MCAsmStreamer.cpp revision 71d259bc4be4f5c7a8a30c6be8da105074ff805a 
1//===- lib/MC/MCAsmStreamer.cpp - Text Assembly Output --------------------===//
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/MCStreamer.h"
11
12#include "llvm/MC/MCContext.h"
13#include "llvm/MC/MCSection.h"
14#include "llvm/MC/MCSymbol.h"
15#include "llvm/MC/MCValue.h"
16#include "llvm/Support/raw_ostream.h"
17using namespace llvm;
18
19namespace {
20
21  class MCAsmStreamer : public MCStreamer {
22    raw_ostream &OS;
23
24    MCSection *CurSection;
25
26  public:
27    MCAsmStreamer(MCContext &Context, raw_ostream &_OS)
28      : MCStreamer(Context), OS(_OS) {}
29    ~MCAsmStreamer() {}
30
31    /// @name MCStreamer Interface
32    /// @{
33
34    virtual void SwitchSection(MCSection *Section);
35
36    virtual void EmitLabel(MCSymbol *Symbol);
37
38    virtual void EmitAssignment(MCSymbol *Symbol, const MCValue &Value,
39                                bool MakeAbsolute = false);
40
41    virtual void EmitSymbolAttribute(MCSymbol *Symbol, SymbolAttr Attribute);
42
43    virtual void EmitBytes(const char *Data, unsigned Length);
44
45    virtual void EmitValue(const MCValue &Value, unsigned Size);
46
47    virtual void EmitInstruction(const MCInst &Inst);
48
49    virtual void Finish();
50
51    /// @}
52  };
53
54}
55
56/// Allow printing values directly to a raw_ostream.
57inline raw_ostream &operator<<(raw_ostream &os, const MCValue &Value) {
58  if (Value.getSymA()) {
59    os << Value.getSymA()->getName();
60    if (Value.getSymB())
61      os << " - " << Value.getSymB()->getName();
62    if (Value.getCst())
63      os << " + " << Value.getCst();
64  } else {
65    assert(!Value.getSymB() && "Invalid machine code value!");
66    os << Value.getCst();
67  }
68
69  return os;
70}
71
72void MCAsmStreamer::SwitchSection(MCSection *Section) {
73  if (Section != CurSection) {
74    CurSection = Section;
75
76    // FIXME: Really we would like the segment, flags, etc. to be separate
77    // values instead of embedded in the name. Not all assemblers understand all
78    // this stuff though.
79    OS << ".section " << Section->getName() << "\n";
80  }
81}
82
83void MCAsmStreamer::EmitLabel(MCSymbol *Symbol) {
84  assert(Symbol->getSection() == 0 && "Cannot emit a symbol twice!");
85  assert(CurSection && "Cannot emit before setting section!");
86  assert(!getContext().GetSymbolValue(Symbol) &&
87         "Cannot emit symbol which was directly assigned to!");
88
89  OS << Symbol->getName() << ":\n";
90  Symbol->setSection(CurSection);
91}
92
93void MCAsmStreamer::EmitAssignment(MCSymbol *Symbol, const MCValue &Value,
94                                   bool MakeAbsolute) {
95  assert(!Symbol->getSection() && "Cannot assign to a label!");
96
97  if (MakeAbsolute) {
98    OS << ".set " << Symbol->getName() << ", " << Value << '\n';
99  } else {
100    OS << Symbol->getName() << " = " << Value << '\n';
101  }
102
103  getContext().SetSymbolValue(Symbol, Value);
104}
105
106void MCAsmStreamer::EmitSymbolAttribute(MCSymbol *Symbol,
107                                        SymbolAttr Attribute) {
108  switch (Attribute) {
109  case Global: OS << ".globl"; break;
110  case Hidden: OS << ".hidden"; break;
111  case IndirectSymbol: OS << ".indirect_symbol"; break;
112  case Internal: OS << ".internal"; break;
113  case LazyReference: OS << ".lazy_reference"; break;
114  case NoDeadStrip: OS << ".no_dead_strip"; break;
115  case PrivateExtern: OS << ".private_extern"; break;
116  case Protected: OS << ".protected"; break;
117  case Reference: OS << ".reference"; break;
118  case Weak: OS << ".weak"; break;
119  case WeakDefinition: OS << ".weak_definition"; break;
120  case WeakReference: OS << ".weak_reference"; break;
121  }
122
123  OS << ' ' << Symbol->getName() << '\n';
124}
125
126void MCAsmStreamer::EmitBytes(const char *Data, unsigned Length) {
127  assert(CurSection && "Cannot emit contents before setting section!");
128  for (unsigned i = 0; i != Length; ++i)
129    OS << ".byte " << (unsigned) Data[i] << '\n';
130}
131
132void MCAsmStreamer::EmitValue(const MCValue &Value, unsigned Size) {
133  assert(CurSection && "Cannot emit contents before setting section!");
134  // Need target hooks to know how to print this.
135  switch (Size) {
136  default:
137    assert(0 && "Invalid size for machine code value!");
138  case 1: OS << ".byte"; break;
139  case 2: OS << ".short"; break;
140  case 4: OS << ".long"; break;
141  case 8: OS << ".quad"; break;
142  }
143
144  OS << ' ' << Value << '\n';
145}
146
147void MCAsmStreamer::EmitInstruction(const MCInst &Inst) {
148  assert(CurSection && "Cannot emit contents before setting section!");
149  // FIXME: Implement.
150  OS << "# FIXME: Implement instruction printing!\n";
151}
152
153void MCAsmStreamer::Finish() {
154  OS.flush();
155}
156
157MCStreamer *llvm::createAsmStreamer(MCContext &Context, raw_ostream &OS) {
158  return new MCAsmStreamer(Context, OS);
159}
160