, Location.getReg());
+  } else
+    addRegisterOffset(*Loc, Location.getReg(), Location.getOffset());
+
+  for (; i < N; ++i) {
+    uint64_t Element = DV.getAddrElement(i);
+    if (Element == dwarf::DW_OP_plus) {
+      addUInt(*Loc, dwarf::DW_FORM_data1, dwarf::DW_OP_plus_uconst);
+      addUInt(*Loc, dwarf::DW_FORM_udata, DV.getAddrElement(++i));
+
+    } else if (Element == dwarf::DW_OP_deref) {
+      if (!Location.isReg())
+        addUInt(*Loc, dwarf::DW_FORM_data1, dwarf::DW_OP_deref);
+
+    } else if (Element == dwarf::DW_OP_piece) {
+      const unsigned SizeOfByte = 8;
+      unsigned PieceOffsetInBits = DV.getAddrElement(++i) * SizeOfByte;
+      unsigned PieceSizeInBits = DV.getAddrElement(++i) * SizeOfByte;
+      // Emit DW_OP_bit_piece Size Offset.
+      assert(PieceSizeInBits > 0 && "piece has zero size");
+      addUInt(*Loc, dwarf::DW_FORM_data1, dwarf::DW_OP_bit_piece);
+      addUInt(*Loc, dwarf::DW_FORM_udata, PieceSizeInBits);
+      addUInt(*Loc, dwarf::DW_FORM_udata, PieceOffsetInBits);
+    } else
+      llvm_unreachable("unknown DIBuilder Opcode");
+  }
+
+  // Now attach the location information to the DIE.
+  addBlock(Die, Attribute, Loc);
+}
 } // end llvm namespace