[WebAssembly] Add wasm symbol table support to llvm-objdump

[dschuff]

lib/Object/WasmObjectFile.cpp

672

Do we need the extra return as we had before, for non-asserts builds?

[sbc100]

• Store index values in WasmSymbol

[sbc100]

• cleanup getSymbolFlags

[sbc100]

lib/Object/WasmObjectFile.cpp

672

I cleaned this up to me more like the other object format.

[sbc100]

• Add missing breaks

include/llvm/Object/Wasm.h

public:
   enum class SymbolType {
     FUNCTION_IMPORT,
     FUNCTION_EXPORT,
     GLOBAL_IMPORT,
     GLOBAL_EXPORT,
     DEBUG_FUNCTION_NAME,
   };
 
-  WasmSymbol(StringRef Name, SymbolType Type) : Name(Name), Type(Type) {}
+  WasmSymbol(StringRef Name, SymbolType Type, uint32_t SectionIndex)
+      : Name(Name), Type(Type), SectionIndex(SectionIndex) {}
 
   StringRef Name;
   SymbolType Type;
+  uint32_t SectionIndex;
 };
 
 class WasmSection {
 public:
   WasmSection() = default;
 
   uint32_t Type = 0; // Section type (See below)
   uint32_t Offset = 0; // Offset with in the file

lib/Object/WasmObjectFile.cpp

while (Ptr < End) {
     switch (Type) {
     case wasm::WASM_NAMES_FUNCTION: {
       uint32_t Count = readVaruint32(Ptr);
       while (Count--) {
         /*uint32_t Index =*/readVaruint32(Ptr);
         StringRef Name = readString(Ptr);
         if (!Name.empty())
           Symbols.emplace_back(Name,
-                               WasmSymbol::SymbolType::DEBUG_FUNCTION_NAME);
+                               WasmSymbol::SymbolType::DEBUG_FUNCTION_NAME,
+                               Sections.size());
       }
       break;
     }
     // Ignore local names for now
     case wasm::WASM_NAMES_LOCAL:
     default:
       Ptr += Size;
       break;
Error WasmObjectFile::parseImportSection(const uint8_t *Ptr, const uint8_t *End) {
   while (Count--) {
     wasm::WasmImport Im;
     Im.Module = readString(Ptr);
     Im.Field = readString(Ptr);
     Im.Kind = readUint8(Ptr);
     switch (Im.Kind) {
     case wasm::WASM_EXTERNAL_FUNCTION:
       Im.SigIndex = readVaruint32(Ptr);
-      Symbols.emplace_back(Im.Field, WasmSymbol::SymbolType::FUNCTION_IMPORT);
+      Symbols.emplace_back(Im.Field, WasmSymbol::SymbolType::FUNCTION_IMPORT,
+                           Sections.size());
       break;
     case wasm::WASM_EXTERNAL_GLOBAL:
       Im.GlobalType = readVarint7(Ptr);
       Im.GlobalMutable = readVaruint1(Ptr);
-      Symbols.emplace_back(Im.Field, WasmSymbol::SymbolType::GLOBAL_IMPORT);
+      Symbols.emplace_back(Im.Field, WasmSymbol::SymbolType::GLOBAL_IMPORT,
+                           Sections.size());
       break;
     default:
       // TODO(sbc): Handle other kinds of imports
       return make_error<GenericBinaryError>(
           "Unexpected import kind", object_error::parse_failed);
     }
     Imports.push_back(Im);
   }
Error WasmObjectFile::parseExportSection(const uint8_t *Ptr, const uint8_t *End) {
   while (Count--) {
     wasm::WasmExport Ex;
     Ex.Name = readString(Ptr);
     Ex.Kind = readUint8(Ptr);
     Ex.Index = readVaruint32(Ptr);
     Exports.push_back(Ex);
     switch (Ex.Kind) {
     case wasm::WASM_EXTERNAL_FUNCTION:
-      Symbols.emplace_back(Ex.Name, WasmSymbol::SymbolType::FUNCTION_EXPORT);
+      Symbols.emplace_back(Ex.Name, WasmSymbol::SymbolType::FUNCTION_EXPORT,
+                           Sections.size());
       break;
     case wasm::WASM_EXTERNAL_GLOBAL:
-      Symbols.emplace_back(Ex.Name, WasmSymbol::SymbolType::GLOBAL_EXPORT);
+      Symbols.emplace_back(Ex.Name, WasmSymbol::SymbolType::GLOBAL_EXPORT,
+                           Sections.size());
       break;
     default:
       // TODO(sbc): Handle other kinds of exports
       return make_error<GenericBinaryError>(
           "Unexpected export kind", object_error::parse_failed);
     }
   }
   if (Ptr != End)

 
 uint64_t WasmObjectFile::getCommonSymbolSizeImpl(DataRefImpl Symb) const {
   llvm_unreachable("not yet implemented");
   return 0;
 }
 
 Expected<SymbolRef::Type>
 WasmObjectFile::getSymbolType(DataRefImpl Symb) const {
-  llvm_unreachable("not yet implemented");
-  return errorCodeToError(object_error::invalid_symbol_index);
+  switch (Symbols[Symb.d.a].Type) {
+  case WasmSymbol::SymbolType::FUNCTION_IMPORT:
+  case WasmSymbol::SymbolType::FUNCTION_EXPORT:
+  case WasmSymbol::SymbolType::DEBUG_FUNCTION_NAME:
+    return object::SymbolRef::ST_Function;
+  case WasmSymbol::SymbolType::GLOBAL_IMPORT:
+  case WasmSymbol::SymbolType::GLOBAL_EXPORT:
+    return object::SymbolRef::ST_Data;
+  }
+  llvm_unreachable("Unknown WasmSymbol::SymbolType");
 }
 
 Expected<section_iterator>
 WasmObjectFile::getSymbolSection(DataRefImpl Symb) const {
-  llvm_unreachable("not yet implemented");
-  return errorCodeToError(object_error::invalid_symbol_index);
+  DataRefImpl Ref;
+  Ref.d.a = getWasmSymbol(Symb).SectionIndex;
+  return section_iterator(SectionRef(Ref, this));
 }
 
 void WasmObjectFile::moveSectionNext(DataRefImpl &Sec) const { Sec.d.a++; }
 
 std::error_code WasmObjectFile::getSectionName(DataRefImpl Sec,
                                                StringRef &Res) const {
   const WasmSection &S = Sections[Sec.d.a];
 #define ECase(X)                                                               \

test/tools/llvm-objdump/WebAssembly/symbol-table.test

+RUN: llvm-objdump -t %p/../Inputs/test.wasm | FileCheck %s
+
+CHECK: SYMBOL TABLE:
+CHECK: 00000000 l     F IMPORT bar
+CHECK: 00000001 g     F EXPORT baz
+CHECK: 00000002 g     F EXPORT quux
+CHECK: 00000003 l     F name   $import
+CHECK: 00000004 l     F name   $func0