LLVM  8.0.0svn
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_SECREL = 0x008,
39  VK_SymLocBits = 0x00f,
40 
41  // Variants specifying which part of the final address calculation is
42  // used. E.g. the low 12 bits for an ADD/LDR, the middle 16 bits for a
43  // MOVZ/MOVK.
44  VK_PAGE = 0x010,
45  VK_PAGEOFF = 0x020,
46  VK_HI12 = 0x030,
47  VK_G0 = 0x040,
48  VK_G1 = 0x050,
49  VK_G2 = 0x060,
50  VK_G3 = 0x070,
52 
53  // Whether the final relocation is a checked one (where a linker should
54  // perform a range-check on the final address) or not. Note that this field
55  // is unfortunately sometimes omitted from the assembly syntax. E.g. :lo12:
56  // on its own is a non-checked relocation. We side with ELF on being
57  // explicit about this!
58  VK_NC = 0x100,
59 
60  // Convenience definitions for referring to specific textual representations
61  // of relocation specifiers. Note that this means the "_NC" is sometimes
62  // omitted in line with assembly syntax here (VK_LO12 rather than VK_LO12_NC
63  // since a user would write ":lo12:").
104 
105  VK_INVALID = 0xfff
106  };
107 
108 private:
109  const MCExpr *Expr;
110  const VariantKind Kind;
111 
112  explicit AArch64MCExpr(const MCExpr *Expr, VariantKind Kind)
113  : Expr(Expr), Kind(Kind) {}
114 
115 public:
116  /// @name Construction
117  /// @{
118 
119  static const AArch64MCExpr *create(const MCExpr *Expr, VariantKind Kind,
120  MCContext &Ctx);
121 
122  /// @}
123  /// @name Accessors
124  /// @{
125 
126  /// Get the kind of this expression.
127  VariantKind getKind() const { return Kind; }
128 
129  /// Get the expression this modifier applies to.
130  const MCExpr *getSubExpr() const { return Expr; }
131 
132  /// @}
133  /// @name VariantKind information extractors.
134  /// @{
135 
137  return static_cast<VariantKind>(Kind & VK_SymLocBits);
138  }
139 
141  return static_cast<VariantKind>(Kind & VK_AddressFragBits);
142  }
143 
144  static bool isNotChecked(VariantKind Kind) { return Kind & VK_NC; }
145 
146  /// @}
147 
148  /// Convert the variant kind into an ELF-appropriate modifier
149  /// (e.g. ":got:", ":lo12:").
151 
152  void printImpl(raw_ostream &OS, const MCAsmInfo *MAI) const override;
153 
154  void visitUsedExpr(MCStreamer &Streamer) const override;
155 
156  MCFragment *findAssociatedFragment() const override;
157 
158  bool evaluateAsRelocatableImpl(MCValue &Res, const MCAsmLayout *Layout,
159  const MCFixup *Fixup) const override;
160 
161  void fixELFSymbolsInTLSFixups(MCAssembler &Asm) const override;
162 
163  static bool classof(const MCExpr *E) {
164  return E->getKind() == MCExpr::Target;
165  }
166 
167  static bool classof(const AArch64MCExpr *) { return true; }
168 };
169 } // end namespace llvm
170 
171 #endif
VariantKind getKind() const
Get the kind of this expression.
This class represents lattice values for constants.
Definition: AllocatorList.h:24
This represents an "assembler immediate".
Definition: MCValue.h:40
static const AArch64MCExpr * create(const MCExpr *Expr, VariantKind Kind, MCContext &Ctx)
static bool classof(const AArch64MCExpr *)
StringRef getVariantKindName() const
Convert the variant kind into an ELF-appropriate modifier (e.g.
Encode information on a single operation to perform on a byte sequence (e.g., an encoded instruction)...
Definition: MCFixup.h:74
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:36
This is an extension point for target-specific MCExpr subclasses to implement.
Definition: MCExpr.h:581
bool evaluateAsRelocatableImpl(MCValue &Res, const MCAsmLayout *Layout, const MCFixup *Fixup) const override
Context object for machine code objects.
Definition: MCContext.h:63
static VariantKind getAddressFrag(VariantKind Kind)
This class is intended to be used as a base class for asm properties and features specific to the tar...
Definition: MCAsmInfo.h:56
Streaming machine code generation interface.
Definition: MCStreamer.h:189
const MCExpr * getSubExpr() const
Get the expression this modifier applies to.
static GCRegistry::Add< CoreCLRGC > E("coreclr", "CoreCLR-compatible GC")
void visitUsedExpr(MCStreamer &Streamer) const override
PowerPC TLS Dynamic Call Fixup
ExprKind getKind() const
Definition: MCExpr.h:73
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:46
void fixELFSymbolsInTLSFixups(MCAssembler &Asm) const override
StringRef - Represent a constant reference to a string, i.e.
Definition: StringRef.h:49
Target specific expression.
Definition: MCExpr.h:43
MCFragment * findAssociatedFragment() const override