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/ADT/StringRef.h"
12 #include "llvm/Config/llvm-config.h"
13 #include "llvm/MC/MCAsmInfo.h"
14 #include "llvm/MC/MCContext.h"
15 #include "llvm/MC/MCExpr.h"
16 #include "llvm/MC/MCFragment.h"
17 #include "llvm/Support/Compiler.h"
18 #include "llvm/Support/Debug.h"
19 #include "llvm/Support/ErrorHandling.h"
20 #include "llvm/Support/raw_ostream.h"
21 #include <cassert>
22 #include <cstddef>
23
24 using namespace llvm;
25
26 // Only the address of this fragment is ever actually used.
27 static MCDummyFragment SentinelFragment(nullptr);
28
29 // Sentinel value for the absolute pseudo fragment.
30 MCFragment *MCSymbol::AbsolutePseudoFragment = &SentinelFragment;
31
operator new(size_t s,const StringMapEntry<bool> * Name,MCContext & Ctx)32 void *MCSymbol::operator new(size_t s, const StringMapEntry<bool> *Name,
33 MCContext &Ctx) {
34 // We may need more space for a Name to account for alignment. So allocate
35 // space for the storage type and not the name pointer.
36 size_t Size = s + (Name ? sizeof(NameEntryStorageTy) : 0);
37
38 // For safety, ensure that the alignment of a pointer is enough for an
39 // MCSymbol. This also ensures we don't need padding between the name and
40 // symbol.
41 static_assert((unsigned)alignof(MCSymbol) <= alignof(NameEntryStorageTy),
42 "Bad alignment of MCSymbol");
43 void *Storage = Ctx.allocate(Size, alignof(NameEntryStorageTy));
44 NameEntryStorageTy *Start = static_cast<NameEntryStorageTy*>(Storage);
45 NameEntryStorageTy *End = Start + (Name ? 1 : 0);
46 return End;
47 }
48
setVariableValue(const MCExpr * Value)49 void MCSymbol::setVariableValue(const MCExpr *Value) {
50 assert(!IsUsed && "Cannot set a variable that has already been used.");
51 assert(Value && "Invalid variable value!");
52 assert((SymbolContents == SymContentsUnset ||
53 SymbolContents == SymContentsVariable) &&
54 "Cannot give common/offset symbol a variable value");
55 this->Value = Value;
56 SymbolContents = SymContentsVariable;
57 setUndefined();
58 }
59
print(raw_ostream & OS,const MCAsmInfo * MAI) const60 void MCSymbol::print(raw_ostream &OS, const MCAsmInfo *MAI) const {
61 // The name for this MCSymbol is required to be a valid target name. However,
62 // some targets support quoting names with funny characters. If the name
63 // contains a funny character, then print it quoted.
64 StringRef Name = getName();
65 if (!MAI || MAI->isValidUnquotedName(Name)) {
66 OS << Name;
67 return;
68 }
69
70 if (MAI && !MAI->supportsNameQuoting())
71 report_fatal_error("Symbol name with unsupported characters");
72
73 OS << '"';
74 for (char C : Name) {
75 if (C == '\n')
76 OS << "\\n";
77 else if (C == '"')
78 OS << "\\\"";
79 else
80 OS << C;
81 }
82 OS << '"';
83 }
84
85 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
dump() const86 LLVM_DUMP_METHOD void MCSymbol::dump() const {
87 dbgs() << *this;
88 }
89 #endif
90