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
operator new(size_t s,const MCSymbolTableEntry * Name,MCContext & Ctx)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
setVariableValue(const MCExpr * Value)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
print(raw_ostream & OS,const MCAsmInfo * MAI) const56 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)
dump() const84 LLVM_DUMP_METHOD void MCSymbol::dump() const {
85 dbgs() << *this;
86 }
87 #endif
88