| //===- 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. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "llvm/MC/MCExpr.h" |
| #include "llvm/ADT/Statistic.h" |
| #include "llvm/ADT/StringSwitch.h" |
| #include "llvm/Config/llvm-config.h" |
| #include "llvm/MC/MCAsmBackend.h" |
| #include "llvm/MC/MCAsmInfo.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/Casting.h" |
| #include "llvm/Support/Compiler.h" |
| #include "llvm/Support/Debug.h" |
| #include "llvm/Support/ErrorHandling.h" |
| #include "llvm/Support/raw_ostream.h" |
| #include <cassert> |
| #include <cstdint> |
| |
| using namespace llvm; |
| |
| #define DEBUG_TYPE "mcexpr" |
| |
| namespace { |
| namespace stats { |
| |
| STATISTIC(MCExprEvaluate, "Number of MCExpr evaluations"); |
| |
| } // end namespace stats |
| } // end anonymous namespace |
| |
| void MCExpr::print(raw_ostream &OS, const MCAsmInfo *MAI, bool InParens) const { |
| switch (getKind()) { |
| case MCExpr::Target: |
| return cast<MCTargetExpr>(this)->printImpl(OS, MAI); |
| 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 = |
| !InParens && !Sym.getName().empty() && Sym.getName()[0] == '$'; |
| if (UseParens) { |
| OS << '('; |
| Sym.print(OS, MAI); |
| OS << ')'; |
| } else |
| Sym.print(OS, MAI); |
| |
| if (SRE.getKind() != MCSymbolRefExpr::VK_None) |
| SRE.printVariantKind(OS); |
| |
| 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; |
| } |
| bool Binary = UE.getSubExpr()->getKind() == MCExpr::Binary; |
| if (Binary) OS << "("; |
| UE.getSubExpr()->print(OS, MAI); |
| if (Binary) OS << ")"; |
| 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())) { |
| BE.getLHS()->print(OS, MAI); |
| } else { |
| OS << '('; |
| BE.getLHS()->print(OS, MAI); |
| OS << ')'; |
| } |
| |
| 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::AShr: 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::LShr: 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::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())) { |
| BE.getRHS()->print(OS, MAI); |
| } else { |
| OS << '('; |
| BE.getRHS()->print(OS, MAI); |
| OS << ')'; |
| } |
| return; |
| } |
| } |
| |
| llvm_unreachable("Invalid expression kind!"); |
| } |
| |
| #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP) |
| LLVM_DUMP_METHOD void MCExpr::dump() const { |
| dbgs() << *this; |
| dbgs() << '\n'; |
| } |
| #endif |
| |
| /* *** */ |
| |
| const MCBinaryExpr *MCBinaryExpr::create(Opcode Opc, const MCExpr *LHS, |
| const MCExpr *RHS, MCContext &Ctx, |
| SMLoc Loc) { |
| return new (Ctx) MCBinaryExpr(Opc, LHS, RHS, Loc); |
| } |
| |
| const MCUnaryExpr *MCUnaryExpr::create(Opcode Opc, const MCExpr *Expr, |
| MCContext &Ctx, SMLoc Loc) { |
| return new (Ctx) MCUnaryExpr(Opc, Expr, Loc); |
| } |
| |
| const MCConstantExpr *MCConstantExpr::create(int64_t Value, MCContext &Ctx) { |
| return new (Ctx) MCConstantExpr(Value); |
| } |
| |
| /* *** */ |
| |
| MCSymbolRefExpr::MCSymbolRefExpr(const MCSymbol *Symbol, VariantKind Kind, |
| const MCAsmInfo *MAI, SMLoc Loc) |
| : MCExpr(MCExpr::SymbolRef, Loc), Kind(Kind), |
| UseParensForSymbolVariant(MAI->useParensForSymbolVariant()), |
| HasSubsectionsViaSymbols(MAI->hasSubsectionsViaSymbols()), |
| Symbol(Symbol) { |
| assert(Symbol); |
| } |
| |
| const MCSymbolRefExpr *MCSymbolRefExpr::create(const MCSymbol *Sym, |
| VariantKind Kind, |
| MCContext &Ctx, SMLoc Loc) { |
| return new (Ctx) MCSymbolRefExpr(Sym, Kind, Ctx.getAsmInfo(), Loc); |
| } |
| |
| 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_DTPOFF: return "DTPOFF"; |
| case VK_DTPREL: return "DTPREL"; |
| case VK_GOT: return "GOT"; |
| case VK_GOTOFF: return "GOTOFF"; |
| case VK_GOTREL: return "GOTREL"; |
| 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_TPREL: return "TPREL"; |
| case VK_TLSCALL: return "tlscall"; |
| case VK_TLSDESC: return "tlsdesc"; |
| case VK_TLVP: return "TLVP"; |
| case VK_TLVPPAGE: return "TLVPPAGE"; |
| case VK_TLVPPAGEOFF: return "TLVPPAGEOFF"; |
| case VK_PAGE: return "PAGE"; |
| case VK_PAGEOFF: return "PAGEOFF"; |
| case VK_GOTPAGE: return "GOTPAGE"; |
| case VK_GOTPAGEOFF: return "GOTPAGEOFF"; |
| case VK_SECREL: return "SECREL32"; |
| case VK_SIZE: return "SIZE"; |
| case VK_WEAKREF: return "WEAKREF"; |
| case VK_X86_ABS8: return "ABS8"; |
| case VK_ARM_NONE: return "none"; |
| case VK_ARM_GOT_PREL: return "GOT_PREL"; |
| case VK_ARM_TARGET1: return "target1"; |
| case VK_ARM_TARGET2: return "target2"; |
| case VK_ARM_PREL31: return "prel31"; |
| case VK_ARM_SBREL: return "sbrel"; |
| case VK_ARM_TLSLDO: return "tlsldo"; |
| case VK_ARM_TLSDESCSEQ: return "tlsdescseq"; |
| case VK_AVR_NONE: return "none"; |
| case VK_AVR_LO8: return "lo8"; |
| case VK_AVR_HI8: return "hi8"; |
| case VK_AVR_HLO8: return "hlo8"; |
| case VK_AVR_DIFF8: return "diff8"; |
| case VK_AVR_DIFF16: return "diff16"; |
| case VK_AVR_DIFF32: return "diff32"; |
| case VK_PPC_LO: return "l"; |
| case VK_PPC_HI: return "h"; |
| case VK_PPC_HA: return "ha"; |
| case VK_PPC_HIGH: return "high"; |
| case VK_PPC_HIGHA: return "higha"; |
| case VK_PPC_HIGHER: return "higher"; |
| case VK_PPC_HIGHERA: return "highera"; |
| case VK_PPC_HIGHEST: return "highest"; |
| case VK_PPC_HIGHESTA: return "highesta"; |
| case VK_PPC_GOT_LO: return "got@l"; |
| case VK_PPC_GOT_HI: return "got@h"; |
| case VK_PPC_GOT_HA: return "got@ha"; |
| case VK_PPC_TOCBASE: return "tocbase"; |
| case VK_PPC_TOC: return "toc"; |
| case VK_PPC_TOC_LO: return "toc@l"; |
| case VK_PPC_TOC_HI: return "toc@h"; |
| case VK_PPC_TOC_HA: return "toc@ha"; |
| case VK_PPC_DTPMOD: return "dtpmod"; |
| case VK_PPC_TPREL_LO: return "tprel@l"; |
| case VK_PPC_TPREL_HI: return "tprel@h"; |
| case VK_PPC_TPREL_HA: return "tprel@ha"; |
| case VK_PPC_TPREL_HIGH: return "tprel@high"; |
| case VK_PPC_TPREL_HIGHA: return "tprel@higha"; |
| case VK_PPC_TPREL_HIGHER: return "tprel@higher"; |
| case VK_PPC_TPREL_HIGHERA: return "tprel@highera"; |
| case VK_PPC_TPREL_HIGHEST: return "tprel@highest"; |
| case VK_PPC_TPREL_HIGHESTA: return "tprel@highesta"; |
| case VK_PPC_DTPREL_LO: return "dtprel@l"; |
| case VK_PPC_DTPREL_HI: return "dtprel@h"; |
| case VK_PPC_DTPREL_HA: return "dtprel@ha"; |
| case VK_PPC_DTPREL_HIGH: return "dtprel@high"; |
| case VK_PPC_DTPREL_HIGHA: return "dtprel@higha"; |
| case VK_PPC_DTPREL_HIGHER: return "dtprel@higher"; |
| case VK_PPC_DTPREL_HIGHERA: return "dtprel@highera"; |
| case VK_PPC_DTPREL_HIGHEST: return "dtprel@highest"; |
| case VK_PPC_DTPREL_HIGHESTA: return "dtprel@highesta"; |
| case VK_PPC_GOT_TPREL: return "got@tprel"; |
| case VK_PPC_GOT_TPREL_LO: return "got@tprel@l"; |
| case VK_PPC_GOT_TPREL_HI: return "got@tprel@h"; |
| case VK_PPC_GOT_TPREL_HA: return "got@tprel@ha"; |
| case VK_PPC_GOT_DTPREL: return "got@dtprel"; |
| case VK_PPC_GOT_DTPREL_LO: return "got@dtprel@l"; |
| case VK_PPC_GOT_DTPREL_HI: return "got@dtprel@h"; |
| case VK_PPC_GOT_DTPREL_HA: return "got@dtprel@ha"; |
| case VK_PPC_TLS: return "tls"; |
| case VK_PPC_GOT_TLSGD: return "got@tlsgd"; |
| case VK_PPC_GOT_TLSGD_LO: return "got@tlsgd@l"; |
| case VK_PPC_GOT_TLSGD_HI: return "got@tlsgd@h"; |
| case VK_PPC_GOT_TLSGD_HA: return "got@tlsgd@ha"; |
| case VK_PPC_TLSGD: return "tlsgd"; |
| case VK_PPC_GOT_TLSLD: return "got@tlsld"; |
| case VK_PPC_GOT_TLSLD_LO: return "got@tlsld@l"; |
| case VK_PPC_GOT_TLSLD_HI: return "got@tlsld@h"; |
| case VK_PPC_GOT_TLSLD_HA: return "got@tlsld@ha"; |
| case VK_PPC_TLSLD: return "tlsld"; |
| case VK_PPC_LOCAL: return "local"; |
| case VK_COFF_IMGREL32: return "IMGREL"; |
| case VK_Hexagon_PCREL: return "PCREL"; |
| case VK_Hexagon_LO16: return "LO16"; |
| case VK_Hexagon_HI16: return "HI16"; |
| case VK_Hexagon_GPREL: return "GPREL"; |
| case VK_Hexagon_GD_GOT: return "GDGOT"; |
| case VK_Hexagon_LD_GOT: return "LDGOT"; |
| case VK_Hexagon_GD_PLT: return "GDPLT"; |
| case VK_Hexagon_LD_PLT: return "LDPLT"; |
| case VK_Hexagon_IE: return "IE"; |
| case VK_Hexagon_IE_GOT: return "IEGOT"; |
| case VK_WebAssembly_FUNCTION: return "FUNCTION"; |
| case VK_WebAssembly_TYPEINDEX: return "TYPEINDEX"; |
| case VK_AMDGPU_GOTPCREL32_LO: return "gotpcrel32@lo"; |
| case VK_AMDGPU_GOTPCREL32_HI: return "gotpcrel32@hi"; |
| case VK_AMDGPU_REL32_LO: return "rel32@lo"; |
| case VK_AMDGPU_REL32_HI: return "rel32@hi"; |
| case VK_AMDGPU_REL64: return "rel64"; |
| } |
| llvm_unreachable("Invalid variant kind"); |
| } |
| |
| MCSymbolRefExpr::VariantKind |
| MCSymbolRefExpr::getVariantKindForName(StringRef Name) { |
| return StringSwitch<VariantKind>(Name.lower()) |
| .Case("dtprel", VK_DTPREL) |
| .Case("dtpoff", VK_DTPOFF) |
| .Case("got", VK_GOT) |
| .Case("gotoff", VK_GOTOFF) |
| .Case("gotrel", VK_GOTREL) |
| .Case("gotpcrel", VK_GOTPCREL) |
| .Case("gottpoff", VK_GOTTPOFF) |
| .Case("indntpoff", VK_INDNTPOFF) |
| .Case("ntpoff", VK_NTPOFF) |
| .Case("gotntpoff", VK_GOTNTPOFF) |
| .Case("plt", VK_PLT) |
| .Case("tlscall", VK_TLSCALL) |
| .Case("tlsdesc", VK_TLSDESC) |
| .Case("tlsgd", VK_TLSGD) |
| .Case("tlsld", VK_TLSLD) |
| .Case("tlsldm", VK_TLSLDM) |
| .Case("tpoff", VK_TPOFF) |
| .Case("tprel", VK_TPREL) |
| .Case("tlvp", VK_TLVP) |
| .Case("tlvppage", VK_TLVPPAGE) |
| .Case("tlvppageoff", VK_TLVPPAGEOFF) |
| .Case("page", VK_PAGE) |
| .Case("pageoff", VK_PAGEOFF) |
| .Case("gotpage", VK_GOTPAGE) |
| .Case("gotpageoff", VK_GOTPAGEOFF) |
| .Case("imgrel", VK_COFF_IMGREL32) |
| .Case("secrel32", VK_SECREL) |
| .Case("size", VK_SIZE) |
| .Case("abs8", VK_X86_ABS8) |
| .Case("l", VK_PPC_LO) |
| .Case("h", VK_PPC_HI) |
| .Case("ha", VK_PPC_HA) |
| .Case("high", VK_PPC_HIGH) |
| .Case("higha", VK_PPC_HIGHA) |
| .Case("higher", VK_PPC_HIGHER) |
| .Case("highera", VK_PPC_HIGHERA) |
| .Case("highest", VK_PPC_HIGHEST) |
| .Case("highesta", VK_PPC_HIGHESTA) |
| .Case("got@l", VK_PPC_GOT_LO) |
| .Case("got@h", VK_PPC_GOT_HI) |
| .Case("got@ha", VK_PPC_GOT_HA) |
| .Case("local", VK_PPC_LOCAL) |
| .Case("tocbase", VK_PPC_TOCBASE) |
| .Case("toc", VK_PPC_TOC) |
| .Case("toc@l", VK_PPC_TOC_LO) |
| .Case("toc@h", VK_PPC_TOC_HI) |
| .Case("toc@ha", VK_PPC_TOC_HA) |
| .Case("tls", VK_PPC_TLS) |
| .Case("dtpmod", VK_PPC_DTPMOD) |
| .Case("tprel@l", VK_PPC_TPREL_LO) |
| .Case("tprel@h", VK_PPC_TPREL_HI) |
| .Case("tprel@ha", VK_PPC_TPREL_HA) |
| .Case("tprel@high", VK_PPC_TPREL_HIGH) |
| .Case("tprel@higha", VK_PPC_TPREL_HIGHA) |
| .Case("tprel@higher", VK_PPC_TPREL_HIGHER) |
| .Case("tprel@highera", VK_PPC_TPREL_HIGHERA) |
| .Case("tprel@highest", VK_PPC_TPREL_HIGHEST) |
| .Case("tprel@highesta", VK_PPC_TPREL_HIGHESTA) |
| .Case("dtprel@l", VK_PPC_DTPREL_LO) |
| .Case("dtprel@h", VK_PPC_DTPREL_HI) |
| .Case("dtprel@ha", VK_PPC_DTPREL_HA) |
| .Case("dtprel@high", VK_PPC_DTPREL_HIGH) |
| .Case("dtprel@higha", VK_PPC_DTPREL_HIGHA) |
| .Case("dtprel@higher", VK_PPC_DTPREL_HIGHER) |
| .Case("dtprel@highera", VK_PPC_DTPREL_HIGHERA) |
| .Case("dtprel@highest", VK_PPC_DTPREL_HIGHEST) |
| .Case("dtprel@highesta", VK_PPC_DTPREL_HIGHESTA) |
| .Case("got@tprel", VK_PPC_GOT_TPREL) |
| .Case("got@tprel@l", VK_PPC_GOT_TPREL_LO) |
| .Case("got@tprel@h", VK_PPC_GOT_TPREL_HI) |
| .Case("got@tprel@ha", VK_PPC_GOT_TPREL_HA) |
| .Case("got@dtprel", VK_PPC_GOT_DTPREL) |
| .Case("got@dtprel@l", VK_PPC_GOT_DTPREL_LO) |
| .Case("got@dtprel@h", VK_PPC_GOT_DTPREL_HI) |
| .Case("got@dtprel@ha", VK_PPC_GOT_DTPREL_HA) |
| .Case("got@tlsgd", VK_PPC_GOT_TLSGD) |
| .Case("got@tlsgd@l", VK_PPC_GOT_TLSGD_LO) |
| .Case("got@tlsgd@h", VK_PPC_GOT_TLSGD_HI) |
| .Case("got@tlsgd@ha", VK_PPC_GOT_TLSGD_HA) |
| .Case("got@tlsld", VK_PPC_GOT_TLSLD) |
| .Case("got@tlsld@l", VK_PPC_GOT_TLSLD_LO) |
| .Case("got@tlsld@h", VK_PPC_GOT_TLSLD_HI) |
| .Case("got@tlsld@ha", VK_PPC_GOT_TLSLD_HA) |
| .Case("gdgot", VK_Hexagon_GD_GOT) |
| .Case("gdplt", VK_Hexagon_GD_PLT) |
| .Case("iegot", VK_Hexagon_IE_GOT) |
| .Case("ie", VK_Hexagon_IE) |
| .Case("ldgot", VK_Hexagon_LD_GOT) |
| .Case("ldplt", VK_Hexagon_LD_PLT) |
| .Case("pcrel", VK_Hexagon_PCREL) |
| .Case("none", VK_ARM_NONE) |
| .Case("got_prel", VK_ARM_GOT_PREL) |
| .Case("target1", VK_ARM_TARGET1) |
| .Case("target2", VK_ARM_TARGET2) |
| .Case("prel31", VK_ARM_PREL31) |
| .Case("sbrel", VK_ARM_SBREL) |
| .Case("tlsldo", VK_ARM_TLSLDO) |
| .Case("lo8", VK_AVR_LO8) |
| .Case("hi8", VK_AVR_HI8) |
| .Case("hlo8", VK_AVR_HLO8) |
| .Case("function", VK_WebAssembly_FUNCTION) |
| .Case("typeindex", VK_WebAssembly_TYPEINDEX) |
| .Case("gotpcrel32@lo", VK_AMDGPU_GOTPCREL32_LO) |
| .Case("gotpcrel32@hi", VK_AMDGPU_GOTPCREL32_HI) |
| .Case("rel32@lo", VK_AMDGPU_REL32_LO) |
| .Case("rel32@hi", VK_AMDGPU_REL32_HI) |
| .Case("rel64", VK_AMDGPU_REL64) |
| .Default(VK_Invalid); |
| } |
| |
| void MCSymbolRefExpr::printVariantKind(raw_ostream &OS) const { |
| if (UseParensForSymbolVariant) |
| OS << '(' << MCSymbolRefExpr::getVariantKindName(getKind()) << ')'; |
| else |
| OS << '@' << MCSymbolRefExpr::getVariantKindName(getKind()); |
| } |
| |
| /* *** */ |
| |
| void MCTargetExpr::anchor() {} |
| |
| /* *** */ |
| |
| bool MCExpr::evaluateAsAbsolute(int64_t &Res) const { |
| return evaluateAsAbsolute(Res, nullptr, nullptr, nullptr); |
| } |
| |
| bool MCExpr::evaluateAsAbsolute(int64_t &Res, |
| const MCAsmLayout &Layout) const { |
| return evaluateAsAbsolute(Res, &Layout.getAssembler(), &Layout, nullptr); |
| } |
| |
| 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, nullptr, nullptr); |
| } |
| |
| bool MCExpr::evaluateAsAbsolute(int64_t &Res, const MCAssembler *Asm) const { |
| return evaluateAsAbsolute(Res, Asm, nullptr, nullptr); |
| } |
| |
| bool MCExpr::evaluateKnownAbsolute(int64_t &Res, |
| const MCAsmLayout &Layout) const { |
| return evaluateAsAbsolute(Res, &Layout.getAssembler(), &Layout, nullptr, |
| true); |
| } |
| |
| bool MCExpr::evaluateAsAbsolute(int64_t &Res, const MCAssembler *Asm, |
| const MCAsmLayout *Layout, |
| const SectionAddrMap *Addrs) const { |
| // 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. |
| return evaluateAsAbsolute(Res, Asm, Layout, Addrs, Addrs); |
| } |
| |
| bool MCExpr::evaluateAsAbsolute(int64_t &Res, const MCAssembler *Asm, |
| const MCAsmLayout *Layout, |
| const SectionAddrMap *Addrs, bool InSet) const { |
| MCValue Value; |
| |
| // Fast path constants. |
| if (const MCConstantExpr *CE = dyn_cast<MCConstantExpr>(this)) { |
| Res = CE->getValue(); |
| return true; |
| } |
| |
| bool IsRelocatable = |
| evaluateAsRelocatableImpl(Value, Asm, Layout, nullptr, Addrs, InSet); |
| |
| // Record the current value. |
| Res = Value.getConstant(); |
| |
| return IsRelocatable && Value.isAbsolute(); |
| } |
| |
| /// 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; |
| |
| if (SA.getFragment() == SB.getFragment() && !SA.isVariable() && |
| !SA.isUnset() && !SB.isVariable() && !SB.isUnset()) { |
| Addend += (SA.getOffset() - SB.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 = nullptr; |
| return; |
| } |
| |
| if (!Layout) |
| return; |
| |
| const MCSection &SecA = *SA.getFragment()->getParent(); |
| const MCSection &SecB = *SB.getFragment()->getParent(); |
| |
| if ((&SecA != &SecB) && !Addrs) |
| return; |
| |
| // Eagerly evaluate. |
| Addend += Layout->getSymbolOffset(A->getSymbol()) - |
| Layout->getSymbolOffset(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 = nullptr; |
| } |
| |
| /// 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. Do not do this if |
| // the backend requires this to be emitted as individual relocations, unless |
| // the InSet flag is set to get the current difference anyway (used for |
| // example to calculate symbol sizes). |
| if (Asm && |
| (InSet || !Asm->getBackend().requiresDiffExpressionRelocations())) { |
| // 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; |
| |
| Res = MCValue::get(A, B, Result_Cst); |
| return true; |
| } |
| |
| bool MCExpr::evaluateAsRelocatable(MCValue &Res, |
| const MCAsmLayout *Layout, |
| const MCFixup *Fixup) const { |
| MCAssembler *Assembler = Layout ? &Layout->getAssembler() : nullptr; |
| return evaluateAsRelocatableImpl(Res, Assembler, Layout, Fixup, nullptr, |
| false); |
| } |
| |
| bool MCExpr::evaluateAsValue(MCValue &Res, const MCAsmLayout &Layout) const { |
| MCAssembler *Assembler = &Layout.getAssembler(); |
| return evaluateAsRelocatableImpl(Res, Assembler, &Layout, nullptr, nullptr, |
| true); |
| } |
| |
| static bool canExpand(const MCSymbol &Sym, bool InSet) { |
| const MCExpr *Expr = Sym.getVariableValue(); |
| const auto *Inner = dyn_cast<MCSymbolRefExpr>(Expr); |
| if (Inner) { |
| if (Inner->getKind() == MCSymbolRefExpr::VK_WEAKREF) |
| return false; |
| } |
| |
| if (InSet) |
| return true; |
| return !Sym.isInSection(); |
| } |
| |
| bool MCExpr::evaluateAsRelocatableImpl(MCValue &Res, const MCAssembler *Asm, |
| const MCAsmLayout *Layout, |
| const MCFixup *Fixup, |
| const SectionAddrMap *Addrs, |
| bool InSet) const { |
| ++stats::MCExprEvaluate; |
| |
| switch (getKind()) { |
| case Target: |
| return cast<MCTargetExpr>(this)->evaluateAsRelocatableImpl(Res, Layout, |
| Fixup); |
| |
| 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 && |
| canExpand(Sym, InSet)) { |
| bool IsMachO = SRE->hasSubsectionsViaSymbols(); |
| if (Sym.getVariableValue()->evaluateAsRelocatableImpl( |
| Res, Asm, Layout, Fixup, Addrs, InSet || IsMachO)) { |
| if (!IsMachO) |
| return true; |
| |
| const MCSymbolRefExpr *A = Res.getSymA(); |
| const MCSymbolRefExpr *B = Res.getSymB(); |
| // FIXME: This is small hack. Given |
| // a = b + 4 |
| // .long a |
| // the OS X assembler will completely drop the 4. We should probably |
| // include it in the relocation or produce an error if that is not |
| // possible. |
| // Allow constant expressions. |
| if (!A && !B) |
| return true; |
| // Allows aliases with zero offset. |
| if (Res.getConstant() == 0 && (!A || !B)) |
| return true; |
| } |
| } |
| |
| Res = MCValue::get(SRE, nullptr, 0); |
| return true; |
| } |
| |
| case Unary: { |
| const MCUnaryExpr *AUE = cast<MCUnaryExpr>(this); |
| MCValue Value; |
| |
| if (!AUE->getSubExpr()->evaluateAsRelocatableImpl(Value, Asm, Layout, Fixup, |
| 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; |
| |
| // The cast avoids undefined behavior if the constant is INT64_MIN. |
| Res = MCValue::get(Value.getSymB(), Value.getSymA(), |
| -(uint64_t)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, Fixup, |
| Addrs, InSet) || |
| !ABE->getRHS()->evaluateAsRelocatableImpl(RHSValue, Asm, Layout, Fixup, |
| Addrs, InSet)) { |
| // Check if both are Target Expressions, see if we can compare them. |
| if (const MCTargetExpr *L = dyn_cast<MCTargetExpr>(ABE->getLHS())) |
| if (const MCTargetExpr *R = cast<MCTargetExpr>(ABE->getRHS())) { |
| switch (ABE->getOpcode()) { |
| case MCBinaryExpr::EQ: |
| Res = MCValue::get((L->isEqualTo(R)) ? -1 : 0); |
| return true; |
| case MCBinaryExpr::NE: |
| Res = MCValue::get((R->isEqualTo(R)) ? 0 : -1); |
| return true; |
| default: {} |
| } |
| } |
| 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. |
| // The cast avoids undefined behavior if the constant is INT64_MIN. |
| return EvaluateSymbolicAdd(Asm, Layout, Addrs, InSet, LHSValue, |
| RHSValue.getSymB(), RHSValue.getSymA(), |
| -(uint64_t)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 differently from |
| // Apple as. |
| int64_t LHS = LHSValue.getConstant(), RHS = RHSValue.getConstant(); |
| int64_t Result = 0; |
| auto Op = ABE->getOpcode(); |
| switch (Op) { |
| case MCBinaryExpr::AShr: Result = LHS >> RHS; break; |
| case MCBinaryExpr::Add: Result = LHS + RHS; break; |
| case MCBinaryExpr::And: Result = LHS & RHS; break; |
| case MCBinaryExpr::Div: |
| case MCBinaryExpr::Mod: |
| // Handle division by zero. gas just emits a warning and keeps going, |
| // we try to be stricter. |
| // FIXME: Currently the caller of this function has no way to understand |
| // we're bailing out because of 'division by zero'. Therefore, it will |
| // emit a 'expected relocatable expression' error. It would be nice to |
| // change this code to emit a better diagnostic. |
| if (RHS == 0) |
| return false; |
| if (ABE->getOpcode() == MCBinaryExpr::Div) |
| Result = LHS / RHS; |
| else |
| 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::LShr: Result = uint64_t(LHS) >> uint64_t(RHS); break; |
| case MCBinaryExpr::LT: Result = LHS < RHS; break; |
| case MCBinaryExpr::LTE: 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 = uint64_t(LHS) << uint64_t(RHS); break; |
| case MCBinaryExpr::Sub: Result = LHS - RHS; break; |
| case MCBinaryExpr::Xor: Result = LHS ^ RHS; break; |
| } |
| |
| switch (Op) { |
| default: |
| Res = MCValue::get(Result); |
| break; |
| case MCBinaryExpr::EQ: |
| case MCBinaryExpr::GT: |
| case MCBinaryExpr::GTE: |
| case MCBinaryExpr::LT: |
| case MCBinaryExpr::LTE: |
| case MCBinaryExpr::NE: |
| // A comparison operator returns a -1 if true and 0 if false. |
| Res = MCValue::get(Result ? -1 : 0); |
| break; |
| } |
| |
| return true; |
| } |
| } |
| |
| llvm_unreachable("Invalid assembly expression kind!"); |
| } |
| |
| MCFragment *MCExpr::findAssociatedFragment() const { |
| switch (getKind()) { |
| case Target: |
| // We never look through target specific expressions. |
| return cast<MCTargetExpr>(this)->findAssociatedFragment(); |
| |
| case Constant: |
| return MCSymbol::AbsolutePseudoFragment; |
| |
| case SymbolRef: { |
| const MCSymbolRefExpr *SRE = cast<MCSymbolRefExpr>(this); |
| const MCSymbol &Sym = SRE->getSymbol(); |
| return Sym.getFragment(); |
| } |
| |
| case Unary: |
| return cast<MCUnaryExpr>(this)->getSubExpr()->findAssociatedFragment(); |
| |
| case Binary: { |
| const MCBinaryExpr *BE = cast<MCBinaryExpr>(this); |
| MCFragment *LHS_F = BE->getLHS()->findAssociatedFragment(); |
| MCFragment *RHS_F = BE->getRHS()->findAssociatedFragment(); |
| |
| // If either is absolute, return the other. |
| if (LHS_F == MCSymbol::AbsolutePseudoFragment) |
| return RHS_F; |
| if (RHS_F == MCSymbol::AbsolutePseudoFragment) |
| return LHS_F; |
| |
| // Not always correct, but probably the best we can do without more context. |
| if (BE->getOpcode() == MCBinaryExpr::Sub) |
| return MCSymbol::AbsolutePseudoFragment; |
| |
| // Otherwise, return the first non-null fragment. |
| return LHS_F ? LHS_F : RHS_F; |
| } |
| } |
| |
| llvm_unreachable("Invalid assembly expression kind!"); |
| } |
