46beeaa394
There are only three actual uses of the section kind in MCSection: isText(), XCOFF, and WebAssembly. Store isText() in the MCSection, and store other info in the actual section variants where required. ELF and COFF flags also encode all relevant information, so for these two section variants, remove the SectionKind parameter entirely. This allows to remove the string switch (which is unnecessary and inaccurate) from createELFSectionImpl. This was introduced in [D133456](https://reviews.llvm.org/D133456), but apparently, it was never hit for non-writable sections anyway and the resulting kind was never used.
128 lines
4.0 KiB
C++
128 lines
4.0 KiB
C++
//===- lib/MC/MCSection.cpp - Machine Code Section Representation ---------===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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#include "llvm/MC/MCSection.h"
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#include "llvm/ADT/STLExtras.h"
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#include "llvm/ADT/SmallVector.h"
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#include "llvm/Config/llvm-config.h"
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#include "llvm/MC/MCContext.h"
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#include "llvm/MC/MCFragment.h"
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#include "llvm/MC/MCSymbol.h"
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#include "llvm/Support/Compiler.h"
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#include "llvm/Support/ErrorHandling.h"
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#include "llvm/Support/raw_ostream.h"
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#include <utility>
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using namespace llvm;
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MCSection::MCSection(SectionVariant V, StringRef Name, bool IsText,
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MCSymbol *Begin)
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: Begin(Begin), BundleGroupBeforeFirstInst(false), HasInstructions(false),
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HasLayout(false), IsRegistered(false), IsText(IsText),
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DummyFragment(this), Name(Name), Variant(V) {
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// The initial subsection number is 0. Create a fragment list.
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CurFragList = &Subsections.emplace_back(0u, FragList{}).second;
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}
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MCSymbol *MCSection::getEndSymbol(MCContext &Ctx) {
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if (!End)
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End = Ctx.createTempSymbol("sec_end");
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return End;
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}
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bool MCSection::hasEnded() const { return End && End->isInSection(); }
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MCSection::~MCSection() {
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for (auto &[_, Chain] : Subsections) {
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for (MCFragment *X = Chain.Head, *Y; X; X = Y) {
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Y = X->Next;
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X->destroy();
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}
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}
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}
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void MCSection::setBundleLockState(BundleLockStateType NewState) {
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if (NewState == NotBundleLocked) {
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if (BundleLockNestingDepth == 0) {
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report_fatal_error("Mismatched bundle_lock/unlock directives");
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}
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if (--BundleLockNestingDepth == 0) {
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BundleLockState = NotBundleLocked;
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}
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return;
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}
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// If any of the directives is an align_to_end directive, the whole nested
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// group is align_to_end. So don't downgrade from align_to_end to just locked.
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if (BundleLockState != BundleLockedAlignToEnd) {
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BundleLockState = NewState;
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}
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++BundleLockNestingDepth;
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}
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void MCSection::switchSubsection(unsigned Subsection) {
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size_t I = 0, E = Subsections.size();
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while (I != E && Subsections[I].first < Subsection)
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++I;
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// If the subsection number is not in the sorted Subsections list, create a
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// new fragment list.
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if (I == E || Subsections[I].first != Subsection)
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Subsections.insert(Subsections.begin() + I, {Subsection, FragList{}});
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CurFragList = &Subsections[I].second;
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}
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StringRef MCSection::getVirtualSectionKind() const { return "virtual"; }
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void MCSection::addPendingLabel(MCSymbol *label, unsigned Subsection) {
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PendingLabels.push_back(PendingLabel(label, Subsection));
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}
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void MCSection::flushPendingLabels(MCFragment *F, unsigned Subsection) {
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// Set the fragment and fragment offset for all pending symbols in the
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// specified Subsection, and remove those symbols from the pending list.
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for (auto It = PendingLabels.begin(); It != PendingLabels.end(); ++It) {
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PendingLabel& Label = *It;
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if (Label.Subsection == Subsection) {
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Label.Sym->setFragment(F);
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assert(Label.Sym->getOffset() == 0);
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PendingLabels.erase(It--);
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}
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}
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}
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void MCSection::flushPendingLabels() {
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// Make sure all remaining pending labels point to data fragments, by
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// creating new empty data fragments for each Subsection with labels pending.
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while (!PendingLabels.empty()) {
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PendingLabel& Label = PendingLabels[0];
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switchSubsection(Label.Subsection);
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MCFragment *F = new MCDataFragment();
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addFragment(*F);
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F->setParent(this);
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flushPendingLabels(F, Label.Subsection);
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}
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}
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#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
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LLVM_DUMP_METHOD void MCSection::dump() const {
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raw_ostream &OS = errs();
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OS << "<MCSection Name:" << getName();
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OS << " Fragments:[\n ";
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bool First = true;
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for (auto &F : *this) {
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if (First)
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First = false;
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else
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OS << ",\n ";
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F.dump();
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}
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OS << "]>";
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}
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#endif
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