Revert "DebugInfo: Don't put fission type units in comdat sections."

This reverts commit r208930, r208933, and r208975.

It seems not all fission consumers are ready to handle this behavior.
Reverting until tools are brought up to spec.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@209338 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/MC/MCObjectFileInfo.h

@@ -122,7 +122,6 @@ class MCObjectFileInfo {
 
   /// These are used for the Fission separate debug information files.
   const MCSection *DwarfInfoDWOSection;
-  const MCSection *DwarfTypesDWOSection;
   const MCSection *DwarfAbbrevDWOSection;
   const MCSection *DwarfStrDWOSection;
   const MCSection *DwarfLineDWOSection;
@@ -271,9 +270,7 @@ class MCObjectFileInfo {
     return DwarfInfoDWOSection;
   }
   const MCSection *getDwarfTypesSection(uint64_t Hash) const;
-  const MCSection *getDwarfTypesDWOSection() const {
-    return DwarfTypesDWOSection;
-  }
+  const MCSection *getDwarfTypesDWOSection(uint64_t Hash) const;
   const MCSection *getDwarfAbbrevDWOSection() const {
     return DwarfAbbrevDWOSection;
   }

lib/CodeGen/AsmPrinter/DwarfDebug.cpp

@@ -1588,12 +1588,9 @@ void DwarfDebug::emitSectionLabels() {
   // Dwarf sections base addresses.
   DwarfInfoSectionSym =
       emitSectionSym(Asm, TLOF.getDwarfInfoSection(), "section_info");
-  if (useSplitDwarf()) {
+  if (useSplitDwarf())
     DwarfInfoDWOSectionSym =
         emitSectionSym(Asm, TLOF.getDwarfInfoDWOSection(), "section_info_dwo");
-    DwarfTypesDWOSectionSym =
-        emitSectionSym(Asm, TLOF.getDwarfTypesDWOSection(), "section_types_dwo");
-  }
   DwarfAbbrevSectionSym =
       emitSectionSym(Asm, TLOF.getDwarfAbbrevSection(), "section_abbrev");
   if (useSplitDwarf())
@@ -2357,9 +2354,9 @@ void DwarfDebug::addDwarfTypeUnitType(DwarfCompileUnit &CU,
   bool TopLevelType = TypeUnitsUnderConstruction.empty();
   AddrPool.resetUsedFlag();
 
-  auto OwnedUnit = make_unique<DwarfTypeUnit>(
-      InfoHolder.getUnits().size() + TypeUnitsUnderConstruction.size(), CU, Asm,
-      this, &InfoHolder, getDwoLineTable(CU));
+  auto OwnedUnit =
+      make_unique<DwarfTypeUnit>(InfoHolder.getUnits().size(), CU, Asm, this,
+                                 &InfoHolder, getDwoLineTable(CU));
   DwarfTypeUnit &NewTU = *OwnedUnit;
   DIE &UnitDie = NewTU.getUnitDie();
   TU = &NewTU;
@@ -2372,14 +2369,13 @@ void DwarfDebug::addDwarfTypeUnitType(DwarfCompileUnit &CU,
   uint64_t Signature = makeTypeSignature(Identifier);
   NewTU.setTypeSignature(Signature);
 
-  if (useSplitDwarf())
-    NewTU.initSection(Asm->getObjFileLowering().getDwarfTypesDWOSection(),
-                      DwarfTypesDWOSectionSym);
-  else {
+  if (!useSplitDwarf())
     CU.applyStmtList(UnitDie);
-    NewTU.initSection(
-        Asm->getObjFileLowering().getDwarfTypesSection(Signature));
-  }
+
+  NewTU.initSection(
+      useSplitDwarf()
+          ? Asm->getObjFileLowering().getDwarfTypesDWOSection(Signature)
+          : Asm->getObjFileLowering().getDwarfTypesSection(Signature));
 
   NewTU.setType(NewTU.createTypeDIE(CTy));
 

lib/CodeGen/AsmPrinter/DwarfDebug.h

@@ -253,7 +253,6 @@ class DwarfDebug : public AsmPrinterHandler {
   MCSymbol *DwarfDebugLocSectionSym, *DwarfLineSectionSym, *DwarfAddrSectionSym;
   MCSymbol *FunctionBeginSym, *FunctionEndSym;
   MCSymbol *DwarfInfoDWOSectionSym, *DwarfAbbrevDWOSectionSym;
-  MCSymbol *DwarfTypesDWOSectionSym;
   MCSymbol *DwarfStrDWOSectionSym;
   MCSymbol *DwarfGnuPubNamesSectionSym, *DwarfGnuPubTypesSectionSym;
 

lib/CodeGen/AsmPrinter/DwarfUnit.h

@@ -577,10 +577,6 @@ class DwarfTypeUnit : public DwarfUnit {
            sizeof(uint32_t);                               // Type DIE Offset
   }
   void initSection(const MCSection *Section);
-  // Bring in the base function (taking two args, including the section symbol)
-  // for use when building DWO type units (they don't go in unique comdat
-  // sections)
-  using DwarfUnit::initSection;
   DwarfCompileUnit &getCU() override { return CU; }
 
 protected:

lib/MC/MCObjectFileInfo.cpp

@@ -537,9 +537,6 @@ void MCObjectFileInfo::InitELFMCObjectFileInfo(Triple T) {
   DwarfInfoDWOSection =
     Ctx->getELFSection(".debug_info.dwo", ELF::SHT_PROGBITS, 0,
                        SectionKind::getMetadata());
-  DwarfTypesDWOSection =
-    Ctx->getELFSection(".debug_types.dwo", ELF::SHT_PROGBITS, 0,
-                       SectionKind::getMetadata());
   DwarfAbbrevDWOSection =
     Ctx->getELFSection(".debug_abbrev.dwo", ELF::SHT_PROGBITS, 0,
                        SectionKind::getMetadata());
@@ -709,10 +706,6 @@ void MCObjectFileInfo::InitCOFFMCObjectFileInfo(Triple T) {
       Ctx->getCOFFSection(".debug_info.dwo", COFF::IMAGE_SCN_MEM_DISCARDABLE |
                                                 COFF::IMAGE_SCN_MEM_READ,
                           SectionKind::getMetadata());
-  DwarfTypesDWOSection =
-      Ctx->getCOFFSection(".debug_types.dwo", COFF::IMAGE_SCN_MEM_DISCARDABLE |
-                                                  COFF::IMAGE_SCN_MEM_READ,
-                          SectionKind::getMetadata());
   DwarfAbbrevDWOSection =
       Ctx->getCOFFSection(".debug_abbrev.dwo", COFF::IMAGE_SCN_MEM_DISCARDABLE |
                                                   COFF::IMAGE_SCN_MEM_READ,
@@ -814,6 +807,13 @@ const MCSection *MCObjectFileInfo::getDwarfTypesSection(uint64_t Hash) const {
                             SectionKind::getMetadata(), 0, utostr(Hash));
 }
 
+const MCSection *
+MCObjectFileInfo::getDwarfTypesDWOSection(uint64_t Hash) const {
+  return Ctx->getELFSection(".debug_types.dwo", ELF::SHT_PROGBITS,
+                            ELF::SHF_GROUP, SectionKind::getMetadata(), 0,
+                            utostr(Hash));
+}
+
 void MCObjectFileInfo::InitEHFrameSection() {
   if (Env == IsMachO)
     EHFrameSection =

test/DebugInfo/X86/generate-odr-hash.ll

@@ -1,12 +1,10 @@
 ; REQUIRES: object-emission
 
-; RUN: llc < %s -o %t -filetype=obj -O0 -generate-type-units -mtriple=x86_64-unknown-linux-gnu
+; RUN: llc %s -o %t -filetype=obj -O0 -generate-type-units -mtriple=x86_64-unknown-linux-gnu
 ; RUN: llvm-dwarfdump %t | FileCheck --check-prefix=CHECK --check-prefix=SINGLE %s
-; RUN: llvm-readobj -s -t %t | FileCheck --check-prefix=OBJ_COMMON %s
 
-; RUN: llc < %s -split-dwarf=Enable -o %t -filetype=obj -O0 -generate-type-units -mtriple=x86_64-unknown-linux-gnu
+; RUN: llc %s -split-dwarf=Enable -o %t -filetype=obj -O0 -generate-type-units -mtriple=x86_64-unknown-linux-gnu
 ; RUN: llvm-dwarfdump %t | FileCheck --check-prefix=CHECK --check-prefix=FISSION %s
-; RUN: llvm-readobj -s -t %t | FileCheck --check-prefix=OBJ_COMMON --check-prefix=OBJ_FISSION %s
 
 ; Generated from bar.cpp:
 
@@ -163,20 +161,6 @@
 ; CHECK-NEXT: [[FLUFFY]] "echidna::capybara::mongoose::fluffy"
 ; CHECK-NEXT: [[WALRUS]] "walrus"
 
-; Make sure debug_types are in comdat groups. This could be more rigid to check
-; that they're the right comdat groups (each type in a separate comdat group,
-; etc)
-; OBJ_COMMON: Name: .debug_types (
-; OBJ_COMMON-NOT: }
-; OBJ_COMMON: SHF_GROUP
-
-; Fission type units don't go in comdat groups, since their linker is debug
-; aware it's handled using the debug info semantics rather than raw ELF object
-; semantics.
-; OBJ_FISSION: Name: .debug_types.dwo (
-; OBJ_FISSION-NOT: SHF_GROUP
-; OBJ_FISSION: }
-
 %struct.bar = type { i8 }
 %"class.echidna::capybara::mongoose::fluffy" = type { i32, i32 }
 %"struct.<anonymous namespace>::walrus" = type { i8 }