MCStreamer.cpp revision 32a006e606742b1c5401e49607e33717bb5441f0 
1//===- lib/MC/MCStreamer.cpp - Streaming Machine Code 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/MCContext.h"
11#include "llvm/MC/MCStreamer.h"
12#include "llvm/MC/MCExpr.h"
13#include "llvm/MC/MCObjectWriter.h"
14#include "llvm/Support/ErrorHandling.h"
15#include "llvm/Support/raw_ostream.h"
16#include "llvm/ADT/SmallString.h"
17#include "llvm/ADT/Twine.h"
18#include <cstdlib>
19using namespace llvm;
20
21MCStreamer::MCStreamer(MCContext &Ctx) : Context(Ctx), CurSection(0),
22                                         PrevSection(0) {
23}
24
25MCStreamer::~MCStreamer() {
26}
27
28raw_ostream &MCStreamer::GetCommentOS() {
29  // By default, discard comments.
30  return nulls();
31}
32
33void MCStreamer::EmitDwarfSetLineAddr(int64_t LineDelta,
34                                      const MCSymbol *Label, int PointerSize) {
35  // emit the sequence to set the address
36  EmitIntValue(dwarf::DW_LNS_extended_op, 1);
37  EmitULEB128IntValue(PointerSize + 1);
38  EmitIntValue(dwarf::DW_LNE_set_address, 1);
39  EmitSymbolValue(Label, PointerSize);
40
41  // emit the sequence for the LineDelta (from 1) and a zero address delta.
42  MCDwarfLineAddr::Emit(this, LineDelta, 0);
43}
44
45/// EmitIntValue - Special case of EmitValue that avoids the client having to
46/// pass in a MCExpr for constant integers.
47void MCStreamer::EmitIntValue(uint64_t Value, unsigned Size,
48                              unsigned AddrSpace) {
49  EmitValue(MCConstantExpr::Create(Value, getContext()), Size, AddrSpace);
50}
51
52/// EmitULEB128Value - Special case of EmitULEB128Value that avoids the
53/// client having to pass in a MCExpr for constant integers.
54void MCStreamer::EmitULEB128IntValue(uint64_t Value, unsigned AddrSpace) {
55  EmitULEB128Value(MCConstantExpr::Create(Value, getContext()), AddrSpace);
56}
57
58/// EmitSLEB128Value - Special case of EmitSLEB128Value that avoids the
59/// client having to pass in a MCExpr for constant integers.
60void MCStreamer::EmitSLEB128IntValue(int64_t Value, unsigned AddrSpace) {
61  EmitSLEB128Value(MCConstantExpr::Create(Value, getContext()), AddrSpace);
62}
63
64void MCStreamer::EmitSymbolValue(const MCSymbol *Sym, unsigned Size,
65                                 unsigned AddrSpace) {
66  EmitValue(MCSymbolRefExpr::Create(Sym, getContext()), Size, AddrSpace);
67}
68
69void MCStreamer::EmitGPRel32Value(const MCExpr *Value) {
70  report_fatal_error("unsupported directive in streamer");
71}
72
73/// EmitFill - Emit NumBytes bytes worth of the value specified by
74/// FillValue.  This implements directives such as '.space'.
75void MCStreamer::EmitFill(uint64_t NumBytes, uint8_t FillValue,
76                          unsigned AddrSpace) {
77  const MCExpr *E = MCConstantExpr::Create(FillValue, getContext());
78  for (uint64_t i = 0, e = NumBytes; i != e; ++i)
79    EmitValue(E, 1, AddrSpace);
80}
81
82bool MCStreamer::EmitDwarfFileDirective(unsigned FileNo,
83                                        StringRef Filename) {
84  return getContext().GetDwarfFile(Filename, FileNo) == 0;
85}
86
87void MCStreamer::EmitDwarfLocDirective(unsigned FileNo, unsigned Line,
88                                       unsigned Column, unsigned Flags,
89                                       unsigned Isa,
90                                       unsigned Discriminator) {
91  getContext().setCurrentDwarfLoc(FileNo, Line, Column, Flags, Isa,
92                                  Discriminator);
93}
94
95bool MCStreamer::EmitCFIStartProc() {
96  return false;
97}
98
99bool MCStreamer::EmitCFIEndProc() {
100  return false;
101}
102
103bool MCStreamer::EmitCFIDefCfaOffset(int64_t Offset) {
104  return false;
105}
106
107bool MCStreamer::EmitCFIDefCfaRegister(int64_t Register) {
108  return false;
109}
110
111bool MCStreamer::EmitCFIOffset(int64_t Register, int64_t Offset) {
112  return false;
113}
114
115bool MCStreamer::EmitCFIPersonality(const MCSymbol *Sym) {
116  return false;
117}
118
119bool MCStreamer::EmitCFILsda(const MCSymbol *Sym) {
120  return false;
121}
122
123/// EmitRawText - If this file is backed by an assembly streamer, this dumps
124/// the specified string in the output .s file.  This capability is
125/// indicated by the hasRawTextSupport() predicate.
126void MCStreamer::EmitRawText(StringRef String) {
127  errs() << "EmitRawText called on an MCStreamer that doesn't support it, "
128  " something must not be fully mc'ized\n";
129  abort();
130}
131
132void MCStreamer::EmitRawText(const Twine &T) {
133  SmallString<128> Str;
134  T.toVector(Str);
135  EmitRawText(Str.str());
136}
137