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Diffstat (limited to 'contrib/llvm/lib/MC/MCExpr.cpp')
| -rw-r--r-- | contrib/llvm/lib/MC/MCExpr.cpp | 658 |
1 files changed, 658 insertions, 0 deletions
diff --git a/contrib/llvm/lib/MC/MCExpr.cpp b/contrib/llvm/lib/MC/MCExpr.cpp new file mode 100644 index 0000000..cd4d144 --- /dev/null +++ b/contrib/llvm/lib/MC/MCExpr.cpp @@ -0,0 +1,658 @@ +//===- MCExpr.cpp - Assembly Level Expression Implementation --------------===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// + +#define DEBUG_TYPE "mcexpr" +#include "llvm/MC/MCExpr.h" +#include "llvm/ADT/Statistic.h" +#include "llvm/ADT/StringSwitch.h" +#include "llvm/MC/MCAsmLayout.h" +#include "llvm/MC/MCAssembler.h" +#include "llvm/MC/MCContext.h" +#include "llvm/MC/MCObjectWriter.h" +#include "llvm/MC/MCSymbol.h" +#include "llvm/MC/MCValue.h" +#include "llvm/Support/Debug.h" +#include "llvm/Support/ErrorHandling.h" +#include "llvm/Support/raw_ostream.h" +using namespace llvm; + +namespace { +namespace stats { +STATISTIC(MCExprEvaluate, "Number of MCExpr evaluations"); +} +} + +void MCExpr::print(raw_ostream &OS) const { + switch (getKind()) { + case MCExpr::Target: + return cast<MCTargetExpr>(this)->PrintImpl(OS); + case MCExpr::Constant: + OS << cast<MCConstantExpr>(*this).getValue(); + return; + + case MCExpr::SymbolRef: { + const MCSymbolRefExpr &SRE = cast<MCSymbolRefExpr>(*this); + const MCSymbol &Sym = SRE.getSymbol(); + // Parenthesize names that start with $ so that they don't look like + // absolute names. + bool UseParens = Sym.getName()[0] == '$'; + + if (SRE.getKind() == MCSymbolRefExpr::VK_PPC_DARWIN_HA16 || + SRE.getKind() == MCSymbolRefExpr::VK_PPC_DARWIN_LO16) { + OS << MCSymbolRefExpr::getVariantKindName(SRE.getKind()); + UseParens = true; + } + + if (UseParens) + OS << '(' << Sym << ')'; + else + OS << Sym; + + if (SRE.getKind() == MCSymbolRefExpr::VK_ARM_NONE || + SRE.getKind() == MCSymbolRefExpr::VK_ARM_PLT || + SRE.getKind() == MCSymbolRefExpr::VK_ARM_TLSGD || + SRE.getKind() == MCSymbolRefExpr::VK_ARM_GOT || + SRE.getKind() == MCSymbolRefExpr::VK_ARM_GOTOFF || + SRE.getKind() == MCSymbolRefExpr::VK_ARM_TPOFF || + SRE.getKind() == MCSymbolRefExpr::VK_ARM_GOTTPOFF || + SRE.getKind() == MCSymbolRefExpr::VK_ARM_TARGET1 || + SRE.getKind() == MCSymbolRefExpr::VK_ARM_TARGET2 || + SRE.getKind() == MCSymbolRefExpr::VK_ARM_PREL31) + OS << MCSymbolRefExpr::getVariantKindName(SRE.getKind()); + else if (SRE.getKind() != MCSymbolRefExpr::VK_None && + SRE.getKind() != MCSymbolRefExpr::VK_PPC_DARWIN_HA16 && + SRE.getKind() != MCSymbolRefExpr::VK_PPC_DARWIN_LO16) + OS << '@' << MCSymbolRefExpr::getVariantKindName(SRE.getKind()); + + return; + } + + case MCExpr::Unary: { + const MCUnaryExpr &UE = cast<MCUnaryExpr>(*this); + switch (UE.getOpcode()) { + case MCUnaryExpr::LNot: OS << '!'; break; + case MCUnaryExpr::Minus: OS << '-'; break; + case MCUnaryExpr::Not: OS << '~'; break; + case MCUnaryExpr::Plus: OS << '+'; break; + } + OS << *UE.getSubExpr(); + return; + } + + case MCExpr::Binary: { + const MCBinaryExpr &BE = cast<MCBinaryExpr>(*this); + + // Only print parens around the LHS if it is non-trivial. + if (isa<MCConstantExpr>(BE.getLHS()) || isa<MCSymbolRefExpr>(BE.getLHS())) { + OS << *BE.getLHS(); + } else { + OS << '(' << *BE.getLHS() << ')'; + } + + switch (BE.getOpcode()) { + case MCBinaryExpr::Add: + // Print "X-42" instead of "X+-42". + if (const MCConstantExpr *RHSC = dyn_cast<MCConstantExpr>(BE.getRHS())) { + if (RHSC->getValue() < 0) { + OS << RHSC->getValue(); + return; + } + } + + OS << '+'; + break; + case MCBinaryExpr::And: OS << '&'; break; + case MCBinaryExpr::Div: OS << '/'; break; + case MCBinaryExpr::EQ: OS << "=="; break; + case MCBinaryExpr::GT: OS << '>'; break; + case MCBinaryExpr::GTE: OS << ">="; break; + case MCBinaryExpr::LAnd: OS << "&&"; break; + case MCBinaryExpr::LOr: OS << "||"; break; + case MCBinaryExpr::LT: OS << '<'; break; + case MCBinaryExpr::LTE: OS << "<="; break; + case MCBinaryExpr::Mod: OS << '%'; break; + case MCBinaryExpr::Mul: OS << '*'; break; + case MCBinaryExpr::NE: OS << "!="; break; + case MCBinaryExpr::Or: OS << '|'; break; + case MCBinaryExpr::Shl: OS << "<<"; break; + case MCBinaryExpr::Shr: OS << ">>"; break; + case MCBinaryExpr::Sub: OS << '-'; break; + case MCBinaryExpr::Xor: OS << '^'; break; + } + + // Only print parens around the LHS if it is non-trivial. + if (isa<MCConstantExpr>(BE.getRHS()) || isa<MCSymbolRefExpr>(BE.getRHS())) { + OS << *BE.getRHS(); + } else { + OS << '(' << *BE.getRHS() << ')'; + } + return; + } + } + + llvm_unreachable("Invalid expression kind!"); +} + +#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP) +void MCExpr::dump() const { + print(dbgs()); + dbgs() << '\n'; +} +#endif + +/* *** */ + +const MCBinaryExpr *MCBinaryExpr::Create(Opcode Opc, const MCExpr *LHS, + const MCExpr *RHS, MCContext &Ctx) { + return new (Ctx) MCBinaryExpr(Opc, LHS, RHS); +} + +const MCUnaryExpr *MCUnaryExpr::Create(Opcode Opc, const MCExpr *Expr, + MCContext &Ctx) { + return new (Ctx) MCUnaryExpr(Opc, Expr); +} + +const MCConstantExpr *MCConstantExpr::Create(int64_t Value, MCContext &Ctx) { + return new (Ctx) MCConstantExpr(Value); +} + +/* *** */ + +const MCSymbolRefExpr *MCSymbolRefExpr::Create(const MCSymbol *Sym, + VariantKind Kind, + MCContext &Ctx) { + return new (Ctx) MCSymbolRefExpr(Sym, Kind); +} + +const MCSymbolRefExpr *MCSymbolRefExpr::Create(StringRef Name, VariantKind Kind, + MCContext &Ctx) { + return Create(Ctx.GetOrCreateSymbol(Name), Kind, Ctx); +} + +StringRef MCSymbolRefExpr::getVariantKindName(VariantKind Kind) { + switch (Kind) { + case VK_Invalid: return "<<invalid>>"; + case VK_None: return "<<none>>"; + + case VK_GOT: return "GOT"; + case VK_GOTOFF: return "GOTOFF"; + case VK_GOTPCREL: return "GOTPCREL"; + case VK_GOTTPOFF: return "GOTTPOFF"; + case VK_INDNTPOFF: return "INDNTPOFF"; + case VK_NTPOFF: return "NTPOFF"; + case VK_GOTNTPOFF: return "GOTNTPOFF"; + case VK_PLT: return "PLT"; + case VK_TLSGD: return "TLSGD"; + case VK_TLSLD: return "TLSLD"; + case VK_TLSLDM: return "TLSLDM"; + case VK_TPOFF: return "TPOFF"; + case VK_DTPOFF: return "DTPOFF"; + case VK_TLVP: return "TLVP"; + case VK_SECREL: return "SECREL32"; + case VK_ARM_NONE: return "(NONE)"; + case VK_ARM_PLT: return "(PLT)"; + case VK_ARM_GOT: return "(GOT)"; + case VK_ARM_GOTOFF: return "(GOTOFF)"; + case VK_ARM_TPOFF: return "(tpoff)"; + case VK_ARM_GOTTPOFF: return "(gottpoff)"; + case VK_ARM_TLSGD: return "(tlsgd)"; + case VK_ARM_TARGET1: return "(target1)"; + case VK_ARM_TARGET2: return "(target2)"; + case VK_ARM_PREL31: return "(prel31)"; + case VK_PPC_TOC: return "tocbase"; + case VK_PPC_TOC_ENTRY: return "toc"; + case VK_PPC_DARWIN_HA16: return "ha16"; + case VK_PPC_DARWIN_LO16: return "lo16"; + case VK_PPC_GAS_HA16: return "ha"; + case VK_PPC_GAS_LO16: return "l"; + case VK_PPC_TPREL16_HA: return "tprel@ha"; + case VK_PPC_TPREL16_LO: return "tprel@l"; + case VK_PPC_DTPREL16_HA: return "dtprel@ha"; + case VK_PPC_DTPREL16_LO: return "dtprel@l"; + case VK_PPC_TOC16_HA: return "toc@ha"; + case VK_PPC_TOC16_LO: return "toc@l"; + case VK_PPC_GOT_TPREL16_HA: return "got@tprel@ha"; + case VK_PPC_GOT_TPREL16_LO: return "got@tprel@l"; + case VK_PPC_TLS: return "tls"; + case VK_PPC_GOT_TLSGD16_HA: return "got@tlsgd@ha"; + case VK_PPC_GOT_TLSGD16_LO: return "got@tlsgd@l"; + case VK_PPC_GOT_TLSLD16_HA: return "got@tlsld@ha"; + case VK_PPC_GOT_TLSLD16_LO: return "got@tlsld@l"; + case VK_PPC_TLSGD: return "tlsgd"; + case VK_PPC_TLSLD: return "tlsld"; + case VK_Mips_GPREL: return "GPREL"; + case VK_Mips_GOT_CALL: return "GOT_CALL"; + case VK_Mips_GOT16: return "GOT16"; + case VK_Mips_GOT: return "GOT"; + case VK_Mips_ABS_HI: return "ABS_HI"; + case VK_Mips_ABS_LO: return "ABS_LO"; + case VK_Mips_TLSGD: return "TLSGD"; + case VK_Mips_TLSLDM: return "TLSLDM"; + case VK_Mips_DTPREL_HI: return "DTPREL_HI"; + case VK_Mips_DTPREL_LO: return "DTPREL_LO"; + case VK_Mips_GOTTPREL: return "GOTTPREL"; + case VK_Mips_TPREL_HI: return "TPREL_HI"; + case VK_Mips_TPREL_LO: return "TPREL_LO"; + case VK_Mips_GPOFF_HI: return "GPOFF_HI"; + case VK_Mips_GPOFF_LO: return "GPOFF_LO"; + case VK_Mips_GOT_DISP: return "GOT_DISP"; + case VK_Mips_GOT_PAGE: return "GOT_PAGE"; + case VK_Mips_GOT_OFST: return "GOT_OFST"; + case VK_Mips_HIGHER: return "HIGHER"; + case VK_Mips_HIGHEST: return "HIGHEST"; + case VK_Mips_GOT_HI16: return "GOT_HI16"; + case VK_Mips_GOT_LO16: return "GOT_LO16"; + case VK_Mips_CALL_HI16: return "CALL_HI16"; + case VK_Mips_CALL_LO16: return "CALL_LO16"; + } + llvm_unreachable("Invalid variant kind"); +} + +MCSymbolRefExpr::VariantKind +MCSymbolRefExpr::getVariantKindForName(StringRef Name) { + return StringSwitch<VariantKind>(Name) + .Case("GOT", VK_GOT) + .Case("got", VK_GOT) + .Case("GOTOFF", VK_GOTOFF) + .Case("gotoff", VK_GOTOFF) + .Case("GOTPCREL", VK_GOTPCREL) + .Case("gotpcrel", VK_GOTPCREL) + .Case("GOTTPOFF", VK_GOTTPOFF) + .Case("gottpoff", VK_GOTTPOFF) + .Case("INDNTPOFF", VK_INDNTPOFF) + .Case("indntpoff", VK_INDNTPOFF) + .Case("NTPOFF", VK_NTPOFF) + .Case("ntpoff", VK_NTPOFF) + .Case("GOTNTPOFF", VK_GOTNTPOFF) + .Case("gotntpoff", VK_GOTNTPOFF) + .Case("PLT", VK_PLT) + .Case("plt", VK_PLT) + .Case("TLSGD", VK_TLSGD) + .Case("tlsgd", VK_TLSGD) + .Case("TLSLD", VK_TLSLD) + .Case("tlsld", VK_TLSLD) + .Case("TLSLDM", VK_TLSLDM) + .Case("tlsldm", VK_TLSLDM) + .Case("TPOFF", VK_TPOFF) + .Case("tpoff", VK_TPOFF) + .Case("DTPOFF", VK_DTPOFF) + .Case("dtpoff", VK_DTPOFF) + .Case("TLVP", VK_TLVP) + .Case("tlvp", VK_TLVP) + .Default(VK_Invalid); +} + +/* *** */ + +void MCTargetExpr::anchor() {} + +/* *** */ + +bool MCExpr::EvaluateAsAbsolute(int64_t &Res) const { + return EvaluateAsAbsolute(Res, 0, 0, 0); +} + +bool MCExpr::EvaluateAsAbsolute(int64_t &Res, + const MCAsmLayout &Layout) const { + return EvaluateAsAbsolute(Res, &Layout.getAssembler(), &Layout, 0); +} + +bool MCExpr::EvaluateAsAbsolute(int64_t &Res, + const MCAsmLayout &Layout, + const SectionAddrMap &Addrs) const { + return EvaluateAsAbsolute(Res, &Layout.getAssembler(), &Layout, &Addrs); +} + +bool MCExpr::EvaluateAsAbsolute(int64_t &Res, const MCAssembler &Asm) const { + return EvaluateAsAbsolute(Res, &Asm, 0, 0); +} + +bool MCExpr::EvaluateAsAbsolute(int64_t &Res, const MCAssembler *Asm, + const MCAsmLayout *Layout, + const SectionAddrMap *Addrs) const { + MCValue Value; + + // Fast path constants. + if (const MCConstantExpr *CE = dyn_cast<MCConstantExpr>(this)) { + Res = CE->getValue(); + return true; + } + + // FIXME: The use if InSet = Addrs is a hack. Setting InSet causes us + // absolutize differences across sections and that is what the MachO writer + // uses Addrs for. + bool IsRelocatable = + EvaluateAsRelocatableImpl(Value, Asm, Layout, Addrs, /*InSet*/ Addrs); + + // Record the current value. + Res = Value.getConstant(); + + return IsRelocatable && Value.isAbsolute(); +} + +/// \brief Helper method for \see EvaluateSymbolAdd(). +static void AttemptToFoldSymbolOffsetDifference(const MCAssembler *Asm, + const MCAsmLayout *Layout, + const SectionAddrMap *Addrs, + bool InSet, + const MCSymbolRefExpr *&A, + const MCSymbolRefExpr *&B, + int64_t &Addend) { + if (!A || !B) + return; + + const MCSymbol &SA = A->getSymbol(); + const MCSymbol &SB = B->getSymbol(); + + if (SA.isUndefined() || SB.isUndefined()) + return; + + if (!Asm->getWriter().IsSymbolRefDifferenceFullyResolved(*Asm, A, B, InSet)) + return; + + MCSymbolData &AD = Asm->getSymbolData(SA); + MCSymbolData &BD = Asm->getSymbolData(SB); + + if (AD.getFragment() == BD.getFragment()) { + Addend += (AD.getOffset() - BD.getOffset()); + + // Pointers to Thumb symbols need to have their low-bit set to allow + // for interworking. + if (Asm->isThumbFunc(&SA)) + Addend |= 1; + + // Clear the symbol expr pointers to indicate we have folded these + // operands. + A = B = 0; + return; + } + + if (!Layout) + return; + + const MCSectionData &SecA = *AD.getFragment()->getParent(); + const MCSectionData &SecB = *BD.getFragment()->getParent(); + + if ((&SecA != &SecB) && !Addrs) + return; + + // Eagerly evaluate. + Addend += (Layout->getSymbolOffset(&Asm->getSymbolData(A->getSymbol())) - + Layout->getSymbolOffset(&Asm->getSymbolData(B->getSymbol()))); + if (Addrs && (&SecA != &SecB)) + Addend += (Addrs->lookup(&SecA) - Addrs->lookup(&SecB)); + + // Pointers to Thumb symbols need to have their low-bit set to allow + // for interworking. + if (Asm->isThumbFunc(&SA)) + Addend |= 1; + + // Clear the symbol expr pointers to indicate we have folded these + // operands. + A = B = 0; +} + +/// \brief Evaluate the result of an add between (conceptually) two MCValues. +/// +/// This routine conceptually attempts to construct an MCValue: +/// Result = (Result_A - Result_B + Result_Cst) +/// from two MCValue's LHS and RHS where +/// Result = LHS + RHS +/// and +/// Result = (LHS_A - LHS_B + LHS_Cst) + (RHS_A - RHS_B + RHS_Cst). +/// +/// This routine attempts to aggresively fold the operands such that the result +/// is representable in an MCValue, but may not always succeed. +/// +/// \returns True on success, false if the result is not representable in an +/// MCValue. + +/// NOTE: It is really important to have both the Asm and Layout arguments. +/// They might look redundant, but this function can be used before layout +/// is done (see the object streamer for example) and having the Asm argument +/// lets us avoid relaxations early. +static bool EvaluateSymbolicAdd(const MCAssembler *Asm, + const MCAsmLayout *Layout, + const SectionAddrMap *Addrs, + bool InSet, + const MCValue &LHS,const MCSymbolRefExpr *RHS_A, + const MCSymbolRefExpr *RHS_B, int64_t RHS_Cst, + MCValue &Res) { + // FIXME: This routine (and other evaluation parts) are *incredibly* sloppy + // about dealing with modifiers. This will ultimately bite us, one day. + const MCSymbolRefExpr *LHS_A = LHS.getSymA(); + const MCSymbolRefExpr *LHS_B = LHS.getSymB(); + int64_t LHS_Cst = LHS.getConstant(); + + // Fold the result constant immediately. + int64_t Result_Cst = LHS_Cst + RHS_Cst; + + assert((!Layout || Asm) && + "Must have an assembler object if layout is given!"); + + // If we have a layout, we can fold resolved differences. + if (Asm) { + // First, fold out any differences which are fully resolved. By + // reassociating terms in + // Result = (LHS_A - LHS_B + LHS_Cst) + (RHS_A - RHS_B + RHS_Cst). + // we have the four possible differences: + // (LHS_A - LHS_B), + // (LHS_A - RHS_B), + // (RHS_A - LHS_B), + // (RHS_A - RHS_B). + // Since we are attempting to be as aggressive as possible about folding, we + // attempt to evaluate each possible alternative. + AttemptToFoldSymbolOffsetDifference(Asm, Layout, Addrs, InSet, LHS_A, LHS_B, + Result_Cst); + AttemptToFoldSymbolOffsetDifference(Asm, Layout, Addrs, InSet, LHS_A, RHS_B, + Result_Cst); + AttemptToFoldSymbolOffsetDifference(Asm, Layout, Addrs, InSet, RHS_A, LHS_B, + Result_Cst); + AttemptToFoldSymbolOffsetDifference(Asm, Layout, Addrs, InSet, RHS_A, RHS_B, + Result_Cst); + } + + // We can't represent the addition or subtraction of two symbols. + if ((LHS_A && RHS_A) || (LHS_B && RHS_B)) + return false; + + // At this point, we have at most one additive symbol and one subtractive + // symbol -- find them. + const MCSymbolRefExpr *A = LHS_A ? LHS_A : RHS_A; + const MCSymbolRefExpr *B = LHS_B ? LHS_B : RHS_B; + + // If we have a negated symbol, then we must have also have a non-negated + // symbol in order to encode the expression. + if (B && !A) + return false; + + Res = MCValue::get(A, B, Result_Cst); + return true; +} + +bool MCExpr::EvaluateAsRelocatable(MCValue &Res, + const MCAsmLayout &Layout) const { + return EvaluateAsRelocatableImpl(Res, &Layout.getAssembler(), &Layout, + 0, false); +} + +bool MCExpr::EvaluateAsRelocatableImpl(MCValue &Res, + const MCAssembler *Asm, + const MCAsmLayout *Layout, + const SectionAddrMap *Addrs, + bool InSet) const { + ++stats::MCExprEvaluate; + + switch (getKind()) { + case Target: + return cast<MCTargetExpr>(this)->EvaluateAsRelocatableImpl(Res, Layout); + + case Constant: + Res = MCValue::get(cast<MCConstantExpr>(this)->getValue()); + return true; + + case SymbolRef: { + const MCSymbolRefExpr *SRE = cast<MCSymbolRefExpr>(this); + const MCSymbol &Sym = SRE->getSymbol(); + + // Evaluate recursively if this is a variable. + if (Sym.isVariable() && SRE->getKind() == MCSymbolRefExpr::VK_None) { + bool Ret = Sym.getVariableValue()->EvaluateAsRelocatableImpl(Res, Asm, + Layout, + Addrs, + true); + // If we failed to simplify this to a constant, let the target + // handle it. + if (Ret && !Res.getSymA() && !Res.getSymB()) + return true; + } + + Res = MCValue::get(SRE, 0, 0); + return true; + } + + case Unary: { + const MCUnaryExpr *AUE = cast<MCUnaryExpr>(this); + MCValue Value; + + if (!AUE->getSubExpr()->EvaluateAsRelocatableImpl(Value, Asm, Layout, + Addrs, InSet)) + return false; + + switch (AUE->getOpcode()) { + case MCUnaryExpr::LNot: + if (!Value.isAbsolute()) + return false; + Res = MCValue::get(!Value.getConstant()); + break; + case MCUnaryExpr::Minus: + /// -(a - b + const) ==> (b - a - const) + if (Value.getSymA() && !Value.getSymB()) + return false; + Res = MCValue::get(Value.getSymB(), Value.getSymA(), + -Value.getConstant()); + break; + case MCUnaryExpr::Not: + if (!Value.isAbsolute()) + return false; + Res = MCValue::get(~Value.getConstant()); + break; + case MCUnaryExpr::Plus: + Res = Value; + break; + } + + return true; + } + + case Binary: { + const MCBinaryExpr *ABE = cast<MCBinaryExpr>(this); + MCValue LHSValue, RHSValue; + + if (!ABE->getLHS()->EvaluateAsRelocatableImpl(LHSValue, Asm, Layout, + Addrs, InSet) || + !ABE->getRHS()->EvaluateAsRelocatableImpl(RHSValue, Asm, Layout, + Addrs, InSet)) + return false; + + // We only support a few operations on non-constant expressions, handle + // those first. + if (!LHSValue.isAbsolute() || !RHSValue.isAbsolute()) { + switch (ABE->getOpcode()) { + default: + return false; + case MCBinaryExpr::Sub: + // Negate RHS and add. + return EvaluateSymbolicAdd(Asm, Layout, Addrs, InSet, LHSValue, + RHSValue.getSymB(), RHSValue.getSymA(), + -RHSValue.getConstant(), + Res); + + case MCBinaryExpr::Add: + return EvaluateSymbolicAdd(Asm, Layout, Addrs, InSet, LHSValue, + RHSValue.getSymA(), RHSValue.getSymB(), + RHSValue.getConstant(), + Res); + } + } + + // FIXME: We need target hooks for the evaluation. It may be limited in + // width, and gas defines the result of comparisons and right shifts + // differently from Apple as. + int64_t LHS = LHSValue.getConstant(), RHS = RHSValue.getConstant(); + int64_t Result = 0; + switch (ABE->getOpcode()) { + case MCBinaryExpr::Add: Result = LHS + RHS; break; + case MCBinaryExpr::And: Result = LHS & RHS; break; + case MCBinaryExpr::Div: Result = LHS / RHS; break; + case MCBinaryExpr::EQ: Result = LHS == RHS; break; + case MCBinaryExpr::GT: Result = LHS > RHS; break; + case MCBinaryExpr::GTE: Result = LHS >= RHS; break; + case MCBinaryExpr::LAnd: Result = LHS && RHS; break; + case MCBinaryExpr::LOr: Result = LHS || RHS; break; + case MCBinaryExpr::LT: Result = LHS < RHS; break; + case MCBinaryExpr::LTE: Result = LHS <= RHS; break; + case MCBinaryExpr::Mod: Result = LHS % RHS; break; + case MCBinaryExpr::Mul: Result = LHS * RHS; break; + case MCBinaryExpr::NE: Result = LHS != RHS; break; + case MCBinaryExpr::Or: Result = LHS | RHS; break; + case MCBinaryExpr::Shl: Result = LHS << RHS; break; + case MCBinaryExpr::Shr: Result = LHS >> RHS; break; + case MCBinaryExpr::Sub: Result = LHS - RHS; break; + case MCBinaryExpr::Xor: Result = LHS ^ RHS; break; + } + + Res = MCValue::get(Result); + return true; + } + } + + llvm_unreachable("Invalid assembly expression kind!"); +} + +const MCSection *MCExpr::FindAssociatedSection() const { + switch (getKind()) { + case Target: + // We never look through target specific expressions. + return cast<MCTargetExpr>(this)->FindAssociatedSection(); + + case Constant: + return MCSymbol::AbsolutePseudoSection; + + case SymbolRef: { + const MCSymbolRefExpr *SRE = cast<MCSymbolRefExpr>(this); + const MCSymbol &Sym = SRE->getSymbol(); + + if (Sym.isDefined()) + return &Sym.getSection(); + + return 0; + } + + case Unary: + return cast<MCUnaryExpr>(this)->getSubExpr()->FindAssociatedSection(); + + case Binary: { + const MCBinaryExpr *BE = cast<MCBinaryExpr>(this); + const MCSection *LHS_S = BE->getLHS()->FindAssociatedSection(); + const MCSection *RHS_S = BE->getRHS()->FindAssociatedSection(); + + // If either section is absolute, return the other. + if (LHS_S == MCSymbol::AbsolutePseudoSection) + return RHS_S; + if (RHS_S == MCSymbol::AbsolutePseudoSection) + return LHS_S; + + // Otherwise, return the first non-null section. + return LHS_S ? LHS_S : RHS_S; + } + } + + llvm_unreachable("Invalid assembly expression kind!"); +} |
