LLVM  8.0.0svn
MCSection.cpp
Go to the documentation of this file.
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/ADT/SmallVector.h"
12 #include "llvm/Config/llvm-config.h"
13 #include "llvm/MC/MCContext.h"
14 #include "llvm/MC/MCFragment.h"
15 #include "llvm/MC/MCSymbol.h"
16 #include "llvm/Support/Compiler.h"
19 #include <algorithm>
20 #include <utility>
21 
22 using namespace llvm;
23 
25  : Begin(Begin), BundleGroupBeforeFirstInst(false), HasInstructions(false),
26  HasData(false), IsRegistered(false), DummyFragment(this), Variant(V),
27  Kind(K) {}
28 
30  if (!End)
31  End = Ctx.createTempSymbol("sec_end", true);
32  return End;
33 }
34 
35 bool MCSection::hasEnded() const { return End && End->isInSection(); }
36 
37 MCSection::~MCSection() = default;
38 
40  if (NewState == NotBundleLocked) {
41  if (BundleLockNestingDepth == 0) {
42  report_fatal_error("Mismatched bundle_lock/unlock directives");
43  }
44  if (--BundleLockNestingDepth == 0) {
45  BundleLockState = NotBundleLocked;
46  }
47  return;
48  }
49 
50  // If any of the directives is an align_to_end directive, the whole nested
51  // group is align_to_end. So don't downgrade from align_to_end to just locked.
52  if (BundleLockState != BundleLockedAlignToEnd) {
53  BundleLockState = NewState;
54  }
55  ++BundleLockNestingDepth;
56 }
57 
60  if (Subsection == 0 && SubsectionFragmentMap.empty())
61  return end();
62 
64  std::lower_bound(SubsectionFragmentMap.begin(),
65  SubsectionFragmentMap.end(),
66  std::make_pair(Subsection, (MCFragment *)nullptr));
67  bool ExactMatch = false;
68  if (MI != SubsectionFragmentMap.end()) {
69  ExactMatch = MI->first == Subsection;
70  if (ExactMatch)
71  ++MI;
72  }
73  iterator IP;
74  if (MI == SubsectionFragmentMap.end())
75  IP = end();
76  else
77  IP = MI->second->getIterator();
78  if (!ExactMatch && Subsection != 0) {
79  // The GNU as documentation claims that subsections have an alignment of 4,
80  // although this appears not to be the case.
81  MCFragment *F = new MCDataFragment();
82  SubsectionFragmentMap.insert(MI, std::make_pair(Subsection, F));
83  getFragmentList().insert(IP, F);
84  F->setParent(this);
85  }
86 
87  return IP;
88 }
89 
90 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
92  raw_ostream &OS = errs();
93 
94  OS << "<MCSection";
95  OS << " Fragments:[\n ";
96  for (auto it = begin(), ie = end(); it != ie; ++it) {
97  if (it != begin())
98  OS << ",\n ";
99  it->dump();
100  }
101  OS << "]>";
102 }
103 #endif
raw_ostream & errs()
This returns a reference to a raw_ostream for standard error.
LLVM_ATTRIBUTE_NORETURN void report_fatal_error(Error Err, bool gen_crash_diag=true)
Report a serious error, calling any installed error handler.
Definition: Error.cpp:139
Compute iterated dominance frontiers using a linear time algorithm.
Definition: AllocatorList.h:24
MCSymbol - Instances of this class represent a symbol name in the MC file, and MCSymbols are created ...
Definition: MCSymbol.h:42
MCSection(SectionVariant V, SectionKind K, MCSymbol *Begin)
Definition: MCSection.cpp:24
void setBundleLockState(BundleLockStateType NewState)
Definition: MCSection.cpp:39
F(f)
void dump() const
Definition: MCSection.cpp:91
BundleLockStateType
Express the state of bundle locked groups while emitting code.
Definition: MCSection.h:44
This class consists of common code factored out of the SmallVector class to reduce code duplication b...
Definition: APFloat.h:42
bool isInSection() const
isInSection - Check if this symbol is defined in some section (i.e., it is defined but not absolute)...
Definition: MCSymbol.h:252
#define LLVM_DUMP_METHOD
Definition: Compiler.h:74
MCSymbol * getEndSymbol(MCContext &Ctx)
Definition: MCSection.cpp:29
Context object for machine code objects.
Definition: MCContext.h:63
bool hasEnded() const
Definition: MCSection.cpp:35
auto lower_bound(R &&Range, ForwardIt I) -> decltype(adl_begin(Range))
Provide wrappers to std::lower_bound which take ranges instead of having to pass begin/end explicitly...
Definition: STLExtras.h:1138
MCSymbol * createTempSymbol(bool CanBeUnnamed=true)
Create and return a new assembler temporary symbol with a unique but unspecified name.
Definition: MCContext.cpp:217
SectionKind - This is a simple POD value that classifies the properties of a section.
Definition: SectionKind.h:23
Iterator for intrusive lists based on ilist_node.
iterator insert(iterator where, pointer New)
Definition: ilist.h:228
const unsigned Kind
Fragment for data and encoded instructions.
Definition: MCFragment.h:242
MCSection::iterator getSubsectionInsertionPoint(unsigned Subsection)
Definition: MCSection.cpp:59
This class implements an extremely fast bulk output stream that can only output to a stream...
Definition: raw_ostream.h:46
IRTranslator LLVM IR MI
iterator end()
Definition: MCSection.h:166
void setParent(MCSection *Value)
Definition: MCFragment.h:100
MCSection::FragmentListType & getFragmentList()
Definition: MCSection.h:150
iterator begin()
Definition: MCSection.h:163