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| author | Alon Zakai <azakai@google.com> | 2019-12-19 09:04:08 -0800 |
|---|---|---|
| committer | GitHub <noreply@github.com> | 2019-12-19 09:04:08 -0800 |
| commit | 4d28d3f32e7f213e300b24bc61c3f0ac9d6e1ab6 (patch) | |
| tree | 91bffc2d47b1fe4bba01e7ada77006ef340bd138 /third_party/llvm-project/include/llvm/Object/Wasm.h | |
| parent | 0048f5b004ddf50e750aa335d0be314a73852058 (diff) | |
| download | binaryen-4d28d3f32e7f213e300b24bc61c3f0ac9d6e1ab6.tar.gz binaryen-4d28d3f32e7f213e300b24bc61c3f0ac9d6e1ab6.tar.bz2 binaryen-4d28d3f32e7f213e300b24bc61c3f0ac9d6e1ab6.zip | |
DWARF parsing and writing support using LLVM (#2520)
This imports LLVM code for DWARF handling. That code has the
Apache 2 license like us. It's also the same code used to
emit DWARF in the common toolchain, so it seems like a safe choice.
This adds two passes: --dwarfdump which runs the same code LLVM
runs for llvm-dwarfdump. This shows we can parse it ok, and will
be useful for debugging. And --dwarfupdate writes out the DWARF
sections (unchanged from what we read, so it just roundtrips - for
updating we need #2515).
This puts LLVM in thirdparty which is added here.
All the LLVM code is behind USE_LLVM_DWARF, which is on
by default, but off in JS for now, as it increases code size by 20%.
This current approach imports the LLVM files directly. This is not
how they are intended to be used, so it required a bunch of
local changes - more than I expected actually, for the platform-specific
stuff. For now this seems to work, so it may be good enough, but
in the long term we may want to switch to linking against libllvm.
A downside to doing that is that binaryen users would need to
have an LLVM build, and even in the waterfall builds we'd have a
problem - while we ship LLVM there anyhow, we constantly update
it, which means that binaryen would need to be on latest llvm all
the time too (which otherwise, given DWARF is quite stable, we
might not need to constantly update).
An even larger issue is that as I did this work I learned about how
DWARF works in LLVM, and while the reading code is easy to
reuse, the writing code is trickier. The main code path is heavily
integrated with the MC layer, which we don't have - we might want
to create a "fake MC layer" for that, but it sounds hard. Instead,
there is the YAML path which is used mostly for testing, and which
can convert DWARF to and from YAML and from binary. Using
the non-YAML parts there, we can convert binary DWARF to
the YAML layer's nice Info data, then convert that to binary. This
works, however, this is not the path LLVM uses normally, and it
supports only some basic DWARF sections - I had to add ranges
support, in fact. So if we need more complex things, we may end
up needing to use the MC layer approach, or consider some other
DWARF library. However, hopefully that should not affect the core
binaryen code which just calls a library for DWARF stuff.
Helps #2400
Diffstat (limited to 'third_party/llvm-project/include/llvm/Object/Wasm.h')
| -rw-r--r-- | third_party/llvm-project/include/llvm/Object/Wasm.h | 356 |
1 files changed, 356 insertions, 0 deletions
diff --git a/third_party/llvm-project/include/llvm/Object/Wasm.h b/third_party/llvm-project/include/llvm/Object/Wasm.h new file mode 100644 index 000000000..e130ea32e --- /dev/null +++ b/third_party/llvm-project/include/llvm/Object/Wasm.h @@ -0,0 +1,356 @@ +//===- Wasm.h - Wasm object file implementation -----------------*- C++ -*-===// +// +// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. +// See https://llvm.org/LICENSE.txt for license information. +// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception +// +//===----------------------------------------------------------------------===// +// +// This file declares the WasmObjectFile class, which implements the ObjectFile +// interface for Wasm files. +// +// See: https://github.com/WebAssembly/design/blob/master/BinaryEncoding.md +// +//===----------------------------------------------------------------------===// + +#ifndef LLVM_OBJECT_WASM_H +#define LLVM_OBJECT_WASM_H + +#include "llvm/ADT/ArrayRef.h" +#include "llvm/ADT/StringMap.h" +#include "llvm/ADT/StringRef.h" +#include "llvm/BinaryFormat/Wasm.h" +#include "llvm/Config/llvm-config.h" +#include "llvm/MC/MCSymbolWasm.h" +#include "llvm/Object/Binary.h" +#include "llvm/Object/ObjectFile.h" +#include "llvm/Support/Error.h" +#include "llvm/Support/MemoryBuffer.h" +#include <cstddef> +#include <cstdint> +#include <vector> + +namespace llvm { +namespace object { + +class WasmSymbol { +public: + WasmSymbol(const wasm::WasmSymbolInfo &Info, + const wasm::WasmGlobalType *GlobalType, + const wasm::WasmEventType *EventType, + const wasm::WasmSignature *Signature) + : Info(Info), GlobalType(GlobalType), EventType(EventType), + Signature(Signature) {} + + const wasm::WasmSymbolInfo &Info; + const wasm::WasmGlobalType *GlobalType; + const wasm::WasmEventType *EventType; + const wasm::WasmSignature *Signature; + + bool isTypeFunction() const { + return Info.Kind == wasm::WASM_SYMBOL_TYPE_FUNCTION; + } + + bool isTypeData() const { return Info.Kind == wasm::WASM_SYMBOL_TYPE_DATA; } + + bool isTypeGlobal() const { + return Info.Kind == wasm::WASM_SYMBOL_TYPE_GLOBAL; + } + + bool isTypeSection() const { + return Info.Kind == wasm::WASM_SYMBOL_TYPE_SECTION; + } + + bool isTypeEvent() const { return Info.Kind == wasm::WASM_SYMBOL_TYPE_EVENT; } + + bool isDefined() const { return !isUndefined(); } + + bool isUndefined() const { + return (Info.Flags & wasm::WASM_SYMBOL_UNDEFINED) != 0; + } + + bool isBindingWeak() const { + return getBinding() == wasm::WASM_SYMBOL_BINDING_WEAK; + } + + bool isBindingGlobal() const { + return getBinding() == wasm::WASM_SYMBOL_BINDING_GLOBAL; + } + + bool isBindingLocal() const { + return getBinding() == wasm::WASM_SYMBOL_BINDING_LOCAL; + } + + unsigned getBinding() const { + return Info.Flags & wasm::WASM_SYMBOL_BINDING_MASK; + } + + bool isHidden() const { + return getVisibility() == wasm::WASM_SYMBOL_VISIBILITY_HIDDEN; + } + + unsigned getVisibility() const { + return Info.Flags & wasm::WASM_SYMBOL_VISIBILITY_MASK; + } + + void print(raw_ostream &Out) const; + +#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP) + LLVM_DUMP_METHOD void dump() const; +#endif +}; + +struct WasmSection { + WasmSection() = default; + + uint32_t Type = 0; // Section type (See below) + uint32_t Offset = 0; // Offset with in the file + StringRef Name; // Section name (User-defined sections only) + ArrayRef<uint8_t> Content; // Section content + std::vector<wasm::WasmRelocation> Relocations; // Relocations for this section +}; + +struct WasmSegment { + uint32_t SectionOffset; + wasm::WasmDataSegment Data; +}; + +class WasmObjectFile : public ObjectFile { + +public: + WasmObjectFile(MemoryBufferRef Object, Error &Err); + + const wasm::WasmObjectHeader &getHeader() const; + const WasmSymbol &getWasmSymbol(const DataRefImpl &Symb) const; + const WasmSymbol &getWasmSymbol(const SymbolRef &Symbol) const; + const WasmSection &getWasmSection(const SectionRef &Section) const; + const wasm::WasmRelocation &getWasmRelocation(const RelocationRef &Ref) const; + + static bool classof(const Binary *v) { return v->isWasm(); } + + const wasm::WasmDylinkInfo &dylinkInfo() const { return DylinkInfo; } + const wasm::WasmProducerInfo &getProducerInfo() const { return ProducerInfo; } + ArrayRef<wasm::WasmFeatureEntry> getTargetFeatures() const { + return TargetFeatures; + } + ArrayRef<wasm::WasmSignature> types() const { return Signatures; } + ArrayRef<uint32_t> functionTypes() const { return FunctionTypes; } + ArrayRef<wasm::WasmImport> imports() const { return Imports; } + ArrayRef<wasm::WasmTable> tables() const { return Tables; } + ArrayRef<wasm::WasmLimits> memories() const { return Memories; } + ArrayRef<wasm::WasmGlobal> globals() const { return Globals; } + ArrayRef<wasm::WasmEvent> events() const { return Events; } + ArrayRef<wasm::WasmExport> exports() const { return Exports; } + ArrayRef<WasmSymbol> syms() const { return Symbols; } + const wasm::WasmLinkingData &linkingData() const { return LinkingData; } + uint32_t getNumberOfSymbols() const { return Symbols.size(); } + ArrayRef<wasm::WasmElemSegment> elements() const { return ElemSegments; } + ArrayRef<WasmSegment> dataSegments() const { return DataSegments; } + ArrayRef<wasm::WasmFunction> functions() const { return Functions; } + ArrayRef<wasm::WasmFunctionName> debugNames() const { return DebugNames; } + uint32_t startFunction() const { return StartFunction; } + uint32_t getNumImportedGlobals() const { return NumImportedGlobals; } + uint32_t getNumImportedFunctions() const { return NumImportedFunctions; } + uint32_t getNumImportedEvents() const { return NumImportedEvents; } + void moveSymbolNext(DataRefImpl &Symb) const override; + + uint32_t getSymbolFlags(DataRefImpl Symb) const override; + + basic_symbol_iterator symbol_begin() const override; + + basic_symbol_iterator symbol_end() const override; + Expected<StringRef> getSymbolName(DataRefImpl Symb) const override; + + Expected<uint64_t> getSymbolAddress(DataRefImpl Symb) const override; + uint64_t getWasmSymbolValue(const WasmSymbol &Sym) const; + uint64_t getSymbolValueImpl(DataRefImpl Symb) const override; + uint32_t getSymbolAlignment(DataRefImpl Symb) const override; + uint64_t getCommonSymbolSizeImpl(DataRefImpl Symb) const override; + Expected<SymbolRef::Type> getSymbolType(DataRefImpl Symb) const override; + Expected<section_iterator> getSymbolSection(DataRefImpl Symb) const override; + + // Overrides from SectionRef. + void moveSectionNext(DataRefImpl &Sec) const override; + Expected<StringRef> getSectionName(DataRefImpl Sec) const override; + uint64_t getSectionAddress(DataRefImpl Sec) const override; + uint64_t getSectionIndex(DataRefImpl Sec) const override; + uint64_t getSectionSize(DataRefImpl Sec) const override; + Expected<ArrayRef<uint8_t>> + getSectionContents(DataRefImpl Sec) const override; + uint64_t getSectionAlignment(DataRefImpl Sec) const override; + bool isSectionCompressed(DataRefImpl Sec) const override; + bool isSectionText(DataRefImpl Sec) const override; + bool isSectionData(DataRefImpl Sec) const override; + bool isSectionBSS(DataRefImpl Sec) const override; + bool isSectionVirtual(DataRefImpl Sec) const override; + bool isSectionBitcode(DataRefImpl Sec) const override; + relocation_iterator section_rel_begin(DataRefImpl Sec) const override; + relocation_iterator section_rel_end(DataRefImpl Sec) const override; + + // Overrides from RelocationRef. + void moveRelocationNext(DataRefImpl &Rel) const override; + uint64_t getRelocationOffset(DataRefImpl Rel) const override; + symbol_iterator getRelocationSymbol(DataRefImpl Rel) const override; + uint64_t getRelocationType(DataRefImpl Rel) const override; + void getRelocationTypeName(DataRefImpl Rel, + SmallVectorImpl<char> &Result) const override; + + section_iterator section_begin() const override; + section_iterator section_end() const override; + uint8_t getBytesInAddress() const override; + StringRef getFileFormatName() const override; + Triple::ArchType getArch() const override; + SubtargetFeatures getFeatures() const override; + bool isRelocatableObject() const override; + bool isSharedObject() const; + + struct ReadContext { + const uint8_t *Start; + const uint8_t *Ptr; + const uint8_t *End; + }; + +private: + bool isValidFunctionIndex(uint32_t Index) const; + bool isDefinedFunctionIndex(uint32_t Index) const; + bool isValidGlobalIndex(uint32_t Index) const; + bool isDefinedGlobalIndex(uint32_t Index) const; + bool isValidEventIndex(uint32_t Index) const; + bool isDefinedEventIndex(uint32_t Index) const; + bool isValidFunctionSymbol(uint32_t Index) const; + bool isValidGlobalSymbol(uint32_t Index) const; + bool isValidEventSymbol(uint32_t Index) const; + bool isValidDataSymbol(uint32_t Index) const; + bool isValidSectionSymbol(uint32_t Index) const; + wasm::WasmFunction &getDefinedFunction(uint32_t Index); + const wasm::WasmFunction &getDefinedFunction(uint32_t Index) const; + wasm::WasmGlobal &getDefinedGlobal(uint32_t Index); + wasm::WasmEvent &getDefinedEvent(uint32_t Index); + + const WasmSection &getWasmSection(DataRefImpl Ref) const; + const wasm::WasmRelocation &getWasmRelocation(DataRefImpl Ref) const; + + Error parseSection(WasmSection &Sec); + Error parseCustomSection(WasmSection &Sec, ReadContext &Ctx); + + // Standard section types + Error parseTypeSection(ReadContext &Ctx); + Error parseImportSection(ReadContext &Ctx); + Error parseFunctionSection(ReadContext &Ctx); + Error parseTableSection(ReadContext &Ctx); + Error parseMemorySection(ReadContext &Ctx); + Error parseGlobalSection(ReadContext &Ctx); + Error parseEventSection(ReadContext &Ctx); + Error parseExportSection(ReadContext &Ctx); + Error parseStartSection(ReadContext &Ctx); + Error parseElemSection(ReadContext &Ctx); + Error parseCodeSection(ReadContext &Ctx); + Error parseDataSection(ReadContext &Ctx); + Error parseDataCountSection(ReadContext &Ctx); + + // Custom section types + Error parseDylinkSection(ReadContext &Ctx); + Error parseNameSection(ReadContext &Ctx); + Error parseLinkingSection(ReadContext &Ctx); + Error parseLinkingSectionSymtab(ReadContext &Ctx); + Error parseLinkingSectionComdat(ReadContext &Ctx); + Error parseProducersSection(ReadContext &Ctx); + Error parseTargetFeaturesSection(ReadContext &Ctx); + Error parseRelocSection(StringRef Name, ReadContext &Ctx); + + wasm::WasmObjectHeader Header; + std::vector<WasmSection> Sections; + wasm::WasmDylinkInfo DylinkInfo; + wasm::WasmProducerInfo ProducerInfo; + std::vector<wasm::WasmFeatureEntry> TargetFeatures; + std::vector<wasm::WasmSignature> Signatures; + std::vector<uint32_t> FunctionTypes; + std::vector<wasm::WasmTable> Tables; + std::vector<wasm::WasmLimits> Memories; + std::vector<wasm::WasmGlobal> Globals; + std::vector<wasm::WasmEvent> Events; + std::vector<wasm::WasmImport> Imports; + std::vector<wasm::WasmExport> Exports; + std::vector<wasm::WasmElemSegment> ElemSegments; + std::vector<WasmSegment> DataSegments; + llvm::Optional<size_t> DataCount; + std::vector<wasm::WasmFunction> Functions; + std::vector<WasmSymbol> Symbols; + std::vector<wasm::WasmFunctionName> DebugNames; + uint32_t StartFunction = -1; + bool HasLinkingSection = false; + bool HasDylinkSection = false; + wasm::WasmLinkingData LinkingData; + uint32_t NumImportedGlobals = 0; + uint32_t NumImportedFunctions = 0; + uint32_t NumImportedEvents = 0; + uint32_t CodeSection = 0; + uint32_t DataSection = 0; + uint32_t GlobalSection = 0; + uint32_t EventSection = 0; +}; + +class WasmSectionOrderChecker { +public: + // We define orders for all core wasm sections and known custom sections. + enum : int { + // Sentinel, must be zero + WASM_SEC_ORDER_NONE = 0, + + // Core sections + WASM_SEC_ORDER_TYPE, + WASM_SEC_ORDER_IMPORT, + WASM_SEC_ORDER_FUNCTION, + WASM_SEC_ORDER_TABLE, + WASM_SEC_ORDER_MEMORY, + WASM_SEC_ORDER_GLOBAL, + WASM_SEC_ORDER_EVENT, + WASM_SEC_ORDER_EXPORT, + WASM_SEC_ORDER_START, + WASM_SEC_ORDER_ELEM, + WASM_SEC_ORDER_DATACOUNT, + WASM_SEC_ORDER_CODE, + WASM_SEC_ORDER_DATA, + + // Custom sections + // "dylink" should be the very first section in the module + WASM_SEC_ORDER_DYLINK, + // "linking" section requires DATA section in order to validate data symbols + WASM_SEC_ORDER_LINKING, + // Must come after "linking" section in order to validate reloc indexes. + WASM_SEC_ORDER_RELOC, + // "name" section must appear after DATA. Comes after "linking" to allow + // symbol table to set default function name. + WASM_SEC_ORDER_NAME, + // "producers" section must appear after "name" section. + WASM_SEC_ORDER_PRODUCERS, + // "target_features" section must appear after producers section + WASM_SEC_ORDER_TARGET_FEATURES, + + // Must be last + WASM_NUM_SEC_ORDERS + + }; + + // Sections that may or may not be present, but cannot be predecessors + static int DisallowedPredecessors[WASM_NUM_SEC_ORDERS][WASM_NUM_SEC_ORDERS]; + + bool isValidSectionOrder(unsigned ID, StringRef CustomSectionName = ""); + +private: + bool Seen[WASM_NUM_SEC_ORDERS] = {}; // Sections that have been seen already + + // Returns -1 for unknown sections. + int getSectionOrder(unsigned ID, StringRef CustomSectionName = ""); +}; + +} // end namespace object + +inline raw_ostream &operator<<(raw_ostream &OS, const object::WasmSymbol &Sym) { + Sym.print(OS); + return OS; +} + +} // end namespace llvm + +#endif // LLVM_OBJECT_WASM_H |