Reland [DebugInfo] generate btf_tag annotations for DIComposite types

Clang patch D106614 added attribute btf_tag support. This patch
generates btf_tag annotations for DIComposite types.
A field "annotations" is introduced to DIComposite, and the
annotations are represented as an DINodeArray, similar to
DIComposite elements. The following example illustrates
how annotations are encoded in IR:
  distinct !DICompositeType(..., annotations: !10)
  !10 = !{!11, !12}
  !11 = !{!"btf_tag", !"a"}
  !12 = !{!"btf_tag", !"b"}
Each btf_tag annotation is represented as a 2D array of
meta strings. Each record may have more than one
btf_tag annotations, as in the above example.

Reland with additional fixes for llvm/unittests/IR/DebugTypeODRUniquingTest.cpp.

Differential Revision: https://reviews.llvm.org/D106615

2 files changed, 8 insertions, 3 deletions

diff --git a/llvm/lib/Bitcode/Reader/MetadataLoader.cpp b/llvm/lib/Bitcode/Reader/MetadataLoader.cpp
index 8493eb7..da6010e 100644
--- a/llvm/lib/Bitcode/Reader/MetadataLoader.cpp
+++ b/llvm/lib/Bitcode/Reader/MetadataLoader.cpp
@@ -1461,7 +1461,7 @@ Error MetadataLoader::MetadataLoaderImpl::parseOneMetadata(
     break;
   }
   case bitc::METADATA_COMPOSITE_TYPE: {
-    if (Record.size() < 16 || Record.size() > 21)
+    if (Record.size() < 16 || Record.size() > 22)
       return error("Invalid record");
 
     // If we have a UUID and this is not a forward declaration, lookup the
@@ -1489,6 +1489,7 @@ Error MetadataLoader::MetadataLoaderImpl::parseOneMetadata(
     Metadata *Associated = nullptr;
     Metadata *Allocated = nullptr;
     Metadata *Rank = nullptr;
+    Metadata *Annotations = nullptr;
     auto *Identifier = getMDString(Record[15]);
     // If this module is being parsed so that it can be ThinLTO imported
     // into another module, composite types only need to be imported
@@ -1520,6 +1521,9 @@ Error MetadataLoader::MetadataLoaderImpl::parseOneMetadata(
       if (Record.size() > 20) {
         Rank = getMDOrNull(Record[20]);
       }
+      if (Record.size() > 21) {
+        Annotations = getMDOrNull(Record[21]);
+      }
     }
     DICompositeType *CT = nullptr;
     if (Identifier)
@@ -1527,7 +1531,7 @@ Error MetadataLoader::MetadataLoaderImpl::parseOneMetadata(
           Context, *Identifier, Tag, Name, File, Line, Scope, BaseType,
           SizeInBits, AlignInBits, OffsetInBits, Flags, Elements, RuntimeLang,
           VTableHolder, TemplateParams, Discriminator, DataLocation, Associated,
-          Allocated, Rank);
+          Allocated, Rank, Annotations);
 
     // Create a node if we didn't get a lazy ODR type.
     if (!CT)
@@ -1536,7 +1540,7 @@ Error MetadataLoader::MetadataLoaderImpl::parseOneMetadata(
                             SizeInBits, AlignInBits, OffsetInBits, Flags,
                             Elements, RuntimeLang, VTableHolder, TemplateParams,
                             Identifier, Discriminator, DataLocation, Associated,
-                            Allocated, Rank));
+                            Allocated, Rank, Annotations));
     if (!IsNotUsedInTypeRef && Identifier)
       MetadataList.addTypeRef(*Identifier, *cast<DICompositeType>(CT));
 
diff --git a/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp b/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp
index ed2c66e..c5d8c55 100644
--- a/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp
+++ b/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp
@@ -1714,6 +1714,7 @@ void ModuleBitcodeWriter::writeDICompositeType(
   Record.push_back(VE.getMetadataOrNullID(N->getRawAssociated()));
   Record.push_back(VE.getMetadataOrNullID(N->getRawAllocated()));
   Record.push_back(VE.getMetadataOrNullID(N->getRawRank()));
+  Record.push_back(VE.getMetadataOrNullID(N->getAnnotations().get()));
 
   Stream.EmitRecord(bitc::METADATA_COMPOSITE_TYPE, Record, Abbrev);
   Record.clear();