Debug info: Fix the storage size of zero-size types.

This removes an obsolete workaround that prevented zero-sized types from
being emitted with the correct byte size.

Author: adrian-prantl

lib/IRGen/IRGenDebugInfo.cpp

@@ -1260,12 +1260,6 @@ llvm::DIType *IRGenDebugInfo::createType(DebugTypeInfo DbgTy,
   // to emit the (target!) size of the underlying basic type.
   uint64_t SizeOfByte = CI.getTargetInfo().getCharWidth();
   uint64_t SizeInBits = DbgTy.size.getValue() * SizeOfByte;
-  // Prefer the actual storage size over the DbgTy.
-  if (DbgTy.StorageType && DbgTy.StorageType->isSized()) {
-    uint64_t Storage = IGM.DataLayout.getTypeSizeInBits(DbgTy.StorageType);
-    if (Storage)
-      SizeInBits = Storage;
-  }
   uint64_t AlignInBits = DbgTy.align.getValue() * SizeOfByte;
   unsigned Encoding = 0;
   unsigned Flags = 0;

test/DebugInfo/nostorage.swift

@@ -10,7 +10,10 @@ public class Foo {
       // CHECK1: call void @llvm.dbg.value(metadata i{{.*}} 0,
       // CHECK1-SAME:                      metadata ![[TYPE:.*]], metadata
       // CHECK1: ![[TYPE]] = !DILocalVariable(name: "type",
-      // CHECK1-SAME:                         line: [[@LINE+1]],
+      // CHECK1-SAME:                         line: [[@LINE+4]],
+      // CHECK1-SAME:                         type: ![[FOO:[0-9]+]]
+      // CHECK1: ![[FOO]] = !DICompositeType(tag: DW_TAG_structure_type,
+      // CHECK1-SAME:                        line: [[@LINE+1]], align: 8, flags:
             let type = self.dynamicType
             used(type)
         }()