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
257