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"
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"
17 #include "llvm/Support/ErrorHandling.h"
18 #include "llvm/Support/raw_ostream.h"
19 #include <utility>
20
21 using namespace llvm;
22
MCSection(SectionVariant V,StringRef Name,bool IsText,bool IsVirtual,MCSymbol * Begin)23 MCSection::MCSection(SectionVariant V, StringRef Name, bool IsText,
24 bool IsVirtual, MCSymbol *Begin)
25 : Begin(Begin), BundleGroupBeforeFirstInst(false), HasInstructions(false),
26 HasLayout(false), IsRegistered(false), IsText(IsText),
27 IsVirtual(IsVirtual), Name(Name), Variant(V) {
28 DummyFragment.setParent(this);
29 // The initial subsection number is 0. Create a fragment list.
30 CurFragList = &Subsections.emplace_back(0u, FragList{}).second;
31 }
32
getEndSymbol(MCContext & Ctx)33 MCSymbol *MCSection::getEndSymbol(MCContext &Ctx) {
34 if (!End)
35 End = Ctx.createTempSymbol("sec_end");
36 return End;
37 }
38
hasEnded() const39 bool MCSection::hasEnded() const { return End && End->isInSection(); }
40
~MCSection()41 MCSection::~MCSection() {
42 for (auto &[_, Chain] : Subsections) {
43 for (MCFragment *X = Chain.Head, *Y; X; X = Y) {
44 Y = X->Next;
45 X->destroy();
46 }
47 }
48 }
49
setBundleLockState(BundleLockStateType NewState)50 void MCSection::setBundleLockState(BundleLockStateType NewState) {
51 if (NewState == NotBundleLocked) {
52 if (BundleLockNestingDepth == 0) {
53 report_fatal_error("Mismatched bundle_lock/unlock directives");
54 }
55 if (--BundleLockNestingDepth == 0) {
56 BundleLockState = NotBundleLocked;
57 }
58 return;
59 }
60
61 // If any of the directives is an align_to_end directive, the whole nested
62 // group is align_to_end. So don't downgrade from align_to_end to just locked.
63 if (BundleLockState != BundleLockedAlignToEnd) {
64 BundleLockState = NewState;
65 }
66 ++BundleLockNestingDepth;
67 }
68
getVirtualSectionKind() const69 StringRef MCSection::getVirtualSectionKind() const { return "virtual"; }
70
71 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
dump() const72 LLVM_DUMP_METHOD void MCSection::dump() const {
73 raw_ostream &OS = errs();
74
75 OS << "<MCSection Name:" << getName();
76 OS << " Fragments:[\n ";
77 bool First = true;
78 for (auto &F : *this) {
79 if (First)
80 First = false;
81 else
82 OS << ",\n ";
83 F.dump();
84 }
85 OS << "]>";
86 }
87 #endif
88