MCStreamer.cpp revision af6b5808756d6ce335df9eb158efa33894b401c4 
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
33
34/// EmitIntValue - Special case of EmitValue that avoids the client having to
35/// pass in a MCExpr for constant integers.
36void MCStreamer::EmitIntValue(uint64_t Value, unsigned Size,
37                              unsigned AddrSpace) {
38  EmitValue(MCConstantExpr::Create(Value, getContext()), Size, AddrSpace);
39}
40
41/// EmitULEB128Value - Special case of EmitULEB128Value that avoids the
42/// client having to pass in a MCExpr for constant integers.
43void MCStreamer::EmitULEB128IntValue(uint64_t Value, unsigned AddrSpace) {
44  EmitULEB128Value(MCConstantExpr::Create(Value, getContext()), AddrSpace);
45}
46
47/// EmitSLEB128Value - Special case of EmitSLEB128Value that avoids the
48/// client having to pass in a MCExpr for constant integers.
49void MCStreamer::EmitSLEB128IntValue(int64_t Value, unsigned AddrSpace) {
50  EmitSLEB128Value(MCConstantExpr::Create(Value, getContext()), AddrSpace);
51}
52
53void MCStreamer::EmitSymbolValue(const MCSymbol *Sym, unsigned Size,
54                                 unsigned AddrSpace) {
55  EmitValue(MCSymbolRefExpr::Create(Sym, getContext()), Size, AddrSpace);
56}
57
58/// EmitFill - Emit NumBytes bytes worth of the value specified by
59/// FillValue.  This implements directives such as '.space'.
60void MCStreamer::EmitFill(uint64_t NumBytes, uint8_t FillValue,
61                          unsigned AddrSpace) {
62  const MCExpr *E = MCConstantExpr::Create(FillValue, getContext());
63  for (uint64_t i = 0, e = NumBytes; i != e; ++i)
64    EmitValue(E, 1, AddrSpace);
65}
66
67bool MCStreamer::EmitDwarfFileDirective(unsigned FileNo,
68                                        StringRef Filename) {
69  return getContext().GetDwarfFile(Filename, FileNo) == 0;
70}
71
72void MCStreamer::EmitDwarfLocDirective(unsigned FileNo, unsigned Line,
73                                       unsigned Column, unsigned Flags,
74                                       unsigned Isa,
75                                       unsigned Discriminator) {
76  getContext().setCurrentDwarfLoc(FileNo, Line, Column, Flags, Isa,
77                                  Discriminator);
78}
79
80/// EmitRawText - If this file is backed by an assembly streamer, this dumps
81/// the specified string in the output .s file.  This capability is
82/// indicated by the hasRawTextSupport() predicate.
83void MCStreamer::EmitRawText(StringRef String) {
84  errs() << "EmitRawText called on an MCStreamer that doesn't support it, "
85  " something must not be fully mc'ized\n";
86  abort();
87}
88
89void MCStreamer::EmitRawText(const Twine &T) {
90  SmallString<128> Str;
91  T.toVector(Str);
92  EmitRawText(Str.str());
93}
94