Add ApplePropertyString dump helper to Dwarf.{h|cpp}.

[dblaikie]

Sure, looks fine.

(this sort of thing can probably go in with usage - so it's tested/exercised/executed - rather than just dead code. It's a tricky balance in terms of commit granularity, though usually a change like this is isolated enough from the (presumably) dwarf dumping code that'll be using it that it doesn't complicate the review)

[friss]

Closed by commit rL219442 (authored by @friss).

llvm/trunk/include/llvm/Support/Dwarf.h

 /// MacinfoString - Return the string for the specified macinfo type encodings.
 ///
 const char *MacinfoString(unsigned Encoding);
 
 /// CallFrameString - Return the string for the specified call frame instruction
 /// encodings.
 const char *CallFrameString(unsigned Encoding);
 
+/// ApplePropertyString - Return the string for the specified Apple
+/// property bit. This function is meant to return the symbolic name
+/// for 1 bit of the DW_AT_APPLE_property attribute, not for the whole attribute.
+const char *ApplePropertyString(unsigned);
+
 // Constants for the DWARF5 Accelerator Table Proposal
 enum AcceleratorTable {
   // Data layout descriptors.
   DW_ATOM_null = 0u,       // Marker as the end of a list of atoms.
   DW_ATOM_die_offset = 1u, // DIE offset in the debug_info section.
   DW_ATOM_cu_offset = 2u, // Offset of the compile unit header that contains the
                           // item in question.
   DW_ATOM_die_tag = 3u,   // A tag entry.

llvm/trunk/lib/Support/Dwarf.cpp

const char *llvm::dwarf::CallFrameString(unsigned Encoding) {
   case DW_CFA_GNU_window_save:           return "DW_CFA_GNU_window_save";
   case DW_CFA_GNU_args_size:             return "DW_CFA_GNU_args_size";
   case DW_CFA_lo_user:                   return "DW_CFA_lo_user";
   case DW_CFA_hi_user:                   return "DW_CFA_hi_user";
   }
   return nullptr;
 }
 
+/// ApplePropertyString - Return the string for the specified Apple
+/// property bit. This function is meant to return the symbolic name
+/// for 1 bit of the DW_AT_APPLE_property attribute, not for the whole attribute.
+const char *llvm::dwarf::ApplePropertyString(unsigned Prop) {
+  switch (Prop) {
+  case DW_APPLE_PROPERTY_readonly:
+    return "DW_APPLE_PROPERTY_readonly";
+  case DW_APPLE_PROPERTY_getter:
+    return "DW_APPLE_PROPERTY_getter";
+  case DW_APPLE_PROPERTY_assign:
+    return "DW_APPLE_PROPERTY_assign";
+  case DW_APPLE_PROPERTY_readwrite:
+    return "DW_APPLE_PROPERTY_readwrite";
+  case DW_APPLE_PROPERTY_retain:
+    return "DW_APPLE_PROPERTY_retain";
+  case DW_APPLE_PROPERTY_copy:
+    return "DW_APPLE_PROPERTY_copy";
+  case DW_APPLE_PROPERTY_nonatomic:
+    return "DW_APPLE_PROPERTY_nonatomic";
+  case DW_APPLE_PROPERTY_setter:
+    return "DW_APPLE_PROPERTY_setter";
+  case DW_APPLE_PROPERTY_atomic:
+    return "DW_APPLE_PROPERTY_atomic";
+  case DW_APPLE_PROPERTY_weak:
+    return "DW_APPLE_PROPERTY_weak";
+  case DW_APPLE_PROPERTY_strong:
+    return "DW_APPLE_PROPERTY_strong";
+  case DW_APPLE_PROPERTY_unsafe_unretained:
+    return "DW_APPLE_PROPERTY_unsafe_unretained";
+  }
+  return nullptr;
+}
+
 const char *llvm::dwarf::AtomTypeString(unsigned AT) {
   switch (AT) {
   case dwarf::DW_ATOM_null:
     return "DW_ATOM_null";
   case dwarf::DW_ATOM_die_offset:
     return "DW_ATOM_die_offset";
   case DW_ATOM_cu_offset:
     return "DW_ATOM_cu_offset";