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