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