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/ADT/StringRef.h" 12 #include "llvm/Config/llvm-config.h" 13 #include "llvm/MC/MCAsmInfo.h" 14 #include "llvm/MC/MCContext.h" 15 #include "llvm/MC/MCExpr.h" 16 #include "llvm/MC/MCFragment.h" 17 #include "llvm/Support/Compiler.h" 18 #include "llvm/Support/Debug.h" 19 #include "llvm/Support/ErrorHandling.h" 20 #include "llvm/Support/raw_ostream.h" 21 #include <cassert> 22 #include <cstddef> 23 24 using namespace llvm; 25 26 // Only the address of this fragment is ever actually used. 27 static MCDummyFragment SentinelFragment(nullptr); 28 29 // Sentinel value for the absolute pseudo fragment. 30 MCFragment *MCSymbol::AbsolutePseudoFragment = &SentinelFragment; 31 32 void *MCSymbol::operator new(size_t s, const StringMapEntry<bool> *Name, 33 MCContext &Ctx) { 34 // We may need more space for a Name to account for alignment. So allocate 35 // space for the storage type and not the name pointer. 36 size_t Size = s + (Name ? sizeof(NameEntryStorageTy) : 0); 37 38 // For safety, ensure that the alignment of a pointer is enough for an 39 // MCSymbol. This also ensures we don't need padding between the name and 40 // symbol. 41 static_assert((unsigned)alignof(MCSymbol) <= alignof(NameEntryStorageTy), 42 "Bad alignment of MCSymbol"); 43 void *Storage = Ctx.allocate(Size, alignof(NameEntryStorageTy)); 44 NameEntryStorageTy *Start = static_cast<NameEntryStorageTy*>(Storage); 45 NameEntryStorageTy *End = Start + (Name ? 1 : 0); 46 return End; 47 } 48 49 void MCSymbol::setVariableValue(const MCExpr *Value) { 50 assert(!IsUsed && "Cannot set a variable that has already been used."); 51 assert(Value && "Invalid variable value!"); 52 assert((SymbolContents == SymContentsUnset || 53 SymbolContents == SymContentsVariable) && 54 "Cannot give common/offset symbol a variable value"); 55 this->Value = Value; 56 SymbolContents = SymContentsVariable; 57 setUndefined(); 58 } 59 60 void MCSymbol::print(raw_ostream &OS, const MCAsmInfo *MAI) const { 61 // The name for this MCSymbol is required to be a valid target name. However, 62 // some targets support quoting names with funny characters. If the name 63 // contains a funny character, then print it quoted. 64 StringRef Name = getName(); 65 if (!MAI || MAI->isValidUnquotedName(Name)) { 66 OS << Name; 67 return; 68 } 69 70 if (MAI && !MAI->supportsNameQuoting()) 71 report_fatal_error("Symbol name with unsupported characters"); 72 73 OS << '"'; 74 for (char C : Name) { 75 if (C == '\n') 76 OS << "\\n"; 77 else if (C == '"') 78 OS << "\\\""; 79 else 80 OS << C; 81 } 82 OS << '"'; 83 } 84 85 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP) 86 LLVM_DUMP_METHOD void MCSymbol::dump() const { 87 dbgs() << *this; 88 } 89 #endif 90