lib/Object/RecordStreamer.h

   1 //===- RecordStreamer.h - Record asm defined and used symbols ---*- C++ -*-===//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file is distributed under the University of Illinois Open Source
   6 // License. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9
  10 #ifndef LLVM_LIB_OBJECT_RECORDSTREAMER_H
  11 #define LLVM_LIB_OBJECT_RECORDSTREAMER_H
  12
  13 #include "llvm/ADT/DenseMap.h"
  14 #include "llvm/ADT/StringMap.h"
  15 #include "llvm/MC/MCDirectives.h"
  16 #include "llvm/MC/MCStreamer.h"
  17 #include "llvm/MC/MCSymbol.h"
  18 #include "llvm/Support/SMLoc.h"
  19 #include <vector>
  20
  21 namespace llvm {
  22
  23 class GlobalValue;
  24 class Module;
  25
  26 class RecordStreamer : public MCStreamer {
  27 public:
  28   enum State { NeverSeen, Global, Defined, DefinedGlobal, DefinedWeak, Used,
  29                UndefinedWeak};
  30
  31 private:
  32   const Module &M;
  33   StringMap<State> Symbols;
  34   // Map of aliases created by .symver directives, saved so we can update
  35   // their symbol binding after parsing complete. This maps from each
  36   // aliasee to its list of aliases.
  37   DenseMap<const MCSymbol *, std::vector<StringRef>> SymverAliasMap;
  38
  39   /// Get the state recorded for the given symbol.
  40   State getSymbolState(const MCSymbol *Sym);
  41
  42   void markDefined(const MCSymbol &Symbol);
  43   void markGlobal(const MCSymbol &Symbol, MCSymbolAttr Attribute);
  44   void markUsed(const MCSymbol &Symbol);
  45   void visitUsedSymbol(const MCSymbol &Sym) override;
  46
  47 public:
  48   RecordStreamer(MCContext &Context, const Module &M);
  49
  50   void EmitInstruction(const MCInst &Inst, const MCSubtargetInfo &STI,
  51                        bool) override;
  52   void EmitLabel(MCSymbol *Symbol, SMLoc Loc = SMLoc()) override;
  53   void EmitAssignment(MCSymbol *Symbol, const MCExpr *Value) override;
  54   bool EmitSymbolAttribute(MCSymbol *Symbol, MCSymbolAttr Attribute) override;
  55   void EmitZerofill(MCSection *Section, MCSymbol *Symbol, uint64_t Size,
  56                     unsigned ByteAlignment, SMLoc Loc = SMLoc()) override;
  57   void EmitCommonSymbol(MCSymbol *Symbol, uint64_t Size,
  58                         unsigned ByteAlignment) override;
  59   /// Record .symver aliases for later processing.
  60   void emitELFSymverDirective(StringRef AliasName,
  61                               const MCSymbol *Aliasee) override;
  62
  63   // Emit ELF .symver aliases and ensure they have the same binding as the
  64   // defined symbol they alias with.
  65   void flushSymverDirectives();
  66
  67   // Symbols iterators
  68   using const_iterator = StringMap<State>::const_iterator;
  69   const_iterator begin();
  70   const_iterator end();
  71
  72   // SymverAliasMap iterators
  73   using const_symver_iterator = decltype(SymverAliasMap)::const_iterator;
  74   iterator_range<const_symver_iterator> symverAliases();
  75 };
  76
  77 } // end namespace llvm
  78
  79 #endif // LLVM_LIB_OBJECT_RECORDSTREAMER_H