//===- MCExpr.cpp - Assembly Level Expression 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/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 #include 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(this)->printImpl(OS, MAI); case MCExpr::Constant: { auto Value = cast(*this).getValue(); auto PrintInHex = cast(*this).useHexFormat(); auto SizeInBytes = cast(*this).getSizeInBytes(); if (Value < 0 && MAI && !MAI->supportsSignedData()) PrintInHex = true; if (PrintInHex) switch (SizeInBytes) { default: OS << "0x" << Twine::utohexstr(Value); break; case 1: OS << format("0x%02" PRIx64, Value); break; case 2: OS << format("0x%04" PRIx64, Value); break; case 4: OS << format("0x%08" PRIx64, Value); break; case 8: OS << format("0x%016" PRIx64, Value); break; } else OS << Value; return; } case MCExpr::SymbolRef: { const MCSymbolRefExpr &SRE = cast(*this); const MCSymbol &Sym = SRE.getSymbol(); // Parenthesize names that start with $ so that they don't look like // absolute names. bool UseParens = MAI && MAI->useParensForDollarSignNames() && !InParens && !Sym.getName().empty() && Sym.getName()[0] == '$'; if (UseParens) { OS << '('; Sym.print(OS, MAI); OS << ')'; } else Sym.print(OS, MAI); const MCSymbolRefExpr::VariantKind Kind = SRE.getKind(); if (Kind != MCSymbolRefExpr::VK_None) { if (MAI && MAI->useParensForSymbolVariant()) // ARM OS << '(' << MCSymbolRefExpr::getVariantKindName(Kind) << ')'; else OS << '@' << MCSymbolRefExpr::getVariantKindName(Kind); } return; } case MCExpr::Unary: { const MCUnaryExpr &UE = cast(*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(*this); // Only print parens around the LHS if it is non-trivial. if (isa(BE.getLHS()) || isa(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(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::OrNot: 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(BE.getRHS()) || isa(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, bool PrintInHex, unsigned SizeInBytes) { return new (Ctx) MCConstantExpr(Value, PrintInHex, SizeInBytes); } /* *** */ MCSymbolRefExpr::MCSymbolRefExpr(const MCSymbol *Symbol, VariantKind Kind, const MCAsmInfo *MAI, SMLoc Loc) : MCExpr(MCExpr::SymbolRef, Loc, encodeSubclassData(Kind, 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 "<>"; case VK_None: return "<>"; 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_PCREL: return "PCREL"; case VK_GOTPCREL: return "GOTPCREL"; case VK_GOTPCREL_NORELAX: return "GOTPCREL_NORELAX"; 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_X86_PLTOFF: return "PLTOFF"; 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_AVR_PM: return "pm"; 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_U: return "u"; case VK_PPC_L: return "l"; 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_AIX_TLSGD: return "gd"; case VK_PPC_AIX_TLSGDM: return "m"; case VK_PPC_AIX_TLSIE: return "ie"; case VK_PPC_AIX_TLSLE: return "le"; 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_GOT_PCREL: return "got@pcrel"; case VK_PPC_GOT_TLSGD_PCREL: return "got@tlsgd@pcrel"; case VK_PPC_GOT_TLSLD_PCREL: return "got@tlsld@pcrel"; case VK_PPC_GOT_TPREL_PCREL: return "got@tprel@pcrel"; case VK_PPC_TLS_PCREL: return "tls@pcrel"; case VK_PPC_TLSLD: return "tlsld"; case VK_PPC_LOCAL: return "local"; case VK_PPC_NOTOC: return "notoc"; case VK_PPC_PCREL_OPT: return "<>"; case VK_COFF_IMGREL32: return "IMGREL"; 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_WASM_TYPEINDEX: return "TYPEINDEX"; case VK_WASM_MBREL: return "MBREL"; case VK_WASM_TLSREL: return "TLSREL"; case VK_WASM_TBREL: return "TBREL"; case VK_WASM_GOT_TLS: return "GOT@TLS"; case VK_WASM_FUNCINDEX: return "FUNCINDEX"; 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"; case VK_AMDGPU_ABS32_LO: return "abs32@lo"; case VK_AMDGPU_ABS32_HI: return "abs32@hi"; case VK_VE_HI32: return "hi"; case VK_VE_LO32: return "lo"; case VK_VE_PC_HI32: return "pc_hi"; case VK_VE_PC_LO32: return "pc_lo"; case VK_VE_GOT_HI32: return "got_hi"; case VK_VE_GOT_LO32: return "got_lo"; case VK_VE_GOTOFF_HI32: return "gotoff_hi"; case VK_VE_GOTOFF_LO32: return "gotoff_lo"; case VK_VE_PLT_HI32: return "plt_hi"; case VK_VE_PLT_LO32: return "plt_lo"; case VK_VE_TLS_GD_HI32: return "tls_gd_hi"; case VK_VE_TLS_GD_LO32: return "tls_gd_lo"; case VK_VE_TPOFF_HI32: return "tpoff_hi"; case VK_VE_TPOFF_LO32: return "tpoff_lo"; } llvm_unreachable("Invalid variant kind"); } MCSymbolRefExpr::VariantKind MCSymbolRefExpr::getVariantKindForName(StringRef Name) { return StringSwitch(Name.lower()) .Case("dtprel", VK_DTPREL) .Case("dtpoff", VK_DTPOFF) .Case("got", VK_GOT) .Case("gotoff", VK_GOTOFF) .Case("gotrel", VK_GOTREL) .Case("pcrel", VK_PCREL) .Case("gotpcrel", VK_GOTPCREL) .Case("gotpcrel_norelax", VK_GOTPCREL_NORELAX) .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("pltoff", VK_X86_PLTOFF) .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("u", VK_PPC_U) .Case("l", VK_PPC_L) .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("got@pcrel", VK_PPC_GOT_PCREL) .Case("got@tlsgd@pcrel", VK_PPC_GOT_TLSGD_PCREL) .Case("got@tlsld@pcrel", VK_PPC_GOT_TLSLD_PCREL) .Case("got@tprel@pcrel", VK_PPC_GOT_TPREL_PCREL) .Case("tls@pcrel", VK_PPC_TLS_PCREL) .Case("notoc", VK_PPC_NOTOC) .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("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("typeindex", VK_WASM_TYPEINDEX) .Case("tbrel", VK_WASM_TBREL) .Case("mbrel", VK_WASM_MBREL) .Case("tlsrel", VK_WASM_TLSREL) .Case("got@tls", VK_WASM_GOT_TLS) .Case("funcindex", VK_WASM_FUNCINDEX) .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) .Case("abs32@lo", VK_AMDGPU_ABS32_LO) .Case("abs32@hi", VK_AMDGPU_ABS32_HI) .Case("hi", VK_VE_HI32) .Case("lo", VK_VE_LO32) .Case("pc_hi", VK_VE_PC_HI32) .Case("pc_lo", VK_VE_PC_LO32) .Case("got_hi", VK_VE_GOT_HI32) .Case("got_lo", VK_VE_GOT_LO32) .Case("gotoff_hi", VK_VE_GOTOFF_HI32) .Case("gotoff_lo", VK_VE_GOTOFF_LO32) .Case("plt_hi", VK_VE_PLT_HI32) .Case("plt_lo", VK_VE_PLT_LO32) .Case("tls_gd_hi", VK_VE_TLS_GD_HI32) .Case("tls_gd_lo", VK_VE_TLS_GD_LO32) .Case("tpoff_hi", VK_VE_TPOFF_HI32) .Case("tpoff_lo", VK_VE_TPOFF_LO32) .Default(VK_Invalid); } /* *** */ void MCTargetExpr::anchor() {} /* *** */ bool MCExpr::evaluateAsAbsolute(int64_t &Res) const { return evaluateAsAbsolute(Res, nullptr, nullptr, nullptr, false); } bool MCExpr::evaluateAsAbsolute(int64_t &Res, const MCAsmLayout &Layout) const { return evaluateAsAbsolute(Res, &Layout.getAssembler(), &Layout, nullptr, false); } bool MCExpr::evaluateAsAbsolute(int64_t &Res, const MCAsmLayout &Layout, const SectionAddrMap &Addrs) const { // Setting InSet causes us to absolutize differences across sections and that // is what the MachO writer uses Addrs for. return evaluateAsAbsolute(Res, &Layout.getAssembler(), &Layout, &Addrs, true); } bool MCExpr::evaluateAsAbsolute(int64_t &Res, const MCAssembler &Asm) const { return evaluateAsAbsolute(Res, &Asm, nullptr, nullptr, false); } bool MCExpr::evaluateAsAbsolute(int64_t &Res, const MCAssembler *Asm) const { return evaluateAsAbsolute(Res, Asm, nullptr, nullptr, false); } 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, bool InSet) const { MCValue Value; // Fast path constants. if (const MCConstantExpr *CE = dyn_cast(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; auto FinalizeFolding = [&]() { // 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; }; const MCFragment *FA = SA.getFragment(); const MCFragment *FB = SB.getFragment(); const MCSection &SecA = *FA->getParent(); const MCSection &SecB = *FB->getParent(); if ((&SecA != &SecB) && !Addrs) return; // When layout is available, we can generally compute the difference using the // getSymbolOffset path, which also avoids the possible slow fragment walk. // However, linker relaxation may cause incorrect fold of A-B if A and B are // separated by a linker-relaxable instruction. If the section contains // instructions and InSet is false (not expressions in directive like // .size/.fill), disable the fast path. if (Layout && (InSet || !SecA.hasInstructions() || !(Asm->getContext().getTargetTriple().isRISCV() || Asm->getContext().getTargetTriple().isLoongArch()))) { // If both symbols are in the same fragment, return the difference of their // offsets. canGetFragmentOffset(FA) may be false. if (FA == FB && !SA.isVariable() && !SB.isVariable()) { Addend += SA.getOffset() - SB.getOffset(); return FinalizeFolding(); } // One of the symbol involved is part of a fragment being laid out. Quit now // to avoid a self loop. if (!Layout->canGetFragmentOffset(FA) || !Layout->canGetFragmentOffset(FB)) return; // Eagerly evaluate when layout is finalized. Addend += Layout->getSymbolOffset(A->getSymbol()) - Layout->getSymbolOffset(B->getSymbol()); if (Addrs && (&SecA != &SecB)) Addend += (Addrs->lookup(&SecA) - Addrs->lookup(&SecB)); FinalizeFolding(); } else { // When layout is not finalized, our ability to resolve differences between // symbols is limited to specific cases where the fragments between two // symbols (including the fragments the symbols are defined in) are // fixed-size fragments so the difference can be calculated. For example, // this is important when the Subtarget is changed and a new MCDataFragment // is created in the case of foo: instr; .arch_extension ext; instr .if . - // foo. if (SA.isVariable() || SB.isVariable() || FA->getSubsectionNumber() != FB->getSubsectionNumber()) return; // Try to find a constant displacement from FA to FB, add the displacement // between the offset in FA of SA and the offset in FB of SB. bool Reverse = false; if (FA == FB) { Reverse = SA.getOffset() < SB.getOffset(); } else if (!isa(FA)) { Reverse = std::find_if(std::next(FA->getIterator()), SecA.end(), [&](auto &I) { return &I == FB; }) != SecA.end(); } uint64_t SAOffset = SA.getOffset(), SBOffset = SB.getOffset(); int64_t Displacement = SA.getOffset() - SB.getOffset(); if (Reverse) { std::swap(FA, FB); std::swap(SAOffset, SBOffset); Displacement *= -1; } [[maybe_unused]] bool Found = false; // Track whether B is before a relaxable instruction and whether A is after // a relaxable instruction. If SA and SB are separated by a linker-relaxable // instruction, the difference cannot be resolved as it may be changed by // the linker. bool BBeforeRelax = false, AAfterRelax = false; for (auto FI = FB->getIterator(), FE = SecA.end(); FI != FE; ++FI) { auto DF = dyn_cast(FI); if (DF && DF->isLinkerRelaxable()) { if (&*FI != FB || SBOffset != DF->getContents().size()) BBeforeRelax = true; if (&*FI != FA || SAOffset == DF->getContents().size()) AAfterRelax = true; if (BBeforeRelax && AAfterRelax) return; } if (&*FI == FA) { Found = true; break; } int64_t Num; unsigned Count; if (DF) { Displacement += DF->getContents().size(); } else if (auto *AF = dyn_cast(FI); AF && Layout && AF->hasEmitNops() && !Asm->getBackend().shouldInsertExtraNopBytesForCodeAlign( *AF, Count)) { Displacement += Asm->computeFragmentSize(*Layout, *AF); } else if (auto *FF = dyn_cast(FI); FF && FF->getNumValues().evaluateAsAbsolute(Num)) { Displacement += Num * FF->getValueSize(); } else { return; } } // If the previous loop does not find FA, FA must be a dummy fragment not in // the fragment list (which means SA is a pending label (see // flushPendingLabels)). In either case, we can resolve the difference. assert(Found || isa(FA)); Addend += Reverse ? -Displacement : Displacement; FinalizeFolding(); } } /// 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 aggressively 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 MCValue &RHS, 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(); const MCSymbolRefExpr *RHS_A = RHS.getSymA(); const MCSymbolRefExpr *RHS_B = RHS.getSymB(); int64_t RHS_Cst = RHS.getConstant(); if (LHS.getRefKind() != RHS.getRefKind()) return false; // 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; 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) { if (Sym.isWeakExternal()) return false; const MCExpr *Expr = Sym.getVariableValue(); const auto *Inner = dyn_cast(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(this)->evaluateAsRelocatableImpl(Res, Layout, Fixup); case Constant: Res = MCValue::get(cast(this)->getValue()); return true; case SymbolRef: { const MCSymbolRefExpr *SRE = cast(this); const MCSymbol &Sym = SRE->getSymbol(); const auto Kind = SRE->getKind(); // Evaluate recursively if this is a variable. if (Sym.isVariable() && (Kind == MCSymbolRefExpr::VK_None || Layout) && canExpand(Sym, InSet)) { bool IsMachO = SRE->hasSubsectionsViaSymbols(); if (Sym.getVariableValue()->evaluateAsRelocatableImpl( Res, Asm, Layout, Fixup, Addrs, InSet || IsMachO)) { if (Kind != MCSymbolRefExpr::VK_None) { if (Res.isAbsolute()) { Res = MCValue::get(SRE, nullptr, 0); return true; } // If the reference has a variant kind, we can only handle expressions // which evaluate exactly to a single unadorned symbol. Attach the // original VariantKind to SymA of the result. if (Res.getRefKind() != MCSymbolRefExpr::VK_None || !Res.getSymA() || Res.getSymB() || Res.getConstant()) return false; Res = MCValue::get(MCSymbolRefExpr::create(&Res.getSymA()->getSymbol(), Kind, Asm->getContext()), Res.getSymB(), Res.getConstant(), Res.getRefKind()); } 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(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(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(ABE->getLHS())) { if (const MCTargetExpr *R = dyn_cast(ABE->getRHS())) { switch (ABE->getOpcode()) { case MCBinaryExpr::EQ: Res = MCValue::get(L->isEqualTo(R) ? -1 : 0); return true; case MCBinaryExpr::NE: Res = MCValue::get(L->isEqualTo(R) ? 0 : -1); return true; default: break; } } } 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, MCValue::get(RHSValue.getSymB(), RHSValue.getSymA(), -(uint64_t)RHSValue.getConstant(), RHSValue.getRefKind()), Res); case MCBinaryExpr::Add: return EvaluateSymbolicAdd( Asm, Layout, Addrs, InSet, LHSValue, MCValue::get(RHSValue.getSymA(), RHSValue.getSymB(), RHSValue.getConstant(), RHSValue.getRefKind()), 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::OrNot: 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(this)->findAssociatedFragment(); case Constant: return MCSymbol::AbsolutePseudoFragment; case SymbolRef: { const MCSymbolRefExpr *SRE = cast(this); const MCSymbol &Sym = SRE->getSymbol(); return Sym.getFragment(); } case Unary: return cast(this)->getSubExpr()->findAssociatedFragment(); case Binary: { const MCBinaryExpr *BE = cast(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!"); }