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1 //===- WasmObjectFile.cpp - Wasm object file implementation ---------------===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 
10 #include "llvm/ADT/ArrayRef.h"
11 #include "llvm/ADT/DenseSet.h"
12 #include "llvm/ADT/STLExtras.h"
13 #include "llvm/ADT/StringRef.h"
14 #include "llvm/ADT/StringSet.h"
15 #include "llvm/ADT/Triple.h"
16 #include "llvm/BinaryFormat/Wasm.h"
17 #include "llvm/MC/SubtargetFeature.h"
18 #include "llvm/Object/Binary.h"
19 #include "llvm/Object/Error.h"
20 #include "llvm/Object/ObjectFile.h"
21 #include "llvm/Object/SymbolicFile.h"
22 #include "llvm/Object/Wasm.h"
23 #include "llvm/Support/Endian.h"
24 #include "llvm/Support/Error.h"
25 #include "llvm/Support/ErrorHandling.h"
26 #include "llvm/Support/LEB128.h"
27 #include <algorithm>
28 #include <cassert>
29 #include <cstdint>
30 #include <cstring>
31 #include <system_error>
32 
33 #define DEBUG_TYPE "wasm-object"
34 
35 using namespace llvm;
36 using namespace object;
37 
print(raw_ostream & Out) const38 void WasmSymbol::print(raw_ostream &Out) const {
39   Out << "Name=" << Info.Name
40   << ", Kind=" << toString(wasm::WasmSymbolType(Info.Kind))
41   << ", Flags=" << Info.Flags;
42   if (!isTypeData()) {
43     Out << ", ElemIndex=" << Info.ElementIndex;
44   } else if (isDefined()) {
45     Out << ", Segment=" << Info.DataRef.Segment;
46     Out << ", Offset=" << Info.DataRef.Offset;
47     Out << ", Size=" << Info.DataRef.Size;
48   }
49 }
50 
51 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
dump() const52 LLVM_DUMP_METHOD void WasmSymbol::dump() const { print(dbgs()); }
53 #endif
54 
55 Expected<std::unique_ptr<WasmObjectFile>>
createWasmObjectFile(MemoryBufferRef Buffer)56 ObjectFile::createWasmObjectFile(MemoryBufferRef Buffer) {
57   Error Err = Error::success();
58   auto ObjectFile = llvm::make_unique<WasmObjectFile>(Buffer, Err);
59   if (Err)
60     return std::move(Err);
61 
62   return std::move(ObjectFile);
63 }
64 
65 #define VARINT7_MAX ((1<<7)-1)
66 #define VARINT7_MIN (-(1<<7))
67 #define VARUINT7_MAX (1<<7)
68 #define VARUINT1_MAX (1)
69 
readUint8(WasmObjectFile::ReadContext & Ctx)70 static uint8_t readUint8(WasmObjectFile::ReadContext &Ctx) {
71   if (Ctx.Ptr == Ctx.End)
72     report_fatal_error("EOF while reading uint8");
73   return *Ctx.Ptr++;
74 }
75 
readUint32(WasmObjectFile::ReadContext & Ctx)76 static uint32_t readUint32(WasmObjectFile::ReadContext &Ctx) {
77   if (Ctx.Ptr + 4 > Ctx.End)
78     report_fatal_error("EOF while reading uint32");
79   uint32_t Result = support::endian::read32le(Ctx.Ptr);
80   Ctx.Ptr += 4;
81   return Result;
82 }
83 
readFloat32(WasmObjectFile::ReadContext & Ctx)84 static int32_t readFloat32(WasmObjectFile::ReadContext &Ctx) {
85   int32_t Result = 0;
86   memcpy(&Result, Ctx.Ptr, sizeof(Result));
87   Ctx.Ptr += sizeof(Result);
88   return Result;
89 }
90 
readFloat64(WasmObjectFile::ReadContext & Ctx)91 static int64_t readFloat64(WasmObjectFile::ReadContext &Ctx) {
92   int64_t Result = 0;
93   memcpy(&Result, Ctx.Ptr, sizeof(Result));
94   Ctx.Ptr += sizeof(Result);
95   return Result;
96 }
97 
readULEB128(WasmObjectFile::ReadContext & Ctx)98 static uint64_t readULEB128(WasmObjectFile::ReadContext &Ctx) {
99   unsigned Count;
100   const char* Error = nullptr;
101   uint64_t Result = decodeULEB128(Ctx.Ptr, &Count, Ctx.End, &Error);
102   if (Error)
103     report_fatal_error(Error);
104   Ctx.Ptr += Count;
105   return Result;
106 }
107 
readString(WasmObjectFile::ReadContext & Ctx)108 static StringRef readString(WasmObjectFile::ReadContext &Ctx) {
109   uint32_t StringLen = readULEB128(Ctx);
110   if (Ctx.Ptr + StringLen > Ctx.End)
111     report_fatal_error("EOF while reading string");
112   StringRef Return =
113       StringRef(reinterpret_cast<const char *>(Ctx.Ptr), StringLen);
114   Ctx.Ptr += StringLen;
115   return Return;
116 }
117 
readLEB128(WasmObjectFile::ReadContext & Ctx)118 static int64_t readLEB128(WasmObjectFile::ReadContext &Ctx) {
119   unsigned Count;
120   const char* Error = nullptr;
121   uint64_t Result = decodeSLEB128(Ctx.Ptr, &Count, Ctx.End, &Error);
122   if (Error)
123     report_fatal_error(Error);
124   Ctx.Ptr += Count;
125   return Result;
126 }
127 
readVaruint1(WasmObjectFile::ReadContext & Ctx)128 static uint8_t readVaruint1(WasmObjectFile::ReadContext &Ctx) {
129   int64_t result = readLEB128(Ctx);
130   if (result > VARUINT1_MAX || result < 0)
131     report_fatal_error("LEB is outside Varuint1 range");
132   return result;
133 }
134 
readVarint32(WasmObjectFile::ReadContext & Ctx)135 static int32_t readVarint32(WasmObjectFile::ReadContext &Ctx) {
136   int64_t result = readLEB128(Ctx);
137   if (result > INT32_MAX || result < INT32_MIN)
138     report_fatal_error("LEB is outside Varint32 range");
139   return result;
140 }
141 
readVaruint32(WasmObjectFile::ReadContext & Ctx)142 static uint32_t readVaruint32(WasmObjectFile::ReadContext &Ctx) {
143   uint64_t result = readULEB128(Ctx);
144   if (result > UINT32_MAX)
145     report_fatal_error("LEB is outside Varuint32 range");
146   return result;
147 }
148 
readVarint64(WasmObjectFile::ReadContext & Ctx)149 static int64_t readVarint64(WasmObjectFile::ReadContext &Ctx) {
150   return readLEB128(Ctx);
151 }
152 
readOpcode(WasmObjectFile::ReadContext & Ctx)153 static uint8_t readOpcode(WasmObjectFile::ReadContext &Ctx) {
154   return readUint8(Ctx);
155 }
156 
readInitExpr(wasm::WasmInitExpr & Expr,WasmObjectFile::ReadContext & Ctx)157 static Error readInitExpr(wasm::WasmInitExpr &Expr,
158                           WasmObjectFile::ReadContext &Ctx) {
159   Expr.Opcode = readOpcode(Ctx);
160 
161   switch (Expr.Opcode) {
162   case wasm::WASM_OPCODE_I32_CONST:
163     Expr.Value.Int32 = readVarint32(Ctx);
164     break;
165   case wasm::WASM_OPCODE_I64_CONST:
166     Expr.Value.Int64 = readVarint64(Ctx);
167     break;
168   case wasm::WASM_OPCODE_F32_CONST:
169     Expr.Value.Float32 = readFloat32(Ctx);
170     break;
171   case wasm::WASM_OPCODE_F64_CONST:
172     Expr.Value.Float64 = readFloat64(Ctx);
173     break;
174   case wasm::WASM_OPCODE_GET_GLOBAL:
175     Expr.Value.Global = readULEB128(Ctx);
176     break;
177   default:
178     return make_error<GenericBinaryError>("Invalid opcode in init_expr",
179                                           object_error::parse_failed);
180   }
181 
182   uint8_t EndOpcode = readOpcode(Ctx);
183   if (EndOpcode != wasm::WASM_OPCODE_END) {
184     return make_error<GenericBinaryError>("Invalid init_expr",
185                                           object_error::parse_failed);
186   }
187   return Error::success();
188 }
189 
readLimits(WasmObjectFile::ReadContext & Ctx)190 static wasm::WasmLimits readLimits(WasmObjectFile::ReadContext &Ctx) {
191   wasm::WasmLimits Result;
192   Result.Flags = readVaruint1(Ctx);
193   Result.Initial = readVaruint32(Ctx);
194   if (Result.Flags & wasm::WASM_LIMITS_FLAG_HAS_MAX)
195     Result.Maximum = readVaruint32(Ctx);
196   return Result;
197 }
198 
readTable(WasmObjectFile::ReadContext & Ctx)199 static wasm::WasmTable readTable(WasmObjectFile::ReadContext &Ctx) {
200   wasm::WasmTable Table;
201   Table.ElemType = readUint8(Ctx);
202   Table.Limits = readLimits(Ctx);
203   return Table;
204 }
205 
readSection(WasmSection & Section,WasmObjectFile::ReadContext & Ctx)206 static Error readSection(WasmSection &Section,
207                          WasmObjectFile::ReadContext &Ctx) {
208   Section.Offset = Ctx.Ptr - Ctx.Start;
209   Section.Type = readUint8(Ctx);
210   LLVM_DEBUG(dbgs() << "readSection type=" << Section.Type << "\n");
211   uint32_t Size = readVaruint32(Ctx);
212   if (Size == 0)
213     return make_error<StringError>("Zero length section",
214                                    object_error::parse_failed);
215   if (Ctx.Ptr + Size > Ctx.End)
216     return make_error<StringError>("Section too large",
217                                    object_error::parse_failed);
218   if (Section.Type == wasm::WASM_SEC_CUSTOM) {
219     const uint8_t *NameStart = Ctx.Ptr;
220     Section.Name = readString(Ctx);
221     Size -= Ctx.Ptr - NameStart;
222   }
223   Section.Content = ArrayRef<uint8_t>(Ctx.Ptr, Size);
224   Ctx.Ptr += Size;
225   return Error::success();
226 }
227 
WasmObjectFile(MemoryBufferRef Buffer,Error & Err)228 WasmObjectFile::WasmObjectFile(MemoryBufferRef Buffer, Error &Err)
229     : ObjectFile(Binary::ID_Wasm, Buffer) {
230   ErrorAsOutParameter ErrAsOutParam(&Err);
231   Header.Magic = getData().substr(0, 4);
232   if (Header.Magic != StringRef("\0asm", 4)) {
233     Err = make_error<StringError>("Bad magic number",
234                                   object_error::parse_failed);
235     return;
236   }
237 
238   ReadContext Ctx;
239   Ctx.Start = getPtr(0);
240   Ctx.Ptr = Ctx.Start + 4;
241   Ctx.End = Ctx.Start + getData().size();
242 
243   if (Ctx.Ptr + 4 > Ctx.End) {
244     Err = make_error<StringError>("Missing version number",
245                                   object_error::parse_failed);
246     return;
247   }
248 
249   Header.Version = readUint32(Ctx);
250   if (Header.Version != wasm::WasmVersion) {
251     Err = make_error<StringError>("Bad version number",
252                                   object_error::parse_failed);
253     return;
254   }
255 
256   WasmSection Sec;
257   while (Ctx.Ptr < Ctx.End) {
258     if ((Err = readSection(Sec, Ctx)))
259       return;
260     if ((Err = parseSection(Sec)))
261       return;
262 
263     Sections.push_back(Sec);
264   }
265 }
266 
parseSection(WasmSection & Sec)267 Error WasmObjectFile::parseSection(WasmSection &Sec) {
268   ReadContext Ctx;
269   Ctx.Start = Sec.Content.data();
270   Ctx.End = Ctx.Start + Sec.Content.size();
271   Ctx.Ptr = Ctx.Start;
272   switch (Sec.Type) {
273   case wasm::WASM_SEC_CUSTOM:
274     return parseCustomSection(Sec, Ctx);
275   case wasm::WASM_SEC_TYPE:
276     return parseTypeSection(Ctx);
277   case wasm::WASM_SEC_IMPORT:
278     return parseImportSection(Ctx);
279   case wasm::WASM_SEC_FUNCTION:
280     return parseFunctionSection(Ctx);
281   case wasm::WASM_SEC_TABLE:
282     return parseTableSection(Ctx);
283   case wasm::WASM_SEC_MEMORY:
284     return parseMemorySection(Ctx);
285   case wasm::WASM_SEC_GLOBAL:
286     return parseGlobalSection(Ctx);
287   case wasm::WASM_SEC_EXPORT:
288     return parseExportSection(Ctx);
289   case wasm::WASM_SEC_START:
290     return parseStartSection(Ctx);
291   case wasm::WASM_SEC_ELEM:
292     return parseElemSection(Ctx);
293   case wasm::WASM_SEC_CODE:
294     return parseCodeSection(Ctx);
295   case wasm::WASM_SEC_DATA:
296     return parseDataSection(Ctx);
297   default:
298     return make_error<GenericBinaryError>("Bad section type",
299                                           object_error::parse_failed);
300   }
301 }
302 
parseNameSection(ReadContext & Ctx)303 Error WasmObjectFile::parseNameSection(ReadContext &Ctx) {
304   llvm::DenseSet<uint64_t> Seen;
305   if (Functions.size() != FunctionTypes.size()) {
306     return make_error<GenericBinaryError>("Names must come after code section",
307                                           object_error::parse_failed);
308   }
309 
310   while (Ctx.Ptr < Ctx.End) {
311     uint8_t Type = readUint8(Ctx);
312     uint32_t Size = readVaruint32(Ctx);
313     const uint8_t *SubSectionEnd = Ctx.Ptr + Size;
314     switch (Type) {
315     case wasm::WASM_NAMES_FUNCTION: {
316       uint32_t Count = readVaruint32(Ctx);
317       while (Count--) {
318         uint32_t Index = readVaruint32(Ctx);
319         if (!Seen.insert(Index).second)
320           return make_error<GenericBinaryError>("Function named more than once",
321                                                 object_error::parse_failed);
322         StringRef Name = readString(Ctx);
323         if (!isValidFunctionIndex(Index) || Name.empty())
324           return make_error<GenericBinaryError>("Invalid name entry",
325                                                 object_error::parse_failed);
326         DebugNames.push_back(wasm::WasmFunctionName{Index, Name});
327         if (isDefinedFunctionIndex(Index))
328           getDefinedFunction(Index).DebugName = Name;
329       }
330       break;
331     }
332     // Ignore local names for now
333     case wasm::WASM_NAMES_LOCAL:
334     default:
335       Ctx.Ptr += Size;
336       break;
337     }
338     if (Ctx.Ptr != SubSectionEnd)
339       return make_error<GenericBinaryError>("Name sub-section ended prematurely",
340                                             object_error::parse_failed);
341   }
342 
343   if (Ctx.Ptr != Ctx.End)
344     return make_error<GenericBinaryError>("Name section ended prematurely",
345                                           object_error::parse_failed);
346   return Error::success();
347 }
348 
parseLinkingSection(ReadContext & Ctx)349 Error WasmObjectFile::parseLinkingSection(ReadContext &Ctx) {
350   HasLinkingSection = true;
351   if (Functions.size() != FunctionTypes.size()) {
352     return make_error<GenericBinaryError>(
353         "Linking data must come after code section", object_error::parse_failed);
354   }
355 
356   LinkingData.Version = readVaruint32(Ctx);
357   if (LinkingData.Version != wasm::WasmMetadataVersion) {
358     return make_error<GenericBinaryError>(
359         "Unexpected metadata version: " + Twine(LinkingData.Version) +
360             " (Expected: " + Twine(wasm::WasmMetadataVersion) + ")",
361         object_error::parse_failed);
362   }
363 
364   const uint8_t *OrigEnd = Ctx.End;
365   while (Ctx.Ptr < OrigEnd) {
366     Ctx.End = OrigEnd;
367     uint8_t Type = readUint8(Ctx);
368     uint32_t Size = readVaruint32(Ctx);
369     LLVM_DEBUG(dbgs() << "readSubsection type=" << int(Type) << " size=" << Size
370                       << "\n");
371     Ctx.End = Ctx.Ptr + Size;
372     switch (Type) {
373     case wasm::WASM_SYMBOL_TABLE:
374       if (Error Err = parseLinkingSectionSymtab(Ctx))
375         return Err;
376       break;
377     case wasm::WASM_SEGMENT_INFO: {
378       uint32_t Count = readVaruint32(Ctx);
379       if (Count > DataSegments.size())
380         return make_error<GenericBinaryError>("Too many segment names",
381                                               object_error::parse_failed);
382       for (uint32_t i = 0; i < Count; i++) {
383         DataSegments[i].Data.Name = readString(Ctx);
384         DataSegments[i].Data.Alignment = readVaruint32(Ctx);
385         DataSegments[i].Data.Flags = readVaruint32(Ctx);
386       }
387       break;
388     }
389     case wasm::WASM_INIT_FUNCS: {
390       uint32_t Count = readVaruint32(Ctx);
391       LinkingData.InitFunctions.reserve(Count);
392       for (uint32_t i = 0; i < Count; i++) {
393         wasm::WasmInitFunc Init;
394         Init.Priority = readVaruint32(Ctx);
395         Init.Symbol = readVaruint32(Ctx);
396         if (!isValidFunctionSymbol(Init.Symbol))
397           return make_error<GenericBinaryError>("Invalid function symbol: " +
398                                                     Twine(Init.Symbol),
399                                                 object_error::parse_failed);
400         LinkingData.InitFunctions.emplace_back(Init);
401       }
402       break;
403     }
404     case wasm::WASM_COMDAT_INFO:
405       if (Error Err = parseLinkingSectionComdat(Ctx))
406         return Err;
407       break;
408     default:
409       Ctx.Ptr += Size;
410       break;
411     }
412     if (Ctx.Ptr != Ctx.End)
413       return make_error<GenericBinaryError>(
414           "Linking sub-section ended prematurely", object_error::parse_failed);
415   }
416   if (Ctx.Ptr != OrigEnd)
417     return make_error<GenericBinaryError>("Linking section ended prematurely",
418                                           object_error::parse_failed);
419   return Error::success();
420 }
421 
parseLinkingSectionSymtab(ReadContext & Ctx)422 Error WasmObjectFile::parseLinkingSectionSymtab(ReadContext &Ctx) {
423   uint32_t Count = readVaruint32(Ctx);
424   LinkingData.SymbolTable.reserve(Count);
425   Symbols.reserve(Count);
426   StringSet<> SymbolNames;
427 
428   std::vector<wasm::WasmImport *> ImportedGlobals;
429   std::vector<wasm::WasmImport *> ImportedFunctions;
430   ImportedGlobals.reserve(Imports.size());
431   ImportedFunctions.reserve(Imports.size());
432   for (auto &I : Imports) {
433     if (I.Kind == wasm::WASM_EXTERNAL_FUNCTION)
434       ImportedFunctions.emplace_back(&I);
435     else if (I.Kind == wasm::WASM_EXTERNAL_GLOBAL)
436       ImportedGlobals.emplace_back(&I);
437   }
438 
439   while (Count--) {
440     wasm::WasmSymbolInfo Info;
441     const wasm::WasmSignature *FunctionType = nullptr;
442     const wasm::WasmGlobalType *GlobalType = nullptr;
443 
444     Info.Kind = readUint8(Ctx);
445     Info.Flags = readVaruint32(Ctx);
446     bool IsDefined = (Info.Flags & wasm::WASM_SYMBOL_UNDEFINED) == 0;
447 
448     switch (Info.Kind) {
449     case wasm::WASM_SYMBOL_TYPE_FUNCTION:
450       Info.ElementIndex = readVaruint32(Ctx);
451       if (!isValidFunctionIndex(Info.ElementIndex) ||
452           IsDefined != isDefinedFunctionIndex(Info.ElementIndex))
453         return make_error<GenericBinaryError>("invalid function symbol index",
454                                               object_error::parse_failed);
455       if (IsDefined) {
456         Info.Name = readString(Ctx);
457         unsigned FuncIndex = Info.ElementIndex - NumImportedFunctions;
458         FunctionType = &Signatures[FunctionTypes[FuncIndex]];
459         wasm::WasmFunction &Function = Functions[FuncIndex];
460         if (Function.SymbolName.empty())
461           Function.SymbolName = Info.Name;
462       } else {
463         wasm::WasmImport &Import = *ImportedFunctions[Info.ElementIndex];
464         FunctionType = &Signatures[Import.SigIndex];
465         Info.Name = Import.Field;
466         Info.Module = Import.Module;
467       }
468       break;
469 
470     case wasm::WASM_SYMBOL_TYPE_GLOBAL:
471       Info.ElementIndex = readVaruint32(Ctx);
472       if (!isValidGlobalIndex(Info.ElementIndex) ||
473           IsDefined != isDefinedGlobalIndex(Info.ElementIndex))
474         return make_error<GenericBinaryError>("invalid global symbol index",
475                                               object_error::parse_failed);
476       if (!IsDefined &&
477           (Info.Flags & wasm::WASM_SYMBOL_BINDING_MASK) ==
478               wasm::WASM_SYMBOL_BINDING_WEAK)
479         return make_error<GenericBinaryError>("undefined weak global symbol",
480                                               object_error::parse_failed);
481       if (IsDefined) {
482         Info.Name = readString(Ctx);
483         unsigned GlobalIndex = Info.ElementIndex - NumImportedGlobals;
484         wasm::WasmGlobal &Global = Globals[GlobalIndex];
485         GlobalType = &Global.Type;
486         if (Global.SymbolName.empty())
487           Global.SymbolName = Info.Name;
488       } else {
489         wasm::WasmImport &Import = *ImportedGlobals[Info.ElementIndex];
490         Info.Name = Import.Field;
491         GlobalType = &Import.Global;
492       }
493       break;
494 
495     case wasm::WASM_SYMBOL_TYPE_DATA:
496       Info.Name = readString(Ctx);
497       if (IsDefined) {
498         uint32_t Index = readVaruint32(Ctx);
499         if (Index >= DataSegments.size())
500           return make_error<GenericBinaryError>("invalid data symbol index",
501                                                 object_error::parse_failed);
502         uint32_t Offset = readVaruint32(Ctx);
503         uint32_t Size = readVaruint32(Ctx);
504         if (Offset + Size > DataSegments[Index].Data.Content.size())
505           return make_error<GenericBinaryError>("invalid data symbol offset",
506                                                 object_error::parse_failed);
507         Info.DataRef = wasm::WasmDataReference{Index, Offset, Size};
508       }
509       break;
510 
511     case wasm::WASM_SYMBOL_TYPE_SECTION: {
512       if ((Info.Flags & wasm::WASM_SYMBOL_BINDING_MASK) !=
513           wasm::WASM_SYMBOL_BINDING_LOCAL)
514         return make_error<GenericBinaryError>(
515             "Section symbols must have local binding",
516             object_error::parse_failed);
517       Info.ElementIndex = readVaruint32(Ctx);
518       // Use somewhat unique section name as symbol name.
519       StringRef SectionName = Sections[Info.ElementIndex].Name;
520       Info.Name = SectionName;
521       break;
522     }
523 
524     default:
525       return make_error<GenericBinaryError>("Invalid symbol type",
526                                             object_error::parse_failed);
527     }
528 
529     if ((Info.Flags & wasm::WASM_SYMBOL_BINDING_MASK) !=
530             wasm::WASM_SYMBOL_BINDING_LOCAL &&
531         !SymbolNames.insert(Info.Name).second)
532       return make_error<GenericBinaryError>("Duplicate symbol name " +
533                                                 Twine(Info.Name),
534                                             object_error::parse_failed);
535     LinkingData.SymbolTable.emplace_back(Info);
536     Symbols.emplace_back(LinkingData.SymbolTable.back(), FunctionType,
537                          GlobalType);
538     LLVM_DEBUG(dbgs() << "Adding symbol: " << Symbols.back() << "\n");
539   }
540 
541   return Error::success();
542 }
543 
parseLinkingSectionComdat(ReadContext & Ctx)544 Error WasmObjectFile::parseLinkingSectionComdat(ReadContext &Ctx) {
545   uint32_t ComdatCount = readVaruint32(Ctx);
546   StringSet<> ComdatSet;
547   for (unsigned ComdatIndex = 0; ComdatIndex < ComdatCount; ++ComdatIndex) {
548     StringRef Name = readString(Ctx);
549     if (Name.empty() || !ComdatSet.insert(Name).second)
550       return make_error<GenericBinaryError>("Bad/duplicate COMDAT name " + Twine(Name),
551                                             object_error::parse_failed);
552     LinkingData.Comdats.emplace_back(Name);
553     uint32_t Flags = readVaruint32(Ctx);
554     if (Flags != 0)
555       return make_error<GenericBinaryError>("Unsupported COMDAT flags",
556                                             object_error::parse_failed);
557 
558     uint32_t EntryCount = readVaruint32(Ctx);
559     while (EntryCount--) {
560       unsigned Kind = readVaruint32(Ctx);
561       unsigned Index = readVaruint32(Ctx);
562       switch (Kind) {
563       default:
564         return make_error<GenericBinaryError>("Invalid COMDAT entry type",
565                                               object_error::parse_failed);
566       case wasm::WASM_COMDAT_DATA:
567         if (Index >= DataSegments.size())
568           return make_error<GenericBinaryError>("COMDAT data index out of range",
569                                                 object_error::parse_failed);
570         if (DataSegments[Index].Data.Comdat != UINT32_MAX)
571           return make_error<GenericBinaryError>("Data segment in two COMDATs",
572                                                 object_error::parse_failed);
573         DataSegments[Index].Data.Comdat = ComdatIndex;
574         break;
575       case wasm::WASM_COMDAT_FUNCTION:
576         if (!isDefinedFunctionIndex(Index))
577           return make_error<GenericBinaryError>("COMDAT function index out of range",
578                                                 object_error::parse_failed);
579         if (getDefinedFunction(Index).Comdat != UINT32_MAX)
580           return make_error<GenericBinaryError>("Function in two COMDATs",
581                                                 object_error::parse_failed);
582         getDefinedFunction(Index).Comdat = ComdatIndex;
583         break;
584       }
585     }
586   }
587   return Error::success();
588 }
589 
parseRelocSection(StringRef Name,ReadContext & Ctx)590 Error WasmObjectFile::parseRelocSection(StringRef Name, ReadContext &Ctx) {
591   uint32_t SectionIndex = readVaruint32(Ctx);
592   if (SectionIndex >= Sections.size())
593     return make_error<GenericBinaryError>("Invalid section index",
594                                           object_error::parse_failed);
595   WasmSection& Section = Sections[SectionIndex];
596   uint32_t RelocCount = readVaruint32(Ctx);
597   uint32_t EndOffset = Section.Content.size();
598   while (RelocCount--) {
599     wasm::WasmRelocation Reloc = {};
600     Reloc.Type = readVaruint32(Ctx);
601     Reloc.Offset = readVaruint32(Ctx);
602     Reloc.Index = readVaruint32(Ctx);
603     switch (Reloc.Type) {
604     case wasm::R_WEBASSEMBLY_FUNCTION_INDEX_LEB:
605     case wasm::R_WEBASSEMBLY_TABLE_INDEX_SLEB:
606     case wasm::R_WEBASSEMBLY_TABLE_INDEX_I32:
607       if (!isValidFunctionSymbol(Reloc.Index))
608         return make_error<GenericBinaryError>("Bad relocation function index",
609                                               object_error::parse_failed);
610       break;
611     case wasm::R_WEBASSEMBLY_TYPE_INDEX_LEB:
612       if (Reloc.Index >= Signatures.size())
613         return make_error<GenericBinaryError>("Bad relocation type index",
614                                               object_error::parse_failed);
615       break;
616     case wasm::R_WEBASSEMBLY_GLOBAL_INDEX_LEB:
617       if (!isValidGlobalSymbol(Reloc.Index))
618         return make_error<GenericBinaryError>("Bad relocation global index",
619                                               object_error::parse_failed);
620       break;
621     case wasm::R_WEBASSEMBLY_MEMORY_ADDR_LEB:
622     case wasm::R_WEBASSEMBLY_MEMORY_ADDR_SLEB:
623     case wasm::R_WEBASSEMBLY_MEMORY_ADDR_I32:
624       if (!isValidDataSymbol(Reloc.Index))
625         return make_error<GenericBinaryError>("Bad relocation data index",
626                                               object_error::parse_failed);
627       Reloc.Addend = readVarint32(Ctx);
628       break;
629     case wasm::R_WEBASSEMBLY_FUNCTION_OFFSET_I32:
630       if (!isValidFunctionSymbol(Reloc.Index))
631         return make_error<GenericBinaryError>("Bad relocation function index",
632                                               object_error::parse_failed);
633       Reloc.Addend = readVarint32(Ctx);
634       break;
635     case wasm::R_WEBASSEMBLY_SECTION_OFFSET_I32:
636       if (!isValidSectionSymbol(Reloc.Index))
637         return make_error<GenericBinaryError>("Bad relocation section index",
638                                               object_error::parse_failed);
639       Reloc.Addend = readVarint32(Ctx);
640       break;
641     default:
642       return make_error<GenericBinaryError>("Bad relocation type: " +
643                                                 Twine(Reloc.Type),
644                                             object_error::parse_failed);
645     }
646 
647     // Relocations must fit inside the section, and must appear in order.  They
648     // also shouldn't overlap a function/element boundary, but we don't bother
649     // to check that.
650     uint64_t Size = 5;
651     if (Reloc.Type == wasm::R_WEBASSEMBLY_TABLE_INDEX_I32 ||
652         Reloc.Type == wasm::R_WEBASSEMBLY_MEMORY_ADDR_I32 ||
653         Reloc.Type == wasm::R_WEBASSEMBLY_SECTION_OFFSET_I32 ||
654         Reloc.Type == wasm::R_WEBASSEMBLY_FUNCTION_OFFSET_I32)
655       Size = 4;
656     if (Reloc.Offset + Size > EndOffset)
657       return make_error<GenericBinaryError>("Bad relocation offset",
658                                             object_error::parse_failed);
659 
660     Section.Relocations.push_back(Reloc);
661   }
662   if (Ctx.Ptr != Ctx.End)
663     return make_error<GenericBinaryError>("Reloc section ended prematurely",
664                                           object_error::parse_failed);
665   return Error::success();
666 }
667 
parseCustomSection(WasmSection & Sec,ReadContext & Ctx)668 Error WasmObjectFile::parseCustomSection(WasmSection &Sec, ReadContext &Ctx) {
669   if (Sec.Name == "name") {
670     if (Error Err = parseNameSection(Ctx))
671       return Err;
672   } else if (Sec.Name == "linking") {
673     if (Error Err = parseLinkingSection(Ctx))
674       return Err;
675   } else if (Sec.Name.startswith("reloc.")) {
676     if (Error Err = parseRelocSection(Sec.Name, Ctx))
677       return Err;
678   }
679   return Error::success();
680 }
681 
parseTypeSection(ReadContext & Ctx)682 Error WasmObjectFile::parseTypeSection(ReadContext &Ctx) {
683   uint32_t Count = readVaruint32(Ctx);
684   Signatures.reserve(Count);
685   while (Count--) {
686     wasm::WasmSignature Sig;
687     Sig.ReturnType = wasm::WASM_TYPE_NORESULT;
688     uint8_t Form = readUint8(Ctx);
689     if (Form != wasm::WASM_TYPE_FUNC) {
690       return make_error<GenericBinaryError>("Invalid signature type",
691                                             object_error::parse_failed);
692     }
693     uint32_t ParamCount = readVaruint32(Ctx);
694     Sig.ParamTypes.reserve(ParamCount);
695     while (ParamCount--) {
696       uint32_t ParamType = readUint8(Ctx);
697       Sig.ParamTypes.push_back(ParamType);
698     }
699     uint32_t ReturnCount = readVaruint32(Ctx);
700     if (ReturnCount) {
701       if (ReturnCount != 1) {
702         return make_error<GenericBinaryError>(
703             "Multiple return types not supported", object_error::parse_failed);
704       }
705       Sig.ReturnType = readUint8(Ctx);
706     }
707     Signatures.push_back(Sig);
708   }
709   if (Ctx.Ptr != Ctx.End)
710     return make_error<GenericBinaryError>("Type section ended prematurely",
711                                           object_error::parse_failed);
712   return Error::success();
713 }
714 
parseImportSection(ReadContext & Ctx)715 Error WasmObjectFile::parseImportSection(ReadContext &Ctx) {
716   uint32_t Count = readVaruint32(Ctx);
717   Imports.reserve(Count);
718   for (uint32_t i = 0; i < Count; i++) {
719     wasm::WasmImport Im;
720     Im.Module = readString(Ctx);
721     Im.Field = readString(Ctx);
722     Im.Kind = readUint8(Ctx);
723     switch (Im.Kind) {
724     case wasm::WASM_EXTERNAL_FUNCTION:
725       NumImportedFunctions++;
726       Im.SigIndex = readVaruint32(Ctx);
727       break;
728     case wasm::WASM_EXTERNAL_GLOBAL:
729       NumImportedGlobals++;
730       Im.Global.Type = readUint8(Ctx);
731       Im.Global.Mutable = readVaruint1(Ctx);
732       break;
733     case wasm::WASM_EXTERNAL_MEMORY:
734       Im.Memory = readLimits(Ctx);
735       break;
736     case wasm::WASM_EXTERNAL_TABLE:
737       Im.Table = readTable(Ctx);
738       if (Im.Table.ElemType != wasm::WASM_TYPE_ANYFUNC)
739         return make_error<GenericBinaryError>("Invalid table element type",
740                                               object_error::parse_failed);
741       break;
742     default:
743       return make_error<GenericBinaryError>(
744           "Unexpected import kind", object_error::parse_failed);
745     }
746     Imports.push_back(Im);
747   }
748   if (Ctx.Ptr != Ctx.End)
749     return make_error<GenericBinaryError>("Import section ended prematurely",
750                                           object_error::parse_failed);
751   return Error::success();
752 }
753 
parseFunctionSection(ReadContext & Ctx)754 Error WasmObjectFile::parseFunctionSection(ReadContext &Ctx) {
755   uint32_t Count = readVaruint32(Ctx);
756   FunctionTypes.reserve(Count);
757   uint32_t NumTypes = Signatures.size();
758   while (Count--) {
759     uint32_t Type = readVaruint32(Ctx);
760     if (Type >= NumTypes)
761       return make_error<GenericBinaryError>("Invalid function type",
762                                             object_error::parse_failed);
763     FunctionTypes.push_back(Type);
764   }
765   if (Ctx.Ptr != Ctx.End)
766     return make_error<GenericBinaryError>("Function section ended prematurely",
767                                           object_error::parse_failed);
768   return Error::success();
769 }
770 
parseTableSection(ReadContext & Ctx)771 Error WasmObjectFile::parseTableSection(ReadContext &Ctx) {
772   uint32_t Count = readVaruint32(Ctx);
773   Tables.reserve(Count);
774   while (Count--) {
775     Tables.push_back(readTable(Ctx));
776     if (Tables.back().ElemType != wasm::WASM_TYPE_ANYFUNC) {
777       return make_error<GenericBinaryError>("Invalid table element type",
778                                             object_error::parse_failed);
779     }
780   }
781   if (Ctx.Ptr != Ctx.End)
782     return make_error<GenericBinaryError>("Table section ended prematurely",
783                                           object_error::parse_failed);
784   return Error::success();
785 }
786 
parseMemorySection(ReadContext & Ctx)787 Error WasmObjectFile::parseMemorySection(ReadContext &Ctx) {
788   uint32_t Count = readVaruint32(Ctx);
789   Memories.reserve(Count);
790   while (Count--) {
791     Memories.push_back(readLimits(Ctx));
792   }
793   if (Ctx.Ptr != Ctx.End)
794     return make_error<GenericBinaryError>("Memory section ended prematurely",
795                                           object_error::parse_failed);
796   return Error::success();
797 }
798 
parseGlobalSection(ReadContext & Ctx)799 Error WasmObjectFile::parseGlobalSection(ReadContext &Ctx) {
800   GlobalSection = Sections.size();
801   uint32_t Count = readVaruint32(Ctx);
802   Globals.reserve(Count);
803   while (Count--) {
804     wasm::WasmGlobal Global;
805     Global.Index = NumImportedGlobals + Globals.size();
806     Global.Type.Type = readUint8(Ctx);
807     Global.Type.Mutable = readVaruint1(Ctx);
808     if (Error Err = readInitExpr(Global.InitExpr, Ctx))
809       return Err;
810     Globals.push_back(Global);
811   }
812   if (Ctx.Ptr != Ctx.End)
813     return make_error<GenericBinaryError>("Global section ended prematurely",
814                                           object_error::parse_failed);
815   return Error::success();
816 }
817 
parseExportSection(ReadContext & Ctx)818 Error WasmObjectFile::parseExportSection(ReadContext &Ctx) {
819   uint32_t Count = readVaruint32(Ctx);
820   Exports.reserve(Count);
821   for (uint32_t i = 0; i < Count; i++) {
822     wasm::WasmExport Ex;
823     Ex.Name = readString(Ctx);
824     Ex.Kind = readUint8(Ctx);
825     Ex.Index = readVaruint32(Ctx);
826     switch (Ex.Kind) {
827     case wasm::WASM_EXTERNAL_FUNCTION:
828       if (!isValidFunctionIndex(Ex.Index))
829         return make_error<GenericBinaryError>("Invalid function export",
830                                               object_error::parse_failed);
831       break;
832     case wasm::WASM_EXTERNAL_GLOBAL:
833       if (!isValidGlobalIndex(Ex.Index))
834         return make_error<GenericBinaryError>("Invalid global export",
835                                               object_error::parse_failed);
836       break;
837     case wasm::WASM_EXTERNAL_MEMORY:
838     case wasm::WASM_EXTERNAL_TABLE:
839       break;
840     default:
841       return make_error<GenericBinaryError>(
842           "Unexpected export kind", object_error::parse_failed);
843     }
844     Exports.push_back(Ex);
845   }
846   if (Ctx.Ptr != Ctx.End)
847     return make_error<GenericBinaryError>("Export section ended prematurely",
848                                           object_error::parse_failed);
849   return Error::success();
850 }
851 
isValidFunctionIndex(uint32_t Index) const852 bool WasmObjectFile::isValidFunctionIndex(uint32_t Index) const {
853   return Index < NumImportedFunctions + FunctionTypes.size();
854 }
855 
isDefinedFunctionIndex(uint32_t Index) const856 bool WasmObjectFile::isDefinedFunctionIndex(uint32_t Index) const {
857   return Index >= NumImportedFunctions && isValidFunctionIndex(Index);
858 }
859 
isValidGlobalIndex(uint32_t Index) const860 bool WasmObjectFile::isValidGlobalIndex(uint32_t Index) const {
861   return Index < NumImportedGlobals + Globals.size();
862 }
863 
isDefinedGlobalIndex(uint32_t Index) const864 bool WasmObjectFile::isDefinedGlobalIndex(uint32_t Index) const {
865   return Index >= NumImportedGlobals && isValidGlobalIndex(Index);
866 }
867 
isValidFunctionSymbol(uint32_t Index) const868 bool WasmObjectFile::isValidFunctionSymbol(uint32_t Index) const {
869   return Index < Symbols.size() && Symbols[Index].isTypeFunction();
870 }
871 
isValidGlobalSymbol(uint32_t Index) const872 bool WasmObjectFile::isValidGlobalSymbol(uint32_t Index) const {
873   return Index < Symbols.size() && Symbols[Index].isTypeGlobal();
874 }
875 
isValidDataSymbol(uint32_t Index) const876 bool WasmObjectFile::isValidDataSymbol(uint32_t Index) const {
877   return Index < Symbols.size() && Symbols[Index].isTypeData();
878 }
879 
isValidSectionSymbol(uint32_t Index) const880 bool WasmObjectFile::isValidSectionSymbol(uint32_t Index) const {
881   return Index < Symbols.size() && Symbols[Index].isTypeSection();
882 }
883 
getDefinedFunction(uint32_t Index)884 wasm::WasmFunction &WasmObjectFile::getDefinedFunction(uint32_t Index) {
885   assert(isDefinedFunctionIndex(Index));
886   return Functions[Index - NumImportedFunctions];
887 }
888 
getDefinedGlobal(uint32_t Index)889 wasm::WasmGlobal &WasmObjectFile::getDefinedGlobal(uint32_t Index) {
890   assert(isDefinedGlobalIndex(Index));
891   return Globals[Index - NumImportedGlobals];
892 }
893 
parseStartSection(ReadContext & Ctx)894 Error WasmObjectFile::parseStartSection(ReadContext &Ctx) {
895   StartFunction = readVaruint32(Ctx);
896   if (!isValidFunctionIndex(StartFunction))
897     return make_error<GenericBinaryError>("Invalid start function",
898                                           object_error::parse_failed);
899   return Error::success();
900 }
901 
parseCodeSection(ReadContext & Ctx)902 Error WasmObjectFile::parseCodeSection(ReadContext &Ctx) {
903   CodeSection = Sections.size();
904   uint32_t FunctionCount = readVaruint32(Ctx);
905   if (FunctionCount != FunctionTypes.size()) {
906     return make_error<GenericBinaryError>("Invalid function count",
907                                           object_error::parse_failed);
908   }
909 
910   while (FunctionCount--) {
911     wasm::WasmFunction Function;
912     const uint8_t *FunctionStart = Ctx.Ptr;
913     uint32_t Size = readVaruint32(Ctx);
914     const uint8_t *FunctionEnd = Ctx.Ptr + Size;
915 
916     Function.CodeOffset = Ctx.Ptr - FunctionStart;
917     Function.Index = NumImportedFunctions + Functions.size();
918     Function.CodeSectionOffset = FunctionStart - Ctx.Start;
919     Function.Size = FunctionEnd - FunctionStart;
920 
921     uint32_t NumLocalDecls = readVaruint32(Ctx);
922     Function.Locals.reserve(NumLocalDecls);
923     while (NumLocalDecls--) {
924       wasm::WasmLocalDecl Decl;
925       Decl.Count = readVaruint32(Ctx);
926       Decl.Type = readUint8(Ctx);
927       Function.Locals.push_back(Decl);
928     }
929 
930     uint32_t BodySize = FunctionEnd - Ctx.Ptr;
931     Function.Body = ArrayRef<uint8_t>(Ctx.Ptr, BodySize);
932     // This will be set later when reading in the linking metadata section.
933     Function.Comdat = UINT32_MAX;
934     Ctx.Ptr += BodySize;
935     assert(Ctx.Ptr == FunctionEnd);
936     Functions.push_back(Function);
937   }
938   if (Ctx.Ptr != Ctx.End)
939     return make_error<GenericBinaryError>("Code section ended prematurely",
940                                           object_error::parse_failed);
941   return Error::success();
942 }
943 
parseElemSection(ReadContext & Ctx)944 Error WasmObjectFile::parseElemSection(ReadContext &Ctx) {
945   uint32_t Count = readVaruint32(Ctx);
946   ElemSegments.reserve(Count);
947   while (Count--) {
948     wasm::WasmElemSegment Segment;
949     Segment.TableIndex = readVaruint32(Ctx);
950     if (Segment.TableIndex != 0) {
951       return make_error<GenericBinaryError>("Invalid TableIndex",
952                                             object_error::parse_failed);
953     }
954     if (Error Err = readInitExpr(Segment.Offset, Ctx))
955       return Err;
956     uint32_t NumElems = readVaruint32(Ctx);
957     while (NumElems--) {
958       Segment.Functions.push_back(readVaruint32(Ctx));
959     }
960     ElemSegments.push_back(Segment);
961   }
962   if (Ctx.Ptr != Ctx.End)
963     return make_error<GenericBinaryError>("Elem section ended prematurely",
964                                           object_error::parse_failed);
965   return Error::success();
966 }
967 
parseDataSection(ReadContext & Ctx)968 Error WasmObjectFile::parseDataSection(ReadContext &Ctx) {
969   DataSection = Sections.size();
970   uint32_t Count = readVaruint32(Ctx);
971   DataSegments.reserve(Count);
972   while (Count--) {
973     WasmSegment Segment;
974     Segment.Data.MemoryIndex = readVaruint32(Ctx);
975     if (Error Err = readInitExpr(Segment.Data.Offset, Ctx))
976       return Err;
977     uint32_t Size = readVaruint32(Ctx);
978     if (Size > (size_t)(Ctx.End - Ctx.Ptr))
979       return make_error<GenericBinaryError>("Invalid segment size",
980                                             object_error::parse_failed);
981     Segment.Data.Content = ArrayRef<uint8_t>(Ctx.Ptr, Size);
982     // The rest of these Data fields are set later, when reading in the linking
983     // metadata section.
984     Segment.Data.Alignment = 0;
985     Segment.Data.Flags = 0;
986     Segment.Data.Comdat = UINT32_MAX;
987     Segment.SectionOffset = Ctx.Ptr - Ctx.Start;
988     Ctx.Ptr += Size;
989     DataSegments.push_back(Segment);
990   }
991   if (Ctx.Ptr != Ctx.End)
992     return make_error<GenericBinaryError>("Data section ended prematurely",
993                                           object_error::parse_failed);
994   return Error::success();
995 }
996 
getPtr(size_t Offset) const997 const uint8_t *WasmObjectFile::getPtr(size_t Offset) const {
998   return reinterpret_cast<const uint8_t *>(getData().data() + Offset);
999 }
1000 
getHeader() const1001 const wasm::WasmObjectHeader &WasmObjectFile::getHeader() const {
1002   return Header;
1003 }
1004 
moveSymbolNext(DataRefImpl & Symb) const1005 void WasmObjectFile::moveSymbolNext(DataRefImpl &Symb) const { Symb.d.a++; }
1006 
getSymbolFlags(DataRefImpl Symb) const1007 uint32_t WasmObjectFile::getSymbolFlags(DataRefImpl Symb) const {
1008   uint32_t Result = SymbolRef::SF_None;
1009   const WasmSymbol &Sym = getWasmSymbol(Symb);
1010 
1011   LLVM_DEBUG(dbgs() << "getSymbolFlags: ptr=" << &Sym << " " << Sym << "\n");
1012   if (Sym.isBindingWeak())
1013     Result |= SymbolRef::SF_Weak;
1014   if (!Sym.isBindingLocal())
1015     Result |= SymbolRef::SF_Global;
1016   if (Sym.isHidden())
1017     Result |= SymbolRef::SF_Hidden;
1018   if (!Sym.isDefined())
1019     Result |= SymbolRef::SF_Undefined;
1020   if (Sym.isTypeFunction())
1021     Result |= SymbolRef::SF_Executable;
1022   return Result;
1023 }
1024 
symbol_begin() const1025 basic_symbol_iterator WasmObjectFile::symbol_begin() const {
1026   DataRefImpl Ref;
1027   Ref.d.a = 0;
1028   return BasicSymbolRef(Ref, this);
1029 }
1030 
symbol_end() const1031 basic_symbol_iterator WasmObjectFile::symbol_end() const {
1032   DataRefImpl Ref;
1033   Ref.d.a = Symbols.size();
1034   return BasicSymbolRef(Ref, this);
1035 }
1036 
getWasmSymbol(const DataRefImpl & Symb) const1037 const WasmSymbol &WasmObjectFile::getWasmSymbol(const DataRefImpl &Symb) const {
1038   return Symbols[Symb.d.a];
1039 }
1040 
getWasmSymbol(const SymbolRef & Symb) const1041 const WasmSymbol &WasmObjectFile::getWasmSymbol(const SymbolRef &Symb) const {
1042   return getWasmSymbol(Symb.getRawDataRefImpl());
1043 }
1044 
getSymbolName(DataRefImpl Symb) const1045 Expected<StringRef> WasmObjectFile::getSymbolName(DataRefImpl Symb) const {
1046   return getWasmSymbol(Symb).Info.Name;
1047 }
1048 
getSymbolAddress(DataRefImpl Symb) const1049 Expected<uint64_t> WasmObjectFile::getSymbolAddress(DataRefImpl Symb) const {
1050   return getSymbolValue(Symb);
1051 }
1052 
getWasmSymbolValue(const WasmSymbol & Sym) const1053 uint64_t WasmObjectFile::getWasmSymbolValue(const WasmSymbol& Sym) const {
1054   switch (Sym.Info.Kind) {
1055   case wasm::WASM_SYMBOL_TYPE_FUNCTION:
1056   case wasm::WASM_SYMBOL_TYPE_GLOBAL:
1057     return Sym.Info.ElementIndex;
1058   case wasm::WASM_SYMBOL_TYPE_DATA: {
1059     // The value of a data symbol is the segment offset, plus the symbol
1060     // offset within the segment.
1061     uint32_t SegmentIndex = Sym.Info.DataRef.Segment;
1062     const wasm::WasmDataSegment &Segment = DataSegments[SegmentIndex].Data;
1063     assert(Segment.Offset.Opcode == wasm::WASM_OPCODE_I32_CONST);
1064     return Segment.Offset.Value.Int32 + Sym.Info.DataRef.Offset;
1065   }
1066   case wasm::WASM_SYMBOL_TYPE_SECTION:
1067     return 0;
1068   }
1069   llvm_unreachable("invalid symbol type");
1070 }
1071 
getSymbolValueImpl(DataRefImpl Symb) const1072 uint64_t WasmObjectFile::getSymbolValueImpl(DataRefImpl Symb) const {
1073   return getWasmSymbolValue(getWasmSymbol(Symb));
1074 }
1075 
getSymbolAlignment(DataRefImpl Symb) const1076 uint32_t WasmObjectFile::getSymbolAlignment(DataRefImpl Symb) const {
1077   llvm_unreachable("not yet implemented");
1078   return 0;
1079 }
1080 
getCommonSymbolSizeImpl(DataRefImpl Symb) const1081 uint64_t WasmObjectFile::getCommonSymbolSizeImpl(DataRefImpl Symb) const {
1082   llvm_unreachable("not yet implemented");
1083   return 0;
1084 }
1085 
1086 Expected<SymbolRef::Type>
getSymbolType(DataRefImpl Symb) const1087 WasmObjectFile::getSymbolType(DataRefImpl Symb) const {
1088   const WasmSymbol &Sym = getWasmSymbol(Symb);
1089 
1090   switch (Sym.Info.Kind) {
1091   case wasm::WASM_SYMBOL_TYPE_FUNCTION:
1092     return SymbolRef::ST_Function;
1093   case wasm::WASM_SYMBOL_TYPE_GLOBAL:
1094     return SymbolRef::ST_Other;
1095   case wasm::WASM_SYMBOL_TYPE_DATA:
1096     return SymbolRef::ST_Data;
1097   case wasm::WASM_SYMBOL_TYPE_SECTION:
1098     return SymbolRef::ST_Debug;
1099   }
1100 
1101   llvm_unreachable("Unknown WasmSymbol::SymbolType");
1102   return SymbolRef::ST_Other;
1103 }
1104 
1105 Expected<section_iterator>
getSymbolSection(DataRefImpl Symb) const1106 WasmObjectFile::getSymbolSection(DataRefImpl Symb) const {
1107   const WasmSymbol& Sym = getWasmSymbol(Symb);
1108   if (Sym.isUndefined())
1109     return section_end();
1110 
1111   DataRefImpl Ref;
1112   switch (Sym.Info.Kind) {
1113   case wasm::WASM_SYMBOL_TYPE_FUNCTION:
1114     Ref.d.a = CodeSection;
1115     break;
1116   case wasm::WASM_SYMBOL_TYPE_GLOBAL:
1117     Ref.d.a = GlobalSection;
1118     break;
1119   case wasm::WASM_SYMBOL_TYPE_DATA:
1120     Ref.d.a = DataSection;
1121     break;
1122   case wasm::WASM_SYMBOL_TYPE_SECTION: {
1123     Ref.d.a = Sym.Info.ElementIndex;
1124     break;
1125   }
1126   default:
1127     llvm_unreachable("Unknown WasmSymbol::SymbolType");
1128   }
1129   return section_iterator(SectionRef(Ref, this));
1130 }
1131 
moveSectionNext(DataRefImpl & Sec) const1132 void WasmObjectFile::moveSectionNext(DataRefImpl &Sec) const { Sec.d.a++; }
1133 
getSectionName(DataRefImpl Sec,StringRef & Res) const1134 std::error_code WasmObjectFile::getSectionName(DataRefImpl Sec,
1135                                                StringRef &Res) const {
1136   const WasmSection &S = Sections[Sec.d.a];
1137 #define ECase(X)                                                               \
1138   case wasm::WASM_SEC_##X:                                                     \
1139     Res = #X;                                                                  \
1140     break
1141   switch (S.Type) {
1142     ECase(TYPE);
1143     ECase(IMPORT);
1144     ECase(FUNCTION);
1145     ECase(TABLE);
1146     ECase(MEMORY);
1147     ECase(GLOBAL);
1148     ECase(EXPORT);
1149     ECase(START);
1150     ECase(ELEM);
1151     ECase(CODE);
1152     ECase(DATA);
1153   case wasm::WASM_SEC_CUSTOM:
1154     Res = S.Name;
1155     break;
1156   default:
1157     return object_error::invalid_section_index;
1158   }
1159 #undef ECase
1160   return std::error_code();
1161 }
1162 
getSectionAddress(DataRefImpl Sec) const1163 uint64_t WasmObjectFile::getSectionAddress(DataRefImpl Sec) const { return 0; }
1164 
getSectionIndex(DataRefImpl Sec) const1165 uint64_t WasmObjectFile::getSectionIndex(DataRefImpl Sec) const {
1166   return Sec.d.a;
1167 }
1168 
getSectionSize(DataRefImpl Sec) const1169 uint64_t WasmObjectFile::getSectionSize(DataRefImpl Sec) const {
1170   const WasmSection &S = Sections[Sec.d.a];
1171   return S.Content.size();
1172 }
1173 
getSectionContents(DataRefImpl Sec,StringRef & Res) const1174 std::error_code WasmObjectFile::getSectionContents(DataRefImpl Sec,
1175                                                    StringRef &Res) const {
1176   const WasmSection &S = Sections[Sec.d.a];
1177   // This will never fail since wasm sections can never be empty (user-sections
1178   // must have a name and non-user sections each have a defined structure).
1179   Res = StringRef(reinterpret_cast<const char *>(S.Content.data()),
1180                   S.Content.size());
1181   return std::error_code();
1182 }
1183 
getSectionAlignment(DataRefImpl Sec) const1184 uint64_t WasmObjectFile::getSectionAlignment(DataRefImpl Sec) const {
1185   return 1;
1186 }
1187 
isSectionCompressed(DataRefImpl Sec) const1188 bool WasmObjectFile::isSectionCompressed(DataRefImpl Sec) const {
1189   return false;
1190 }
1191 
isSectionText(DataRefImpl Sec) const1192 bool WasmObjectFile::isSectionText(DataRefImpl Sec) const {
1193   return getWasmSection(Sec).Type == wasm::WASM_SEC_CODE;
1194 }
1195 
isSectionData(DataRefImpl Sec) const1196 bool WasmObjectFile::isSectionData(DataRefImpl Sec) const {
1197   return getWasmSection(Sec).Type == wasm::WASM_SEC_DATA;
1198 }
1199 
isSectionBSS(DataRefImpl Sec) const1200 bool WasmObjectFile::isSectionBSS(DataRefImpl Sec) const { return false; }
1201 
isSectionVirtual(DataRefImpl Sec) const1202 bool WasmObjectFile::isSectionVirtual(DataRefImpl Sec) const { return false; }
1203 
isSectionBitcode(DataRefImpl Sec) const1204 bool WasmObjectFile::isSectionBitcode(DataRefImpl Sec) const { return false; }
1205 
section_rel_begin(DataRefImpl Ref) const1206 relocation_iterator WasmObjectFile::section_rel_begin(DataRefImpl Ref) const {
1207   DataRefImpl RelocRef;
1208   RelocRef.d.a = Ref.d.a;
1209   RelocRef.d.b = 0;
1210   return relocation_iterator(RelocationRef(RelocRef, this));
1211 }
1212 
section_rel_end(DataRefImpl Ref) const1213 relocation_iterator WasmObjectFile::section_rel_end(DataRefImpl Ref) const {
1214   const WasmSection &Sec = getWasmSection(Ref);
1215   DataRefImpl RelocRef;
1216   RelocRef.d.a = Ref.d.a;
1217   RelocRef.d.b = Sec.Relocations.size();
1218   return relocation_iterator(RelocationRef(RelocRef, this));
1219 }
1220 
moveRelocationNext(DataRefImpl & Rel) const1221 void WasmObjectFile::moveRelocationNext(DataRefImpl &Rel) const {
1222   Rel.d.b++;
1223 }
1224 
getRelocationOffset(DataRefImpl Ref) const1225 uint64_t WasmObjectFile::getRelocationOffset(DataRefImpl Ref) const {
1226   const wasm::WasmRelocation &Rel = getWasmRelocation(Ref);
1227   return Rel.Offset;
1228 }
1229 
getRelocationSymbol(DataRefImpl Ref) const1230 symbol_iterator WasmObjectFile::getRelocationSymbol(DataRefImpl Ref) const {
1231   const wasm::WasmRelocation &Rel = getWasmRelocation(Ref);
1232   if (Rel.Type == wasm::R_WEBASSEMBLY_TYPE_INDEX_LEB)
1233     return symbol_end();
1234   DataRefImpl Sym;
1235   Sym.d.a = Rel.Index;
1236   Sym.d.b = 0;
1237   return symbol_iterator(SymbolRef(Sym, this));
1238 }
1239 
getRelocationType(DataRefImpl Ref) const1240 uint64_t WasmObjectFile::getRelocationType(DataRefImpl Ref) const {
1241   const wasm::WasmRelocation &Rel = getWasmRelocation(Ref);
1242   return Rel.Type;
1243 }
1244 
getRelocationTypeName(DataRefImpl Ref,SmallVectorImpl<char> & Result) const1245 void WasmObjectFile::getRelocationTypeName(
1246     DataRefImpl Ref, SmallVectorImpl<char> &Result) const {
1247   const wasm::WasmRelocation& Rel = getWasmRelocation(Ref);
1248   StringRef Res = "Unknown";
1249 
1250 #define WASM_RELOC(name, value)  \
1251   case wasm::name:              \
1252     Res = #name;               \
1253     break;
1254 
1255   switch (Rel.Type) {
1256 #include "llvm/BinaryFormat/WasmRelocs.def"
1257   }
1258 
1259 #undef WASM_RELOC
1260 
1261   Result.append(Res.begin(), Res.end());
1262 }
1263 
section_begin() const1264 section_iterator WasmObjectFile::section_begin() const {
1265   DataRefImpl Ref;
1266   Ref.d.a = 0;
1267   return section_iterator(SectionRef(Ref, this));
1268 }
1269 
section_end() const1270 section_iterator WasmObjectFile::section_end() const {
1271   DataRefImpl Ref;
1272   Ref.d.a = Sections.size();
1273   return section_iterator(SectionRef(Ref, this));
1274 }
1275 
getBytesInAddress() const1276 uint8_t WasmObjectFile::getBytesInAddress() const { return 4; }
1277 
getFileFormatName() const1278 StringRef WasmObjectFile::getFileFormatName() const { return "WASM"; }
1279 
getArch() const1280 Triple::ArchType WasmObjectFile::getArch() const { return Triple::wasm32; }
1281 
getFeatures() const1282 SubtargetFeatures WasmObjectFile::getFeatures() const {
1283   return SubtargetFeatures();
1284 }
1285 
isRelocatableObject() const1286 bool WasmObjectFile::isRelocatableObject() const {
1287   return HasLinkingSection;
1288 }
1289 
getWasmSection(DataRefImpl Ref) const1290 const WasmSection &WasmObjectFile::getWasmSection(DataRefImpl Ref) const {
1291   assert(Ref.d.a < Sections.size());
1292   return Sections[Ref.d.a];
1293 }
1294 
1295 const WasmSection &
getWasmSection(const SectionRef & Section) const1296 WasmObjectFile::getWasmSection(const SectionRef &Section) const {
1297   return getWasmSection(Section.getRawDataRefImpl());
1298 }
1299 
1300 const wasm::WasmRelocation &
getWasmRelocation(const RelocationRef & Ref) const1301 WasmObjectFile::getWasmRelocation(const RelocationRef &Ref) const {
1302   return getWasmRelocation(Ref.getRawDataRefImpl());
1303 }
1304 
1305 const wasm::WasmRelocation &
getWasmRelocation(DataRefImpl Ref) const1306 WasmObjectFile::getWasmRelocation(DataRefImpl Ref) const {
1307   assert(Ref.d.a < Sections.size());
1308   const WasmSection& Sec = Sections[Ref.d.a];
1309   assert(Ref.d.b < Sec.Relocations.size());
1310   return Sec.Relocations[Ref.d.b];
1311 }
1312