1 //===- lib/MC/MCSymbol.cpp - MCSymbol implementation ----------------------===// 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 #include "llvm/MC/MCSymbol.h" 11 #include "llvm/MC/MCExpr.h" 12 #include "llvm/Support/Debug.h" 13 #include "llvm/Support/raw_ostream.h" 14 using namespace llvm; 15 16 // Sentinel value for the absolute pseudo section. 17 const MCSection *MCSymbol::AbsolutePseudoSection = 18 reinterpret_cast<const MCSection *>(1); 19 20 static bool isAcceptableChar(char C) { 21 if ((C < 'a' || C > 'z') && 22 (C < 'A' || C > 'Z') && 23 (C < '0' || C > '9') && 24 C != '_' && C != '$' && C != '.' && C != '@') 25 return false; 26 return true; 27 } 28 29 /// NameNeedsQuoting - Return true if the identifier \p Str needs quotes to be 30 /// syntactically correct. 31 static bool NameNeedsQuoting(StringRef Str) { 32 assert(!Str.empty() && "Cannot create an empty MCSymbol"); 33 34 // If any of the characters in the string is an unacceptable character, force 35 // quotes. 36 for (unsigned i = 0, e = Str.size(); i != e; ++i) 37 if (!isAcceptableChar(Str[i])) 38 return true; 39 return false; 40 } 41 42 const MCSymbol &MCSymbol::AliasedSymbol() const { 43 const MCSymbol *S = this; 44 while (S->isVariable()) { 45 const MCExpr *Value = S->getVariableValue(); 46 if (Value->getKind() != MCExpr::SymbolRef) 47 return *S; 48 const MCSymbolRefExpr *Ref = static_cast<const MCSymbolRefExpr*>(Value); 49 S = &Ref->getSymbol(); 50 } 51 return *S; 52 } 53 54 void MCSymbol::setVariableValue(const MCExpr *Value) { 55 assert(!IsUsed && "Cannot set a variable that has already been used."); 56 assert(Value && "Invalid variable value!"); 57 this->Value = Value; 58 59 // Variables should always be marked as in the same "section" as the value. 60 const MCSection *Section = Value->FindAssociatedSection(); 61 if (Section) 62 setSection(*Section); 63 else 64 setUndefined(); 65 } 66 67 void MCSymbol::print(raw_ostream &OS) const { 68 // The name for this MCSymbol is required to be a valid target name. However, 69 // some targets support quoting names with funny characters. If the name 70 // contains a funny character, then print it quoted. 71 if (!NameNeedsQuoting(getName())) { 72 OS << getName(); 73 return; 74 } 75 76 OS << '"' << getName() << '"'; 77 } 78 79 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP) 80 void MCSymbol::dump() const { 81 print(dbgs()); 82 } 83 #endif 84
