MC/ObjectWriter: Add a new IsSymbolRefDifferenceFullyResolved target format specific hook.

 - Currently just has stub implementations for Mach-O, ELF, and COFF.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122037 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 11 insertions, 0 deletions

diff --git a/include/llvm/MC/MCObjectWriter.h b/include/llvm/MC/MCObjectWriter.h
index bae3368..60625b4 100644
--- a/include/llvm/MC/MCObjectWriter.h
+++ b/include/llvm/MC/MCObjectWriter.h
@@ -20,6 +20,7 @@ class MCAsmLayout;
 class MCAssembler;
 class MCFixup;
 class MCFragment;
+class MCSymbolRefExpr;
 class MCValue;
 class raw_ostream;
 
@@ -77,6 +78,16 @@ public:
                                 const MCFixup &Fixup, MCValue Target,
                                 uint64_t &FixedValue) = 0;
 
+  /// \brief Check whether the difference (A - B) between two symbol
+  /// references is fully resolved.
+  ///
+  /// Clients are not required to answer precisely and may conservatively return
+  /// false, even when a difference is fully resolved.
+  virtual bool
+  IsSymbolRefDifferenceFullyResolved(const MCAssembler &Asm,
+                                     const MCSymbolRefExpr *A,
+                                     const MCSymbolRefExpr *B) const = 0;
+
   /// Check if a fixup is fully resolved.
   ///
   /// This routine is used by the assembler to let the file format decide