Revert r198851, "Prototype of skeleton type units for fission"

It caused undefined behavior. DwarfTypeUnit::Ty might not be initialized properly, I guess.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@198865 91177308-0d34-0410-b5e6-96231b3b80d8

lib/CodeGen/AsmPrinter/DwarfDebug.cpp

@@ -2976,21 +2976,6 @@ DwarfCompileUnit *DwarfDebug::constructSkeletonCU(const DwarfCompileUnit *CU) {
   return NewCU;
 }
 
-// This DIE has the following attributes: DW_AT_comp_dir, DW_AT_dwo_name,
-// DW_AT_addr_base.
-DwarfTypeUnit *DwarfDebug::constructSkeletonTU(const DwarfTypeUnit *TU) {
-
-  DIE *Die = new DIE(dwarf::DW_TAG_type_unit);
-  DwarfTypeUnit *NewTU = new DwarfTypeUnit(
-      TU->getUniqueID(), Die, TU->getCUNode(), Asm, this, &SkeletonHolder);
-  NewTU->setTypeSignature(TU->getTypeSignature());
-  NewTU->initSection(
-      Asm->getObjFileLowering().getDwarfTypesSection(TU->getTypeSignature()));
-
-  initSkeletonUnit(TU, Die, NewTU);
-  return NewTU;
-}
-
 // Emit the .debug_info.dwo section for separated dwarf. This contains the
 // compile units that would normally be in debug_info.
 void DwarfDebug::emitDebugInfoDWO() {
@@ -3033,6 +3018,8 @@ void DwarfDebug::addDwarfTypeUnitType(DICompileUnit CUNode,
     NewTU->addUInt(UnitDie, dwarf::DW_AT_language, dwarf::DW_FORM_data2,
                    CUNode.getLanguage());
 
+    DIE *Die = NewTU->createTypeDIE(CTy);
+
     MD5 Hash;
     Hash.update(Identifier);
     // ... take the least significant 8 bytes and return those. Our MD5
@@ -3042,10 +3029,7 @@ void DwarfDebug::addDwarfTypeUnitType(DICompileUnit CUNode,
     Hash.final(Result);
     uint64_t Signature = *reinterpret_cast<support::ulittle64_t *>(Result + 8);
     NewTU->setTypeSignature(Signature);
-    if (useSplitDwarf())
-      NewTU->setSkeleton(constructSkeletonTU(NewTU));
-
-    NewTU->setType(NewTU->createTypeDIE(CTy));
+    NewTU->setType(Die);
 
     NewTU->initSection(
         useSplitDwarf()

lib/CodeGen/AsmPrinter/DwarfDebug.h

@@ -596,10 +596,6 @@ class DwarfDebug : public AsmPrinterHandler {
   /// section.
   DwarfCompileUnit *constructSkeletonCU(const DwarfCompileUnit *CU);
 
-  /// \brief Construct the split debug info compile unit for the debug info
-  /// section.
-  DwarfTypeUnit *constructSkeletonTU(const DwarfTypeUnit *TU);
-
   /// \brief Emit the debug info dwo section.
   void emitDebugInfoDWO();
 

lib/CodeGen/AsmPrinter/DwarfUnit.cpp

@@ -1987,9 +1987,7 @@ void DwarfTypeUnit::emitHeader(const MCSection *ASection,
   Asm->OutStreamer.AddComment("Type Signature");
   Asm->OutStreamer.EmitIntValue(TypeSignature, sizeof(TypeSignature));
   Asm->OutStreamer.AddComment("Type DIE Offset");
-  // In a skeleton type unit there is no type DIE so emit a zero offset.
-  Asm->OutStreamer.EmitIntValue(Ty ? Ty->getOffset() : 0,
-                                sizeof(Ty->getOffset()));
+  Asm->OutStreamer.EmitIntValue(Ty->getOffset(), sizeof(Ty->getOffset()));
 }
 
 void DwarfTypeUnit::initSection(const MCSection *Section) {

lib/MC/MCObjectFileInfo.cpp

@@ -726,9 +726,8 @@ const MCSection *MCObjectFileInfo::getDwarfTypesSection(uint64_t Hash) const {
 
 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));
+  return Ctx->getELFSection(".debug_types.dwo", ELF::SHT_GROUP, 0,
+                            SectionKind::getMetadata(), 0, utostr(Hash));
 }
 
 void MCObjectFileInfo::InitEHFrameSection() {

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

@@ -1,10 +1,7 @@
 ; REQUIRES: object-emission
 
 ; 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: 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-dwarfdump %t | FileCheck %s
 
 ; Generated from:
 ; struct bar {};
@@ -46,8 +43,7 @@
 
 ; wombat wom;
 
-; SINGLE-LABEL: .debug_info contents:
-; FISSION-LABEL: .debug_info.dwo contents:
+; CHECK-LABEL: .debug_info contents:
 ; CHECK: Compile Unit: length = [[CU_SIZE:[0-9a-f]+]]
 
 ; CHECK: DW_TAG_structure_type
@@ -57,54 +53,40 @@
 
 ; Ensure the CU-local type 'walrus' is not placed in a type unit.
 ; CHECK: DW_TAG_structure_type
-; CHECK-NEXT: DW_AT_name{{.*}}"walrus"
+; CHECK-NEXT: debug_str{{.*}}"walrus"
 ; CHECK-NEXT: DW_AT_byte_size
 ; CHECK-NEXT: DW_AT_decl_file
 ; CHECK-NEXT: DW_AT_decl_line
 
-; FISSION-LABEL: .debug_types contents:
-; FISSION-NOT: type_signature
-; FISSION-LABEL: type_signature = 0x1d02f3be30cc5688
-; FISSION: DW_TAG_type_unit
-; FISSION: DW_AT_GNU_dwo_name{{.*}}"bar.dwo"
-; FISSION: DW_AT_comp_dir{{.*}}"/tmp/dbginfo"
-; FISSION-NOT: type_signature
-; FISSION-LABEL: type_signature = 0xb04af47397402e77
-; FISSION-NOT: type_signature
-; FISSION-LABEL: type_signature = 0xfd756cee88f8a118
-; FISSION-NOT: type_signature
-; FISSION-LABEL: type_signature = 0xe94f6d3843e62d6b
-
-; SINGLE-LABEL: .debug_types contents:
-; FISSION-LABEL: .debug_types.dwo contents:
+; CHECK-LABEL: .debug_types contents:
 
 ; Check that we generate a hash for bar and the value.
 ; CHECK-NOT: type_signature
 ; CHECK-LABEL: type_signature = 0x1d02f3be30cc5688
 ; CHECK: DW_TAG_structure_type
-; CHECK-NEXT: DW_AT_name{{.*}}"bar"
+; CHECK-NEXT: debug_str{{.*}}"bar"
 
 
 ; Check that we generate a hash for fluffy and the value.
 ; CHECK-NOT: type_signature
 ; CHECK-LABEL: type_signature = 0xb04af47397402e77
 ; CHECK-NOT: DW_AT_GNU_odr_signature [DW_FORM_data8]   (0x9a0124d5a0c21c52)
 ; CHECK: DW_TAG_namespace
-; CHECK-NEXT: DW_AT_name{{.*}}"echidna"
+; CHECK-NEXT: debug_str{{.*}}"echidna"
 ; CHECK: DW_TAG_namespace
-; CHECK-NEXT: DW_AT_name{{.*}}"capybara"
+; CHECK-NEXT: debug_str{{.*}}"capybara"
 ; CHECK: DW_TAG_namespace
-; CHECK-NEXT: DW_AT_name{{.*}}"mongoose"
+; CHECK-NEXT: debug_str{{.*}}"mongoose"
 ; CHECK: DW_TAG_class_type
-; CHECK-NEXT: DW_AT_name{{.*}}"fluffy"
+; CHECK-NEXT: debug_str{{.*}}"fluffy"
 
 ; Check that we generate a hash for wombat and the value, but not for the
 ; anonymous type contained within.
 ; CHECK-NOT: type_signature
 ; CHECK-LABEL: type_signature = 0xfd756cee88f8a118
 ; CHECK-NOT: DW_AT_GNU_odr_signature [DW_FORM_data8] (0x685bcc220141e9d7)
 ; CHECK: DW_TAG_structure_type
-; CHECK-NEXT: DW_AT_name{{.*}}"wombat"
+; CHECK-NEXT: debug_str{{.*}}"wombat"
 
 ; CHECK-NOT: type_signature
 ; CHECK-LABEL: type_signature = 0xe94f6d3843e62d6b
@@ -118,7 +100,7 @@
 ; CHECK-NOT: DW_AT_name
 ; CHECK-NOT: DW_AT_GNU_odr_signature
 ; CHECK: DW_TAG_member
-; CHECK-NEXT: DW_AT_name{{.*}}"a"
+; CHECK-NEXT: debug_str{{.*}}"a"
 
 ; Use the unit size as a rough hash/identifier for the unit we're dealing with
 ; it happens to be unambiguous at the moment, but it's hardly ideal.
@@ -128,21 +110,17 @@
 ; CHECK-NEXT: Offset Name
 ; CHECK-NEXT: "walrus"
 ; Type unit for 'bar'
-; SINGLE-NEXT: unit_size = 0x00000023
-; FISSION-NEXT: unit_size = 0x00000024
+; CHECK-NEXT: unit_size = 0x00000023
 ; CHECK-NEXT: Offset Name
 ; CHECK-NEXT: "bar"
-; SINGLE-NEXT: unit_size = 0x0000005d
-; FISSION-NEXT: unit_size = 0x00000024
+; CHECK-NEXT: unit_size = 0x0000005d
 ; CHECK-NEXT: Offset Name
 ; CHECK-NEXT: "int"
 ; CHECK-NEXT: "echidna::capybara::mongoose::fluffy"
-; SINGLE-NEXT: unit_size = 0x0000003a
-; FISSION-NEXT: unit_size = 0x00000024
+; CHECK-NEXT: unit_size = 0x0000003a
 ; CHECK-NEXT: Offset Name
 ; CHECK-NEXT: "wombat"
-; SINGLE-NEXT: unit_size = 0x0000004b
-; FISSION-NEXT: unit_size = 0x00000024
+; CHECK-NEXT: unit_size = 0x0000004b
 ; CHECK-NEXT: Offset Name
 ; CHECK-NEXT: "int"
 
@@ -201,7 +179,7 @@ attributes #1 = { nounwind readnone }
 !llvm.module.flags = !{!42, !54}
 !llvm.ident = !{!43}
 
-!0 = metadata !{i32 786449, metadata !1, i32 4, metadata !"clang version 3.4 ", i1 false, metadata !"", i32 0, metadata !2, metadata !3, metadata !20, metadata !37, metadata !2, metadata !"bar.dwo"} ; [ DW_TAG_compile_unit ] [/tmp/dbginfo/bar.cpp] [DW_LANG_C_plus_plus]
+!0 = metadata !{i32 786449, metadata !1, i32 4, metadata !"clang version 3.4 ", i1 false, metadata !"", i32 0, metadata !2, metadata !3, metadata !20, metadata !37, metadata !2, metadata !""} ; [ DW_TAG_compile_unit ] [/tmp/dbginfo/bar.cpp] [DW_LANG_C_plus_plus]
 !1 = metadata !{metadata !"bar.cpp", metadata !"/tmp/dbginfo"}
 !2 = metadata !{i32 0}
 !3 = metadata !{metadata !4, metadata !5, metadata !13, metadata !16}