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"
16 using namespace llvm;
17
18 //===----------------------------------------------------------------------===//
19 // MCSection
20 //===----------------------------------------------------------------------===//
21
MCSection(SectionVariant V,SectionKind K,MCSymbol * Begin)22 MCSection::MCSection(SectionVariant V, SectionKind K, MCSymbol *Begin)
23 : Begin(Begin), BundleGroupBeforeFirstInst(false), HasInstructions(false),
24 IsRegistered(false), DummyFragment(this), Variant(V), Kind(K) {}
25
getEndSymbol(MCContext & Ctx)26 MCSymbol *MCSection::getEndSymbol(MCContext &Ctx) {
27 if (!End)
28 End = Ctx.createTempSymbol("sec_end", true);
29 return End;
30 }
31
hasEnded() const32 bool MCSection::hasEnded() const { return End && End->isInSection(); }
33
~MCSection()34 MCSection::~MCSection() {
35 }
36
setBundleLockState(BundleLockStateType NewState)37 void 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
56 MCSection::iterator
getSubsectionInsertionPoint(unsigned Subsection)57 MCSection::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)
dump()89 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
begin()103 MCSection::iterator MCSection::begin() { return Fragments.begin(); }
104
end()105 MCSection::iterator MCSection::end() { return Fragments.end(); }
106
rbegin()107 MCSection::reverse_iterator MCSection::rbegin() { return Fragments.rbegin(); }
108
rend()109 MCSection::reverse_iterator MCSection::rend() { return Fragments.rend(); }
110