[mach-o] create __unwind_info section on x86_64

This is a minimally useful pass to construct the __unwind_info section in a
final object from the various __compact_unwind inputs. Currently it doesn't
produce any compressed pages, only works for x86_64 and will fail if any
function ends up without __compact_unwind.

rdar://problem/18208653

llvm-svn: 218703

1 files changed, 15 insertions, 0 deletions

diff --git a/lld/lib/ReaderWriter/MachO/ArchHandler.h b/lld/lib/ReaderWriter/MachO/ArchHandler.h
index 9118535085c..df063167699 100644
--- a/lld/lib/ReaderWriter/MachO/ArchHandler.h
+++ b/lld/lib/ReaderWriter/MachO/ArchHandler.h
@@ -53,6 +53,20 @@ public:
   /// Used by GOTPass to update GOT References
   virtual void updateReferenceToGOT(const Reference *, bool targetIsNowGOT) {}
 
+  /// Does this architecture make use of __unwind_info sections for exception
+  /// handling? If so, it will need a separate pass to create them.
+  virtual bool needsCompactUnwind() = 0;
+
+  /// Returns the kind of reference to use to synthesize a 32-bit image-offset
+  /// value, used in the __unwind_info section.
+  virtual Reference::KindValue imageOffsetKind() = 0;
+
+  /// Returns the kind of reference to use to synthesize a 32-bit image-offset
+  /// indirect value. Used for personality functions in the __unwind_info
+  /// section.
+  virtual Reference::KindValue imageOffsetKindIndirect() = 0;
+
+
   /// Used by normalizedFromAtoms() to know where to generated rebasing and 
   /// binding info in final executables.
   virtual bool isPointer(const Reference &) = 0;
@@ -126,6 +140,7 @@ public:
   /// Copy raw content then apply all fixup References on an Atom.
   virtual void generateAtomContent(const DefinedAtom &atom, bool relocatable,
                                    FindAddressForAtom findAddress,
+                                   uint64_t imageBaseAddress,
                                    uint8_t *atomContentBuffer) = 0;
 
   /// Used in -r mode to convert a Reference to a mach-o relocation.