1//===- lib/MC/MCSection.cpp - Machine Code Section Representation ---------===//
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/MCSection.h"
11#include "llvm/MC/MCAssembler.h"
12#include "llvm/MC/MCAsmInfo.h"
13#include "llvm/MC/MCContext.h"
14#include "llvm/MC/MCSymbol.h"
15#include "llvm/Support/raw_ostream.h"
16using namespace llvm;
17
18//===----------------------------------------------------------------------===//
19// MCSection
20//===----------------------------------------------------------------------===//
21
22MCSection::MCSection(SectionVariant V, SectionKind K, MCSymbol *Begin)
23    : Begin(Begin), BundleGroupBeforeFirstInst(false), HasInstructions(false),
24      IsRegistered(false), DummyFragment(this), Variant(V), Kind(K) {}
25
26MCSymbol *MCSection::getEndSymbol(MCContext &Ctx) {
27  if (!End)
28    End = Ctx.createTempSymbol("sec_end", true);
29  return End;
30}
31
32bool MCSection::hasEnded() const { return End && End->isInSection(); }
33
34MCSection::~MCSection() {
35}
36
37void MCSection::setBundleLockState(BundleLockStateType NewState) {
38  if (NewState == NotBundleLocked) {
39    if (BundleLockNestingDepth == 0) {
40      report_fatal_error("Mismatched bundle_lock/unlock directives");
41    }
42    if (--BundleLockNestingDepth == 0) {
43      BundleLockState = NotBundleLocked;
44    }
45    return;
46  }
47
48  // If any of the directives is an align_to_end directive, the whole nested
49  // group is align_to_end. So don't downgrade from align_to_end to just locked.
50  if (BundleLockState != BundleLockedAlignToEnd) {
51    BundleLockState = NewState;
52  }
53  ++BundleLockNestingDepth;
54}
55
56MCSection::iterator
57MCSection::getSubsectionInsertionPoint(unsigned Subsection) {
58  if (Subsection == 0 && SubsectionFragmentMap.empty())
59    return end();
60
61  SmallVectorImpl<std::pair<unsigned, MCFragment *>>::iterator MI =
62      std::lower_bound(SubsectionFragmentMap.begin(),
63                       SubsectionFragmentMap.end(),
64                       std::make_pair(Subsection, (MCFragment *)nullptr));
65  bool ExactMatch = false;
66  if (MI != SubsectionFragmentMap.end()) {
67    ExactMatch = MI->first == Subsection;
68    if (ExactMatch)
69      ++MI;
70  }
71  iterator IP;
72  if (MI == SubsectionFragmentMap.end())
73    IP = end();
74  else
75    IP = MI->second->getIterator();
76  if (!ExactMatch && Subsection != 0) {
77    // The GNU as documentation claims that subsections have an alignment of 4,
78    // although this appears not to be the case.
79    MCFragment *F = new MCDataFragment();
80    SubsectionFragmentMap.insert(MI, std::make_pair(Subsection, F));
81    getFragmentList().insert(IP, F);
82    F->setParent(this);
83  }
84
85  return IP;
86}
87
88#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
89LLVM_DUMP_METHOD void MCSection::dump() {
90  raw_ostream &OS = llvm::errs();
91
92  OS << "<MCSection";
93  OS << " Fragments:[\n      ";
94  for (auto it = begin(), ie = end(); it != ie; ++it) {
95    if (it != begin())
96      OS << ",\n      ";
97    it->dump();
98  }
99  OS << "]>";
100}
101#endif
102
103MCSection::iterator MCSection::begin() { return Fragments.begin(); }
104
105MCSection::iterator MCSection::end() { return Fragments.end(); }
106
107MCSection::reverse_iterator MCSection::rbegin() { return Fragments.rbegin(); }
108
109MCSection::reverse_iterator MCSection::rend() { return Fragments.rend(); }
110