DebugInfo: Do not emit empty CUs

Consistent with GCC and addresses a shortcoming with ThinLTO where many
imported CUs may end up being empty (because the functions imported from
them either ended up not being used (and were then discarded, since
they're imported as available_externally) or optimized away entirely).

Test cases previously testing empty CUs (either intentionally, or
because they didn't need anything more complicated) had a trivial 'int'
or similar basic type added to their retained types list.

This is a first order approximation - a deeper implementation could do
things like:

1) Be more lazy about construction of the CU - for example if two CUs
containing a single identical retained type are linked together, with
this change one of the two CUs will be produced but empty (since a
duplicate type won't be produced).

2) Go further and invert all the CU links the same way the subprogram
link is inverted - keep named CU lists of retained types, macros, etc,
and have those link back to the CU. Then if they're emitted, the CU is
emitted, but never otherwise - this would allow the metadata itself to
be dropped earlier too, though it seems unlikely that's an important
optimization as there shouldn't be many CUs relative to the number of
other entities.

llvm-svn: 304020

diff --git a/llvm/include/llvm/IR/Metadata.h b/llvm/include/llvm/IR/Metadata.h
index 92f701e..3c75326 100644 (file)
--- a/llvm/include/llvm/IR/Metadata.h
+++ b/llvm/include/llvm/IR/Metadata.h
@@ -1223,6 +1223,7 @@ public:
 
   // FIXME: Fix callers and remove condition on N.
   unsigned size() const { return N ? N->getNumOperands() : 0u; }
+  bool empty() const { return N ? N->getNumOperands() == 0 : true; }
   T *operator[](unsigned I) const { return cast_or_null<T>(N->getOperand(I)); }
 
   // FIXME: Fix callers and remove condition on N.

diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
index 3ea4c1c..b6cd82a 100644 (file)
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
@@ -374,7 +374,7 @@ void DwarfDebug::constructAbstractSubprogramScopeDIE(DwarfCompileUnit &SrcCU,
 
   // Find the subprogram's DwarfCompileUnit in the SPMap in case the subprogram
   // was inlined from another compile unit.
-  auto &CU = *CUMap.lookup(SP->getUnit());
+  auto &CU = getOrCreateDwarfCompileUnit(SP->getUnit());
   if (auto *SkelCU = CU.getSkeleton()) {
     (shareAcrossDWOCUs() ? CU : SrcCU)
         .constructAbstractSubprogramScopeDIE(Scope);
@@ -407,7 +407,9 @@ void DwarfDebug::addGnuPubAttributes(DwarfCompileUnit &U, DIE &D) const {
 // Create new DwarfCompileUnit for the given metadata node with tag
 // DW_TAG_compile_unit.
 DwarfCompileUnit &
-DwarfDebug::constructDwarfCompileUnit(const DICompileUnit *DIUnit) {
+DwarfDebug::getOrCreateDwarfCompileUnit(const DICompileUnit *DIUnit) {
+  if (auto *CU = CUMap.lookup(DIUnit))
+    return *CU;
   StringRef FN = DIUnit->getFilename();
   CompilationDir = DIUnit->getDirectory();
 
@@ -540,7 +542,12 @@ void DwarfDebug::beginModule() {
   }
 
   for (DICompileUnit *CUNode : M->debug_compile_units()) {
-    DwarfCompileUnit &CU = constructDwarfCompileUnit(CUNode);
+    if (CUNode->getEnumTypes().empty() && CUNode->getRetainedTypes().empty() &&
+        CUNode->getGlobalVariables().empty() &&
+        CUNode->getImportedEntities().empty() && CUNode->getMacros().empty())
+      continue;
+
+    DwarfCompileUnit &CU = getOrCreateDwarfCompileUnit(CUNode);
     for (auto *IE : CUNode->getImportedEntities())
       CU.addImportedEntity(IE);
 
@@ -587,11 +594,12 @@ void DwarfDebug::finishVariableDefinitions() {
 }
 
 void DwarfDebug::finishSubprogramDefinitions() {
-  for (const DISubprogram *SP : ProcessedSPNodes)
-    if (SP->getUnit()->getEmissionKind() != DICompileUnit::NoDebug)
-      forBothCUs(*CUMap.lookup(SP->getUnit()), [&](DwarfCompileUnit &CU) {
-        CU.finishSubprogramDefinition(SP);
-      });
+  for (const DISubprogram *SP : ProcessedSPNodes) {
+    assert(SP->getUnit()->getEmissionKind() != DICompileUnit::NoDebug);
+    forBothCUs(
+        getOrCreateDwarfCompileUnit(SP->getUnit()),
+        [&](DwarfCompileUnit &CU) { CU.finishSubprogramDefinition(SP); });
+  }
 }
 
 void DwarfDebug::finalizeModuleInfo() {
@@ -1136,12 +1144,10 @@ void DwarfDebug::beginFunctionImpl(const MachineFunction *MF) {
 
   auto *SP = MF->getFunction()->getSubprogram();
   assert(LScopes.empty() || SP == LScopes.getCurrentFunctionScope()->getScopeNode());
-  DwarfCompileUnit *TheCU = CUMap.lookup(SP->getUnit());
-  if (!TheCU) {
-    assert(SP->getUnit()->getEmissionKind() == DICompileUnit::NoDebug &&
-           "DICompileUnit missing from llvm.dbg.cu?");
+  if (SP->getUnit()->getEmissionKind() == DICompileUnit::NoDebug)
     return;
-  }
+
+  DwarfCompileUnit &CU = getOrCreateDwarfCompileUnit(SP->getUnit());
 
   // Set DwarfDwarfCompileUnitID in MCContext to the Compile Unit this function
   // belongs to so that we add to the correct per-cu line table in the
@@ -1150,7 +1156,7 @@ void DwarfDebug::beginFunctionImpl(const MachineFunction *MF) {
     // Use a single line table if we are generating assembly.
     Asm->OutStreamer->getContext().setDwarfCompileUnitID(0);
   else
-    Asm->OutStreamer->getContext().setDwarfCompileUnitID(TheCU->getUniqueID());
+    Asm->OutStreamer->getContext().setDwarfCompileUnitID(CU.getUniqueID());
 
   // Record beginning of function.
   PrologEndLoc = findPrologueEndLoc(MF);
@@ -1546,6 +1552,9 @@ void DwarfDebug::emitDebugLocEntryLocation(const DebugLocStream::Entry &Entry) {
 
 // Emit locations into the debug loc section.
 void DwarfDebug::emitDebugLoc() {
+  if (DebugLocs.getLists().empty())
+    return;
+
   // Start the dwarf loc section.
   Asm->OutStreamer->SwitchSection(
       Asm->getObjFileLowering().getDwarfLocSection());
@@ -1757,6 +1766,9 @@ void DwarfDebug::emitDebugARanges() {
 
 /// Emit address ranges into a debug ranges section.
 void DwarfDebug::emitDebugRanges() {
+  if (CUMap.empty())
+    return;
+
   // Start the dwarf ranges section.
   Asm->OutStreamer->SwitchSection(
       Asm->getObjFileLowering().getDwarfRangesSection());
@@ -1836,6 +1848,9 @@ void DwarfDebug::emitMacroFile(DIMacroFile &F, DwarfCompileUnit &U) {
 
 /// Emit macros into a debug macinfo section.
 void DwarfDebug::emitDebugMacinfo() {
+  if (CUMap.empty())
+    return;
+
   // Start the dwarf macinfo section.
   Asm->OutStreamer->SwitchSection(
       Asm->getObjFileLowering().getDwarfMacinfoSection());

diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h
index 97b96dd..ebfba4c 100644 (file)
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h
@@ -416,7 +416,7 @@ class DwarfDebug : public DebugHandlerBase {
 
   /// Create new DwarfCompileUnit for the given metadata node with tag
   /// DW_TAG_compile_unit.
-  DwarfCompileUnit &constructDwarfCompileUnit(const DICompileUnit *DIUnit);
+  DwarfCompileUnit &getOrCreateDwarfCompileUnit(const DICompileUnit *DIUnit);
 
   /// Construct imported_module or imported_declaration DIE.
   void constructAndAddImportedEntityDIE(DwarfCompileUnit &TheCU,

diff --git a/llvm/test/DebugInfo/Generic/empty.ll b/llvm/test/DebugInfo/Generic/empty.ll
index 4c23300..7991284 100644 (file)
--- a/llvm/test/DebugInfo/Generic/empty.ll
+++ b/llvm/test/DebugInfo/Generic/empty.ll
@@ -15,9 +15,6 @@
 ; CHECK: .debug_pubnames contents:
 ; CHECK-NOT: {{^}}0x
 
-; CHECK: .debug_pubtypes contents:
-; CHECK-NOT: {{^}}0x
-
 ; CHECK: contents:
 
 ; Don't emit DW_AT_addr_base when there are no addresses.
@@ -26,8 +23,10 @@
 !llvm.dbg.cu = !{!0}
 !llvm.module.flags = !{!5}
 
-!0 = distinct !DICompileUnit(language: DW_LANG_C99, producer: "clang version 3.1 (trunk 143523)", isOptimized: true, emissionKind: FullDebug, file: !4, enums: !2, retainedTypes: !2, globals: !2)
+!0 = distinct !DICompileUnit(language: DW_LANG_C99, producer: "clang version 3.1 (trunk 143523)", isOptimized: true, emissionKind: FullDebug, file: !4, enums: !2, retainedTypes: !6, globals: !2)
 !2 = !{}
 !3 = !DIFile(filename: "empty.c", directory: "/home/nlewycky")
 !4 = !DIFile(filename: "empty.c", directory: "/home/nlewycky")
 !5 = !{i32 1, !"Debug Info Version", i32 3}
+!6 = !{!7}
+!7 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)

diff --git a/llvm/test/DebugInfo/Generic/nodebug.ll b/llvm/test/DebugInfo/Generic/nodebug.ll
index 93ed49d..9b0eb9b 100644 (file)
--- a/llvm/test/DebugInfo/Generic/nodebug.ll
+++ b/llvm/test/DebugInfo/Generic/nodebug.ll
@@ -42,7 +42,7 @@ attributes #0 = { uwtable "less-precise-fpmad"="false" "no-frame-pointer-elim"="
 !llvm.module.flags = !{!8, !9}
 !llvm.ident = !{!10}
 
-!0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, producer: "clang version 3.5.0 ", isOptimized: false, emissionKind: FullDebug, file: !1, enums: !2, retainedTypes: !2, globals: !2, imports: !2)
+!0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, producer: "clang version 3.5.0 ", isOptimized: false, emissionKind: FullDebug, file: !1, enums: !2, retainedTypes: !12, globals: !2, imports: !2)
 !1 = !DIFile(filename: "nodebug.cpp", directory: "/tmp/dbginfo")
 !2 = !{}
 !4 = distinct !DISubprogram(name: "f1", linkageName: "_Z2f1v", line: 2, isLocal: false, isDefinition: true, virtualIndex: 6, flags: DIFlagPrototyped, isOptimized: false, unit: !0, scopeLine: 2, file: !1, scope: !5, type: !6, variables: !2)
@@ -53,3 +53,5 @@ attributes #0 = { uwtable "less-precise-fpmad"="false" "no-frame-pointer-elim"="
 !9 = !{i32 2, !"Debug Info Version", i32 3}
 !10 = !{!"clang version 3.5.0 "}
 !11 = !DILocation(line: 3, scope: !4)
+!12 = !{!13}
+!13 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)

diff --git a/llvm/test/DebugInfo/Generic/skeletoncu.ll b/llvm/test/DebugInfo/Generic/skeletoncu.ll
index 6d91afd..b9761b2 100644 (file)
--- a/llvm/test/DebugInfo/Generic/skeletoncu.ll
+++ b/llvm/test/DebugInfo/Generic/skeletoncu.ll
@@ -7,9 +7,11 @@
 !llvm.dbg.cu = !{!0}
 !llvm.module.flags = !{!3, !4}
 
-!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "LLVM", isOptimized: false, runtimeVersion: 2, splitDebugFilename: "my.dwo", emissionKind: FullDebug, enums: !2, retainedTypes: !2, globals: !2, imports: !2, dwoId: 43981)
+!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "LLVM", isOptimized: false, runtimeVersion: 2, splitDebugFilename: "my.dwo", emissionKind: FullDebug, enums: !2, retainedTypes: !5, globals: !2, imports: !2, dwoId: 43981)
 !1 = !DIFile(filename: "<stdin>", directory: "/")
 !2 = !{}
 !3 = !{i32 2, !"Dwarf Version", i32 4}
 !4 = !{i32 2, !"Debug Info Version", i32 3}
+!5 = !{!6}
+!6 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
 

diff --git a/llvm/test/DebugInfo/X86/debug-loc-offset.ll b/llvm/test/DebugInfo/X86/debug-loc-offset.ll
index 8e3e1e9..8f2210e 100644 (file)
--- a/llvm/test/DebugInfo/X86/debug-loc-offset.ll
+++ b/llvm/test/DebugInfo/X86/debug-loc-offset.ll
@@ -35,10 +35,6 @@
 ; CHECK: DW_AT_low_pc
 ; CHECK: DW_AT_high_pc
 
-; CHECK: DW_TAG_compile_unit
-; CHECK: DW_AT_low_pc
-; CHECK: DW_AT_high_pc
-
 ; CHECK: DW_TAG_subprogram
 ; CHECK-NOT: DW_TAG
 ; CHECK: DW_AT_linkage_name [DW_FORM_strp]{{.*}}"_Z3baz1A"
@@ -53,6 +49,10 @@
 ; CHECK: DW_AT_location [DW_FORM_exprloc]
 ; CHECK-NOT: DW_AT_location
 
+; CHECK: DW_TAG_compile_unit
+; CHECK: DW_AT_low_pc
+; CHECK: DW_AT_high_pc
+
 ; CHECK: .debug_loc contents:
 ; CHECK: 0x00000000: Beginning address offset: 0x0000000000000000
 ; CHECK:                Ending address offset: 0x0000000000000017

diff --git a/llvm/test/DebugInfo/X86/debug-macro.ll b/llvm/test/DebugInfo/X86/debug-macro.ll
index 2b3adce..a8b3d4b 100644 (file)
--- a/llvm/test/DebugInfo/X86/debug-macro.ll
+++ b/llvm/test/DebugInfo/X86/debug-macro.ll
@@ -1,40 +1,38 @@
-; RUN: %llc_dwarf -O0 -filetype=obj < %s | llvm-dwarfdump -debug-dump=info - | FileCheck --check-prefix=CHECK-INFO %s
-; RUN: %llc_dwarf -O0 -filetype=obj < %s | llvm-dwarfdump -debug-dump=macro - | FileCheck --check-prefix=CHECK-MACRO %s
-; RUN: %llc_dwarf -O0 -filetype=obj < %s | llvm-dwarfdump -debug-dump=line - | FileCheck --check-prefix=CHECK-LINE %s
+; RUN: %llc_dwarf -O0 -filetype=obj < %s | llvm-dwarfdump - | FileCheck %s
 
 
-; CHECK-INFO: .debug_info contents:
-; CHECK-INFO: DW_TAG_compile_unit
-; CHECK-INFO-NOT: DW_TAG
-; CHECK-INFO:   DW_AT_name {{.*}}"debug-macro.cpp")
-; CHECK-INFO:   DW_AT_macro_info {{.*}}(0x00000000)
-; CHECK-INFO: DW_TAG_compile_unit
-; CHECK-INFO-NOT: DW_TAG
-; CHECK-INFO:   DW_AT_name {{.*}}"debug-macro1.cpp")
-; CHECK-INFO:   DW_AT_macro_info {{.*}}(0x00000044)
-; CHECK-INFO: DW_TAG_compile_unit
-; CHECK-INFO-NOT: DW_TAG
-; CHECK-INFO:   DW_AT_name {{.*}}"debug-macro2.cpp")
-; CHECK-INFO-NOT: DW_AT_macro_info
+; CHECK-LABEL: .debug_info contents:
+; CHECK: DW_TAG_compile_unit
+; CHECK-NOT: DW_TAG
+; CHECK:   DW_AT_name {{.*}}"debug-macro.cpp")
+; CHECK:   DW_AT_macro_info {{.*}}(0x00000000)
+; CHECK: DW_TAG_compile_unit
+; CHECK-NOT: DW_TAG
+; CHECK:   DW_AT_name {{.*}}"debug-macro1.cpp")
+; CHECK:   DW_AT_macro_info {{.*}}(0x00000044)
+; CHECK: DW_TAG_compile_unit
+; CHECK-NOT: DW_TAG
+; CHECK:   DW_AT_name {{.*}}"debug-macro2.cpp")
+; CHECK-NOT: DW_AT_macro_info
 
-; CHECK-MACRO:     .debug_macinfo contents:
-; CHECK-MACRO-NEXT: DW_MACINFO_define - lineno: 0 macro: NameCMD ValueCMD
-; CHECK-MACRO-NEXT: DW_MACINFO_start_file - lineno: 0 filenum: 1
-; CHECK-MACRO-NEXT:   DW_MACINFO_start_file - lineno: 9 filenum: 2
-; CHECK-MACRO-NEXT:     DW_MACINFO_define - lineno: 1 macro: NameDef Value
-; CHECK-MACRO-NEXT:     DW_MACINFO_undef - lineno: 11 macro: NameUndef
-; CHECK-MACRO-NEXT:   DW_MACINFO_end_file
-; CHECK-MACRO-NEXT:   DW_MACINFO_undef - lineno: 10 macro: NameUndef2
-; CHECK-MACRO-NEXT: DW_MACINFO_end_file
-; CHECK-MACRO-NEXT: DW_MACINFO_start_file - lineno: 0 filenum: 1
-; CHECK-MACRO-NEXT: DW_MACINFO_end_file
+; CHECK-LABEL:     .debug_macinfo contents:
+; CHECK-NEXT: DW_MACINFO_define - lineno: 0 macro: NameCMD ValueCMD
+; CHECK-NEXT: DW_MACINFO_start_file - lineno: 0 filenum: 1
+; CHECK-NEXT:   DW_MACINFO_start_file - lineno: 9 filenum: 2
+; CHECK-NEXT:     DW_MACINFO_define - lineno: 1 macro: NameDef Value
+; CHECK-NEXT:     DW_MACINFO_undef - lineno: 11 macro: NameUndef
+; CHECK-NEXT:   DW_MACINFO_end_file
+; CHECK-NEXT:   DW_MACINFO_undef - lineno: 10 macro: NameUndef2
+; CHECK-NEXT: DW_MACINFO_end_file
+; CHECK-NEXT: DW_MACINFO_start_file - lineno: 0 filenum: 1
+; CHECK-NEXT: DW_MACINFO_end_file
 
-; CHECK-LINE: .debug_line contents:
-; CHECK-LINE: Dir  Mod Time   File Len   File Name
-; CHECK-LINE: file_names[  1] {{.*}}debug-macro.cpp
-; CHECK-LINE: file_names[  2] {{.*}}debug-macro.h
-; CHECK-LINE: Dir  Mod Time   File Len   File Name
-; CHECK-LINE: file_names[  1] {{.*}}debug-macro1.cpp
+; CHECK-LABEL: .debug_line contents:
+; CHECK: Dir  Mod Time   File Len   File Name
+; CHECK: file_names[  1] {{.*}}debug-macro.cpp
+; CHECK: file_names[  2] {{.*}}debug-macro.h
+; CHECK: Dir  Mod Time   File Len   File Name
+; CHECK: file_names[  1] {{.*}}debug-macro1.cpp
 
 !llvm.dbg.cu = !{!0, !16, !20}
 !llvm.module.flags = !{!13, !14}
@@ -58,10 +56,14 @@
 !14 = !{i32 1, !"Debug Info Version", i32 3}
 !15 = !{!"clang version 3.5.0 "}
 
-!16 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, producer: "clang version 3.5.0 ", isOptimized: false, emissionKind: FullDebug, file: !17, enums: !2, retainedTypes: !2, globals: !2, imports: !2, macros: !18)
+!16 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, producer: "clang version 3.5.0 ", isOptimized: false, emissionKind: FullDebug, file: !17, enums: !2, retainedTypes: !22, globals: !2, imports: !2, macros: !18)
 !17 = !DIFile(filename: "debug-macro1.cpp", directory: "/")
 !18 = !{!19}
 !19 = !DIMacroFile(line: 0, file: !17, nodes: !2)
 
-!20 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, producer: "clang version 3.5.0 ", isOptimized: false, emissionKind: FullDebug, file: !21, enums: !2, retainedTypes: !2, globals: !2, imports: !2)
+!20 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, producer: "clang version 3.5.0 ", isOptimized: false, emissionKind: FullDebug, file: !21, enums: !2, retainedTypes: !24, globals: !2, imports: !2)
 !21 = !DIFile(filename: "debug-macro2.cpp", directory: "/")
+!22 = !{!23}
+!23 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+!24 = !{!25}
+!25 = !DIBasicType(name: "float", size: 32, encoding: DW_ATE_float)

diff --git a/llvm/test/DebugInfo/X86/empty.ll b/llvm/test/DebugInfo/X86/empty.ll
index a91e0d5..b89af57 100644 (file)
--- a/llvm/test/DebugInfo/X86/empty.ll
+++ b/llvm/test/DebugInfo/X86/empty.ll
@@ -12,20 +12,16 @@
 ; CHECK-NEXT: Offset
 ; CHECK-NEXT: {{^$}}
 
-; CHECK: .debug_pubtypes contents:
-; CHECK-NEXT: length = 0x0000000e
-; CHECK-NEXT: Offset
-; CHECK-NEXT: {{^$}}
-
-
 ; Don't emit DW_AT_addr_base when there are no addresses.
 ; FISSION-NOT: DW_AT_GNU_addr_base [DW_FORM_sec_offset]
 
 !llvm.dbg.cu = !{!0}
 !llvm.module.flags = !{!5}
 
-!0 = distinct !DICompileUnit(language: DW_LANG_C99, producer: "clang version 3.1 (trunk 143523)", isOptimized: true, emissionKind: FullDebug, file: !4, enums: !2, retainedTypes: !2, globals: !2)
+!0 = distinct !DICompileUnit(language: DW_LANG_C99, producer: "clang version 3.1 (trunk 143523)", isOptimized: true, emissionKind: FullDebug, file: !4, enums: !2, retainedTypes: !6, globals: !2)
 !2 = !{}
 !3 = !DIFile(filename: "empty.c", directory: "/home/nlewycky")
 !4 = !DIFile(filename: "empty.c", directory: "/home/nlewycky")
 !5 = !{i32 1, !"Debug Info Version", i32 3}
+!6 = !{!7}
+!7 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)

diff --git a/llvm/test/DebugInfo/X86/fission-hash.ll b/llvm/test/DebugInfo/X86/fission-hash.ll
index 1a5fba2..de9966a 100644 (file)
--- a/llvm/test/DebugInfo/X86/fission-hash.ll
+++ b/llvm/test/DebugInfo/X86/fission-hash.ll
@@ -1,16 +1,18 @@
 ; RUN: llc -split-dwarf-file=foo.dwo -O0 %s -mtriple=x86_64-unknown-linux-gnu -filetype=obj -o %t
 ; RUN: llvm-dwarfdump -debug-dump=all %t | FileCheck %s
 
-; The source is an empty file.
+; The source is an empty file, modified to include/retain an 'int' type, since empty CUs are omitted.
 
-; CHECK: DW_AT_GNU_dwo_id [DW_FORM_data8] (0x0c1e629c9e5ada4f)
-; CHECK: DW_AT_GNU_dwo_id [DW_FORM_data8] (0x0c1e629c9e5ada4f)
+; CHECK: DW_AT_GNU_dwo_id [DW_FORM_data8] (0x50d985146a74bb00)
+; CHECK: DW_AT_GNU_dwo_id [DW_FORM_data8] (0x50d985146a74bb00)
 
 !llvm.dbg.cu = !{!0}
 !llvm.module.flags = !{!3, !4}
 
-!0 = distinct !DICompileUnit(language: DW_LANG_C99, producer: "clang version 3.4 (trunk 188230) (llvm/trunk 188234)", isOptimized: false, splitDebugFilename: "foo.dwo", emissionKind: FullDebug, file: !1, enums: !2, retainedTypes: !2, globals: !2, imports: !2)
+!0 = distinct !DICompileUnit(language: DW_LANG_C99, producer: "clang version 3.4 (trunk 188230) (llvm/trunk 188234)", isOptimized: false, splitDebugFilename: "foo.dwo", emissionKind: FullDebug, file: !1, enums: !2, retainedTypes: !5, globals: !2, imports: !2)
 !1 = !DIFile(filename: "foo.c", directory: "/usr/local/google/home/echristo/tmp")
 !2 = !{}
 !3 = !{i32 2, !"Dwarf Version", i32 3}
 !4 = !{i32 1, !"Debug Info Version", i32 3}
+!5 = !{!6}
+!6 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)

diff --git a/llvm/test/DebugInfo/X86/gnu-public-names-empty.ll b/llvm/test/DebugInfo/X86/gnu-public-names-empty.ll
index 069674c..c5d44ad 100644 (file)
--- a/llvm/test/DebugInfo/X86/gnu-public-names-empty.ll
+++ b/llvm/test/DebugInfo/X86/gnu-public-names-empty.ll
@@ -17,8 +17,10 @@
 !llvm.dbg.cu = !{!0}
 !llvm.module.flags = !{!3, !4}
 
-!0 = distinct !DICompileUnit(language: DW_LANG_C99, producer: "clang version 3.4 (trunk 191846) (llvm/trunk 191866)", isOptimized: false, emissionKind: FullDebug, file: !1, enums: !2, retainedTypes: !2, globals: !2, imports: !2)
+!0 = distinct !DICompileUnit(language: DW_LANG_C99, producer: "clang version 3.4 (trunk 191846) (llvm/trunk 191866)", isOptimized: false, emissionKind: FullDebug, file: !1, enums: !2, retainedTypes: !5, globals: !2, imports: !2)
 !1 = !DIFile(filename: "foo.c", directory: "/usr/local/google/home/echristo/tmp")
 !2 = !{}
 !3 = !{i32 2, !"Dwarf Version", i32 4}
 !4 = !{i32 1, !"Debug Info Version", i32 3}
+!5 = !{!6}
+!6 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)

diff --git a/llvm/test/DebugInfo/dwo.ll b/llvm/test/DebugInfo/dwo.ll
index 5eeca54..b6de943 100644 (file)
--- a/llvm/test/DebugInfo/dwo.ll
+++ b/llvm/test/DebugInfo/dwo.ll
@@ -8,8 +8,10 @@
 !llvm.dbg.cu = !{!0}
 !llvm.module.flags = !{!3, !4}
 
-!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "LLVM", isOptimized: false, runtimeVersion: 2, emissionKind: FullDebug, enums: !2, retainedTypes: !2, globals: !2, imports: !2, dwoId: 43981)
+!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "LLVM", isOptimized: false, runtimeVersion: 2, emissionKind: FullDebug, enums: !2, retainedTypes: !5, globals: !2, imports: !2, dwoId: 43981)
 !1 = !DIFile(filename: "<stdin>", directory: "/")
 !2 = !{}
 !3 = !{i32 2, !"Dwarf Version", i32 4}
 !4 = !{i32 2, !"Debug Info Version", i32 3}
+!5 = !{!6}
+!6 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)

diff --git a/llvm/test/DebugInfo/omit-empty.ll b/llvm/test/DebugInfo/omit-empty.ll
new file mode 100644 (file)
index 0000000..9245005
--- /dev/null
+++ b/llvm/test/DebugInfo/omit-empty.ll
@@ -0,0 +1,12 @@
+; RUN: %llc_dwarf %s -filetype=obj -o - | llvm-objdump -h - | FileCheck %s
+
+; CHECK-NOT: .debug_
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!3, !4}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "LLVM", isOptimized: false, runtimeVersion: 2, emissionKind: FullDebug, enums: !2, retainedTypes: !2, globals: !2, imports: !2)
+!1 = !DIFile(filename: "<stdin>", directory: "/")
+!2 = !{}
+!3 = !{i32 2, !"Dwarf Version", i32 4}
+!4 = !{i32 2, !"Debug Info Version", i32 3}

diff --git a/llvm/test/DebugInfo/skeletoncu.ll b/llvm/test/DebugInfo/skeletoncu.ll
index a90c8b3..4c96d82 100644 (file)
--- a/llvm/test/DebugInfo/skeletoncu.ll
+++ b/llvm/test/DebugInfo/skeletoncu.ll
@@ -8,9 +8,11 @@
 !llvm.dbg.cu = !{!0}
 !llvm.module.flags = !{!3, !4}
 
-!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "LLVM", isOptimized: false, runtimeVersion: 2, splitDebugFilename: "my.dwo", emissionKind: FullDebug, enums: !2, retainedTypes: !2, globals: !2, imports: !2, dwoId: 43981)
+!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "LLVM", isOptimized: false, runtimeVersion: 2, splitDebugFilename: "my.dwo", emissionKind: FullDebug, enums: !2, retainedTypes: !6, globals: !2, imports: !2, dwoId: 43981)
 !1 = !DIFile(filename: "<stdin>", directory: "/")
 !2 = !{}
 !3 = !{i32 2, !"Dwarf Version", i32 4}
 !4 = !{i32 2, !"Debug Info Version", i32 3}
+!5 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+!6 = !{!5}