1//=--- AArch64MCExpr.h - AArch64 specific MC expression classes ---*- C++ -*-=//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This file describes AArch64-specific MCExprs, used for modifiers like
11// ":lo12:" or ":gottprel_g1:".
12//
13//===----------------------------------------------------------------------===//
14
15#ifndef LLVM_LIB_TARGET_AARCH64_MCTARGETDESC_AARCH64MCEXPR_H
16#define LLVM_LIB_TARGET_AARCH64_MCTARGETDESC_AARCH64MCEXPR_H
17
18#include "llvm/MC/MCExpr.h"
19#include "llvm/Support/ErrorHandling.h"
20
21namespace llvm {
22
23class AArch64MCExpr : public MCTargetExpr {
24public:
25  enum VariantKind {
26    VK_NONE     = 0x000,
27
28    // Symbol locations specifying (roughly speaking) what calculation should be
29    // performed to construct the final address for the relocated
30    // symbol. E.g. direct, via the GOT, ...
31    VK_ABS      = 0x001,
32    VK_SABS     = 0x002,
33    VK_GOT      = 0x003,
34    VK_DTPREL   = 0x004,
35    VK_GOTTPREL = 0x005,
36    VK_TPREL    = 0x006,
37    VK_TLSDESC  = 0x007,
38    VK_SymLocBits = 0x00f,
39
40    // Variants specifying which part of the final address calculation is
41    // used. E.g. the low 12 bits for an ADD/LDR, the middle 16 bits for a
42    // MOVZ/MOVK.
43    VK_PAGE     = 0x010,
44    VK_PAGEOFF  = 0x020,
45    VK_HI12     = 0x030,
46    VK_G0       = 0x040,
47    VK_G1       = 0x050,
48    VK_G2       = 0x060,
49    VK_G3       = 0x070,
50    VK_AddressFragBits = 0x0f0,
51
52    // Whether the final relocation is a checked one (where a linker should
53    // perform a range-check on the final address) or not. Note that this field
54    // is unfortunately sometimes omitted from the assembly syntax. E.g. :lo12:
55    // on its own is a non-checked relocation. We side with ELF on being
56    // explicit about this!
57    VK_NC       = 0x100,
58
59    // Convenience definitions for referring to specific textual representations
60    // of relocation specifiers. Note that this means the "_NC" is sometimes
61    // omitted in line with assembly syntax here (VK_LO12 rather than VK_LO12_NC
62    // since a user would write ":lo12:").
63    VK_CALL              = VK_ABS,
64    VK_ABS_PAGE          = VK_ABS      | VK_PAGE,
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_GOT_LO12          = VK_GOT      | VK_PAGEOFF | VK_NC,
77    VK_GOT_PAGE          = VK_GOT      | VK_PAGE,
78    VK_DTPREL_G2         = VK_DTPREL   | VK_G2,
79    VK_DTPREL_G1         = VK_DTPREL   | VK_G1,
80    VK_DTPREL_G1_NC      = VK_DTPREL   | VK_G1      | VK_NC,
81    VK_DTPREL_G0         = VK_DTPREL   | VK_G0,
82    VK_DTPREL_G0_NC      = VK_DTPREL   | VK_G0      | VK_NC,
83    VK_DTPREL_HI12       = VK_DTPREL   | VK_HI12,
84    VK_DTPREL_LO12       = VK_DTPREL   | VK_PAGEOFF,
85    VK_DTPREL_LO12_NC    = VK_DTPREL   | VK_PAGEOFF | VK_NC,
86    VK_GOTTPREL_PAGE     = VK_GOTTPREL | VK_PAGE,
87    VK_GOTTPREL_LO12_NC  = VK_GOTTPREL | VK_PAGEOFF | VK_NC,
88    VK_GOTTPREL_G1       = VK_GOTTPREL | VK_G1,
89    VK_GOTTPREL_G0_NC    = VK_GOTTPREL | VK_G0      | VK_NC,
90    VK_TPREL_G2          = VK_TPREL    | VK_G2,
91    VK_TPREL_G1          = VK_TPREL    | VK_G1,
92    VK_TPREL_G1_NC       = VK_TPREL    | VK_G1      | VK_NC,
93    VK_TPREL_G0          = VK_TPREL    | VK_G0,
94    VK_TPREL_G0_NC       = VK_TPREL    | VK_G0      | VK_NC,
95    VK_TPREL_HI12        = VK_TPREL    | VK_HI12,
96    VK_TPREL_LO12        = VK_TPREL    | VK_PAGEOFF,
97    VK_TPREL_LO12_NC     = VK_TPREL    | VK_PAGEOFF | VK_NC,
98    VK_TLSDESC_LO12      = VK_TLSDESC  | VK_PAGEOFF | VK_NC,
99    VK_TLSDESC_PAGE      = VK_TLSDESC  | VK_PAGE,
100
101    VK_INVALID  = 0xfff
102  };
103
104private:
105  const MCExpr *Expr;
106  const VariantKind Kind;
107
108  explicit AArch64MCExpr(const MCExpr *Expr, VariantKind Kind)
109    : Expr(Expr), Kind(Kind) {}
110
111public:
112  /// @name Construction
113  /// @{
114
115  static const AArch64MCExpr *create(const MCExpr *Expr, VariantKind Kind,
116                                   MCContext &Ctx);
117
118  /// @}
119  /// @name Accessors
120  /// @{
121
122  /// Get the kind of this expression.
123  VariantKind getKind() const { return Kind; }
124
125  /// Get the expression this modifier applies to.
126  const MCExpr *getSubExpr() const { return Expr; }
127
128  /// @}
129  /// @name VariantKind information extractors.
130  /// @{
131
132  static VariantKind getSymbolLoc(VariantKind Kind) {
133    return static_cast<VariantKind>(Kind & VK_SymLocBits);
134  }
135
136  static VariantKind getAddressFrag(VariantKind Kind) {
137    return static_cast<VariantKind>(Kind & VK_AddressFragBits);
138  }
139
140  static bool isNotChecked(VariantKind Kind) { return Kind & VK_NC; }
141
142  /// @}
143
144  /// Convert the variant kind into an ELF-appropriate modifier
145  /// (e.g. ":got:", ":lo12:").
146  StringRef getVariantKindName() const;
147
148  void printImpl(raw_ostream &OS, const MCAsmInfo *MAI) const override;
149
150  void visitUsedExpr(MCStreamer &Streamer) const override;
151
152  MCFragment *findAssociatedFragment() const override;
153
154  bool evaluateAsRelocatableImpl(MCValue &Res, const MCAsmLayout *Layout,
155                                 const MCFixup *Fixup) const override;
156
157  void fixELFSymbolsInTLSFixups(MCAssembler &Asm) const override;
158
159  static bool classof(const MCExpr *E) {
160    return E->getKind() == MCExpr::Target;
161  }
162
163  static bool classof(const AArch64MCExpr *) { return true; }
164};
165} // end namespace llvm
166
167#endif
168