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 "ObjDumper.h"
14 #include "llvm-readobj.h"
15 #include "llvm/Object/Wasm.h"
16 #include "llvm/Support/ScopedPrinter.h"
17 
18 using namespace llvm;
19 using namespace object;
20 
21 namespace {
22 
23 const EnumEntry<unsigned> WasmSymbolTypes[] = {
24 #define ENUM_ENTRY(X)                                                          \
25   { #X, wasm::WASM_SYMBOL_TYPE_##X }
26     ENUM_ENTRY(FUNCTION), ENUM_ENTRY(DATA), ENUM_ENTRY(GLOBAL),
27     ENUM_ENTRY(SECTION),  ENUM_ENTRY(TAG),  ENUM_ENTRY(TABLE),
28 #undef ENUM_ENTRY
29 };
30 
31 const EnumEntry<uint32_t> WasmSectionTypes[] = {
32 #define ENUM_ENTRY(X)                                                          \
33   { #X, wasm::WASM_SEC_##X }
34     ENUM_ENTRY(CUSTOM),   ENUM_ENTRY(TYPE),      ENUM_ENTRY(IMPORT),
35     ENUM_ENTRY(FUNCTION), ENUM_ENTRY(TABLE),     ENUM_ENTRY(MEMORY),
36     ENUM_ENTRY(GLOBAL),   ENUM_ENTRY(TAG),       ENUM_ENTRY(EXPORT),
37     ENUM_ENTRY(START),    ENUM_ENTRY(ELEM),      ENUM_ENTRY(CODE),
38     ENUM_ENTRY(DATA),     ENUM_ENTRY(DATACOUNT),
39 #undef ENUM_ENTRY
40 };
41 
42 const EnumEntry<unsigned> WasmSymbolFlags[] = {
43 #define ENUM_ENTRY(X)                                                          \
44   { #X, wasm::WASM_SYMBOL_##X }
45   ENUM_ENTRY(BINDING_GLOBAL),
46   ENUM_ENTRY(BINDING_WEAK),
47   ENUM_ENTRY(BINDING_LOCAL),
48   ENUM_ENTRY(VISIBILITY_DEFAULT),
49   ENUM_ENTRY(VISIBILITY_HIDDEN),
50   ENUM_ENTRY(UNDEFINED),
51   ENUM_ENTRY(EXPORTED),
52   ENUM_ENTRY(EXPLICIT_NAME),
53   ENUM_ENTRY(NO_STRIP),
54 #undef ENUM_ENTRY
55 };
56 
57 class WasmDumper : public ObjDumper {
58 public:
59   WasmDumper(const WasmObjectFile *Obj, ScopedPrinter &Writer)
60       : ObjDumper(Writer, Obj->getFileName()), 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 = wasm::relocTypeHasAddend(static_cast<uint32_t>(RelocType));
96 
97   if (opts::ExpandRelocs) {
98     DictScope Group(W, "Relocation");
99     W.printNumber("Type", RelocTypeName, RelocType);
100     W.printHex("Offset", Reloc.getOffset());
101     if (!SymName.empty())
102       W.printString("Symbol", SymName);
103     else
104       W.printHex("Index", WasmReloc.Index);
105     if (HasAddend)
106       W.printNumber("Addend", WasmReloc.Addend);
107   } else {
108     raw_ostream &OS = W.startLine();
109     OS << W.hex(Reloc.getOffset()) << " " << RelocTypeName << " ";
110     if (!SymName.empty())
111       OS << SymName;
112     else
113       OS << WasmReloc.Index;
114     if (HasAddend)
115       OS << " " << WasmReloc.Addend;
116     OS << "\n";
117   }
118 }
119 
120 void WasmDumper::printRelocations() {
121   ListScope D(W, "Relocations");
122 
123   int SectionNumber = 0;
124   for (const SectionRef &Section : Obj->sections()) {
125     bool PrintedGroup = false;
126     StringRef Name = unwrapOrError(Obj->getFileName(), Section.getName());
127 
128     ++SectionNumber;
129 
130     for (const RelocationRef &Reloc : Section.relocations()) {
131       if (!PrintedGroup) {
132         W.startLine() << "Section (" << SectionNumber << ") " << Name << " {\n";
133         W.indent();
134         PrintedGroup = true;
135       }
136 
137       printRelocation(Section, Reloc);
138     }
139 
140     if (PrintedGroup) {
141       W.unindent();
142       W.startLine() << "}\n";
143     }
144   }
145 }
146 
147 void WasmDumper::printSymbols() {
148   ListScope Group(W, "Symbols");
149 
150   for (const SymbolRef &Symbol : Obj->symbols())
151     printSymbol(Symbol);
152 }
153 
154 void WasmDumper::printSectionHeaders() {
155   ListScope Group(W, "Sections");
156   for (const SectionRef &Section : Obj->sections()) {
157     const WasmSection &WasmSec = Obj->getWasmSection(Section);
158     DictScope SectionD(W, "Section");
159     W.printEnum("Type", WasmSec.Type, ArrayRef(WasmSectionTypes));
160     W.printNumber("Size", static_cast<uint64_t>(WasmSec.Content.size()));
161     W.printNumber("Offset", WasmSec.Offset);
162     switch (WasmSec.Type) {
163     case wasm::WASM_SEC_CUSTOM:
164       W.printString("Name", WasmSec.Name);
165       if (WasmSec.Name == "linking") {
166         const wasm::WasmLinkingData &LinkingData = Obj->linkingData();
167         if (!LinkingData.InitFunctions.empty()) {
168           ListScope Group(W, "InitFunctions");
169           for (const wasm::WasmInitFunc &F : LinkingData.InitFunctions)
170             W.startLine() << F.Symbol << " (priority=" << F.Priority << ")\n";
171         }
172       }
173       break;
174     case wasm::WASM_SEC_DATA: {
175       ListScope Group(W, "Segments");
176       for (const WasmSegment &Segment : Obj->dataSegments()) {
177         const wasm::WasmDataSegment &Seg = Segment.Data;
178         DictScope Group(W, "Segment");
179         if (!Seg.Name.empty())
180           W.printString("Name", Seg.Name);
181         W.printNumber("Size", static_cast<uint64_t>(Seg.Content.size()));
182         if (Seg.Offset.Extended)
183           llvm_unreachable("extended const exprs not supported");
184         else if (Seg.Offset.Inst.Opcode == wasm::WASM_OPCODE_I32_CONST)
185           W.printNumber("Offset", Seg.Offset.Inst.Value.Int32);
186         else if (Seg.Offset.Inst.Opcode == wasm::WASM_OPCODE_I64_CONST)
187           W.printNumber("Offset", Seg.Offset.Inst.Value.Int64);
188         else if (Seg.Offset.Inst.Opcode == wasm::WASM_OPCODE_GLOBAL_GET) {
189           ListScope Group(W, "Offset");
190           W.printNumber("Global", Seg.Offset.Inst.Value.Global);
191         } else
192           llvm_unreachable("unknown init expr opcode");
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("MinPages", Memory.Minimum);
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, ArrayRef(WasmSymbolTypes));
225   W.printFlags("Flags", Symbol.Info.Flags, ArrayRef(WasmSymbolFlags));
226 
227   if (Symbol.Info.Flags & wasm::WASM_SYMBOL_UNDEFINED) {
228     if (Symbol.Info.ImportName) {
229       W.printString("ImportName", *Symbol.Info.ImportName);
230     }
231     if (Symbol.Info.ImportModule) {
232       W.printString("ImportModule", *Symbol.Info.ImportModule);
233     }
234   }
235   if (Symbol.Info.Kind != wasm::WASM_SYMBOL_TYPE_DATA) {
236     W.printHex("ElementIndex", Symbol.Info.ElementIndex);
237   } else if (!(Symbol.Info.Flags & wasm::WASM_SYMBOL_UNDEFINED)) {
238     W.printHex("Offset", Symbol.Info.DataRef.Offset);
239     W.printHex("Segment", Symbol.Info.DataRef.Segment);
240     W.printHex("Size", Symbol.Info.DataRef.Size);
241   }
242 }
243 
244 } // namespace
245 
246 namespace llvm {
247 
248 std::unique_ptr<ObjDumper> createWasmDumper(const object::WasmObjectFile &Obj,
249                                             ScopedPrinter &Writer) {
250   return std::make_unique<WasmDumper>(&Obj, Writer);
251 }
252 
253 } // namespace llvm
254