tools/llvm-readobj/WasmDumper.cpp

   1 //===-- WasmDumper.cpp - Wasm-specific object file dumper -----------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 //
   9 // This file implements the Wasm-specific dumper for llvm-readobj.
  10 //
  11 //===----------------------------------------------------------------------===//
  12
  13 #include "Error.h"
  14 #include "ObjDumper.h"
  15 #include "llvm-readobj.h"
  16 #include "llvm/Object/Wasm.h"
  17 #include "llvm/Support/ScopedPrinter.h"
  18
  19 using namespace llvm;
  20 using namespace object;
  21
  22 namespace {
  23
  24 static const EnumEntry<unsigned> WasmSymbolTypes[] = {
  25 #define ENUM_ENTRY(X)                                                          \
  26   { #X, wasm::WASM_SYMBOL_TYPE_##X }
  27     ENUM_ENTRY(FUNCTION), ENUM_ENTRY(DATA),  ENUM_ENTRY(GLOBAL),
  28     ENUM_ENTRY(SECTION),  ENUM_ENTRY(EVENT),
  29 #undef ENUM_ENTRY
  30 };
  31
  32 static const EnumEntry<uint32_t> WasmSectionTypes[] = {
  33 #define ENUM_ENTRY(X)                                                          \
  34   { #X, wasm::WASM_SEC_##X }
  35     ENUM_ENTRY(CUSTOM),   ENUM_ENTRY(TYPE),      ENUM_ENTRY(IMPORT),
  36     ENUM_ENTRY(FUNCTION), ENUM_ENTRY(TABLE),     ENUM_ENTRY(MEMORY),
  37     ENUM_ENTRY(GLOBAL),   ENUM_ENTRY(EVENT),     ENUM_ENTRY(EXPORT),
  38     ENUM_ENTRY(START),    ENUM_ENTRY(ELEM),      ENUM_ENTRY(CODE),
  39     ENUM_ENTRY(DATA),     ENUM_ENTRY(DATACOUNT),
  40 #undef ENUM_ENTRY
  41 };
  42
  43 static const EnumEntry<unsigned> WasmSymbolFlags[] = {
  44 #define ENUM_ENTRY(X)                                                          \
  45   { #X, wasm::WASM_SYMBOL_##X }
  46   ENUM_ENTRY(BINDING_GLOBAL),
  47   ENUM_ENTRY(BINDING_WEAK),
  48   ENUM_ENTRY(BINDING_LOCAL),
  49   ENUM_ENTRY(VISIBILITY_DEFAULT),
  50   ENUM_ENTRY(VISIBILITY_HIDDEN),
  51   ENUM_ENTRY(UNDEFINED),
  52   ENUM_ENTRY(EXPORTED),
  53   ENUM_ENTRY(EXPLICIT_NAME),
  54   ENUM_ENTRY(NO_STRIP),
  55 #undef ENUM_ENTRY
  56 };
  57
  58 class WasmDumper : public ObjDumper {
  59 public:
  60   WasmDumper(const WasmObjectFile *Obj, ScopedPrinter &Writer)
  61       : ObjDumper(Writer), Obj(Obj) {}
  62
  63   void printFileHeaders() override;
  64   void printSectionHeaders() override;
  65   void printRelocations() override;
  66   void printUnwindInfo() override { llvm_unreachable("unimplemented"); }
  67   void printStackMap() const override { llvm_unreachable("unimplemented"); }
  68
  69 protected:
  70   void printSymbol(const SymbolRef &Sym);
  71   void printRelocation(const SectionRef &Section, const RelocationRef &Reloc);
  72
  73 private:
  74   void printSymbols() override;
  75   void printDynamicSymbols() override { llvm_unreachable("unimplemented"); }
  76
  77   const WasmObjectFile *Obj;
  78 };
  79
  80 void WasmDumper::printFileHeaders() {
  81   W.printHex("Version", Obj->getHeader().Version);
  82 }
  83
  84 void WasmDumper::printRelocation(const SectionRef &Section,
  85                                  const RelocationRef &Reloc) {
  86   SmallString<64> RelocTypeName;
  87   uint64_t RelocType = Reloc.getType();
  88   Reloc.getTypeName(RelocTypeName);
  89   const wasm::WasmRelocation &WasmReloc = Obj->getWasmRelocation(Reloc);
  90
  91   StringRef SymName;
  92   symbol_iterator SI = Reloc.getSymbol();
  93   if (SI != Obj->symbol_end())
  94     SymName = unwrapOrError(Obj->getFileName(), SI->getName());
  95
  96   bool HasAddend = false;
  97   switch (RelocType) {
  98   case wasm::R_WASM_MEMORY_ADDR_LEB:
  99   case wasm::R_WASM_MEMORY_ADDR_SLEB:
 100   case wasm::R_WASM_MEMORY_ADDR_I32:
 101   case wasm::R_WASM_FUNCTION_OFFSET_I32:
 102   case wasm::R_WASM_SECTION_OFFSET_I32:
 103     HasAddend = true;
 104     break;
 105   default:
 106     break;
 107   }
 108   if (opts::ExpandRelocs) {
 109     DictScope Group(W, "Relocation");
 110     W.printNumber("Type", RelocTypeName, RelocType);
 111     W.printHex("Offset", Reloc.getOffset());
 112     if (!SymName.empty())
 113       W.printString("Symbol", SymName);
 114     else
 115       W.printHex("Index", WasmReloc.Index);
 116     if (HasAddend)
 117       W.printNumber("Addend", WasmReloc.Addend);
 118   } else {
 119     raw_ostream &OS = W.startLine();
 120     OS << W.hex(Reloc.getOffset()) << " " << RelocTypeName << " ";
 121     if (!SymName.empty())
 122       OS << SymName;
 123     else
 124       OS << WasmReloc.Index;
 125     if (HasAddend)
 126       OS << " " << WasmReloc.Addend;
 127     OS << "\n";
 128   }
 129 }
 130
 131 void WasmDumper::printRelocations() {
 132   ListScope D(W, "Relocations");
 133
 134   int SectionNumber = 0;
 135   for (const SectionRef &Section : Obj->sections()) {
 136     bool PrintedGroup = false;
 137     StringRef Name = unwrapOrError(Obj->getFileName(), Section.getName());
 138
 139     ++SectionNumber;
 140
 141     for (const RelocationRef &Reloc : Section.relocations()) {
 142       if (!PrintedGroup) {
 143         W.startLine() << "Section (" << SectionNumber << ") " << Name << " {\n";
 144         W.indent();
 145         PrintedGroup = true;
 146       }
 147
 148       printRelocation(Section, Reloc);
 149     }
 150
 151     if (PrintedGroup) {
 152       W.unindent();
 153       W.startLine() << "}\n";
 154     }
 155   }
 156 }
 157
 158 void WasmDumper::printSymbols() {
 159   ListScope Group(W, "Symbols");
 160
 161   for (const SymbolRef &Symbol : Obj->symbols())
 162     printSymbol(Symbol);
 163 }
 164
 165 void WasmDumper::printSectionHeaders() {
 166   ListScope Group(W, "Sections");
 167   for (const SectionRef &Section : Obj->sections()) {
 168     const WasmSection &WasmSec = Obj->getWasmSection(Section);
 169     DictScope SectionD(W, "Section");
 170     W.printEnum("Type", WasmSec.Type, makeArrayRef(WasmSectionTypes));
 171     W.printNumber("Size", static_cast<uint64_t>(WasmSec.Content.size()));
 172     W.printNumber("Offset", WasmSec.Offset);
 173     switch (WasmSec.Type) {
 174     case wasm::WASM_SEC_CUSTOM:
 175       W.printString("Name", WasmSec.Name);
 176       if (WasmSec.Name == "linking") {
 177         const wasm::WasmLinkingData &LinkingData = Obj->linkingData();
 178         if (!LinkingData.InitFunctions.empty()) {
 179           ListScope Group(W, "InitFunctions");
 180           for (const wasm::WasmInitFunc &F : LinkingData.InitFunctions)
 181             W.startLine() << F.Symbol << " (priority=" << F.Priority << ")\n";
 182         }
 183       }
 184       break;
 185     case wasm::WASM_SEC_DATA: {
 186       ListScope Group(W, "Segments");
 187       for (const WasmSegment &Segment : Obj->dataSegments()) {
 188         const wasm::WasmDataSegment &Seg = Segment.Data;
 189         DictScope Group(W, "Segment");
 190         if (!Seg.Name.empty())
 191           W.printString("Name", Seg.Name);
 192         W.printNumber("Size", static_cast<uint64_t>(Seg.Content.size()));
 193         if (Seg.Offset.Opcode == wasm::WASM_OPCODE_I32_CONST)
 194           W.printNumber("Offset", Seg.Offset.Value.Int32);
 195       }
 196       break;
 197     }
 198     case wasm::WASM_SEC_MEMORY:
 199       ListScope Group(W, "Memories");
 200       for (const wasm::WasmLimits &Memory : Obj->memories()) {
 201         DictScope Group(W, "Memory");
 202         W.printNumber("InitialPages", Memory.Initial);
 203         if (Memory.Flags & wasm::WASM_LIMITS_FLAG_HAS_MAX) {
 204           W.printNumber("MaxPages", WasmSec.Offset);
 205         }
 206       }
 207       break;
 208     }
 209
 210     if (opts::SectionRelocations) {
 211       ListScope D(W, "Relocations");
 212       for (const RelocationRef &Reloc : Section.relocations())
 213         printRelocation(Section, Reloc);
 214     }
 215
 216     if (opts::SectionData) {
 217       W.printBinaryBlock("SectionData", WasmSec.Content);
 218     }
 219   }
 220 }
 221
 222 void WasmDumper::printSymbol(const SymbolRef &Sym) {
 223   DictScope D(W, "Symbol");
 224   WasmSymbol Symbol = Obj->getWasmSymbol(Sym.getRawDataRefImpl());
 225   W.printString("Name", Symbol.Info.Name);
 226   W.printEnum("Type", Symbol.Info.Kind, makeArrayRef(WasmSymbolTypes));
 227   W.printFlags("Flags", Symbol.Info.Flags, makeArrayRef(WasmSymbolFlags));
 228
 229   if (Symbol.Info.Flags & wasm::WASM_SYMBOL_UNDEFINED) {
 230     W.printString("ImportName", Symbol.Info.ImportName);
 231     W.printString("ImportModule", Symbol.Info.ImportModule);
 232   }
 233   if (Symbol.Info.Kind != wasm::WASM_SYMBOL_TYPE_DATA) {
 234     W.printHex("ElementIndex", Symbol.Info.ElementIndex);
 235   } else if (!(Symbol.Info.Flags & wasm::WASM_SYMBOL_UNDEFINED)) {
 236     W.printHex("Offset", Symbol.Info.DataRef.Offset);
 237     W.printHex("Segment", Symbol.Info.DataRef.Segment);
 238     W.printHex("Size", Symbol.Info.DataRef.Size);
 239   }
 240 }
 241
 242 } // namespace
 243
 244 namespace llvm {
 245
 246 std::error_code createWasmDumper(const object::ObjectFile *Obj,
 247                                  ScopedPrinter &Writer,
 248                                  std::unique_ptr<ObjDumper> &Result) {
 249   const auto *WasmObj = dyn_cast<WasmObjectFile>(Obj);
 250   assert(WasmObj && "createWasmDumper called with non-wasm object");
 251
 252   Result.reset(new WasmDumper(WasmObj, Writer));
 253   return readobj_error::success;
 254 }
 255
 256 } // namespace llvm