lib/Target/AArch64/MCTargetDesc/AArch64MCExpr.h

   1 //=--- AArch64MCExpr.h - AArch64 specific MC expression classes ---*- C++ -*-=//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 //
   9 // This file describes AArch64-specific MCExprs, used for modifiers like
  10 // ":lo12:" or ":gottprel_g1:".
  11 //
  12 //===----------------------------------------------------------------------===//
  13
  14 #ifndef LLVM_LIB_TARGET_AARCH64_MCTARGETDESC_AARCH64MCEXPR_H
  15 #define LLVM_LIB_TARGET_AARCH64_MCTARGETDESC_AARCH64MCEXPR_H
  16
  17 #include "llvm/MC/MCExpr.h"
  18 #include "llvm/Support/ErrorHandling.h"
  19
  20 namespace llvm {
  21
  22 class AArch64MCExpr : public MCTargetExpr {
  23 public:
  24   enum VariantKind {
  25     // Symbol locations specifying (roughly speaking) what calculation should be
  26     // performed to construct the final address for the relocated
  27     // symbol. E.g. direct, via the GOT, ...
  28     VK_ABS      = 0x001,
  29     VK_SABS     = 0x002,
  30     VK_PREL     = 0x003,
  31     VK_GOT      = 0x004,
  32     VK_DTPREL   = 0x005,
  33     VK_GOTTPREL = 0x006,
  34     VK_TPREL    = 0x007,
  35     VK_TLSDESC  = 0x008,
  36     VK_SECREL   = 0x009,
  37     VK_SymLocBits = 0x00f,
  38
  39     // Variants specifying which part of the final address calculation is
  40     // used. E.g. the low 12 bits for an ADD/LDR, the middle 16 bits for a
  41     // MOVZ/MOVK.
  42     VK_PAGE     = 0x010,
  43     VK_PAGEOFF  = 0x020,
  44     VK_HI12     = 0x030,
  45     VK_G0       = 0x040,
  46     VK_G1       = 0x050,
  47     VK_G2       = 0x060,
  48     VK_G3       = 0x070,
  49     VK_AddressFragBits = 0x0f0,
  50
  51     // Whether the final relocation is a checked one (where a linker should
  52     // perform a range-check on the final address) or not. Note that this field
  53     // is unfortunately sometimes omitted from the assembly syntax. E.g. :lo12:
  54     // on its own is a non-checked relocation. We side with ELF on being
  55     // explicit about this!
  56     VK_NC       = 0x100,
  57
  58     // Convenience definitions for referring to specific textual representations
  59     // of relocation specifiers. Note that this means the "_NC" is sometimes
  60     // omitted in line with assembly syntax here (VK_LO12 rather than VK_LO12_NC
  61     // since a user would write ":lo12:").
  62     VK_CALL              = VK_ABS,
  63     VK_ABS_PAGE          = VK_ABS      | VK_PAGE,
  64     VK_ABS_PAGE_NC       = VK_ABS      | VK_PAGE    | VK_NC,
  65     VK_ABS_G3            = VK_ABS      | VK_G3,
  66     VK_ABS_G2            = VK_ABS      | VK_G2,
  67     VK_ABS_G2_S          = VK_SABS     | VK_G2,
  68     VK_ABS_G2_NC         = VK_ABS      | VK_G2      | VK_NC,
  69     VK_ABS_G1            = VK_ABS      | VK_G1,
  70     VK_ABS_G1_S          = VK_SABS     | VK_G1,
  71     VK_ABS_G1_NC         = VK_ABS      | VK_G1      | VK_NC,
  72     VK_ABS_G0            = VK_ABS      | VK_G0,
  73     VK_ABS_G0_S          = VK_SABS     | VK_G0,
  74     VK_ABS_G0_NC         = VK_ABS      | VK_G0      | VK_NC,
  75     VK_LO12              = VK_ABS      | VK_PAGEOFF | VK_NC,
  76     VK_PREL_G3           = VK_PREL     | VK_G3,
  77     VK_PREL_G2           = VK_PREL     | VK_G2,
  78     VK_PREL_G2_NC        = VK_PREL     | VK_G2      | VK_NC,
  79     VK_PREL_G1           = VK_PREL     | VK_G1,
  80     VK_PREL_G1_NC        = VK_PREL     | VK_G1      | VK_NC,
  81     VK_PREL_G0           = VK_PREL     | VK_G0,
  82     VK_PREL_G0_NC        = VK_PREL     | VK_G0      | VK_NC,
  83     VK_GOT_LO12          = VK_GOT      | VK_PAGEOFF | VK_NC,
  84     VK_GOT_PAGE          = VK_GOT      | VK_PAGE,
  85     VK_DTPREL_G2         = VK_DTPREL   | VK_G2,
  86     VK_DTPREL_G1         = VK_DTPREL   | VK_G1,
  87     VK_DTPREL_G1_NC      = VK_DTPREL   | VK_G1      | VK_NC,
  88     VK_DTPREL_G0         = VK_DTPREL   | VK_G0,
  89     VK_DTPREL_G0_NC      = VK_DTPREL   | VK_G0      | VK_NC,
  90     VK_DTPREL_HI12       = VK_DTPREL   | VK_HI12,
  91     VK_DTPREL_LO12       = VK_DTPREL   | VK_PAGEOFF,
  92     VK_DTPREL_LO12_NC    = VK_DTPREL   | VK_PAGEOFF | VK_NC,
  93     VK_GOTTPREL_PAGE     = VK_GOTTPREL | VK_PAGE,
  94     VK_GOTTPREL_LO12_NC  = VK_GOTTPREL | VK_PAGEOFF | VK_NC,
  95     VK_GOTTPREL_G1       = VK_GOTTPREL | VK_G1,
  96     VK_GOTTPREL_G0_NC    = VK_GOTTPREL | VK_G0      | VK_NC,
  97     VK_TPREL_G2          = VK_TPREL    | VK_G2,
  98     VK_TPREL_G1          = VK_TPREL    | VK_G1,
  99     VK_TPREL_G1_NC       = VK_TPREL    | VK_G1      | VK_NC,
 100     VK_TPREL_G0          = VK_TPREL    | VK_G0,
 101     VK_TPREL_G0_NC       = VK_TPREL    | VK_G0      | VK_NC,
 102     VK_TPREL_HI12        = VK_TPREL    | VK_HI12,
 103     VK_TPREL_LO12        = VK_TPREL    | VK_PAGEOFF,
 104     VK_TPREL_LO12_NC     = VK_TPREL    | VK_PAGEOFF | VK_NC,
 105     VK_TLSDESC_LO12      = VK_TLSDESC  | VK_PAGEOFF,
 106     VK_TLSDESC_PAGE      = VK_TLSDESC  | VK_PAGE,
 107     VK_SECREL_LO12       = VK_SECREL   | VK_PAGEOFF,
 108     VK_SECREL_HI12       = VK_SECREL   | VK_HI12,
 109
 110     VK_INVALID  = 0xfff
 111   };
 112
 113 private:
 114   const MCExpr *Expr;
 115   const VariantKind Kind;
 116
 117   explicit AArch64MCExpr(const MCExpr *Expr, VariantKind Kind)
 118     : Expr(Expr), Kind(Kind) {}
 119
 120 public:
 121   /// @name Construction
 122   /// @{
 123
 124   static const AArch64MCExpr *create(const MCExpr *Expr, VariantKind Kind,
 125                                    MCContext &Ctx);
 126
 127   /// @}
 128   /// @name Accessors
 129   /// @{
 130
 131   /// Get the kind of this expression.
 132   VariantKind getKind() const { return Kind; }
 133
 134   /// Get the expression this modifier applies to.
 135   const MCExpr *getSubExpr() const { return Expr; }
 136
 137   /// @}
 138   /// @name VariantKind information extractors.
 139   /// @{
 140
 141   static VariantKind getSymbolLoc(VariantKind Kind) {
 142     return static_cast<VariantKind>(Kind & VK_SymLocBits);
 143   }
 144
 145   static VariantKind getAddressFrag(VariantKind Kind) {
 146     return static_cast<VariantKind>(Kind & VK_AddressFragBits);
 147   }
 148
 149   static bool isNotChecked(VariantKind Kind) { return Kind & VK_NC; }
 150
 151   /// @}
 152
 153   /// Convert the variant kind into an ELF-appropriate modifier
 154   /// (e.g. ":got:", ":lo12:").
 155   StringRef getVariantKindName() const;
 156
 157   void printImpl(raw_ostream &OS, const MCAsmInfo *MAI) const override;
 158
 159   void visitUsedExpr(MCStreamer &Streamer) const override;
 160
 161   MCFragment *findAssociatedFragment() const override;
 162
 163   bool evaluateAsRelocatableImpl(MCValue &Res, const MCAsmLayout *Layout,
 164                                  const MCFixup *Fixup) const override;
 165
 166   void fixELFSymbolsInTLSFixups(MCAssembler &Asm) const override;
 167
 168   static bool classof(const MCExpr *E) {
 169     return E->getKind() == MCExpr::Target;
 170   }
 171
 172   static bool classof(const AArch64MCExpr *) { return true; }
 173 };
 174 } // end namespace llvm
 175
 176 #endif