1 files changed, 39 insertions, 0 deletions
diff --git a/lib/MC/MCObjectWriter.cpp b/lib/MC/MCObjectWriter.cpp
index 6cee76d..efe9f68 100644
--- a/lib/MC/MCObjectWriter.cpp
+++ b/lib/MC/MCObjectWriter.cpp
@@ -7,7 +7,10 @@
 //
 //===----------------------------------------------------------------------===//
 
+#include "llvm/MC/MCAssembler.h"
+#include "llvm/MC/MCExpr.h"
 #include "llvm/MC/MCObjectWriter.h"
+#include "llvm/MC/MCSymbol.h"
 
 using namespace llvm;
 
@@ -39,3 +42,39 @@ void MCObjectWriter::EncodeULEB128(uint64_t Value, raw_ostream &OS) {
     OS << char(Byte);
   } while (Value != 0);
 }
+
+bool
+MCObjectWriter::IsSymbolRefDifferenceFullyResolved(const MCAssembler &Asm,
+                                                   const MCSymbolRefExpr *A,
+                                                   const MCSymbolRefExpr *B,
+                                                   bool InSet) const {
+  // Modified symbol references cannot be resolved.
+  if (A->getKind() != MCSymbolRefExpr::VK_None ||
+      B->getKind() != MCSymbolRefExpr::VK_None)
+    return false;
+
+  const MCSymbol &SA = A->getSymbol();
+  const MCSymbol &SB = B->getSymbol();
+  if (SA.AliasedSymbol().isUndefined() || SB.AliasedSymbol().isUndefined())
+    return false;
+
+  const MCSymbolData &DataA = Asm.getSymbolData(SA);
+  const MCSymbolData &DataB = Asm.getSymbolData(SB);
+
+  return IsSymbolRefDifferenceFullyResolvedImpl(Asm, DataA,
+                                                *DataB.getFragment(),
+                                                InSet,
+                                                false);
+}
+
+bool
+MCObjectWriter::IsSymbolRefDifferenceFullyResolvedImpl(const MCAssembler &Asm,
+                                                      const MCSymbolData &DataA,
+                                                      const MCFragment &FB,
+                                                      bool InSet,
+                                                      bool IsPCRel) const {
+  const MCSection &SecA = DataA.getSymbol().AliasedSymbol().getSection();
+  const MCSection &SecB = FB.getParent()->getSection();
+  // On ELF and COFF  A - B is absolute if A and B are in the same section.
+  return &SecA == &SecB;
+}