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/TableGen/Error.h"
  18 #include "llvm/TableGen/Record.h"
  19 #include <map>
  20
  21 namespace llvm {
  22   class SourceMgr;
  23   class Twine;
  24   struct ForeachLoop;
  25   struct MultiClass;
  26   struct SubClassReference;
  27   struct SubMultiClassReference;
  28
  29   struct LetRecord {
  30     StringInit *Name;
  31     std::vector<unsigned> Bits;
  32     Init *Value;
  33     SMLoc Loc;
  34     LetRecord(StringInit *N, ArrayRef<unsigned> B, Init *V, SMLoc L)
  35       : Name(N), Bits(B), Value(V), Loc(L) {
  36     }
  37   };
  38
  39   /// RecordsEntry - Holds exactly one of a Record, ForeachLoop, or
  40   /// AssertionInfo.
  41   struct RecordsEntry {
  42     std::unique_ptr<Record> Rec;
  43     std::unique_ptr<ForeachLoop> Loop;
  44     std::unique_ptr<Record::AssertionInfo> Assertion;
  45
  46     void dump() const;
  47
  48     RecordsEntry() {}
  49     RecordsEntry(std::unique_ptr<Record> Rec) : Rec(std::move(Rec)) {}
  50     RecordsEntry(std::unique_ptr<ForeachLoop> Loop)
  51         : Loop(std::move(Loop)) {}
  52     RecordsEntry(std::unique_ptr<Record::AssertionInfo> Assertion)
  53         : Assertion(std::move(Assertion)) {}
  54   };
  55
  56   /// ForeachLoop - Record the iteration state associated with a for loop.
  57   /// This is used to instantiate items in the loop body.
  58   ///
  59   /// IterVar is allowed to be null, in which case no iteration variable is
  60   /// defined in the loop at all. (This happens when a ForeachLoop is
  61   /// constructed by desugaring an if statement.)
  62   struct ForeachLoop {
  63     SMLoc Loc;
  64     VarInit *IterVar;
  65     Init *ListValue;
  66     std::vector<RecordsEntry> Entries;
  67
  68     void dump() const;
  69
  70     ForeachLoop(SMLoc Loc, VarInit *IVar, Init *LValue)
  71       : Loc(Loc), IterVar(IVar), ListValue(LValue) {}
  72   };
  73
  74   struct DefsetRecord {
  75     SMLoc Loc;
  76     RecTy *EltTy = nullptr;
  77     SmallVector<Init *, 16> Elements;
  78   };
  79
  80 class TGLocalVarScope {
  81   // A scope to hold local variable definitions from defvar.
  82   std::map<std::string, Init *, std::less<>> vars;
  83   std::unique_ptr<TGLocalVarScope> parent;
  84
  85 public:
  86   TGLocalVarScope() = default;
  87   TGLocalVarScope(std::unique_ptr<TGLocalVarScope> parent)
  88       : parent(std::move(parent)) {}
  89
  90   std::unique_ptr<TGLocalVarScope> extractParent() {
  91     // This is expected to be called just before we are destructed, so
  92     // it doesn't much matter what state we leave 'parent' in.
  93     return std::move(parent);
  94   }
  95
  96   Init *getVar(StringRef Name) const {
  97     auto It = vars.find(Name);
  98     if (It != vars.end())
  99       return It->second;
 100     if (parent)
 101       return parent->getVar(Name);
 102     return nullptr;
 103   }
 104
 105   bool varAlreadyDefined(StringRef Name) const {
 106     // When we check whether a variable is already defined, for the purpose of
 107     // reporting an error on redefinition, we don't look up to the parent
 108     // scope, because it's all right to shadow an outer definition with an
 109     // inner one.
 110     return vars.find(Name) != vars.end();
 111   }
 112
 113   void addVar(StringRef Name, Init *I) {
 114     bool Ins = vars.insert(std::make_pair(std::string(Name), I)).second;
 115     (void)Ins;
 116     assert(Ins && "Local variable already exists");
 117   }
 118 };
 119
 120 struct MultiClass {
 121   Record Rec;  // Placeholder for template args and Name.
 122   std::vector<RecordsEntry> Entries;
 123
 124   void dump() const;
 125
 126   MultiClass(StringRef Name, SMLoc Loc, RecordKeeper &Records) :
 127     Rec(Name, Loc, Records) {}
 128 };
 129
 130 class TGParser {
 131   TGLexer Lex;
 132   std::vector<SmallVector<LetRecord, 4>> LetStack;
 133   std::map<std::string, std::unique_ptr<MultiClass>> MultiClasses;
 134
 135   /// Loops - Keep track of any foreach loops we are within.
 136   ///
 137   std::vector<std::unique_ptr<ForeachLoop>> Loops;
 138
 139   SmallVector<DefsetRecord *, 2> Defsets;
 140
 141   /// CurMultiClass - If we are parsing a 'multiclass' definition, this is the
 142   /// current value.
 143   MultiClass *CurMultiClass;
 144
 145   /// CurLocalScope - Innermost of the current nested scopes for 'defvar' local
 146   /// variables.
 147   std::unique_ptr<TGLocalVarScope> CurLocalScope;
 148
 149   // Record tracker
 150   RecordKeeper &Records;
 151
 152   // A "named boolean" indicating how to parse identifiers.  Usually
 153   // identifiers map to some existing object but in special cases
 154   // (e.g. parsing def names) no such object exists yet because we are
 155   // in the middle of creating in.  For those situations, allow the
 156   // parser to ignore missing object errors.
 157   enum IDParseMode {
 158     ParseValueMode,   // We are parsing a value we expect to look up.
 159     ParseNameMode,    // We are parsing a name of an object that does not yet
 160                       // exist.
 161   };
 162
 163   bool NoWarnOnUnusedTemplateArgs = false;
 164
 165 public:
 166   TGParser(SourceMgr &SM, ArrayRef<std::string> Macros, RecordKeeper &records,
 167            const bool NoWarnOnUnusedTemplateArgs = false)
 168       : Lex(SM, Macros), CurMultiClass(nullptr), Records(records),
 169         NoWarnOnUnusedTemplateArgs(NoWarnOnUnusedTemplateArgs) {}
 170
 171   /// ParseFile - Main entrypoint for parsing a tblgen file.  These parser
 172   /// routines return true on error, or false on success.
 173   bool ParseFile();
 174
 175   bool Error(SMLoc L, const Twine &Msg) const {
 176     PrintError(L, Msg);
 177     return true;
 178   }
 179   bool TokError(const Twine &Msg) const {
 180     return Error(Lex.getLoc(), Msg);
 181   }
 182   const TGLexer::DependenciesSetTy &getDependencies() const {
 183     return Lex.getDependencies();
 184   }
 185
 186   TGLocalVarScope *PushLocalScope() {
 187     CurLocalScope = std::make_unique<TGLocalVarScope>(std::move(CurLocalScope));
 188     // Returns a pointer to the new scope, so that the caller can pass it back
 189     // to PopLocalScope which will check by assertion that the pushes and pops
 190     // match up properly.
 191     return CurLocalScope.get();
 192   }
 193   void PopLocalScope(TGLocalVarScope *ExpectedStackTop) {
 194     assert(ExpectedStackTop == CurLocalScope.get() &&
 195            "Mismatched pushes and pops of local variable scopes");
 196     CurLocalScope = CurLocalScope->extractParent();
 197   }
 198
 199 private: // Semantic analysis methods.
 200   bool AddValue(Record *TheRec, SMLoc Loc, const RecordVal &RV);
 201   bool SetValue(Record *TheRec, SMLoc Loc, Init *ValName,
 202                 ArrayRef<unsigned> BitList, Init *V,
 203                 bool AllowSelfAssignment = false);
 204   bool AddSubClass(Record *Rec, SubClassReference &SubClass);
 205   bool AddSubClass(RecordsEntry &Entry, SubClassReference &SubClass);
 206   bool AddSubMultiClass(MultiClass *CurMC,
 207                         SubMultiClassReference &SubMultiClass);
 208
 209   using SubstStack = SmallVector<std::pair<Init *, Init *>, 8>;
 210
 211   bool addEntry(RecordsEntry E);
 212   bool resolve(const ForeachLoop &Loop, SubstStack &Stack, bool Final,
 213                std::vector<RecordsEntry> *Dest, SMLoc *Loc = nullptr);
 214   bool resolve(const std::vector<RecordsEntry> &Source, SubstStack &Substs,
 215                bool Final, std::vector<RecordsEntry> *Dest,
 216                SMLoc *Loc = nullptr);
 217   bool addDefOne(std::unique_ptr<Record> Rec);
 218
 219 private:  // Parser methods.
 220   bool consume(tgtok::TokKind K);
 221   bool ParseObjectList(MultiClass *MC = nullptr);
 222   bool ParseObject(MultiClass *MC);
 223   bool ParseClass();
 224   bool ParseMultiClass();
 225   bool ParseDefm(MultiClass *CurMultiClass);
 226   bool ParseDef(MultiClass *CurMultiClass);
 227   bool ParseDefset();
 228   bool ParseDefvar();
 229   bool ParseForeach(MultiClass *CurMultiClass);
 230   bool ParseIf(MultiClass *CurMultiClass);
 231   bool ParseIfBody(MultiClass *CurMultiClass, StringRef Kind);
 232   bool ParseAssert(MultiClass *CurMultiClass, Record *CurRec = nullptr);
 233   bool ParseTopLevelLet(MultiClass *CurMultiClass);
 234   void ParseLetList(SmallVectorImpl<LetRecord> &Result);
 235
 236   bool ParseObjectBody(Record *CurRec);
 237   bool ParseBody(Record *CurRec);
 238   bool ParseBodyItem(Record *CurRec);
 239
 240   bool ParseTemplateArgList(Record *CurRec);
 241   Init *ParseDeclaration(Record *CurRec, bool ParsingTemplateArgs);
 242   VarInit *ParseForeachDeclaration(Init *&ForeachListValue);
 243
 244   SubClassReference ParseSubClassReference(Record *CurRec, bool isDefm);
 245   SubMultiClassReference ParseSubMultiClassReference(MultiClass *CurMC);
 246
 247   Init *ParseIDValue(Record *CurRec, StringInit *Name, SMLoc NameLoc,
 248                      IDParseMode Mode = ParseValueMode);
 249   Init *ParseSimpleValue(Record *CurRec, RecTy *ItemType = nullptr,
 250                          IDParseMode Mode = ParseValueMode);
 251   Init *ParseValue(Record *CurRec, RecTy *ItemType = nullptr,
 252                    IDParseMode Mode = ParseValueMode);
 253   void ParseValueList(SmallVectorImpl<llvm::Init*> &Result,
 254                       Record *CurRec, RecTy *ItemType = nullptr);
 255   bool ParseTemplateArgValueList(SmallVectorImpl<llvm::Init *> &Result,
 256                                  Record *CurRec, Record *ArgsRec);
 257   void ParseDagArgList(
 258       SmallVectorImpl<std::pair<llvm::Init*, StringInit*>> &Result,
 259       Record *CurRec);
 260   bool ParseOptionalRangeList(SmallVectorImpl<unsigned> &Ranges);
 261   bool ParseOptionalBitList(SmallVectorImpl<unsigned> &Ranges);
 262   void ParseRangeList(SmallVectorImpl<unsigned> &Result);
 263   bool ParseRangePiece(SmallVectorImpl<unsigned> &Ranges,
 264                        TypedInit *FirstItem = nullptr);
 265   RecTy *ParseType();
 266   Init *ParseOperation(Record *CurRec, RecTy *ItemType);
 267   Init *ParseOperationSubstr(Record *CurRec, RecTy *ItemType);
 268   Init *ParseOperationFind(Record *CurRec, RecTy *ItemType);
 269   Init *ParseOperationForEachFilter(Record *CurRec, RecTy *ItemType);
 270   Init *ParseOperationCond(Record *CurRec, RecTy *ItemType);
 271   RecTy *ParseOperatorType();
 272   Init *ParseObjectName(MultiClass *CurMultiClass);
 273   Record *ParseClassID();
 274   MultiClass *ParseMultiClassID();
 275   bool ApplyLetStack(Record *CurRec);
 276   bool ApplyLetStack(RecordsEntry &Entry);
 277   bool CheckTemplateArgValues(SmallVectorImpl<llvm::Init *> &Values,
 278                               SMLoc Loc, Record *ArgsRec);
 279 };
 280
 281 } // end namespace llvm
 282
 283 #endif