Revert r337981: it breaks the debuginfo-tests

This commit caused a regression in the debuginfo-tests:

FAIL: debuginfo-tests :: apple-accel.cpp (40748 of 46595)
llvm-svn: 337997

1 files changed, 47 insertions, 34 deletions

diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
index caf266f6870..f1e61b488a2 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
@@ -820,10 +820,6 @@ void DwarfDebug::finalizeModuleInfo() {
       U.attachRangesOrLowHighPC(U.getUnitDie(), TheCU.takeRanges());
     }
 
-    if (getDwarfVersion() >= 5 && !useSplitDwarf() &&
-        !U.getRangeLists().empty())
-      U.addRnglistsBase();
-
     auto *CUNode = cast<DICompileUnit>(P.first);
     // If compile Unit has macros, emit "DW_AT_macro_info" attribute.
     if (CUNode->getMacros())
@@ -2090,10 +2086,23 @@ static void emitRangeList(AsmPrinter *Asm, DwarfCompileUnit *CU,
   }
 }
 
-// Emit the header of a DWARF 5 range list table. Returns the symbol that
-// designates the end of the table for the caller to emit when the table is
-// complete.
-static MCSymbol *emitRnglistsTableHeader(AsmPrinter *Asm, DwarfFile &Holder) {
+void DwarfDebug::emitDebugRnglists() {
+
+  // Don't emit a rangelist table if there are no ranges.
+  if (llvm::all_of(CUMap,
+                   [](const decltype(CUMap)::const_iterator::value_type &Pair) {
+                     DwarfCompileUnit *TheCU = Pair.second;
+                     if (auto *Skel = TheCU->getSkeleton())
+                       TheCU = Skel;
+                     return TheCU->getRangeLists().empty();
+                   }))
+    return;
+
+  assert(getDwarfVersion() >= 5 && "Dwarf version must be 5 or greater");
+  // FIXME: As long as we don't support DW_RLE_base_addrx, we cannot generate
+  // any tables in the .debug_rnglists.dwo section.
+  Asm->OutStreamer->SwitchSection(
+      Asm->getObjFileLowering().getDwarfRnglistsSection());
   // The length is described by a starting label right after the length field
   // and an end label.
   MCSymbol *TableStart = Asm->createTempSymbol("debug_rnglist_table_start");
@@ -2102,52 +2111,56 @@ static MCSymbol *emitRnglistsTableHeader(AsmPrinter *Asm, DwarfFile &Holder) {
   Asm->EmitLabelDifference(TableEnd, TableStart, 4);
   Asm->OutStreamer->EmitLabel(TableStart);
   // Version number (DWARF v5 and later).
-  Asm->emitInt16(Asm->OutStreamer->getContext().getDwarfVersion());
+  Asm->emitInt16(getDwarfVersion());
   // Address size.
   Asm->emitInt8(Asm->MAI->getCodePointerSize());
   // Segment selector size.
   Asm->emitInt8(0);
 
-  MCSymbol *RnglistTableBaseSym = Holder.getRnglistsTableBaseSym();
+  MCSymbol *RnglistTableBaseSym =
+      (useSplitDwarf() ? SkeletonHolder : InfoHolder).getRnglistsTableBaseSym();
 
   // FIXME: Generate the offsets table and use DW_FORM_rnglistx with the
   // DW_AT_ranges attribute. Until then set the number of offsets to 0.
   Asm->emitInt32(0);
   Asm->OutStreamer->EmitLabel(RnglistTableBaseSym);
-  return TableEnd;
+
+  // Emit the individual range lists.
+  for (const auto &I : CUMap) {
+    DwarfCompileUnit *TheCU = I.second;
+    if (auto *Skel = TheCU->getSkeleton())
+      TheCU = Skel;
+    for (const RangeSpanList &List : TheCU->getRangeLists())
+      emitRangeList(Asm, TheCU, List);
+  }
+
+  Asm->OutStreamer->EmitLabel(TableEnd);
 }
 
-/// Emit address ranges into the .debug_ranges section or into the DWARF v5
-/// .debug_rnglists section.
+/// Emit address ranges into the .debug_ranges section or DWARF v5 rangelists
+/// into the .debug_rnglists section.
 void DwarfDebug::emitDebugRanges() {
   if (CUMap.empty())
     return;
 
-  auto NoRangesPresent = [this]() {
-    return llvm::all_of(
-        CUMap, [](const decltype(CUMap)::const_iterator::value_type &Pair) {
-          return Pair.second->getRangeLists().empty();
-        });
-  };
-
   if (!useRangesSection()) {
-    assert(NoRangesPresent() && "No debug ranges expected.");
+    assert(llvm::all_of(
+               CUMap,
+               [](const decltype(CUMap)::const_iterator::value_type &Pair) {
+                 return Pair.second->getRangeLists().empty();
+               }) &&
+           "No debug ranges expected.");
     return;
   }
 
-  if (NoRangesPresent())
+  if (getDwarfVersion() >= 5) {
+    emitDebugRnglists();
     return;
+  }
 
   // Start the dwarf ranges section.
-  MCSymbol *TableEnd = nullptr;
-  if (getDwarfVersion() >= 5) {
-    Asm->OutStreamer->SwitchSection(
-        Asm->getObjFileLowering().getDwarfRnglistsSection());
-    TableEnd = emitRnglistsTableHeader(Asm, useSplitDwarf() ? SkeletonHolder
-                                                            : InfoHolder);
-  } else
-    Asm->OutStreamer->SwitchSection(
-        Asm->getObjFileLowering().getDwarfRangesSection());
+  Asm->OutStreamer->SwitchSection(
+      Asm->getObjFileLowering().getDwarfRangesSection());
 
   // Grab the specific ranges for the compile units in the module.
   for (const auto &I : CUMap) {
@@ -2160,9 +2173,6 @@ void DwarfDebug::emitDebugRanges() {
     for (const RangeSpanList &List : TheCU->getRangeLists())
       emitRangeList(Asm, TheCU, List);
   }
-
-  if (TableEnd)
-    Asm->OutStreamer->EmitLabel(TableEnd);
 }
 
 void DwarfDebug::handleMacroNodes(DIMacroNodeArray Nodes, DwarfCompileUnit &U) {
@@ -2238,6 +2248,9 @@ void DwarfDebug::initSkeletonUnit(const DwarfUnit &U, DIE &Die,
   SkeletonHolder.addUnit(std::move(NewU));
 }
 
+// This DIE has the following attributes: DW_AT_comp_dir, DW_AT_stmt_list,
+// DW_AT_low_pc, DW_AT_high_pc, DW_AT_ranges, DW_AT_dwo_name, DW_AT_dwo_id,
+// DW_AT_addr_base, DW_AT_ranges_base or DW_AT_rnglists_base.
 DwarfCompileUnit &DwarfDebug::constructSkeletonCU(const DwarfCompileUnit &CU) {
 
   auto OwnedUnit = llvm::make_unique<DwarfCompileUnit>(