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