LLVM 19.0.0git
MCSection.cpp
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1//===- lib/MC/MCSection.cpp - Machine Code Section Representation ---------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8
9#include "llvm/MC/MCSection.h"
10#include "llvm/ADT/STLExtras.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"
19#include <utility>
20
21using namespace llvm;
22
24 MCSymbol *Begin)
25 : Begin(Begin), BundleGroupBeforeFirstInst(false), HasInstructions(false),
26 IsRegistered(false), DummyFragment(this), Name(Name), Variant(V),
27 Kind(K) {}
28
30 if (!End)
31 End = Ctx.createTempSymbol("sec_end");
32 return End;
33}
34
35bool MCSection::hasEnded() const { return End && End->isInSection(); }
36
37MCSection::~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 SubsectionFragmentMap, 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.
80 SubsectionFragmentMap.insert(MI, std::make_pair(Subsection, F));
82 F->setParent(this);
83 F->setSubsectionNumber(Subsection);
84 }
85
86 return IP;
87}
88
89StringRef MCSection::getVirtualSectionKind() const { return "virtual"; }
90
91void MCSection::addPendingLabel(MCSymbol *label, unsigned Subsection) {
92 PendingLabels.push_back(PendingLabel(label, Subsection));
93}
94
96 unsigned Subsection) {
97 // Set the fragment and fragment offset for all pending symbols in the
98 // specified Subsection, and remove those symbols from the pending list.
99 for (auto It = PendingLabels.begin(); It != PendingLabels.end(); ++It) {
100 PendingLabel& Label = *It;
101 if (Label.Subsection == Subsection) {
102 Label.Sym->setFragment(F);
103 Label.Sym->setOffset(FOffset);
104 PendingLabels.erase(It--);
105 }
106 }
107}
108
110 // Make sure all remaining pending labels point to data fragments, by
111 // creating new empty data fragments for each Subsection with labels pending.
112 while (!PendingLabels.empty()) {
113 PendingLabel& Label = PendingLabels[0];
114 iterator CurInsertionPoint =
115 this->getSubsectionInsertionPoint(Label.Subsection);
116 const MCSymbol *Atom = nullptr;
117 if (CurInsertionPoint != begin())
118 Atom = std::prev(CurInsertionPoint)->getAtom();
119 MCFragment *F = new MCDataFragment();
120 getFragmentList().insert(CurInsertionPoint, F);
121 F->setParent(this);
122 F->setAtom(Atom);
123 flushPendingLabels(F, 0, Label.Subsection);
124 }
125}
126
127#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
129 raw_ostream &OS = errs();
130
131 OS << "<MCSection";
132 OS << " Fragments:[\n ";
133 for (auto it = begin(), ie = end(); it != ie; ++it) {
134 if (it != begin())
135 OS << ",\n ";
136 it->dump();
137 }
138 OS << "]>";
139}
140#endif
#define LLVM_DUMP_METHOD
Mark debug helper function definitions like dump() that should not be stripped from debug builds.
Definition: Compiler.h:529
std::string Name
IRTranslator LLVM IR MI
#define F(x, y, z)
Definition: MD5.cpp:55
This file contains some templates that are useful if you are working with the STL at all.
raw_pwrite_stream & OS
This file defines the SmallVector class.
Context object for machine code objects.
Definition: MCContext.h:76
MCSymbol * createTempSymbol()
Create a temporary symbol with a unique name.
Definition: MCContext.cpp:321
Fragment for data and encoded instructions.
Definition: MCFragment.h:242
void addPendingLabel(MCSymbol *label, unsigned Subsection=0)
Add a pending label for the requested subsection.
Definition: MCSection.cpp:91
virtual StringRef getVirtualSectionKind() const
Definition: MCSection.cpp:89
void dump() const
Definition: MCSection.cpp:128
void flushPendingLabels()
Associate all pending labels with empty data fragments.
Definition: MCSection.cpp:109
MCSection::FragmentListType & getFragmentList()
Definition: MCSection.h:172
MCSymbol * getEndSymbol(MCContext &Ctx)
Definition: MCSection.cpp:29
void setBundleLockState(BundleLockStateType NewState)
Definition: MCSection.cpp:39
iterator end()
Definition: MCSection.h:188
MCSection::iterator getSubsectionInsertionPoint(unsigned Subsection)
Definition: MCSection.cpp:59
bool hasEnded() const
Definition: MCSection.cpp:35
MCSection(SectionVariant V, StringRef Name, SectionKind K, MCSymbol *Begin)
Definition: MCSection.cpp:23
BundleLockStateType
Express the state of bundle locked groups while emitting code.
Definition: MCSection.h:55
@ BundleLockedAlignToEnd
Definition: MCSection.h:58
FragmentListType::iterator iterator
Definition: MCSection.h:64
iterator begin()
Definition: MCSection.h:185
MCSymbol - Instances of this class represent a symbol name in the MC file, and MCSymbols are created ...
Definition: MCSymbol.h:40
bool isInSection() const
isInSection - Check if this symbol is defined in some section (i.e., it is defined but not absolute).
Definition: MCSymbol.h:254
SectionKind - This is a simple POD value that classifies the properties of a section.
Definition: SectionKind.h:22
bool empty() const
Definition: SmallVector.h:94
This class consists of common code factored out of the SmallVector class to reduce code duplication b...
Definition: SmallVector.h:586
iterator erase(const_iterator CI)
Definition: SmallVector.h:750
void push_back(const T &Elt)
Definition: SmallVector.h:426
StringRef - Represent a constant reference to a string, i.e.
Definition: StringRef.h:50
iterator insert(iterator where, pointer New)
Definition: ilist.h:165
This class implements an extremely fast bulk output stream that can only output to a stream.
Definition: raw_ostream.h:52
This is an optimization pass for GlobalISel generic memory operations.
Definition: AddressRanges.h:18
void report_fatal_error(Error Err, bool gen_crash_diag=true)
Report a serious error, calling any installed error handler.
Definition: Error.cpp:156
raw_fd_ostream & errs()
This returns a reference to a raw_ostream for standard error.
auto lower_bound(R &&Range, T &&Value)
Provide wrappers to std::lower_bound which take ranges instead of having to pass begin/end explicitly...
Definition: STLExtras.h:1963