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 80