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 "Utils/AArch64BaseInfo.h"
18#include "llvm/MC/MCExpr.h"
19#include "llvm/Support/Casting.h"
20#include "llvm/Support/ErrorHandling.h"
21
22namespace llvm {
23
24class AArch64MCExpr : public MCTargetExpr {
25public:
26  enum VariantKind {
27    // Symbol locations specifying (roughly speaking) what calculation should be
28    // performed to construct the final address for the relocated
29    // symbol. E.g. direct, via the GOT, ...
30    VK_ABS      = 0x001,
31    VK_SABS     = 0x002,
32    VK_PREL     = 0x003,
33    VK_GOT      = 0x004,
34    VK_DTPREL   = 0x005,
35    VK_GOTTPREL = 0x006,
36    VK_TPREL    = 0x007,
37    VK_TLSDESC  = 0x008,
38    VK_SECREL   = 0x009,
39    VK_AUTH     = 0x00a,
40    VK_AUTHADDR = 0x00b,
41    VK_SymLocBits = 0x00f,
42
43    // Variants specifying which part of the final address calculation is
44    // used. E.g. the low 12 bits for an ADD/LDR, the middle 16 bits for a
45    // MOVZ/MOVK.
46    VK_PAGE     = 0x010,
47    VK_PAGEOFF  = 0x020,
48    VK_HI12     = 0x030,
49    VK_G0       = 0x040,
50    VK_G1       = 0x050,
51    VK_G2       = 0x060,
52    VK_G3       = 0x070,
53    VK_LO15     = 0x080,
54    VK_AddressFragBits = 0x0f0,
55
56    // Whether the final relocation is a checked one (where a linker should
57    // perform a range-check on the final address) or not. Note that this field
58    // is unfortunately sometimes omitted from the assembly syntax. E.g. :lo12:
59    // on its own is a non-checked relocation. We side with ELF on being
60    // explicit about this!
61    VK_NC       = 0x100,
62
63    // Convenience definitions for referring to specific textual representations
64    // of relocation specifiers. Note that this means the "_NC" is sometimes
65    // omitted in line with assembly syntax here (VK_LO12 rather than VK_LO12_NC
66    // since a user would write ":lo12:").
67    VK_CALL              = VK_ABS,
68    VK_ABS_PAGE          = VK_ABS      | VK_PAGE,
69    VK_ABS_PAGE_NC       = VK_ABS      | VK_PAGE    | VK_NC,
70    VK_ABS_G3            = VK_ABS      | VK_G3,
71    VK_ABS_G2            = VK_ABS      | VK_G2,
72    VK_ABS_G2_S          = VK_SABS     | VK_G2,
73    VK_ABS_G2_NC         = VK_ABS      | VK_G2      | VK_NC,
74    VK_ABS_G1            = VK_ABS      | VK_G1,
75    VK_ABS_G1_S          = VK_SABS     | VK_G1,
76    VK_ABS_G1_NC         = VK_ABS      | VK_G1      | VK_NC,
77    VK_ABS_G0            = VK_ABS      | VK_G0,
78    VK_ABS_G0_S          = VK_SABS     | VK_G0,
79    VK_ABS_G0_NC         = VK_ABS      | VK_G0      | VK_NC,
80    VK_LO12              = VK_ABS      | VK_PAGEOFF | VK_NC,
81    VK_PREL_G3           = VK_PREL     | VK_G3,
82    VK_PREL_G2           = VK_PREL     | VK_G2,
83    VK_PREL_G2_NC        = VK_PREL     | VK_G2      | VK_NC,
84    VK_PREL_G1           = VK_PREL     | VK_G1,
85    VK_PREL_G1_NC        = VK_PREL     | VK_G1      | VK_NC,
86    VK_PREL_G0           = VK_PREL     | VK_G0,
87    VK_PREL_G0_NC        = VK_PREL     | VK_G0      | VK_NC,
88    VK_GOT_LO12          = VK_GOT      | VK_PAGEOFF | VK_NC,
89    VK_GOT_PAGE          = VK_GOT      | VK_PAGE,
90    VK_GOT_PAGE_LO15     = VK_GOT      | VK_LO15    | VK_NC,
91    VK_DTPREL_G2         = VK_DTPREL   | VK_G2,
92    VK_DTPREL_G1         = VK_DTPREL   | VK_G1,
93    VK_DTPREL_G1_NC      = VK_DTPREL   | VK_G1      | VK_NC,
94    VK_DTPREL_G0         = VK_DTPREL   | VK_G0,
95    VK_DTPREL_G0_NC      = VK_DTPREL   | VK_G0      | VK_NC,
96    VK_DTPREL_HI12       = VK_DTPREL   | VK_HI12,
97    VK_DTPREL_LO12       = VK_DTPREL   | VK_PAGEOFF,
98    VK_DTPREL_LO12_NC    = VK_DTPREL   | VK_PAGEOFF | VK_NC,
99    VK_GOTTPREL_PAGE     = VK_GOTTPREL | VK_PAGE,
100    VK_GOTTPREL_LO12_NC  = VK_GOTTPREL | VK_PAGEOFF | VK_NC,
101    VK_GOTTPREL_G1       = VK_GOTTPREL | VK_G1,
102    VK_GOTTPREL_G0_NC    = VK_GOTTPREL | VK_G0      | VK_NC,
103    VK_TPREL_G2          = VK_TPREL    | VK_G2,
104    VK_TPREL_G1          = VK_TPREL    | VK_G1,
105    VK_TPREL_G1_NC       = VK_TPREL    | VK_G1      | VK_NC,
106    VK_TPREL_G0          = VK_TPREL    | VK_G0,
107    VK_TPREL_G0_NC       = VK_TPREL    | VK_G0      | VK_NC,
108    VK_TPREL_HI12        = VK_TPREL    | VK_HI12,
109    VK_TPREL_LO12        = VK_TPREL    | VK_PAGEOFF,
110    VK_TPREL_LO12_NC     = VK_TPREL    | VK_PAGEOFF | VK_NC,
111    VK_TLSDESC_LO12      = VK_TLSDESC  | VK_PAGEOFF,
112    VK_TLSDESC_PAGE      = VK_TLSDESC  | VK_PAGE,
113    VK_SECREL_LO12       = VK_SECREL   | VK_PAGEOFF,
114    VK_SECREL_HI12       = VK_SECREL   | VK_HI12,
115
116    VK_INVALID  = 0xfff
117  };
118
119private:
120  const MCExpr *Expr;
121  const VariantKind Kind;
122
123protected:
124  explicit AArch64MCExpr(const MCExpr *Expr, VariantKind Kind)
125    : Expr(Expr), Kind(Kind) {}
126
127public:
128  /// @name Construction
129  /// @{
130
131  static const AArch64MCExpr *create(const MCExpr *Expr, VariantKind Kind,
132                                   MCContext &Ctx);
133
134  /// @}
135  /// @name Accessors
136  /// @{
137
138  /// Get the kind of this expression.
139  VariantKind getKind() const { return Kind; }
140
141  /// Get the expression this modifier applies to.
142  const MCExpr *getSubExpr() const { return Expr; }
143
144  /// @}
145  /// @name VariantKind information extractors.
146  /// @{
147
148  static VariantKind getSymbolLoc(VariantKind Kind) {
149    return static_cast<VariantKind>(Kind & VK_SymLocBits);
150  }
151
152  static VariantKind getAddressFrag(VariantKind Kind) {
153    return static_cast<VariantKind>(Kind & VK_AddressFragBits);
154  }
155
156  static bool isNotChecked(VariantKind Kind) { return Kind & VK_NC; }
157
158  /// @}
159
160  /// Convert the variant kind into an ELF-appropriate modifier
161  /// (e.g. ":got:", ":lo12:").
162  StringRef getVariantKindName() const;
163
164  void printImpl(raw_ostream &OS, const MCAsmInfo *MAI) const override;
165
166  void visitUsedExpr(MCStreamer &Streamer) const override;
167
168  MCFragment *findAssociatedFragment() const override;
169
170  bool evaluateAsRelocatableImpl(MCValue &Res, const MCAsmLayout *Layout,
171                                 const MCFixup *Fixup) const override;
172
173  void fixELFSymbolsInTLSFixups(MCAssembler &Asm) const override;
174
175  static bool classof(const MCExpr *E) {
176    return E->getKind() == MCExpr::Target;
177  }
178};
179
180class AArch64AuthMCExpr final : public AArch64MCExpr {
181  uint16_t Discriminator;
182  AArch64PACKey::ID Key;
183
184  explicit AArch64AuthMCExpr(const MCExpr *Expr, uint16_t Discriminator,
185                             AArch64PACKey::ID Key, bool HasAddressDiversity)
186      : AArch64MCExpr(Expr, HasAddressDiversity ? VK_AUTHADDR : VK_AUTH),
187        Discriminator(Discriminator), Key(Key) {}
188
189public:
190  static const AArch64AuthMCExpr *
191  create(const MCExpr *Expr, uint16_t Discriminator, AArch64PACKey::ID Key,
192         bool HasAddressDiversity, MCContext &Ctx);
193
194  AArch64PACKey::ID getKey() const { return Key; }
195  uint16_t getDiscriminator() const { return Discriminator; }
196  bool hasAddressDiversity() const { return getKind() == VK_AUTHADDR; }
197
198  void printImpl(raw_ostream &OS, const MCAsmInfo *MAI) const override;
199
200  void visitUsedExpr(MCStreamer &Streamer) const override;
201
202  MCFragment *findAssociatedFragment() const override;
203
204  bool evaluateAsRelocatableImpl(MCValue &Res, const MCAsmLayout *Layout,
205                                 const MCFixup *Fixup) const override;
206
207  static bool classof(const MCExpr *E) {
208    return isa<AArch64MCExpr>(E) && classof(cast<AArch64MCExpr>(E));
209  }
210
211  static bool classof(const AArch64MCExpr *E) {
212    return E->getKind() == VK_AUTH || E->getKind() == VK_AUTHADDR;
213  }
214};
215} // end namespace llvm
216
217#endif
218