3 files changed, 107 insertions, 3 deletions
diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp b/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
index f638087b50f..81eb0c2aa9e 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
@@ -440,11 +440,11 @@ void DwarfCompileUnit::addScopeRangeList(DIE &ScopeDIE,
   // FIXME: For DWARF v5, do not generate the DW_AT_ranges attribute under
   // fission until we support the forms using the .debug_addr section
   // (DW_RLE_startx_endx etc.).
-  if (isDwoUnit())
+  if (DD->getDwarfVersion() >= 5)
+    addUInt(ScopeDIE, dwarf::DW_AT_ranges, dwarf::DW_FORM_rnglistx, Index);
+  else if (isDwoUnit())
     addSectionDelta(ScopeDIE, dwarf::DW_AT_ranges, List.getSym(),
                     RangeSectionSym);
-  else if (DD->getDwarfVersion() >= 5)
-    addUInt(ScopeDIE, dwarf::DW_AT_ranges, dwarf::DW_FORM_rnglistx, Index);
   else
     addSectionLabel(ScopeDIE, dwarf::DW_AT_ranges, List.getSym(),
                     RangeSectionSym);
diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
index e3805bf72b2..3d842e70138 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
@@ -953,6 +953,7 @@ void DwarfDebug::endModule() {
     emitDebugInfoDWO();
     emitDebugAbbrevDWO();
     emitDebugLineDWO();
+    emitDebugRangesDWO();
   }
 
   emitDebugAddr();
@@ -2297,6 +2298,31 @@ void DwarfDebug::emitDebugRanges() {
   emitDebugRangesImpl(*this, Asm, Holder, TableEnd);
 }
 
+void DwarfDebug::emitDebugRangesDWO() {
+  assert(useSplitDwarf());
+
+  if (CUMap.empty())
+    return;
+
+  const auto &Holder = InfoHolder;
+
+  if (Holder.getRangeLists().empty())
+    return;
+
+  assert(getDwarfVersion() >= 5);
+  assert(useRangesSection());
+  assert(llvm::none_of(CUMap, [](const decltype(CUMap)::value_type &Pair) {
+    return Pair.second->getCUNode()->isDebugDirectivesOnly();
+  }));
+
+  // Start the dwarf ranges section.
+  Asm->OutStreamer->SwitchSection(
+      Asm->getObjFileLowering().getDwarfRnglistsDWOSection());
+  MCSymbol *TableEnd = emitRnglistsTableHeader(Asm, Holder);
+
+  emitDebugRangesImpl(*this, Asm, Holder, TableEnd);
+}
+
 void DwarfDebug::handleMacroNodes(DIMacroNodeArray Nodes, DwarfCompileUnit &U) {
   for (auto *MN : Nodes) {
     if (auto *M = dyn_cast<DIMacro>(MN))
diff --git a/llvm/test/DebugInfo/X86/split-dwarf-v5-ranges.ll b/llvm/test/DebugInfo/X86/split-dwarf-v5-ranges.ll
new file mode 100644
index 00000000000..4404d5c3639
--- /dev/null
+++ b/llvm/test/DebugInfo/X86/split-dwarf-v5-ranges.ll
@@ -0,0 +1,78 @@
+; RUN: llc -split-dwarf-file=foo.dwo -mtriple=x86_64-unknown-linux-gnu -filetype=obj < %s \
+; RUN: 	    | llvm-dwarfdump -v -debug-info -debug-rnglists - | FileCheck %s
+
+; CHECK: .debug_info contents:
+; CHECK: .debug_info.dwo contents:
+; CHECK: DW_AT_ranges [DW_FORM_rnglistx] (indexed (0x0) rangelist = 0x00000004
+; CHECK:          [0x0000000000000000, 0x000000000000000b) "x"
+; CHECK:          [0x000000000000000d, 0x0000000000000012) "x")
+
+; CHECK: .debug_rnglists.dwo contents:
+; CHECK: 0x00000000: range list header: length = 0x00000015, version = 0x0005, addr_size = 0x08, seg_size = 0x00, offset_entry_count = 0x00000001
+; CHECK: offsets: [
+; CHECK: 0x00000004 => 0x00000010
+; CHECK: ]
+; CHECK: ranges:
+; CHECK: 0x00000010: [DW_RLE_base_addressx]:  0x0000000000000002
+; CHECK: 0x00000012: [DW_RLE_offset_pair  ]:  0x0000000000000000, 0x000000000000000b => [0x0000000000000001, 0x000000000000000c)
+; CHECK: 0x00000015: [DW_RLE_offset_pair  ]:  0x000000000000000d, 0x0000000000000012 => [0x000000000000000e, 0x0000000000000013)
+; CHECK: 0x00000018: [DW_RLE_end_of_list  ]
+
+; Function Attrs: noinline optnone uwtable
+define dso_local void @_Z2f3v() !dbg !7 {
+entry:
+  %x = alloca i32, align 4
+  call void @llvm.dbg.declare(metadata i32* %x, metadata !10, metadata !DIExpression()), !dbg !13
+  %call = call i32 @_Z2f2v(), !dbg !14
+  store i32 %call, i32* %x, align 4, !dbg !13
+  %0 = load i32, i32* %x, align 4, !dbg !13
+  %tobool = icmp ne i32 %0, 0, !dbg !13
+  br i1 %tobool, label %if.then, label %if.end, !dbg !15
+
+if.then:                                          ; preds = %entry
+  call void @_Z2f1v(), !dbg !16
+  br label %if.end, !dbg !18
+
+if.end:                                           ; preds = %if.then, %entry
+  ret void, !dbg !19
+}
+
+; Function Attrs: nounwind readnone speculatable
+declare void @llvm.dbg.declare(metadata, metadata, metadata)
+
+declare dso_local i32 @_Z2f2v()
+
+declare dso_local void @_Z2f1v()
+
+; Function Attrs: noinline nounwind optnone uwtable
+define dso_local void @_Z2f4v() #3 section "x" !dbg !20 {
+entry:
+  ret void, !dbg !21
+}
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!3, !4, !5}
+!llvm.ident = !{!6}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !1, producer: "clang version 8.0.0 (trunk 344806) (llvm/trunk 344835)", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, nameTableKind: GNU)
+!1 = !DIFile(filename: "ranges.cpp", directory: "/usr/local/google/home/blaikie/dev/scratch", checksumkind: CSK_MD5, checksum: "a1e825b91fba21d696f05eb06d440aa3")
+!2 = !{}
+!3 = !{i32 2, !"Dwarf Version", i32 5}
+!4 = !{i32 2, !"Debug Info Version", i32 3}
+!5 = !{i32 1, !"wchar_size", i32 4}
+!6 = !{!"clang version 8.0.0 (trunk 344806) (llvm/trunk 344835)"}
+!7 = distinct !DISubprogram(name: "f3", linkageName: "_Z2f3v", scope: !1, file: !1, line: 3, type: !8, isLocal: false, isDefinition: true, scopeLine: 3, flags: DIFlagPrototyped, isOptimized: false, unit: !0, retainedNodes: !2)
+!8 = !DISubroutineType(types: !9)
+!9 = !{null}
+!10 = !DILocalVariable(name: "x", scope: !11, file: !1, line: 4, type: !12)
+!11 = distinct !DILexicalBlock(scope: !7, file: !1, line: 4, column: 11)
+!12 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+!13 = !DILocation(line: 4, column: 11, scope: !11)
+!14 = !DILocation(line: 4, column: 15, scope: !11)
+!15 = !DILocation(line: 4, column: 11, scope: !7)
+!16 = !DILocation(line: 5, column: 5, scope: !17)
+!17 = distinct !DILexicalBlock(scope: !11, file: !1, line: 4, column: 21)
+!18 = !DILocation(line: 6, column: 3, scope: !17)
+!19 = !DILocation(line: 7, column: 1, scope: !7)
+!20 = distinct !DISubprogram(name: "f4", linkageName: "_Z2f4v", scope: !1, file: !1, line: 8, type: !8, isLocal: false, isDefinition: true, scopeLine: 8, flags: DIFlagPrototyped, isOptimized: false, unit: !0, retainedNodes: !2)
+!21 = !DILocation(line: 8, column: 42, scope: !20)