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Diffstat (limited to 'contrib/llvm-project/llvm/lib/MC/MCFragment.cpp')
-rw-r--r-- | contrib/llvm-project/llvm/lib/MC/MCFragment.cpp | 467 |
1 files changed, 467 insertions, 0 deletions
diff --git a/contrib/llvm-project/llvm/lib/MC/MCFragment.cpp b/contrib/llvm-project/llvm/lib/MC/MCFragment.cpp new file mode 100644 index 000000000000..ae5bd65507bc --- /dev/null +++ b/contrib/llvm-project/llvm/lib/MC/MCFragment.cpp @@ -0,0 +1,467 @@ +//===- lib/MC/MCFragment.cpp - Assembler Fragment Implementation ----------===// +// +// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. +// See https://llvm.org/LICENSE.txt for license information. +// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception +// +//===----------------------------------------------------------------------===// + +#include "llvm/MC/MCFragment.h" +#include "llvm/ADT/SmallVector.h" +#include "llvm/ADT/StringExtras.h" +#include "llvm/ADT/Twine.h" +#include "llvm/Config/llvm-config.h" +#include "llvm/MC/MCAsmLayout.h" +#include "llvm/MC/MCAssembler.h" +#include "llvm/MC/MCContext.h" +#include "llvm/MC/MCExpr.h" +#include "llvm/MC/MCFixup.h" +#include "llvm/MC/MCSection.h" +#include "llvm/MC/MCSymbol.h" +#include "llvm/MC/MCValue.h" +#include "llvm/Support/Casting.h" +#include "llvm/Support/Compiler.h" +#include "llvm/Support/ErrorHandling.h" +#include "llvm/Support/raw_ostream.h" +#include <cassert> +#include <cstdint> +#include <utility> + +using namespace llvm; + +MCAsmLayout::MCAsmLayout(MCAssembler &Asm) : Assembler(Asm) { + // Compute the section layout order. Virtual sections must go last. + for (MCSection &Sec : Asm) + if (!Sec.isVirtualSection()) + SectionOrder.push_back(&Sec); + for (MCSection &Sec : Asm) + if (Sec.isVirtualSection()) + SectionOrder.push_back(&Sec); +} + +bool MCAsmLayout::isFragmentValid(const MCFragment *F) const { + const MCSection *Sec = F->getParent(); + const MCFragment *LastValid = LastValidFragment.lookup(Sec); + if (!LastValid) + return false; + assert(LastValid->getParent() == Sec); + return F->getLayoutOrder() <= LastValid->getLayoutOrder(); +} + +void MCAsmLayout::invalidateFragmentsFrom(MCFragment *F) { + // If this fragment wasn't already valid, we don't need to do anything. + if (!isFragmentValid(F)) + return; + + // Otherwise, reset the last valid fragment to the previous fragment + // (if this is the first fragment, it will be NULL). + LastValidFragment[F->getParent()] = F->getPrevNode(); +} + +void MCAsmLayout::ensureValid(const MCFragment *F) const { + MCSection *Sec = F->getParent(); + MCSection::iterator I; + if (MCFragment *Cur = LastValidFragment[Sec]) + I = ++MCSection::iterator(Cur); + else + I = Sec->begin(); + + // Advance the layout position until the fragment is valid. + while (!isFragmentValid(F)) { + assert(I != Sec->end() && "Layout bookkeeping error"); + const_cast<MCAsmLayout *>(this)->layoutFragment(&*I); + ++I; + } +} + +uint64_t MCAsmLayout::getFragmentOffset(const MCFragment *F) const { + ensureValid(F); + assert(F->Offset != ~UINT64_C(0) && "Address not set!"); + return F->Offset; +} + +// Simple getSymbolOffset helper for the non-variable case. +static bool getLabelOffset(const MCAsmLayout &Layout, const MCSymbol &S, + bool ReportError, uint64_t &Val) { + if (!S.getFragment()) { + if (ReportError) + report_fatal_error("unable to evaluate offset to undefined symbol '" + + S.getName() + "'"); + return false; + } + Val = Layout.getFragmentOffset(S.getFragment()) + S.getOffset(); + return true; +} + +static bool getSymbolOffsetImpl(const MCAsmLayout &Layout, const MCSymbol &S, + bool ReportError, uint64_t &Val) { + if (!S.isVariable()) + return getLabelOffset(Layout, S, ReportError, Val); + + // If SD is a variable, evaluate it. + MCValue Target; + if (!S.getVariableValue()->evaluateAsValue(Target, Layout)) + report_fatal_error("unable to evaluate offset for variable '" + + S.getName() + "'"); + + uint64_t Offset = Target.getConstant(); + + const MCSymbolRefExpr *A = Target.getSymA(); + if (A) { + uint64_t ValA; + if (!getLabelOffset(Layout, A->getSymbol(), ReportError, ValA)) + return false; + Offset += ValA; + } + + const MCSymbolRefExpr *B = Target.getSymB(); + if (B) { + uint64_t ValB; + if (!getLabelOffset(Layout, B->getSymbol(), ReportError, ValB)) + return false; + Offset -= ValB; + } + + Val = Offset; + return true; +} + +bool MCAsmLayout::getSymbolOffset(const MCSymbol &S, uint64_t &Val) const { + return getSymbolOffsetImpl(*this, S, false, Val); +} + +uint64_t MCAsmLayout::getSymbolOffset(const MCSymbol &S) const { + uint64_t Val; + getSymbolOffsetImpl(*this, S, true, Val); + return Val; +} + +const MCSymbol *MCAsmLayout::getBaseSymbol(const MCSymbol &Symbol) const { + if (!Symbol.isVariable()) + return &Symbol; + + const MCExpr *Expr = Symbol.getVariableValue(); + MCValue Value; + if (!Expr->evaluateAsValue(Value, *this)) { + Assembler.getContext().reportError( + Expr->getLoc(), "expression could not be evaluated"); + return nullptr; + } + + const MCSymbolRefExpr *RefB = Value.getSymB(); + if (RefB) { + Assembler.getContext().reportError( + Expr->getLoc(), Twine("symbol '") + RefB->getSymbol().getName() + + "' could not be evaluated in a subtraction expression"); + return nullptr; + } + + const MCSymbolRefExpr *A = Value.getSymA(); + if (!A) + return nullptr; + + const MCSymbol &ASym = A->getSymbol(); + const MCAssembler &Asm = getAssembler(); + if (ASym.isCommon()) { + Asm.getContext().reportError(Expr->getLoc(), + "Common symbol '" + ASym.getName() + + "' cannot be used in assignment expr"); + return nullptr; + } + + return &ASym; +} + +uint64_t MCAsmLayout::getSectionAddressSize(const MCSection *Sec) const { + // The size is the last fragment's end offset. + const MCFragment &F = Sec->getFragmentList().back(); + return getFragmentOffset(&F) + getAssembler().computeFragmentSize(*this, F); +} + +uint64_t MCAsmLayout::getSectionFileSize(const MCSection *Sec) const { + // Virtual sections have no file size. + if (Sec->isVirtualSection()) + return 0; + + // Otherwise, the file size is the same as the address space size. + return getSectionAddressSize(Sec); +} + +uint64_t llvm::computeBundlePadding(const MCAssembler &Assembler, + const MCEncodedFragment *F, + uint64_t FOffset, uint64_t FSize) { + uint64_t BundleSize = Assembler.getBundleAlignSize(); + assert(BundleSize > 0 && + "computeBundlePadding should only be called if bundling is enabled"); + uint64_t BundleMask = BundleSize - 1; + uint64_t OffsetInBundle = FOffset & BundleMask; + uint64_t EndOfFragment = OffsetInBundle + FSize; + + // There are two kinds of bundling restrictions: + // + // 1) For alignToBundleEnd(), add padding to ensure that the fragment will + // *end* on a bundle boundary. + // 2) Otherwise, check if the fragment would cross a bundle boundary. If it + // would, add padding until the end of the bundle so that the fragment + // will start in a new one. + if (F->alignToBundleEnd()) { + // Three possibilities here: + // + // A) The fragment just happens to end at a bundle boundary, so we're good. + // B) The fragment ends before the current bundle boundary: pad it just + // enough to reach the boundary. + // C) The fragment ends after the current bundle boundary: pad it until it + // reaches the end of the next bundle boundary. + // + // Note: this code could be made shorter with some modulo trickery, but it's + // intentionally kept in its more explicit form for simplicity. + if (EndOfFragment == BundleSize) + return 0; + else if (EndOfFragment < BundleSize) + return BundleSize - EndOfFragment; + else { // EndOfFragment > BundleSize + return 2 * BundleSize - EndOfFragment; + } + } else if (OffsetInBundle > 0 && EndOfFragment > BundleSize) + return BundleSize - OffsetInBundle; + else + return 0; +} + +/* *** */ + +void ilist_alloc_traits<MCFragment>::deleteNode(MCFragment *V) { V->destroy(); } + +MCFragment::~MCFragment() = default; + +MCFragment::MCFragment(FragmentType Kind, bool HasInstructions, + MCSection *Parent) + : Kind(Kind), HasInstructions(HasInstructions), LayoutOrder(0), + Parent(Parent), Atom(nullptr), Offset(~UINT64_C(0)) { + if (Parent && !isDummy()) + Parent->getFragmentList().push_back(this); +} + +void MCFragment::destroy() { + // First check if we are the sentinal. + if (Kind == FragmentType(~0)) { + delete this; + return; + } + + switch (Kind) { + case FT_Align: + delete cast<MCAlignFragment>(this); + return; + case FT_Data: + delete cast<MCDataFragment>(this); + return; + case FT_CompactEncodedInst: + delete cast<MCCompactEncodedInstFragment>(this); + return; + case FT_Fill: + delete cast<MCFillFragment>(this); + return; + case FT_Relaxable: + delete cast<MCRelaxableFragment>(this); + return; + case FT_Org: + delete cast<MCOrgFragment>(this); + return; + case FT_Dwarf: + delete cast<MCDwarfLineAddrFragment>(this); + return; + case FT_DwarfFrame: + delete cast<MCDwarfCallFrameFragment>(this); + return; + case FT_LEB: + delete cast<MCLEBFragment>(this); + return; + case FT_Padding: + delete cast<MCPaddingFragment>(this); + return; + case FT_SymbolId: + delete cast<MCSymbolIdFragment>(this); + return; + case FT_CVInlineLines: + delete cast<MCCVInlineLineTableFragment>(this); + return; + case FT_CVDefRange: + delete cast<MCCVDefRangeFragment>(this); + return; + case FT_Dummy: + delete cast<MCDummyFragment>(this); + return; + } +} + +// Debugging methods + +namespace llvm { + +raw_ostream &operator<<(raw_ostream &OS, const MCFixup &AF) { + OS << "<MCFixup" << " Offset:" << AF.getOffset() + << " Value:" << *AF.getValue() + << " Kind:" << AF.getKind() << ">"; + return OS; +} + +} // end namespace llvm + +#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP) +LLVM_DUMP_METHOD void MCFragment::dump() const { + raw_ostream &OS = errs(); + + OS << "<"; + switch (getKind()) { + case MCFragment::FT_Align: OS << "MCAlignFragment"; break; + case MCFragment::FT_Data: OS << "MCDataFragment"; break; + case MCFragment::FT_CompactEncodedInst: + OS << "MCCompactEncodedInstFragment"; break; + case MCFragment::FT_Fill: OS << "MCFillFragment"; break; + case MCFragment::FT_Relaxable: OS << "MCRelaxableFragment"; break; + case MCFragment::FT_Org: OS << "MCOrgFragment"; break; + case MCFragment::FT_Dwarf: OS << "MCDwarfFragment"; break; + case MCFragment::FT_DwarfFrame: OS << "MCDwarfCallFrameFragment"; break; + case MCFragment::FT_LEB: OS << "MCLEBFragment"; break; + case MCFragment::FT_Padding: OS << "MCPaddingFragment"; break; + case MCFragment::FT_SymbolId: OS << "MCSymbolIdFragment"; break; + case MCFragment::FT_CVInlineLines: OS << "MCCVInlineLineTableFragment"; break; + case MCFragment::FT_CVDefRange: OS << "MCCVDefRangeTableFragment"; break; + case MCFragment::FT_Dummy: OS << "MCDummyFragment"; break; + } + + OS << "<MCFragment " << (const void *)this << " LayoutOrder:" << LayoutOrder + << " Offset:" << Offset << " HasInstructions:" << hasInstructions(); + if (const MCEncodedFragment *EF = dyn_cast<MCEncodedFragment>(this)) + OS << " BundlePadding:" << static_cast<unsigned>(EF->getBundlePadding()); + OS << ">"; + + switch (getKind()) { + case MCFragment::FT_Align: { + const MCAlignFragment *AF = cast<MCAlignFragment>(this); + if (AF->hasEmitNops()) + OS << " (emit nops)"; + OS << "\n "; + OS << " Alignment:" << AF->getAlignment() + << " Value:" << AF->getValue() << " ValueSize:" << AF->getValueSize() + << " MaxBytesToEmit:" << AF->getMaxBytesToEmit() << ">"; + break; + } + case MCFragment::FT_Data: { + const MCDataFragment *DF = cast<MCDataFragment>(this); + OS << "\n "; + OS << " Contents:["; + const SmallVectorImpl<char> &Contents = DF->getContents(); + for (unsigned i = 0, e = Contents.size(); i != e; ++i) { + if (i) OS << ","; + OS << hexdigit((Contents[i] >> 4) & 0xF) << hexdigit(Contents[i] & 0xF); + } + OS << "] (" << Contents.size() << " bytes)"; + + if (DF->fixup_begin() != DF->fixup_end()) { + OS << ",\n "; + OS << " Fixups:["; + for (MCDataFragment::const_fixup_iterator it = DF->fixup_begin(), + ie = DF->fixup_end(); it != ie; ++it) { + if (it != DF->fixup_begin()) OS << ",\n "; + OS << *it; + } + OS << "]"; + } + break; + } + case MCFragment::FT_CompactEncodedInst: { + const MCCompactEncodedInstFragment *CEIF = + cast<MCCompactEncodedInstFragment>(this); + OS << "\n "; + OS << " Contents:["; + const SmallVectorImpl<char> &Contents = CEIF->getContents(); + for (unsigned i = 0, e = Contents.size(); i != e; ++i) { + if (i) OS << ","; + OS << hexdigit((Contents[i] >> 4) & 0xF) << hexdigit(Contents[i] & 0xF); + } + OS << "] (" << Contents.size() << " bytes)"; + break; + } + case MCFragment::FT_Fill: { + const MCFillFragment *FF = cast<MCFillFragment>(this); + OS << " Value:" << static_cast<unsigned>(FF->getValue()) + << " ValueSize:" << static_cast<unsigned>(FF->getValueSize()) + << " NumValues:" << FF->getNumValues(); + break; + } + case MCFragment::FT_Relaxable: { + const MCRelaxableFragment *F = cast<MCRelaxableFragment>(this); + OS << "\n "; + OS << " Inst:"; + F->getInst().dump_pretty(OS); + break; + } + case MCFragment::FT_Org: { + const MCOrgFragment *OF = cast<MCOrgFragment>(this); + OS << "\n "; + OS << " Offset:" << OF->getOffset() + << " Value:" << static_cast<unsigned>(OF->getValue()); + break; + } + case MCFragment::FT_Dwarf: { + const MCDwarfLineAddrFragment *OF = cast<MCDwarfLineAddrFragment>(this); + OS << "\n "; + OS << " AddrDelta:" << OF->getAddrDelta() + << " LineDelta:" << OF->getLineDelta(); + break; + } + case MCFragment::FT_DwarfFrame: { + const MCDwarfCallFrameFragment *CF = cast<MCDwarfCallFrameFragment>(this); + OS << "\n "; + OS << " AddrDelta:" << CF->getAddrDelta(); + break; + } + case MCFragment::FT_LEB: { + const MCLEBFragment *LF = cast<MCLEBFragment>(this); + OS << "\n "; + OS << " Value:" << LF->getValue() << " Signed:" << LF->isSigned(); + break; + } + case MCFragment::FT_Padding: { + const MCPaddingFragment *F = cast<MCPaddingFragment>(this); + OS << "\n "; + OS << " PaddingPoliciesMask:" << F->getPaddingPoliciesMask() + << " IsInsertionPoint:" << F->isInsertionPoint() + << " Size:" << F->getSize(); + OS << "\n "; + OS << " Inst:"; + F->getInst().dump_pretty(OS); + OS << " InstSize:" << F->getInstSize(); + OS << "\n "; + break; + } + case MCFragment::FT_SymbolId: { + const MCSymbolIdFragment *F = cast<MCSymbolIdFragment>(this); + OS << "\n "; + OS << " Sym:" << F->getSymbol(); + break; + } + case MCFragment::FT_CVInlineLines: { + const auto *F = cast<MCCVInlineLineTableFragment>(this); + OS << "\n "; + OS << " Sym:" << *F->getFnStartSym(); + break; + } + case MCFragment::FT_CVDefRange: { + const auto *F = cast<MCCVDefRangeFragment>(this); + OS << "\n "; + for (std::pair<const MCSymbol *, const MCSymbol *> RangeStartEnd : + F->getRanges()) { + OS << " RangeStart:" << RangeStartEnd.first; + OS << " RangeEnd:" << RangeStartEnd.second; + } + break; + } + case MCFragment::FT_Dummy: + break; + } + OS << ">"; +} +#endif |