[DWARF5] Start emitting DW_AT_dwo_name when -gdwarf-5 is specified.

[merge_guards_bot]

Build result: pass - 60606 tests passed, 0 failed and 726 were skipped.

Log files: console-log.txt, CMakeCache.txt

[probinson]

Address the inline comments and LGTM.

llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp

866

This should be moved down under the 'if' so it's in the same scope as the only use.

1110

This should be moved down under the 'if' so it's in the same scope as the only uses.

[SouraVX]

Thank you Paul, for reviewing this. I've addressed your comments in this revision.

[probinson]

Yep LGTM.

clang/test/CodeGen/split-debug-output.c

 // REQUIRES: x86-registered-target
-// RUN: %clang_cc1 -triple x86_64-unknown-linux -debug-info-kind=limited -split-dwarf-file foo.dwo -split-dwarf-output %t -emit-obj -o - %s | llvm-dwarfdump -debug-info - | FileCheck %s
-// RUN: llvm-dwarfdump -debug-info %t | FileCheck %s
+// RUN: %clang_cc1 -triple x86_64-unknown-linux -debug-info-kind=limited -dwarf-version=4 -split-dwarf-file foo.dwo -split-dwarf-output %t -emit-obj -o - %s | llvm-dwarfdump -debug-info - | FileCheck --check-prefix=DWARFv4 %s
+// RUN: llvm-dwarfdump -debug-info %t | FileCheck --check-prefix=DWARFv4 %s
+
+// RUN: %clang_cc1 -triple x86_64-unknown-linux -debug-info-kind=limited -dwarf-version=5 -split-dwarf-file foo.dwo -split-dwarf-output %t -emit-obj -o - %s | llvm-dwarfdump -debug-info - | FileCheck --check-prefix=DWARFv5 %s
+// RUN: llvm-dwarfdump -debug-info %t | FileCheck --check-prefix=DWARFv5 %s
 
 int f() { return 0; }
 
-// CHECK: DW_AT_GNU_dwo_name ("foo.dwo")
+// DWARFv4: DW_AT_GNU_dwo_name ("foo.dwo")
+// DWARFv5: DW_AT_dwo_name ("foo.dwo")

clang/test/CodeGen/thinlto-split-dwarf.c

 // REQUIRES: x86-registered-target
 
 // RUN: %clang_cc1 -debug-info-kind=limited -triple x86_64-unknown-linux-gnu \
 // RUN:   -flto=thin -emit-llvm-bc \
 // RUN:   -o %t.o %s
 
 // RUN: llvm-lto2 run -thinlto-distributed-indexes %t.o \
 // RUN:   -o %t2.index \
 // RUN:   -r=%t.o,main,px
 
 // RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu \
 // RUN:   -emit-obj -fthinlto-index=%t.o.thinlto.bc \
 // RUN:   -o %t.native.o -split-dwarf-file %t.file.dwo \
 // RUN:   -split-dwarf-output %t.output.dwo -x ir %t.o
 
-// RUN: llvm-dwarfdump %t.native.o | FileCheck --check-prefix=O %s
-// RUN: llvm-dwarfdump %t.output.dwo | FileCheck --check-prefix=DWO %s
+// RUN: llvm-dwarfdump %t.native.o | FileCheck --check-prefix=DWARFv4-O %s
+// RUN: llvm-dwarfdump %t.output.dwo | FileCheck --check-prefix=DWARFv4-DWO %s
 
-// O: DW_AT_GNU_dwo_name ("{{.*}}.file.dwo")
-// O-NOT: DW_TAG_subprogram
-// DWO: DW_TAG_subprogram
+// DWARFv4-O: DW_AT_GNU_dwo_name ("{{.*}}.file.dwo")
+// DWARFv4-O-NOT: DW_TAG_subprogram
+// DWARFv4-DWO: DW_TAG_subprogram
+
+// RUN: %clang_cc1 -debug-info-kind=limited -dwarf-version=5 -triple x86_64-unknown-linux-gnu \
+// RUN:   -flto=thin -emit-llvm-bc \
+// RUN:   -o %t.o %s
+
+// RUN: llvm-lto2 run -thinlto-distributed-indexes %t.o \
+// RUN:   -o %t2.index \
+// RUN:   -r=%t.o,main,px
+
+// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu \
+// RUN:   -emit-obj -fthinlto-index=%t.o.thinlto.bc \
+// RUN:   -o %t.native.o -dwarf-version=5 -split-dwarf-file %t.file.dwo \
+// RUN:   -split-dwarf-output %t.output.dwo -x ir %t.o
+
+// RUN: llvm-dwarfdump %t.native.o | FileCheck --check-prefix=DWARFv5-O %s
+// RUN: llvm-dwarfdump %t.output.dwo | FileCheck --check-prefix=DWARFv5-DWO %s
+
+// DWARFv5-O: DW_AT_dwo_name ("{{.*}}.file.dwo")
+// DWARFv5-O-NOT: DW_TAG_subprogram
+// DWARFv5-DWO: DW_TAG_subprogram
 
 int main() {}

llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp

if (useAppleExtensionAttributes()) {
 
     if (unsigned RVer = DIUnit->getRuntimeVersion())
       NewCU.addUInt(Die, dwarf::DW_AT_APPLE_major_runtime_vers,
                     dwarf::DW_FORM_data1, RVer);
   }
 
   if (DIUnit->getDWOId()) {
     // This CU is either a clang module DWO or a skeleton CU.
+    dwarf::Attribute attrDWOName = getDwarfVersion() >= 5
+                                       ? dwarf::DW_AT_dwo_name
+                                       : dwarf::DW_AT_GNU_dwo_name;
     NewCU.addUInt(Die, dwarf::DW_AT_GNU_dwo_id, dwarf::DW_FORM_data8,
                   DIUnit->getDWOId());
     if (!DIUnit->getSplitDebugFilename().empty())
       // This is a prefabricated skeleton CU.
-      NewCU.addString(Die, dwarf::DW_AT_GNU_dwo_name,
-                      DIUnit->getSplitDebugFilename());
+      NewCU.addString(Die, attrDWOName, DIUnit->getSplitDebugFilename());
   }
 }
 // Create new DwarfCompileUnit for the given metadata node with tag
 // DW_TAG_compile_unit.
 DwarfCompileUnit &
 DwarfDebug::getOrCreateDwarfCompileUnit(const DICompileUnit *DIUnit) {
   if (auto *CU = CUMap.lookup(DIUnit))
     return *CU;
if (TheCU.getCUNode()->isDebugDirectivesOnly())
       continue;
     // Emit DW_AT_containing_type attribute to connect types with their
     // vtable holding type.
     TheCU.constructContainingTypeDIEs();
 
     // Add CU specific attributes if we need to add any.
     // If we're splitting the dwarf out now that we've got the entire
     // CU then add the dwo id to it.
+    dwarf::Attribute attrDWOName = getDwarfVersion() >= 5
+                                       ? dwarf::DW_AT_dwo_name
+                                       : dwarf::DW_AT_GNU_dwo_name;
     auto *SkCU = TheCU.getSkeleton();
 
     bool HasSplitUnit = SkCU && !TheCU.getUnitDie().children().empty();
 
     if (HasSplitUnit) {
       finishUnitAttributes(TheCU.getCUNode(), TheCU);
-      TheCU.addString(TheCU.getUnitDie(), dwarf::DW_AT_GNU_dwo_name,
+      TheCU.addString(TheCU.getUnitDie(), attrDWOName,
                       Asm->TM.Options.MCOptions.SplitDwarfFile);
-      SkCU->addString(SkCU->getUnitDie(), dwarf::DW_AT_GNU_dwo_name,
+      SkCU->addString(SkCU->getUnitDie(), attrDWOName,
                       Asm->TM.Options.MCOptions.SplitDwarfFile);
       // Emit a unique identifier for this CU.
       uint64_t ID =
           DIEHash(Asm).computeCUSignature(DWOName, TheCU.getUnitDie());
       if (getDwarfVersion() >= 5) {
         TheCU.setDWOId(ID);
         SkCU->setDWOId(ID);
       } else {

llvm/lib/DebugInfo/DWARF/DWARFUnit.cpp

 bool DWARFUnit::parseDWO() {
   if (IsDWO)
     return false;
   if (DWO.get())
     return false;
   DWARFDie UnitDie = getUnitDIE();
   if (!UnitDie)
     return false;
-  auto DWOFileName = dwarf::toString(UnitDie.find(DW_AT_GNU_dwo_name));
+  auto DWOFileName = getVersion() >= 5
+                         ? dwarf::toString(UnitDie.find(DW_AT_dwo_name))
+                         : dwarf::toString(UnitDie.find(DW_AT_GNU_dwo_name));
   if (!DWOFileName)
     return false;
   auto CompilationDir = dwarf::toString(UnitDie.find(DW_AT_comp_dir));
   SmallString<16> AbsolutePath;
   if (sys::path::is_relative(*DWOFileName) && CompilationDir &&
       *CompilationDir) {
     sys::path::append(AbsolutePath, *CompilationDir);
   }

llvm/test/DebugInfo/X86/debug_addr.ll

 ; DWARF4-NEXT: 0x00000010
 ; DWARF4-NEXT: ]
 
 ; DWARF5: .debug_info contents:
 ; DWARF5: Compile Unit:{{.*}}version = 0x0005
 ; DWARF5-NOT: Compile Unit
 ; DWARF5: DW_TAG_skeleton_unit
 ; DWARF5-NOT: DW_TAG_{{.*}}
-; DWARF5: DW_AT_GNU_dwo_name{{.*}}test.dwo
+; DWARF5: DW_AT_dwo_name{{.*}}test.dwo
 ; DWARF5: DW_AT_addr_base{{.*}}0x00000008
 ; DWARF5: DW_AT_low_pc [DW_FORM_addrx] (indexed (00000000) address = 0x0000000000000000 ".text")
 ; DWARF5: .debug_addr contents:
 ; DWARF5-NEXT: 0x00000000: Addr Section: length = 0x0000000c, version = 0x0005, addr_size = 0x04, seg_size = 0x00
 ; DWARF5-NEXT: Addrs: [
 ; DWARF5-NEXT: 0x00000000
 ; DWARF5-NEXT: 0x00000010
 ; DWARF5-NEXT: ]

llvm/test/DebugInfo/X86/string-offsets-table.ll

 ;
 ; SPLIT:      .debug_info contents:
 ; SPLIT-NEXT: 0x00000000: Compile Unit:{{.*}}DW_UT_skeleton
 ; SPLIT-NOT:  contents:
 ; SPLIT:      DW_TAG_skeleton_unit
 ; SPLIT-NOT:  {{DW_TAG|contents:}}
 ; SPLIT:      DW_AT_str_offsets_base [DW_FORM_sec_offset] (0x00000008)
 ; SPLIT:      DW_AT_comp_dir [DW_FORM_strx1] (indexed (00000000) string = "/home/test")
-; SPLIT:      DW_AT_GNU_dwo_name [DW_FORM_strx1] (indexed (00000001) string = "foo.dwo")
+; SPLIT:      DW_AT_dwo_name [DW_FORM_strx1] (indexed (00000001) string = "foo.dwo")
 
 ; Check for the split CU in .debug_info.dwo.
 ; SPLIT:      .debug_info.dwo contents:
 ; SPLIT-NEXT: 0x00000000: Compile Unit:{{.*}}DW_UT_split_compile
 ; SPLIT-NOT:  contents:
 ; SPLIT:      DW_TAG_compile_unit
 ;
 ; Check that a couple of indexed strings are displayed correctly and that