LLVM  4.0.0
AArch64MCExpr.h
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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"
20 
21 namespace llvm {
22 
23 class AArch64MCExpr : public MCTargetExpr {
24 public:
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,
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:").
100 
101  VK_INVALID = 0xfff
102  };
103 
104 private:
105  const MCExpr *Expr;
106  const VariantKind Kind;
107 
108  explicit AArch64MCExpr(const MCExpr *Expr, VariantKind Kind)
109  : Expr(Expr), Kind(Kind) {}
110 
111 public:
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 
133  return static_cast<VariantKind>(Kind & VK_SymLocBits);
134  }
135 
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:").
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
This represents an "assembler immediate".
Definition: MCValue.h:40
static const AArch64MCExpr * create(const MCExpr *Expr, VariantKind Kind, MCContext &Ctx)
ExprKind getKind() const
Definition: MCExpr.h:70
static bool classof(const AArch64MCExpr *)
Encode information on a single operation to perform on a byte sequence (e.g., an encoded instruction)...
Definition: MCFixup.h:66
StringRef getVariantKindName() const
Convert the variant kind into an ELF-appropriate modifier (e.g.
Encapsulates the layout of an assembly file at a particular point in time.
Definition: MCAsmLayout.h:29
Base class for the full range of assembler expressions which are needed for parsing.
Definition: MCExpr.h:34
This is an extension point for target-specific MCExpr subclasses to implement.
Definition: MCExpr.h:531
VariantKind getKind() const
Get the kind of this expression.
bool evaluateAsRelocatableImpl(MCValue &Res, const MCAsmLayout *Layout, const MCFixup *Fixup) const override
static VariantKind getAddressFrag(VariantKind Kind)
static GCRegistry::Add< CoreCLRGC > E("coreclr","CoreCLR-compatible GC")
This class is intended to be used as a base class for asm properties and features specific to the tar...
Definition: MCAsmInfo.h:57
Streaming machine code generation interface.
Definition: MCStreamer.h:161
void visitUsedExpr(MCStreamer &Streamer) const override
static bool isNotChecked(VariantKind Kind)
static bool classof(const MCExpr *E)
static VariantKind getSymbolLoc(VariantKind Kind)
void printImpl(raw_ostream &OS, const MCAsmInfo *MAI) const override
This class implements an extremely fast bulk output stream that can only output to a stream...
Definition: raw_ostream.h:44
void fixELFSymbolsInTLSFixups(MCAssembler &Asm) const override
StringRef - Represent a constant reference to a string, i.e.
Definition: StringRef.h:47
Target specific expression.
Definition: MCExpr.h:41
MCFragment * findAssociatedFragment() const override
const MCExpr * getSubExpr() const
Get the expression this modifier applies to.