[ObjectYAML] [DWARF] Abstract DWARF Initial Length values

In the DWARF 4 Spec section 7.2.2, data in many DWARF sections, and some DWARF structures start with "Initial Length Values", which are a 32-bit length, and an optional 64-bit length if the 32 bit value == UINT32_MAX.

This patch abstracts the Initial Length type in YAML, and extends its use to all the DWARF structures that are supported in the DWARFYAML code that have Initial Length values.

llvm-svn: 296911

diff --git a/llvm/include/llvm/ObjectYAML/DWARFYAML.h b/llvm/include/llvm/ObjectYAML/DWARFYAML.h
index d031b5a..f287f70 100644 (file)
--- a/llvm/include/llvm/ObjectYAML/DWARFYAML.h
+++ b/llvm/include/llvm/ObjectYAML/DWARFYAML.h
@@ -13,7 +13,6 @@
 ///
 //===----------------------------------------------------------------------===//
 
-
 #ifndef LLVM_OBJECTYAML_DWARFYAML_H
 #define LLVM_OBJECTYAML_DWARFYAML_H
 
@@ -23,6 +22,26 @@
 namespace llvm {
 namespace DWARFYAML {
 
+struct InitialLength {
+  uint32_t TotalLength;
+  uint64_t TotalLength64;
+
+  bool isDWARF64() const { return TotalLength == UINT32_MAX; }
+
+  uint64_t getLength() const {
+    return isDWARF64() ? TotalLength64 : TotalLength;
+  }
+
+  void setLength(uint64_t Len) {
+    if (Len >= (uint64_t)UINT32_MAX) {
+      TotalLength64 = Len;
+      TotalLength = UINT32_MAX;
+    } else {
+      TotalLength = Len;
+    }
+  }
+};
+
 struct AttributeAbbrev {
   llvm::dwarf::Attribute Attribute;
   llvm::dwarf::Form Form;
@@ -41,7 +60,7 @@ struct ARangeDescriptor {
 };
 
 struct ARange {
-  uint32_t Length;
+  InitialLength Length;
   uint16_t Version;
   uint32_t CuOffset;
   uint8_t AddrSize;
@@ -58,7 +77,7 @@ struct PubEntry {
 struct PubSection {
   PubSection() : IsGNUStyle(false) {}
 
-  uint32_t Length;
+  InitialLength Length;
   uint16_t Version;
   uint32_t UnitOffset;
   uint32_t UnitSize;
@@ -78,7 +97,7 @@ struct Entry {
 };
 
 struct Unit {
-  uint32_t Length;
+  InitialLength Length;
   uint16_t Version;
   uint32_t AbbrOffset;
   uint8_t AddrSize;
@@ -104,8 +123,7 @@ struct LineTableOpcode {
 };
 
 struct LineTable {
-  uint32_t TotalLength;
-  uint64_t TotalLength64;
+  InitialLength Length;
   uint16_t Version;
   uint64_t PrologueLength;
   uint8_t MinInstLength;
@@ -130,7 +148,7 @@ struct Data {
 
   PubSection GNUPubNames;
   PubSection GNUPubTypes;
-  
+
   std::vector<Unit> CompileUnits;
 
   std::vector<LineTable> DebugLines;
@@ -203,7 +221,7 @@ template <> struct MappingTraits<DWARFYAML::FormValue> {
 template <> struct MappingTraits<DWARFYAML::File> {
   static void mapping(IO &IO, DWARFYAML::File &File);
 };
-  
+
 template <> struct MappingTraits<DWARFYAML::LineTableOpcode> {
   static void mapping(IO &IO, DWARFYAML::LineTableOpcode &LineTableOpcode);
 };
@@ -212,6 +230,10 @@ template <> struct MappingTraits<DWARFYAML::LineTable> {
   static void mapping(IO &IO, DWARFYAML::LineTable &LineTable);
 };
 
+template <> struct MappingTraits<DWARFYAML::InitialLength> {
+  static void mapping(IO &IO, DWARFYAML::InitialLength &DWARF);
+};
+
 #define HANDLE_DW_TAG(unused, name)                                            \
   io.enumCase(value, "DW_TAG_" #name, dwarf::DW_TAG_##name);
 

diff --git a/llvm/lib/ObjectYAML/DWARFEmitter.cpp b/llvm/lib/ObjectYAML/DWARFEmitter.cpp
index 2c2d895..69f7d36 100644 (file)
--- a/llvm/lib/ObjectYAML/DWARFEmitter.cpp
+++ b/llvm/lib/ObjectYAML/DWARFEmitter.cpp
@@ -50,6 +50,13 @@ static void ZeroFillBytes(raw_ostream &OS, size_t Size) {
   OS.write(reinterpret_cast<char *>(FillData.data()), Size);
 }
 
+void writeInitialLength(const DWARFYAML::InitialLength &Length, raw_ostream &OS,
+                        bool IsLittleEndian) {
+  writeInteger((uint32_t)Length.TotalLength, OS, IsLittleEndian);
+  if (Length.isDWARF64())
+    writeInteger((uint64_t)Length.TotalLength64, OS, IsLittleEndian);
+}
+
 void DWARFYAML::EmitDebugStr(raw_ostream &OS, const DWARFYAML::Data &DI) {
   for (auto Str : DI.DebugStrings) {
     OS.write(Str.data(), Str.size());
@@ -74,7 +81,7 @@ void DWARFYAML::EmitDebugAbbrev(raw_ostream &OS, const DWARFYAML::Data &DI) {
 void DWARFYAML::EmitDebugAranges(raw_ostream &OS, const DWARFYAML::Data &DI) {
   for (auto Range : DI.ARanges) {
     auto HeaderStart = OS.tell();
-    writeInteger((uint32_t)Range.Length, OS, DI.IsLittleEndian);
+    writeInitialLength(Range.Length, OS, DI.IsLittleEndian);
     writeInteger((uint16_t)Range.Version, OS, DI.IsLittleEndian);
     writeInteger((uint32_t)Range.CuOffset, OS, DI.IsLittleEndian);
     writeInteger((uint8_t)Range.AddrSize, OS, DI.IsLittleEndian);
@@ -97,7 +104,7 @@ void DWARFYAML::EmitDebugAranges(raw_ostream &OS, const DWARFYAML::Data &DI) {
 void DWARFYAML::EmitPubSection(raw_ostream &OS,
                                const DWARFYAML::PubSection &Sect,
                                bool IsLittleEndian) {
-  writeInteger((uint32_t)Sect.Length, OS, IsLittleEndian);
+  writeInitialLength(Sect.Length, OS, IsLittleEndian);
   writeInteger((uint16_t)Sect.Version, OS, IsLittleEndian);
   writeInteger((uint32_t)Sect.UnitOffset, OS, IsLittleEndian);
   writeInteger((uint32_t)Sect.UnitSize, OS, IsLittleEndian);
@@ -113,7 +120,7 @@ void DWARFYAML::EmitPubSection(raw_ostream &OS,
 void DWARFYAML::EmitDebugInfo(raw_ostream &OS, const DWARFYAML::Data &DI) {
 
   for (auto CU : DI.CompileUnits) {
-    writeInteger((uint32_t)CU.Length, OS, DI.IsLittleEndian);
+    writeInitialLength(CU.Length, OS, DI.IsLittleEndian);
     writeInteger((uint16_t)CU.Version, OS, DI.IsLittleEndian);
     writeInteger((uint32_t)CU.AbbrOffset, OS, DI.IsLittleEndian);
     writeInteger((uint8_t)CU.AddrSize, OS, DI.IsLittleEndian);
@@ -246,12 +253,8 @@ static void EmitFileEntry(raw_ostream &OS, const DWARFYAML::File &File) {
 
 void DWARFYAML::EmitDebugLine(raw_ostream &OS, const DWARFYAML::Data &DI) {
   for (const auto &LineTable : DI.DebugLines) {
-    writeInteger((uint32_t)LineTable.TotalLength, OS, DI.IsLittleEndian);
-    uint64_t SizeOfPrologueLength = 4;
-    if (LineTable.TotalLength == UINT32_MAX) {
-      writeInteger((uint64_t)LineTable.TotalLength64, OS, DI.IsLittleEndian);
-      SizeOfPrologueLength = 8;
-    }
+    writeInitialLength(LineTable.Length, OS, DI.IsLittleEndian);
+    uint64_t SizeOfPrologueLength = LineTable.Length.isDWARF64() ? 8 : 4;
     writeInteger((uint16_t)LineTable.Version, OS, DI.IsLittleEndian);
     writeVariableSizedInteger(LineTable.PrologueLength, SizeOfPrologueLength,
                               OS, DI.IsLittleEndian);

diff --git a/llvm/lib/ObjectYAML/DWARFYAML.cpp b/llvm/lib/ObjectYAML/DWARFYAML.cpp
index 014e63f..f55d59a 100644 (file)
--- a/llvm/lib/ObjectYAML/DWARFYAML.cpp
+++ b/llvm/lib/ObjectYAML/DWARFYAML.cpp
@@ -144,9 +144,7 @@ void MappingTraits<DWARFYAML::LineTableOpcode>::mapping(
 
 void MappingTraits<DWARFYAML::LineTable>::mapping(
     IO &IO, DWARFYAML::LineTable &LineTable) {
-  IO.mapRequired("TotalLength", LineTable.TotalLength);
-  if (LineTable.TotalLength == UINT32_MAX)
-    IO.mapRequired("TotalLength64", LineTable.TotalLength64);
+  IO.mapRequired("Length", LineTable.Length);
   IO.mapRequired("Version", LineTable.Version);
   IO.mapRequired("PrologueLength", LineTable.PrologueLength);
   IO.mapRequired("MinInstLength", LineTable.MinInstLength);
@@ -162,6 +160,13 @@ void MappingTraits<DWARFYAML::LineTable>::mapping(
   IO.mapRequired("Opcodes", LineTable.Opcodes);
 }
 
+void MappingTraits<DWARFYAML::InitialLength>::mapping(
+    IO &IO, DWARFYAML::InitialLength &InitialLength) {
+  IO.mapRequired("TotalLength", InitialLength.TotalLength);
+  if (InitialLength.isDWARF64())
+    IO.mapRequired("TotalLength64", InitialLength.TotalLength64);
+}
+
 } // namespace llvm::yaml
 
 } // namespace llvm

diff --git a/llvm/test/ObjectYAML/MachO/DWARF-debug_aranges.yaml b/llvm/test/ObjectYAML/MachO/DWARF-debug_aranges.yaml
index 2822c94..0b0421d 100644 (file)
--- a/llvm/test/ObjectYAML/MachO/DWARF-debug_aranges.yaml
+++ b/llvm/test/ObjectYAML/MachO/DWARF-debug_aranges.yaml
@@ -313,7 +313,8 @@ LinkEditData:
     - _main
 DWARF:           
   debug_aranges:   
-    - Length:          44
+    - Length:          
+        TotalLength:     44
       Version:         2
       CuOffset:        0
       AddrSize:        8
@@ -325,7 +326,8 @@ DWARF:
 
 #CHECK: DWARF:           
 #CHECK:   debug_aranges:   
-#CHECK:     - Length:          44
+#CHECK:     - Length:          
+#CHECK:         TotalLength:     44
 #CHECK:       Version:         2
 #CHECK:       CuOffset:        0
 #CHECK:       AddrSize:        8

diff --git a/llvm/test/ObjectYAML/MachO/DWARF-debug_info.yaml b/llvm/test/ObjectYAML/MachO/DWARF-debug_info.yaml
index b1b6b8a..0ede72b 100644 (file)
--- a/llvm/test/ObjectYAML/MachO/DWARF-debug_info.yaml
+++ b/llvm/test/ObjectYAML/MachO/DWARF-debug_info.yaml
@@ -375,7 +375,8 @@ DWARF:
         - Attribute:       DW_AT_type
           Form:            DW_FORM_ref4
   debug_aranges:   
-    - Length:          44
+    - Length:          
+        TotalLength:     44
       Version:         2
       CuOffset:        0
       AddrSize:        8
@@ -384,7 +385,8 @@ DWARF:
         - Address:         0x0000000100000F50
           Length:          52
   debug_info:      
-    - Length:          117
+    - Length:          
+        TotalLength:     117
       Version:         4
       AbbrOffset:      0
       AddrSize:        8
@@ -452,7 +454,8 @@ DWARF:
         - AbbrCode:        0x00000000
           Values:          
   debug_line:      
-    - TotalLength:     65
+    - Length:          
+        TotalLength:     65
       Version:         2
       PrologueLength:  36
       MinInstLength:   1
@@ -508,7 +511,8 @@ DWARF:
 
 #CHECK: DWARF:           
 #CHECK:   debug_info:      
-#CHECK:     - Length:          117
+#CHECK:     - Length:          
+#CHECK:         TotalLength:     117
 #CHECK:       Version:         4
 #CHECK:       AbbrOffset:      0
 #CHECK:       AddrSize:        8

diff --git a/llvm/test/ObjectYAML/MachO/DWARF-debug_line.yaml b/llvm/test/ObjectYAML/MachO/DWARF-debug_line.yaml
index c1e0158..692b501 100644 (file)
--- a/llvm/test/ObjectYAML/MachO/DWARF-debug_line.yaml
+++ b/llvm/test/ObjectYAML/MachO/DWARF-debug_line.yaml
@@ -394,7 +394,8 @@ DWARF:
         - Attribute:       DW_AT_type
           Form:            DW_FORM_ref4
   debug_aranges:   
-    - Length:          44
+    - Length:          
+        TotalLength:     44
       Version:         2
       CuOffset:        0
       AddrSize:        8
@@ -403,7 +404,8 @@ DWARF:
         - Address:         0x0000000100000F50
           Length:          52
   debug_pubnames:  
-    Length:          23
+    Length:          
+      TotalLength:     23
     Version:         2
     UnitOffset:      0
     UnitSize:        121
@@ -411,7 +413,8 @@ DWARF:
       - DieOffset:       0x0000002A
         Name:            main
   debug_pubtypes:  
-    Length:          31
+    Length:          
+      TotalLength:     31
     Version:         2
     UnitOffset:      0
     UnitSize:        121
@@ -421,7 +424,8 @@ DWARF:
       - DieOffset:       0x00000071
         Name:            char
   debug_info:      
-    - Length:          117
+    - Length:          
+        TotalLength:     117
       Version:         4
       AbbrOffset:      0
       AddrSize:        8
@@ -489,7 +493,8 @@ DWARF:
         - AbbrCode:        0x00000000
           Values:          
   debug_line:      
-    - TotalLength:     65
+    - Length:          
+        TotalLength:     65
       Version:         2
       PrologueLength:  36
       MinInstLength:   1
@@ -542,7 +547,8 @@ DWARF:
 ...
 
 #CHECK:   debug_line:      
-#CHECK:     - TotalLength:     65
+#CHECK:     - Length:          
+#CHECK:         TotalLength:     65
 #CHECK:       Version:         2
 #CHECK:       PrologueLength:  36
 #CHECK:       MinInstLength:   1

diff --git a/llvm/test/ObjectYAML/MachO/DWARF-pubsections.yaml b/llvm/test/ObjectYAML/MachO/DWARF-pubsections.yaml
index 8535ed0..a3c05ca 100644 (file)
--- a/llvm/test/ObjectYAML/MachO/DWARF-pubsections.yaml
+++ b/llvm/test/ObjectYAML/MachO/DWARF-pubsections.yaml
@@ -314,7 +314,8 @@ DWARF:
     - int
     - char
   debug_pubnames:  
-    Length:          23
+    Length:
+      TotalLength:       23
     Version:         2
     UnitOffset:      0
     UnitSize:        121
@@ -322,7 +323,8 @@ DWARF:
       - DieOffset:       0x0000002A
         Name:            main
   debug_pubtypes:  
-    Length:          31
+    Length:
+      TotalLength:       31
     Version:         2
     UnitOffset:      0
     UnitSize:        121
@@ -335,7 +337,8 @@ DWARF:
 
 #CHECK: DWARF:           
 #CHECK:   debug_pubnames:  
-#CHECK:     Length:          23
+#CHECK:     Length:
+#CHECK:       TotalLength:       23
 #CHECK:     Version:         2
 #CHECK:     UnitOffset:      0
 #CHECK:     UnitSize:        121
@@ -343,7 +346,8 @@ DWARF:
 #CHECK:       - DieOffset:       0x0000002A
 #CHECK:         Name:            main
 #CHECK:   debug_pubtypes:  
-#CHECK:     Length:          31
+#CHECK:     Length:
+#CHECK:       TotalLength:       31
 #CHECK:     Version:         2
 #CHECK:     UnitOffset:      0
 #CHECK:     UnitSize:        121

diff --git a/llvm/tools/obj2yaml/dwarf2yaml.cpp b/llvm/tools/obj2yaml/dwarf2yaml.cpp
index 4e320cf..7b45f8a 100644 (file)
--- a/llvm/tools/obj2yaml/dwarf2yaml.cpp
+++ b/llvm/tools/obj2yaml/dwarf2yaml.cpp
@@ -17,6 +17,13 @@
 
 using namespace llvm;
 
+void dumpInitialLength(DataExtractor &Data, uint32_t &Offset,
+                       DWARFYAML::InitialLength &InitialLength) {
+  InitialLength.TotalLength = Data.getU32(&Offset);
+  if (InitialLength.isDWARF64())
+    InitialLength.TotalLength64 = Data.getU64(&Offset);
+}
+
 void dumpDebugAbbrev(DWARFContextInMemory &DCtx, DWARFYAML::Data &Y) {
   auto AbbrevSetPtr = DCtx.getDebugAbbrev();
   if (AbbrevSetPtr) {
@@ -55,7 +62,7 @@ void dumpDebugARanges(DWARFContextInMemory &DCtx, DWARFYAML::Data &Y) {
 
   while (Set.extract(ArangesData, &Offset)) {
     DWARFYAML::ARange Range;
-    Range.Length = Set.getHeader().Length;
+    Range.Length.setLength(Set.getHeader().Length);
     Range.Version = Set.getHeader().Version;
     Range.CuOffset = Set.getHeader().CuOffset;
     Range.AddrSize = Set.getHeader().AddrSize;
@@ -74,11 +81,11 @@ void dumpPubSection(DWARFContextInMemory &DCtx, DWARFYAML::PubSection &Y,
                     StringRef Section) {
   DataExtractor PubSectionData(Section, DCtx.isLittleEndian(), 0);
   uint32_t Offset = 0;
-  Y.Length = PubSectionData.getU32(&Offset);
+  dumpInitialLength(PubSectionData, Offset, Y.Length);
   Y.Version = PubSectionData.getU16(&Offset);
   Y.UnitOffset = PubSectionData.getU32(&Offset);
   Y.UnitSize = PubSectionData.getU32(&Offset);
-  while (Offset < Y.Length) {
+  while (Offset < Y.Length.getLength()) {
     DWARFYAML::PubEntry NewEntry;
     NewEntry.DieOffset = PubSectionData.getU32(&Offset);
     if (Y.IsGNUStyle)
@@ -105,7 +112,7 @@ void dumpDebugPubSections(DWARFContextInMemory &DCtx, DWARFYAML::Data &Y) {
 void dumpDebugInfo(DWARFContextInMemory &DCtx, DWARFYAML::Data &Y) {
   for (const auto &CU : DCtx.compile_units()) {
     DWARFYAML::Unit NewUnit;
-    NewUnit.Length = CU->getLength();
+    NewUnit.Length.setLength(CU->getLength());
     NewUnit.Version = CU->getVersion();
     NewUnit.AbbrOffset = CU->getAbbreviations()->getOffset();
     NewUnit.AddrSize = CU->getAddressByteSize();
@@ -233,14 +240,9 @@ void dumpDebugLines(DWARFContextInMemory &DCtx, DWARFYAML::Data &Y) {
       DataExtractor LineData(DCtx.getLineSection().Data, DCtx.isLittleEndian(),
                              CU->getAddressByteSize());
       uint32_t Offset = *StmtOffset;
-      uint64_t SizeOfPrologueLength = 4;
-      DebugLines.TotalLength = LineData.getU32(&Offset);
-      uint64_t LineTableLength = DebugLines.TotalLength;
-      if (DebugLines.TotalLength == UINT32_MAX) {
-        DebugLines.TotalLength64 = LineData.getU64(&Offset);
-        LineTableLength = DebugLines.TotalLength64;
-        SizeOfPrologueLength = 8;
-      }
+      dumpInitialLength(LineData, Offset, DebugLines.Length);
+      uint64_t LineTableLength = DebugLines.Length.getLength();
+      uint64_t SizeOfPrologueLength = DebugLines.Length.isDWARF64() ? 8 : 4;
       DebugLines.Version = LineData.getU16(&Offset);
       DebugLines.PrologueLength =
           LineData.getUnsigned(&Offset, SizeOfPrologueLength);

diff --git a/llvm/unittests/DebugInfo/DWARF/DWARFDebugInfoTest.cpp b/llvm/unittests/DebugInfo/DWARF/DWARFDebugInfoTest.cpp
index 90dd688..b6111e7 100644 (file)
--- a/llvm/unittests/DebugInfo/DWARF/DWARFDebugInfoTest.cpp
+++ b/llvm/unittests/DebugInfo/DWARF/DWARFDebugInfoTest.cpp
@@ -1172,7 +1172,8 @@ TEST(DWARFDebugInfo, TestEmptyChildren) {
                          "    Children:        DW_CHILDREN_yes\n"
                          "    Attributes:\n"
                          "debug_info:\n"
-                         "  - Length:          9\n"
+                         "  - Length:\n"
+                         "      TotalLength:          9\n"
                          "    Version:         4\n"
                          "    AbbrOffset:      0\n"
                          "    AddrSize:        8\n"