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/SmallVector.h" 11 #include "llvm/Config/llvm-config.h" 12 #include "llvm/MC/MCContext.h" 13 #include "llvm/MC/MCFragment.h" 14 #include "llvm/MC/MCSymbol.h" 15 #include "llvm/Support/Compiler.h" 16 #include "llvm/Support/ErrorHandling.h" 17 #include "llvm/Support/raw_ostream.h" 18 #include <utility> 19 20 using namespace llvm; 21 22 MCSection::MCSection(SectionVariant V, StringRef Name, bool IsText, 23 bool IsVirtual, MCSymbol *Begin) 24 : Begin(Begin), BundleGroupBeforeFirstInst(false), HasInstructions(false), 25 HasLayout(false), IsRegistered(false), IsText(IsText), 26 IsVirtual(IsVirtual), Name(Name), Variant(V) { 27 DummyFragment.setParent(this); 28 // The initial subsection number is 0. Create a fragment list. 29 CurFragList = &Subsections.emplace_back(0u, FragList{}).second; 30 } 31 32 MCSymbol *MCSection::getEndSymbol(MCContext &Ctx) { 33 if (!End) 34 End = Ctx.createTempSymbol("sec_end"); 35 return End; 36 } 37 38 bool MCSection::hasEnded() const { return End && End->isInSection(); } 39 40 MCSection::~MCSection() { 41 for (auto &[_, Chain] : Subsections) { 42 for (MCFragment *X = Chain.Head, *Y; X; X = Y) { 43 Y = X->Next; 44 X->destroy(); 45 } 46 } 47 } 48 49 void MCSection::setBundleLockState(BundleLockStateType NewState) { 50 if (NewState == NotBundleLocked) { 51 if (BundleLockNestingDepth == 0) { 52 report_fatal_error("Mismatched bundle_lock/unlock directives"); 53 } 54 if (--BundleLockNestingDepth == 0) { 55 BundleLockState = NotBundleLocked; 56 } 57 return; 58 } 59 60 // If any of the directives is an align_to_end directive, the whole nested 61 // group is align_to_end. So don't downgrade from align_to_end to just locked. 62 if (BundleLockState != BundleLockedAlignToEnd) { 63 BundleLockState = NewState; 64 } 65 ++BundleLockNestingDepth; 66 } 67 68 StringRef MCSection::getVirtualSectionKind() const { return "virtual"; } 69 70 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP) 71 LLVM_DUMP_METHOD void MCSection::dump() const { 72 raw_ostream &OS = errs(); 73 74 OS << "<MCSection Name:" << getName(); 75 OS << " Fragments:[\n "; 76 bool First = true; 77 for (auto &F : *this) { 78 if (First) 79 First = false; 80 else 81 OS << ",\n "; 82 F.dump(); 83 } 84 OS << "]>"; 85 } 86 #endif 87