1 //===- lib/MC/MCSymbol.cpp - MCSymbol implementation ----------------------===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9
10 #include "llvm/MC/MCSymbol.h"
11 #include "llvm/MC/MCAsmInfo.h"
12 #include "llvm/MC/MCContext.h"
13 #include "llvm/MC/MCExpr.h"
14 #include "llvm/Support/Debug.h"
15 #include "llvm/Support/ErrorHandling.h"
16 #include "llvm/Support/raw_ostream.h"
17 using namespace llvm;
18
19 // Only the address of this fragment is ever actually used.
20 static MCDummyFragment SentinelFragment(nullptr);
21
22 // Sentinel value for the absolute pseudo fragment.
23 MCFragment *MCSymbol::AbsolutePseudoFragment = &SentinelFragment;
24
operator new(size_t s,const StringMapEntry<bool> * Name,MCContext & Ctx)25 void *MCSymbol::operator new(size_t s, const StringMapEntry<bool> *Name,
26 MCContext &Ctx) {
27 // We may need more space for a Name to account for alignment. So allocate
28 // space for the storage type and not the name pointer.
29 size_t Size = s + (Name ? sizeof(NameEntryStorageTy) : 0);
30
31 // For safety, ensure that the alignment of a pointer is enough for an
32 // MCSymbol. This also ensures we don't need padding between the name and
33 // symbol.
34 static_assert((unsigned)AlignOf<MCSymbol>::Alignment <=
35 AlignOf<NameEntryStorageTy>::Alignment,
36 "Bad alignment of MCSymbol");
37 void *Storage = Ctx.allocate(Size, alignOf<NameEntryStorageTy>());
38 NameEntryStorageTy *Start = static_cast<NameEntryStorageTy*>(Storage);
39 NameEntryStorageTy *End = Start + (Name ? 1 : 0);
40 return End;
41 }
42
setVariableValue(const MCExpr * Value)43 void MCSymbol::setVariableValue(const MCExpr *Value) {
44 assert(!IsUsed && "Cannot set a variable that has already been used.");
45 assert(Value && "Invalid variable value!");
46 assert((SymbolContents == SymContentsUnset ||
47 SymbolContents == SymContentsVariable) &&
48 "Cannot give common/offset symbol a variable value");
49 this->Value = Value;
50 SymbolContents = SymContentsVariable;
51 setUndefined();
52 }
53
print(raw_ostream & OS,const MCAsmInfo * MAI) const54 void MCSymbol::print(raw_ostream &OS, const MCAsmInfo *MAI) const {
55 // The name for this MCSymbol is required to be a valid target name. However,
56 // some targets support quoting names with funny characters. If the name
57 // contains a funny character, then print it quoted.
58 StringRef Name = getName();
59 if (!MAI || MAI->isValidUnquotedName(Name)) {
60 OS << Name;
61 return;
62 }
63
64 if (MAI && !MAI->supportsNameQuoting())
65 report_fatal_error("Symbol name with unsupported characters");
66
67 OS << '"';
68 for (char C : Name) {
69 if (C == '\n')
70 OS << "\\n";
71 else if (C == '"')
72 OS << "\\\"";
73 else
74 OS << C;
75 }
76 OS << '"';
77 }
78
79 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
dump() const80 LLVM_DUMP_METHOD void MCSymbol::dump() const { dbgs() << *this; }
81 #endif
82