Index: clang/lib/Driver/ToolChains/Clang.cpp
===================================================================
--- clang/lib/Driver/ToolChains/Clang.cpp
+++ clang/lib/Driver/ToolChains/Clang.cpp
@@ -3539,7 +3539,7 @@
 
   bool SplitDWARFInlining =
       Args.hasFlag(options::OPT_fsplit_dwarf_inlining,
-                   options::OPT_fno_split_dwarf_inlining, true);
+                   options::OPT_fno_split_dwarf_inlining, false);
 
   Args.ClaimAllArgs(options::OPT_g_Group);
 
Index: clang/test/Driver/split-debug.c
===================================================================
--- clang/test/Driver/split-debug.c
+++ clang/test/Driver/split-debug.c
@@ -79,7 +79,7 @@
 // CHECK-SPLIT-WITH-NOINL: "-debug-info-kind=limited"
 // CHECK-SPLIT-WITH-NOINL: "-split-dwarf-output"
 
-// RUN: %clang -target x86_64-unknown-linux-gnu -gsplit-dwarf -gmlt -S -### %s 2> %t
+// RUN: %clang -target x86_64-unknown-linux-gnu -gsplit-dwarf -gmlt -fsplit-dwarf-inlining -S -### %s 2> %t 
 // RUN: FileCheck -check-prefix=CHECK-GMLT-OVER-SPLIT < %t %s
 //
 // CHECK-GMLT-OVER-SPLIT: "-debug-info-kind=line-tables-only"
Index: llvm/lib/DebugInfo/DWARF/DWARFVerifier.cpp
===================================================================
--- llvm/lib/DebugInfo/DWARF/DWARFVerifier.cpp
+++ llvm/lib/DebugInfo/DWARF/DWARFVerifier.cpp
@@ -196,6 +196,14 @@
     NumUnitErrors++;
   }
 
+  //  According to DWARF Debugging Information Format Version 5,
+  //  3.1.2 Skeleton Compilation Unit Entries:
+  //  "A skeleton compilation unit has no children."
+  if (Die.getTag() == dwarf::DW_TAG_skeleton_unit && Die.hasChildren()) {
+    error() << "Skeleton compilation unit has children.\n";
+    NumUnitErrors++;
+  }
+
   DieRangeInfo RI;
   NumUnitErrors += verifyDieRanges(Die, RI);
 
Index: llvm/test/DebugInfo/skeleton-unit-verify.ll
===================================================================
--- /dev/null
+++ llvm/test/DebugInfo/skeleton-unit-verify.ll
@@ -0,0 +1,86 @@
+; RUN: llc %s -mtriple=x86_64-linux -filetype=obj -split-dwarf-cross-cu-references --split-dwarf-file=test.dwo -O3 -o %t 
+; RUN: llvm-dwarfdump --verify %t | FileCheck %s
+; RUN: sed 's/splitDebugInlining: false/splitDebugInlining: true/' < %s > %t2
+; RUN: llc %t2 -mtriple=x86_64-linux -filetype=obj -split-dwarf-cross-cu-references --split-dwarf-file=test.dwo -O3 -o %t1 
+; RUN: not llvm-dwarfdump --verify %t1 | FileCheck --check-prefix=CHECK-SINL %s
+
+; Hand-reduced from this example, test.cpp:
+;
+;int foo ( int p1 ) {
+;    return p1 + 10;
+;}
+;
+;int bar ( int p1 ) {
+;    return foo(p1);
+;}
+;
+;int main ( void ) {
+;    return bar(100);
+;}
+;
+; clang++ -O3 -g -gdwarf-5 test.cpp -gno-column-info
+
+; CHECK: No errors.
+; CHECK-SINL: error: Skeleton compilation unit has children.
+; CHECK-SINL: Errors detected. 
+
+; ModuleID = 'test.cpp'
+source_filename = "test.cpp"
+target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+; Function Attrs: norecurse nounwind readnone uwtable
+define dso_local i32 @_Z3fooi(i32 %p1) local_unnamed_addr #0 !dbg !7 {
+entry:
+  call void @llvm.dbg.value(metadata i32 %p1, metadata !12, metadata !DIExpression()), !dbg !13
+  %add = add nsw i32 %p1, 10, !dbg !14
+  ret i32 %add, !dbg !14
+}
+; Function Attrs: norecurse nounwind readnone uwtable
+define dso_local i32 @_Z3bari(i32 %p1) local_unnamed_addr #0 !dbg !15 {
+entry:
+  call void @llvm.dbg.value(metadata i32 %p1, metadata !17, metadata !DIExpression()), !dbg !18
+  call void @llvm.dbg.value(metadata i32 %p1, metadata !12, metadata !DIExpression()), !dbg !19
+  %add.i = add nsw i32 %p1, 10, !dbg !21
+  ret i32 %add.i, !dbg !22
+}
+; Function Attrs: norecurse nounwind readnone uwtable
+define dso_local i32 @main() local_unnamed_addr #0 !dbg !23 {
+entry:
+  ret i32 110, !dbg !26
+}
+; Function Attrs: nounwind readnone speculatable willreturn
+declare void @llvm.dbg.value(metadata, metadata, metadata) #0
+
+attributes #0 = { nounwind readnone speculatable willreturn }
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!3, !4, !5}
+!llvm.ident = !{!6}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus_14, file: !1, producer: "clang version 10.0.0", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, splitDebugInlining: false, nameTableKind: None)
+!1 = !DIFile(filename: "test.cpp", directory: "test-split-dwarf", checksumkind: CSK_MD5, checksum: "189325d7ad5cd481bc7a631dac6345be")
+!2 = !{}
+!3 = !{i32 7, !"Dwarf Version", i32 5}
+!4 = !{i32 2, !"Debug Info Version", i32 3}
+!5 = !{i32 1, !"wchar_size", i32 4}
+!6 = !{!"clang version 10.0.0"}
+!7 = distinct !DISubprogram(name: "foo", linkageName: "_Z3fooi", scope: !1, file: !1, line: 2, type: !8, scopeLine: 2, flags: DIFlagPrototyped | DIFlagAllCallsDescribed, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0, retainedNodes: !11)
+!8 = !DISubroutineType(types: !9)
+!9 = !{!10, !10}
+!10 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+!11 = !{!12}
+!12 = !DILocalVariable(name: "p1", arg: 1, scope: !7, file: !1, line: 2, type: !10)
+!13 = !DILocation(line: 0, scope: !7)
+!14 = !DILocation(line: 3, scope: !7)
+!15 = distinct !DISubprogram(name: "bar", linkageName: "_Z3bari", scope: !1, file: !1, line: 6, type: !8, scopeLine: 6, flags: DIFlagPrototyped | DIFlagAllCallsDescribed, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0, retainedNodes: !16)
+!16 = !{!17}
+!17 = !DILocalVariable(name: "p1", arg: 1, scope: !15, file: !1, line: 6, type: !10)
+!18 = !DILocation(line: 0, scope: !15)
+!19 = !DILocation(line: 0, scope: !7, inlinedAt: !20)
+!20 = distinct !DILocation(line: 7, scope: !15)
+!21 = !DILocation(line: 3, scope: !7, inlinedAt: !20)
+!22 = !DILocation(line: 7, scope: !15)
+!23 = distinct !DISubprogram(name: "main", scope: !1, file: !1, line: 10, type: !24, scopeLine: 10, flags: DIFlagPrototyped | DIFlagAllCallsDescribed, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0, retainedNodes: !2)
+!24 = !DISubroutineType(types: !25)
+!25 = !{!10}
+!26 = !DILocation(line: 11, scope: !23)