diff options
Diffstat (limited to 'contrib/llvm/lib/MC/MCExpr.cpp')
| -rw-r--r-- | contrib/llvm/lib/MC/MCExpr.cpp | 284 |
1 files changed, 229 insertions, 55 deletions
diff --git a/contrib/llvm/lib/MC/MCExpr.cpp b/contrib/llvm/lib/MC/MCExpr.cpp index 343f334..54d3743 100644 --- a/contrib/llvm/lib/MC/MCExpr.cpp +++ b/contrib/llvm/lib/MC/MCExpr.cpp @@ -38,21 +38,31 @@ void MCExpr::print(raw_ostream &OS) const { 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_ARM_HI16 || - SRE.getKind() == MCSymbolRefExpr::VK_ARM_LO16) + if (SRE.getKind() == MCSymbolRefExpr::VK_PPC_HA16 || + SRE.getKind() == MCSymbolRefExpr::VK_PPC_LO16) { OS << MCSymbolRefExpr::getVariantKindName(SRE.getKind()); + UseParens = true; + } - // Parenthesize names that start with $ so that they don't look like - // absolute names. - if (Sym.getName()[0] == '$') + if (UseParens) OS << '(' << Sym << ')'; else OS << Sym; - if (SRE.getKind() != MCSymbolRefExpr::VK_None && - SRE.getKind() != MCSymbolRefExpr::VK_ARM_HI16 && - SRE.getKind() != MCSymbolRefExpr::VK_ARM_LO16) + if (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) + OS << MCSymbolRefExpr::getVariantKindName(SRE.getKind()); + else if (SRE.getKind() != MCSymbolRefExpr::VK_None && + SRE.getKind() != MCSymbolRefExpr::VK_PPC_HA16 && + SRE.getKind() != MCSymbolRefExpr::VK_PPC_LO16) OS << '@' << MCSymbolRefExpr::getVariantKindName(SRE.getKind()); return; @@ -172,12 +182,23 @@ StringRef MCSymbolRefExpr::getVariantKindName(VariantKind Kind) { 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_ARM_HI16: return ":upper16:"; - case VK_ARM_LO16: return ":lower16:"; + case VK_DTPOFF: return "DTPOFF"; case VK_TLVP: return "TLVP"; + 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_PPC_TOC: return "toc"; + case VK_PPC_HA16: return "ha16"; + case VK_PPC_LO16: return "lo16"; } } @@ -185,15 +206,33 @@ 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); } @@ -203,7 +242,28 @@ void MCTargetExpr::Anchor() {} /* *** */ -bool MCExpr::EvaluateAsAbsolute(int64_t &Res, const MCAsmLayout *Layout) const { +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. @@ -212,37 +272,159 @@ bool MCExpr::EvaluateAsAbsolute(int64_t &Res, const MCAsmLayout *Layout) const { return true; } - if (!EvaluateAsRelocatable(Value, Layout) || !Value.isAbsolute()) - return false; + // 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 true; + + 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()); + + // 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)); + + // Clear the symbol expr pointers to indicate we have folded these + // operands. + A = B = 0; } -static bool EvaluateSymbolicAdd(const MCValue &LHS,const MCSymbolRefExpr *RHS_A, +/// \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) { - // We can't add or subtract two symbols. - if ((LHS.getSymA() && RHS_A) || - (LHS.getSymB() && RHS_B)) + // 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 aggresive 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; - const MCSymbolRefExpr *A = LHS.getSymA() ? LHS.getSymA() : RHS_A; - const MCSymbolRefExpr *B = LHS.getSymB() ? LHS.getSymB() : RHS_B; - if (B) { - // If we have a negated symbol, then we must have also have a non-negated - // symbol in order to encode the expression. We can do this check later to - // permit expressions which eventually fold to a representable form -- such - // as (a + (0 - b)) -- if necessary. - if (!A) - return false; - } - Res = MCValue::get(A, B, LHS.getConstant() + RHS_Cst); + // 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 { + 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()) { @@ -258,26 +440,15 @@ bool MCExpr::EvaluateAsRelocatable(MCValue &Res, const MCSymbol &Sym = SRE->getSymbol(); // Evaluate recursively if this is a variable. - if (Sym.isVariable()) { - if (!Sym.getVariableValue()->EvaluateAsRelocatable(Res, Layout)) - return false; - - // Absolutize symbol differences between defined symbols when we have a - // layout object and the target requests it. - if (Layout && Res.getSymB() && - Layout->getAssembler().getBackend().hasAbsolutizedSet() && - Res.getSymA()->getSymbol().isDefined() && - Res.getSymB()->getSymbol().isDefined()) { - MCSymbolData &A = - Layout->getAssembler().getSymbolData(Res.getSymA()->getSymbol()); - MCSymbolData &B = - Layout->getAssembler().getSymbolData(Res.getSymB()->getSymbol()); - Res = MCValue::get(+ Layout->getSymbolAddress(&A) - - Layout->getSymbolAddress(&B) - + Res.getConstant()); - } - - return true; + 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); @@ -288,7 +459,8 @@ bool MCExpr::EvaluateAsRelocatable(MCValue &Res, const MCUnaryExpr *AUE = cast<MCUnaryExpr>(this); MCValue Value; - if (!AUE->getSubExpr()->EvaluateAsRelocatable(Value, Layout)) + if (!AUE->getSubExpr()->EvaluateAsRelocatableImpl(Value, Asm, Layout, + Addrs, InSet)) return false; switch (AUE->getOpcode()) { @@ -321,8 +493,10 @@ bool MCExpr::EvaluateAsRelocatable(MCValue &Res, const MCBinaryExpr *ABE = cast<MCBinaryExpr>(this); MCValue LHSValue, RHSValue; - if (!ABE->getLHS()->EvaluateAsRelocatable(LHSValue, Layout) || - !ABE->getRHS()->EvaluateAsRelocatable(RHSValue, Layout)) + 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 @@ -333,13 +507,13 @@ bool MCExpr::EvaluateAsRelocatable(MCValue &Res, return false; case MCBinaryExpr::Sub: // Negate RHS and add. - return EvaluateSymbolicAdd(LHSValue, + return EvaluateSymbolicAdd(Asm, Layout, Addrs, InSet, LHSValue, RHSValue.getSymB(), RHSValue.getSymA(), -RHSValue.getConstant(), Res); case MCBinaryExpr::Add: - return EvaluateSymbolicAdd(LHSValue, + return EvaluateSymbolicAdd(Asm, Layout, Addrs, InSet, LHSValue, RHSValue.getSymA(), RHSValue.getSymB(), RHSValue.getConstant(), Res); |
