[llvm-dsymutil] Add support for __swift_ast MachO DWARF section

Summary:
Xcode's dsymutil emits a __swift_ast DWARF section, which is required for debugging,
and which contains a byte-for-byte dump of the swiftmodule file.
Add this feature to llvm-dsymutil.

Tested with `gobjdump --dwarf=info -s`, by verifying that the contents of
`__DWARF.__swift_ast` match between Xcode's dsymutil and llvm-dsymutil
(Xcode's dwarfdump and llvm-dwarfdump don't currently recognize the
__swift_ast section).

Reviewers: aprantl, friss

Subscribers: llvm-commits, JDevlieghere

Differential Revision: https://reviews.llvm.org/D38504

llvm-svn: 315014

1 files changed, 6 insertions, 2 deletions

diff --git a/llvm/tools/dsymutil/DebugMap.h b/llvm/tools/dsymutil/DebugMap.h
index eab0cb0a800..0b564149488 100644
--- a/llvm/tools/dsymutil/DebugMap.h
+++ b/llvm/tools/dsymutil/DebugMap.h
@@ -94,7 +94,8 @@ public:
   /// debug map.
   DebugMapObject &
   addDebugMapObject(StringRef ObjectFilePath,
-                    sys::TimePoint<std::chrono::seconds> Timestamp);
+                    sys::TimePoint<std::chrono::seconds> Timestamp,
+                    uint8_t Type);
 
   const Triple &getTriple() const { return BinaryTriple; }
 
@@ -154,6 +155,8 @@ public:
     return Timestamp;
   }
 
+  uint8_t getType() const { return Type; }
+
   iterator_range<StringMap<SymbolMapping>::const_iterator> symbols() const {
     return make_range(Symbols.begin(), Symbols.end());
   }
@@ -166,12 +169,13 @@ private:
   friend class DebugMap;
   /// DebugMapObjects can only be constructed by the owning DebugMap.
   DebugMapObject(StringRef ObjectFilename,
-                 sys::TimePoint<std::chrono::seconds> Timestamp);
+                 sys::TimePoint<std::chrono::seconds> Timestamp, uint8_t Type);
 
   std::string Filename;
   sys::TimePoint<std::chrono::seconds> Timestamp;
   StringMap<SymbolMapping> Symbols;
   DenseMap<uint64_t, DebugMapEntry *> AddressToMapping;
+  uint8_t Type;
 
   /// For YAMLIO support.
   ///@{