1 //===-- llvm/MC/MCTargetAsmParser.h - Target Assembly Parser ----*- 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 #ifndef LLVM_MC_MCTARGETASMPARSER_H
11 #define LLVM_MC_MCTARGETASMPARSER_H
12 
13 #include "llvm/MC/MCExpr.h"
14 #include "llvm/MC/MCParser/MCAsmParserExtension.h"
15 #include "llvm/MC/MCTargetOptions.h"
16 #include <memory>
17 
18 namespace llvm {
19 class AsmToken;
20 class MCInst;
21 class MCParsedAsmOperand;
22 class MCStreamer;
23 class SMLoc;
24 class StringRef;
25 template <typename T> class SmallVectorImpl;
26 
27 typedef SmallVectorImpl<std::unique_ptr<MCParsedAsmOperand>> OperandVector;
28 
29 enum AsmRewriteKind {
30   AOK_Delete = 0,     // Rewrite should be ignored.
31   AOK_Align,          // Rewrite align as .align.
32   AOK_DotOperator,    // Rewrite a dot operator expression as an immediate.
33                       // E.g., [eax].foo.bar -> [eax].8
34   AOK_Emit,           // Rewrite _emit as .byte.
35   AOK_Imm,            // Rewrite as $$N.
36   AOK_ImmPrefix,      // Add $$ before a parsed Imm.
37   AOK_Input,          // Rewrite in terms of $N.
38   AOK_Output,         // Rewrite in terms of $N.
39   AOK_SizeDirective,  // Add a sizing directive (e.g., dword ptr).
40   AOK_Label,          // Rewrite local labels.
41   AOK_Skip            // Skip emission (e.g., offset/type operators).
42 };
43 
44 const char AsmRewritePrecedence [] = {
45   0, // AOK_Delete
46   2, // AOK_Align
47   2, // AOK_DotOperator
48   2, // AOK_Emit
49   4, // AOK_Imm
50   4, // AOK_ImmPrefix
51   3, // AOK_Input
52   3, // AOK_Output
53   5, // AOK_SizeDirective
54   1, // AOK_Label
55   2  // AOK_Skip
56 };
57 
58 struct AsmRewrite {
59   AsmRewriteKind Kind;
60   SMLoc Loc;
61   unsigned Len;
62   unsigned Val;
63   StringRef Label;
64 public:
65   AsmRewrite(AsmRewriteKind kind, SMLoc loc, unsigned len = 0, unsigned val = 0)
KindAsmRewrite66     : Kind(kind), Loc(loc), Len(len), Val(val) {}
AsmRewriteAsmRewrite67   AsmRewrite(AsmRewriteKind kind, SMLoc loc, unsigned len, StringRef label)
68     : Kind(kind), Loc(loc), Len(len), Val(0), Label(label) {}
69 };
70 
71 struct ParseInstructionInfo {
72 
73   SmallVectorImpl<AsmRewrite> *AsmRewrites;
74 
ParseInstructionInfoParseInstructionInfo75   ParseInstructionInfo() : AsmRewrites(nullptr) {}
ParseInstructionInfoParseInstructionInfo76   ParseInstructionInfo(SmallVectorImpl<AsmRewrite> *rewrites)
77     : AsmRewrites(rewrites) {}
78 };
79 
80 /// MCTargetAsmParser - Generic interface to target specific assembly parsers.
81 class MCTargetAsmParser : public MCAsmParserExtension {
82 public:
83   enum MatchResultTy {
84     Match_InvalidOperand,
85     Match_MissingFeature,
86     Match_MnemonicFail,
87     Match_Success,
88     FIRST_TARGET_MATCH_RESULT_TY
89   };
90 
91 private:
92   MCTargetAsmParser(const MCTargetAsmParser &) = delete;
93   void operator=(const MCTargetAsmParser &) = delete;
94 protected: // Can only create subclasses.
95   MCTargetAsmParser();
96 
97   /// AvailableFeatures - The current set of available features.
98   uint64_t AvailableFeatures;
99 
100   /// ParsingInlineAsm - Are we parsing ms-style inline assembly?
101   bool ParsingInlineAsm;
102 
103   /// SemaCallback - The Sema callback implementation.  Must be set when parsing
104   /// ms-style inline assembly.
105   MCAsmParserSemaCallback *SemaCallback;
106 
107   /// Set of options which affects instrumentation of inline assembly.
108   MCTargetOptions MCOptions;
109 
110 public:
111   ~MCTargetAsmParser() override;
112 
getAvailableFeatures()113   uint64_t getAvailableFeatures() const { return AvailableFeatures; }
setAvailableFeatures(uint64_t Value)114   void setAvailableFeatures(uint64_t Value) { AvailableFeatures = Value; }
115 
isParsingInlineAsm()116   bool isParsingInlineAsm () { return ParsingInlineAsm; }
setParsingInlineAsm(bool Value)117   void setParsingInlineAsm (bool Value) { ParsingInlineAsm = Value; }
118 
getTargetOptions()119   MCTargetOptions getTargetOptions() const { return MCOptions; }
120 
setSemaCallback(MCAsmParserSemaCallback * Callback)121   void setSemaCallback(MCAsmParserSemaCallback *Callback) {
122     SemaCallback = Callback;
123   }
124 
125   virtual bool ParseRegister(unsigned &RegNo, SMLoc &StartLoc,
126                              SMLoc &EndLoc) = 0;
127 
128   /// Sets frame register corresponding to the current MachineFunction.
SetFrameRegister(unsigned RegNo)129   virtual void SetFrameRegister(unsigned RegNo) {}
130 
131   /// ParseInstruction - Parse one assembly instruction.
132   ///
133   /// The parser is positioned following the instruction name. The target
134   /// specific instruction parser should parse the entire instruction and
135   /// construct the appropriate MCInst, or emit an error. On success, the entire
136   /// line should be parsed up to and including the end-of-statement token. On
137   /// failure, the parser is not required to read to the end of the line.
138   //
139   /// \param Name - The instruction name.
140   /// \param NameLoc - The source location of the name.
141   /// \param Operands [out] - The list of parsed operands, this returns
142   ///        ownership of them to the caller.
143   /// \return True on failure.
144   virtual bool ParseInstruction(ParseInstructionInfo &Info, StringRef Name,
145                                 SMLoc NameLoc, OperandVector &Operands) = 0;
146 
147   /// ParseDirective - Parse a target specific assembler directive
148   ///
149   /// The parser is positioned following the directive name.  The target
150   /// specific directive parser should parse the entire directive doing or
151   /// recording any target specific work, or return true and do nothing if the
152   /// directive is not target specific. If the directive is specific for
153   /// the target, the entire line is parsed up to and including the
154   /// end-of-statement token and false is returned.
155   ///
156   /// \param DirectiveID - the identifier token of the directive.
157   virtual bool ParseDirective(AsmToken DirectiveID) = 0;
158 
159   /// mnemonicIsValid - This returns true if this is a valid mnemonic and false
160   /// otherwise.
161   virtual bool mnemonicIsValid(StringRef Mnemonic, unsigned VariantID) = 0;
162 
163   /// MatchAndEmitInstruction - Recognize a series of operands of a parsed
164   /// instruction as an actual MCInst and emit it to the specified MCStreamer.
165   /// This returns false on success and returns true on failure to match.
166   ///
167   /// On failure, the target parser is responsible for emitting a diagnostic
168   /// explaining the match failure.
169   virtual bool MatchAndEmitInstruction(SMLoc IDLoc, unsigned &Opcode,
170                                        OperandVector &Operands, MCStreamer &Out,
171                                        uint64_t &ErrorInfo,
172                                        bool MatchingInlineAsm) = 0;
173 
174   /// Allows targets to let registers opt out of clobber lists.
OmitRegisterFromClobberLists(unsigned RegNo)175   virtual bool OmitRegisterFromClobberLists(unsigned RegNo) { return false; }
176 
177   /// Allow a target to add special case operand matching for things that
178   /// tblgen doesn't/can't handle effectively. For example, literal
179   /// immediates on ARM. TableGen expects a token operand, but the parser
180   /// will recognize them as immediates.
validateTargetOperandClass(MCParsedAsmOperand & Op,unsigned Kind)181   virtual unsigned validateTargetOperandClass(MCParsedAsmOperand &Op,
182                                               unsigned Kind) {
183     return Match_InvalidOperand;
184   }
185 
186   /// checkTargetMatchPredicate - Validate the instruction match against
187   /// any complex target predicates not expressible via match classes.
checkTargetMatchPredicate(MCInst & Inst)188   virtual unsigned checkTargetMatchPredicate(MCInst &Inst) {
189     return Match_Success;
190   }
191 
192   virtual void convertToMapAndConstraints(unsigned Kind,
193                                           const OperandVector &Operands) = 0;
194 
applyModifierToExpr(const MCExpr * E,MCSymbolRefExpr::VariantKind,MCContext & Ctx)195   virtual const MCExpr *applyModifierToExpr(const MCExpr *E,
196                                             MCSymbolRefExpr::VariantKind,
197                                             MCContext &Ctx) {
198     return nullptr;
199   }
200 
onLabelParsed(MCSymbol * Symbol)201   virtual void onLabelParsed(MCSymbol *Symbol) { };
202 };
203 
204 } // End llvm namespace
205 
206 #endif
207