[WebAssembly] Added R_WASM_FUNCTION_OFFSET_I64 for use with DWARF DW_AT_low_pc

[aardappel]

Summary

Needed for wasm64, see discussion in https://reviews.llvm.org/D91203

lld/wasm/InputChunks.cpp

for (const WasmRelocation &rel : relocations) {
     case R_WASM_MEMORY_ADDR_I32:
     case R_WASM_FUNCTION_OFFSET_I32:
     case R_WASM_SECTION_OFFSET_I32:
     case R_WASM_GLOBAL_INDEX_I32:
       existingValue = read32le(loc);
       break;
     case R_WASM_TABLE_INDEX_I64:
     case R_WASM_MEMORY_ADDR_I64:
+    case R_WASM_FUNCTION_OFFSET_I64:
       existingValue = read64le(loc);
       break;
     default:
       llvm_unreachable("unknown relocation type");
     }
 
     if (bytesRead && bytesRead != paddedLEBWidth)
       warn("expected LEB at relocation site be 5/10-byte padded");
for (const WasmRelocation &rel : relocations) {
     case R_WASM_MEMORY_ADDR_I32:
     case R_WASM_FUNCTION_OFFSET_I32:
     case R_WASM_SECTION_OFFSET_I32:
     case R_WASM_GLOBAL_INDEX_I32:
       write32le(loc, value);
       break;
     case R_WASM_TABLE_INDEX_I64:
     case R_WASM_MEMORY_ADDR_I64:
+    case R_WASM_FUNCTION_OFFSET_I64:
       write64le(loc, value);
       break;
     default:
       llvm_unreachable("unknown relocation type");
     }
   }
 }
 

lld/wasm/InputFiles.cpp

uint64_t ObjFile::calcNewAddend(const WasmRelocation &reloc) const {
   case R_WASM_MEMORY_ADDR_LEB64:
   case R_WASM_MEMORY_ADDR_SLEB64:
   case R_WASM_MEMORY_ADDR_SLEB:
   case R_WASM_MEMORY_ADDR_REL_SLEB:
   case R_WASM_MEMORY_ADDR_REL_SLEB64:
   case R_WASM_MEMORY_ADDR_I32:
   case R_WASM_MEMORY_ADDR_I64:
   case R_WASM_FUNCTION_OFFSET_I32:
+  case R_WASM_FUNCTION_OFFSET_I64:
     return reloc.Addend;
   case R_WASM_SECTION_OFFSET_I32:
     return getSectionSymbol(reloc.Index)->section->outputOffset + reloc.Addend;
   default:
     llvm_unreachable("unexpected relocation type");
   }
 }
 
if (segment.Data.Offset.Opcode == WASM_OPCODE_I32_CONST)
       return segment.Data.Offset.Value.Int32 + sym.Info.DataRef.Offset +
              reloc.Addend;
     else if (segment.Data.Offset.Opcode == WASM_OPCODE_I64_CONST)
       return segment.Data.Offset.Value.Int64 + sym.Info.DataRef.Offset +
              reloc.Addend;
     else
       llvm_unreachable("unknown init expr opcode");
   }
-  case R_WASM_FUNCTION_OFFSET_I32: {
+  case R_WASM_FUNCTION_OFFSET_I32:
+  case R_WASM_FUNCTION_OFFSET_I64: {
     const WasmSymbol &sym = wasmObj->syms()[reloc.Index];
     InputFunction *f =
         functions[sym.Info.ElementIndex - wasmObj->getNumImportedFunctions()];
     return f->getFunctionInputOffset() + f->getFunctionCodeOffset() +
            reloc.Addend;
   }
   case R_WASM_SECTION_OFFSET_I32:
     return reloc.Addend;
case R_WASM_FUNCTION_INDEX_LEB:
     return getFunctionSymbol(reloc.Index)->getFunctionIndex();
   case R_WASM_GLOBAL_INDEX_LEB:
   case R_WASM_GLOBAL_INDEX_I32:
     if (auto gs = dyn_cast<GlobalSymbol>(sym))
       return gs->getGlobalIndex();
     return sym->getGOTIndex();
   case R_WASM_EVENT_INDEX_LEB:
     return getEventSymbol(reloc.Index)->getEventIndex();
-  case R_WASM_FUNCTION_OFFSET_I32: {
+  case R_WASM_FUNCTION_OFFSET_I32:
+  case R_WASM_FUNCTION_OFFSET_I64: {
     auto *f = cast<DefinedFunction>(sym);
     return f->function->outputOffset +
            (f->function->getFunctionCodeOffset() + reloc.Addend);
   }
   case R_WASM_SECTION_OFFSET_I32:
     return getSectionSymbol(reloc.Index)->section->outputOffset + reloc.Addend;
   default:
     llvm_unreachable("unknown relocation type");

llvm/include/llvm/BinaryFormat/WasmRelocs.def

 WASM_RELOC(R_WASM_MEMORY_ADDR_LEB64,      14)
 WASM_RELOC(R_WASM_MEMORY_ADDR_SLEB64,     15)
 WASM_RELOC(R_WASM_MEMORY_ADDR_I64,        16)
 WASM_RELOC(R_WASM_MEMORY_ADDR_REL_SLEB64, 17)
 WASM_RELOC(R_WASM_TABLE_INDEX_SLEB64,     18)
 WASM_RELOC(R_WASM_TABLE_INDEX_I64,        19)
 WASM_RELOC(R_WASM_TABLE_NUMBER_LEB,       20)
 WASM_RELOC(R_WASM_MEMORY_ADDR_TLS_SLEB,   21)
+WASM_RELOC(R_WASM_FUNCTION_OFFSET_I64,    22)

llvm/lib/BinaryFormat/Wasm.cpp

bool llvm::wasm::relocTypeHasAddend(uint32_t Type) {
   case R_WASM_MEMORY_ADDR_SLEB:
   case R_WASM_MEMORY_ADDR_SLEB64:
   case R_WASM_MEMORY_ADDR_REL_SLEB:
   case R_WASM_MEMORY_ADDR_REL_SLEB64:
   case R_WASM_MEMORY_ADDR_I32:
   case R_WASM_MEMORY_ADDR_I64:
   case R_WASM_MEMORY_ADDR_TLS_SLEB:
   case R_WASM_FUNCTION_OFFSET_I32:
+  case R_WASM_FUNCTION_OFFSET_I64:
   case R_WASM_SECTION_OFFSET_I32:
     return true;
   default:
     return false;
   }
 }

llvm/lib/MC/WasmObjectWriter.cpp

void WasmObjectWriter::recordRelocation(MCAssembler &Asm,
   FixedValue = 0;
 
   unsigned Type = TargetObjectWriter->getRelocType(Target, Fixup);
 
   // Absolute offset within a section or a function.
   // Currently only supported for for metadata sections.
   // See: test/MC/WebAssembly/blockaddress.ll
   if (Type == wasm::R_WASM_FUNCTION_OFFSET_I32 ||
+      Type == wasm::R_WASM_FUNCTION_OFFSET_I64 ||
       Type == wasm::R_WASM_SECTION_OFFSET_I32) {
     if (!FixupSection.getKind().isMetadata())
       report_fatal_error("relocations for function or section offsets are "
                          "only supported in metadata sections");
 
     const MCSymbol *SectionSymbol = nullptr;
     const MCSection &SecA = SymA->getSection();
     if (SecA.getKind().isText())
WasmObjectWriter::getProvisionalValue(const WasmRelocationEntry &RelEntry,
   case wasm::R_WASM_GLOBAL_INDEX_LEB:
   case wasm::R_WASM_GLOBAL_INDEX_I32:
   case wasm::R_WASM_EVENT_INDEX_LEB:
   case wasm::R_WASM_TABLE_NUMBER_LEB:
     // Provisional value is function/global/event Wasm index
     assert(WasmIndices.count(RelEntry.Symbol) > 0 && "symbol not found in wasm index space");
     return WasmIndices[RelEntry.Symbol];
   case wasm::R_WASM_FUNCTION_OFFSET_I32:
+  case wasm::R_WASM_FUNCTION_OFFSET_I64:
   case wasm::R_WASM_SECTION_OFFSET_I32: {
     const auto &Section =
         static_cast<const MCSectionWasm &>(RelEntry.Symbol->getSection());
     return Section.getSectionOffset() + RelEntry.Addend;
   }
   case wasm::R_WASM_MEMORY_ADDR_LEB:
   case wasm::R_WASM_MEMORY_ADDR_LEB64:
   case wasm::R_WASM_MEMORY_ADDR_SLEB:
for (const WasmRelocationEntry &RelEntry : Relocations) {
     case wasm::R_WASM_MEMORY_ADDR_I32:
     case wasm::R_WASM_FUNCTION_OFFSET_I32:
     case wasm::R_WASM_SECTION_OFFSET_I32:
     case wasm::R_WASM_GLOBAL_INDEX_I32:
       patchI32(Stream, Value, Offset);
       break;
     case wasm::R_WASM_TABLE_INDEX_I64:
     case wasm::R_WASM_MEMORY_ADDR_I64:
+    case wasm::R_WASM_FUNCTION_OFFSET_I64:
       patchI64(Stream, Value, Offset);
       break;
     case wasm::R_WASM_TABLE_INDEX_SLEB:
     case wasm::R_WASM_TABLE_INDEX_REL_SLEB:
     case wasm::R_WASM_MEMORY_ADDR_SLEB:
     case wasm::R_WASM_MEMORY_ADDR_REL_SLEB:
     case wasm::R_WASM_MEMORY_ADDR_TLS_SLEB:
       writePatchableSLEB<5>(Stream, Value, Offset);

llvm/lib/Object/RelocationResolver.cpp

 
 static bool supportsWasm64(uint64_t Type) {
   switch (Type) {
   case wasm::R_WASM_MEMORY_ADDR_LEB64:
   case wasm::R_WASM_MEMORY_ADDR_SLEB64:
   case wasm::R_WASM_MEMORY_ADDR_I64:
   case wasm::R_WASM_TABLE_INDEX_SLEB64:
   case wasm::R_WASM_TABLE_INDEX_I64:
+  case wasm::R_WASM_FUNCTION_OFFSET_I64:
     return true;
   default:
     return supportsWasm32(Type);
   }
 }
 
 static uint64_t resolveWasm32(RelocationRef R, uint64_t S, uint64_t A) {
   switch (R.getType()) {

 
 static uint64_t resolveWasm64(RelocationRef R, uint64_t S, uint64_t A) {
   switch (R.getType()) {
   case wasm::R_WASM_MEMORY_ADDR_LEB64:
   case wasm::R_WASM_MEMORY_ADDR_SLEB64:
   case wasm::R_WASM_MEMORY_ADDR_I64:
   case wasm::R_WASM_TABLE_INDEX_SLEB64:
   case wasm::R_WASM_TABLE_INDEX_I64:
+  case wasm::R_WASM_FUNCTION_OFFSET_I64:
     // For wasm section, its offset at 0 -- ignoring Value
     return A;
   default:
     return resolveWasm32(R, S, A);
   }
 }
 
 std::pair<bool (*)(uint64_t), RelocationResolver>

llvm/lib/Object/WasmObjectFile.cpp

case wasm::R_WASM_MEMORY_ADDR_REL_SLEB64:
       Reloc.Addend = readVarint64(Ctx);
       break;
     case wasm::R_WASM_FUNCTION_OFFSET_I32:
       if (!isValidFunctionSymbol(Reloc.Index))
         return make_error<GenericBinaryError>("Bad relocation function index",
                                               object_error::parse_failed);
       Reloc.Addend = readVarint32(Ctx);
       break;
+    case wasm::R_WASM_FUNCTION_OFFSET_I64:
+      if (!isValidFunctionSymbol(Reloc.Index))
+        return make_error<GenericBinaryError>("Bad relocation function index",
+                                              object_error::parse_failed);
+      Reloc.Addend = readVarint64(Ctx);
+      break;
     case wasm::R_WASM_SECTION_OFFSET_I32:
       if (!isValidSectionSymbol(Reloc.Index))
         return make_error<GenericBinaryError>("Bad relocation section index",
                                               object_error::parse_failed);
       Reloc.Addend = readVarint32(Ctx);
       break;
     default:
       return make_error<GenericBinaryError>("Bad relocation type: " +
if (Reloc.Type == wasm::R_WASM_MEMORY_ADDR_LEB64 ||
       Size = 10;
     if (Reloc.Type == wasm::R_WASM_TABLE_INDEX_I32 ||
         Reloc.Type == wasm::R_WASM_MEMORY_ADDR_I32 ||
         Reloc.Type == wasm::R_WASM_SECTION_OFFSET_I32 ||
         Reloc.Type == wasm::R_WASM_FUNCTION_OFFSET_I32 ||
         Reloc.Type == wasm::R_WASM_GLOBAL_INDEX_I32)
       Size = 4;
     if (Reloc.Type == wasm::R_WASM_TABLE_INDEX_I64 ||
-        Reloc.Type == wasm::R_WASM_MEMORY_ADDR_I64)
+        Reloc.Type == wasm::R_WASM_MEMORY_ADDR_I64 ||
+        Reloc.Type == wasm::R_WASM_FUNCTION_OFFSET_I64)
       Size = 8;
     if (Reloc.Offset + Size > EndOffset)
       return make_error<GenericBinaryError>("Bad relocation offset",
                                             object_error::parse_failed);
 
     Section.Relocations.push_back(Reloc);
   }
   if (Ctx.Ptr != Ctx.End)

llvm/lib/ObjectYAML/WasmEmitter.cpp

for (auto Reloc : Sec.Relocations) {
     switch (Reloc.Type) {
     case wasm::R_WASM_MEMORY_ADDR_LEB:
     case wasm::R_WASM_MEMORY_ADDR_LEB64:
     case wasm::R_WASM_MEMORY_ADDR_SLEB:
     case wasm::R_WASM_MEMORY_ADDR_SLEB64:
     case wasm::R_WASM_MEMORY_ADDR_I32:
     case wasm::R_WASM_MEMORY_ADDR_I64:
     case wasm::R_WASM_FUNCTION_OFFSET_I32:
+    case wasm::R_WASM_FUNCTION_OFFSET_I64:
     case wasm::R_WASM_SECTION_OFFSET_I32:
       encodeULEB128(Reloc.Addend, OS);
     }
   }
 }
 
 bool WasmWriter::writeWasm(raw_ostream &OS) {
   // Write headers

llvm/lib/Target/WebAssembly/MCTargetDesc/WebAssemblyMCAsmInfo.cpp

 using namespace llvm;
 
 #define DEBUG_TYPE "wasm-mc-asm-info"
 
 WebAssemblyMCAsmInfo::~WebAssemblyMCAsmInfo() = default; // anchor.
 
 WebAssemblyMCAsmInfo::WebAssemblyMCAsmInfo(const Triple &T,
                                            const MCTargetOptions &Options) {
-  CalleeSaveStackSlotSize = T.isArch64Bit() ? 8 : 4;
-  // So far this is used for DWARF DW_AT_low_pc which is always 32-bit in Wasm.
-  CodePointerSize = 4;
+  CodePointerSize = CalleeSaveStackSlotSize = T.isArch64Bit() ? 8 : 4;
 
   // TODO: What should MaxInstLength be?
 
   UseDataRegionDirectives = true;
 
   // Use .skip instead of .zero because .zero is confusing when used with two
   // arguments (it doesn't actually zero things out).
   ZeroDirective = "\t.skip\t";

llvm/lib/Target/WebAssembly/MCTargetDesc/WebAssemblyWasmObjectWriter.cpp

unsigned WebAssemblyWasmObjectWriter::getRelocType(const MCValue &Target,
   case FK_Data_8:
     if (SymA.isFunction())
       return wasm::R_WASM_TABLE_INDEX_I64;
     if (SymA.isGlobal())
       llvm_unreachable("unimplemented R_WASM_GLOBAL_INDEX_I64");
     if (auto Section = static_cast<const MCSectionWasm *>(
             getFixupSection(Fixup.getValue()))) {
       if (Section->getKind().isText())
-        llvm_unreachable("unimplemented R_WASM_FUNCTION_OFFSET_I64");
+        return wasm::R_WASM_FUNCTION_OFFSET_I64;
       else if (!Section->isWasmData())
         llvm_unreachable("unimplemented R_WASM_SECTION_OFFSET_I64");
     }
     assert(SymA.isData());
     return wasm::R_WASM_MEMORY_ADDR_I64;
   default:
     llvm_unreachable("unimplemented fixup kind");
   }
 }
 
 std::unique_ptr<MCObjectTargetWriter>
 llvm::createWebAssemblyWasmObjectWriter(bool Is64Bit, bool IsEmscripten) {
   return std::make_unique<WebAssemblyWasmObjectWriter>(Is64Bit, IsEmscripten);
 }

llvm/test/MC/WebAssembly/debug-info64.ll

+; RUN: llc -filetype=obj %s -o - | llvm-readobj -r -S --symbols - | FileCheck %s
+
+; CHECK:      Format: WASM
+; CHECK-NEXT: Arch: wasm64
+; CHECK-NEXT: AddressSize: 64bit
+; CHECK-NEXT: Sections [
+; CHECK-NEXT:   Section {
+; CHECK-NEXT:     Type: TYPE (0x1)
+; CHECK-NEXT:     Size: 4
+; CHECK-NEXT:     Offset: 8
+; CHECK-NEXT:   }
+; CHECK-NEXT:   Section {
+; CHECK-NEXT:     Type: IMPORT (0x2)
+; CHECK-NEXT:     Size: 81
+; CHECK-NEXT:     Offset: 18
+; CHECK-NEXT:   }
+; CHECK-NEXT:   Section {
+; CHECK-NEXT:     Type: FUNCTION (0x3)
+; CHECK-NEXT:     Size: 2
+; CHECK-NEXT:     Offset: 105
+; CHECK-NEXT:   }
+; CHECK-NEXT:   Section {
+; CHECK-NEXT:     Type: ELEM (0x9)
+; CHECK-NEXT:     Size: 7
+; CHECK-NEXT:     Offset: 113
+; CHECK-NEXT:   }
+; CHECK-NEXT:   Section {
+; CHECK-NEXT:     Type: DATACOUNT (0xC)
+; CHECK-NEXT:     Size: 1
+; CHECK-NEXT:     Offset: 126
+; CHECK-NEXT:   }
+; CHECK-NEXT:   Section {
+; CHECK-NEXT:     Type: CODE (0xA)
+; CHECK-NEXT:     Size: 4
+; CHECK-NEXT:     Offset: 133
+; CHECK-NEXT:   }
+; CHECK-NEXT:   Section {
+; CHECK-NEXT:     Type: DATA (0xB)
+; CHECK-NEXT:     Size: 27
+; CHECK-NEXT:     Offset: 143
+; CHECK-NEXT:     Segments [
+; CHECK-NEXT:       Segment {
+; CHECK-NEXT:         Name: .data.foo
+; CHECK-NEXT:         Size: 8
+; CHECK-NEXT:         Offset: 0
+; CHECK-NEXT:       }
+; CHECK-NEXT:       Segment {
+; CHECK-NEXT:         Name: .data.ptr2
+; CHECK-NEXT:         Size: 8
+; CHECK-NEXT:         Offset: 8
+; CHECK-NEXT:       }
+; CHECK-NEXT:     ]
+; CHECK-NEXT:   }
+; CHECK-NEXT:   Section {
+; CHECK-NEXT:     Type: CUSTOM (0x0)
+; CHECK-NEXT:     Size: 86
+; CHECK-NEXT:     Offset: 176
+; CHECK-NEXT:     Name: .debug_abbrev
+; CHECK-NEXT:   }
+; CHECK-NEXT:   Section {
+; CHECK-NEXT:     Type: CUSTOM (0x0)
+; CHECK-NEXT:     Size: 130
+; CHECK-NEXT:     Offset: 282
+; CHECK-NEXT:     Name: .debug_info
+; CHECK-NEXT:   }
+; CHECK-NEXT:   Section {
+; CHECK-NEXT:     Type: CUSTOM (0x0)
+; CHECK-NEXT:     Size: 121
+; CHECK-NEXT:     Offset: 430
+; CHECK-NEXT:     Name: .debug_str
+; CHECK-NEXT:   }
+; CHECK-NEXT:   Section {
+; CHECK-NEXT:     Type: CUSTOM (0x0)
+; CHECK-NEXT:     Size: 42
+; CHECK-NEXT:     Offset: 568
+; CHECK-NEXT:     Name: .debug_pubnames
+; CHECK-NEXT:   }
+; CHECK-NEXT:   Section {
+; CHECK-NEXT:     Type: CUSTOM (0x0)
+; CHECK-NEXT:     Size: 26
+; CHECK-NEXT:     Offset: 632
+; CHECK-NEXT:     Name: .debug_pubtypes
+; CHECK-NEXT:   }
+; CHECK-NEXT:   Section {
+; CHECK-NEXT:     Type: CUSTOM (0x0)
+; CHECK-NEXT:     Size: 61
+; CHECK-NEXT:     Offset: 680
+; CHECK-NEXT:     Name: .debug_line
+; CHECK-NEXT:   }
+; CHECK-NEXT:   Section {
+; CHECK-NEXT:     Type: CUSTOM (0x0)
+; CHECK-NEXT:     Size: 91
+; CHECK-NEXT:     Offset: 759
+; CHECK-NEXT:     Name: linking
+; CHECK-NEXT:   }
+; CHECK-NEXT:   Section {
+; CHECK-NEXT:     Type: CUSTOM (0x0)
+; CHECK-NEXT:     Size: 9
+; CHECK-NEXT:     Offset: 864
+; CHECK-NEXT:     Name: reloc.DATA
+; CHECK-NEXT:   }
+; CHECK-NEXT:   Section {
+; CHECK-NEXT:     Type: CUSTOM (0x0)
+; CHECK-NEXT:     Size: 61
+; CHECK-NEXT:     Offset: 890
+; CHECK-NEXT:     Name: reloc..debug_info
+; CHECK-NEXT:   }
+; CHECK-NEXT:   Section {
+; CHECK-NEXT:     Type: CUSTOM (0x0)
+; CHECK-NEXT:     Size: 6
+; CHECK-NEXT:     Offset: 975
+; CHECK-NEXT:     Name: reloc..debug_pubnames
+; CHECK-NEXT:   }
+; CHECK-NEXT:   Section {
+; CHECK-NEXT:     Type: CUSTOM (0x0)
+; CHECK-NEXT:     Size: 6
+; CHECK-NEXT:     Offset: 1009
+; CHECK-NEXT:     Name: reloc..debug_pubtypes
+; CHECK-NEXT:   }
+; CHECK-NEXT:   Section {
+; CHECK-NEXT:     Type: CUSTOM (0x0)
+; CHECK-NEXT:     Size: 6
+; CHECK-NEXT:     Offset: 1043
+; CHECK-NEXT:     Name: reloc..debug_line
+; CHECK-NEXT:   }
+; CHECK-NEXT:   Section {
+; CHECK-NEXT:     Type: CUSTOM (0x0)
+; CHECK-NEXT:     Size: 77
+; CHECK-NEXT:     Offset: 1073
+; CHECK-NEXT:     Name: producers
+; CHECK-NEXT:   }
+; CHECK-NEXT: ]
+; CHECK-NEXT: Relocations [
+; CHECK-NEXT:   Section (7) DATA {
+; CHECK-NEXT:     0x6 R_WASM_MEMORY_ADDR_I64 myextern 0
+; CHECK-NEXT:     0x13 R_WASM_TABLE_INDEX_I64 f2
+; CHECK-NEXT:   }
+; CHECK-NEXT:   Section (9) .debug_info {
+; CHECK-NEXT:     0x6 R_WASM_SECTION_OFFSET_I32 .debug_abbrev 0
+; CHECK-NEXT:     0xC R_WASM_SECTION_OFFSET_I32 .debug_str 0
+; CHECK-NEXT:     0x12 R_WASM_SECTION_OFFSET_I32 .debug_str 55
+; CHECK-NEXT:     0x16 R_WASM_SECTION_OFFSET_I32 .debug_line 0
+; CHECK-NEXT:     0x1A R_WASM_SECTION_OFFSET_I32 .debug_str 62
+; CHECK-NEXT:     0x1E R_WASM_FUNCTION_OFFSET_I64 f2 0
+; CHECK-NEXT:     0x2B R_WASM_SECTION_OFFSET_I32 .debug_str 105
+; CHECK-NEXT:     0x37 R_WASM_MEMORY_ADDR_I64 foo 0
+; CHECK-NEXT:     0x45 R_WASM_SECTION_OFFSET_I32 .debug_str 109
+; CHECK-NEXT:     0x4C R_WASM_SECTION_OFFSET_I32 .debug_str 113
+; CHECK-NEXT:     0x58 R_WASM_MEMORY_ADDR_I64 ptr2 0
+; CHECK-NEXT:     0x67 R_WASM_FUNCTION_OFFSET_I64 f2 0
+; CHECK-NEXT:     0x76 R_WASM_GLOBAL_INDEX_I32 __stack_pointer
+; CHECK-NEXT:     0x7B R_WASM_SECTION_OFFSET_I32 .debug_str 118
+; CHECK-NEXT:   }
+; CHECK-NEXT:   Section (11) .debug_pubnames {
+; CHECK-NEXT:     0x6 R_WASM_SECTION_OFFSET_I32 .debug_info 0
+; CHECK-NEXT:   }
+; CHECK-NEXT:   Section (12) .debug_pubtypes {
+; CHECK-NEXT:     0x6 R_WASM_SECTION_OFFSET_I32 .debug_info 0
+; CHECK-NEXT:   }
+; CHECK-NEXT:   Section (13) .debug_line {
+; CHECK-NEXT:     0x2B R_WASM_FUNCTION_OFFSET_I64 f2 0
+; CHECK-NEXT:   }
+; CHECK-NEXT: ]
+; CHECK-NEXT: Symbols [
+; CHECK-NEXT:   Symbol {
+; CHECK-NEXT:     Name: f2
+; CHECK-NEXT:     Type: FUNCTION (0x0)
+; CHECK-NEXT:     Flags [ (0x4)
+; CHECK-NEXT:       VISIBILITY_HIDDEN (0x4)
+; CHECK-NEXT:     ]
+; CHECK-NEXT:     ElementIndex: 0x0
+; CHECK-NEXT:   }
+; CHECK-NEXT:   Symbol {
+; CHECK-NEXT:     Name: foo
+; CHECK-NEXT:     Type: DATA (0x1)
+; CHECK-NEXT:     Flags [ (0x4)
+; CHECK-NEXT:       VISIBILITY_HIDDEN (0x4)
+; CHECK-NEXT:     ]
+; CHECK-NEXT:     Offset: 0x0
+; CHECK-NEXT:     Segment: 0x0
+; CHECK-NEXT:     Size: 0x8
+; CHECK-NEXT:   }
+; CHECK-NEXT:   Symbol {
+; CHECK-NEXT:     Name: myextern
+; CHECK-NEXT:     Type: DATA (0x1)
+; CHECK-NEXT:     Flags [ (0x10)
+; CHECK-NEXT:       UNDEFINED (0x10)
+; CHECK-NEXT:     ]
+; CHECK-NEXT:   }
+; CHECK-NEXT:   Symbol {
+; CHECK-NEXT:     Name: ptr2
+; CHECK-NEXT:     Type: DATA (0x1)
+; CHECK-NEXT:     Flags [ (0x4)
+; CHECK-NEXT:       VISIBILITY_HIDDEN (0x4)
+; CHECK-NEXT:     ]
+; CHECK-NEXT:     Offset: 0x0
+; CHECK-NEXT:     Segment: 0x1
+; CHECK-NEXT:     Size: 0x8
+; CHECK-NEXT:   }
+; CHECK-NEXT:   Symbol {
+; CHECK-NEXT:     Name: .debug_abbrev
+; CHECK-NEXT:     Type: SECTION (0x3)
+; CHECK-NEXT:     Flags [ (0x2)
+; CHECK-NEXT:       BINDING_LOCAL (0x2)
+; CHECK-NEXT:     ]
+; CHECK-NEXT:     ElementIndex: 0x7
+; CHECK-NEXT:   }
+; CHECK-NEXT:   Symbol {
+; CHECK-NEXT:     Name: .debug_info
+; CHECK-NEXT:     Type: SECTION (0x3)
+; CHECK-NEXT:     Flags [ (0x2)
+; CHECK-NEXT:       BINDING_LOCAL (0x2)
+; CHECK-NEXT:     ]
+; CHECK-NEXT:     ElementIndex: 0x8
+; CHECK-NEXT:   }
+; CHECK-NEXT:   Symbol {
+; CHECK-NEXT:     Name: __stack_pointer
+; CHECK-NEXT:     Type: GLOBAL (0x2)
+; CHECK-NEXT:     Flags [ (0x10)
+; CHECK-NEXT:       UNDEFINED (0x10)
+; CHECK-NEXT:     ]
+; CHECK-NEXT:     ImportName: __stack_pointer
+; CHECK-NEXT:     ImportModule: env
+; CHECK-NEXT:     ElementIndex: 0x0
+; CHECK-NEXT:   }
+; CHECK-NEXT:   Symbol {
+; CHECK-NEXT:     Name: .debug_str
+; CHECK-NEXT:     Type: SECTION (0x3)
+; CHECK-NEXT:     Flags [ (0x2)
+; CHECK-NEXT:       BINDING_LOCAL (0x2)
+; CHECK-NEXT:     ]
+; CHECK-NEXT:     ElementIndex: 0x9
+; CHECK-NEXT:   }
+; CHECK-NEXT:   Symbol {
+; CHECK-NEXT:     Name: .debug_line
+; CHECK-NEXT:     Type: SECTION (0x3)
+; CHECK-NEXT:     Flags [ (0x2)
+; CHECK-NEXT:       BINDING_LOCAL (0x2)
+; CHECK-NEXT:     ]
+; CHECK-NEXT:     ElementIndex: 0xC
+; CHECK-NEXT:   }
+; CHECK-NEXT: ]
+
+; generated from the following C code using: clang --target=wasm64 -g -O0 -S -emit-llvm test.c
+; extern int myextern;
+; void f2(void) { return; }
+;
+; int* foo = &myextern;
+; void (*ptr2)(void) = f2;
+
+target triple = "wasm64-unknown-unknown"
+
+source_filename = "test.c"
+
+@myextern = external global i32, align 4
+@foo = hidden global i32* @myextern, align 4, !dbg !0
+@ptr2 = hidden global void ()* @f2, align 4, !dbg !6
+
+; Function Attrs: noinline nounwind optnone
+define hidden void @f2() #0 !dbg !17 {
+entry:
+  ret void, !dbg !18
+}
+
+attributes #0 = { noinline nounwind optnone "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "less-precise-fpmad"="false" "frame-pointer"="none" "no-infs-fp-math"="false" "no-jump-tables"="false" "no-nans-fp-math"="false" "no-signed-zeros-fp-math"="false" "no-trapping-math"="false" "stack-protector-buffer-size"="8" "target-cpu"="generic" "unsafe-fp-math"="false" "use-soft-float"="false" }
+
+!llvm.dbg.cu = !{!2}
+!llvm.module.flags = !{!13, !14, !15}
+!llvm.ident = !{!16}
+
+!0 = !DIGlobalVariableExpression(var: !1, expr: !DIExpression())
+!1 = distinct !DIGlobalVariable(name: "foo", scope: !2, file: !3, line: 4, type: !11, isLocal: false, isDefinition: true)
+!2 = distinct !DICompileUnit(language: DW_LANG_C99, file: !3, producer: "clang version 7.0.0 (trunk 332303) (llvm/trunk 332406)", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug, enums: !4, globals: !5)
+!3 = !DIFile(filename: "test.c", directory: "/usr/local/google/home/sbc/dev/wasm/simple")
+!4 = !{}
+!5 = !{!0, !6}
+!6 = !DIGlobalVariableExpression(var: !7, expr: !DIExpression())
+!7 = distinct !DIGlobalVariable(name: "ptr2", scope: !2, file: !3, line: 5, type: !8, isLocal: false, isDefinition: true)
+!8 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !9, size: 32)
+!9 = !DISubroutineType(types: !10)
+!10 = !{null}
+!11 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !12, size: 32)
+!12 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+!13 = !{i32 2, !"Dwarf Version", i32 4}
+!14 = !{i32 2, !"Debug Info Version", i32 3}
+!15 = !{i32 1, !"wchar_size", i32 4}
+!16 = !{!"clang version 7.0.0 (trunk 332303) (llvm/trunk 332406)"}
+!17 = distinct !DISubprogram(name: "f2", scope: !3, file: !3, line: 2, type: !9, isLocal: false, isDefinition: true, scopeLine: 2, flags: DIFlagPrototyped, isOptimized: false, unit: !2, retainedNodes: !4)
+!18 = !DILocation(line: 2, column: 17, scope: !17)

llvm/test/MC/WebAssembly/dwarfdump64.ll

 ; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
 ; RUN: llc -filetype=obj %s -o - | llvm-dwarfdump --show-form - | FileCheck %s
 
 ; CHECK: .debug_info contents:
-; CHECK-NEXT: 0x00000000: Compile Unit: length = 0x0000006e, format = DWARF32, version = 0x0004, abbr_offset = 0x0000, addr_size = 0x04 (next unit at 0x00000072)
+; CHECK-NEXT: 0x00000000: Compile Unit: length = 0x0000007e, format = DWARF32, version = 0x0004, abbr_offset = 0x0000, addr_size = 0x08 (next unit at 0x00000082)
 
 ; CHECK: 0x0000000b: DW_TAG_compile_unit
 ; CHECK-NEXT:              DW_AT_producer [DW_FORM_strp]     ("clang version 6.0.0 (trunk 315924) (llvm/trunk 315960)")
 ; CHECK-NEXT:              DW_AT_language [DW_FORM_data2]    (DW_LANG_C99)
 ; CHECK-NEXT:              DW_AT_name [DW_FORM_strp] ("test.c")
 ; CHECK-NEXT:              DW_AT_stmt_list [DW_FORM_sec_offset]      (0x00000000)
 ; CHECK-NEXT:              DW_AT_comp_dir [DW_FORM_strp]     ("/usr/local/google/home/sbc/dev/wasm/simple")
 ; CHECK-NEXT:              DW_AT_GNU_pubnames [DW_FORM_flag_present] (true)
-; CHECK-NEXT:              DW_AT_low_pc [DW_FORM_addr]       (0x00000002)
+; CHECK-NEXT:              DW_AT_low_pc [DW_FORM_addr]       (0x0000000000000002)
 ; CHECK-NEXT:              DW_AT_high_pc [DW_FORM_data4]     (0x00000002)
 
-; CHECK: 0x00000026:   DW_TAG_variable
+; CHECK: 0x0000002a:   DW_TAG_variable
 ; CHECK-NEXT:                DW_AT_name [DW_FORM_strp]       ("foo")
-; CHECK-NEXT:                DW_AT_type [DW_FORM_ref4]       (0x00000037 "int*")
+; CHECK-NEXT:                DW_AT_type [DW_FORM_ref4]       (0x0000003f "int*")
 ; CHECK-NEXT:                DW_AT_external [DW_FORM_flag_present]   (true)
 ; CHECK-NEXT:                DW_AT_decl_file [DW_FORM_data1] ("/usr/local/google/home/sbc/dev/wasm/simple{{[/\\]}}test.c")
 ; CHECK-NEXT:                DW_AT_decl_line [DW_FORM_data1] (4)
 ; CHECK-NEXT:                DW_AT_location [DW_FORM_exprloc]        (DW_OP_addr 0x0)
 
-; CHECK: 0x00000037:   DW_TAG_pointer_type
-; CHECK-NEXT:                DW_AT_type [DW_FORM_ref4]  (0x0000003c "int")
+; CHECK: 0x0000003f:   DW_TAG_pointer_type
+; CHECK-NEXT:                DW_AT_type [DW_FORM_ref4]       (0x00000044 "int")
 
-; CHECK: 0x0000003c:   DW_TAG_base_type
+; CHECK: 0x00000044:   DW_TAG_base_type
 ; CHECK-NEXT:                DW_AT_name [DW_FORM_strp]       ("int")
 ; CHECK-NEXT:                DW_AT_encoding [DW_FORM_data1]  (DW_ATE_signed)
 ; CHECK-NEXT:                DW_AT_byte_size [DW_FORM_data1] (0x04)
 
-; CHECK: 0x00000043:   DW_TAG_variable
+; CHECK: 0x0000004b:   DW_TAG_variable
 ; CHECK-NEXT:                DW_AT_name [DW_FORM_strp]       ("ptr2")
-; CHECK-NEXT:                DW_AT_type [DW_FORM_ref4]       (0x00000054 "void()*")
+; CHECK-NEXT:                DW_AT_type [DW_FORM_ref4]       (0x00000060 "void()*")
 ; CHECK-NEXT:                DW_AT_external [DW_FORM_flag_present]   (true)
 ; CHECK-NEXT:                DW_AT_decl_file [DW_FORM_data1] ("/usr/local/google/home/sbc/dev/wasm/simple{{[/\\]}}test.c")
 ; CHECK-NEXT:                DW_AT_decl_line [DW_FORM_data1] (5)
-
-
-
-; TODO: is this correct?
-
 ; CHECK-NEXT:                DW_AT_location [DW_FORM_exprloc]        (DW_OP_addr 0x8)
 
-; CHECK: 0x00000054:   DW_TAG_pointer_type
-; CHECK-NEXT:                DW_AT_type [DW_FORM_ref4]  (0x00000059 "void()")
+; CHECK: 0x00000060:   DW_TAG_pointer_type
+; CHECK-NEXT:                DW_AT_type [DW_FORM_ref4]       (0x00000065 "void()")
 
-; CHECK: 0x00000059:   DW_TAG_subroutine_type
-; CHECK-NEXT:                DW_AT_prototyped [DW_FORM_flag_present]  (true)
+; CHECK: 0x00000065:   DW_TAG_subroutine_type
+; CHECK-NEXT:                DW_AT_prototyped [DW_FORM_flag_present] (true)
 
-; CHECK: 0x0000005a:   DW_TAG_subprogram
-; CHECK-NEXT:                DW_AT_low_pc [DW_FORM_addr]     (0x00000002)
+; CHECK: 0x00000066:   DW_TAG_subprogram
+; CHECK-NEXT:                DW_AT_low_pc [DW_FORM_addr]     (0x0000000000000002)
 ; CHECK-NEXT:                DW_AT_high_pc [DW_FORM_data4]   (0x00000002)
 ; CHECK-NEXT:                DW_AT_frame_base [DW_FORM_exprloc]      (DW_OP_WASM_location 0x3 0x0, DW_OP_stack_value)
 ; CHECK-NEXT:                DW_AT_name [DW_FORM_strp]       ("f2")
 ; CHECK-NEXT:                DW_AT_decl_file [DW_FORM_data1] ("/usr/local/google/home/sbc/dev/wasm/simple{{[/\\]}}test.c")
 ; CHECK-NEXT:                DW_AT_decl_line [DW_FORM_data1] (2)
 ; CHECK-NEXT:                DW_AT_prototyped [DW_FORM_flag_present] (true)
 ; CHECK-NEXT:                DW_AT_external [DW_FORM_flag_present]   (true)
 
-; CHECK: 0x00000071:   NULL
+; CHECK: 0x00000081:   NULL
 
 target triple = "wasm64-unknown-unknown"
 
 source_filename = "test.c"
 
 @myextern = external global i32, align 4
 @foo = hidden global i32* @myextern, align 4, !dbg !0
 @ptr2 = hidden global void ()* @f2, align 4, !dbg !6