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Diffstat (limited to 'llvm/lib/Object/RecordStreamer.h')
-rw-r--r-- | llvm/lib/Object/RecordStreamer.h | 86 |
1 files changed, 86 insertions, 0 deletions
diff --git a/llvm/lib/Object/RecordStreamer.h b/llvm/lib/Object/RecordStreamer.h new file mode 100644 index 000000000000..c8b75bcc6d1d --- /dev/null +++ b/llvm/lib/Object/RecordStreamer.h @@ -0,0 +1,86 @@ +//===- RecordStreamer.h - Record asm defined and used symbols ---*- 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 +// +//===----------------------------------------------------------------------===// + +#ifndef LLVM_LIB_OBJECT_RECORDSTREAMER_H +#define LLVM_LIB_OBJECT_RECORDSTREAMER_H + +#include "llvm/ADT/DenseMap.h" +#include "llvm/ADT/StringMap.h" +#include "llvm/MC/MCDirectives.h" +#include "llvm/MC/MCStreamer.h" +#include "llvm/MC/MCSymbol.h" +#include "llvm/Support/SMLoc.h" +#include <vector> + +namespace llvm { + +class GlobalValue; +class Module; + +class RecordStreamer : public MCStreamer { +public: + enum State { NeverSeen, Global, Defined, DefinedGlobal, DefinedWeak, Used, + UndefinedWeak}; + +private: + const Module &M; + StringMap<State> Symbols; + // Map of aliases created by .symver directives, saved so we can update + // their symbol binding after parsing complete. This maps from each + // aliasee to its list of aliases. + DenseMap<const MCSymbol *, std::vector<StringRef>> SymverAliasMap; + + /// Get the state recorded for the given symbol. + State getSymbolState(const MCSymbol *Sym); + + void markDefined(const MCSymbol &Symbol); + void markGlobal(const MCSymbol &Symbol, MCSymbolAttr Attribute); + void markUsed(const MCSymbol &Symbol); + void visitUsedSymbol(const MCSymbol &Sym) override; + +public: + RecordStreamer(MCContext &Context, const Module &M); + + void EmitInstruction(const MCInst &Inst, const MCSubtargetInfo &STI) override; + void EmitLabel(MCSymbol *Symbol, SMLoc Loc = SMLoc()) override; + void EmitAssignment(MCSymbol *Symbol, const MCExpr *Value) override; + bool EmitSymbolAttribute(MCSymbol *Symbol, MCSymbolAttr Attribute) override; + void EmitZerofill(MCSection *Section, MCSymbol *Symbol, uint64_t Size, + unsigned ByteAlignment, SMLoc Loc = SMLoc()) override; + void EmitCommonSymbol(MCSymbol *Symbol, uint64_t Size, + unsigned ByteAlignment) override; + + // Ignore COFF-specific directives; we do not need any information from them, + // but the default implementation of these methods crashes, so we override + // them with versions that do nothing. + void BeginCOFFSymbolDef(const MCSymbol *Symbol) override {} + void EmitCOFFSymbolStorageClass(int StorageClass) override {} + void EmitCOFFSymbolType(int Type) override {} + void EndCOFFSymbolDef() override {} + + /// Record .symver aliases for later processing. + void emitELFSymverDirective(StringRef AliasName, + const MCSymbol *Aliasee) override; + + // Emit ELF .symver aliases and ensure they have the same binding as the + // defined symbol they alias with. + void flushSymverDirectives(); + + // Symbols iterators + using const_iterator = StringMap<State>::const_iterator; + const_iterator begin(); + const_iterator end(); + + // SymverAliasMap iterators + using const_symver_iterator = decltype(SymverAliasMap)::const_iterator; + iterator_range<const_symver_iterator> symverAliases(); +}; + +} // end namespace llvm + +#endif // LLVM_LIB_OBJECT_RECORDSTREAMER_H |