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
23 using namespace llvm;
24
25 // Only the address of this fragment is ever actually used.
26 static MCDummyFragment SentinelFragment(nullptr);
27
28 // Sentinel value for the absolute pseudo fragment.
29 MCFragment *MCSymbol::AbsolutePseudoFragment = &SentinelFragment;
30
operator new(size_t s,const StringMapEntry<bool> * Name,MCContext & Ctx)31 void *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
setVariableValue(const MCExpr * Value)48 void 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
print(raw_ostream & OS,const MCAsmInfo * MAI) const59 void 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)
dump() const85 LLVM_DUMP_METHOD void MCSymbol::dump() const {
86 dbgs() << *this;
87 }
88 #endif
89