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),
  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 #undef ENUM_ENTRY
  54 };
  55
  56 class WasmDumper : public ObjDumper {
  57 public:
  58   WasmDumper(const WasmObjectFile *Obj, ScopedPrinter &Writer)
  59       : ObjDumper(Writer), Obj(Obj) {}
  60
  61   void printFileHeaders() override;
  62   void printSectionHeaders() override;
  63   void printRelocations() override;
  64   void printUnwindInfo() override { llvm_unreachable("unimplemented"); }
  65   void printStackMap() const override { llvm_unreachable("unimplemented"); }
  66
  67 protected:
  68   void printSymbol(const SymbolRef &Sym);
  69   void printRelocation(const SectionRef &Section, const RelocationRef &Reloc);
  70
  71 private:
  72   void printSymbols() override;
  73   void printDynamicSymbols() override { llvm_unreachable("unimplemented"); }
  74
  75   const WasmObjectFile *Obj;
  76 };
  77
  78 void WasmDumper::printFileHeaders() {
  79   W.printHex("Version", Obj->getHeader().Version);
  80 }
  81
  82 void WasmDumper::printRelocation(const SectionRef &Section,
  83                                  const RelocationRef &Reloc) {
  84   SmallString<64> RelocTypeName;
  85   uint64_t RelocType = Reloc.getType();
  86   Reloc.getTypeName(RelocTypeName);
  87   const wasm::WasmRelocation &WasmReloc = Obj->getWasmRelocation(Reloc);
  88
  89   StringRef SymName;
  90   symbol_iterator SI = Reloc.getSymbol();
  91   if (SI != Obj->symbol_end())
  92     SymName = error(SI->getName());
  93
  94   bool HasAddend = false;
  95   switch (RelocType) {
  96   case wasm::R_WASM_MEMORY_ADDR_LEB:
  97   case wasm::R_WASM_MEMORY_ADDR_SLEB:
  98   case wasm::R_WASM_MEMORY_ADDR_I32:
  99   case wasm::R_WASM_FUNCTION_OFFSET_I32:
 100   case wasm::R_WASM_SECTION_OFFSET_I32:
 101     HasAddend = true;
 102     break;
 103   default:
 104     break;
 105   }
 106   if (opts::ExpandRelocs) {
 107     DictScope Group(W, "Relocation");
 108     W.printNumber("Type", RelocTypeName, RelocType);
 109     W.printHex("Offset", Reloc.getOffset());
 110     if (!SymName.empty())
 111       W.printString("Symbol", SymName);
 112     else
 113       W.printHex("Index", WasmReloc.Index);
 114     if (HasAddend)
 115       W.printNumber("Addend", WasmReloc.Addend);
 116   } else {
 117     raw_ostream &OS = W.startLine();
 118     OS << W.hex(Reloc.getOffset()) << " " << RelocTypeName << " ";
 119     if (!SymName.empty())
 120       OS << SymName;
 121     else
 122       OS << WasmReloc.Index;
 123     if (HasAddend)
 124       OS << " " << WasmReloc.Addend;
 125     OS << "\n";
 126   }
 127 }
 128
 129 void WasmDumper::printRelocations() {
 130   ListScope D(W, "Relocations");
 131
 132   int SectionNumber = 0;
 133   for (const SectionRef &Section : Obj->sections()) {
 134     bool PrintedGroup = false;
 135     StringRef Name;
 136     error(Section.getName(Name));
 137     ++SectionNumber;
 138
 139     for (const RelocationRef &Reloc : Section.relocations()) {
 140       if (!PrintedGroup) {
 141         W.startLine() << "Section (" << SectionNumber << ") " << Name << " {\n";
 142         W.indent();
 143         PrintedGroup = true;
 144       }
 145
 146       printRelocation(Section, Reloc);
 147     }
 148
 149     if (PrintedGroup) {
 150       W.unindent();
 151       W.startLine() << "}\n";
 152     }
 153   }
 154 }
 155
 156 void WasmDumper::printSymbols() {
 157   ListScope Group(W, "Symbols");
 158
 159   for (const SymbolRef &Symbol : Obj->symbols())
 160     printSymbol(Symbol);
 161 }
 162
 163 void WasmDumper::printSectionHeaders() {
 164   ListScope Group(W, "Sections");
 165   for (const SectionRef &Section : Obj->sections()) {
 166     const WasmSection &WasmSec = Obj->getWasmSection(Section);
 167     DictScope SectionD(W, "Section");
 168     W.printEnum("Type", WasmSec.Type, makeArrayRef(WasmSectionTypes));
 169     W.printNumber("Size", static_cast<uint64_t>(WasmSec.Content.size()));
 170     W.printNumber("Offset", WasmSec.Offset);
 171     switch (WasmSec.Type) {
 172     case wasm::WASM_SEC_CUSTOM:
 173       W.printString("Name", WasmSec.Name);
 174       if (WasmSec.Name == "linking") {
 175         const wasm::WasmLinkingData &LinkingData = Obj->linkingData();
 176         if (!LinkingData.InitFunctions.empty()) {
 177           ListScope Group(W, "InitFunctions");
 178           for (const wasm::WasmInitFunc &F : LinkingData.InitFunctions)
 179             W.startLine() << F.Symbol << " (priority=" << F.Priority << ")\n";
 180         }
 181       }
 182       break;
 183     case wasm::WASM_SEC_DATA: {
 184       ListScope Group(W, "Segments");
 185       for (const WasmSegment &Segment : Obj->dataSegments()) {
 186         const wasm::WasmDataSegment &Seg = Segment.Data;
 187         DictScope Group(W, "Segment");
 188         if (!Seg.Name.empty())
 189           W.printString("Name", Seg.Name);
 190         W.printNumber("Size", static_cast<uint64_t>(Seg.Content.size()));
 191         if (Seg.Offset.Opcode == wasm::WASM_OPCODE_I32_CONST)
 192           W.printNumber("Offset", Seg.Offset.Value.Int32);
 193       }
 194       break;
 195     }
 196     case wasm::WASM_SEC_MEMORY:
 197       ListScope Group(W, "Memories");
 198       for (const wasm::WasmLimits &Memory : Obj->memories()) {
 199         DictScope Group(W, "Memory");
 200         W.printNumber("InitialPages", Memory.Initial);
 201         if (Memory.Flags & wasm::WASM_LIMITS_FLAG_HAS_MAX) {
 202           W.printNumber("MaxPages", WasmSec.Offset);
 203         }
 204       }
 205       break;
 206     }
 207
 208     if (opts::SectionRelocations) {
 209       ListScope D(W, "Relocations");
 210       for (const RelocationRef &Reloc : Section.relocations())
 211         printRelocation(Section, Reloc);
 212     }
 213
 214     if (opts::SectionData) {
 215       W.printBinaryBlock("SectionData", WasmSec.Content);
 216     }
 217   }
 218 }
 219
 220 void WasmDumper::printSymbol(const SymbolRef &Sym) {
 221   DictScope D(W, "Symbol");
 222   WasmSymbol Symbol = Obj->getWasmSymbol(Sym.getRawDataRefImpl());
 223   W.printString("Name", Symbol.Info.Name);
 224   W.printEnum("Type", Symbol.Info.Kind, makeArrayRef(WasmSymbolTypes));
 225   W.printFlags("Flags", Symbol.Info.Flags, makeArrayRef(WasmSymbolFlags));
 226
 227   if (Symbol.Info.Flags & wasm::WASM_SYMBOL_UNDEFINED) {
 228     W.printString("ImportName", Symbol.Info.ImportName);
 229     W.printString("ImportModule", Symbol.Info.ImportModule);
 230   }
 231   if (Symbol.Info.Kind != wasm::WASM_SYMBOL_TYPE_DATA) {
 232     W.printHex("ElementIndex", Symbol.Info.ElementIndex);
 233   } else if (!(Symbol.Info.Flags & wasm::WASM_SYMBOL_UNDEFINED)) {
 234     W.printHex("Offset", Symbol.Info.DataRef.Offset);
 235     W.printHex("Segment", Symbol.Info.DataRef.Segment);
 236     W.printHex("Size", Symbol.Info.DataRef.Size);
 237   }
 238 }
 239
 240 } // namespace
 241
 242 namespace llvm {
 243
 244 std::error_code createWasmDumper(const object::ObjectFile *Obj,
 245                                  ScopedPrinter &Writer,
 246                                  std::unique_ptr<ObjDumper> &Result) {
 247   const auto *WasmObj = dyn_cast<WasmObjectFile>(Obj);
 248   assert(WasmObj && "createWasmDumper called with non-wasm object");
 249
 250   Result.reset(new WasmDumper(WasmObj, Writer));
 251   return readobj_error::success;
 252 }
 253
 254 } // namespace llvm