WasmDumper.cpp revision 360784 
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
19using namespace llvm;
20using namespace object;
21
22namespace {
23
24static 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
32static 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
43static 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
58class WasmDumper : public ObjDumper {
59public:
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
69protected:
70  void printSymbol(const SymbolRef &Sym);
71  void printRelocation(const SectionRef &Section, const RelocationRef &Reloc);
72
73private:
74  void printSymbols() override;
75  void printDynamicSymbols() override { llvm_unreachable("unimplemented"); }
76
77  const WasmObjectFile *Obj;
78};
79
80void WasmDumper::printFileHeaders() {
81  W.printHex("Version", Obj->getHeader().Version);
82}
83
84void 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
131void 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
158void WasmDumper::printSymbols() {
159  ListScope Group(W, "Symbols");
160
161  for (const SymbolRef &Symbol : Obj->symbols())
162    printSymbol(Symbol);
163}
164
165void 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
222void 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
244namespace llvm {
245
246std::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
257