10b57cec5SDimitry Andric //===- lib/MC/WasmObjectWriter.cpp - Wasm File Writer ---------------------===// 20b57cec5SDimitry Andric // 30b57cec5SDimitry Andric // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 40b57cec5SDimitry Andric // See https://llvm.org/LICENSE.txt for license information. 50b57cec5SDimitry Andric // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 60b57cec5SDimitry Andric // 70b57cec5SDimitry Andric //===----------------------------------------------------------------------===// 80b57cec5SDimitry Andric // 90b57cec5SDimitry Andric // This file implements Wasm object file writer information. 100b57cec5SDimitry Andric // 110b57cec5SDimitry Andric //===----------------------------------------------------------------------===// 120b57cec5SDimitry Andric 130b57cec5SDimitry Andric #include "llvm/ADT/STLExtras.h" 140b57cec5SDimitry Andric #include "llvm/BinaryFormat/Wasm.h" 15e8d8bef9SDimitry Andric #include "llvm/BinaryFormat/WasmTraits.h" 160b57cec5SDimitry Andric #include "llvm/Config/llvm-config.h" 170b57cec5SDimitry Andric #include "llvm/MC/MCAsmBackend.h" 180b57cec5SDimitry Andric #include "llvm/MC/MCAsmLayout.h" 190b57cec5SDimitry Andric #include "llvm/MC/MCAssembler.h" 200b57cec5SDimitry Andric #include "llvm/MC/MCContext.h" 210b57cec5SDimitry Andric #include "llvm/MC/MCExpr.h" 220b57cec5SDimitry Andric #include "llvm/MC/MCFixupKindInfo.h" 230b57cec5SDimitry Andric #include "llvm/MC/MCObjectWriter.h" 240b57cec5SDimitry Andric #include "llvm/MC/MCSectionWasm.h" 250b57cec5SDimitry Andric #include "llvm/MC/MCSymbolWasm.h" 260b57cec5SDimitry Andric #include "llvm/MC/MCValue.h" 270b57cec5SDimitry Andric #include "llvm/MC/MCWasmObjectWriter.h" 280b57cec5SDimitry Andric #include "llvm/Support/Casting.h" 290b57cec5SDimitry Andric #include "llvm/Support/Debug.h" 305ffd83dbSDimitry Andric #include "llvm/Support/EndianStream.h" 310b57cec5SDimitry Andric #include "llvm/Support/ErrorHandling.h" 320b57cec5SDimitry Andric #include "llvm/Support/LEB128.h" 330b57cec5SDimitry Andric #include <vector> 340b57cec5SDimitry Andric 350b57cec5SDimitry Andric using namespace llvm; 360b57cec5SDimitry Andric 370b57cec5SDimitry Andric #define DEBUG_TYPE "mc" 380b57cec5SDimitry Andric 390b57cec5SDimitry Andric namespace { 400b57cec5SDimitry Andric 41e8d8bef9SDimitry Andric // When we create the indirect function table we start at 1, so that there is 42e8d8bef9SDimitry Andric // and empty slot at 0 and therefore calling a null function pointer will trap. 430b57cec5SDimitry Andric static const uint32_t InitialTableOffset = 1; 440b57cec5SDimitry Andric 450b57cec5SDimitry Andric // For patching purposes, we need to remember where each section starts, both 460b57cec5SDimitry Andric // for patching up the section size field, and for patching up references to 470b57cec5SDimitry Andric // locations within the section. 480b57cec5SDimitry Andric struct SectionBookkeeping { 490b57cec5SDimitry Andric // Where the size of the section is written. 500b57cec5SDimitry Andric uint64_t SizeOffset; 510b57cec5SDimitry Andric // Where the section header ends (without custom section name). 520b57cec5SDimitry Andric uint64_t PayloadOffset; 530b57cec5SDimitry Andric // Where the contents of the section starts. 540b57cec5SDimitry Andric uint64_t ContentsOffset; 550b57cec5SDimitry Andric uint32_t Index; 560b57cec5SDimitry Andric }; 570b57cec5SDimitry Andric 580b57cec5SDimitry Andric // A wasm data segment. A wasm binary contains only a single data section 590b57cec5SDimitry Andric // but that can contain many segments, each with their own virtual location 600b57cec5SDimitry Andric // in memory. Each MCSection data created by llvm is modeled as its own 610b57cec5SDimitry Andric // wasm data segment. 620b57cec5SDimitry Andric struct WasmDataSegment { 630b57cec5SDimitry Andric MCSectionWasm *Section; 640b57cec5SDimitry Andric StringRef Name; 650b57cec5SDimitry Andric uint32_t InitFlags; 665ffd83dbSDimitry Andric uint64_t Offset; 670b57cec5SDimitry Andric uint32_t Alignment; 68fe6060f1SDimitry Andric uint32_t LinkingFlags; 690b57cec5SDimitry Andric SmallVector<char, 4> Data; 700b57cec5SDimitry Andric }; 710b57cec5SDimitry Andric 720b57cec5SDimitry Andric // A wasm function to be written into the function section. 730b57cec5SDimitry Andric struct WasmFunction { 740b57cec5SDimitry Andric uint32_t SigIndex; 75bdd1243dSDimitry Andric MCSection *Section; 760b57cec5SDimitry Andric }; 770b57cec5SDimitry Andric 780b57cec5SDimitry Andric // A wasm global to be written into the global section. 790b57cec5SDimitry Andric struct WasmGlobal { 800b57cec5SDimitry Andric wasm::WasmGlobalType Type; 810b57cec5SDimitry Andric uint64_t InitialValue; 820b57cec5SDimitry Andric }; 830b57cec5SDimitry Andric 840b57cec5SDimitry Andric // Information about a single item which is part of a COMDAT. For each data 850b57cec5SDimitry Andric // segment or function which is in the COMDAT, there is a corresponding 860b57cec5SDimitry Andric // WasmComdatEntry. 870b57cec5SDimitry Andric struct WasmComdatEntry { 880b57cec5SDimitry Andric unsigned Kind; 890b57cec5SDimitry Andric uint32_t Index; 900b57cec5SDimitry Andric }; 910b57cec5SDimitry Andric 920b57cec5SDimitry Andric // Information about a single relocation. 930b57cec5SDimitry Andric struct WasmRelocationEntry { 940b57cec5SDimitry Andric uint64_t Offset; // Where is the relocation. 950b57cec5SDimitry Andric const MCSymbolWasm *Symbol; // The symbol to relocate with. 960b57cec5SDimitry Andric int64_t Addend; // A value to add to the symbol. 970b57cec5SDimitry Andric unsigned Type; // The type of the relocation. 980b57cec5SDimitry Andric const MCSectionWasm *FixupSection; // The section the relocation is targeting. 990b57cec5SDimitry Andric 1000b57cec5SDimitry Andric WasmRelocationEntry(uint64_t Offset, const MCSymbolWasm *Symbol, 1010b57cec5SDimitry Andric int64_t Addend, unsigned Type, 1020b57cec5SDimitry Andric const MCSectionWasm *FixupSection) 1030b57cec5SDimitry Andric : Offset(Offset), Symbol(Symbol), Addend(Addend), Type(Type), 1040b57cec5SDimitry Andric FixupSection(FixupSection) {} 1050b57cec5SDimitry Andric 1060b57cec5SDimitry Andric bool hasAddend() const { return wasm::relocTypeHasAddend(Type); } 1070b57cec5SDimitry Andric 1080b57cec5SDimitry Andric void print(raw_ostream &Out) const { 1090b57cec5SDimitry Andric Out << wasm::relocTypetoString(Type) << " Off=" << Offset 1100b57cec5SDimitry Andric << ", Sym=" << *Symbol << ", Addend=" << Addend 1115ffd83dbSDimitry Andric << ", FixupSection=" << FixupSection->getName(); 1120b57cec5SDimitry Andric } 1130b57cec5SDimitry Andric 1140b57cec5SDimitry Andric #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP) 1150b57cec5SDimitry Andric LLVM_DUMP_METHOD void dump() const { print(dbgs()); } 1160b57cec5SDimitry Andric #endif 1170b57cec5SDimitry Andric }; 1180b57cec5SDimitry Andric 1190b57cec5SDimitry Andric static const uint32_t InvalidIndex = -1; 1200b57cec5SDimitry Andric 1210b57cec5SDimitry Andric struct WasmCustomSection { 1220b57cec5SDimitry Andric 1230b57cec5SDimitry Andric StringRef Name; 1240b57cec5SDimitry Andric MCSectionWasm *Section; 1250b57cec5SDimitry Andric 12681ad6265SDimitry Andric uint32_t OutputContentsOffset = 0; 12781ad6265SDimitry Andric uint32_t OutputIndex = InvalidIndex; 1280b57cec5SDimitry Andric 1290b57cec5SDimitry Andric WasmCustomSection(StringRef Name, MCSectionWasm *Section) 13081ad6265SDimitry Andric : Name(Name), Section(Section) {} 1310b57cec5SDimitry Andric }; 1320b57cec5SDimitry Andric 1330b57cec5SDimitry Andric #if !defined(NDEBUG) 1340b57cec5SDimitry Andric raw_ostream &operator<<(raw_ostream &OS, const WasmRelocationEntry &Rel) { 1350b57cec5SDimitry Andric Rel.print(OS); 1360b57cec5SDimitry Andric return OS; 1370b57cec5SDimitry Andric } 1380b57cec5SDimitry Andric #endif 1390b57cec5SDimitry Andric 140fb03ea46SDimitry Andric // Write Value as an (unsigned) LEB value at offset Offset in Stream, padded 1410b57cec5SDimitry Andric // to allow patching. 142fb03ea46SDimitry Andric template <typename T, int W> 143fb03ea46SDimitry Andric void writePatchableULEB(raw_pwrite_stream &Stream, T Value, uint64_t Offset) { 1445ffd83dbSDimitry Andric uint8_t Buffer[W]; 145fb03ea46SDimitry Andric unsigned SizeLen = encodeULEB128(Value, Buffer, W); 1465ffd83dbSDimitry Andric assert(SizeLen == W); 1470b57cec5SDimitry Andric Stream.pwrite((char *)Buffer, SizeLen, Offset); 1480b57cec5SDimitry Andric } 1490b57cec5SDimitry Andric 150fb03ea46SDimitry Andric // Write Value as an signed LEB value at offset Offset in Stream, padded 1510b57cec5SDimitry Andric // to allow patching. 152fb03ea46SDimitry Andric template <typename T, int W> 153fb03ea46SDimitry Andric void writePatchableSLEB(raw_pwrite_stream &Stream, T Value, uint64_t Offset) { 1545ffd83dbSDimitry Andric uint8_t Buffer[W]; 155fb03ea46SDimitry Andric unsigned SizeLen = encodeSLEB128(Value, Buffer, W); 1565ffd83dbSDimitry Andric assert(SizeLen == W); 1570b57cec5SDimitry Andric Stream.pwrite((char *)Buffer, SizeLen, Offset); 1580b57cec5SDimitry Andric } 1590b57cec5SDimitry Andric 160fb03ea46SDimitry Andric static void writePatchableU32(raw_pwrite_stream &Stream, uint32_t Value, 161fb03ea46SDimitry Andric uint64_t Offset) { 162fb03ea46SDimitry Andric writePatchableULEB<uint32_t, 5>(Stream, Value, Offset); 163fb03ea46SDimitry Andric } 164fb03ea46SDimitry Andric 165fb03ea46SDimitry Andric static void writePatchableS32(raw_pwrite_stream &Stream, int32_t Value, 166fb03ea46SDimitry Andric uint64_t Offset) { 167fb03ea46SDimitry Andric writePatchableSLEB<int32_t, 5>(Stream, Value, Offset); 168fb03ea46SDimitry Andric } 169fb03ea46SDimitry Andric 170fb03ea46SDimitry Andric static void writePatchableU64(raw_pwrite_stream &Stream, uint64_t Value, 171fb03ea46SDimitry Andric uint64_t Offset) { 172fb03ea46SDimitry Andric writePatchableSLEB<uint64_t, 10>(Stream, Value, Offset); 173fb03ea46SDimitry Andric } 174fb03ea46SDimitry Andric 175fb03ea46SDimitry Andric static void writePatchableS64(raw_pwrite_stream &Stream, int64_t Value, 176fb03ea46SDimitry Andric uint64_t Offset) { 177fb03ea46SDimitry Andric writePatchableSLEB<int64_t, 10>(Stream, Value, Offset); 178fb03ea46SDimitry Andric } 179fb03ea46SDimitry Andric 180fb03ea46SDimitry Andric // Write Value as a plain integer value at offset Offset in Stream. 181fb03ea46SDimitry Andric static void patchI32(raw_pwrite_stream &Stream, uint32_t Value, 182fb03ea46SDimitry Andric uint64_t Offset) { 1830b57cec5SDimitry Andric uint8_t Buffer[4]; 184fb03ea46SDimitry Andric support::endian::write32le(Buffer, Value); 1850b57cec5SDimitry Andric Stream.pwrite((char *)Buffer, sizeof(Buffer), Offset); 1860b57cec5SDimitry Andric } 1870b57cec5SDimitry Andric 188fb03ea46SDimitry Andric static void patchI64(raw_pwrite_stream &Stream, uint64_t Value, 189fb03ea46SDimitry Andric uint64_t Offset) { 1905ffd83dbSDimitry Andric uint8_t Buffer[8]; 191fb03ea46SDimitry Andric support::endian::write64le(Buffer, Value); 1925ffd83dbSDimitry Andric Stream.pwrite((char *)Buffer, sizeof(Buffer), Offset); 1935ffd83dbSDimitry Andric } 1945ffd83dbSDimitry Andric 195e8d8bef9SDimitry Andric bool isDwoSection(const MCSection &Sec) { 1965f757f3fSDimitry Andric return Sec.getName().ends_with(".dwo"); 197e8d8bef9SDimitry Andric } 198e8d8bef9SDimitry Andric 1990b57cec5SDimitry Andric class WasmObjectWriter : public MCObjectWriter { 20006c3fb27SDimitry Andric support::endian::Writer *W = nullptr; 2010b57cec5SDimitry Andric 2020b57cec5SDimitry Andric /// The target specific Wasm writer instance. 2030b57cec5SDimitry Andric std::unique_ptr<MCWasmObjectTargetWriter> TargetObjectWriter; 2040b57cec5SDimitry Andric 2050b57cec5SDimitry Andric // Relocations for fixing up references in the code section. 2060b57cec5SDimitry Andric std::vector<WasmRelocationEntry> CodeRelocations; 2070b57cec5SDimitry Andric // Relocations for fixing up references in the data section. 2080b57cec5SDimitry Andric std::vector<WasmRelocationEntry> DataRelocations; 2090b57cec5SDimitry Andric 2100b57cec5SDimitry Andric // Index values to use for fixing up call_indirect type indices. 2110b57cec5SDimitry Andric // Maps function symbols to the index of the type of the function 2120b57cec5SDimitry Andric DenseMap<const MCSymbolWasm *, uint32_t> TypeIndices; 2130b57cec5SDimitry Andric // Maps function symbols to the table element index space. Used 2140b57cec5SDimitry Andric // for TABLE_INDEX relocation types (i.e. address taken functions). 2150b57cec5SDimitry Andric DenseMap<const MCSymbolWasm *, uint32_t> TableIndices; 216e8d8bef9SDimitry Andric // Maps function/global/table symbols to the 217fe6060f1SDimitry Andric // function/global/table/tag/section index space. 2180b57cec5SDimitry Andric DenseMap<const MCSymbolWasm *, uint32_t> WasmIndices; 2190b57cec5SDimitry Andric DenseMap<const MCSymbolWasm *, uint32_t> GOTIndices; 2200b57cec5SDimitry Andric // Maps data symbols to the Wasm segment and offset/size with the segment. 2210b57cec5SDimitry Andric DenseMap<const MCSymbolWasm *, wasm::WasmDataReference> DataLocations; 2220b57cec5SDimitry Andric 2230b57cec5SDimitry Andric // Stores output data (index, relocations, content offset) for custom 2240b57cec5SDimitry Andric // section. 2250b57cec5SDimitry Andric std::vector<WasmCustomSection> CustomSections; 2260b57cec5SDimitry Andric std::unique_ptr<WasmCustomSection> ProducersSection; 2270b57cec5SDimitry Andric std::unique_ptr<WasmCustomSection> TargetFeaturesSection; 2280b57cec5SDimitry Andric // Relocations for fixing up references in the custom sections. 2290b57cec5SDimitry Andric DenseMap<const MCSectionWasm *, std::vector<WasmRelocationEntry>> 2300b57cec5SDimitry Andric CustomSectionsRelocations; 2310b57cec5SDimitry Andric 2320b57cec5SDimitry Andric // Map from section to defining function symbol. 2330b57cec5SDimitry Andric DenseMap<const MCSection *, const MCSymbol *> SectionFunctions; 2340b57cec5SDimitry Andric 235e8d8bef9SDimitry Andric DenseMap<wasm::WasmSignature, uint32_t> SignatureIndices; 236e8d8bef9SDimitry Andric SmallVector<wasm::WasmSignature, 4> Signatures; 2370b57cec5SDimitry Andric SmallVector<WasmDataSegment, 4> DataSegments; 2380b57cec5SDimitry Andric unsigned NumFunctionImports = 0; 2390b57cec5SDimitry Andric unsigned NumGlobalImports = 0; 240e8d8bef9SDimitry Andric unsigned NumTableImports = 0; 241fe6060f1SDimitry Andric unsigned NumTagImports = 0; 2420b57cec5SDimitry Andric uint32_t SectionCount = 0; 2430b57cec5SDimitry Andric 244e8d8bef9SDimitry Andric enum class DwoMode { 245e8d8bef9SDimitry Andric AllSections, 246e8d8bef9SDimitry Andric NonDwoOnly, 247e8d8bef9SDimitry Andric DwoOnly, 248e8d8bef9SDimitry Andric }; 249e8d8bef9SDimitry Andric bool IsSplitDwarf = false; 250e8d8bef9SDimitry Andric raw_pwrite_stream *OS = nullptr; 251e8d8bef9SDimitry Andric raw_pwrite_stream *DwoOS = nullptr; 252e8d8bef9SDimitry Andric 253e8d8bef9SDimitry Andric // TargetObjectWriter wranppers. 2540b57cec5SDimitry Andric bool is64Bit() const { return TargetObjectWriter->is64Bit(); } 2558bcb0991SDimitry Andric bool isEmscripten() const { return TargetObjectWriter->isEmscripten(); } 2560b57cec5SDimitry Andric 2570b57cec5SDimitry Andric void startSection(SectionBookkeeping &Section, unsigned SectionId); 2580b57cec5SDimitry Andric void startCustomSection(SectionBookkeeping &Section, StringRef Name); 2590b57cec5SDimitry Andric void endSection(SectionBookkeeping &Section); 2600b57cec5SDimitry Andric 2610b57cec5SDimitry Andric public: 2620b57cec5SDimitry Andric WasmObjectWriter(std::unique_ptr<MCWasmObjectTargetWriter> MOTW, 263e8d8bef9SDimitry Andric raw_pwrite_stream &OS_) 264e8d8bef9SDimitry Andric : TargetObjectWriter(std::move(MOTW)), OS(&OS_) {} 265e8d8bef9SDimitry Andric 266e8d8bef9SDimitry Andric WasmObjectWriter(std::unique_ptr<MCWasmObjectTargetWriter> MOTW, 267e8d8bef9SDimitry Andric raw_pwrite_stream &OS_, raw_pwrite_stream &DwoOS_) 268e8d8bef9SDimitry Andric : TargetObjectWriter(std::move(MOTW)), IsSplitDwarf(true), OS(&OS_), 269e8d8bef9SDimitry Andric DwoOS(&DwoOS_) {} 2700b57cec5SDimitry Andric 2710b57cec5SDimitry Andric private: 2720b57cec5SDimitry Andric void reset() override { 2730b57cec5SDimitry Andric CodeRelocations.clear(); 2740b57cec5SDimitry Andric DataRelocations.clear(); 2750b57cec5SDimitry Andric TypeIndices.clear(); 2760b57cec5SDimitry Andric WasmIndices.clear(); 2770b57cec5SDimitry Andric GOTIndices.clear(); 2780b57cec5SDimitry Andric TableIndices.clear(); 2790b57cec5SDimitry Andric DataLocations.clear(); 2800b57cec5SDimitry Andric CustomSections.clear(); 2810b57cec5SDimitry Andric ProducersSection.reset(); 2820b57cec5SDimitry Andric TargetFeaturesSection.reset(); 2830b57cec5SDimitry Andric CustomSectionsRelocations.clear(); 2840b57cec5SDimitry Andric SignatureIndices.clear(); 2850b57cec5SDimitry Andric Signatures.clear(); 2860b57cec5SDimitry Andric DataSegments.clear(); 2870b57cec5SDimitry Andric SectionFunctions.clear(); 2880b57cec5SDimitry Andric NumFunctionImports = 0; 2890b57cec5SDimitry Andric NumGlobalImports = 0; 290e8d8bef9SDimitry Andric NumTableImports = 0; 2910b57cec5SDimitry Andric MCObjectWriter::reset(); 2920b57cec5SDimitry Andric } 2930b57cec5SDimitry Andric 2940b57cec5SDimitry Andric void writeHeader(const MCAssembler &Asm); 2950b57cec5SDimitry Andric 2960b57cec5SDimitry Andric void recordRelocation(MCAssembler &Asm, const MCAsmLayout &Layout, 2970b57cec5SDimitry Andric const MCFragment *Fragment, const MCFixup &Fixup, 2980b57cec5SDimitry Andric MCValue Target, uint64_t &FixedValue) override; 2990b57cec5SDimitry Andric 3000b57cec5SDimitry Andric void executePostLayoutBinding(MCAssembler &Asm, 3010b57cec5SDimitry Andric const MCAsmLayout &Layout) override; 302e8d8bef9SDimitry Andric void prepareImports(SmallVectorImpl<wasm::WasmImport> &Imports, 303e8d8bef9SDimitry Andric MCAssembler &Asm, const MCAsmLayout &Layout); 3040b57cec5SDimitry Andric uint64_t writeObject(MCAssembler &Asm, const MCAsmLayout &Layout) override; 3050b57cec5SDimitry Andric 306e8d8bef9SDimitry Andric uint64_t writeOneObject(MCAssembler &Asm, const MCAsmLayout &Layout, 307e8d8bef9SDimitry Andric DwoMode Mode); 308e8d8bef9SDimitry Andric 3090b57cec5SDimitry Andric void writeString(const StringRef Str) { 310e8d8bef9SDimitry Andric encodeULEB128(Str.size(), W->OS); 311e8d8bef9SDimitry Andric W->OS << Str; 3120b57cec5SDimitry Andric } 3130b57cec5SDimitry Andric 314349cc55cSDimitry Andric void writeStringWithAlignment(const StringRef Str, unsigned Alignment); 315349cc55cSDimitry Andric 3165ffd83dbSDimitry Andric void writeI32(int32_t val) { 3175ffd83dbSDimitry Andric char Buffer[4]; 3185ffd83dbSDimitry Andric support::endian::write32le(Buffer, val); 319e8d8bef9SDimitry Andric W->OS.write(Buffer, sizeof(Buffer)); 3205ffd83dbSDimitry Andric } 3215ffd83dbSDimitry Andric 3225ffd83dbSDimitry Andric void writeI64(int64_t val) { 3235ffd83dbSDimitry Andric char Buffer[8]; 3245ffd83dbSDimitry Andric support::endian::write64le(Buffer, val); 325e8d8bef9SDimitry Andric W->OS.write(Buffer, sizeof(Buffer)); 3265ffd83dbSDimitry Andric } 3275ffd83dbSDimitry Andric 328e8d8bef9SDimitry Andric void writeValueType(wasm::ValType Ty) { W->OS << static_cast<char>(Ty); } 3290b57cec5SDimitry Andric 330e8d8bef9SDimitry Andric void writeTypeSection(ArrayRef<wasm::WasmSignature> Signatures); 3315ffd83dbSDimitry Andric void writeImportSection(ArrayRef<wasm::WasmImport> Imports, uint64_t DataSize, 3320b57cec5SDimitry Andric uint32_t NumElements); 3330b57cec5SDimitry Andric void writeFunctionSection(ArrayRef<WasmFunction> Functions); 3340b57cec5SDimitry Andric void writeExportSection(ArrayRef<wasm::WasmExport> Exports); 335fe6060f1SDimitry Andric void writeElemSection(const MCSymbolWasm *IndirectFunctionTable, 336fe6060f1SDimitry Andric ArrayRef<uint32_t> TableElems); 3370b57cec5SDimitry Andric void writeDataCountSection(); 3385ffd83dbSDimitry Andric uint32_t writeCodeSection(const MCAssembler &Asm, const MCAsmLayout &Layout, 3390b57cec5SDimitry Andric ArrayRef<WasmFunction> Functions); 3405ffd83dbSDimitry Andric uint32_t writeDataSection(const MCAsmLayout &Layout); 341349cc55cSDimitry Andric void writeTagSection(ArrayRef<uint32_t> TagTypes); 3425ffd83dbSDimitry Andric void writeGlobalSection(ArrayRef<wasm::WasmGlobal> Globals); 343e8d8bef9SDimitry Andric void writeTableSection(ArrayRef<wasm::WasmTable> Tables); 3440b57cec5SDimitry Andric void writeRelocSection(uint32_t SectionIndex, StringRef Name, 3450b57cec5SDimitry Andric std::vector<WasmRelocationEntry> &Relocations); 3460b57cec5SDimitry Andric void writeLinkingMetaDataSection( 3470b57cec5SDimitry Andric ArrayRef<wasm::WasmSymbolInfo> SymbolInfos, 3480b57cec5SDimitry Andric ArrayRef<std::pair<uint16_t, uint32_t>> InitFuncs, 3490b57cec5SDimitry Andric const std::map<StringRef, std::vector<WasmComdatEntry>> &Comdats); 3500b57cec5SDimitry Andric void writeCustomSection(WasmCustomSection &CustomSection, 3510b57cec5SDimitry Andric const MCAssembler &Asm, const MCAsmLayout &Layout); 3520b57cec5SDimitry Andric void writeCustomRelocSections(); 3530b57cec5SDimitry Andric 3545ffd83dbSDimitry Andric uint64_t getProvisionalValue(const WasmRelocationEntry &RelEntry, 3555ffd83dbSDimitry Andric const MCAsmLayout &Layout); 3560b57cec5SDimitry Andric void applyRelocations(ArrayRef<WasmRelocationEntry> Relocations, 3575ffd83dbSDimitry Andric uint64_t ContentsOffset, const MCAsmLayout &Layout); 3580b57cec5SDimitry Andric 3590b57cec5SDimitry Andric uint32_t getRelocationIndexValue(const WasmRelocationEntry &RelEntry); 3600b57cec5SDimitry Andric uint32_t getFunctionType(const MCSymbolWasm &Symbol); 361fe6060f1SDimitry Andric uint32_t getTagType(const MCSymbolWasm &Symbol); 3620b57cec5SDimitry Andric void registerFunctionType(const MCSymbolWasm &Symbol); 363fe6060f1SDimitry Andric void registerTagType(const MCSymbolWasm &Symbol); 3640b57cec5SDimitry Andric }; 3650b57cec5SDimitry Andric 3660b57cec5SDimitry Andric } // end anonymous namespace 3670b57cec5SDimitry Andric 3680b57cec5SDimitry Andric // Write out a section header and a patchable section size field. 3690b57cec5SDimitry Andric void WasmObjectWriter::startSection(SectionBookkeeping &Section, 3700b57cec5SDimitry Andric unsigned SectionId) { 3710b57cec5SDimitry Andric LLVM_DEBUG(dbgs() << "startSection " << SectionId << "\n"); 372e8d8bef9SDimitry Andric W->OS << char(SectionId); 3730b57cec5SDimitry Andric 374e8d8bef9SDimitry Andric Section.SizeOffset = W->OS.tell(); 3750b57cec5SDimitry Andric 3760b57cec5SDimitry Andric // The section size. We don't know the size yet, so reserve enough space 3770b57cec5SDimitry Andric // for any 32-bit value; we'll patch it later. 378e8d8bef9SDimitry Andric encodeULEB128(0, W->OS, 5); 3790b57cec5SDimitry Andric 3800b57cec5SDimitry Andric // The position where the section starts, for measuring its size. 381e8d8bef9SDimitry Andric Section.ContentsOffset = W->OS.tell(); 382e8d8bef9SDimitry Andric Section.PayloadOffset = W->OS.tell(); 3830b57cec5SDimitry Andric Section.Index = SectionCount++; 3840b57cec5SDimitry Andric } 3850b57cec5SDimitry Andric 386349cc55cSDimitry Andric // Write a string with extra paddings for trailing alignment 387349cc55cSDimitry Andric // TODO: support alignment at asm and llvm level? 388349cc55cSDimitry Andric void WasmObjectWriter::writeStringWithAlignment(const StringRef Str, 389349cc55cSDimitry Andric unsigned Alignment) { 390349cc55cSDimitry Andric 391349cc55cSDimitry Andric // Calculate the encoded size of str length and add pads based on it and 392349cc55cSDimitry Andric // alignment. 393349cc55cSDimitry Andric raw_null_ostream NullOS; 394349cc55cSDimitry Andric uint64_t StrSizeLength = encodeULEB128(Str.size(), NullOS); 395349cc55cSDimitry Andric uint64_t Offset = W->OS.tell() + StrSizeLength + Str.size(); 396349cc55cSDimitry Andric uint64_t Paddings = offsetToAlignment(Offset, Align(Alignment)); 397349cc55cSDimitry Andric Offset += Paddings; 398349cc55cSDimitry Andric 399349cc55cSDimitry Andric // LEB128 greater than 5 bytes is invalid 400349cc55cSDimitry Andric assert((StrSizeLength + Paddings) <= 5 && "too long string to align"); 401349cc55cSDimitry Andric 402349cc55cSDimitry Andric encodeSLEB128(Str.size(), W->OS, StrSizeLength + Paddings); 403349cc55cSDimitry Andric W->OS << Str; 404349cc55cSDimitry Andric 405349cc55cSDimitry Andric assert(W->OS.tell() == Offset && "invalid padding"); 406349cc55cSDimitry Andric } 407349cc55cSDimitry Andric 4080b57cec5SDimitry Andric void WasmObjectWriter::startCustomSection(SectionBookkeeping &Section, 4090b57cec5SDimitry Andric StringRef Name) { 4100b57cec5SDimitry Andric LLVM_DEBUG(dbgs() << "startCustomSection " << Name << "\n"); 4110b57cec5SDimitry Andric startSection(Section, wasm::WASM_SEC_CUSTOM); 4120b57cec5SDimitry Andric 4130b57cec5SDimitry Andric // The position where the section header ends, for measuring its size. 414e8d8bef9SDimitry Andric Section.PayloadOffset = W->OS.tell(); 4150b57cec5SDimitry Andric 4160b57cec5SDimitry Andric // Custom sections in wasm also have a string identifier. 417349cc55cSDimitry Andric if (Name != "__clangast") { 4180b57cec5SDimitry Andric writeString(Name); 419349cc55cSDimitry Andric } else { 420349cc55cSDimitry Andric // The on-disk hashtable in clangast needs to be aligned by 4 bytes. 421349cc55cSDimitry Andric writeStringWithAlignment(Name, 4); 422349cc55cSDimitry Andric } 4230b57cec5SDimitry Andric 4240b57cec5SDimitry Andric // The position where the custom section starts. 425e8d8bef9SDimitry Andric Section.ContentsOffset = W->OS.tell(); 4260b57cec5SDimitry Andric } 4270b57cec5SDimitry Andric 4280b57cec5SDimitry Andric // Now that the section is complete and we know how big it is, patch up the 4290b57cec5SDimitry Andric // section size field at the start of the section. 4300b57cec5SDimitry Andric void WasmObjectWriter::endSection(SectionBookkeeping &Section) { 431e8d8bef9SDimitry Andric uint64_t Size = W->OS.tell(); 4320b57cec5SDimitry Andric // /dev/null doesn't support seek/tell and can report offset of 0. 4330b57cec5SDimitry Andric // Simply skip this patching in that case. 4340b57cec5SDimitry Andric if (!Size) 4350b57cec5SDimitry Andric return; 4360b57cec5SDimitry Andric 4370b57cec5SDimitry Andric Size -= Section.PayloadOffset; 4380b57cec5SDimitry Andric if (uint32_t(Size) != Size) 4390b57cec5SDimitry Andric report_fatal_error("section size does not fit in a uint32_t"); 4400b57cec5SDimitry Andric 4410b57cec5SDimitry Andric LLVM_DEBUG(dbgs() << "endSection size=" << Size << "\n"); 4420b57cec5SDimitry Andric 4430b57cec5SDimitry Andric // Write the final section size to the payload_len field, which follows 4440b57cec5SDimitry Andric // the section id byte. 445fb03ea46SDimitry Andric writePatchableU32(static_cast<raw_pwrite_stream &>(W->OS), Size, 4460b57cec5SDimitry Andric Section.SizeOffset); 4470b57cec5SDimitry Andric } 4480b57cec5SDimitry Andric 4490b57cec5SDimitry Andric // Emit the Wasm header. 4500b57cec5SDimitry Andric void WasmObjectWriter::writeHeader(const MCAssembler &Asm) { 451e8d8bef9SDimitry Andric W->OS.write(wasm::WasmMagic, sizeof(wasm::WasmMagic)); 452e8d8bef9SDimitry Andric W->write<uint32_t>(wasm::WasmVersion); 4530b57cec5SDimitry Andric } 4540b57cec5SDimitry Andric 4550b57cec5SDimitry Andric void WasmObjectWriter::executePostLayoutBinding(MCAssembler &Asm, 4560b57cec5SDimitry Andric const MCAsmLayout &Layout) { 457fe6060f1SDimitry Andric // Some compilation units require the indirect function table to be present 458fe6060f1SDimitry Andric // but don't explicitly reference it. This is the case for call_indirect 459fe6060f1SDimitry Andric // without the reference-types feature, and also function bitcasts in all 460fe6060f1SDimitry Andric // cases. In those cases the __indirect_function_table has the 461fe6060f1SDimitry Andric // WASM_SYMBOL_NO_STRIP attribute. Here we make sure this symbol makes it to 462fe6060f1SDimitry Andric // the assembler, if needed. 463fe6060f1SDimitry Andric if (auto *Sym = Asm.getContext().lookupSymbol("__indirect_function_table")) { 464fe6060f1SDimitry Andric const auto *WasmSym = static_cast<const MCSymbolWasm *>(Sym); 465fe6060f1SDimitry Andric if (WasmSym->isNoStrip()) 466e8d8bef9SDimitry Andric Asm.registerSymbol(*Sym); 467fe6060f1SDimitry Andric } 468e8d8bef9SDimitry Andric 4690b57cec5SDimitry Andric // Build a map of sections to the function that defines them, for use 4700b57cec5SDimitry Andric // in recordRelocation. 4710b57cec5SDimitry Andric for (const MCSymbol &S : Asm.symbols()) { 4720b57cec5SDimitry Andric const auto &WS = static_cast<const MCSymbolWasm &>(S); 4730b57cec5SDimitry Andric if (WS.isDefined() && WS.isFunction() && !WS.isVariable()) { 4740b57cec5SDimitry Andric const auto &Sec = static_cast<const MCSectionWasm &>(S.getSection()); 4750b57cec5SDimitry Andric auto Pair = SectionFunctions.insert(std::make_pair(&Sec, &S)); 4760b57cec5SDimitry Andric if (!Pair.second) 4770b57cec5SDimitry Andric report_fatal_error("section already has a defining function: " + 4785ffd83dbSDimitry Andric Sec.getName()); 4790b57cec5SDimitry Andric } 4800b57cec5SDimitry Andric } 4810b57cec5SDimitry Andric } 4820b57cec5SDimitry Andric 4830b57cec5SDimitry Andric void WasmObjectWriter::recordRelocation(MCAssembler &Asm, 4840b57cec5SDimitry Andric const MCAsmLayout &Layout, 4850b57cec5SDimitry Andric const MCFragment *Fragment, 4860b57cec5SDimitry Andric const MCFixup &Fixup, MCValue Target, 4870b57cec5SDimitry Andric uint64_t &FixedValue) { 4888bcb0991SDimitry Andric // The WebAssembly backend should never generate FKF_IsPCRel fixups 4898bcb0991SDimitry Andric assert(!(Asm.getBackend().getFixupKindInfo(Fixup.getKind()).Flags & 4908bcb0991SDimitry Andric MCFixupKindInfo::FKF_IsPCRel)); 4918bcb0991SDimitry Andric 4920b57cec5SDimitry Andric const auto &FixupSection = cast<MCSectionWasm>(*Fragment->getParent()); 4930b57cec5SDimitry Andric uint64_t C = Target.getConstant(); 4940b57cec5SDimitry Andric uint64_t FixupOffset = Layout.getFragmentOffset(Fragment) + Fixup.getOffset(); 4950b57cec5SDimitry Andric MCContext &Ctx = Asm.getContext(); 496fe6060f1SDimitry Andric bool IsLocRel = false; 4970b57cec5SDimitry Andric 4980b57cec5SDimitry Andric if (const MCSymbolRefExpr *RefB = Target.getSymB()) { 499fe6060f1SDimitry Andric 5008bcb0991SDimitry Andric const auto &SymB = cast<MCSymbolWasm>(RefB->getSymbol()); 501fe6060f1SDimitry Andric 502fe6060f1SDimitry Andric if (FixupSection.getKind().isText()) { 503fe6060f1SDimitry Andric Ctx.reportError(Fixup.getLoc(), 5040b57cec5SDimitry Andric Twine("symbol '") + SymB.getName() + 505fe6060f1SDimitry Andric "' unsupported subtraction expression used in " 506fe6060f1SDimitry Andric "relocation in code section."); 5070b57cec5SDimitry Andric return; 5080b57cec5SDimitry Andric } 5090b57cec5SDimitry Andric 510fe6060f1SDimitry Andric if (SymB.isUndefined()) { 511fe6060f1SDimitry Andric Ctx.reportError(Fixup.getLoc(), 512fe6060f1SDimitry Andric Twine("symbol '") + SymB.getName() + 513fe6060f1SDimitry Andric "' can not be undefined in a subtraction expression"); 514fe6060f1SDimitry Andric return; 515fe6060f1SDimitry Andric } 516fe6060f1SDimitry Andric const MCSection &SecB = SymB.getSection(); 517fe6060f1SDimitry Andric if (&SecB != &FixupSection) { 518fe6060f1SDimitry Andric Ctx.reportError(Fixup.getLoc(), 519fe6060f1SDimitry Andric Twine("symbol '") + SymB.getName() + 520fe6060f1SDimitry Andric "' can not be placed in a different section"); 521fe6060f1SDimitry Andric return; 522fe6060f1SDimitry Andric } 523fe6060f1SDimitry Andric IsLocRel = true; 524fe6060f1SDimitry Andric C += FixupOffset - Layout.getSymbolOffset(SymB); 525fe6060f1SDimitry Andric } 526fe6060f1SDimitry Andric 5270b57cec5SDimitry Andric // We either rejected the fixup or folded B into C at this point. 5280b57cec5SDimitry Andric const MCSymbolRefExpr *RefA = Target.getSymA(); 5298bcb0991SDimitry Andric const auto *SymA = cast<MCSymbolWasm>(&RefA->getSymbol()); 5300b57cec5SDimitry Andric 5315ffd83dbSDimitry Andric // The .init_array isn't translated as data, so don't do relocations in it. 5325f757f3fSDimitry Andric if (FixupSection.getName().starts_with(".init_array")) { 5335ffd83dbSDimitry Andric SymA->setUsedInInitArray(); 5345ffd83dbSDimitry Andric return; 5355ffd83dbSDimitry Andric } 5365ffd83dbSDimitry Andric 5378bcb0991SDimitry Andric if (SymA->isVariable()) { 5380b57cec5SDimitry Andric const MCExpr *Expr = SymA->getVariableValue(); 5395ffd83dbSDimitry Andric if (const auto *Inner = dyn_cast<MCSymbolRefExpr>(Expr)) 5400b57cec5SDimitry Andric if (Inner->getKind() == MCSymbolRefExpr::VK_WEAKREF) 5410b57cec5SDimitry Andric llvm_unreachable("weakref used in reloc not yet implemented"); 5420b57cec5SDimitry Andric } 5430b57cec5SDimitry Andric 5440b57cec5SDimitry Andric // Put any constant offset in an addend. Offsets can be negative, and 5450b57cec5SDimitry Andric // LLVM expects wrapping, in contrast to wasm's immediates which can't 5460b57cec5SDimitry Andric // be negative and don't wrap. 5470b57cec5SDimitry Andric FixedValue = 0; 5480b57cec5SDimitry Andric 549fe6060f1SDimitry Andric unsigned Type = 550fe6060f1SDimitry Andric TargetObjectWriter->getRelocType(Target, Fixup, FixupSection, IsLocRel); 5510b57cec5SDimitry Andric 5520b57cec5SDimitry Andric // Absolute offset within a section or a function. 5535f757f3fSDimitry Andric // Currently only supported for metadata sections. 5540b57cec5SDimitry Andric // See: test/MC/WebAssembly/blockaddress.ll 555fe6060f1SDimitry Andric if ((Type == wasm::R_WASM_FUNCTION_OFFSET_I32 || 556e8d8bef9SDimitry Andric Type == wasm::R_WASM_FUNCTION_OFFSET_I64 || 557fe6060f1SDimitry Andric Type == wasm::R_WASM_SECTION_OFFSET_I32) && 558fe6060f1SDimitry Andric SymA->isDefined()) { 559fe6060f1SDimitry Andric // SymA can be a temp data symbol that represents a function (in which case 560fe6060f1SDimitry Andric // it needs to be replaced by the section symbol), [XXX and it apparently 561fe6060f1SDimitry Andric // later gets changed again to a func symbol?] or it can be a real 562fe6060f1SDimitry Andric // function symbol, in which case it can be left as-is. 563fe6060f1SDimitry Andric 5640b57cec5SDimitry Andric if (!FixupSection.getKind().isMetadata()) 5650b57cec5SDimitry Andric report_fatal_error("relocations for function or section offsets are " 5660b57cec5SDimitry Andric "only supported in metadata sections"); 5670b57cec5SDimitry Andric 5680b57cec5SDimitry Andric const MCSymbol *SectionSymbol = nullptr; 5690b57cec5SDimitry Andric const MCSection &SecA = SymA->getSection(); 570fe6060f1SDimitry Andric if (SecA.getKind().isText()) { 571fe6060f1SDimitry Andric auto SecSymIt = SectionFunctions.find(&SecA); 572fe6060f1SDimitry Andric if (SecSymIt == SectionFunctions.end()) 573fe6060f1SDimitry Andric report_fatal_error("section doesn\'t have defining symbol"); 574fe6060f1SDimitry Andric SectionSymbol = SecSymIt->second; 575fe6060f1SDimitry Andric } else { 5760b57cec5SDimitry Andric SectionSymbol = SecA.getBeginSymbol(); 577fe6060f1SDimitry Andric } 5780b57cec5SDimitry Andric if (!SectionSymbol) 5790b57cec5SDimitry Andric report_fatal_error("section symbol is required for relocation"); 5800b57cec5SDimitry Andric 5810b57cec5SDimitry Andric C += Layout.getSymbolOffset(*SymA); 5820b57cec5SDimitry Andric SymA = cast<MCSymbolWasm>(SectionSymbol); 5830b57cec5SDimitry Andric } 5840b57cec5SDimitry Andric 585e8d8bef9SDimitry Andric if (Type == wasm::R_WASM_TABLE_INDEX_REL_SLEB || 586fe6060f1SDimitry Andric Type == wasm::R_WASM_TABLE_INDEX_REL_SLEB64 || 587e8d8bef9SDimitry Andric Type == wasm::R_WASM_TABLE_INDEX_SLEB || 588e8d8bef9SDimitry Andric Type == wasm::R_WASM_TABLE_INDEX_SLEB64 || 589e8d8bef9SDimitry Andric Type == wasm::R_WASM_TABLE_INDEX_I32 || 590e8d8bef9SDimitry Andric Type == wasm::R_WASM_TABLE_INDEX_I64) { 591e8d8bef9SDimitry Andric // TABLE_INDEX relocs implicitly use the default indirect function table. 592fe6060f1SDimitry Andric // We require the function table to have already been defined. 593e8d8bef9SDimitry Andric auto TableName = "__indirect_function_table"; 594e8d8bef9SDimitry Andric MCSymbolWasm *Sym = cast_or_null<MCSymbolWasm>(Ctx.lookupSymbol(TableName)); 595fe6060f1SDimitry Andric if (!Sym) { 596fe6060f1SDimitry Andric report_fatal_error("missing indirect function table symbol"); 597e8d8bef9SDimitry Andric } else { 598fe6060f1SDimitry Andric if (!Sym->isFunctionTable()) 599fe6060f1SDimitry Andric report_fatal_error("__indirect_function_table symbol has wrong type"); 600fe6060f1SDimitry Andric // Ensure that __indirect_function_table reaches the output. 601fe6060f1SDimitry Andric Sym->setNoStrip(); 602e8d8bef9SDimitry Andric Asm.registerSymbol(*Sym); 603e8d8bef9SDimitry Andric } 604fe6060f1SDimitry Andric } 605e8d8bef9SDimitry Andric 6060b57cec5SDimitry Andric // Relocation other than R_WASM_TYPE_INDEX_LEB are required to be 6070b57cec5SDimitry Andric // against a named symbol. 6080b57cec5SDimitry Andric if (Type != wasm::R_WASM_TYPE_INDEX_LEB) { 6090b57cec5SDimitry Andric if (SymA->getName().empty()) 6100b57cec5SDimitry Andric report_fatal_error("relocations against un-named temporaries are not yet " 6110b57cec5SDimitry Andric "supported by wasm"); 6120b57cec5SDimitry Andric 6130b57cec5SDimitry Andric SymA->setUsedInReloc(); 6140b57cec5SDimitry Andric } 6150b57cec5SDimitry Andric 616349cc55cSDimitry Andric switch (RefA->getKind()) { 617349cc55cSDimitry Andric case MCSymbolRefExpr::VK_GOT: 618349cc55cSDimitry Andric case MCSymbolRefExpr::VK_WASM_GOT_TLS: 6190b57cec5SDimitry Andric SymA->setUsedInGOT(); 620349cc55cSDimitry Andric break; 621349cc55cSDimitry Andric default: 622349cc55cSDimitry Andric break; 623349cc55cSDimitry Andric } 6240b57cec5SDimitry Andric 6250b57cec5SDimitry Andric WasmRelocationEntry Rec(FixupOffset, SymA, C, Type, &FixupSection); 6260b57cec5SDimitry Andric LLVM_DEBUG(dbgs() << "WasmReloc: " << Rec << "\n"); 6270b57cec5SDimitry Andric 6280b57cec5SDimitry Andric if (FixupSection.isWasmData()) { 6290b57cec5SDimitry Andric DataRelocations.push_back(Rec); 6300b57cec5SDimitry Andric } else if (FixupSection.getKind().isText()) { 6310b57cec5SDimitry Andric CodeRelocations.push_back(Rec); 6320b57cec5SDimitry Andric } else if (FixupSection.getKind().isMetadata()) { 6330b57cec5SDimitry Andric CustomSectionsRelocations[&FixupSection].push_back(Rec); 6340b57cec5SDimitry Andric } else { 6350b57cec5SDimitry Andric llvm_unreachable("unexpected section type"); 6360b57cec5SDimitry Andric } 6370b57cec5SDimitry Andric } 6380b57cec5SDimitry Andric 6390b57cec5SDimitry Andric // Compute a value to write into the code at the location covered 6400b57cec5SDimitry Andric // by RelEntry. This value isn't used by the static linker; it just serves 6410b57cec5SDimitry Andric // to make the object format more readable and more likely to be directly 6420b57cec5SDimitry Andric // useable. 6435ffd83dbSDimitry Andric uint64_t 6445ffd83dbSDimitry Andric WasmObjectWriter::getProvisionalValue(const WasmRelocationEntry &RelEntry, 6455ffd83dbSDimitry Andric const MCAsmLayout &Layout) { 6465ffd83dbSDimitry Andric if ((RelEntry.Type == wasm::R_WASM_GLOBAL_INDEX_LEB || 6475ffd83dbSDimitry Andric RelEntry.Type == wasm::R_WASM_GLOBAL_INDEX_I32) && 6485ffd83dbSDimitry Andric !RelEntry.Symbol->isGlobal()) { 6490b57cec5SDimitry Andric assert(GOTIndices.count(RelEntry.Symbol) > 0 && "symbol not found in GOT index space"); 6500b57cec5SDimitry Andric return GOTIndices[RelEntry.Symbol]; 6510b57cec5SDimitry Andric } 6520b57cec5SDimitry Andric 6530b57cec5SDimitry Andric switch (RelEntry.Type) { 6540b57cec5SDimitry Andric case wasm::R_WASM_TABLE_INDEX_REL_SLEB: 655fe6060f1SDimitry Andric case wasm::R_WASM_TABLE_INDEX_REL_SLEB64: 6560b57cec5SDimitry Andric case wasm::R_WASM_TABLE_INDEX_SLEB: 657e8d8bef9SDimitry Andric case wasm::R_WASM_TABLE_INDEX_SLEB64: 658e8d8bef9SDimitry Andric case wasm::R_WASM_TABLE_INDEX_I32: 659e8d8bef9SDimitry Andric case wasm::R_WASM_TABLE_INDEX_I64: { 6600b57cec5SDimitry Andric // Provisional value is table address of the resolved symbol itself 6615ffd83dbSDimitry Andric const MCSymbolWasm *Base = 6625ffd83dbSDimitry Andric cast<MCSymbolWasm>(Layout.getBaseSymbol(*RelEntry.Symbol)); 6635ffd83dbSDimitry Andric assert(Base->isFunction()); 664fe6060f1SDimitry Andric if (RelEntry.Type == wasm::R_WASM_TABLE_INDEX_REL_SLEB || 665fe6060f1SDimitry Andric RelEntry.Type == wasm::R_WASM_TABLE_INDEX_REL_SLEB64) 6665ffd83dbSDimitry Andric return TableIndices[Base] - InitialTableOffset; 6675ffd83dbSDimitry Andric else 6685ffd83dbSDimitry Andric return TableIndices[Base]; 6690b57cec5SDimitry Andric } 6700b57cec5SDimitry Andric case wasm::R_WASM_TYPE_INDEX_LEB: 6710b57cec5SDimitry Andric // Provisional value is same as the index 6720b57cec5SDimitry Andric return getRelocationIndexValue(RelEntry); 6730b57cec5SDimitry Andric case wasm::R_WASM_FUNCTION_INDEX_LEB: 67406c3fb27SDimitry Andric case wasm::R_WASM_FUNCTION_INDEX_I32: 6750b57cec5SDimitry Andric case wasm::R_WASM_GLOBAL_INDEX_LEB: 6765ffd83dbSDimitry Andric case wasm::R_WASM_GLOBAL_INDEX_I32: 677fe6060f1SDimitry Andric case wasm::R_WASM_TAG_INDEX_LEB: 678e8d8bef9SDimitry Andric case wasm::R_WASM_TABLE_NUMBER_LEB: 679fe6060f1SDimitry Andric // Provisional value is function/global/tag Wasm index 6800b57cec5SDimitry Andric assert(WasmIndices.count(RelEntry.Symbol) > 0 && "symbol not found in wasm index space"); 6810b57cec5SDimitry Andric return WasmIndices[RelEntry.Symbol]; 6820b57cec5SDimitry Andric case wasm::R_WASM_FUNCTION_OFFSET_I32: 683e8d8bef9SDimitry Andric case wasm::R_WASM_FUNCTION_OFFSET_I64: 6840b57cec5SDimitry Andric case wasm::R_WASM_SECTION_OFFSET_I32: { 685fe6060f1SDimitry Andric if (!RelEntry.Symbol->isDefined()) 686fe6060f1SDimitry Andric return 0; 6870b57cec5SDimitry Andric const auto &Section = 6880b57cec5SDimitry Andric static_cast<const MCSectionWasm &>(RelEntry.Symbol->getSection()); 6890b57cec5SDimitry Andric return Section.getSectionOffset() + RelEntry.Addend; 6900b57cec5SDimitry Andric } 6910b57cec5SDimitry Andric case wasm::R_WASM_MEMORY_ADDR_LEB: 6925ffd83dbSDimitry Andric case wasm::R_WASM_MEMORY_ADDR_LEB64: 6935ffd83dbSDimitry Andric case wasm::R_WASM_MEMORY_ADDR_SLEB: 6945ffd83dbSDimitry Andric case wasm::R_WASM_MEMORY_ADDR_SLEB64: 6950b57cec5SDimitry Andric case wasm::R_WASM_MEMORY_ADDR_REL_SLEB: 6965ffd83dbSDimitry Andric case wasm::R_WASM_MEMORY_ADDR_REL_SLEB64: 6975ffd83dbSDimitry Andric case wasm::R_WASM_MEMORY_ADDR_I32: 698e8d8bef9SDimitry Andric case wasm::R_WASM_MEMORY_ADDR_I64: 699fe6060f1SDimitry Andric case wasm::R_WASM_MEMORY_ADDR_TLS_SLEB: 700fe6060f1SDimitry Andric case wasm::R_WASM_MEMORY_ADDR_TLS_SLEB64: 701fe6060f1SDimitry Andric case wasm::R_WASM_MEMORY_ADDR_LOCREL_I32: { 702e8d8bef9SDimitry Andric // Provisional value is address of the global plus the offset 7030b57cec5SDimitry Andric // For undefined symbols, use zero 704fe6060f1SDimitry Andric if (!RelEntry.Symbol->isDefined()) 7050b57cec5SDimitry Andric return 0; 706fe6060f1SDimitry Andric const wasm::WasmDataReference &SymRef = DataLocations[RelEntry.Symbol]; 707fe6060f1SDimitry Andric const WasmDataSegment &Segment = DataSegments[SymRef.Segment]; 7080b57cec5SDimitry Andric // Ignore overflow. LLVM allows address arithmetic to silently wrap. 709fe6060f1SDimitry Andric return Segment.Offset + SymRef.Offset + RelEntry.Addend; 7100b57cec5SDimitry Andric } 7110b57cec5SDimitry Andric default: 7120b57cec5SDimitry Andric llvm_unreachable("invalid relocation type"); 7130b57cec5SDimitry Andric } 7140b57cec5SDimitry Andric } 7150b57cec5SDimitry Andric 7160b57cec5SDimitry Andric static void addData(SmallVectorImpl<char> &DataBytes, 7170b57cec5SDimitry Andric MCSectionWasm &DataSection) { 7185ffd83dbSDimitry Andric LLVM_DEBUG(errs() << "addData: " << DataSection.getName() << "\n"); 7190b57cec5SDimitry Andric 720bdd1243dSDimitry Andric DataBytes.resize(alignTo(DataBytes.size(), DataSection.getAlign())); 7210b57cec5SDimitry Andric 7220b57cec5SDimitry Andric for (const MCFragment &Frag : DataSection) { 7230b57cec5SDimitry Andric if (Frag.hasInstructions()) 7240b57cec5SDimitry Andric report_fatal_error("only data supported in data sections"); 7250b57cec5SDimitry Andric 7260b57cec5SDimitry Andric if (auto *Align = dyn_cast<MCAlignFragment>(&Frag)) { 7270b57cec5SDimitry Andric if (Align->getValueSize() != 1) 7280b57cec5SDimitry Andric report_fatal_error("only byte values supported for alignment"); 7290b57cec5SDimitry Andric // If nops are requested, use zeros, as this is the data section. 7300b57cec5SDimitry Andric uint8_t Value = Align->hasEmitNops() ? 0 : Align->getValue(); 7310b57cec5SDimitry Andric uint64_t Size = 7320b57cec5SDimitry Andric std::min<uint64_t>(alignTo(DataBytes.size(), Align->getAlignment()), 7330b57cec5SDimitry Andric DataBytes.size() + Align->getMaxBytesToEmit()); 7340b57cec5SDimitry Andric DataBytes.resize(Size, Value); 7350b57cec5SDimitry Andric } else if (auto *Fill = dyn_cast<MCFillFragment>(&Frag)) { 7360b57cec5SDimitry Andric int64_t NumValues; 7370b57cec5SDimitry Andric if (!Fill->getNumValues().evaluateAsAbsolute(NumValues)) 7380b57cec5SDimitry Andric llvm_unreachable("The fill should be an assembler constant"); 7390b57cec5SDimitry Andric DataBytes.insert(DataBytes.end(), Fill->getValueSize() * NumValues, 7400b57cec5SDimitry Andric Fill->getValue()); 7410b57cec5SDimitry Andric } else if (auto *LEB = dyn_cast<MCLEBFragment>(&Frag)) { 7420b57cec5SDimitry Andric const SmallVectorImpl<char> &Contents = LEB->getContents(); 743e8d8bef9SDimitry Andric llvm::append_range(DataBytes, Contents); 7440b57cec5SDimitry Andric } else { 7450b57cec5SDimitry Andric const auto &DataFrag = cast<MCDataFragment>(Frag); 7460b57cec5SDimitry Andric const SmallVectorImpl<char> &Contents = DataFrag.getContents(); 747e8d8bef9SDimitry Andric llvm::append_range(DataBytes, Contents); 7480b57cec5SDimitry Andric } 7490b57cec5SDimitry Andric } 7500b57cec5SDimitry Andric 7510b57cec5SDimitry Andric LLVM_DEBUG(dbgs() << "addData -> " << DataBytes.size() << "\n"); 7520b57cec5SDimitry Andric } 7530b57cec5SDimitry Andric 7540b57cec5SDimitry Andric uint32_t 7550b57cec5SDimitry Andric WasmObjectWriter::getRelocationIndexValue(const WasmRelocationEntry &RelEntry) { 7560b57cec5SDimitry Andric if (RelEntry.Type == wasm::R_WASM_TYPE_INDEX_LEB) { 7570b57cec5SDimitry Andric if (!TypeIndices.count(RelEntry.Symbol)) 7580b57cec5SDimitry Andric report_fatal_error("symbol not found in type index space: " + 7590b57cec5SDimitry Andric RelEntry.Symbol->getName()); 7600b57cec5SDimitry Andric return TypeIndices[RelEntry.Symbol]; 7610b57cec5SDimitry Andric } 7620b57cec5SDimitry Andric 7630b57cec5SDimitry Andric return RelEntry.Symbol->getIndex(); 7640b57cec5SDimitry Andric } 7650b57cec5SDimitry Andric 7660b57cec5SDimitry Andric // Apply the portions of the relocation records that we can handle ourselves 7670b57cec5SDimitry Andric // directly. 7680b57cec5SDimitry Andric void WasmObjectWriter::applyRelocations( 7695ffd83dbSDimitry Andric ArrayRef<WasmRelocationEntry> Relocations, uint64_t ContentsOffset, 7705ffd83dbSDimitry Andric const MCAsmLayout &Layout) { 771e8d8bef9SDimitry Andric auto &Stream = static_cast<raw_pwrite_stream &>(W->OS); 7720b57cec5SDimitry Andric for (const WasmRelocationEntry &RelEntry : Relocations) { 7730b57cec5SDimitry Andric uint64_t Offset = ContentsOffset + 7740b57cec5SDimitry Andric RelEntry.FixupSection->getSectionOffset() + 7750b57cec5SDimitry Andric RelEntry.Offset; 7760b57cec5SDimitry Andric 7770b57cec5SDimitry Andric LLVM_DEBUG(dbgs() << "applyRelocation: " << RelEntry << "\n"); 778fb03ea46SDimitry Andric uint64_t Value = getProvisionalValue(RelEntry, Layout); 7790b57cec5SDimitry Andric 7800b57cec5SDimitry Andric switch (RelEntry.Type) { 7810b57cec5SDimitry Andric case wasm::R_WASM_FUNCTION_INDEX_LEB: 7820b57cec5SDimitry Andric case wasm::R_WASM_TYPE_INDEX_LEB: 7830b57cec5SDimitry Andric case wasm::R_WASM_GLOBAL_INDEX_LEB: 7840b57cec5SDimitry Andric case wasm::R_WASM_MEMORY_ADDR_LEB: 785fe6060f1SDimitry Andric case wasm::R_WASM_TAG_INDEX_LEB: 786e8d8bef9SDimitry Andric case wasm::R_WASM_TABLE_NUMBER_LEB: 787fb03ea46SDimitry Andric writePatchableU32(Stream, Value, Offset); 7885ffd83dbSDimitry Andric break; 7895ffd83dbSDimitry Andric case wasm::R_WASM_MEMORY_ADDR_LEB64: 790fb03ea46SDimitry Andric writePatchableU64(Stream, Value, Offset); 7910b57cec5SDimitry Andric break; 7920b57cec5SDimitry Andric case wasm::R_WASM_TABLE_INDEX_I32: 7930b57cec5SDimitry Andric case wasm::R_WASM_MEMORY_ADDR_I32: 7940b57cec5SDimitry Andric case wasm::R_WASM_FUNCTION_OFFSET_I32: 79506c3fb27SDimitry Andric case wasm::R_WASM_FUNCTION_INDEX_I32: 7960b57cec5SDimitry Andric case wasm::R_WASM_SECTION_OFFSET_I32: 7975ffd83dbSDimitry Andric case wasm::R_WASM_GLOBAL_INDEX_I32: 798fe6060f1SDimitry Andric case wasm::R_WASM_MEMORY_ADDR_LOCREL_I32: 7995ffd83dbSDimitry Andric patchI32(Stream, Value, Offset); 8005ffd83dbSDimitry Andric break; 801e8d8bef9SDimitry Andric case wasm::R_WASM_TABLE_INDEX_I64: 8025ffd83dbSDimitry Andric case wasm::R_WASM_MEMORY_ADDR_I64: 803e8d8bef9SDimitry Andric case wasm::R_WASM_FUNCTION_OFFSET_I64: 8045ffd83dbSDimitry Andric patchI64(Stream, Value, Offset); 8050b57cec5SDimitry Andric break; 8060b57cec5SDimitry Andric case wasm::R_WASM_TABLE_INDEX_SLEB: 8070b57cec5SDimitry Andric case wasm::R_WASM_TABLE_INDEX_REL_SLEB: 8080b57cec5SDimitry Andric case wasm::R_WASM_MEMORY_ADDR_SLEB: 8090b57cec5SDimitry Andric case wasm::R_WASM_MEMORY_ADDR_REL_SLEB: 810e8d8bef9SDimitry Andric case wasm::R_WASM_MEMORY_ADDR_TLS_SLEB: 811fb03ea46SDimitry Andric writePatchableS32(Stream, Value, Offset); 8125ffd83dbSDimitry Andric break; 813e8d8bef9SDimitry Andric case wasm::R_WASM_TABLE_INDEX_SLEB64: 814fe6060f1SDimitry Andric case wasm::R_WASM_TABLE_INDEX_REL_SLEB64: 8155ffd83dbSDimitry Andric case wasm::R_WASM_MEMORY_ADDR_SLEB64: 8165ffd83dbSDimitry Andric case wasm::R_WASM_MEMORY_ADDR_REL_SLEB64: 817fe6060f1SDimitry Andric case wasm::R_WASM_MEMORY_ADDR_TLS_SLEB64: 818fb03ea46SDimitry Andric writePatchableS64(Stream, Value, Offset); 8190b57cec5SDimitry Andric break; 8200b57cec5SDimitry Andric default: 8210b57cec5SDimitry Andric llvm_unreachable("invalid relocation type"); 8220b57cec5SDimitry Andric } 8230b57cec5SDimitry Andric } 8240b57cec5SDimitry Andric } 8250b57cec5SDimitry Andric 826e8d8bef9SDimitry Andric void WasmObjectWriter::writeTypeSection( 827e8d8bef9SDimitry Andric ArrayRef<wasm::WasmSignature> Signatures) { 8280b57cec5SDimitry Andric if (Signatures.empty()) 8290b57cec5SDimitry Andric return; 8300b57cec5SDimitry Andric 8310b57cec5SDimitry Andric SectionBookkeeping Section; 8320b57cec5SDimitry Andric startSection(Section, wasm::WASM_SEC_TYPE); 8330b57cec5SDimitry Andric 834e8d8bef9SDimitry Andric encodeULEB128(Signatures.size(), W->OS); 8350b57cec5SDimitry Andric 836e8d8bef9SDimitry Andric for (const wasm::WasmSignature &Sig : Signatures) { 837e8d8bef9SDimitry Andric W->OS << char(wasm::WASM_TYPE_FUNC); 838e8d8bef9SDimitry Andric encodeULEB128(Sig.Params.size(), W->OS); 8390b57cec5SDimitry Andric for (wasm::ValType Ty : Sig.Params) 8400b57cec5SDimitry Andric writeValueType(Ty); 841e8d8bef9SDimitry Andric encodeULEB128(Sig.Returns.size(), W->OS); 8420b57cec5SDimitry Andric for (wasm::ValType Ty : Sig.Returns) 8430b57cec5SDimitry Andric writeValueType(Ty); 8440b57cec5SDimitry Andric } 8450b57cec5SDimitry Andric 8460b57cec5SDimitry Andric endSection(Section); 8470b57cec5SDimitry Andric } 8480b57cec5SDimitry Andric 8490b57cec5SDimitry Andric void WasmObjectWriter::writeImportSection(ArrayRef<wasm::WasmImport> Imports, 8505ffd83dbSDimitry Andric uint64_t DataSize, 8510b57cec5SDimitry Andric uint32_t NumElements) { 8520b57cec5SDimitry Andric if (Imports.empty()) 8530b57cec5SDimitry Andric return; 8540b57cec5SDimitry Andric 8555ffd83dbSDimitry Andric uint64_t NumPages = (DataSize + wasm::WasmPageSize - 1) / wasm::WasmPageSize; 8560b57cec5SDimitry Andric 8570b57cec5SDimitry Andric SectionBookkeeping Section; 8580b57cec5SDimitry Andric startSection(Section, wasm::WASM_SEC_IMPORT); 8590b57cec5SDimitry Andric 860e8d8bef9SDimitry Andric encodeULEB128(Imports.size(), W->OS); 8610b57cec5SDimitry Andric for (const wasm::WasmImport &Import : Imports) { 8620b57cec5SDimitry Andric writeString(Import.Module); 8630b57cec5SDimitry Andric writeString(Import.Field); 864e8d8bef9SDimitry Andric W->OS << char(Import.Kind); 8650b57cec5SDimitry Andric 8660b57cec5SDimitry Andric switch (Import.Kind) { 8670b57cec5SDimitry Andric case wasm::WASM_EXTERNAL_FUNCTION: 868e8d8bef9SDimitry Andric encodeULEB128(Import.SigIndex, W->OS); 8690b57cec5SDimitry Andric break; 8700b57cec5SDimitry Andric case wasm::WASM_EXTERNAL_GLOBAL: 871e8d8bef9SDimitry Andric W->OS << char(Import.Global.Type); 872e8d8bef9SDimitry Andric W->OS << char(Import.Global.Mutable ? 1 : 0); 8730b57cec5SDimitry Andric break; 8740b57cec5SDimitry Andric case wasm::WASM_EXTERNAL_MEMORY: 875e8d8bef9SDimitry Andric encodeULEB128(Import.Memory.Flags, W->OS); 876e8d8bef9SDimitry Andric encodeULEB128(NumPages, W->OS); // initial 8770b57cec5SDimitry Andric break; 8780b57cec5SDimitry Andric case wasm::WASM_EXTERNAL_TABLE: 879e8d8bef9SDimitry Andric W->OS << char(Import.Table.ElemType); 880e8d8bef9SDimitry Andric encodeULEB128(0, W->OS); // flags 881e8d8bef9SDimitry Andric encodeULEB128(NumElements, W->OS); // initial 8820b57cec5SDimitry Andric break; 883fe6060f1SDimitry Andric case wasm::WASM_EXTERNAL_TAG: 884349cc55cSDimitry Andric W->OS << char(0); // Reserved 'attribute' field 885349cc55cSDimitry Andric encodeULEB128(Import.SigIndex, W->OS); 8860b57cec5SDimitry Andric break; 8870b57cec5SDimitry Andric default: 8880b57cec5SDimitry Andric llvm_unreachable("unsupported import kind"); 8890b57cec5SDimitry Andric } 8900b57cec5SDimitry Andric } 8910b57cec5SDimitry Andric 8920b57cec5SDimitry Andric endSection(Section); 8930b57cec5SDimitry Andric } 8940b57cec5SDimitry Andric 8950b57cec5SDimitry Andric void WasmObjectWriter::writeFunctionSection(ArrayRef<WasmFunction> Functions) { 8960b57cec5SDimitry Andric if (Functions.empty()) 8970b57cec5SDimitry Andric return; 8980b57cec5SDimitry Andric 8990b57cec5SDimitry Andric SectionBookkeeping Section; 9000b57cec5SDimitry Andric startSection(Section, wasm::WASM_SEC_FUNCTION); 9010b57cec5SDimitry Andric 902e8d8bef9SDimitry Andric encodeULEB128(Functions.size(), W->OS); 9030b57cec5SDimitry Andric for (const WasmFunction &Func : Functions) 904e8d8bef9SDimitry Andric encodeULEB128(Func.SigIndex, W->OS); 9050b57cec5SDimitry Andric 9060b57cec5SDimitry Andric endSection(Section); 9070b57cec5SDimitry Andric } 9080b57cec5SDimitry Andric 909349cc55cSDimitry Andric void WasmObjectWriter::writeTagSection(ArrayRef<uint32_t> TagTypes) { 910349cc55cSDimitry Andric if (TagTypes.empty()) 9110b57cec5SDimitry Andric return; 9120b57cec5SDimitry Andric 9130b57cec5SDimitry Andric SectionBookkeeping Section; 914fe6060f1SDimitry Andric startSection(Section, wasm::WASM_SEC_TAG); 9150b57cec5SDimitry Andric 916349cc55cSDimitry Andric encodeULEB128(TagTypes.size(), W->OS); 917349cc55cSDimitry Andric for (uint32_t Index : TagTypes) { 918349cc55cSDimitry Andric W->OS << char(0); // Reserved 'attribute' field 919349cc55cSDimitry Andric encodeULEB128(Index, W->OS); 9200b57cec5SDimitry Andric } 9210b57cec5SDimitry Andric 9220b57cec5SDimitry Andric endSection(Section); 9230b57cec5SDimitry Andric } 9240b57cec5SDimitry Andric 9255ffd83dbSDimitry Andric void WasmObjectWriter::writeGlobalSection(ArrayRef<wasm::WasmGlobal> Globals) { 9265ffd83dbSDimitry Andric if (Globals.empty()) 9275ffd83dbSDimitry Andric return; 9285ffd83dbSDimitry Andric 9295ffd83dbSDimitry Andric SectionBookkeeping Section; 9305ffd83dbSDimitry Andric startSection(Section, wasm::WASM_SEC_GLOBAL); 9315ffd83dbSDimitry Andric 932e8d8bef9SDimitry Andric encodeULEB128(Globals.size(), W->OS); 9335ffd83dbSDimitry Andric for (const wasm::WasmGlobal &Global : Globals) { 934e8d8bef9SDimitry Andric encodeULEB128(Global.Type.Type, W->OS); 935e8d8bef9SDimitry Andric W->OS << char(Global.Type.Mutable); 93681ad6265SDimitry Andric if (Global.InitExpr.Extended) { 93781ad6265SDimitry Andric llvm_unreachable("extected init expressions not supported"); 93881ad6265SDimitry Andric } else { 93981ad6265SDimitry Andric W->OS << char(Global.InitExpr.Inst.Opcode); 9405ffd83dbSDimitry Andric switch (Global.Type.Type) { 9415ffd83dbSDimitry Andric case wasm::WASM_TYPE_I32: 942e8d8bef9SDimitry Andric encodeSLEB128(0, W->OS); 9435ffd83dbSDimitry Andric break; 9445ffd83dbSDimitry Andric case wasm::WASM_TYPE_I64: 945e8d8bef9SDimitry Andric encodeSLEB128(0, W->OS); 9465ffd83dbSDimitry Andric break; 9475ffd83dbSDimitry Andric case wasm::WASM_TYPE_F32: 9485ffd83dbSDimitry Andric writeI32(0); 9495ffd83dbSDimitry Andric break; 9505ffd83dbSDimitry Andric case wasm::WASM_TYPE_F64: 9515ffd83dbSDimitry Andric writeI64(0); 9525ffd83dbSDimitry Andric break; 9535ffd83dbSDimitry Andric case wasm::WASM_TYPE_EXTERNREF: 9545ffd83dbSDimitry Andric writeValueType(wasm::ValType::EXTERNREF); 9555ffd83dbSDimitry Andric break; 9565ffd83dbSDimitry Andric default: 9575ffd83dbSDimitry Andric llvm_unreachable("unexpected type"); 9585ffd83dbSDimitry Andric } 95981ad6265SDimitry Andric } 960e8d8bef9SDimitry Andric W->OS << char(wasm::WASM_OPCODE_END); 9615ffd83dbSDimitry Andric } 9625ffd83dbSDimitry Andric 9635ffd83dbSDimitry Andric endSection(Section); 9645ffd83dbSDimitry Andric } 9655ffd83dbSDimitry Andric 966e8d8bef9SDimitry Andric void WasmObjectWriter::writeTableSection(ArrayRef<wasm::WasmTable> Tables) { 967e8d8bef9SDimitry Andric if (Tables.empty()) 968e8d8bef9SDimitry Andric return; 969e8d8bef9SDimitry Andric 970e8d8bef9SDimitry Andric SectionBookkeeping Section; 971e8d8bef9SDimitry Andric startSection(Section, wasm::WASM_SEC_TABLE); 972e8d8bef9SDimitry Andric 973e8d8bef9SDimitry Andric encodeULEB128(Tables.size(), W->OS); 974e8d8bef9SDimitry Andric for (const wasm::WasmTable &Table : Tables) { 975e8d8bef9SDimitry Andric encodeULEB128(Table.Type.ElemType, W->OS); 976e8d8bef9SDimitry Andric encodeULEB128(Table.Type.Limits.Flags, W->OS); 977fe6060f1SDimitry Andric encodeULEB128(Table.Type.Limits.Minimum, W->OS); 978e8d8bef9SDimitry Andric if (Table.Type.Limits.Flags & wasm::WASM_LIMITS_FLAG_HAS_MAX) 979e8d8bef9SDimitry Andric encodeULEB128(Table.Type.Limits.Maximum, W->OS); 980e8d8bef9SDimitry Andric } 981e8d8bef9SDimitry Andric endSection(Section); 982e8d8bef9SDimitry Andric } 983e8d8bef9SDimitry Andric 9840b57cec5SDimitry Andric void WasmObjectWriter::writeExportSection(ArrayRef<wasm::WasmExport> Exports) { 9850b57cec5SDimitry Andric if (Exports.empty()) 9860b57cec5SDimitry Andric return; 9870b57cec5SDimitry Andric 9880b57cec5SDimitry Andric SectionBookkeeping Section; 9890b57cec5SDimitry Andric startSection(Section, wasm::WASM_SEC_EXPORT); 9900b57cec5SDimitry Andric 991e8d8bef9SDimitry Andric encodeULEB128(Exports.size(), W->OS); 9920b57cec5SDimitry Andric for (const wasm::WasmExport &Export : Exports) { 9930b57cec5SDimitry Andric writeString(Export.Name); 994e8d8bef9SDimitry Andric W->OS << char(Export.Kind); 995e8d8bef9SDimitry Andric encodeULEB128(Export.Index, W->OS); 9960b57cec5SDimitry Andric } 9970b57cec5SDimitry Andric 9980b57cec5SDimitry Andric endSection(Section); 9990b57cec5SDimitry Andric } 10000b57cec5SDimitry Andric 1001fe6060f1SDimitry Andric void WasmObjectWriter::writeElemSection( 1002fe6060f1SDimitry Andric const MCSymbolWasm *IndirectFunctionTable, ArrayRef<uint32_t> TableElems) { 10030b57cec5SDimitry Andric if (TableElems.empty()) 10040b57cec5SDimitry Andric return; 10050b57cec5SDimitry Andric 1006fe6060f1SDimitry Andric assert(IndirectFunctionTable); 1007fe6060f1SDimitry Andric 10080b57cec5SDimitry Andric SectionBookkeeping Section; 10090b57cec5SDimitry Andric startSection(Section, wasm::WASM_SEC_ELEM); 10100b57cec5SDimitry Andric 1011e8d8bef9SDimitry Andric encodeULEB128(1, W->OS); // number of "segments" 1012fe6060f1SDimitry Andric 1013fe6060f1SDimitry Andric assert(WasmIndices.count(IndirectFunctionTable)); 1014fe6060f1SDimitry Andric uint32_t TableNumber = WasmIndices.find(IndirectFunctionTable)->second; 1015fe6060f1SDimitry Andric uint32_t Flags = 0; 1016fe6060f1SDimitry Andric if (TableNumber) 1017fe6060f1SDimitry Andric Flags |= wasm::WASM_ELEM_SEGMENT_HAS_TABLE_NUMBER; 1018fe6060f1SDimitry Andric encodeULEB128(Flags, W->OS); 1019fe6060f1SDimitry Andric if (Flags & wasm::WASM_ELEM_SEGMENT_HAS_TABLE_NUMBER) 1020fe6060f1SDimitry Andric encodeULEB128(TableNumber, W->OS); // the table number 10210b57cec5SDimitry Andric 10220b57cec5SDimitry Andric // init expr for starting offset 1023e8d8bef9SDimitry Andric W->OS << char(wasm::WASM_OPCODE_I32_CONST); 1024e8d8bef9SDimitry Andric encodeSLEB128(InitialTableOffset, W->OS); 1025e8d8bef9SDimitry Andric W->OS << char(wasm::WASM_OPCODE_END); 10260b57cec5SDimitry Andric 1027fe6060f1SDimitry Andric if (Flags & wasm::WASM_ELEM_SEGMENT_MASK_HAS_ELEM_KIND) { 1028fe6060f1SDimitry Andric // We only write active function table initializers, for which the elem kind 1029fe6060f1SDimitry Andric // is specified to be written as 0x00 and interpreted to mean "funcref". 1030fe6060f1SDimitry Andric const uint8_t ElemKind = 0; 1031fe6060f1SDimitry Andric W->OS << ElemKind; 1032fe6060f1SDimitry Andric } 1033fe6060f1SDimitry Andric 1034e8d8bef9SDimitry Andric encodeULEB128(TableElems.size(), W->OS); 10350b57cec5SDimitry Andric for (uint32_t Elem : TableElems) 1036e8d8bef9SDimitry Andric encodeULEB128(Elem, W->OS); 10370b57cec5SDimitry Andric 10380b57cec5SDimitry Andric endSection(Section); 10390b57cec5SDimitry Andric } 10400b57cec5SDimitry Andric 10410b57cec5SDimitry Andric void WasmObjectWriter::writeDataCountSection() { 10420b57cec5SDimitry Andric if (DataSegments.empty()) 10430b57cec5SDimitry Andric return; 10440b57cec5SDimitry Andric 10450b57cec5SDimitry Andric SectionBookkeeping Section; 10460b57cec5SDimitry Andric startSection(Section, wasm::WASM_SEC_DATACOUNT); 1047e8d8bef9SDimitry Andric encodeULEB128(DataSegments.size(), W->OS); 10480b57cec5SDimitry Andric endSection(Section); 10490b57cec5SDimitry Andric } 10500b57cec5SDimitry Andric 10515ffd83dbSDimitry Andric uint32_t WasmObjectWriter::writeCodeSection(const MCAssembler &Asm, 10520b57cec5SDimitry Andric const MCAsmLayout &Layout, 10530b57cec5SDimitry Andric ArrayRef<WasmFunction> Functions) { 10540b57cec5SDimitry Andric if (Functions.empty()) 10555ffd83dbSDimitry Andric return 0; 10560b57cec5SDimitry Andric 10570b57cec5SDimitry Andric SectionBookkeeping Section; 10580b57cec5SDimitry Andric startSection(Section, wasm::WASM_SEC_CODE); 10590b57cec5SDimitry Andric 1060e8d8bef9SDimitry Andric encodeULEB128(Functions.size(), W->OS); 10610b57cec5SDimitry Andric 10620b57cec5SDimitry Andric for (const WasmFunction &Func : Functions) { 1063bdd1243dSDimitry Andric auto *FuncSection = static_cast<MCSectionWasm *>(Func.Section); 10640b57cec5SDimitry Andric 1065bdd1243dSDimitry Andric int64_t Size = Layout.getSectionAddressSize(FuncSection); 1066e8d8bef9SDimitry Andric encodeULEB128(Size, W->OS); 1067bdd1243dSDimitry Andric FuncSection->setSectionOffset(W->OS.tell() - Section.ContentsOffset); 1068bdd1243dSDimitry Andric Asm.writeSectionData(W->OS, FuncSection, Layout); 10690b57cec5SDimitry Andric } 10700b57cec5SDimitry Andric 10710b57cec5SDimitry Andric // Apply fixups. 10725ffd83dbSDimitry Andric applyRelocations(CodeRelocations, Section.ContentsOffset, Layout); 10730b57cec5SDimitry Andric 10740b57cec5SDimitry Andric endSection(Section); 10755ffd83dbSDimitry Andric return Section.Index; 10760b57cec5SDimitry Andric } 10770b57cec5SDimitry Andric 10785ffd83dbSDimitry Andric uint32_t WasmObjectWriter::writeDataSection(const MCAsmLayout &Layout) { 10790b57cec5SDimitry Andric if (DataSegments.empty()) 10805ffd83dbSDimitry Andric return 0; 10810b57cec5SDimitry Andric 10820b57cec5SDimitry Andric SectionBookkeeping Section; 10830b57cec5SDimitry Andric startSection(Section, wasm::WASM_SEC_DATA); 10840b57cec5SDimitry Andric 1085e8d8bef9SDimitry Andric encodeULEB128(DataSegments.size(), W->OS); // count 10860b57cec5SDimitry Andric 10870b57cec5SDimitry Andric for (const WasmDataSegment &Segment : DataSegments) { 1088e8d8bef9SDimitry Andric encodeULEB128(Segment.InitFlags, W->OS); // flags 1089e8d8bef9SDimitry Andric if (Segment.InitFlags & wasm::WASM_DATA_SEGMENT_HAS_MEMINDEX) 1090e8d8bef9SDimitry Andric encodeULEB128(0, W->OS); // memory index 1091e8d8bef9SDimitry Andric if ((Segment.InitFlags & wasm::WASM_DATA_SEGMENT_IS_PASSIVE) == 0) { 1092fe6060f1SDimitry Andric W->OS << char(is64Bit() ? wasm::WASM_OPCODE_I64_CONST 10935ffd83dbSDimitry Andric : wasm::WASM_OPCODE_I32_CONST); 1094e8d8bef9SDimitry Andric encodeSLEB128(Segment.Offset, W->OS); // offset 1095e8d8bef9SDimitry Andric W->OS << char(wasm::WASM_OPCODE_END); 10960b57cec5SDimitry Andric } 1097e8d8bef9SDimitry Andric encodeULEB128(Segment.Data.size(), W->OS); // size 1098e8d8bef9SDimitry Andric Segment.Section->setSectionOffset(W->OS.tell() - Section.ContentsOffset); 1099e8d8bef9SDimitry Andric W->OS << Segment.Data; // data 11000b57cec5SDimitry Andric } 11010b57cec5SDimitry Andric 11020b57cec5SDimitry Andric // Apply fixups. 11035ffd83dbSDimitry Andric applyRelocations(DataRelocations, Section.ContentsOffset, Layout); 11040b57cec5SDimitry Andric 11050b57cec5SDimitry Andric endSection(Section); 11065ffd83dbSDimitry Andric return Section.Index; 11070b57cec5SDimitry Andric } 11080b57cec5SDimitry Andric 11090b57cec5SDimitry Andric void WasmObjectWriter::writeRelocSection( 11100b57cec5SDimitry Andric uint32_t SectionIndex, StringRef Name, 11110b57cec5SDimitry Andric std::vector<WasmRelocationEntry> &Relocs) { 1112349cc55cSDimitry Andric // See: https://github.com/WebAssembly/tool-conventions/blob/main/Linking.md 11130b57cec5SDimitry Andric // for descriptions of the reloc sections. 11140b57cec5SDimitry Andric 11150b57cec5SDimitry Andric if (Relocs.empty()) 11160b57cec5SDimitry Andric return; 11170b57cec5SDimitry Andric 11180b57cec5SDimitry Andric // First, ensure the relocations are sorted in offset order. In general they 11190b57cec5SDimitry Andric // should already be sorted since `recordRelocation` is called in offset 11200b57cec5SDimitry Andric // order, but for the code section we combine many MC sections into single 11210b57cec5SDimitry Andric // wasm section, and this order is determined by the order of Asm.Symbols() 11220b57cec5SDimitry Andric // not the sections order. 11230b57cec5SDimitry Andric llvm::stable_sort( 11240b57cec5SDimitry Andric Relocs, [](const WasmRelocationEntry &A, const WasmRelocationEntry &B) { 11250b57cec5SDimitry Andric return (A.Offset + A.FixupSection->getSectionOffset()) < 11260b57cec5SDimitry Andric (B.Offset + B.FixupSection->getSectionOffset()); 11270b57cec5SDimitry Andric }); 11280b57cec5SDimitry Andric 11290b57cec5SDimitry Andric SectionBookkeeping Section; 11300b57cec5SDimitry Andric startCustomSection(Section, std::string("reloc.") + Name.str()); 11310b57cec5SDimitry Andric 1132e8d8bef9SDimitry Andric encodeULEB128(SectionIndex, W->OS); 1133e8d8bef9SDimitry Andric encodeULEB128(Relocs.size(), W->OS); 11340b57cec5SDimitry Andric for (const WasmRelocationEntry &RelEntry : Relocs) { 11350b57cec5SDimitry Andric uint64_t Offset = 11360b57cec5SDimitry Andric RelEntry.Offset + RelEntry.FixupSection->getSectionOffset(); 11370b57cec5SDimitry Andric uint32_t Index = getRelocationIndexValue(RelEntry); 11380b57cec5SDimitry Andric 1139e8d8bef9SDimitry Andric W->OS << char(RelEntry.Type); 1140e8d8bef9SDimitry Andric encodeULEB128(Offset, W->OS); 1141e8d8bef9SDimitry Andric encodeULEB128(Index, W->OS); 11420b57cec5SDimitry Andric if (RelEntry.hasAddend()) 1143e8d8bef9SDimitry Andric encodeSLEB128(RelEntry.Addend, W->OS); 11440b57cec5SDimitry Andric } 11450b57cec5SDimitry Andric 11460b57cec5SDimitry Andric endSection(Section); 11470b57cec5SDimitry Andric } 11480b57cec5SDimitry Andric 11490b57cec5SDimitry Andric void WasmObjectWriter::writeCustomRelocSections() { 11500b57cec5SDimitry Andric for (const auto &Sec : CustomSections) { 11510b57cec5SDimitry Andric auto &Relocations = CustomSectionsRelocations[Sec.Section]; 11520b57cec5SDimitry Andric writeRelocSection(Sec.OutputIndex, Sec.Name, Relocations); 11530b57cec5SDimitry Andric } 11540b57cec5SDimitry Andric } 11550b57cec5SDimitry Andric 11560b57cec5SDimitry Andric void WasmObjectWriter::writeLinkingMetaDataSection( 11570b57cec5SDimitry Andric ArrayRef<wasm::WasmSymbolInfo> SymbolInfos, 11580b57cec5SDimitry Andric ArrayRef<std::pair<uint16_t, uint32_t>> InitFuncs, 11590b57cec5SDimitry Andric const std::map<StringRef, std::vector<WasmComdatEntry>> &Comdats) { 11600b57cec5SDimitry Andric SectionBookkeeping Section; 11610b57cec5SDimitry Andric startCustomSection(Section, "linking"); 1162e8d8bef9SDimitry Andric encodeULEB128(wasm::WasmMetadataVersion, W->OS); 11630b57cec5SDimitry Andric 11640b57cec5SDimitry Andric SectionBookkeeping SubSection; 11650b57cec5SDimitry Andric if (SymbolInfos.size() != 0) { 11660b57cec5SDimitry Andric startSection(SubSection, wasm::WASM_SYMBOL_TABLE); 1167e8d8bef9SDimitry Andric encodeULEB128(SymbolInfos.size(), W->OS); 11680b57cec5SDimitry Andric for (const wasm::WasmSymbolInfo &Sym : SymbolInfos) { 1169e8d8bef9SDimitry Andric encodeULEB128(Sym.Kind, W->OS); 1170e8d8bef9SDimitry Andric encodeULEB128(Sym.Flags, W->OS); 11710b57cec5SDimitry Andric switch (Sym.Kind) { 11720b57cec5SDimitry Andric case wasm::WASM_SYMBOL_TYPE_FUNCTION: 11730b57cec5SDimitry Andric case wasm::WASM_SYMBOL_TYPE_GLOBAL: 1174fe6060f1SDimitry Andric case wasm::WASM_SYMBOL_TYPE_TAG: 1175e8d8bef9SDimitry Andric case wasm::WASM_SYMBOL_TYPE_TABLE: 1176e8d8bef9SDimitry Andric encodeULEB128(Sym.ElementIndex, W->OS); 11770b57cec5SDimitry Andric if ((Sym.Flags & wasm::WASM_SYMBOL_UNDEFINED) == 0 || 11780b57cec5SDimitry Andric (Sym.Flags & wasm::WASM_SYMBOL_EXPLICIT_NAME) != 0) 11790b57cec5SDimitry Andric writeString(Sym.Name); 11800b57cec5SDimitry Andric break; 11810b57cec5SDimitry Andric case wasm::WASM_SYMBOL_TYPE_DATA: 11820b57cec5SDimitry Andric writeString(Sym.Name); 11830b57cec5SDimitry Andric if ((Sym.Flags & wasm::WASM_SYMBOL_UNDEFINED) == 0) { 1184e8d8bef9SDimitry Andric encodeULEB128(Sym.DataRef.Segment, W->OS); 1185e8d8bef9SDimitry Andric encodeULEB128(Sym.DataRef.Offset, W->OS); 1186e8d8bef9SDimitry Andric encodeULEB128(Sym.DataRef.Size, W->OS); 11870b57cec5SDimitry Andric } 11880b57cec5SDimitry Andric break; 11890b57cec5SDimitry Andric case wasm::WASM_SYMBOL_TYPE_SECTION: { 11900b57cec5SDimitry Andric const uint32_t SectionIndex = 11910b57cec5SDimitry Andric CustomSections[Sym.ElementIndex].OutputIndex; 1192e8d8bef9SDimitry Andric encodeULEB128(SectionIndex, W->OS); 11930b57cec5SDimitry Andric break; 11940b57cec5SDimitry Andric } 11950b57cec5SDimitry Andric default: 11960b57cec5SDimitry Andric llvm_unreachable("unexpected kind"); 11970b57cec5SDimitry Andric } 11980b57cec5SDimitry Andric } 11990b57cec5SDimitry Andric endSection(SubSection); 12000b57cec5SDimitry Andric } 12010b57cec5SDimitry Andric 12020b57cec5SDimitry Andric if (DataSegments.size()) { 12030b57cec5SDimitry Andric startSection(SubSection, wasm::WASM_SEGMENT_INFO); 1204e8d8bef9SDimitry Andric encodeULEB128(DataSegments.size(), W->OS); 12050b57cec5SDimitry Andric for (const WasmDataSegment &Segment : DataSegments) { 12060b57cec5SDimitry Andric writeString(Segment.Name); 1207e8d8bef9SDimitry Andric encodeULEB128(Segment.Alignment, W->OS); 1208fe6060f1SDimitry Andric encodeULEB128(Segment.LinkingFlags, W->OS); 12090b57cec5SDimitry Andric } 12100b57cec5SDimitry Andric endSection(SubSection); 12110b57cec5SDimitry Andric } 12120b57cec5SDimitry Andric 12130b57cec5SDimitry Andric if (!InitFuncs.empty()) { 12140b57cec5SDimitry Andric startSection(SubSection, wasm::WASM_INIT_FUNCS); 1215e8d8bef9SDimitry Andric encodeULEB128(InitFuncs.size(), W->OS); 12160b57cec5SDimitry Andric for (auto &StartFunc : InitFuncs) { 1217e8d8bef9SDimitry Andric encodeULEB128(StartFunc.first, W->OS); // priority 1218e8d8bef9SDimitry Andric encodeULEB128(StartFunc.second, W->OS); // function index 12190b57cec5SDimitry Andric } 12200b57cec5SDimitry Andric endSection(SubSection); 12210b57cec5SDimitry Andric } 12220b57cec5SDimitry Andric 12230b57cec5SDimitry Andric if (Comdats.size()) { 12240b57cec5SDimitry Andric startSection(SubSection, wasm::WASM_COMDAT_INFO); 1225e8d8bef9SDimitry Andric encodeULEB128(Comdats.size(), W->OS); 12260b57cec5SDimitry Andric for (const auto &C : Comdats) { 12270b57cec5SDimitry Andric writeString(C.first); 1228e8d8bef9SDimitry Andric encodeULEB128(0, W->OS); // flags for future use 1229e8d8bef9SDimitry Andric encodeULEB128(C.second.size(), W->OS); 12300b57cec5SDimitry Andric for (const WasmComdatEntry &Entry : C.second) { 1231e8d8bef9SDimitry Andric encodeULEB128(Entry.Kind, W->OS); 1232e8d8bef9SDimitry Andric encodeULEB128(Entry.Index, W->OS); 12330b57cec5SDimitry Andric } 12340b57cec5SDimitry Andric } 12350b57cec5SDimitry Andric endSection(SubSection); 12360b57cec5SDimitry Andric } 12370b57cec5SDimitry Andric 12380b57cec5SDimitry Andric endSection(Section); 12390b57cec5SDimitry Andric } 12400b57cec5SDimitry Andric 12410b57cec5SDimitry Andric void WasmObjectWriter::writeCustomSection(WasmCustomSection &CustomSection, 12420b57cec5SDimitry Andric const MCAssembler &Asm, 12430b57cec5SDimitry Andric const MCAsmLayout &Layout) { 12440b57cec5SDimitry Andric SectionBookkeeping Section; 12450b57cec5SDimitry Andric auto *Sec = CustomSection.Section; 12460b57cec5SDimitry Andric startCustomSection(Section, CustomSection.Name); 12470b57cec5SDimitry Andric 1248e8d8bef9SDimitry Andric Sec->setSectionOffset(W->OS.tell() - Section.ContentsOffset); 1249e8d8bef9SDimitry Andric Asm.writeSectionData(W->OS, Sec, Layout); 12500b57cec5SDimitry Andric 12510b57cec5SDimitry Andric CustomSection.OutputContentsOffset = Section.ContentsOffset; 12520b57cec5SDimitry Andric CustomSection.OutputIndex = Section.Index; 12530b57cec5SDimitry Andric 12540b57cec5SDimitry Andric endSection(Section); 12550b57cec5SDimitry Andric 12560b57cec5SDimitry Andric // Apply fixups. 12570b57cec5SDimitry Andric auto &Relocations = CustomSectionsRelocations[CustomSection.Section]; 12585ffd83dbSDimitry Andric applyRelocations(Relocations, CustomSection.OutputContentsOffset, Layout); 12590b57cec5SDimitry Andric } 12600b57cec5SDimitry Andric 12610b57cec5SDimitry Andric uint32_t WasmObjectWriter::getFunctionType(const MCSymbolWasm &Symbol) { 12620b57cec5SDimitry Andric assert(Symbol.isFunction()); 12630b57cec5SDimitry Andric assert(TypeIndices.count(&Symbol)); 12640b57cec5SDimitry Andric return TypeIndices[&Symbol]; 12650b57cec5SDimitry Andric } 12660b57cec5SDimitry Andric 1267fe6060f1SDimitry Andric uint32_t WasmObjectWriter::getTagType(const MCSymbolWasm &Symbol) { 1268fe6060f1SDimitry Andric assert(Symbol.isTag()); 12690b57cec5SDimitry Andric assert(TypeIndices.count(&Symbol)); 12700b57cec5SDimitry Andric return TypeIndices[&Symbol]; 12710b57cec5SDimitry Andric } 12720b57cec5SDimitry Andric 12730b57cec5SDimitry Andric void WasmObjectWriter::registerFunctionType(const MCSymbolWasm &Symbol) { 12740b57cec5SDimitry Andric assert(Symbol.isFunction()); 12750b57cec5SDimitry Andric 1276e8d8bef9SDimitry Andric wasm::WasmSignature S; 12775ffd83dbSDimitry Andric 12785ffd83dbSDimitry Andric if (auto *Sig = Symbol.getSignature()) { 12790b57cec5SDimitry Andric S.Returns = Sig->Returns; 12800b57cec5SDimitry Andric S.Params = Sig->Params; 12810b57cec5SDimitry Andric } 12820b57cec5SDimitry Andric 12830b57cec5SDimitry Andric auto Pair = SignatureIndices.insert(std::make_pair(S, Signatures.size())); 12840b57cec5SDimitry Andric if (Pair.second) 12850b57cec5SDimitry Andric Signatures.push_back(S); 12860b57cec5SDimitry Andric TypeIndices[&Symbol] = Pair.first->second; 12870b57cec5SDimitry Andric 12880b57cec5SDimitry Andric LLVM_DEBUG(dbgs() << "registerFunctionType: " << Symbol 12890b57cec5SDimitry Andric << " new:" << Pair.second << "\n"); 12900b57cec5SDimitry Andric LLVM_DEBUG(dbgs() << " -> type index: " << Pair.first->second << "\n"); 12910b57cec5SDimitry Andric } 12920b57cec5SDimitry Andric 1293fe6060f1SDimitry Andric void WasmObjectWriter::registerTagType(const MCSymbolWasm &Symbol) { 1294fe6060f1SDimitry Andric assert(Symbol.isTag()); 12950b57cec5SDimitry Andric 12960b57cec5SDimitry Andric // TODO Currently we don't generate imported exceptions, but if we do, we 12970b57cec5SDimitry Andric // should have a way of infering types of imported exceptions. 1298e8d8bef9SDimitry Andric wasm::WasmSignature S; 12990b57cec5SDimitry Andric if (auto *Sig = Symbol.getSignature()) { 13000b57cec5SDimitry Andric S.Returns = Sig->Returns; 13010b57cec5SDimitry Andric S.Params = Sig->Params; 13020b57cec5SDimitry Andric } 13030b57cec5SDimitry Andric 13040b57cec5SDimitry Andric auto Pair = SignatureIndices.insert(std::make_pair(S, Signatures.size())); 13050b57cec5SDimitry Andric if (Pair.second) 13060b57cec5SDimitry Andric Signatures.push_back(S); 13070b57cec5SDimitry Andric TypeIndices[&Symbol] = Pair.first->second; 13080b57cec5SDimitry Andric 1309fe6060f1SDimitry Andric LLVM_DEBUG(dbgs() << "registerTagType: " << Symbol << " new:" << Pair.second 13100b57cec5SDimitry Andric << "\n"); 13110b57cec5SDimitry Andric LLVM_DEBUG(dbgs() << " -> type index: " << Pair.first->second << "\n"); 13120b57cec5SDimitry Andric } 13130b57cec5SDimitry Andric 13140b57cec5SDimitry Andric static bool isInSymtab(const MCSymbolWasm &Sym) { 13155ffd83dbSDimitry Andric if (Sym.isUsedInReloc() || Sym.isUsedInInitArray()) 13160b57cec5SDimitry Andric return true; 13170b57cec5SDimitry Andric 13180b57cec5SDimitry Andric if (Sym.isComdat() && !Sym.isDefined()) 13190b57cec5SDimitry Andric return false; 13200b57cec5SDimitry Andric 13215ffd83dbSDimitry Andric if (Sym.isTemporary()) 13220b57cec5SDimitry Andric return false; 13230b57cec5SDimitry Andric 13240b57cec5SDimitry Andric if (Sym.isSection()) 13250b57cec5SDimitry Andric return false; 13260b57cec5SDimitry Andric 1327fe6060f1SDimitry Andric if (Sym.omitFromLinkingSection()) 1328fe6060f1SDimitry Andric return false; 1329fe6060f1SDimitry Andric 13300b57cec5SDimitry Andric return true; 13310b57cec5SDimitry Andric } 13320b57cec5SDimitry Andric 1333e8d8bef9SDimitry Andric void WasmObjectWriter::prepareImports( 1334e8d8bef9SDimitry Andric SmallVectorImpl<wasm::WasmImport> &Imports, MCAssembler &Asm, 13350b57cec5SDimitry Andric const MCAsmLayout &Layout) { 13360b57cec5SDimitry Andric // For now, always emit the memory import, since loads and stores are not 13370b57cec5SDimitry Andric // valid without it. In the future, we could perhaps be more clever and omit 13380b57cec5SDimitry Andric // it if there are no loads or stores. 13390b57cec5SDimitry Andric wasm::WasmImport MemImport; 13400b57cec5SDimitry Andric MemImport.Module = "env"; 13410b57cec5SDimitry Andric MemImport.Field = "__linear_memory"; 13420b57cec5SDimitry Andric MemImport.Kind = wasm::WASM_EXTERNAL_MEMORY; 13435ffd83dbSDimitry Andric MemImport.Memory.Flags = is64Bit() ? wasm::WASM_LIMITS_FLAG_IS_64 13445ffd83dbSDimitry Andric : wasm::WASM_LIMITS_FLAG_NONE; 13450b57cec5SDimitry Andric Imports.push_back(MemImport); 13460b57cec5SDimitry Andric 13470b57cec5SDimitry Andric // Populate SignatureIndices, and Imports and WasmIndices for undefined 13480b57cec5SDimitry Andric // symbols. This must be done before populating WasmIndices for defined 13490b57cec5SDimitry Andric // symbols. 13500b57cec5SDimitry Andric for (const MCSymbol &S : Asm.symbols()) { 13510b57cec5SDimitry Andric const auto &WS = static_cast<const MCSymbolWasm &>(S); 13520b57cec5SDimitry Andric 13530b57cec5SDimitry Andric // Register types for all functions, including those with private linkage 13540b57cec5SDimitry Andric // (because wasm always needs a type signature). 13555ffd83dbSDimitry Andric if (WS.isFunction()) { 1356e8d8bef9SDimitry Andric const auto *BS = Layout.getBaseSymbol(S); 1357e8d8bef9SDimitry Andric if (!BS) 1358e8d8bef9SDimitry Andric report_fatal_error(Twine(S.getName()) + 1359e8d8bef9SDimitry Andric ": absolute addressing not supported!"); 1360e8d8bef9SDimitry Andric registerFunctionType(*cast<MCSymbolWasm>(BS)); 13615ffd83dbSDimitry Andric } 13620b57cec5SDimitry Andric 1363fe6060f1SDimitry Andric if (WS.isTag()) 1364fe6060f1SDimitry Andric registerTagType(WS); 13650b57cec5SDimitry Andric 13660b57cec5SDimitry Andric if (WS.isTemporary()) 13670b57cec5SDimitry Andric continue; 13680b57cec5SDimitry Andric 13690b57cec5SDimitry Andric // If the symbol is not defined in this translation unit, import it. 13700b57cec5SDimitry Andric if (!WS.isDefined() && !WS.isComdat()) { 13710b57cec5SDimitry Andric if (WS.isFunction()) { 13720b57cec5SDimitry Andric wasm::WasmImport Import; 13730b57cec5SDimitry Andric Import.Module = WS.getImportModule(); 13740b57cec5SDimitry Andric Import.Field = WS.getImportName(); 13750b57cec5SDimitry Andric Import.Kind = wasm::WASM_EXTERNAL_FUNCTION; 13760b57cec5SDimitry Andric Import.SigIndex = getFunctionType(WS); 13770b57cec5SDimitry Andric Imports.push_back(Import); 13780b57cec5SDimitry Andric assert(WasmIndices.count(&WS) == 0); 13790b57cec5SDimitry Andric WasmIndices[&WS] = NumFunctionImports++; 13800b57cec5SDimitry Andric } else if (WS.isGlobal()) { 13810b57cec5SDimitry Andric if (WS.isWeak()) 13820b57cec5SDimitry Andric report_fatal_error("undefined global symbol cannot be weak"); 13830b57cec5SDimitry Andric 13840b57cec5SDimitry Andric wasm::WasmImport Import; 13850b57cec5SDimitry Andric Import.Field = WS.getImportName(); 13860b57cec5SDimitry Andric Import.Kind = wasm::WASM_EXTERNAL_GLOBAL; 13870b57cec5SDimitry Andric Import.Module = WS.getImportModule(); 13880b57cec5SDimitry Andric Import.Global = WS.getGlobalType(); 13890b57cec5SDimitry Andric Imports.push_back(Import); 13900b57cec5SDimitry Andric assert(WasmIndices.count(&WS) == 0); 13910b57cec5SDimitry Andric WasmIndices[&WS] = NumGlobalImports++; 1392fe6060f1SDimitry Andric } else if (WS.isTag()) { 13930b57cec5SDimitry Andric if (WS.isWeak()) 1394fe6060f1SDimitry Andric report_fatal_error("undefined tag symbol cannot be weak"); 13950b57cec5SDimitry Andric 13960b57cec5SDimitry Andric wasm::WasmImport Import; 13970b57cec5SDimitry Andric Import.Module = WS.getImportModule(); 13980b57cec5SDimitry Andric Import.Field = WS.getImportName(); 1399fe6060f1SDimitry Andric Import.Kind = wasm::WASM_EXTERNAL_TAG; 1400349cc55cSDimitry Andric Import.SigIndex = getTagType(WS); 14010b57cec5SDimitry Andric Imports.push_back(Import); 14020b57cec5SDimitry Andric assert(WasmIndices.count(&WS) == 0); 1403fe6060f1SDimitry Andric WasmIndices[&WS] = NumTagImports++; 1404e8d8bef9SDimitry Andric } else if (WS.isTable()) { 1405e8d8bef9SDimitry Andric if (WS.isWeak()) 1406e8d8bef9SDimitry Andric report_fatal_error("undefined table symbol cannot be weak"); 1407e8d8bef9SDimitry Andric 1408e8d8bef9SDimitry Andric wasm::WasmImport Import; 1409e8d8bef9SDimitry Andric Import.Module = WS.getImportModule(); 1410e8d8bef9SDimitry Andric Import.Field = WS.getImportName(); 1411e8d8bef9SDimitry Andric Import.Kind = wasm::WASM_EXTERNAL_TABLE; 1412fe6060f1SDimitry Andric Import.Table = WS.getTableType(); 1413e8d8bef9SDimitry Andric Imports.push_back(Import); 1414e8d8bef9SDimitry Andric assert(WasmIndices.count(&WS) == 0); 1415e8d8bef9SDimitry Andric WasmIndices[&WS] = NumTableImports++; 14160b57cec5SDimitry Andric } 14170b57cec5SDimitry Andric } 14180b57cec5SDimitry Andric } 14190b57cec5SDimitry Andric 14200b57cec5SDimitry Andric // Add imports for GOT globals 14210b57cec5SDimitry Andric for (const MCSymbol &S : Asm.symbols()) { 14220b57cec5SDimitry Andric const auto &WS = static_cast<const MCSymbolWasm &>(S); 14230b57cec5SDimitry Andric if (WS.isUsedInGOT()) { 14240b57cec5SDimitry Andric wasm::WasmImport Import; 14250b57cec5SDimitry Andric if (WS.isFunction()) 14260b57cec5SDimitry Andric Import.Module = "GOT.func"; 14270b57cec5SDimitry Andric else 14280b57cec5SDimitry Andric Import.Module = "GOT.mem"; 14290b57cec5SDimitry Andric Import.Field = WS.getName(); 14300b57cec5SDimitry Andric Import.Kind = wasm::WASM_EXTERNAL_GLOBAL; 14310b57cec5SDimitry Andric Import.Global = {wasm::WASM_TYPE_I32, true}; 14320b57cec5SDimitry Andric Imports.push_back(Import); 14330b57cec5SDimitry Andric assert(GOTIndices.count(&WS) == 0); 14340b57cec5SDimitry Andric GOTIndices[&WS] = NumGlobalImports++; 14350b57cec5SDimitry Andric } 14360b57cec5SDimitry Andric } 1437e8d8bef9SDimitry Andric } 1438e8d8bef9SDimitry Andric 1439e8d8bef9SDimitry Andric uint64_t WasmObjectWriter::writeObject(MCAssembler &Asm, 1440e8d8bef9SDimitry Andric const MCAsmLayout &Layout) { 14415f757f3fSDimitry Andric support::endian::Writer MainWriter(*OS, llvm::endianness::little); 1442e8d8bef9SDimitry Andric W = &MainWriter; 1443e8d8bef9SDimitry Andric if (IsSplitDwarf) { 1444e8d8bef9SDimitry Andric uint64_t TotalSize = writeOneObject(Asm, Layout, DwoMode::NonDwoOnly); 1445e8d8bef9SDimitry Andric assert(DwoOS); 14465f757f3fSDimitry Andric support::endian::Writer DwoWriter(*DwoOS, llvm::endianness::little); 1447e8d8bef9SDimitry Andric W = &DwoWriter; 1448e8d8bef9SDimitry Andric return TotalSize + writeOneObject(Asm, Layout, DwoMode::DwoOnly); 1449e8d8bef9SDimitry Andric } else { 1450e8d8bef9SDimitry Andric return writeOneObject(Asm, Layout, DwoMode::AllSections); 1451e8d8bef9SDimitry Andric } 1452e8d8bef9SDimitry Andric } 1453e8d8bef9SDimitry Andric 1454e8d8bef9SDimitry Andric uint64_t WasmObjectWriter::writeOneObject(MCAssembler &Asm, 1455e8d8bef9SDimitry Andric const MCAsmLayout &Layout, 1456e8d8bef9SDimitry Andric DwoMode Mode) { 1457e8d8bef9SDimitry Andric uint64_t StartOffset = W->OS.tell(); 1458e8d8bef9SDimitry Andric SectionCount = 0; 1459e8d8bef9SDimitry Andric CustomSections.clear(); 1460e8d8bef9SDimitry Andric 1461e8d8bef9SDimitry Andric LLVM_DEBUG(dbgs() << "WasmObjectWriter::writeObject\n"); 1462e8d8bef9SDimitry Andric 1463e8d8bef9SDimitry Andric // Collect information from the available symbols. 1464e8d8bef9SDimitry Andric SmallVector<WasmFunction, 4> Functions; 1465e8d8bef9SDimitry Andric SmallVector<uint32_t, 4> TableElems; 1466e8d8bef9SDimitry Andric SmallVector<wasm::WasmImport, 4> Imports; 1467e8d8bef9SDimitry Andric SmallVector<wasm::WasmExport, 4> Exports; 1468349cc55cSDimitry Andric SmallVector<uint32_t, 2> TagTypes; 1469e8d8bef9SDimitry Andric SmallVector<wasm::WasmGlobal, 1> Globals; 1470e8d8bef9SDimitry Andric SmallVector<wasm::WasmTable, 1> Tables; 1471e8d8bef9SDimitry Andric SmallVector<wasm::WasmSymbolInfo, 4> SymbolInfos; 1472e8d8bef9SDimitry Andric SmallVector<std::pair<uint16_t, uint32_t>, 2> InitFuncs; 1473e8d8bef9SDimitry Andric std::map<StringRef, std::vector<WasmComdatEntry>> Comdats; 1474e8d8bef9SDimitry Andric uint64_t DataSize = 0; 1475e8d8bef9SDimitry Andric if (Mode != DwoMode::DwoOnly) { 1476e8d8bef9SDimitry Andric prepareImports(Imports, Asm, Layout); 1477e8d8bef9SDimitry Andric } 14780b57cec5SDimitry Andric 14790b57cec5SDimitry Andric // Populate DataSegments and CustomSections, which must be done before 14800b57cec5SDimitry Andric // populating DataLocations. 14810b57cec5SDimitry Andric for (MCSection &Sec : Asm) { 14820b57cec5SDimitry Andric auto &Section = static_cast<MCSectionWasm &>(Sec); 14835ffd83dbSDimitry Andric StringRef SectionName = Section.getName(); 14840b57cec5SDimitry Andric 1485e8d8bef9SDimitry Andric if (Mode == DwoMode::NonDwoOnly && isDwoSection(Sec)) 1486e8d8bef9SDimitry Andric continue; 1487e8d8bef9SDimitry Andric if (Mode == DwoMode::DwoOnly && !isDwoSection(Sec)) 1488e8d8bef9SDimitry Andric continue; 1489e8d8bef9SDimitry Andric 1490e8d8bef9SDimitry Andric LLVM_DEBUG(dbgs() << "Processing Section " << SectionName << " group " 1491e8d8bef9SDimitry Andric << Section.getGroup() << "\n";); 1492e8d8bef9SDimitry Andric 14930b57cec5SDimitry Andric // .init_array sections are handled specially elsewhere. 14945f757f3fSDimitry Andric if (SectionName.starts_with(".init_array")) 14950b57cec5SDimitry Andric continue; 14960b57cec5SDimitry Andric 14970b57cec5SDimitry Andric // Code is handled separately 14980b57cec5SDimitry Andric if (Section.getKind().isText()) 14990b57cec5SDimitry Andric continue; 15000b57cec5SDimitry Andric 15010b57cec5SDimitry Andric if (Section.isWasmData()) { 15020b57cec5SDimitry Andric uint32_t SegmentIndex = DataSegments.size(); 1503bdd1243dSDimitry Andric DataSize = alignTo(DataSize, Section.getAlign()); 15040b57cec5SDimitry Andric DataSegments.emplace_back(); 15050b57cec5SDimitry Andric WasmDataSegment &Segment = DataSegments.back(); 15060b57cec5SDimitry Andric Segment.Name = SectionName; 1507e8d8bef9SDimitry Andric Segment.InitFlags = Section.getPassive() 1508e8d8bef9SDimitry Andric ? (uint32_t)wasm::WASM_DATA_SEGMENT_IS_PASSIVE 1509e8d8bef9SDimitry Andric : 0; 15100b57cec5SDimitry Andric Segment.Offset = DataSize; 15110b57cec5SDimitry Andric Segment.Section = &Section; 15120b57cec5SDimitry Andric addData(Segment.Data, Section); 1513bdd1243dSDimitry Andric Segment.Alignment = Log2(Section.getAlign()); 1514fe6060f1SDimitry Andric Segment.LinkingFlags = Section.getSegmentFlags(); 15150b57cec5SDimitry Andric DataSize += Segment.Data.size(); 15160b57cec5SDimitry Andric Section.setSegmentIndex(SegmentIndex); 15170b57cec5SDimitry Andric 15180b57cec5SDimitry Andric if (const MCSymbolWasm *C = Section.getGroup()) { 15190b57cec5SDimitry Andric Comdats[C->getName()].emplace_back( 15200b57cec5SDimitry Andric WasmComdatEntry{wasm::WASM_COMDAT_DATA, SegmentIndex}); 15210b57cec5SDimitry Andric } 15220b57cec5SDimitry Andric } else { 15230b57cec5SDimitry Andric // Create custom sections 15240b57cec5SDimitry Andric assert(Sec.getKind().isMetadata()); 15250b57cec5SDimitry Andric 15260b57cec5SDimitry Andric StringRef Name = SectionName; 15270b57cec5SDimitry Andric 15280b57cec5SDimitry Andric // For user-defined custom sections, strip the prefix 1529647cbc5dSDimitry Andric Name.consume_front(".custom_section."); 15300b57cec5SDimitry Andric 15310b57cec5SDimitry Andric MCSymbol *Begin = Sec.getBeginSymbol(); 15320b57cec5SDimitry Andric if (Begin) { 1533e8d8bef9SDimitry Andric assert(WasmIndices.count(cast<MCSymbolWasm>(Begin)) == 0); 15340b57cec5SDimitry Andric WasmIndices[cast<MCSymbolWasm>(Begin)] = CustomSections.size(); 15350b57cec5SDimitry Andric } 15360b57cec5SDimitry Andric 15370b57cec5SDimitry Andric // Separate out the producers and target features sections 15380b57cec5SDimitry Andric if (Name == "producers") { 15398bcb0991SDimitry Andric ProducersSection = std::make_unique<WasmCustomSection>(Name, &Section); 15400b57cec5SDimitry Andric continue; 15410b57cec5SDimitry Andric } 15420b57cec5SDimitry Andric if (Name == "target_features") { 15430b57cec5SDimitry Andric TargetFeaturesSection = 15448bcb0991SDimitry Andric std::make_unique<WasmCustomSection>(Name, &Section); 15450b57cec5SDimitry Andric continue; 15460b57cec5SDimitry Andric } 15470b57cec5SDimitry Andric 1548e8d8bef9SDimitry Andric // Custom sections can also belong to COMDAT groups. In this case the 1549e8d8bef9SDimitry Andric // decriptor's "index" field is the section index (in the final object 1550e8d8bef9SDimitry Andric // file), but that is not known until after layout, so it must be fixed up 1551e8d8bef9SDimitry Andric // later 1552e8d8bef9SDimitry Andric if (const MCSymbolWasm *C = Section.getGroup()) { 1553e8d8bef9SDimitry Andric Comdats[C->getName()].emplace_back( 1554e8d8bef9SDimitry Andric WasmComdatEntry{wasm::WASM_COMDAT_SECTION, 1555e8d8bef9SDimitry Andric static_cast<uint32_t>(CustomSections.size())}); 1556e8d8bef9SDimitry Andric } 1557e8d8bef9SDimitry Andric 15580b57cec5SDimitry Andric CustomSections.emplace_back(Name, &Section); 15590b57cec5SDimitry Andric } 15600b57cec5SDimitry Andric } 15610b57cec5SDimitry Andric 1562e8d8bef9SDimitry Andric if (Mode != DwoMode::DwoOnly) { 15630b57cec5SDimitry Andric // Populate WasmIndices and DataLocations for defined symbols. 15640b57cec5SDimitry Andric for (const MCSymbol &S : Asm.symbols()) { 15650b57cec5SDimitry Andric // Ignore unnamed temporary symbols, which aren't ever exported, imported, 15660b57cec5SDimitry Andric // or used in relocations. 15670b57cec5SDimitry Andric if (S.isTemporary() && S.getName().empty()) 15680b57cec5SDimitry Andric continue; 15690b57cec5SDimitry Andric 15700b57cec5SDimitry Andric const auto &WS = static_cast<const MCSymbolWasm &>(S); 157181ad6265SDimitry Andric LLVM_DEBUG( 157281ad6265SDimitry Andric dbgs() << "MCSymbol: " 157381ad6265SDimitry Andric << toString(WS.getType().value_or(wasm::WASM_SYMBOL_TYPE_DATA)) 1574fe6060f1SDimitry Andric << " '" << S << "'" 15750b57cec5SDimitry Andric << " isDefined=" << S.isDefined() << " isExternal=" 15760b57cec5SDimitry Andric << S.isExternal() << " isTemporary=" << S.isTemporary() 15770b57cec5SDimitry Andric << " isWeak=" << WS.isWeak() << " isHidden=" << WS.isHidden() 15780b57cec5SDimitry Andric << " isVariable=" << WS.isVariable() << "\n"); 15790b57cec5SDimitry Andric 15800b57cec5SDimitry Andric if (WS.isVariable()) 15810b57cec5SDimitry Andric continue; 15820b57cec5SDimitry Andric if (WS.isComdat() && !WS.isDefined()) 15830b57cec5SDimitry Andric continue; 15840b57cec5SDimitry Andric 15850b57cec5SDimitry Andric if (WS.isFunction()) { 15860b57cec5SDimitry Andric unsigned Index; 15870b57cec5SDimitry Andric if (WS.isDefined()) { 15880b57cec5SDimitry Andric if (WS.getOffset() != 0) 15890b57cec5SDimitry Andric report_fatal_error( 15900b57cec5SDimitry Andric "function sections must contain one function each"); 15910b57cec5SDimitry Andric 15920b57cec5SDimitry Andric // A definition. Write out the function body. 15930b57cec5SDimitry Andric Index = NumFunctionImports + Functions.size(); 15940b57cec5SDimitry Andric WasmFunction Func; 15950b57cec5SDimitry Andric Func.SigIndex = getFunctionType(WS); 1596bdd1243dSDimitry Andric Func.Section = &WS.getSection(); 1597e8d8bef9SDimitry Andric assert(WasmIndices.count(&WS) == 0); 15980b57cec5SDimitry Andric WasmIndices[&WS] = Index; 15990b57cec5SDimitry Andric Functions.push_back(Func); 16000b57cec5SDimitry Andric 16010b57cec5SDimitry Andric auto &Section = static_cast<MCSectionWasm &>(WS.getSection()); 16020b57cec5SDimitry Andric if (const MCSymbolWasm *C = Section.getGroup()) { 16030b57cec5SDimitry Andric Comdats[C->getName()].emplace_back( 16040b57cec5SDimitry Andric WasmComdatEntry{wasm::WASM_COMDAT_FUNCTION, Index}); 16050b57cec5SDimitry Andric } 1606480093f4SDimitry Andric 1607480093f4SDimitry Andric if (WS.hasExportName()) { 1608480093f4SDimitry Andric wasm::WasmExport Export; 1609480093f4SDimitry Andric Export.Name = WS.getExportName(); 1610480093f4SDimitry Andric Export.Kind = wasm::WASM_EXTERNAL_FUNCTION; 1611480093f4SDimitry Andric Export.Index = Index; 1612480093f4SDimitry Andric Exports.push_back(Export); 1613480093f4SDimitry Andric } 16140b57cec5SDimitry Andric } else { 16150b57cec5SDimitry Andric // An import; the index was assigned above. 16160b57cec5SDimitry Andric Index = WasmIndices.find(&WS)->second; 16170b57cec5SDimitry Andric } 16180b57cec5SDimitry Andric 16190b57cec5SDimitry Andric LLVM_DEBUG(dbgs() << " -> function index: " << Index << "\n"); 16200b57cec5SDimitry Andric 16210b57cec5SDimitry Andric } else if (WS.isData()) { 16220b57cec5SDimitry Andric if (!isInSymtab(WS)) 16230b57cec5SDimitry Andric continue; 16240b57cec5SDimitry Andric 16250b57cec5SDimitry Andric if (!WS.isDefined()) { 16260b57cec5SDimitry Andric LLVM_DEBUG(dbgs() << " -> segment index: -1" 16270b57cec5SDimitry Andric << "\n"); 16280b57cec5SDimitry Andric continue; 16290b57cec5SDimitry Andric } 16300b57cec5SDimitry Andric 16310b57cec5SDimitry Andric if (!WS.getSize()) 16320b57cec5SDimitry Andric report_fatal_error("data symbols must have a size set with .size: " + 16330b57cec5SDimitry Andric WS.getName()); 16340b57cec5SDimitry Andric 16350b57cec5SDimitry Andric int64_t Size = 0; 16360b57cec5SDimitry Andric if (!WS.getSize()->evaluateAsAbsolute(Size, Layout)) 16370b57cec5SDimitry Andric report_fatal_error(".size expression must be evaluatable"); 16380b57cec5SDimitry Andric 16390b57cec5SDimitry Andric auto &DataSection = static_cast<MCSectionWasm &>(WS.getSection()); 16408bcb0991SDimitry Andric if (!DataSection.isWasmData()) 16418bcb0991SDimitry Andric report_fatal_error("data symbols must live in a data section: " + 16428bcb0991SDimitry Andric WS.getName()); 16430b57cec5SDimitry Andric 16440b57cec5SDimitry Andric // For each data symbol, export it in the symtab as a reference to the 16450b57cec5SDimitry Andric // corresponding Wasm data segment. 16460b57cec5SDimitry Andric wasm::WasmDataReference Ref = wasm::WasmDataReference{ 16475ffd83dbSDimitry Andric DataSection.getSegmentIndex(), Layout.getSymbolOffset(WS), 16485ffd83dbSDimitry Andric static_cast<uint64_t>(Size)}; 1649e8d8bef9SDimitry Andric assert(DataLocations.count(&WS) == 0); 16500b57cec5SDimitry Andric DataLocations[&WS] = Ref; 16510b57cec5SDimitry Andric LLVM_DEBUG(dbgs() << " -> segment index: " << Ref.Segment << "\n"); 16520b57cec5SDimitry Andric 16530b57cec5SDimitry Andric } else if (WS.isGlobal()) { 16540b57cec5SDimitry Andric // A "true" Wasm global (currently just __stack_pointer) 16555ffd83dbSDimitry Andric if (WS.isDefined()) { 16565ffd83dbSDimitry Andric wasm::WasmGlobal Global; 16575ffd83dbSDimitry Andric Global.Type = WS.getGlobalType(); 16585ffd83dbSDimitry Andric Global.Index = NumGlobalImports + Globals.size(); 165981ad6265SDimitry Andric Global.InitExpr.Extended = false; 16605ffd83dbSDimitry Andric switch (Global.Type.Type) { 16615ffd83dbSDimitry Andric case wasm::WASM_TYPE_I32: 166281ad6265SDimitry Andric Global.InitExpr.Inst.Opcode = wasm::WASM_OPCODE_I32_CONST; 16635ffd83dbSDimitry Andric break; 16645ffd83dbSDimitry Andric case wasm::WASM_TYPE_I64: 166581ad6265SDimitry Andric Global.InitExpr.Inst.Opcode = wasm::WASM_OPCODE_I64_CONST; 16665ffd83dbSDimitry Andric break; 16675ffd83dbSDimitry Andric case wasm::WASM_TYPE_F32: 166881ad6265SDimitry Andric Global.InitExpr.Inst.Opcode = wasm::WASM_OPCODE_F32_CONST; 16695ffd83dbSDimitry Andric break; 16705ffd83dbSDimitry Andric case wasm::WASM_TYPE_F64: 167181ad6265SDimitry Andric Global.InitExpr.Inst.Opcode = wasm::WASM_OPCODE_F64_CONST; 16725ffd83dbSDimitry Andric break; 16735ffd83dbSDimitry Andric case wasm::WASM_TYPE_EXTERNREF: 167481ad6265SDimitry Andric Global.InitExpr.Inst.Opcode = wasm::WASM_OPCODE_REF_NULL; 16755ffd83dbSDimitry Andric break; 16765ffd83dbSDimitry Andric default: 16775ffd83dbSDimitry Andric llvm_unreachable("unexpected type"); 16785ffd83dbSDimitry Andric } 1679e8d8bef9SDimitry Andric assert(WasmIndices.count(&WS) == 0); 16805ffd83dbSDimitry Andric WasmIndices[&WS] = Global.Index; 16815ffd83dbSDimitry Andric Globals.push_back(Global); 16825ffd83dbSDimitry Andric } else { 16830b57cec5SDimitry Andric // An import; the index was assigned above 16840b57cec5SDimitry Andric LLVM_DEBUG(dbgs() << " -> global index: " 16850b57cec5SDimitry Andric << WasmIndices.find(&WS)->second << "\n"); 16865ffd83dbSDimitry Andric } 1687e8d8bef9SDimitry Andric } else if (WS.isTable()) { 1688e8d8bef9SDimitry Andric if (WS.isDefined()) { 1689e8d8bef9SDimitry Andric wasm::WasmTable Table; 1690e8d8bef9SDimitry Andric Table.Index = NumTableImports + Tables.size(); 1691fe6060f1SDimitry Andric Table.Type = WS.getTableType(); 1692e8d8bef9SDimitry Andric assert(WasmIndices.count(&WS) == 0); 1693e8d8bef9SDimitry Andric WasmIndices[&WS] = Table.Index; 1694e8d8bef9SDimitry Andric Tables.push_back(Table); 1695e8d8bef9SDimitry Andric } 1696e8d8bef9SDimitry Andric LLVM_DEBUG(dbgs() << " -> table index: " 1697e8d8bef9SDimitry Andric << WasmIndices.find(&WS)->second << "\n"); 1698fe6060f1SDimitry Andric } else if (WS.isTag()) { 1699349cc55cSDimitry Andric // C++ exception symbol (__cpp_exception) or longjmp symbol 1700349cc55cSDimitry Andric // (__c_longjmp) 17010b57cec5SDimitry Andric unsigned Index; 17020b57cec5SDimitry Andric if (WS.isDefined()) { 1703349cc55cSDimitry Andric Index = NumTagImports + TagTypes.size(); 1704349cc55cSDimitry Andric uint32_t SigIndex = getTagType(WS); 1705e8d8bef9SDimitry Andric assert(WasmIndices.count(&WS) == 0); 17060b57cec5SDimitry Andric WasmIndices[&WS] = Index; 1707349cc55cSDimitry Andric TagTypes.push_back(SigIndex); 17080b57cec5SDimitry Andric } else { 17090b57cec5SDimitry Andric // An import; the index was assigned above. 17100b57cec5SDimitry Andric assert(WasmIndices.count(&WS) > 0); 17110b57cec5SDimitry Andric } 1712fe6060f1SDimitry Andric LLVM_DEBUG(dbgs() << " -> tag index: " << WasmIndices.find(&WS)->second 1713fe6060f1SDimitry Andric << "\n"); 17140b57cec5SDimitry Andric 17150b57cec5SDimitry Andric } else { 17160b57cec5SDimitry Andric assert(WS.isSection()); 17170b57cec5SDimitry Andric } 17180b57cec5SDimitry Andric } 17190b57cec5SDimitry Andric 17200b57cec5SDimitry Andric // Populate WasmIndices and DataLocations for aliased symbols. We need to 17210b57cec5SDimitry Andric // process these in a separate pass because we need to have processed the 17220b57cec5SDimitry Andric // target of the alias before the alias itself and the symbols are not 17230b57cec5SDimitry Andric // necessarily ordered in this way. 17240b57cec5SDimitry Andric for (const MCSymbol &S : Asm.symbols()) { 17250b57cec5SDimitry Andric if (!S.isVariable()) 17260b57cec5SDimitry Andric continue; 17270b57cec5SDimitry Andric 17280b57cec5SDimitry Andric assert(S.isDefined()); 17290b57cec5SDimitry Andric 1730e8d8bef9SDimitry Andric const auto *BS = Layout.getBaseSymbol(S); 1731e8d8bef9SDimitry Andric if (!BS) 1732e8d8bef9SDimitry Andric report_fatal_error(Twine(S.getName()) + 1733e8d8bef9SDimitry Andric ": absolute addressing not supported!"); 1734e8d8bef9SDimitry Andric const MCSymbolWasm *Base = cast<MCSymbolWasm>(BS); 17355ffd83dbSDimitry Andric 17360b57cec5SDimitry Andric // Find the target symbol of this weak alias and export that index 17370b57cec5SDimitry Andric const auto &WS = static_cast<const MCSymbolWasm &>(S); 1738e8d8bef9SDimitry Andric LLVM_DEBUG(dbgs() << WS.getName() << ": weak alias of '" << *Base 1739e8d8bef9SDimitry Andric << "'\n"); 17400b57cec5SDimitry Andric 17415ffd83dbSDimitry Andric if (Base->isFunction()) { 17425ffd83dbSDimitry Andric assert(WasmIndices.count(Base) > 0); 17435ffd83dbSDimitry Andric uint32_t WasmIndex = WasmIndices.find(Base)->second; 17440b57cec5SDimitry Andric assert(WasmIndices.count(&WS) == 0); 17450b57cec5SDimitry Andric WasmIndices[&WS] = WasmIndex; 17460b57cec5SDimitry Andric LLVM_DEBUG(dbgs() << " -> index:" << WasmIndex << "\n"); 17475ffd83dbSDimitry Andric } else if (Base->isData()) { 17485ffd83dbSDimitry Andric auto &DataSection = static_cast<MCSectionWasm &>(WS.getSection()); 17495ffd83dbSDimitry Andric uint64_t Offset = Layout.getSymbolOffset(S); 17505ffd83dbSDimitry Andric int64_t Size = 0; 17515ffd83dbSDimitry Andric // For data symbol alias we use the size of the base symbol as the 17525ffd83dbSDimitry Andric // size of the alias. When an offset from the base is involved this 17535ffd83dbSDimitry Andric // can result in a offset + size goes past the end of the data section 17545ffd83dbSDimitry Andric // which out object format doesn't support. So we must clamp it. 17555ffd83dbSDimitry Andric if (!Base->getSize()->evaluateAsAbsolute(Size, Layout)) 17565ffd83dbSDimitry Andric report_fatal_error(".size expression must be evaluatable"); 17575ffd83dbSDimitry Andric const WasmDataSegment &Segment = 17585ffd83dbSDimitry Andric DataSegments[DataSection.getSegmentIndex()]; 17595ffd83dbSDimitry Andric Size = 17605ffd83dbSDimitry Andric std::min(static_cast<uint64_t>(Size), Segment.Data.size() - Offset); 17615ffd83dbSDimitry Andric wasm::WasmDataReference Ref = wasm::WasmDataReference{ 17625ffd83dbSDimitry Andric DataSection.getSegmentIndex(), 17635ffd83dbSDimitry Andric static_cast<uint32_t>(Layout.getSymbolOffset(S)), 17645ffd83dbSDimitry Andric static_cast<uint32_t>(Size)}; 17650b57cec5SDimitry Andric DataLocations[&WS] = Ref; 17660b57cec5SDimitry Andric LLVM_DEBUG(dbgs() << " -> index:" << Ref.Segment << "\n"); 17670b57cec5SDimitry Andric } else { 1768fe6060f1SDimitry Andric report_fatal_error("don't yet support global/tag aliases"); 17690b57cec5SDimitry Andric } 17700b57cec5SDimitry Andric } 1771e8d8bef9SDimitry Andric } 17720b57cec5SDimitry Andric 17730b57cec5SDimitry Andric // Finally, populate the symbol table itself, in its "natural" order. 17740b57cec5SDimitry Andric for (const MCSymbol &S : Asm.symbols()) { 17750b57cec5SDimitry Andric const auto &WS = static_cast<const MCSymbolWasm &>(S); 17760b57cec5SDimitry Andric if (!isInSymtab(WS)) { 17770b57cec5SDimitry Andric WS.setIndex(InvalidIndex); 17780b57cec5SDimitry Andric continue; 17790b57cec5SDimitry Andric } 17800b57cec5SDimitry Andric LLVM_DEBUG(dbgs() << "adding to symtab: " << WS << "\n"); 17810b57cec5SDimitry Andric 17820b57cec5SDimitry Andric uint32_t Flags = 0; 17830b57cec5SDimitry Andric if (WS.isWeak()) 17840b57cec5SDimitry Andric Flags |= wasm::WASM_SYMBOL_BINDING_WEAK; 17850b57cec5SDimitry Andric if (WS.isHidden()) 17860b57cec5SDimitry Andric Flags |= wasm::WASM_SYMBOL_VISIBILITY_HIDDEN; 17870b57cec5SDimitry Andric if (!WS.isExternal() && WS.isDefined()) 17880b57cec5SDimitry Andric Flags |= wasm::WASM_SYMBOL_BINDING_LOCAL; 17890b57cec5SDimitry Andric if (WS.isUndefined()) 17900b57cec5SDimitry Andric Flags |= wasm::WASM_SYMBOL_UNDEFINED; 17918bcb0991SDimitry Andric if (WS.isNoStrip()) { 17928bcb0991SDimitry Andric Flags |= wasm::WASM_SYMBOL_NO_STRIP; 17938bcb0991SDimitry Andric if (isEmscripten()) { 17940b57cec5SDimitry Andric Flags |= wasm::WASM_SYMBOL_EXPORTED; 17958bcb0991SDimitry Andric } 17968bcb0991SDimitry Andric } 1797480093f4SDimitry Andric if (WS.hasImportName()) 17980b57cec5SDimitry Andric Flags |= wasm::WASM_SYMBOL_EXPLICIT_NAME; 1799480093f4SDimitry Andric if (WS.hasExportName()) 1800480093f4SDimitry Andric Flags |= wasm::WASM_SYMBOL_EXPORTED; 1801349cc55cSDimitry Andric if (WS.isTLS()) 1802349cc55cSDimitry Andric Flags |= wasm::WASM_SYMBOL_TLS; 18030b57cec5SDimitry Andric 18040b57cec5SDimitry Andric wasm::WasmSymbolInfo Info; 18050b57cec5SDimitry Andric Info.Name = WS.getName(); 180681ad6265SDimitry Andric Info.Kind = WS.getType().value_or(wasm::WASM_SYMBOL_TYPE_DATA); 18070b57cec5SDimitry Andric Info.Flags = Flags; 18080b57cec5SDimitry Andric if (!WS.isData()) { 18090b57cec5SDimitry Andric assert(WasmIndices.count(&WS) > 0); 18100b57cec5SDimitry Andric Info.ElementIndex = WasmIndices.find(&WS)->second; 18110b57cec5SDimitry Andric } else if (WS.isDefined()) { 18120b57cec5SDimitry Andric assert(DataLocations.count(&WS) > 0); 18130b57cec5SDimitry Andric Info.DataRef = DataLocations.find(&WS)->second; 18140b57cec5SDimitry Andric } 18150b57cec5SDimitry Andric WS.setIndex(SymbolInfos.size()); 18160b57cec5SDimitry Andric SymbolInfos.emplace_back(Info); 18170b57cec5SDimitry Andric } 18180b57cec5SDimitry Andric 18190b57cec5SDimitry Andric { 18200b57cec5SDimitry Andric auto HandleReloc = [&](const WasmRelocationEntry &Rel) { 18210b57cec5SDimitry Andric // Functions referenced by a relocation need to put in the table. This is 18220b57cec5SDimitry Andric // purely to make the object file's provisional values readable, and is 18230b57cec5SDimitry Andric // ignored by the linker, which re-calculates the relocations itself. 18240b57cec5SDimitry Andric if (Rel.Type != wasm::R_WASM_TABLE_INDEX_I32 && 1825e8d8bef9SDimitry Andric Rel.Type != wasm::R_WASM_TABLE_INDEX_I64 && 18265ffd83dbSDimitry Andric Rel.Type != wasm::R_WASM_TABLE_INDEX_SLEB && 1827e8d8bef9SDimitry Andric Rel.Type != wasm::R_WASM_TABLE_INDEX_SLEB64 && 1828fe6060f1SDimitry Andric Rel.Type != wasm::R_WASM_TABLE_INDEX_REL_SLEB && 1829fe6060f1SDimitry Andric Rel.Type != wasm::R_WASM_TABLE_INDEX_REL_SLEB64) 18300b57cec5SDimitry Andric return; 18310b57cec5SDimitry Andric assert(Rel.Symbol->isFunction()); 18325ffd83dbSDimitry Andric const MCSymbolWasm *Base = 18335ffd83dbSDimitry Andric cast<MCSymbolWasm>(Layout.getBaseSymbol(*Rel.Symbol)); 18345ffd83dbSDimitry Andric uint32_t FunctionIndex = WasmIndices.find(Base)->second; 18350b57cec5SDimitry Andric uint32_t TableIndex = TableElems.size() + InitialTableOffset; 18365ffd83dbSDimitry Andric if (TableIndices.try_emplace(Base, TableIndex).second) { 18375ffd83dbSDimitry Andric LLVM_DEBUG(dbgs() << " -> adding " << Base->getName() 18380b57cec5SDimitry Andric << " to table: " << TableIndex << "\n"); 18390b57cec5SDimitry Andric TableElems.push_back(FunctionIndex); 18405ffd83dbSDimitry Andric registerFunctionType(*Base); 18410b57cec5SDimitry Andric } 18420b57cec5SDimitry Andric }; 18430b57cec5SDimitry Andric 18440b57cec5SDimitry Andric for (const WasmRelocationEntry &RelEntry : CodeRelocations) 18450b57cec5SDimitry Andric HandleReloc(RelEntry); 18460b57cec5SDimitry Andric for (const WasmRelocationEntry &RelEntry : DataRelocations) 18470b57cec5SDimitry Andric HandleReloc(RelEntry); 18480b57cec5SDimitry Andric } 18490b57cec5SDimitry Andric 18500b57cec5SDimitry Andric // Translate .init_array section contents into start functions. 18510b57cec5SDimitry Andric for (const MCSection &S : Asm) { 18520b57cec5SDimitry Andric const auto &WS = static_cast<const MCSectionWasm &>(S); 18535f757f3fSDimitry Andric if (WS.getName().starts_with(".fini_array")) 18540b57cec5SDimitry Andric report_fatal_error(".fini_array sections are unsupported"); 18555f757f3fSDimitry Andric if (!WS.getName().starts_with(".init_array")) 18560b57cec5SDimitry Andric continue; 18570b57cec5SDimitry Andric if (WS.getFragmentList().empty()) 18580b57cec5SDimitry Andric continue; 18590b57cec5SDimitry Andric 18600b57cec5SDimitry Andric // init_array is expected to contain a single non-empty data fragment 18610b57cec5SDimitry Andric if (WS.getFragmentList().size() != 3) 18620b57cec5SDimitry Andric report_fatal_error("only one .init_array section fragment supported"); 18630b57cec5SDimitry Andric 18640b57cec5SDimitry Andric auto IT = WS.begin(); 18650b57cec5SDimitry Andric const MCFragment &EmptyFrag = *IT; 18660b57cec5SDimitry Andric if (EmptyFrag.getKind() != MCFragment::FT_Data) 18670b57cec5SDimitry Andric report_fatal_error(".init_array section should be aligned"); 18680b57cec5SDimitry Andric 18690b57cec5SDimitry Andric IT = std::next(IT); 18700b57cec5SDimitry Andric const MCFragment &AlignFrag = *IT; 18710b57cec5SDimitry Andric if (AlignFrag.getKind() != MCFragment::FT_Align) 18720b57cec5SDimitry Andric report_fatal_error(".init_array section should be aligned"); 187381ad6265SDimitry Andric if (cast<MCAlignFragment>(AlignFrag).getAlignment() != 187481ad6265SDimitry Andric Align(is64Bit() ? 8 : 4)) 18750b57cec5SDimitry Andric report_fatal_error(".init_array section should be aligned for pointers"); 18760b57cec5SDimitry Andric 18770b57cec5SDimitry Andric const MCFragment &Frag = *std::next(IT); 18780b57cec5SDimitry Andric if (Frag.hasInstructions() || Frag.getKind() != MCFragment::FT_Data) 18790b57cec5SDimitry Andric report_fatal_error("only data supported in .init_array section"); 18800b57cec5SDimitry Andric 18810b57cec5SDimitry Andric uint16_t Priority = UINT16_MAX; 18820b57cec5SDimitry Andric unsigned PrefixLength = strlen(".init_array"); 18835ffd83dbSDimitry Andric if (WS.getName().size() > PrefixLength) { 18845ffd83dbSDimitry Andric if (WS.getName()[PrefixLength] != '.') 18850b57cec5SDimitry Andric report_fatal_error( 18860b57cec5SDimitry Andric ".init_array section priority should start with '.'"); 18875ffd83dbSDimitry Andric if (WS.getName().substr(PrefixLength + 1).getAsInteger(10, Priority)) 18880b57cec5SDimitry Andric report_fatal_error("invalid .init_array section priority"); 18890b57cec5SDimitry Andric } 18900b57cec5SDimitry Andric const auto &DataFrag = cast<MCDataFragment>(Frag); 18910b57cec5SDimitry Andric const SmallVectorImpl<char> &Contents = DataFrag.getContents(); 18920b57cec5SDimitry Andric for (const uint8_t * 18930b57cec5SDimitry Andric P = (const uint8_t *)Contents.data(), 18940b57cec5SDimitry Andric *End = (const uint8_t *)Contents.data() + Contents.size(); 18950b57cec5SDimitry Andric P != End; ++P) { 18960b57cec5SDimitry Andric if (*P != 0) 18970b57cec5SDimitry Andric report_fatal_error("non-symbolic data in .init_array section"); 18980b57cec5SDimitry Andric } 18990b57cec5SDimitry Andric for (const MCFixup &Fixup : DataFrag.getFixups()) { 19000b57cec5SDimitry Andric assert(Fixup.getKind() == 19010b57cec5SDimitry Andric MCFixup::getKindForSize(is64Bit() ? 8 : 4, false)); 19020b57cec5SDimitry Andric const MCExpr *Expr = Fixup.getValue(); 19030b57cec5SDimitry Andric auto *SymRef = dyn_cast<MCSymbolRefExpr>(Expr); 19040b57cec5SDimitry Andric if (!SymRef) 19050b57cec5SDimitry Andric report_fatal_error("fixups in .init_array should be symbol references"); 19060b57cec5SDimitry Andric const auto &TargetSym = cast<const MCSymbolWasm>(SymRef->getSymbol()); 19070b57cec5SDimitry Andric if (TargetSym.getIndex() == InvalidIndex) 19085ffd83dbSDimitry Andric report_fatal_error("symbols in .init_array should exist in symtab"); 19090b57cec5SDimitry Andric if (!TargetSym.isFunction()) 19100b57cec5SDimitry Andric report_fatal_error("symbols in .init_array should be for functions"); 19110b57cec5SDimitry Andric InitFuncs.push_back( 19120b57cec5SDimitry Andric std::make_pair(Priority, TargetSym.getIndex())); 19130b57cec5SDimitry Andric } 19140b57cec5SDimitry Andric } 19150b57cec5SDimitry Andric 19160b57cec5SDimitry Andric // Write out the Wasm header. 19170b57cec5SDimitry Andric writeHeader(Asm); 19180b57cec5SDimitry Andric 1919e8d8bef9SDimitry Andric uint32_t CodeSectionIndex, DataSectionIndex; 1920e8d8bef9SDimitry Andric if (Mode != DwoMode::DwoOnly) { 19210b57cec5SDimitry Andric writeTypeSection(Signatures); 19220b57cec5SDimitry Andric writeImportSection(Imports, DataSize, TableElems.size()); 19230b57cec5SDimitry Andric writeFunctionSection(Functions); 1924e8d8bef9SDimitry Andric writeTableSection(Tables); 19250b57cec5SDimitry Andric // Skip the "memory" section; we import the memory instead. 1926349cc55cSDimitry Andric writeTagSection(TagTypes); 19275ffd83dbSDimitry Andric writeGlobalSection(Globals); 19280b57cec5SDimitry Andric writeExportSection(Exports); 1929fe6060f1SDimitry Andric const MCSymbol *IndirectFunctionTable = 1930fe6060f1SDimitry Andric Asm.getContext().lookupSymbol("__indirect_function_table"); 1931fe6060f1SDimitry Andric writeElemSection(cast_or_null<const MCSymbolWasm>(IndirectFunctionTable), 1932fe6060f1SDimitry Andric TableElems); 19330b57cec5SDimitry Andric writeDataCountSection(); 1934e8d8bef9SDimitry Andric 1935e8d8bef9SDimitry Andric CodeSectionIndex = writeCodeSection(Asm, Layout, Functions); 1936e8d8bef9SDimitry Andric DataSectionIndex = writeDataSection(Layout); 1937e8d8bef9SDimitry Andric } 1938e8d8bef9SDimitry Andric 1939e8d8bef9SDimitry Andric // The Sections in the COMDAT list have placeholder indices (their index among 1940e8d8bef9SDimitry Andric // custom sections, rather than among all sections). Fix them up here. 1941e8d8bef9SDimitry Andric for (auto &Group : Comdats) { 1942e8d8bef9SDimitry Andric for (auto &Entry : Group.second) { 1943e8d8bef9SDimitry Andric if (Entry.Kind == wasm::WASM_COMDAT_SECTION) { 1944e8d8bef9SDimitry Andric Entry.Index += SectionCount; 1945e8d8bef9SDimitry Andric } 1946e8d8bef9SDimitry Andric } 1947e8d8bef9SDimitry Andric } 19480b57cec5SDimitry Andric for (auto &CustomSection : CustomSections) 19490b57cec5SDimitry Andric writeCustomSection(CustomSection, Asm, Layout); 1950e8d8bef9SDimitry Andric 1951e8d8bef9SDimitry Andric if (Mode != DwoMode::DwoOnly) { 19520b57cec5SDimitry Andric writeLinkingMetaDataSection(SymbolInfos, InitFuncs, Comdats); 1953e8d8bef9SDimitry Andric 19540b57cec5SDimitry Andric writeRelocSection(CodeSectionIndex, "CODE", CodeRelocations); 19550b57cec5SDimitry Andric writeRelocSection(DataSectionIndex, "DATA", DataRelocations); 1956e8d8bef9SDimitry Andric } 19570b57cec5SDimitry Andric writeCustomRelocSections(); 19580b57cec5SDimitry Andric if (ProducersSection) 19590b57cec5SDimitry Andric writeCustomSection(*ProducersSection, Asm, Layout); 19600b57cec5SDimitry Andric if (TargetFeaturesSection) 19610b57cec5SDimitry Andric writeCustomSection(*TargetFeaturesSection, Asm, Layout); 19620b57cec5SDimitry Andric 19630b57cec5SDimitry Andric // TODO: Translate the .comment section to the output. 1964e8d8bef9SDimitry Andric return W->OS.tell() - StartOffset; 19650b57cec5SDimitry Andric } 19660b57cec5SDimitry Andric 19670b57cec5SDimitry Andric std::unique_ptr<MCObjectWriter> 19680b57cec5SDimitry Andric llvm::createWasmObjectWriter(std::unique_ptr<MCWasmObjectTargetWriter> MOTW, 19690b57cec5SDimitry Andric raw_pwrite_stream &OS) { 19708bcb0991SDimitry Andric return std::make_unique<WasmObjectWriter>(std::move(MOTW), OS); 19710b57cec5SDimitry Andric } 1972e8d8bef9SDimitry Andric 1973e8d8bef9SDimitry Andric std::unique_ptr<MCObjectWriter> 1974e8d8bef9SDimitry Andric llvm::createWasmDwoObjectWriter(std::unique_ptr<MCWasmObjectTargetWriter> MOTW, 1975e8d8bef9SDimitry Andric raw_pwrite_stream &OS, 1976e8d8bef9SDimitry Andric raw_pwrite_stream &DwoOS) { 1977e8d8bef9SDimitry Andric return std::make_unique<WasmObjectWriter>(std::move(MOTW), OS, DwoOS); 1978e8d8bef9SDimitry Andric } 1979