1 //===- MCInstPrinter.h - MCInst to target assembly syntax -------*- 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 #ifndef LLVM_MC_MCINSTPRINTER_H
10 #define LLVM_MC_MCINSTPRINTER_H
11 
12 #include "llvm/Support/Format.h"
13 #include <cstdint>
14 
15 namespace llvm {
16 
17 class MCAsmInfo;
18 class MCInst;
19 class MCOperand;
20 class MCInstrInfo;
21 class MCInstrAnalysis;
22 class MCRegisterInfo;
23 class MCSubtargetInfo;
24 class raw_ostream;
25 class StringRef;
26 
27 /// Convert `Bytes' to a hex string and output to `OS'
28 void dumpBytes(ArrayRef<uint8_t> Bytes, raw_ostream &OS);
29 
30 namespace HexStyle {
31 
32 enum Style {
33   C,  ///< 0xff
34   Asm ///< 0ffh
35 };
36 
37 } // end namespace HexStyle
38 
39 struct AliasMatchingData;
40 
41 /// This is an instance of a target assembly language printer that
42 /// converts an MCInst to valid target assembly syntax.
43 class MCInstPrinter {
44 protected:
45   /// A stream that comments can be emitted to if desired.  Each comment
46   /// must end with a newline.  This will be null if verbose assembly emission
47   /// is disabled.
48   raw_ostream *CommentStream = nullptr;
49   const MCAsmInfo &MAI;
50   const MCInstrInfo &MII;
51   const MCRegisterInfo &MRI;
52   const MCInstrAnalysis *MIA = nullptr;
53 
54   /// True if we are printing marked up assembly.
55   bool UseMarkup = false;
56 
57   /// True if we prefer aliases (e.g. nop) to raw mnemonics.
58   bool PrintAliases = true;
59 
60   /// True if we are printing immediates as hex.
61   bool PrintImmHex = false;
62 
63   /// Which style to use for printing hexadecimal values.
64   HexStyle::Style PrintHexStyle = HexStyle::C;
65 
66   /// If true, a branch immediate (e.g. bl 4) will be printed as a hexadecimal
67   /// address (e.g. bl 0x20004). This is useful for a stream disassembler
68   /// (llvm-objdump -d).
69   bool PrintBranchImmAsAddress = false;
70 
71   /// If true, symbolize branch target and memory reference operands.
72   bool SymbolizeOperands = false;
73 
74   /// Utility function for printing annotations.
75   void printAnnotation(raw_ostream &OS, StringRef Annot);
76 
77   /// Helper for matching MCInsts to alias patterns when printing instructions.
78   const char *matchAliasPatterns(const MCInst *MI, const MCSubtargetInfo *STI,
79                                  const AliasMatchingData &M);
80 
81 public:
MCInstPrinter(const MCAsmInfo & mai,const MCInstrInfo & mii,const MCRegisterInfo & mri)82   MCInstPrinter(const MCAsmInfo &mai, const MCInstrInfo &mii,
83                 const MCRegisterInfo &mri) : MAI(mai), MII(mii), MRI(mri) {}
84 
85   virtual ~MCInstPrinter();
86 
87   /// Customize the printer according to a command line option.
88   /// @return true if the option is recognized and applied.
applyTargetSpecificCLOption(StringRef Opt)89   virtual bool applyTargetSpecificCLOption(StringRef Opt) { return false; }
90 
91   /// Specify a stream to emit comments to.
setCommentStream(raw_ostream & OS)92   void setCommentStream(raw_ostream &OS) { CommentStream = &OS; }
93 
94   /// Returns a pair containing the mnemonic for \p MI and the number of bits
95   /// left for further processing by printInstruction (generated by tablegen).
96   virtual std::pair<const char *, uint64_t> getMnemonic(const MCInst *MI) = 0;
97 
98   /// Print the specified MCInst to the specified raw_ostream.
99   ///
100   /// \p Address the address of current instruction on most targets, used to
101   /// print a PC relative immediate as the target address. On targets where a PC
102   /// relative immediate is relative to the next instruction and the length of a
103   /// MCInst is difficult to measure (e.g. x86), this is the address of the next
104   /// instruction. If Address is 0, the immediate will be printed.
105   virtual void printInst(const MCInst *MI, uint64_t Address, StringRef Annot,
106                          const MCSubtargetInfo &STI, raw_ostream &OS) = 0;
107 
108   /// Return the name of the specified opcode enum (e.g. "MOV32ri") or
109   /// empty if we can't resolve it.
110   StringRef getOpcodeName(unsigned Opcode) const;
111 
112   /// Print the assembler register name.
113   virtual void printRegName(raw_ostream &OS, unsigned RegNo) const;
114 
getUseMarkup()115   bool getUseMarkup() const { return UseMarkup; }
setUseMarkup(bool Value)116   void setUseMarkup(bool Value) { UseMarkup = Value; }
117 
118   /// Utility functions to make adding mark ups simpler.
119   StringRef markup(StringRef s) const;
120 
getPrintImmHex()121   bool getPrintImmHex() const { return PrintImmHex; }
setPrintImmHex(bool Value)122   void setPrintImmHex(bool Value) { PrintImmHex = Value; }
123 
setPrintHexStyle(HexStyle::Style Value)124   void setPrintHexStyle(HexStyle::Style Value) { PrintHexStyle = Value; }
125 
setPrintBranchImmAsAddress(bool Value)126   void setPrintBranchImmAsAddress(bool Value) {
127     PrintBranchImmAsAddress = Value;
128   }
129 
setSymbolizeOperands(bool Value)130   void setSymbolizeOperands(bool Value) { SymbolizeOperands = Value; }
setMCInstrAnalysis(const MCInstrAnalysis * Value)131   void setMCInstrAnalysis(const MCInstrAnalysis *Value) { MIA = Value; }
132 
133   /// Utility function to print immediates in decimal or hex.
formatImm(int64_t Value)134   format_object<int64_t> formatImm(int64_t Value) const {
135     return PrintImmHex ? formatHex(Value) : formatDec(Value);
136   }
137 
138   /// Utility functions to print decimal/hexadecimal values.
139   format_object<int64_t> formatDec(int64_t Value) const;
140   format_object<int64_t> formatHex(int64_t Value) const;
141   format_object<uint64_t> formatHex(uint64_t Value) const;
142 };
143 
144 /// Map from opcode to pattern list by binary search.
145 struct PatternsForOpcode {
146   uint32_t Opcode;
147   uint16_t PatternStart;
148   uint16_t NumPatterns;
149 };
150 
151 /// Data for each alias pattern. Includes feature bits, string, number of
152 /// operands, and a variadic list of conditions to check.
153 struct AliasPattern {
154   uint32_t AsmStrOffset;
155   uint32_t AliasCondStart;
156   uint8_t NumOperands;
157   uint8_t NumConds;
158 };
159 
160 struct AliasPatternCond {
161   enum CondKind : uint8_t {
162     K_Feature,       // Match only if a feature is enabled.
163     K_NegFeature,    // Match only if a feature is disabled.
164     K_OrFeature,     // Match only if one of a set of features is enabled.
165     K_OrNegFeature,  // Match only if one of a set of features is disabled.
166     K_EndOrFeatures, // Note end of list of K_Or(Neg)?Features.
167     K_Ignore,        // Match any operand.
168     K_Reg,           // Match a specific register.
169     K_TiedReg,       // Match another already matched register.
170     K_Imm,           // Match a specific immediate.
171     K_RegClass,      // Match registers in a class.
172     K_Custom,        // Call custom matcher by index.
173   };
174 
175   CondKind Kind;
176   uint32_t Value;
177 };
178 
179 /// Tablegenerated data structures needed to match alias patterns.
180 struct AliasMatchingData {
181   ArrayRef<PatternsForOpcode> OpToPatterns;
182   ArrayRef<AliasPattern> Patterns;
183   ArrayRef<AliasPatternCond> PatternConds;
184   StringRef AsmStrings;
185   bool (*ValidateMCOperand)(const MCOperand &MCOp, const MCSubtargetInfo &STI,
186                             unsigned PredicateIndex);
187 };
188 
189 } // end namespace llvm
190 
191 #endif // LLVM_MC_MCINSTPRINTER_H
192