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/STLExtras.h"
12 #include "llvm/ADT/StringRef.h"
13 #include "llvm/ADT/Triple.h"
14 #include "llvm/MC/SubtargetFeature.h"
15 #include "llvm/Object/Binary.h"
16 #include "llvm/Object/Error.h"
17 #include "llvm/Object/ObjectFile.h"
18 #include "llvm/Object/SymbolicFile.h"
19 #include "llvm/Object/Wasm.h"
20 #include "llvm/Support/Endian.h"
21 #include "llvm/Support/Error.h"
22 #include "llvm/Support/ErrorHandling.h"
23 #include "llvm/Support/LEB128.h"
24 #include "llvm/Support/Wasm.h"
25 #include <algorithm>
26 #include <cassert>
27 #include <cstdint>
28 #include <cstring>
29 #include <system_error>
30 
31 using namespace llvm;
32 using namespace object;
33 
34 Expected<std::unique_ptr<WasmObjectFile>>
35 ObjectFile::createWasmObjectFile(MemoryBufferRef Buffer) {
36   Error Err = Error::success();
37   auto ObjectFile = llvm::make_unique<WasmObjectFile>(Buffer, Err);
38   if (Err)
39     return std::move(Err);
40 
41   return std::move(ObjectFile);
42 }
43 
44 #define VARINT7_MAX ((1<<7)-1)
45 #define VARINT7_MIN (-(1<<7))
46 #define VARUINT7_MAX (1<<7)
47 #define VARUINT1_MAX (1)
48 
49 static uint8_t readUint8(const uint8_t *&Ptr) { return *Ptr++; }
50 
51 static uint32_t readUint32(const uint8_t *&Ptr) {
52   uint32_t Result = support::endian::read32le(Ptr);
53   Ptr += sizeof(Result);
54   return Result;
55 }
56 
57 static int32_t readFloat32(const uint8_t *&Ptr) {
58   int32_t Result = 0;
59   memcpy(&Result, Ptr, sizeof(Result));
60   Ptr += sizeof(Result);
61   return Result;
62 }
63 
64 static int64_t readFloat64(const uint8_t *&Ptr) {
65   int64_t Result = 0;
66   memcpy(&Result, Ptr, sizeof(Result));
67   Ptr += sizeof(Result);
68   return Result;
69 }
70 
71 static uint64_t readULEB128(const uint8_t *&Ptr) {
72   unsigned Count;
73   uint64_t Result = decodeULEB128(Ptr, &Count);
74   Ptr += Count;
75   return Result;
76 }
77 
78 static StringRef readString(const uint8_t *&Ptr) {
79   uint32_t StringLen = readULEB128(Ptr);
80   StringRef Return = StringRef(reinterpret_cast<const char *>(Ptr), StringLen);
81   Ptr += StringLen;
82   return Return;
83 }
84 
85 static int64_t readLEB128(const uint8_t *&Ptr) {
86   unsigned Count;
87   uint64_t Result = decodeSLEB128(Ptr, &Count);
88   Ptr += Count;
89   return Result;
90 }
91 
92 static uint8_t readVaruint1(const uint8_t *&Ptr) {
93   int64_t result = readLEB128(Ptr);
94   assert(result <= VARUINT1_MAX && result >= 0);
95   return result;
96 }
97 
98 static int8_t readVarint7(const uint8_t *&Ptr) {
99   int64_t result = readLEB128(Ptr);
100   assert(result <= VARINT7_MAX && result >= VARINT7_MIN);
101   return result;
102 }
103 
104 static uint8_t readVaruint7(const uint8_t *&Ptr) {
105   uint64_t result = readULEB128(Ptr);
106   assert(result <= VARUINT7_MAX);
107   return result;
108 }
109 
110 static int32_t readVarint32(const uint8_t *&Ptr) {
111   int64_t result = readLEB128(Ptr);
112   assert(result <= INT32_MAX && result >= INT32_MIN);
113   return result;
114 }
115 
116 static uint32_t readVaruint32(const uint8_t *&Ptr) {
117   uint64_t result = readULEB128(Ptr);
118   assert(result <= UINT32_MAX);
119   return result;
120 }
121 
122 static int64_t readVarint64(const uint8_t *&Ptr) {
123   return readLEB128(Ptr);
124 }
125 
126 static uint8_t readOpcode(const uint8_t *&Ptr) {
127   return readUint8(Ptr);
128 }
129 
130 static Error readInitExpr(wasm::WasmInitExpr &Expr, const uint8_t *&Ptr) {
131   Expr.Opcode = readOpcode(Ptr);
132 
133   switch (Expr.Opcode) {
134   case wasm::WASM_OPCODE_I32_CONST:
135     Expr.Value.Int32 = readVarint32(Ptr);
136     break;
137   case wasm::WASM_OPCODE_I64_CONST:
138     Expr.Value.Int64 = readVarint64(Ptr);
139     break;
140   case wasm::WASM_OPCODE_F32_CONST:
141     Expr.Value.Float32 = readFloat32(Ptr);
142     break;
143   case wasm::WASM_OPCODE_F64_CONST:
144     Expr.Value.Float64 = readFloat64(Ptr);
145     break;
146   case wasm::WASM_OPCODE_GET_GLOBAL:
147     Expr.Value.Global = readULEB128(Ptr);
148     break;
149   default:
150     return make_error<GenericBinaryError>("Invalid opcode in init_expr",
151                                           object_error::parse_failed);
152   }
153 
154   uint8_t EndOpcode = readOpcode(Ptr);
155   if (EndOpcode != wasm::WASM_OPCODE_END) {
156     return make_error<GenericBinaryError>("Invalid init_expr",
157                                           object_error::parse_failed);
158   }
159   return Error::success();
160 }
161 
162 static wasm::WasmLimits readLimits(const uint8_t *&Ptr) {
163   wasm::WasmLimits Result;
164   Result.Flags = readVaruint1(Ptr);
165   Result.Initial = readVaruint32(Ptr);
166   if (Result.Flags & wasm::WASM_LIMITS_FLAG_HAS_MAX)
167     Result.Maximum = readVaruint32(Ptr);
168   return Result;
169 }
170 
171 static wasm::WasmTable readTable(const uint8_t *&Ptr) {
172   wasm::WasmTable Table;
173   Table.ElemType = readVarint7(Ptr);
174   Table.Limits = readLimits(Ptr);
175   return Table;
176 }
177 
178 static Error readSection(WasmSection &Section, const uint8_t *&Ptr,
179                          const uint8_t *Start) {
180   // TODO(sbc): Avoid reading past EOF in the case of malformed files.
181   Section.Offset = Ptr - Start;
182   Section.Type = readVaruint7(Ptr);
183   uint32_t Size = readVaruint32(Ptr);
184   if (Size == 0)
185     return make_error<StringError>("Zero length section",
186                                    object_error::parse_failed);
187   Section.Content = ArrayRef<uint8_t>(Ptr, Size);
188   Ptr += Size;
189   return Error::success();
190 }
191 
192 WasmObjectFile::WasmObjectFile(MemoryBufferRef Buffer, Error &Err)
193     : ObjectFile(Binary::ID_Wasm, Buffer) {
194   ErrorAsOutParameter ErrAsOutParam(&Err);
195   Header.Magic = getData().substr(0, 4);
196   if (Header.Magic != StringRef("\0asm", 4)) {
197     Err = make_error<StringError>("Bad magic number",
198                                   object_error::parse_failed);
199     return;
200   }
201   const uint8_t *Ptr = getPtr(4);
202   Header.Version = readUint32(Ptr);
203   if (Header.Version != wasm::WasmVersion) {
204     Err = make_error<StringError>("Bad version number",
205                                   object_error::parse_failed);
206     return;
207   }
208 
209   const uint8_t *Eof = getPtr(getData().size());
210   WasmSection Sec;
211   while (Ptr < Eof) {
212     if ((Err = readSection(Sec, Ptr, getPtr(0))))
213       return;
214     if ((Err = parseSection(Sec)))
215       return;
216 
217     Sections.push_back(Sec);
218   }
219 }
220 
221 Error WasmObjectFile::parseSection(WasmSection &Sec) {
222   const uint8_t* Start = Sec.Content.data();
223   const uint8_t* End = Start + Sec.Content.size();
224   switch (Sec.Type) {
225   case wasm::WASM_SEC_CUSTOM:
226     return parseCustomSection(Sec, Start, End);
227   case wasm::WASM_SEC_TYPE:
228     return parseTypeSection(Start, End);
229   case wasm::WASM_SEC_IMPORT:
230     return parseImportSection(Start, End);
231   case wasm::WASM_SEC_FUNCTION:
232     return parseFunctionSection(Start, End);
233   case wasm::WASM_SEC_TABLE:
234     return parseTableSection(Start, End);
235   case wasm::WASM_SEC_MEMORY:
236     return parseMemorySection(Start, End);
237   case wasm::WASM_SEC_GLOBAL:
238     return parseGlobalSection(Start, End);
239   case wasm::WASM_SEC_EXPORT:
240     return parseExportSection(Start, End);
241   case wasm::WASM_SEC_START:
242     return parseStartSection(Start, End);
243   case wasm::WASM_SEC_ELEM:
244     return parseElemSection(Start, End);
245   case wasm::WASM_SEC_CODE:
246     return parseCodeSection(Start, End);
247   case wasm::WASM_SEC_DATA:
248     return parseDataSection(Start, End);
249   default:
250     return make_error<GenericBinaryError>("Bad section type",
251                                           object_error::parse_failed);
252   }
253 }
254 
255 Error WasmObjectFile::parseNameSection(const uint8_t *Ptr, const uint8_t *End) {
256   while (Ptr < End) {
257     uint8_t Type = readVarint7(Ptr);
258     uint32_t Size = readVaruint32(Ptr);
259     switch (Type) {
260     case wasm::WASM_NAMES_FUNCTION: {
261       uint32_t Count = readVaruint32(Ptr);
262       while (Count--) {
263         uint32_t Index = readVaruint32(Ptr);
264         StringRef Name = readString(Ptr);
265         if (!Name.empty())
266           Symbols.emplace_back(Name,
267                                WasmSymbol::SymbolType::DEBUG_FUNCTION_NAME,
268                                Sections.size(), Index);
269       }
270       break;
271     }
272     // Ignore local names for now
273     case wasm::WASM_NAMES_LOCAL:
274     default:
275       Ptr += Size;
276       break;
277     }
278   }
279 
280   if (Ptr != End)
281     return make_error<GenericBinaryError>("Name section ended prematurely",
282                                           object_error::parse_failed);
283   return Error::success();
284 }
285 
286 WasmSection* WasmObjectFile::findCustomSectionByName(StringRef Name) {
287   for (WasmSection& Section : Sections) {
288     if (Section.Type == wasm::WASM_SEC_CUSTOM && Section.Name == Name)
289       return &Section;
290   }
291   return nullptr;
292 }
293 
294 WasmSection* WasmObjectFile::findSectionByType(uint32_t Type) {
295   assert(Type != wasm::WASM_SEC_CUSTOM);
296   for (WasmSection& Section : Sections) {
297     if (Section.Type == Type)
298       return &Section;
299   }
300   return nullptr;
301 }
302 
303 Error WasmObjectFile::parseRelocSection(StringRef Name, const uint8_t *Ptr,
304                                         const uint8_t *End) {
305   uint8_t SectionCode = readVarint7(Ptr);
306   WasmSection* Section = nullptr;
307   if (SectionCode == wasm::WASM_SEC_CUSTOM) {
308     StringRef Name = readString(Ptr);
309     Section = findCustomSectionByName(Name);
310   } else {
311     Section = findSectionByType(SectionCode);
312   }
313   if (!Section)
314     return make_error<GenericBinaryError>("Invalid section code",
315                                           object_error::parse_failed);
316   uint32_t RelocCount = readVaruint32(Ptr);
317   while (RelocCount--) {
318     wasm::WasmRelocation Reloc;
319     memset(&Reloc, 0, sizeof(Reloc));
320     Reloc.Type = readVaruint32(Ptr);
321     Reloc.Offset = readVaruint32(Ptr);
322     Reloc.Index = readVaruint32(Ptr);
323     switch (Reloc.Type) {
324     case wasm::R_WEBASSEMBLY_FUNCTION_INDEX_LEB:
325     case wasm::R_WEBASSEMBLY_TABLE_INDEX_SLEB:
326     case wasm::R_WEBASSEMBLY_TABLE_INDEX_I32:
327     case wasm::R_WEBASSEMBLY_TYPE_INDEX_LEB:
328       break;
329     case wasm::R_WEBASSEMBLY_GLOBAL_ADDR_LEB:
330     case wasm::R_WEBASSEMBLY_GLOBAL_ADDR_SLEB:
331     case wasm::R_WEBASSEMBLY_GLOBAL_ADDR_I32:
332       Reloc.Addend = readVarint32(Ptr);
333       break;
334     default:
335       return make_error<GenericBinaryError>("Bad relocation type",
336                                             object_error::parse_failed);
337     }
338     Section->Relocations.push_back(Reloc);
339   }
340   if (Ptr != End)
341     return make_error<GenericBinaryError>("Reloc section ended prematurely",
342                                           object_error::parse_failed);
343   return Error::success();
344 }
345 
346 Error WasmObjectFile::parseCustomSection(WasmSection &Sec,
347                                          const uint8_t *Ptr, const uint8_t *End) {
348   Sec.Name = readString(Ptr);
349   if (Sec.Name == "name") {
350     if (Error Err = parseNameSection(Ptr, End))
351       return Err;
352   } else if (Sec.Name.startswith("reloc.")) {
353     if (Error Err = parseRelocSection(Sec.Name, Ptr, End))
354       return Err;
355   }
356   return Error::success();
357 }
358 
359 Error WasmObjectFile::parseTypeSection(const uint8_t *Ptr, const uint8_t *End) {
360   uint32_t Count = readVaruint32(Ptr);
361   Signatures.reserve(Count);
362   while (Count--) {
363     wasm::WasmSignature Sig;
364     Sig.ReturnType = wasm::WASM_TYPE_NORESULT;
365     int8_t Form = readVarint7(Ptr);
366     if (Form != wasm::WASM_TYPE_FUNC) {
367       return make_error<GenericBinaryError>("Invalid signature type",
368                                             object_error::parse_failed);
369     }
370     uint32_t ParamCount = readVaruint32(Ptr);
371     Sig.ParamTypes.reserve(ParamCount);
372     while (ParamCount--) {
373       uint32_t ParamType = readVarint7(Ptr);
374       Sig.ParamTypes.push_back(ParamType);
375     }
376     uint32_t ReturnCount = readVaruint32(Ptr);
377     if (ReturnCount) {
378       if (ReturnCount != 1) {
379         return make_error<GenericBinaryError>(
380             "Multiple return types not supported", object_error::parse_failed);
381       }
382       Sig.ReturnType = readVarint7(Ptr);
383     }
384     Signatures.push_back(Sig);
385   }
386   if (Ptr != End)
387     return make_error<GenericBinaryError>("Type section ended prematurely",
388                                           object_error::parse_failed);
389   return Error::success();
390 }
391 
392 Error WasmObjectFile::parseImportSection(const uint8_t *Ptr, const uint8_t *End) {
393   uint32_t Count = readVaruint32(Ptr);
394   Imports.reserve(Count);
395   for (uint32_t i = 0; i < Count; i++) {
396     wasm::WasmImport Im;
397     Im.Module = readString(Ptr);
398     Im.Field = readString(Ptr);
399     Im.Kind = readUint8(Ptr);
400     switch (Im.Kind) {
401     case wasm::WASM_EXTERNAL_FUNCTION:
402       Im.SigIndex = readVaruint32(Ptr);
403       Symbols.emplace_back(Im.Field, WasmSymbol::SymbolType::FUNCTION_IMPORT,
404                            Sections.size(), i);
405       break;
406     case wasm::WASM_EXTERNAL_GLOBAL:
407       Im.Global.Type = readVarint7(Ptr);
408       Im.Global.Mutable = readVaruint1(Ptr);
409       Symbols.emplace_back(Im.Field, WasmSymbol::SymbolType::GLOBAL_IMPORT,
410                            Sections.size(), i);
411       break;
412     case wasm::WASM_EXTERNAL_MEMORY:
413       Im.Memory = readLimits(Ptr);
414       break;
415     case wasm::WASM_EXTERNAL_TABLE:
416       Im.Table = readTable(Ptr);
417       if (Im.Table.ElemType != wasm::WASM_TYPE_ANYFUNC) {
418         return make_error<GenericBinaryError>("Invalid table element type",
419                                               object_error::parse_failed);
420       }
421       break;
422     default:
423       return make_error<GenericBinaryError>(
424           "Unexpected import kind", object_error::parse_failed);
425     }
426     Imports.push_back(Im);
427   }
428   if (Ptr != End)
429     return make_error<GenericBinaryError>("Import section ended prematurely",
430                                           object_error::parse_failed);
431   return Error::success();
432 }
433 
434 Error WasmObjectFile::parseFunctionSection(const uint8_t *Ptr, const uint8_t *End) {
435   uint32_t Count = readVaruint32(Ptr);
436   FunctionTypes.reserve(Count);
437   while (Count--) {
438     FunctionTypes.push_back(readVaruint32(Ptr));
439   }
440   if (Ptr != End)
441     return make_error<GenericBinaryError>("Function section ended prematurely",
442                                           object_error::parse_failed);
443   return Error::success();
444 }
445 
446 Error WasmObjectFile::parseTableSection(const uint8_t *Ptr, const uint8_t *End) {
447   uint32_t Count = readVaruint32(Ptr);
448   Tables.reserve(Count);
449   while (Count--) {
450     Tables.push_back(readTable(Ptr));
451     if (Tables.back().ElemType != wasm::WASM_TYPE_ANYFUNC) {
452       return make_error<GenericBinaryError>("Invalid table element type",
453                                             object_error::parse_failed);
454     }
455   }
456   if (Ptr != End)
457     return make_error<GenericBinaryError>("Table section ended prematurely",
458                                           object_error::parse_failed);
459   return Error::success();
460 }
461 
462 Error WasmObjectFile::parseMemorySection(const uint8_t *Ptr, const uint8_t *End) {
463   uint32_t Count = readVaruint32(Ptr);
464   Memories.reserve(Count);
465   while (Count--) {
466     Memories.push_back(readLimits(Ptr));
467   }
468   if (Ptr != End)
469     return make_error<GenericBinaryError>("Memory section ended prematurely",
470                                           object_error::parse_failed);
471   return Error::success();
472 }
473 
474 Error WasmObjectFile::parseGlobalSection(const uint8_t *Ptr, const uint8_t *End) {
475   uint32_t Count = readVaruint32(Ptr);
476   Globals.reserve(Count);
477   while (Count--) {
478     wasm::WasmGlobal Global;
479     Global.Type = readVarint7(Ptr);
480     Global.Mutable = readVaruint1(Ptr);
481     if (Error Err = readInitExpr(Global.InitExpr, Ptr))
482       return Err;
483     Globals.push_back(Global);
484   }
485   if (Ptr != End)
486     return make_error<GenericBinaryError>("Global section ended prematurely",
487                                           object_error::parse_failed);
488   return Error::success();
489 }
490 
491 Error WasmObjectFile::parseExportSection(const uint8_t *Ptr, const uint8_t *End) {
492   uint32_t Count = readVaruint32(Ptr);
493   Exports.reserve(Count);
494   for (uint32_t i = 0; i < Count; i++) {
495     wasm::WasmExport Ex;
496     Ex.Name = readString(Ptr);
497     Ex.Kind = readUint8(Ptr);
498     Ex.Index = readVaruint32(Ptr);
499     Exports.push_back(Ex);
500     switch (Ex.Kind) {
501     case wasm::WASM_EXTERNAL_FUNCTION:
502       Symbols.emplace_back(Ex.Name, WasmSymbol::SymbolType::FUNCTION_EXPORT,
503                            Sections.size(), i);
504       break;
505     case wasm::WASM_EXTERNAL_GLOBAL:
506       Symbols.emplace_back(Ex.Name, WasmSymbol::SymbolType::GLOBAL_EXPORT,
507                            Sections.size(), i);
508       break;
509     case wasm::WASM_EXTERNAL_MEMORY:
510     case wasm::WASM_EXTERNAL_TABLE:
511       break;
512     default:
513       return make_error<GenericBinaryError>(
514           "Unexpected export kind", object_error::parse_failed);
515     }
516   }
517   if (Ptr != End)
518     return make_error<GenericBinaryError>("Export section ended prematurely",
519                                           object_error::parse_failed);
520   return Error::success();
521 }
522 
523 Error WasmObjectFile::parseStartSection(const uint8_t *Ptr, const uint8_t *End) {
524   StartFunction = readVaruint32(Ptr);
525   if (StartFunction >= FunctionTypes.size())
526     return make_error<GenericBinaryError>("Invalid start function",
527                                           object_error::parse_failed);
528   return Error::success();
529 }
530 
531 Error WasmObjectFile::parseCodeSection(const uint8_t *Ptr, const uint8_t *End) {
532   uint32_t FunctionCount = readVaruint32(Ptr);
533   if (FunctionCount != FunctionTypes.size()) {
534     return make_error<GenericBinaryError>("Invalid function count",
535                                           object_error::parse_failed);
536   }
537 
538   CodeSection = ArrayRef<uint8_t>(Ptr, End - Ptr);
539 
540   while (FunctionCount--) {
541     wasm::WasmFunction Function;
542     uint32_t FunctionSize = readVaruint32(Ptr);
543     const uint8_t *FunctionEnd = Ptr + FunctionSize;
544 
545     uint32_t NumLocalDecls = readVaruint32(Ptr);
546     Function.Locals.reserve(NumLocalDecls);
547     while (NumLocalDecls--) {
548       wasm::WasmLocalDecl Decl;
549       Decl.Count = readVaruint32(Ptr);
550       Decl.Type = readVarint7(Ptr);
551       Function.Locals.push_back(Decl);
552     }
553 
554     uint32_t BodySize = FunctionEnd - Ptr;
555     Function.Body = ArrayRef<uint8_t>(Ptr, BodySize);
556     Ptr += BodySize;
557     assert(Ptr == FunctionEnd);
558     Functions.push_back(Function);
559   }
560   if (Ptr != End)
561     return make_error<GenericBinaryError>("Code section ended prematurely",
562                                           object_error::parse_failed);
563   return Error::success();
564 }
565 
566 Error WasmObjectFile::parseElemSection(const uint8_t *Ptr, const uint8_t *End) {
567   uint32_t Count = readVaruint32(Ptr);
568   ElemSegments.reserve(Count);
569   while (Count--) {
570     wasm::WasmElemSegment Segment;
571     Segment.TableIndex = readVaruint32(Ptr);
572     if (Segment.TableIndex != 0) {
573       return make_error<GenericBinaryError>("Invalid TableIndex",
574                                             object_error::parse_failed);
575     }
576     if (Error Err = readInitExpr(Segment.Offset, Ptr))
577       return Err;
578     uint32_t NumElems = readVaruint32(Ptr);
579     while (NumElems--) {
580       Segment.Functions.push_back(readVaruint32(Ptr));
581     }
582     ElemSegments.push_back(Segment);
583   }
584   if (Ptr != End)
585     return make_error<GenericBinaryError>("Elem section ended prematurely",
586                                           object_error::parse_failed);
587   return Error::success();
588 }
589 
590 Error WasmObjectFile::parseDataSection(const uint8_t *Ptr, const uint8_t *End) {
591   uint32_t Count = readVaruint32(Ptr);
592   DataSegments.reserve(Count);
593   while (Count--) {
594     wasm::WasmDataSegment Segment;
595     Segment.Index = readVaruint32(Ptr);
596     if (Error Err = readInitExpr(Segment.Offset, Ptr))
597       return Err;
598     uint32_t Size = readVaruint32(Ptr);
599     Segment.Content = ArrayRef<uint8_t>(Ptr, Size);
600     Ptr += Size;
601     DataSegments.push_back(Segment);
602   }
603   if (Ptr != End)
604     return make_error<GenericBinaryError>("Data section ended prematurely",
605                                           object_error::parse_failed);
606   return Error::success();
607 }
608 
609 const uint8_t *WasmObjectFile::getPtr(size_t Offset) const {
610   return reinterpret_cast<const uint8_t *>(getData().substr(Offset, 1).data());
611 }
612 
613 const wasm::WasmObjectHeader &WasmObjectFile::getHeader() const {
614   return Header;
615 }
616 
617 void WasmObjectFile::moveSymbolNext(DataRefImpl &Symb) const { Symb.d.a++; }
618 
619 uint32_t WasmObjectFile::getSymbolFlags(DataRefImpl Symb) const {
620   uint32_t Result = SymbolRef::SF_None;
621   const WasmSymbol &Sym = getWasmSymbol(Symb);
622 
623   switch (Sym.Type) {
624   case WasmSymbol::SymbolType::FUNCTION_IMPORT:
625     Result |= SymbolRef::SF_Undefined | SymbolRef::SF_Executable;
626     break;
627   case WasmSymbol::SymbolType::FUNCTION_EXPORT:
628     Result |= SymbolRef::SF_Global | SymbolRef::SF_Executable;
629     break;
630   case WasmSymbol::SymbolType::DEBUG_FUNCTION_NAME:
631     Result |= SymbolRef::SF_Executable;
632     break;
633   case WasmSymbol::SymbolType::GLOBAL_IMPORT:
634     Result |= SymbolRef::SF_Undefined;
635     break;
636   case WasmSymbol::SymbolType::GLOBAL_EXPORT:
637     Result |= SymbolRef::SF_Global;
638     break;
639   }
640 
641   return Result;
642 }
643 
644 basic_symbol_iterator WasmObjectFile::symbol_begin() const {
645   DataRefImpl Ref;
646   Ref.d.a = 0;
647   return BasicSymbolRef(Ref, this);
648 }
649 
650 basic_symbol_iterator WasmObjectFile::symbol_end() const {
651   DataRefImpl Ref;
652   Ref.d.a = Symbols.size();
653   return BasicSymbolRef(Ref, this);
654 }
655 
656 const WasmSymbol &WasmObjectFile::getWasmSymbol(const DataRefImpl &Symb) const {
657   return Symbols[Symb.d.a];
658 }
659 
660 const WasmSymbol &WasmObjectFile::getWasmSymbol(const SymbolRef &Symb) const {
661   return getWasmSymbol(Symb.getRawDataRefImpl());
662 }
663 
664 Expected<StringRef> WasmObjectFile::getSymbolName(DataRefImpl Symb) const {
665   const WasmSymbol &Sym = getWasmSymbol(Symb);
666   return Sym.Name;
667 }
668 
669 Expected<uint64_t> WasmObjectFile::getSymbolAddress(DataRefImpl Symb) const {
670   return getSymbolValue(Symb);
671 }
672 
673 uint64_t WasmObjectFile::getSymbolValueImpl(DataRefImpl Symb) const {
674   const WasmSymbol &Sym = getWasmSymbol(Symb);
675   return Sym.ElementIndex;
676 }
677 
678 uint32_t WasmObjectFile::getSymbolAlignment(DataRefImpl Symb) const {
679   llvm_unreachable("not yet implemented");
680   return 0;
681 }
682 
683 uint64_t WasmObjectFile::getCommonSymbolSizeImpl(DataRefImpl Symb) const {
684   llvm_unreachable("not yet implemented");
685   return 0;
686 }
687 
688 Expected<SymbolRef::Type>
689 WasmObjectFile::getSymbolType(DataRefImpl Symb) const {
690   const WasmSymbol &Sym = getWasmSymbol(Symb);
691 
692   switch (Sym.Type) {
693   case WasmSymbol::SymbolType::FUNCTION_IMPORT:
694   case WasmSymbol::SymbolType::FUNCTION_EXPORT:
695   case WasmSymbol::SymbolType::DEBUG_FUNCTION_NAME:
696     return SymbolRef::ST_Function;
697   case WasmSymbol::SymbolType::GLOBAL_IMPORT:
698   case WasmSymbol::SymbolType::GLOBAL_EXPORT:
699     return SymbolRef::ST_Data;
700   }
701 
702   llvm_unreachable("Unknown WasmSymbol::SymbolType");
703   return SymbolRef::ST_Other;
704 }
705 
706 Expected<section_iterator>
707 WasmObjectFile::getSymbolSection(DataRefImpl Symb) const {
708   DataRefImpl Ref;
709   Ref.d.a = getWasmSymbol(Symb).Section;
710   return section_iterator(SectionRef(Ref, this));
711 }
712 
713 void WasmObjectFile::moveSectionNext(DataRefImpl &Sec) const { Sec.d.a++; }
714 
715 std::error_code WasmObjectFile::getSectionName(DataRefImpl Sec,
716                                                StringRef &Res) const {
717   const WasmSection &S = Sections[Sec.d.a];
718 #define ECase(X)                                                               \
719   case wasm::WASM_SEC_##X:                                                     \
720     Res = #X;                                                                  \
721     break
722   switch (S.Type) {
723     ECase(TYPE);
724     ECase(IMPORT);
725     ECase(FUNCTION);
726     ECase(TABLE);
727     ECase(MEMORY);
728     ECase(GLOBAL);
729     ECase(EXPORT);
730     ECase(START);
731     ECase(ELEM);
732     ECase(CODE);
733     ECase(DATA);
734   case wasm::WASM_SEC_CUSTOM:
735     Res = S.Name;
736     break;
737   default:
738     return object_error::invalid_section_index;
739   }
740 #undef ECase
741   return std::error_code();
742 }
743 
744 uint64_t WasmObjectFile::getSectionAddress(DataRefImpl Sec) const { return 0; }
745 
746 uint64_t WasmObjectFile::getSectionSize(DataRefImpl Sec) const {
747   const WasmSection &S = Sections[Sec.d.a];
748   return S.Content.size();
749 }
750 
751 std::error_code WasmObjectFile::getSectionContents(DataRefImpl Sec,
752                                                    StringRef &Res) const {
753   const WasmSection &S = Sections[Sec.d.a];
754   // This will never fail since wasm sections can never be empty (user-sections
755   // must have a name and non-user sections each have a defined structure).
756   Res = StringRef(reinterpret_cast<const char *>(S.Content.data()),
757                   S.Content.size());
758   return std::error_code();
759 }
760 
761 uint64_t WasmObjectFile::getSectionAlignment(DataRefImpl Sec) const {
762   return 1;
763 }
764 
765 bool WasmObjectFile::isSectionCompressed(DataRefImpl Sec) const {
766   return false;
767 }
768 
769 bool WasmObjectFile::isSectionText(DataRefImpl Sec) const {
770   return getWasmSection(Sec).Type == wasm::WASM_SEC_CODE;
771 }
772 
773 bool WasmObjectFile::isSectionData(DataRefImpl Sec) const {
774   return getWasmSection(Sec).Type == wasm::WASM_SEC_DATA;
775 }
776 
777 bool WasmObjectFile::isSectionBSS(DataRefImpl Sec) const { return false; }
778 
779 bool WasmObjectFile::isSectionVirtual(DataRefImpl Sec) const { return false; }
780 
781 bool WasmObjectFile::isSectionBitcode(DataRefImpl Sec) const { return false; }
782 
783 relocation_iterator WasmObjectFile::section_rel_begin(DataRefImpl Ref) const {
784   DataRefImpl RelocRef;
785   RelocRef.d.a = Ref.d.a;
786   RelocRef.d.b = 0;
787   return relocation_iterator(RelocationRef(RelocRef, this));
788 }
789 
790 relocation_iterator WasmObjectFile::section_rel_end(DataRefImpl Ref) const {
791   const WasmSection &Sec = getWasmSection(Ref);
792   DataRefImpl RelocRef;
793   RelocRef.d.a = Ref.d.a;
794   RelocRef.d.b = Sec.Relocations.size();
795   return relocation_iterator(RelocationRef(RelocRef, this));
796 }
797 
798 void WasmObjectFile::moveRelocationNext(DataRefImpl &Rel) const {
799   Rel.d.b++;
800 }
801 
802 uint64_t WasmObjectFile::getRelocationOffset(DataRefImpl Ref) const {
803   const wasm::WasmRelocation &Rel = getWasmRelocation(Ref);
804   return Rel.Offset;
805 }
806 
807 symbol_iterator WasmObjectFile::getRelocationSymbol(DataRefImpl Rel) const {
808   llvm_unreachable("not yet implemented");
809   SymbolRef Ref;
810   return symbol_iterator(Ref);
811 }
812 
813 uint64_t WasmObjectFile::getRelocationType(DataRefImpl Ref) const {
814   const wasm::WasmRelocation &Rel = getWasmRelocation(Ref);
815   return Rel.Type;
816 }
817 
818 void WasmObjectFile::getRelocationTypeName(
819     DataRefImpl Ref, SmallVectorImpl<char> &Result) const {
820   const wasm::WasmRelocation& Rel = getWasmRelocation(Ref);
821   StringRef Res = "Unknown";
822 
823 #define WASM_RELOC(name, value)  \
824   case wasm::name:              \
825     Res = #name;               \
826     break;
827 
828   switch (Rel.Type) {
829 #include "llvm/Support/WasmRelocs/WebAssembly.def"
830   }
831 
832 #undef WASM_RELOC
833 
834   Result.append(Res.begin(), Res.end());
835 }
836 
837 section_iterator WasmObjectFile::section_begin() const {
838   DataRefImpl Ref;
839   Ref.d.a = 0;
840   return section_iterator(SectionRef(Ref, this));
841 }
842 
843 section_iterator WasmObjectFile::section_end() const {
844   DataRefImpl Ref;
845   Ref.d.a = Sections.size();
846   return section_iterator(SectionRef(Ref, this));
847 }
848 
849 uint8_t WasmObjectFile::getBytesInAddress() const { return 4; }
850 
851 StringRef WasmObjectFile::getFileFormatName() const { return "WASM"; }
852 
853 unsigned WasmObjectFile::getArch() const { return Triple::wasm32; }
854 
855 SubtargetFeatures WasmObjectFile::getFeatures() const {
856   return SubtargetFeatures();
857 }
858 
859 bool WasmObjectFile::isRelocatableObject() const { return false; }
860 
861 const WasmSection &WasmObjectFile::getWasmSection(DataRefImpl Ref) const {
862   assert(Ref.d.a < Sections.size());
863   return Sections[Ref.d.a];
864 }
865 
866 const WasmSection &
867 WasmObjectFile::getWasmSection(const SectionRef &Section) const {
868   return getWasmSection(Section.getRawDataRefImpl());
869 }
870 
871 const wasm::WasmRelocation &
872 WasmObjectFile::getWasmRelocation(const RelocationRef &Ref) const {
873   return getWasmRelocation(Ref.getRawDataRefImpl());
874 }
875 
876 const wasm::WasmRelocation &
877 WasmObjectFile::getWasmRelocation(DataRefImpl Ref) const {
878   assert(Ref.d.a < Sections.size());
879   const WasmSection& Sec = Sections[Ref.d.a];
880   assert(Ref.d.b < Sec.Relocations.size());
881   return Sec.Relocations[Ref.d.b];
882 }
883