MCStreamer.cpp revision 484291c27319668ad99cb87def000254357736fb 
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/MCStreamer.h"
11#include "llvm/MC/MCExpr.h"
12#include "llvm/MC/MCObjectWriter.h"
13#include "llvm/Support/ErrorHandling.h"
14#include "llvm/Support/raw_ostream.h"
15#include "llvm/ADT/SmallString.h"
16#include "llvm/ADT/Twine.h"
17#include <cstdlib>
18using namespace llvm;
19
20MCStreamer::MCStreamer(MCContext &Ctx) : Context(Ctx), CurSection(0),
21                                         PrevSection(0) {
22}
23
24MCStreamer::~MCStreamer() {
25}
26
27raw_ostream &MCStreamer::GetCommentOS() {
28  // By default, discard comments.
29  return nulls();
30}
31
32
33/// EmitIntValue - Special case of EmitValue that avoids the client having to
34/// pass in a MCExpr for constant integers.
35void MCStreamer::EmitIntValue(uint64_t Value, unsigned Size,
36                              unsigned AddrSpace) {
37  EmitValue(MCConstantExpr::Create(Value, getContext()), Size, AddrSpace);
38}
39
40// EmitULEB128Value - Special case of EmitValue that emits a ULEB128 of the
41// Value as the sequence of ULEB128 encoded bytes.
42void MCStreamer::EmitULEB128Value(uint64_t Value, unsigned AddrSpace) {
43  SmallString<32> Tmp;
44  raw_svector_ostream OS(Tmp);
45  MCObjectWriter::EncodeULEB128(Value, OS);
46  EmitBytes(OS.str(), AddrSpace);
47}
48
49// EmitSLEB128Value - Special case of EmitValue that emits a SLEB128 of the
50// Value as the sequence of ULEB128 encoded bytes.
51void MCStreamer::EmitSLEB128Value(int64_t Value, unsigned AddrSpace) {
52  SmallString<32> Tmp;
53  raw_svector_ostream OS(Tmp);
54  MCObjectWriter::EncodeSLEB128(Value, OS);
55  EmitBytes(OS.str(), AddrSpace);
56}
57
58void MCStreamer::EmitSymbolValue(const MCSymbol *Sym, unsigned Size,
59                                 unsigned AddrSpace) {
60  EmitValue(MCSymbolRefExpr::Create(Sym, getContext()), Size, AddrSpace);
61}
62
63/// EmitFill - Emit NumBytes bytes worth of the value specified by
64/// FillValue.  This implements directives such as '.space'.
65void MCStreamer::EmitFill(uint64_t NumBytes, uint8_t FillValue,
66                          unsigned AddrSpace) {
67  const MCExpr *E = MCConstantExpr::Create(FillValue, getContext());
68  for (uint64_t i = 0, e = NumBytes; i != e; ++i)
69    EmitValue(E, 1, AddrSpace);
70}
71
72/// EmitRawText - If this file is backed by an assembly streamer, this dumps
73/// the specified string in the output .s file.  This capability is
74/// indicated by the hasRawTextSupport() predicate.
75void MCStreamer::EmitRawText(StringRef String) {
76  errs() << "EmitRawText called on an MCStreamer that doesn't support it, "
77  " something must not be fully mc'ized\n";
78  abort();
79}
80
81void MCStreamer::EmitRawText(const Twine &T) {
82  SmallString<128> Str;
83  T.toVector(Str);
84  EmitRawText(Str.str());
85}
86