1 //===- lib/MC/MCSymbol.cpp - MCSymbol implementation ----------------------===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 9 #include "llvm/MC/MCSymbol.h" 10 #include "llvm/ADT/StringRef.h" 11 #include "llvm/Config/llvm-config.h" 12 #include "llvm/MC/MCAsmInfo.h" 13 #include "llvm/MC/MCContext.h" 14 #include "llvm/Support/Compiler.h" 15 #include "llvm/Support/Debug.h" 16 #include "llvm/Support/ErrorHandling.h" 17 #include "llvm/Support/raw_ostream.h" 18 #include <cassert> 19 #include <cstddef> 20 21 using namespace llvm; 22 23 // Only the address of this fragment is ever actually used. 24 static MCDataFragment SentinelFragment; 25 26 // Sentinel value for the absolute pseudo fragment. 27 MCFragment *MCSymbol::AbsolutePseudoFragment = &SentinelFragment; 28 29 void *MCSymbol::operator new(size_t s, const MCSymbolTableEntry *Name, 30 MCContext &Ctx) { 31 // We may need more space for a Name to account for alignment. So allocate 32 // space for the storage type and not the name pointer. 33 size_t Size = s + (Name ? sizeof(NameEntryStorageTy) : 0); 34 35 // For safety, ensure that the alignment of a pointer is enough for an 36 // MCSymbol. This also ensures we don't need padding between the name and 37 // symbol. 38 static_assert((unsigned)alignof(MCSymbol) <= alignof(NameEntryStorageTy), 39 "Bad alignment of MCSymbol"); 40 void *Storage = Ctx.allocate(Size, alignof(NameEntryStorageTy)); 41 NameEntryStorageTy *Start = static_cast<NameEntryStorageTy*>(Storage); 42 NameEntryStorageTy *End = Start + (Name ? 1 : 0); 43 return End; 44 } 45 46 void MCSymbol::setVariableValue(const MCExpr *Value) { 47 assert(Value && "Invalid variable value!"); 48 assert((SymbolContents == SymContentsUnset || 49 SymbolContents == SymContentsVariable) && 50 "Cannot give common/offset symbol a variable value"); 51 this->Value = Value; 52 SymbolContents = SymContentsVariable; 53 setUndefined(); 54 } 55 56 void MCSymbol::print(raw_ostream &OS, const MCAsmInfo *MAI) const { 57 // The name for this MCSymbol is required to be a valid target name. However, 58 // some targets support quoting names with funny characters. If the name 59 // contains a funny character, then print it quoted. 60 StringRef Name = getName(); 61 if (!MAI || MAI->isValidUnquotedName(Name)) { 62 OS << Name; 63 return; 64 } 65 66 if (MAI && !MAI->supportsNameQuoting()) 67 report_fatal_error("Symbol name with unsupported characters"); 68 69 OS << '"'; 70 for (char C : Name) { 71 if (C == '\n') 72 OS << "\\n"; 73 else if (C == '"') 74 OS << "\\\""; 75 else if (C == '\\') 76 OS << "\\\\"; 77 else 78 OS << C; 79 } 80 OS << '"'; 81 } 82 83 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP) 84 LLVM_DUMP_METHOD void MCSymbol::dump() const { 85 dbgs() << *this; 86 } 87 #endif 88