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/MCAsmInfo.h" 12 #include "llvm/MC/MCContext.h" 13 #include "llvm/MC/MCExpr.h" 14 #include "llvm/Support/Debug.h" 15 #include "llvm/Support/ErrorHandling.h" 16 #include "llvm/Support/raw_ostream.h" 17 using namespace llvm; 18 19 // Only the address of this fragment is ever actually used. 20 static MCDummyFragment SentinelFragment(nullptr); 21 22 // Sentinel value for the absolute pseudo fragment. 23 MCFragment *MCSymbol::AbsolutePseudoFragment = &SentinelFragment; 24 25 void *MCSymbol::operator new(size_t s, const StringMapEntry<bool> *Name, 26 MCContext &Ctx) { 27 // We may need more space for a Name to account for alignment. So allocate 28 // space for the storage type and not the name pointer. 29 size_t Size = s + (Name ? sizeof(NameEntryStorageTy) : 0); 30 31 // For safety, ensure that the alignment of a pointer is enough for an 32 // MCSymbol. This also ensures we don't need padding between the name and 33 // symbol. 34 static_assert((unsigned)alignof(MCSymbol) <= alignof(NameEntryStorageTy), 35 "Bad alignment of MCSymbol"); 36 void *Storage = Ctx.allocate(Size, alignof(NameEntryStorageTy)); 37 NameEntryStorageTy *Start = static_cast<NameEntryStorageTy*>(Storage); 38 NameEntryStorageTy *End = Start + (Name ? 1 : 0); 39 return End; 40 } 41 42 void MCSymbol::setVariableValue(const MCExpr *Value) { 43 assert(!IsUsed && "Cannot set a variable that has already been used."); 44 assert(Value && "Invalid variable value!"); 45 assert((SymbolContents == SymContentsUnset || 46 SymbolContents == SymContentsVariable) && 47 "Cannot give common/offset symbol a variable value"); 48 this->Value = Value; 49 SymbolContents = SymContentsVariable; 50 setUndefined(); 51 } 52 53 void MCSymbol::print(raw_ostream &OS, const MCAsmInfo *MAI) const { 54 // The name for this MCSymbol is required to be a valid target name. However, 55 // some targets support quoting names with funny characters. If the name 56 // contains a funny character, then print it quoted. 57 StringRef Name = getName(); 58 if (!MAI || MAI->isValidUnquotedName(Name)) { 59 OS << Name; 60 return; 61 } 62 63 if (MAI && !MAI->supportsNameQuoting()) 64 report_fatal_error("Symbol name with unsupported characters"); 65 66 OS << '"'; 67 for (char C : Name) { 68 if (C == '\n') 69 OS << "\\n"; 70 else if (C == '"') 71 OS << "\\\""; 72 else 73 OS << C; 74 } 75 OS << '"'; 76 } 77 78 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP) 79 LLVM_DUMP_METHOD void MCSymbol::dump() const { 80 dbgs() << *this; 81 } 82 #endif 83