llvm/lib/TableGen/TGParser.h

   1 //===- TGParser.h - Parser for TableGen Files -------------------*- 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 // This class represents the Parser for tablegen files.
  10 //
  11 //===----------------------------------------------------------------------===//
  12
  13 #ifndef LLVM_LIB_TABLEGEN_TGPARSER_H
  14 #define LLVM_LIB_TABLEGEN_TGPARSER_H
  15
  16 #include "TGLexer.h"
  17 #include "llvm/ADT/Twine.h"
  18 #include "llvm/Support/SourceMgr.h"
  19 #include "llvm/TableGen/Error.h"
  20 #include "llvm/TableGen/Record.h"
  21 #include <map>
  22
  23 namespace llvm {
  24   class Record;
  25   class RecordVal;
  26   class RecordKeeper;
  27   class RecTy;
  28   class Init;
  29   struct ForeachLoop;
  30   struct MultiClass;
  31   struct SubClassReference;
  32   struct SubMultiClassReference;
  33
  34   struct LetRecord {
  35     StringInit *Name;
  36     std::vector<unsigned> Bits;
  37     Init *Value;
  38     SMLoc Loc;
  39     LetRecord(StringInit *N, ArrayRef<unsigned> B, Init *V, SMLoc L)
  40       : Name(N), Bits(B), Value(V), Loc(L) {
  41     }
  42   };
  43
  44   /// RecordsEntry - Can be either a record or a foreach loop.
  45   struct RecordsEntry {
  46     std::unique_ptr<Record> Rec;
  47     std::unique_ptr<ForeachLoop> Loop;
  48
  49     void dump() const;
  50
  51     RecordsEntry() {}
  52     RecordsEntry(std::unique_ptr<Record> Rec) : Rec(std::move(Rec)) {}
  53     RecordsEntry(std::unique_ptr<ForeachLoop> Loop)
  54       : Loop(std::move(Loop)) {}
  55   };
  56
  57   /// ForeachLoop - Record the iteration state associated with a for loop.
  58   /// This is used to instantiate items in the loop body.
  59   ///
  60   /// IterVar is allowed to be null, in which case no iteration variable is
  61   /// defined in the loop at all. (This happens when a ForeachLoop is
  62   /// constructed by desugaring an if statement.)
  63   struct ForeachLoop {
  64     SMLoc Loc;
  65     VarInit *IterVar;
  66     Init *ListValue;
  67     std::vector<RecordsEntry> Entries;
  68
  69     void dump() const;
  70
  71     ForeachLoop(SMLoc Loc, VarInit *IVar, Init *LValue)
  72       : Loc(Loc), IterVar(IVar), ListValue(LValue) {}
  73   };
  74
  75   struct DefsetRecord {
  76     SMLoc Loc;
  77     RecTy *EltTy = nullptr;
  78     SmallVector<Init *, 16> Elements;
  79   };
  80
  81 class TGLocalVarScope {
  82   // A scope to hold local variable definitions from defvar.
  83   std::map<std::string, Init *, std::less<>> vars;
  84   std::unique_ptr<TGLocalVarScope> parent;
  85
  86 public:
  87   TGLocalVarScope() = default;
  88   TGLocalVarScope(std::unique_ptr<TGLocalVarScope> parent)
  89       : parent(std::move(parent)) {}
  90
  91   std::unique_ptr<TGLocalVarScope> extractParent() {
  92     // This is expected to be called just before we are destructed, so
  93     // it doesn't much matter what state we leave 'parent' in.
  94     return std::move(parent);
  95   }
  96
  97   Init *getVar(StringRef Name) const {
  98     auto It = vars.find(Name);
  99     if (It != vars.end())
 100       return It->second;
 101     if (parent)
 102       return parent->getVar(Name);
 103     return nullptr;
 104   }
 105
 106   bool varAlreadyDefined(StringRef Name) const {
 107     // When we check whether a variable is already defined, for the purpose of
 108     // reporting an error on redefinition, we don't look up to the parent
 109     // scope, because it's all right to shadow an outer definition with an
 110     // inner one.
 111     return vars.find(Name) != vars.end();
 112   }
 113
 114   void addVar(StringRef Name, Init *I) {
 115     bool Ins = vars.insert(std::make_pair(Name, I)).second;
 116     (void)Ins;
 117     assert(Ins && "Local variable already exists");
 118   }
 119 };
 120
 121 struct MultiClass {
 122   Record Rec;  // Placeholder for template args and Name.
 123   std::vector<RecordsEntry> Entries;
 124
 125   void dump() const;
 126
 127   MultiClass(StringRef Name, SMLoc Loc, RecordKeeper &Records) :
 128     Rec(Name, Loc, Records) {}
 129 };
 130
 131 class TGParser {
 132   TGLexer Lex;
 133   std::vector<SmallVector<LetRecord, 4>> LetStack;
 134   std::map<std::string, std::unique_ptr<MultiClass>> MultiClasses;
 135
 136   /// Loops - Keep track of any foreach loops we are within.
 137   ///
 138   std::vector<std::unique_ptr<ForeachLoop>> Loops;
 139
 140   SmallVector<DefsetRecord *, 2> Defsets;
 141
 142   /// CurMultiClass - If we are parsing a 'multiclass' definition, this is the
 143   /// current value.
 144   MultiClass *CurMultiClass;
 145
 146   /// CurLocalScope - Innermost of the current nested scopes for 'defvar' local
 147   /// variables.
 148   std::unique_ptr<TGLocalVarScope> CurLocalScope;
 149
 150   // Record tracker
 151   RecordKeeper &Records;
 152
 153   // A "named boolean" indicating how to parse identifiers.  Usually
 154   // identifiers map to some existing object but in special cases
 155   // (e.g. parsing def names) no such object exists yet because we are
 156   // in the middle of creating in.  For those situations, allow the
 157   // parser to ignore missing object errors.
 158   enum IDParseMode {
 159     ParseValueMode,   // We are parsing a value we expect to look up.
 160     ParseNameMode,    // We are parsing a name of an object that does not yet
 161                       // exist.
 162   };
 163
 164 public:
 165   TGParser(SourceMgr &SM, ArrayRef<std::string> Macros,
 166            RecordKeeper &records)
 167     : Lex(SM, Macros), CurMultiClass(nullptr), Records(records) {}
 168
 169   /// ParseFile - Main entrypoint for parsing a tblgen file.  These parser
 170   /// routines return true on error, or false on success.
 171   bool ParseFile();
 172
 173   bool Error(SMLoc L, const Twine &Msg) const {
 174     PrintError(L, Msg);
 175     return true;
 176   }
 177   bool TokError(const Twine &Msg) const {
 178     return Error(Lex.getLoc(), Msg);
 179   }
 180   const TGLexer::DependenciesSetTy &getDependencies() const {
 181     return Lex.getDependencies();
 182   }
 183
 184   TGLocalVarScope *PushLocalScope() {
 185     CurLocalScope = std::make_unique<TGLocalVarScope>(std::move(CurLocalScope));
 186     // Returns a pointer to the new scope, so that the caller can pass it back
 187     // to PopLocalScope which will check by assertion that the pushes and pops
 188     // match up properly.
 189     return CurLocalScope.get();
 190   }
 191   void PopLocalScope(TGLocalVarScope *ExpectedStackTop) {
 192     assert(ExpectedStackTop == CurLocalScope.get() &&
 193            "Mismatched pushes and pops of local variable scopes");
 194     CurLocalScope = CurLocalScope->extractParent();
 195   }
 196
 197 private: // Semantic analysis methods.
 198   bool AddValue(Record *TheRec, SMLoc Loc, const RecordVal &RV);
 199   bool SetValue(Record *TheRec, SMLoc Loc, Init *ValName,
 200                 ArrayRef<unsigned> BitList, Init *V,
 201                 bool AllowSelfAssignment = false);
 202   bool AddSubClass(Record *Rec, SubClassReference &SubClass);
 203   bool AddSubClass(RecordsEntry &Entry, SubClassReference &SubClass);
 204   bool AddSubMultiClass(MultiClass *CurMC,
 205                         SubMultiClassReference &SubMultiClass);
 206
 207   using SubstStack = SmallVector<std::pair<Init *, Init *>, 8>;
 208
 209   bool addEntry(RecordsEntry E);
 210   bool resolve(const ForeachLoop &Loop, SubstStack &Stack, bool Final,
 211                std::vector<RecordsEntry> *Dest, SMLoc *Loc = nullptr);
 212   bool resolve(const std::vector<RecordsEntry> &Source, SubstStack &Substs,
 213                bool Final, std::vector<RecordsEntry> *Dest,
 214                SMLoc *Loc = nullptr);
 215   bool addDefOne(std::unique_ptr<Record> Rec);
 216
 217 private:  // Parser methods.
 218   bool ParseObjectList(MultiClass *MC = nullptr);
 219   bool ParseObject(MultiClass *MC);
 220   bool ParseClass();
 221   bool ParseMultiClass();
 222   bool ParseDefm(MultiClass *CurMultiClass);
 223   bool ParseDef(MultiClass *CurMultiClass);
 224   bool ParseDefset();
 225   bool ParseDefvar();
 226   bool ParseForeach(MultiClass *CurMultiClass);
 227   bool ParseIf(MultiClass *CurMultiClass);
 228   bool ParseIfBody(MultiClass *CurMultiClass, StringRef Kind);
 229   bool ParseTopLevelLet(MultiClass *CurMultiClass);
 230   void ParseLetList(SmallVectorImpl<LetRecord> &Result);
 231
 232   bool ParseObjectBody(Record *CurRec);
 233   bool ParseBody(Record *CurRec);
 234   bool ParseBodyItem(Record *CurRec);
 235
 236   bool ParseTemplateArgList(Record *CurRec);
 237   Init *ParseDeclaration(Record *CurRec, bool ParsingTemplateArgs);
 238   VarInit *ParseForeachDeclaration(Init *&ForeachListValue);
 239
 240   SubClassReference ParseSubClassReference(Record *CurRec, bool isDefm);
 241   SubMultiClassReference ParseSubMultiClassReference(MultiClass *CurMC);
 242
 243   Init *ParseIDValue(Record *CurRec, StringInit *Name, SMLoc NameLoc,
 244                      IDParseMode Mode = ParseValueMode);
 245   Init *ParseSimpleValue(Record *CurRec, RecTy *ItemType = nullptr,
 246                          IDParseMode Mode = ParseValueMode);
 247   Init *ParseValue(Record *CurRec, RecTy *ItemType = nullptr,
 248                    IDParseMode Mode = ParseValueMode);
 249   void ParseValueList(SmallVectorImpl<llvm::Init*> &Result, Record *CurRec,
 250                       Record *ArgsRec = nullptr, RecTy *EltTy = nullptr);
 251   void ParseDagArgList(
 252       SmallVectorImpl<std::pair<llvm::Init*, StringInit*>> &Result,
 253       Record *CurRec);
 254   bool ParseOptionalRangeList(SmallVectorImpl<unsigned> &Ranges);
 255   bool ParseOptionalBitList(SmallVectorImpl<unsigned> &Ranges);
 256   void ParseRangeList(SmallVectorImpl<unsigned> &Result);
 257   bool ParseRangePiece(SmallVectorImpl<unsigned> &Ranges,
 258                        TypedInit *FirstItem = nullptr);
 259   RecTy *ParseType();
 260   Init *ParseOperation(Record *CurRec, RecTy *ItemType);
 261   Init *ParseOperationCond(Record *CurRec, RecTy *ItemType);
 262   RecTy *ParseOperatorType();
 263   Init *ParseObjectName(MultiClass *CurMultiClass);
 264   Record *ParseClassID();
 265   MultiClass *ParseMultiClassID();
 266   bool ApplyLetStack(Record *CurRec);
 267   bool ApplyLetStack(RecordsEntry &Entry);
 268 };
 269
 270 } // end namespace llvm
 271
 272 #endif