[DWARFv5] Dump MD5 checksum from line-table header

[probinson]

Summary

Also adds missing support for DW_FORM_data16, which seems easiest to handle as a fixed-size block.

[probinson]

Ping.

[aprantl]

sgtm. some formatting comments inline.

llvm/lib/CodeGen/AsmPrinter/DIE.cpp

780

for consistency with the surrounding code, perhaps all on one line?

797

same here?

[probinson]

llvm/lib/CodeGen/AsmPrinter/DIE.cpp

780

I agree. clang-format did this, but clearly it wants one line per case.

797

Same here.

llvm/include/llvm/DebugInfo/DWARF/DWARFDebugLine.h

 #ifndef LLVM_DEBUGINFO_DWARFDEBUGLINE_H
 #define LLVM_DEBUGINFO_DWARFDEBUGLINE_H
 
 #include "llvm/ADT/StringRef.h"
 #include "llvm/DebugInfo/DIContext.h"
 #include "llvm/DebugInfo/DWARF/DWARFDataExtractor.h"
 #include "llvm/DebugInfo/DWARF/DWARFFormValue.h"
 #include "llvm/DebugInfo/DWARF/DWARFRelocMap.h"
+#include "llvm/Support/MD5.h"
 #include <cstdint>
 #include <map>
 #include <string>
 #include <vector>
 
 namespace llvm {
 
 class DWARFUnit;
 class raw_ostream;
 
 class DWARFDebugLine {
 public:
   struct FileNameEntry {
     FileNameEntry() = default;
 
     StringRef Name;
     uint64_t DirIdx = 0;
     uint64_t ModTime = 0;
     uint64_t Length = 0;
+    MD5::MD5Result Checksum;
   };
 
   struct Prologue {
     Prologue();
 
     /// The size in bytes of the statement information for this compilation unit
     /// (not including the total_length field itself).
     uint64_t TotalLength;
     /// Version, address size (starting in v5), and DWARF32/64 format; these
     /// parameters affect interpretation of forms (used in the directory and
     /// file tables starting with v5).
     DWARFFormParams FormParams;
-    /// In v5, size in bytes of a segment selector.
-    uint8_t SegSelectorSize;
     /// The number of bytes following the prologue_length field to the beginning
     /// of the first byte of the statement program itself.
     uint64_t PrologueLength;
+    /// In v5, size in bytes of a segment selector.
+    uint8_t SegSelectorSize;
     /// The size in bytes of the smallest target machine instruction. Statement
     /// program opcodes that alter the address register first multiply their
     /// operands by this value.
     uint8_t MinInstLength;
     /// The maximum number of individual operations that may be encoded in an
     /// instruction.
     uint8_t MaxOpsPerInst;
     /// The initial value of theis_stmtregister.
     uint8_t DefaultIsStmt;
     /// This parameter affects the meaning of the special opcodes. See below.
     int8_t LineBase;
     /// This parameter affects the meaning of the special opcodes. See below.
     uint8_t LineRange;
     /// The number assigned to the first special opcode.
     uint8_t OpcodeBase;
+    /// For v5, whether filename entries provide an MD5 checksum.
+    bool HasMD5;
     std::vector<uint8_t> StandardOpcodeLengths;
     std::vector<StringRef> IncludeDirectories;
     std::vector<FileNameEntry> FileNames;
 
     const DWARFFormParams getFormParams() const { return FormParams; }
     uint16_t getVersion() const { return FormParams.Version; }
     uint8_t getAddressSize() const { return FormParams.AddrSize; }
     bool isDWARF64() const { return FormParams.Format == dwarf::DWARF64; }

llvm/lib/CodeGen/AsmPrinter/DIE.cpp

 ///
 void DIEBlock::EmitValue(const AsmPrinter *Asm, dwarf::Form Form) const {
   switch (Form) {
   default: llvm_unreachable("Improper form for block");
   case dwarf::DW_FORM_block1: Asm->EmitInt8(Size);    break;
   case dwarf::DW_FORM_block2: Asm->EmitInt16(Size);   break;
   case dwarf::DW_FORM_block4: Asm->EmitInt32(Size);   break;
   case dwarf::DW_FORM_block:  Asm->EmitULEB128(Size); break;
+  case dwarf::DW_FORM_data16:
+    break;
   }
 
   for (const auto &V : values())
     V.EmitValue(Asm);
 }
 
 /// SizeOf - Determine size of block data in bytes.
 ///
 unsigned DIEBlock::SizeOf(const AsmPrinter *AP, dwarf::Form Form) const {
   switch (Form) {
   case dwarf::DW_FORM_block1: return Size + sizeof(int8_t);
   case dwarf::DW_FORM_block2: return Size + sizeof(int16_t);
   case dwarf::DW_FORM_block4: return Size + sizeof(int32_t);
   case dwarf::DW_FORM_block:  return Size + getULEB128Size(Size);
+  case dwarf::DW_FORM_data16:
+    return 16;
   default: llvm_unreachable("Improper form for block");
   }
 }
 
 LLVM_DUMP_METHOD
 void DIEBlock::print(raw_ostream &O) const {
   printValues(O, *this, "Blk", Size, 5);
 }

llvm/lib/DebugInfo/DWARF/DWARFDebugLine.cpp

 DWARFDebugLine::Prologue::Prologue() { clear(); }
 
 void DWARFDebugLine::Prologue::clear() {
   TotalLength = PrologueLength = 0;
   SegSelectorSize = 0;
   MinInstLength = MaxOpsPerInst = DefaultIsStmt = LineBase = LineRange = 0;
   OpcodeBase = 0;
   FormParams = DWARFFormParams({0, 0, DWARF32});
+  HasMD5 = false;
   StandardOpcodeLengths.clear();
   IncludeDirectories.clear();
   FileNames.clear();
 }
 
 void DWARFDebugLine::Prologue::dump(raw_ostream &OS) const {
   OS << "Line table prologue:\n"
      << format("    total_length: 0x%8.8" PRIx64 "\n", TotalLength)
OS << format("standard_opcode_lengths[%s] = %u\n",
                  LNStandardString(I + 1).data(), StandardOpcodeLengths[I]);
 
   if (!IncludeDirectories.empty())
     for (uint32_t I = 0; I != IncludeDirectories.size(); ++I)
       OS << format("include_directories[%3u] = '", I + 1)
          << IncludeDirectories[I] << "'\n";
 
   if (!FileNames.empty()) {
+    if (HasMD5)
+      OS << "                Dir  MD5 Checksum                     File Name\n"
+         << "                ---- -------------------------------- -----------"
+            "---------------\n";
+    else
       OS << "                Dir  Mod Time   File Len   File Name\n"
          << "                ---- ---------- ---------- -----------"
             "----------------\n";
     for (uint32_t I = 0; I != FileNames.size(); ++I) {
       const FileNameEntry &FileEntry = FileNames[I];
-      OS << format("file_names[%3u] %4" PRIu64 " ", I + 1, FileEntry.DirIdx)
-         << format("0x%8.8" PRIx64 " 0x%8.8" PRIx64 " ", FileEntry.ModTime,
-                   FileEntry.Length)
-         << FileEntry.Name << '\n';
+      OS << format("file_names[%3u] %4" PRIu64 " ", I + 1, FileEntry.DirIdx);
+      if (HasMD5)
+        OS << FileEntry.Checksum.digest();
+      else
+        OS << format("0x%8.8" PRIx64 " 0x%8.8" PRIx64, FileEntry.ModTime,
+                     FileEntry.Length);
+      OS << ' ' << FileEntry.Name << '\n';
     }
   }
 }
 
 // Parse v2-v4 directory and file tables.
 static void
 parseV2DirFileTables(const DWARFDataExtractor &DebugLineData,
                      uint32_t *OffsetPtr, uint64_t EndPrologueOffset,
parseV2DirFileTables(const DWARFDataExtractor &DebugLineData,
   }
 }
 
 // Parse v5 directory/file entry content descriptions.
 // Returns the descriptors, or an empty vector if we did not find a path or
 // ran off the end of the prologue.
 static ContentDescriptors
 parseV5EntryFormat(const DWARFDataExtractor &DebugLineData, uint32_t *OffsetPtr,
-                   uint64_t EndPrologueOffset) {
+                   uint64_t EndPrologueOffset, bool *HasMD5) {
   ContentDescriptors Descriptors;
   int FormatCount = DebugLineData.getU8(OffsetPtr);
   bool HasPath = false;
   for (int I = 0; I != FormatCount; ++I) {
     if (*OffsetPtr >= EndPrologueOffset)
       return ContentDescriptors();
     ContentDescriptor Descriptor;
     Descriptor.Type =
       dwarf::LineNumberEntryFormat(DebugLineData.getULEB128(OffsetPtr));
     Descriptor.Form = dwarf::Form(DebugLineData.getULEB128(OffsetPtr));
     if (Descriptor.Type == dwarf::DW_LNCT_path)
       HasPath = true;
+    else if (Descriptor.Type == dwarf::DW_LNCT_MD5 && HasMD5)
+      *HasMD5 = true;
     Descriptors.push_back(Descriptor);
   }
   return HasPath ? Descriptors : ContentDescriptors();
 }
 
 static bool
 parseV5DirFileTables(const DWARFDataExtractor &DebugLineData,
                      uint32_t *OffsetPtr, uint64_t EndPrologueOffset,
                      const DWARFFormParams &FormParams, const DWARFUnit *U,
-                     std::vector<StringRef> &IncludeDirectories,
+                     bool &HasMD5, std::vector<StringRef> &IncludeDirectories,
                      std::vector<DWARFDebugLine::FileNameEntry> &FileNames) {
   // Get the directory entry description.
   ContentDescriptors DirDescriptors =
-    parseV5EntryFormat(DebugLineData, OffsetPtr, EndPrologueOffset);
+      parseV5EntryFormat(DebugLineData, OffsetPtr, EndPrologueOffset, nullptr);
   if (DirDescriptors.empty())
     return false;
 
   // Get the directory entries, according to the format described above.
   int DirEntryCount = DebugLineData.getU8(OffsetPtr);
   for (int I = 0; I != DirEntryCount; ++I) {
     if (*OffsetPtr >= EndPrologueOffset)
       return false;
for (auto Descriptor : DirDescriptors) {
         if (!Value.skipValue(DebugLineData, OffsetPtr, FormParams))
           return false;
       }
     }
   }
 
   // Get the file entry description.
   ContentDescriptors FileDescriptors =
-    parseV5EntryFormat(DebugLineData, OffsetPtr, EndPrologueOffset);
+      parseV5EntryFormat(DebugLineData, OffsetPtr, EndPrologueOffset, &HasMD5);
   if (FileDescriptors.empty())
     return false;
 
   // Get the file entries, according to the format described above.
   int FileEntryCount = DebugLineData.getU8(OffsetPtr);
   for (int I = 0; I != FileEntryCount; ++I) {
     if (*OffsetPtr >= EndPrologueOffset)
       return false;
for (auto Descriptor : FileDescriptors) {
         FileEntry.DirIdx = Value.getAsUnsignedConstant().getValue();
         break;
       case DW_LNCT_timestamp:
         FileEntry.ModTime = Value.getAsUnsignedConstant().getValue();
         break;
       case DW_LNCT_size:
         FileEntry.Length = Value.getAsUnsignedConstant().getValue();
         break;
-      // FIXME: Add MD5
+      case DW_LNCT_MD5:
+        assert(Value.getAsBlock().getValue().size() == 16);
+        std::uninitialized_copy_n(Value.getAsBlock().getValue().begin(), 16,
+                                  FileEntry.Checksum.Bytes.begin());
+        break;
       default:
         break;
       }
     }
     FileNames.push_back(FileEntry);
   }
   return true;
 }
bool DWARFDebugLine::Prologue::parse(const DWARFDataExtractor &DebugLineData,
   StandardOpcodeLengths.reserve(OpcodeBase - 1);
   for (uint32_t I = 1; I < OpcodeBase; ++I) {
     uint8_t OpLen = DebugLineData.getU8(OffsetPtr);
     StandardOpcodeLengths.push_back(OpLen);
   }
 
   if (getVersion() >= 5) {
     if (!parseV5DirFileTables(DebugLineData, OffsetPtr, EndPrologueOffset,
-                              getFormParams(), U, IncludeDirectories,
+                              getFormParams(), U, HasMD5, IncludeDirectories,
                               FileNames)) {
       fprintf(stderr,
               "warning: parsing line table prologue at 0x%8.8" PRIx64
               " found an invalid directory or file table description at"
               " 0x%8.8" PRIx64 "\n", PrologueOffset, (uint64_t)*OffsetPtr);
       return false;
     }
   } else

llvm/lib/DebugInfo/DWARF/DWARFFormValue.cpp

do {
 
     case DW_FORM_addr:
     case DW_FORM_ref_addr:
     case DW_FORM_flag_present:
     case DW_FORM_data1:
     case DW_FORM_data2:
     case DW_FORM_data4:
     case DW_FORM_data8:
+    case DW_FORM_data16:
     case DW_FORM_flag:
     case DW_FORM_ref1:
     case DW_FORM_ref2:
     case DW_FORM_ref4:
     case DW_FORM_ref8:
     case DW_FORM_ref_sig8:
     case DW_FORM_ref_sup4:
     case DW_FORM_ref_sup8:
do {
     case DW_FORM_addrx4:
       Value.uval = Data.getRelocatedValue(4, OffsetPtr);
       break;
     case DW_FORM_data8:
     case DW_FORM_ref8:
     case DW_FORM_ref_sup8:
       Value.uval = Data.getU64(OffsetPtr);
       break;
+    case DW_FORM_data16:
+      // Treat this like a 16-byte block.
+      Value.uval = 16;
+      IsBlock = true;
+      break;
     case DW_FORM_sdata:
       Value.sval = Data.getSLEB128(OffsetPtr);
       break;
     case DW_FORM_udata:
     case DW_FORM_ref_udata:
       Value.uval = Data.getULEB128(OffsetPtr);
       break;
     case DW_FORM_string:
case DW_FORM_data4:
     OS << format("0x%08x", (uint32_t)UValue);
     break;
   case DW_FORM_ref_sig8:
     AddrOS << format("0x%016" PRIx64, UValue);
     break;
   case DW_FORM_data8:
     OS << format("0x%016" PRIx64, UValue);
     break;
+  case DW_FORM_data16:
+    OS << format_bytes(ArrayRef<uint8_t>(Value.data, 16), None, 16, 16);
+    break;
   case DW_FORM_string:
     OS << '"';
     OS.write_escaped(Value.cstr);
     OS << '"';
     break;
   case DW_FORM_exprloc:
   case DW_FORM_block:
   case DW_FORM_block1:
Optional<int64_t> DWARFFormValue::getAsSignedConstant() const {
   case DW_FORM_sdata:
   case DW_FORM_data8:
   default:
     return Value.sval;
   }
 }
 
 Optional<ArrayRef<uint8_t>> DWARFFormValue::getAsBlock() const {
-  if (!isFormClass(FC_Block) && !isFormClass(FC_Exprloc))
+  if (!isFormClass(FC_Block) && !isFormClass(FC_Exprloc) &&
+      Form != DW_FORM_data16)
     return None;
   return makeArrayRef(Value.data, Value.uval);
 }
 
 Optional<uint64_t> DWARFFormValue::getAsCStringOffset() const {
   if (!isFormClass(FC_String) && Form == DW_FORM_string)
     return None;
   return Value.uval;
 }
 
 Optional<uint64_t> DWARFFormValue::getAsReferenceUVal() const {
   if (!isFormClass(FC_Reference))
     return None;
   return Value.uval;
 }

llvm/test/DebugInfo/X86/dwarfdump-header.s

LH_5_params:
         .byte   1               # One element per directory entry
         .byte   1               # DW_LNCT_path
         .byte   0x0e            # DW_FORM_strp (-> .debug_str)
         # Directory table entries
         .byte   2               # Two directories
         .long   str_LT_5a
         .long   str_LT_5b
         # File table format
-        .byte   4               # Four elements per file entry
+        .byte   3               # Three elements per file entry
         .byte   1               # DW_LNCT_path
         .byte   0x08            # DW_FORM_string
         .byte   2               # DW_LNCT_directory_index
         .byte   0x0b            # DW_FORM_data1
-        .byte   3               # DW_LNCT_timestamp
-        .byte   0x0f            # DW_FORM_udata
-        .byte   4               # DW_LNCT_size
-        .byte   0x0f            # DW_FORM_udata
+        .byte   5               # DW_LNCT_MD5
+        .byte   0x1e            # DW_FORM_data16
         # File table entries
         .byte   2               # Two files
         .asciz "File5a"
         .byte   1
-        .byte   0x51
-        .byte   0x52
+        .quad   0x7766554433221100
+        .quad   0xffeeddccbbaa9988
         .asciz "File5b"
         .byte   2
-        .byte   0x53
-        .byte   0x54
+        .quad   0x8899aabbccddeeff
+        .quad   0x0011223344556677
 LH_5_header_end:
         # Line number program, which is empty.
 LH_5_end:
 
 # CHECK: Line table prologue:
 # CHECK: version: 5
 # CHECK: address_size: 8
 # CHECK: seg_select_size: 0
 # CHECK: max_ops_per_inst: 1
 # CHECK: include_directories[  1] = 'Directory5a'
 # CHECK: include_directories[  2] = 'Directory5b'
 # CHECK-NOT: include_directories
-# CHECK: file_names[  1]    1 0x00000051 0x00000052 File5a{{$}}
-# CHECK: file_names[  2]    2 0x00000053 0x00000054 File5b{{$}}
+# CHECK: MD5 Checksum
+# CHECK: file_names[  1]    1 00112233445566778899aabbccddeeff File5a{{$}}
+# CHECK: file_names[  2]    2 ffeeddccbbaa99887766554433221100 File5b{{$}}
 # CHECK-NOT: file_names
 
   .section .debug_line.dwo,"",@progbits
 # CHECK-LABEL: .debug_line.dwo
 
 # DWARF v5 DWO line-table header.
 dwo_LH_5_start:
         .long   dwo_LH_5_end-dwo_LH_5_version   # Length of Unit

llvm/unittests/DebugInfo/DWARF/DWARFDebugInfoTest.cpp

void TestAllForms() {
   const uint8_t BlockData[] = {1, 2, 3, 4, 5, 6, 7, 8, 9, 0};
   const uint32_t BlockSize = sizeof(BlockData);
   const RefAddrType RefAddr = 0x12345678;
   const uint8_t Data1 = 0x01U;
   const uint16_t Data2 = 0x2345U;
   const uint32_t Data4 = 0x6789abcdU;
   const uint64_t Data8 = 0x0011223344556677ULL;
   const uint64_t Data8_2 = 0xAABBCCDDEEFF0011ULL;
+  const uint8_t Data16[16] = {1, 2,  3,  4,  5,  6,  7,  8,
+                              9, 10, 11, 12, 13, 14, 15, 16};
   const int64_t SData = INT64_MIN;
   const int64_t ICSData = INT64_MAX; // DW_FORM_implicit_const SData
   const uint64_t UData[] = {UINT64_MAX - 1, UINT64_MAX - 2, UINT64_MAX - 3,
                             UINT64_MAX - 4, UINT64_MAX - 5, UINT64_MAX - 6,
                             UINT64_MAX - 7, UINT64_MAX - 8, UINT64_MAX - 9};
 #define UDATA_1 18446744073709551614ULL
   const uint32_t Dwarf32Values[] = {1, 2, 3, 4, 5, 6, 7, 8};
   const char *StringValue = "Hello";
#define UDATA_1 18446744073709551614ULL
   CUDie.addAttribute(Attr_DW_FORM_block1, DW_FORM_block1, BlockData, BlockSize);
 
   const auto Attr_DW_FORM_block2 = static_cast<dwarf::Attribute>(Attr++);
   CUDie.addAttribute(Attr_DW_FORM_block2, DW_FORM_block2, BlockData, BlockSize);
 
   const auto Attr_DW_FORM_block4 = static_cast<dwarf::Attribute>(Attr++);
   CUDie.addAttribute(Attr_DW_FORM_block4, DW_FORM_block4, BlockData, BlockSize);
 
+  // We handle data16 as a block form.
+  const auto Attr_DW_FORM_data16 = static_cast<dwarf::Attribute>(Attr++);
+  if (Version >= 5)
+    CUDie.addAttribute(Attr_DW_FORM_data16, DW_FORM_data16, Data16, 16);
+
   //----------------------------------------------------------------------
   // Test data forms
   //----------------------------------------------------------------------
   const auto Attr_DW_FORM_data1 = static_cast<dwarf::Attribute>(Attr++);
   CUDie.addAttribute(Attr_DW_FORM_data1, DW_FORM_data1, Data1);
 
   const auto Attr_DW_FORM_data2 = static_cast<dwarf::Attribute>(Attr++);
   CUDie.addAttribute(Attr_DW_FORM_data2, DW_FORM_data2, Data2);
#define UDATA_1 18446744073709551614ULL
   FormValue = DieDG.find(Attr_DW_FORM_block4);
   EXPECT_TRUE((bool)FormValue);
   BlockDataOpt = FormValue->getAsBlock();
   EXPECT_TRUE(BlockDataOpt.hasValue());
   ExtractedBlockData = BlockDataOpt.getValue();
   EXPECT_EQ(ExtractedBlockData.size(), BlockSize);
   EXPECT_TRUE(memcmp(ExtractedBlockData.data(), BlockData, BlockSize) == 0);
 
+  // Data16 is handled like a block.
+  if (Version >= 5) {
+    FormValue = DieDG.find(Attr_DW_FORM_data16);
+    EXPECT_TRUE((bool)FormValue);
+    BlockDataOpt = FormValue->getAsBlock();
+    EXPECT_TRUE(BlockDataOpt.hasValue());
+    ExtractedBlockData = BlockDataOpt.getValue();
+    EXPECT_EQ(ExtractedBlockData.size(), 16u);
+    EXPECT_TRUE(memcmp(ExtractedBlockData.data(), Data16, 16) == 0);
+  }
+
   //----------------------------------------------------------------------
   // Test data forms
   //----------------------------------------------------------------------
   EXPECT_EQ(Data1, toUnsigned(DieDG.find(Attr_DW_FORM_data1), 0));
   EXPECT_EQ(Data2, toUnsigned(DieDG.find(Attr_DW_FORM_data2), 0));
   EXPECT_EQ(Data4, toUnsigned(DieDG.find(Attr_DW_FORM_data4), 0));
   EXPECT_EQ(Data8, toUnsigned(DieDG.find(Attr_DW_FORM_data8), 0));
 

llvm/unittests/DebugInfo/DWARF/DWARFFormValueTest.cpp

TEST(DWARFFormValue, SignedConstantForms) {
   EXPECT_EQ(Data1.getAsSignedConstant().getValue(), 120);
   EXPECT_EQ(Data2.getAsSignedConstant().getValue(), 32000);
   EXPECT_EQ(Data4.getAsSignedConstant().getValue(), 2000000000);
   EXPECT_EQ(Data8.getAsSignedConstant().getValue(), 0x1234567812345678LL);
   EXPECT_EQ(LEBMin.getAsSignedConstant().getValue(), LLONG_MIN);
   EXPECT_EQ(LEBMax.getAsSignedConstant().getValue(), LLONG_MAX);
   EXPECT_EQ(LEB1.getAsSignedConstant().getValue(), -42);
   EXPECT_EQ(LEB2.getAsSignedConstant().getValue(), 42);
+
+  // Data16 is a little tricky.
+  using uint128_t = std::array<uint8_t, 16>;
+  uint128_t Item16({0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15});
+  auto Data16 = createDataXFormValue<uint128_t>(DW_FORM_data16, Item16);
+  SmallString<32> Str;
+  raw_svector_ostream Res(Str);
+  Data16.dump(Res, DIDumpOptions());
+  EXPECT_EQ(memcmp(Str.data(), "000102030405060708090a0b0c0d0e0f", 32), 0);
 }
 
 } // end anonymous namespace