AArch64MCExpr.h revision 360784 
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
20namespace llvm {
21
22class AArch64MCExpr : public MCTargetExpr {
23public:
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
113private:
114  const MCExpr *Expr;
115  const VariantKind Kind;
116
117  explicit AArch64MCExpr(const MCExpr *Expr, VariantKind Kind)
118    : Expr(Expr), Kind(Kind) {}
119
120public:
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
177