Reapply: "DebugInfo: Emit only one kind of accelerated access/name table""

Originally committed in r358931
Reverted in r358997

Seems this change made Apple accelerator tables miss names (because
names started respecting the CU NameTableKind GNU & assuming that
shouldn't produce accelerated names too), which is never correct (apple
accelerator tables don't have separators or CU lists - if present, they
must describe all names in all CUs).

Original Description:
Currently to opt in to debug_names in DWARFv5, the IR must contain
'nameTableKind: Default' which also enables debug_pubnames.

Instead, only allow one of {debug_names, apple_names, debug_pubnames,
debug_gnu_pubnames}.

nameTableKind: Default gives debug_names in DWARFv5 and greater,
debug_pubnames in v4 and earlier - and apple_names when tuning for lldb
on MachO.
nameTableKind: GNU always gives gnu_pubnames

llvm-svn: 359026

5 files changed, 96 insertions, 6 deletions

diff --git a/llvm/lib/CodeGen/AsmPrinter/AccelTable.cpp b/llvm/lib/CodeGen/AsmPrinter/AccelTable.cpp
index c4eef7ad722..b5617f46ddd 100644
--- a/llvm/lib/CodeGen/AsmPrinter/AccelTable.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/AccelTable.cpp
@@ -555,8 +555,8 @@ void llvm::emitDWARF5AccelTable(
   SmallVector<unsigned, 1> CUIndex(CUs.size());
   int Count = 0;
   for (const auto &CU : enumerate(CUs)) {
-    if (CU.value()->getCUNode()->getNameTableKind() ==
-        DICompileUnit::DebugNameTableKind::None)
+    if (CU.value()->getCUNode()->getNameTableKind() !=
+        DICompileUnit::DebugNameTableKind::Default)
       continue;
     CUIndex[CU.index()] = Count++;
     assert(CU.index() == CU.value()->getUniqueID());
diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp b/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
index c1e8ffec75a..0a06dfdae06 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
@@ -1036,7 +1036,9 @@ bool DwarfCompileUnit::hasDwarfPubSections() const {
     return true;
   case DICompileUnit::DebugNameTableKind::Default:
     return DD->tuneForGDB() && !includeMinimalInlineScopes() &&
-           !CUNode->isDebugDirectivesOnly();
+           !CUNode->isDebugDirectivesOnly() &&
+           DD->getAccelTableKind() != AccelTableKind::Apple &&
+           DD->getDwarfVersion() < 5;
   }
   llvm_unreachable("Unhandled DICompileUnit::DebugNameTableKind enum");
 }
diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
index b18ee18d7a3..816dd5b66e1 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
@@ -2761,7 +2761,7 @@ void DwarfDebug::addAccelNameImpl(const DICompileUnit &CU,
     return;
 
   if (getAccelTableKind() != AccelTableKind::Apple &&
-      CU.getNameTableKind() == DICompileUnit::DebugNameTableKind::None)
+      CU.getNameTableKind() != DICompileUnit::DebugNameTableKind::Default)
     return;
 
   DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
diff --git a/llvm/test/DebugInfo/X86/accel-tables.ll b/llvm/test/DebugInfo/X86/accel-tables.ll
index 813b66f1aeb..1aef33c33e7 100644
--- a/llvm/test/DebugInfo/X86/accel-tables.ll
+++ b/llvm/test/DebugInfo/X86/accel-tables.ll
@@ -4,11 +4,11 @@
 ; RUN: llc -mtriple=x86_64-apple-darwin12 -filetype=obj < %s \
 ; RUN:   | llvm-readobj -sections - | FileCheck --check-prefix=APPLE %s
 ; RUN: llc -mtriple=x86_64-apple-darwin12 -filetype=obj -debugger-tune=gdb < %s \
-; RUN:   | llvm-readobj -sections - | FileCheck --check-prefix=NONE %s
+; RUN:   | llvm-readobj -sections - | FileCheck --check-prefix=PUB %s
 
 ; Linux does has debug_names tables only if we explicitly tune for lldb
 ; RUN: llc -mtriple=x86_64-pc-linux -filetype=obj < %s \
-; RUN:   | llvm-readobj -sections - | FileCheck --check-prefix=NONE %s
+; RUN:   | llvm-readobj -sections - | FileCheck --check-prefix=PUB %s
 ; RUN: llc -mtriple=x86_64-pc-linux -filetype=obj -debugger-tune=lldb < %s \
 ; RUN:   | llvm-readobj -sections - | FileCheck --check-prefix=DEBUG_NAMES %s
 
@@ -23,15 +23,25 @@
 ; RUN:   | llvm-readobj -sections - | FileCheck --check-prefix=APPLE %s
 
 ; APPLE-NOT: debug_names
+; APPLE-NOT: debug{{.*}}pub
 ; APPLE: apple_names
 ; APPLE-NOT: debug_names
+; APPLE-NOT: debug{{.*}}pub
+
+; PUB-NOT: apple_names
+; PUB-NOT: debug_names
+; PUB: pubnames
+; PUB-NOT: apple_names
+; PUB-NOT: debug_names
 
 ; NONE-NOT: apple_names
 ; NONE-NOT: debug_names
 
 ; DEBUG_NAMES-NOT: apple_names
+; DEBUG_NAMES-NOT: pubnames
 ; DEBUG_NAMES: debug_names
 ; DEBUG_NAMES-NOT: apple_names
+; DEBUG_NAMES-NOT: pubnames
 
 @var = thread_local global i32 0, align 4, !dbg !0
 
diff --git a/llvm/test/DebugInfo/X86/gnu-names.ll b/llvm/test/DebugInfo/X86/gnu-names.ll
new file mode 100644
index 00000000000..502d15d75ca
--- /dev/null
+++ b/llvm/test/DebugInfo/X86/gnu-names.ll
@@ -0,0 +1,78 @@
+; Verify the emission of accelerator tables for various targets for the DWARF<=4 case
+
+; Darwin has the apple tables unless we specifically tune for gdb
+; RUN: llc -mtriple=x86_64-apple-darwin12 -filetype=obj < %s > %t
+; RUN: llvm-readobj -sections %t | FileCheck --check-prefix=APPLE %s
+; RUN: llvm-dwarfdump -apple-names %t | FileCheck --check-prefix=APPLE-NAMES %s
+; RUN: llc -mtriple=x86_64-apple-darwin12 -filetype=obj -debugger-tune=gdb < %s \
+; RUN:   | llvm-readobj -sections - | FileCheck --check-prefix=GNU %s
+
+; Linux does has debug_names tables only if we explicitly tune for lldb
+; RUN: llc -mtriple=x86_64-pc-linux -filetype=obj < %s \
+; RUN:   | llvm-readobj -sections - | FileCheck --check-prefix=GNU %s
+; RUN: llc -mtriple=x86_64-pc-linux -filetype=obj -debugger-tune=lldb < %s \
+; RUN:   | llvm-readobj -sections - | FileCheck --check-prefix=GNU %s
+
+; No accelerator tables if type units are enabled, as DWARF v4 type units are
+; not compatible with accelerator tables.
+; RUN: llc -mtriple=x86_64-pc-linux -filetype=obj -generate-type-units -debugger-tune=lldb < %s \
+; RUN:   | llvm-readobj -sections - | FileCheck --check-prefix=NONE %s
+
+; Debug types are ignored for non-ELF targets which means it shouldn't affect
+; accelerator table generation.
+; RUN: llc -mtriple=x86_64-apple-darwin12 -generate-type-units -filetype=obj < %s \
+; RUN:   | llvm-readobj -sections - | FileCheck --check-prefix=APPLE %s
+
+; APPLE-NOT: debug_names
+; APPLE-NOT: debug{{.*}}pub
+; APPLE: apple_names
+; APPLE-NOT: debug_names
+; APPLE: debug{{.*}}pub
+
+; APPLE-NAMES: Hashes count: 3
+
+; GNU-NOT: apple_names
+; GNU-NOT: debug_names
+; GNU: gnu_pub
+; GNU-NOT: apple_names
+; GNU-NOT: debug_names
+
+; NONE-NOT: apple_names
+; NONE-NOT: debug_names
+; NONE: debug_gnu_pub
+
+@var = thread_local global i32 0, align 4, !dbg !0
+
+; Function Attrs: norecurse nounwind readnone uwtable
+define void @_Z3funv() local_unnamed_addr #0 !dbg !11 {
+  ret void, !dbg !14
+}
+
+; Function Attrs: norecurse uwtable
+define weak_odr hidden i32* @_ZTW3var() local_unnamed_addr #1 {
+  ret i32* @var
+}
+
+attributes #0 = { norecurse nounwind readnone uwtable }
+attributes #1 = { norecurse uwtable }
+
+!llvm.dbg.cu = !{!2}
+!llvm.module.flags = !{!7, !8, !9}
+!llvm.ident = !{!10}
+
+!0 = !DIGlobalVariableExpression(var: !1, expr: !DIExpression())
+!1 = distinct !DIGlobalVariable(name: "var", scope: !2, file: !3, line: 1, type: !6, isLocal: false, isDefinition: true)
+!2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "clang version 7.0.0 (trunk 322268) (llvm/trunk 322267)", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !4, globals: !5, nameTableKind: GNU)
+!3 = !DIFile(filename: "debugger-tune.cpp", directory: "/tmp")
+!4 = !{}
+!5 = !{!0}
+!6 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+!7 = !{i32 2, !"Dwarf Version", i32 4}
+!8 = !{i32 2, !"Debug Info Version", i32 3}
+!9 = !{i32 1, !"wchar_size", i32 4}
+!10 = !{!"clang version 7.0.0 (trunk 322268) (llvm/trunk 322267)"}
+!11 = distinct !DISubprogram(name: "fun", linkageName: "_Z3funv", scope: !3, file: !3, line: 2, type: !12, isLocal: false, isDefinition: true, scopeLine: 2, flags: DIFlagPrototyped, isOptimized: true, unit: !2, retainedNodes: !4)
+!12 = !DISubroutineType(types: !13)
+!13 = !{null}
+!14 = !DILocation(line: 2, column: 13, scope: !11)
+