using System.Collections.Generic; using System.Numerics; using Microsoft.Boogie; using System.IO; using System.Text; using System; using System.Diagnostics.Contracts; namespace Microsoft.Dafny { public class Parser { public const int _EOF = 0; public const int _ident = 1; public const int _digits = 2; public const int _hexdigits = 3; public const int _decimaldigits = 4; public const int _arrayToken = 5; public const int _string = 6; public const int _colon = 7; public const int _semi = 8; public const int _lbrace = 9; public const int _rbrace = 10; public const int _openparen = 11; public const int _closeparen = 12; public const int _star = 13; public const int _notIn = 14; public const int maxT = 126; const bool T = true; const bool x = false; const int minErrDist = 2; public Scanner/*!*/ scanner; public Errors/*!*/ errors; public Token/*!*/ t; // last recognized token public Token/*!*/ la; // lookahead token int errDist = minErrDist; readonly Expression/*!*/ dummyExpr; readonly AssignmentRhs/*!*/ dummyRhs; readonly FrameExpression/*!*/ dummyFrameExpr; readonly Statement/*!*/ dummyStmt; readonly Attributes.Argument/*!*/ dummyAttrArg; readonly ModuleDecl theModule; readonly BuiltIns theBuiltIns; readonly bool theVerifyThisFile; int anonymousIds = 0; struct MemberModifiers { public bool IsGhost; public bool IsStatic; } /// /// Parses top-level things (modules, classes, datatypes, class members) from "filename" /// and appends them in appropriate form to "module". /// Returns the number of parsing errors encountered. /// Note: first initialize the Scanner. /// public static int Parse (string/*!*/ filename, ModuleDecl module, BuiltIns builtIns, Errors/*!*/ errors, bool verifyThisFile=true) /* throws System.IO.IOException */ { Contract.Requires(filename != null); Contract.Requires(module != null); string s; if (filename == "stdin.dfy") { s = Microsoft.Boogie.ParserHelper.Fill(System.Console.In, new List()); return Parse(s, filename, module, builtIns, errors, verifyThisFile); } else { using (System.IO.StreamReader reader = new System.IO.StreamReader(filename)) { s = Microsoft.Boogie.ParserHelper.Fill(reader, new List()); return Parse(s, DafnyOptions.Clo.UseBaseNameForFileName ? Path.GetFileName(filename) : filename, module, builtIns, errors, verifyThisFile); } } } /// /// Parses top-level things (modules, classes, datatypes, class members) /// and appends them in appropriate form to "module". /// Returns the number of parsing errors encountered. /// Note: first initialize the Scanner. /// public static int Parse (string/*!*/ s, string/*!*/ filename, ModuleDecl module, BuiltIns builtIns, bool verifyThisFile=true) { Contract.Requires(s != null); Contract.Requires(filename != null); Contract.Requires(module != null); Errors errors = new Errors(); return Parse(s, filename, module, builtIns, errors, verifyThisFile); } /// /// Parses top-level things (modules, classes, datatypes, class members) /// and appends them in appropriate form to "module". /// Returns the number of parsing errors encountered. /// Note: first initialize the Scanner with the given Errors sink. /// public static int Parse (string/*!*/ s, string/*!*/ filename, ModuleDecl module, BuiltIns builtIns, Errors/*!*/ errors, bool verifyThisFile=true) { Contract.Requires(s != null); Contract.Requires(filename != null); Contract.Requires(module != null); Contract.Requires(errors != null); byte[]/*!*/ buffer = cce.NonNull( UTF8Encoding.Default.GetBytes(s)); MemoryStream ms = new MemoryStream(buffer,false); Scanner scanner = new Scanner(ms, errors, filename); Parser parser = new Parser(scanner, errors, module, builtIns, verifyThisFile); parser.Parse(); return parser.errors.count; } public Parser(Scanner/*!*/ scanner, Errors/*!*/ errors, ModuleDecl module, BuiltIns builtIns, bool verifyThisFile=true) : this(scanner, errors) // the real work { // initialize readonly fields dummyExpr = new LiteralExpr(Token.NoToken); dummyRhs = new ExprRhs(dummyExpr, null); dummyFrameExpr = new FrameExpression(dummyExpr.tok, dummyExpr, null); dummyStmt = new ReturnStmt(Token.NoToken, Token.NoToken, null); dummyAttrArg = new Attributes.Argument(Token.NoToken, "dummyAttrArg"); theModule = module; theBuiltIns = builtIns; theVerifyThisFile = verifyThisFile; } bool IsAttribute() { Token x = scanner.Peek(); return la.kind == _lbrace && x.kind == _colon; } bool IsAlternative() { Token x = scanner.Peek(); return la.kind == _lbrace && x.val == "case"; } bool IsLoopSpec() { return la.val == "invariant" | la.val == "decreases" | la.val == "modifies"; } bool IsLoopSpecOrAlternative() { Token x = scanner.Peek(); return IsLoopSpec() || (la.kind == _lbrace && x.val == "case"); } bool IsParenStar() { scanner.ResetPeek(); Token x = scanner.Peek(); return la.kind == _openparen && x.kind == _star; } bool IsIdentParen() { Token x = scanner.Peek(); return la.kind == _ident && x.kind == _openparen; } bool SemiFollowsCall(bool allowSemi, Expression e) { return allowSemi && la.kind == _semi && (e is FunctionCallExpr || (e is IdentifierSequence && ((IdentifierSequence)e).OpenParen != null)); } bool CloseOptionalParen(bool usesOptionalParen) { return usesOptionalParen && la.kind == _closeparen; } bool CloseOptionalBrace(bool usesOptionalBrace) { return usesOptionalBrace && la.kind == _rbrace; } /*--------------------------------------------------------------------------*/ public Parser(Scanner/*!*/ scanner, Errors/*!*/ errors) { this.scanner = scanner; this.errors = errors; Token/*!*/ tok = new Token(); tok.val = ""; this.la = tok; this.t = new Token(); // just to satisfy its non-null constraint } void SynErr (int n) { if (errDist >= minErrDist) errors.SynErr(la.filename, la.line, la.col, n); errDist = 0; } public void SemErr (string/*!*/ msg) { Contract.Requires(msg != null); if (errDist >= minErrDist) errors.SemErr(t, msg); errDist = 0; } public void SemErr(IToken/*!*/ tok, string/*!*/ msg) { Contract.Requires(tok != null); Contract.Requires(msg != null); errors.SemErr(tok, msg); } void Get () { for (;;) { t = la; la = scanner.Scan(); if (la.kind <= maxT) { ++errDist; break; } la = t; } } void Expect (int n) { if (la.kind==n) Get(); else { SynErr(n); } } bool StartOf (int s) { return set[s, la.kind]; } void ExpectWeak (int n, int follow) { if (la.kind == n) Get(); else { SynErr(n); while (!StartOf(follow)) Get(); } } bool WeakSeparator(int n, int syFol, int repFol) { int kind = la.kind; if (kind == n) {Get(); return true;} else if (StartOf(repFol)) {return false;} else { SynErr(n); while (!(set[syFol, kind] || set[repFol, kind] || set[0, kind])) { Get(); kind = la.kind; } return StartOf(syFol); } } void Dafny() { ClassDecl/*!*/ c; DatatypeDecl/*!*/ dt; ArbitraryTypeDecl at; IteratorDecl iter; List membersDefaultClass = new List(); ModuleDecl submodule; // to support multiple files, create a default module only if theModule is null DefaultModuleDecl defaultModule = (DefaultModuleDecl)((LiteralModuleDecl)theModule).ModuleDef; // theModule should be a DefaultModuleDecl (actually, the singular DefaultModuleDecl) Contract.Assert(defaultModule != null); while (la.kind == 15) { Get(); Expect(6); { string parsedFile = t.filename; string includedFile = t.val.Substring(1, t.val.Length - 2); string fullPath = includedFile; if (!Path.IsPathRooted(includedFile)) { string basePath = Path.GetDirectoryName(parsedFile); includedFile = Path.Combine(basePath, includedFile); fullPath = Path.GetFullPath(includedFile); } defaultModule.Includes.Add(new Include(t, includedFile, fullPath)); } } while (StartOf(1)) { switch (la.kind) { case 16: case 17: case 19: { SubModuleDecl(defaultModule, out submodule); defaultModule.TopLevelDecls.Add(submodule); break; } case 24: { ClassDecl(defaultModule, out c); defaultModule.TopLevelDecls.Add(c); break; } case 27: case 28: { DatatypeDecl(defaultModule, out dt); defaultModule.TopLevelDecls.Add(dt); break; } case 32: { ArbitraryTypeDecl(defaultModule, out at); defaultModule.TopLevelDecls.Add(at); break; } case 34: { IteratorDecl(defaultModule, out iter); defaultModule.TopLevelDecls.Add(iter); break; } case 25: case 26: case 30: case 40: case 41: case 42: case 43: case 44: case 62: case 63: case 64: { ClassMemberDecl(membersDefaultClass, false); break; } } } DefaultClassDecl defaultClass = null; foreach (TopLevelDecl topleveldecl in defaultModule.TopLevelDecls) { defaultClass = topleveldecl as DefaultClassDecl; if (defaultClass != null) { defaultClass.Members.AddRange(membersDefaultClass); break; } } if (defaultClass == null) { // create the default class here, because it wasn't found defaultClass = new DefaultClassDecl(defaultModule, membersDefaultClass); defaultModule.TopLevelDecls.Add(defaultClass); } Expect(0); } void SubModuleDecl(ModuleDefinition parent, out ModuleDecl submodule) { ClassDecl/*!*/ c; DatatypeDecl/*!*/ dt; ArbitraryTypeDecl at; IteratorDecl iter; Attributes attrs = null; IToken/*!*/ id; List namedModuleDefaultClassMembers = new List();; List idRefined = null, idPath = null, idAssignment = null; ModuleDefinition module; ModuleDecl sm; submodule = null; // appease compiler bool isAbstract = false; bool opened = false; if (la.kind == 16 || la.kind == 17) { if (la.kind == 16) { Get(); isAbstract = true; } Expect(17); while (la.kind == 9) { Attribute(ref attrs); } NoUSIdent(out id); if (la.kind == 18) { Get(); QualifiedName(out idRefined); } module = new ModuleDefinition(id, id.val, isAbstract, false, idRefined == null ? null : idRefined, parent, attrs, false); Expect(9); module.BodyStartTok = t; while (StartOf(1)) { switch (la.kind) { case 16: case 17: case 19: { SubModuleDecl(module, out sm); module.TopLevelDecls.Add(sm); break; } case 24: { ClassDecl(module, out c); module.TopLevelDecls.Add(c); break; } case 27: case 28: { DatatypeDecl(module, out dt); module.TopLevelDecls.Add(dt); break; } case 32: { ArbitraryTypeDecl(module, out at); module.TopLevelDecls.Add(at); break; } case 34: { IteratorDecl(module, out iter); module.TopLevelDecls.Add(iter); break; } case 25: case 26: case 30: case 40: case 41: case 42: case 43: case 44: case 62: case 63: case 64: { ClassMemberDecl(namedModuleDefaultClassMembers, false); break; } } } Expect(10); module.BodyEndTok = t; module.TopLevelDecls.Add(new DefaultClassDecl(module, namedModuleDefaultClassMembers)); submodule = new LiteralModuleDecl(module, parent); } else if (la.kind == 19) { Get(); if (la.kind == 20) { Get(); opened = true; } NoUSIdent(out id); if (la.kind == 21 || la.kind == 22) { if (la.kind == 21) { Get(); QualifiedName(out idPath); submodule = new AliasModuleDecl(idPath, id, parent, opened); } else { Get(); QualifiedName(out idPath); if (la.kind == 23) { Get(); QualifiedName(out idAssignment); } submodule = new ModuleFacadeDecl(idPath, id, parent, idAssignment, opened); } } if (la.kind == 8) { while (!(la.kind == 0 || la.kind == 8)) {SynErr(127); Get();} Get(); } if (submodule == null) { idPath = new List(); idPath.Add(id); submodule = new AliasModuleDecl(idPath, id, parent, opened); } } else SynErr(128); } void ClassDecl(ModuleDefinition/*!*/ module, out ClassDecl/*!*/ c) { Contract.Requires(module != null); Contract.Ensures(Contract.ValueAtReturn(out c) != null); IToken/*!*/ id; Attributes attrs = null; List typeArgs = new List(); List members = new List(); IToken bodyStart; while (!(la.kind == 0 || la.kind == 24)) {SynErr(129); Get();} Expect(24); while (la.kind == 9) { Attribute(ref attrs); } NoUSIdent(out id); if (la.kind == 38) { GenericParameters(typeArgs); } Expect(9); bodyStart = t; while (StartOf(2)) { ClassMemberDecl(members, true); } Expect(10); c = new ClassDecl(id, id.val, module, typeArgs, members, attrs); c.BodyStartTok = bodyStart; c.BodyEndTok = t; } void DatatypeDecl(ModuleDefinition/*!*/ module, out DatatypeDecl/*!*/ dt) { Contract.Requires(module != null); Contract.Ensures(Contract.ValueAtReturn(out dt)!=null); IToken/*!*/ id; Attributes attrs = null; List typeArgs = new List(); List ctors = new List(); IToken bodyStart = Token.NoToken; // dummy assignment bool co = false; while (!(la.kind == 0 || la.kind == 27 || la.kind == 28)) {SynErr(130); Get();} if (la.kind == 27) { Get(); } else if (la.kind == 28) { Get(); co = true; } else SynErr(131); while (la.kind == 9) { Attribute(ref attrs); } NoUSIdent(out id); if (la.kind == 38) { GenericParameters(typeArgs); } Expect(21); bodyStart = t; DatatypeMemberDecl(ctors); while (la.kind == 29) { Get(); DatatypeMemberDecl(ctors); } if (la.kind == 8) { while (!(la.kind == 0 || la.kind == 8)) {SynErr(132); Get();} Get(); } if (co) { dt = new CoDatatypeDecl(id, id.val, module, typeArgs, ctors, attrs); } else { dt = new IndDatatypeDecl(id, id.val, module, typeArgs, ctors, attrs); } dt.BodyStartTok = bodyStart; dt.BodyEndTok = t; } void ArbitraryTypeDecl(ModuleDefinition/*!*/ module, out ArbitraryTypeDecl at) { IToken/*!*/ id; Attributes attrs = null; var eqSupport = TypeParameter.EqualitySupportValue.Unspecified; Expect(32); while (la.kind == 9) { Attribute(ref attrs); } NoUSIdent(out id); if (la.kind == 11) { Get(); Expect(33); Expect(12); eqSupport = TypeParameter.EqualitySupportValue.Required; } at = new ArbitraryTypeDecl(id, id.val, module, eqSupport, attrs); if (la.kind == 8) { while (!(la.kind == 0 || la.kind == 8)) {SynErr(133); Get();} Get(); } } void IteratorDecl(ModuleDefinition module, out IteratorDecl/*!*/ iter) { Contract.Ensures(Contract.ValueAtReturn(out iter) != null); IToken/*!*/ id; Attributes attrs = null; List/*!*/ typeArgs = new List(); IToken openParen; List ins = new List(); List outs = new List(); List reads = new List(); List mod = new List(); List decreases = new List(); List req = new List(); List ens = new List(); List yieldReq = new List(); List yieldEns = new List(); List dec = new List(); Attributes readsAttrs = null; Attributes modAttrs = null; Attributes decrAttrs = null; BlockStmt body = null; IToken signatureEllipsis = null; IToken bodyStart = Token.NoToken; IToken bodyEnd = Token.NoToken; while (!(la.kind == 0 || la.kind == 34)) {SynErr(134); Get();} Expect(34); while (la.kind == 9) { Attribute(ref attrs); } NoUSIdent(out id); if (la.kind == 11 || la.kind == 38) { if (la.kind == 38) { GenericParameters(typeArgs); } Formals(true, true, ins, out openParen); if (la.kind == 35 || la.kind == 36) { if (la.kind == 35) { Get(); } else { Get(); SemErr(t, "iterators don't have a 'returns' clause; did you mean 'yields'?"); } Formals(false, true, outs, out openParen); } } else if (la.kind == 37) { Get(); signatureEllipsis = t; openParen = Token.NoToken; } else SynErr(135); while (StartOf(3)) { IteratorSpec(reads, mod, decreases, req, ens, yieldReq, yieldEns, ref readsAttrs, ref modAttrs, ref decrAttrs); } if (la.kind == 9) { BlockStmt(out body, out bodyStart, out bodyEnd); } iter = new IteratorDecl(id, id.val, module, typeArgs, ins, outs, new Specification(reads, readsAttrs), new Specification(mod, modAttrs), new Specification(decreases, decrAttrs), req, ens, yieldReq, yieldEns, body, attrs, signatureEllipsis); iter.BodyStartTok = bodyStart; iter.BodyEndTok = bodyEnd; } void ClassMemberDecl(List/*!*/ mm, bool allowConstructors) { Contract.Requires(cce.NonNullElements(mm)); Method/*!*/ m; Function/*!*/ f; MemberModifiers mmod = new MemberModifiers(); while (la.kind == 25 || la.kind == 26) { if (la.kind == 25) { Get(); mmod.IsGhost = true; } else { Get(); mmod.IsStatic = true; } } if (la.kind == 30) { FieldDecl(mmod, mm); } else if (la.kind == 62 || la.kind == 63 || la.kind == 64) { FunctionDecl(mmod, out f); mm.Add(f); } else if (StartOf(4)) { MethodDecl(mmod, allowConstructors, out m); mm.Add(m); } else SynErr(136); } void Attribute(ref Attributes attrs) { Expect(9); AttributeBody(ref attrs); Expect(10); } void NoUSIdent(out IToken/*!*/ x) { Contract.Ensures(Contract.ValueAtReturn(out x) != null); Expect(1); x = t; if (x.val.StartsWith("_")) { SemErr("cannot declare identifier beginning with underscore"); } } void QualifiedName(out List ids) { IToken id; IToken idPrime; ids = new List(); Ident(out id); ids.Add(id); while (la.kind == 61) { IdentOrDigitsSuffix(out id, out idPrime); ids.Add(id); if (idPrime != null) { ids.Add(idPrime); } } } void Ident(out IToken/*!*/ x) { Contract.Ensures(Contract.ValueAtReturn(out x) != null); Expect(1); x = t; } void IdentOrDigitsSuffix(out IToken x, out IToken y) { Contract.Ensures(Contract.ValueAtReturn(out x) != null); x = Token.NoToken; y = null; Expect(61); if (la.kind == 1) { Get(); x = t; } else if (la.kind == 2) { Get(); x = t; } else if (la.kind == 4) { Get(); x = t; int exponent = x.val.IndexOf('e'); if (0 <= exponent) { // this is not a legal field/destructor name SemErr(x, "invalid IdentOrDigitsSuffix"); } else { int dot = x.val.IndexOf('.'); if (0 <= dot) { y = new Token(); y.pos = x.pos + dot + 1; y.val = x.val.Substring(dot + 1); x.val = x.val.Substring(0, dot); y.col = x.col + dot + 1; y.line = x.line; y.filename = x.filename; y.kind = x.kind; } } } else SynErr(137); } void GenericParameters(List/*!*/ typeArgs) { Contract.Requires(cce.NonNullElements(typeArgs)); IToken/*!*/ id; TypeParameter.EqualitySupportValue eqSupport; Expect(38); NoUSIdent(out id); eqSupport = TypeParameter.EqualitySupportValue.Unspecified; if (la.kind == 11) { Get(); Expect(33); Expect(12); eqSupport = TypeParameter.EqualitySupportValue.Required; } typeArgs.Add(new TypeParameter(id, id.val, eqSupport)); while (la.kind == 31) { Get(); NoUSIdent(out id); eqSupport = TypeParameter.EqualitySupportValue.Unspecified; if (la.kind == 11) { Get(); Expect(33); Expect(12); eqSupport = TypeParameter.EqualitySupportValue.Required; } typeArgs.Add(new TypeParameter(id, id.val, eqSupport)); } Expect(39); } void FieldDecl(MemberModifiers mmod, List/*!*/ mm) { Contract.Requires(cce.NonNullElements(mm)); Attributes attrs = null; IToken/*!*/ id; Type/*!*/ ty; while (!(la.kind == 0 || la.kind == 30)) {SynErr(138); Get();} Expect(30); if (mmod.IsStatic) { SemErr(t, "fields cannot be declared 'static'"); } while (la.kind == 9) { Attribute(ref attrs); } FIdentType(out id, out ty); mm.Add(new Field(id, id.val, mmod.IsGhost, ty, attrs)); while (la.kind == 31) { Get(); FIdentType(out id, out ty); mm.Add(new Field(id, id.val, mmod.IsGhost, ty, attrs)); } while (!(la.kind == 0 || la.kind == 8)) {SynErr(139); Get();} Expect(8); } void FunctionDecl(MemberModifiers mmod, out Function/*!*/ f) { Contract.Ensures(Contract.ValueAtReturn(out f)!=null); Attributes attrs = null; IToken/*!*/ id = Token.NoToken; // to please compiler List typeArgs = new List(); List formals = new List(); Type/*!*/ returnType = new BoolType(); List reqs = new List(); List ens = new List(); List reads = new List(); List decreases; Expression body = null; bool isPredicate = false; bool isCoPredicate = false; bool isFunctionMethod = false; IToken openParen = null; IToken bodyStart = Token.NoToken; IToken bodyEnd = Token.NoToken; IToken signatureEllipsis = null; if (la.kind == 62) { Get(); if (la.kind == 40) { Get(); isFunctionMethod = true; } if (mmod.IsGhost) { SemErr(t, "functions cannot be declared 'ghost' (they are ghost by default)"); } while (la.kind == 9) { Attribute(ref attrs); } NoUSIdent(out id); if (la.kind == 11 || la.kind == 38) { if (la.kind == 38) { GenericParameters(typeArgs); } Formals(true, isFunctionMethod, formals, out openParen); Expect(7); Type(out returnType); } else if (la.kind == 37) { Get(); signatureEllipsis = t; openParen = Token.NoToken; } else SynErr(140); } else if (la.kind == 63) { Get(); isPredicate = true; if (la.kind == 40) { Get(); isFunctionMethod = true; } if (mmod.IsGhost) { SemErr(t, "predicates cannot be declared 'ghost' (they are ghost by default)"); } while (la.kind == 9) { Attribute(ref attrs); } NoUSIdent(out id); if (StartOf(5)) { if (la.kind == 38) { GenericParameters(typeArgs); } if (la.kind == 11) { Formals(true, isFunctionMethod, formals, out openParen); if (la.kind == 7) { Get(); SemErr(t, "predicates do not have an explicitly declared return type; it is always bool"); } } } else if (la.kind == 37) { Get(); signatureEllipsis = t; openParen = Token.NoToken; } else SynErr(141); } else if (la.kind == 64) { Get(); isCoPredicate = true; if (mmod.IsGhost) { SemErr(t, "copredicates cannot be declared 'ghost' (they are ghost by default)"); } while (la.kind == 9) { Attribute(ref attrs); } NoUSIdent(out id); if (StartOf(5)) { if (la.kind == 38) { GenericParameters(typeArgs); } if (la.kind == 11) { Formals(true, isFunctionMethod, formals, out openParen); if (la.kind == 7) { Get(); SemErr(t, "copredicates do not have an explicitly declared return type; it is always bool"); } } } else if (la.kind == 37) { Get(); signatureEllipsis = t; openParen = Token.NoToken; } else SynErr(142); } else SynErr(143); decreases = isCoPredicate ? null : new List(); while (StartOf(6)) { FunctionSpec(reqs, reads, ens, decreases); } if (la.kind == 9) { FunctionBody(out body, out bodyStart, out bodyEnd); } if (DafnyOptions.O.DisallowSoundnessCheating && body == null && ens.Count > 0 && !Attributes.Contains(attrs, "axiom")) { SemErr(t, "a function with an ensures clause must have a body, unless given the :axiom attribute"); } IToken tok = theVerifyThisFile ? id : new IncludeToken(id); if (isPredicate) { f = new Predicate(tok, id.val, mmod.IsStatic, !isFunctionMethod, typeArgs, openParen, formals, reqs, reads, ens, new Specification(decreases, null), body, Predicate.BodyOriginKind.OriginalOrInherited, attrs, signatureEllipsis); } else if (isCoPredicate) { f = new CoPredicate(tok, id.val, mmod.IsStatic, typeArgs, openParen, formals, reqs, reads, ens, body, attrs, signatureEllipsis); } else { f = new Function(tok, id.val, mmod.IsStatic, !isFunctionMethod, typeArgs, openParen, formals, returnType, reqs, reads, ens, new Specification(decreases, null), body, attrs, signatureEllipsis); } f.BodyStartTok = bodyStart; f.BodyEndTok = bodyEnd; } void MethodDecl(MemberModifiers mmod, bool allowConstructor, out Method/*!*/ m) { Contract.Ensures(Contract.ValueAtReturn(out m) !=null); IToken/*!*/ id = Token.NoToken; bool hasName = false; IToken keywordToken; Attributes attrs = null; List/*!*/ typeArgs = new List(); IToken openParen; List ins = new List(); List outs = new List(); List req = new List(); List mod = new List(); List ens = new List(); List dec = new List(); Attributes decAttrs = null; Attributes modAttrs = null; BlockStmt body = null; bool isLemma = false; bool isConstructor = false; bool isCoLemma = false; IToken signatureEllipsis = null; IToken bodyStart = Token.NoToken; IToken bodyEnd = Token.NoToken; while (!(StartOf(7))) {SynErr(144); Get();} if (la.kind == 40) { Get(); } else if (la.kind == 41) { Get(); isLemma = true; } else if (la.kind == 42) { Get(); isCoLemma = true; } else if (la.kind == 43) { Get(); isCoLemma = true; errors.Warning(t, "the 'comethod' keyword has been deprecated; it has been renamed to 'colemma'"); } else if (la.kind == 44) { Get(); if (allowConstructor) { isConstructor = true; } else { SemErr(t, "constructors are only allowed in classes"); } } else SynErr(145); keywordToken = t; if (isLemma) { if (mmod.IsGhost) { SemErr(t, "lemmas cannot be declared 'ghost' (they are automatically 'ghost')"); } } else if (isConstructor) { if (mmod.IsGhost) { SemErr(t, "constructors cannot be declared 'ghost'"); } if (mmod.IsStatic) { SemErr(t, "constructors cannot be declared 'static'"); } } else if (isCoLemma) { if (mmod.IsGhost) { SemErr(t, "colemmas cannot be declared 'ghost' (they are automatically 'ghost')"); } } while (la.kind == 9) { Attribute(ref attrs); } if (la.kind == 1) { NoUSIdent(out id); hasName = true; } if (!hasName) { id = keywordToken; if (!isConstructor) { SemErr(la, "a method must be given a name (expecting identifier)"); } } if (la.kind == 11 || la.kind == 38) { if (la.kind == 38) { GenericParameters(typeArgs); } Formals(true, !mmod.IsGhost, ins, out openParen); if (la.kind == 36) { Get(); if (isConstructor) { SemErr(t, "constructors cannot have out-parameters"); } Formals(false, !mmod.IsGhost, outs, out openParen); } } else if (la.kind == 37) { Get(); signatureEllipsis = t; openParen = Token.NoToken; } else SynErr(146); while (StartOf(8)) { MethodSpec(req, mod, ens, dec, ref decAttrs, ref modAttrs); } if (la.kind == 9) { BlockStmt(out body, out bodyStart, out bodyEnd); } if (Attributes.Contains(attrs, "axiom") && !mmod.IsGhost && !isLemma) { SemErr(t, "only ghost methods can have the :axiom attribute"); } if (DafnyOptions.O.DisallowSoundnessCheating && body == null && ens.Count > 0 && !Attributes.Contains(attrs, "axiom")) { SemErr(t, "a method with an ensures clause must have a body, unless given the :axiom attribute"); } IToken tok = theVerifyThisFile ? id : new IncludeToken(id); if (isConstructor) { m = new Constructor(tok, hasName ? id.val : "_ctor", typeArgs, ins, req, new Specification(mod, modAttrs), ens, new Specification(dec, decAttrs), body, attrs, signatureEllipsis); } else if (isCoLemma) { m = new CoLemma(tok, id.val, mmod.IsStatic, typeArgs, ins, outs, req, new Specification(mod, modAttrs), ens, new Specification(dec, decAttrs), body, attrs, signatureEllipsis); } else if (isLemma) { m = new Lemma(tok, id.val, mmod.IsStatic, typeArgs, ins, outs, req, new Specification(mod, modAttrs), ens, new Specification(dec, decAttrs), body, attrs, signatureEllipsis); } else { m = new Method(tok, id.val, mmod.IsStatic, mmod.IsGhost, typeArgs, ins, outs, req, new Specification(mod, modAttrs), ens, new Specification(dec, decAttrs), body, attrs, signatureEllipsis); } m.BodyStartTok = bodyStart; m.BodyEndTok = bodyEnd; } void DatatypeMemberDecl(List/*!*/ ctors) { Contract.Requires(cce.NonNullElements(ctors)); Attributes attrs = null; IToken/*!*/ id; List formals = new List(); while (la.kind == 9) { Attribute(ref attrs); } NoUSIdent(out id); if (la.kind == 11) { FormalsOptionalIds(formals); } ctors.Add(new DatatypeCtor(id, id.val, formals, attrs)); } void FormalsOptionalIds(List/*!*/ formals) { Contract.Requires(cce.NonNullElements(formals)); IToken/*!*/ id; Type/*!*/ ty; string/*!*/ name; bool isGhost; Expect(11); if (StartOf(9)) { TypeIdentOptional(out id, out name, out ty, out isGhost); formals.Add(new Formal(id, name, ty, true, isGhost)); while (la.kind == 31) { Get(); TypeIdentOptional(out id, out name, out ty, out isGhost); formals.Add(new Formal(id, name, ty, true, isGhost)); } } Expect(12); } void FIdentType(out IToken/*!*/ id, out Type/*!*/ ty) { Contract.Ensures(Contract.ValueAtReturn(out id) != null); Contract.Ensures(Contract.ValueAtReturn(out ty) != null); id = Token.NoToken; if (la.kind == 1) { WildIdent(out id, false); } else if (la.kind == 2) { Get(); id = t; } else SynErr(147); Expect(7); Type(out ty); } void GIdentType(bool allowGhostKeyword, out IToken/*!*/ id, out Type/*!*/ ty, out bool isGhost) { Contract.Ensures(Contract.ValueAtReturn(out id)!=null); Contract.Ensures(Contract.ValueAtReturn(out ty)!=null); isGhost = false; if (la.kind == 25) { Get(); if (allowGhostKeyword) { isGhost = true; } else { SemErr(t, "formal cannot be declared 'ghost' in this context"); } } IdentType(out id, out ty, true); } void IdentType(out IToken/*!*/ id, out Type/*!*/ ty, bool allowWildcardId) { Contract.Ensures(Contract.ValueAtReturn(out id) != null); Contract.Ensures(Contract.ValueAtReturn(out ty) != null); WildIdent(out id, allowWildcardId); Expect(7); Type(out ty); } void WildIdent(out IToken/*!*/ x, bool allowWildcardId) { Contract.Ensures(Contract.ValueAtReturn(out x) != null); Expect(1); x = t; if (x.val.StartsWith("_")) { if (allowWildcardId && x.val.Length == 1) { t.val = "_v" + anonymousIds++; } else { SemErr("cannot declare identifier beginning with underscore"); } } } void Type(out Type/*!*/ ty) { Contract.Ensures(Contract.ValueAtReturn(out ty) != null); IToken/*!*/ tok; TypeAndToken(out tok, out ty); } void LocalIdentTypeOptional(out LocalVariable var, bool isGhost) { IToken id; Type ty; Type optType = null; WildIdent(out id, true); if (la.kind == 7) { Get(); Type(out ty); optType = ty; } var = new LocalVariable(id, id, id.val, optType == null ? new InferredTypeProxy() : optType, isGhost); } void IdentTypeOptional(out BoundVar var) { Contract.Ensures(Contract.ValueAtReturn(out var) != null); IToken id; Type ty; Type optType = null; WildIdent(out id, true); if (la.kind == 7) { Get(); Type(out ty); optType = ty; } var = new BoundVar(id, id.val, optType == null ? new InferredTypeProxy() : optType); } void TypeIdentOptional(out IToken/*!*/ id, out string/*!*/ identName, out Type/*!*/ ty, out bool isGhost) { Contract.Ensures(Contract.ValueAtReturn(out id)!=null); Contract.Ensures(Contract.ValueAtReturn(out ty)!=null); Contract.Ensures(Contract.ValueAtReturn(out identName)!=null); string name = null; id = Token.NoToken; ty = new BoolType()/*dummy*/; isGhost = false; if (la.kind == 25) { Get(); isGhost = true; } if (StartOf(10)) { TypeAndToken(out id, out ty); if (la.kind == 7) { Get(); UserDefinedType udt = ty as UserDefinedType; if (udt != null && udt.TypeArgs.Count == 0) { name = udt.Name; } else { SemErr(id, "invalid formal-parameter name in datatype constructor"); } Type(out ty); } } else if (la.kind == 2) { Get(); id = t; name = id.val; Expect(7); Type(out ty); } else SynErr(148); if (name != null) { identName = name; } else { identName = "#" + anonymousIds++; } } void TypeAndToken(out IToken/*!*/ tok, out Type/*!*/ ty) { Contract.Ensures(Contract.ValueAtReturn(out tok)!=null); Contract.Ensures(Contract.ValueAtReturn(out ty) != null); tok = Token.NoToken; ty = new BoolType(); /*keep compiler happy*/ List/*!*/ gt; switch (la.kind) { case 52: { Get(); tok = t; break; } case 53: { Get(); tok = t; ty = new NatType(); break; } case 54: { Get(); tok = t; ty = new IntType(); break; } case 55: { Get(); tok = t; ty = new RealType(); break; } case 56: { Get(); tok = t; gt = new List(); if (la.kind == 38) { GenericInstantiation(gt); } if (gt.Count > 1) { SemErr("set type expects only one type argument"); } ty = new SetType(gt.Count == 1 ? gt[0] : null); break; } case 57: { Get(); tok = t; gt = new List(); if (la.kind == 38) { GenericInstantiation(gt); } if (gt.Count > 1) { SemErr("multiset type expects only one type argument"); } ty = new MultiSetType(gt.Count == 1 ? gt[0] : null); break; } case 58: { Get(); tok = t; gt = new List(); if (la.kind == 38) { GenericInstantiation(gt); } if (gt.Count > 1) { SemErr("seq type expects only one type argument"); } ty = new SeqType(gt.Count == 1 ? gt[0] : null); break; } case 59: { Get(); tok = t; gt = new List(); if (la.kind == 38) { GenericInstantiation(gt); } if (gt.Count == 0) { ty = new MapType(null, null); } else if (gt.Count != 2) { SemErr("map type expects two type arguments"); ty = new MapType(gt[0], gt.Count == 1 ? new InferredTypeProxy() : gt[1]); } else { ty = new MapType(gt[0], gt[1]); } break; } case 1: case 5: case 60: { ReferenceType(out tok, out ty); break; } default: SynErr(149); break; } } void Formals(bool incoming, bool allowGhostKeyword, List/*!*/ formals, out IToken openParen) { Contract.Requires(cce.NonNullElements(formals)); IToken/*!*/ id; Type/*!*/ ty; bool isGhost; Expect(11); openParen = t; if (la.kind == 1 || la.kind == 25) { GIdentType(allowGhostKeyword, out id, out ty, out isGhost); formals.Add(new Formal(id, id.val, ty, incoming, isGhost)); while (la.kind == 31) { Get(); GIdentType(allowGhostKeyword, out id, out ty, out isGhost); formals.Add(new Formal(id, id.val, ty, incoming, isGhost)); } } Expect(12); } void IteratorSpec(List/*!*/ reads, List/*!*/ mod, List decreases, List/*!*/ req, List/*!*/ ens, List/*!*/ yieldReq, List/*!*/ yieldEns, ref Attributes readsAttrs, ref Attributes modAttrs, ref Attributes decrAttrs) { Expression/*!*/ e; FrameExpression/*!*/ fe; bool isFree = false; bool isYield = false; Attributes ensAttrs = null; while (!(StartOf(11))) {SynErr(150); Get();} if (la.kind == 50) { Get(); while (IsAttribute()) { Attribute(ref readsAttrs); } if (StartOf(12)) { FrameExpression(out fe); reads.Add(fe); while (la.kind == 31) { Get(); FrameExpression(out fe); reads.Add(fe); } } while (!(la.kind == 0 || la.kind == 8)) {SynErr(151); Get();} Expect(8); } else if (la.kind == 45) { Get(); while (IsAttribute()) { Attribute(ref modAttrs); } if (StartOf(12)) { FrameExpression(out fe); mod.Add(fe); while (la.kind == 31) { Get(); FrameExpression(out fe); mod.Add(fe); } } while (!(la.kind == 0 || la.kind == 8)) {SynErr(152); Get();} Expect(8); } else if (StartOf(13)) { if (la.kind == 46) { Get(); isFree = true; } if (la.kind == 51) { Get(); isYield = true; } if (la.kind == 47) { Get(); Expression(out e, false); while (!(la.kind == 0 || la.kind == 8)) {SynErr(153); Get();} Expect(8); if (isYield) { yieldReq.Add(new MaybeFreeExpression(e, isFree)); } else { req.Add(new MaybeFreeExpression(e, isFree)); } } else if (la.kind == 48) { Get(); while (IsAttribute()) { Attribute(ref ensAttrs); } Expression(out e, false); while (!(la.kind == 0 || la.kind == 8)) {SynErr(154); Get();} Expect(8); if (isYield) { yieldEns.Add(new MaybeFreeExpression(e, isFree, ensAttrs)); } else { ens.Add(new MaybeFreeExpression(e, isFree, ensAttrs)); } } else SynErr(155); } else if (la.kind == 49) { Get(); while (IsAttribute()) { Attribute(ref decrAttrs); } DecreasesList(decreases, false); while (!(la.kind == 0 || la.kind == 8)) {SynErr(156); Get();} Expect(8); } else SynErr(157); } void BlockStmt(out BlockStmt/*!*/ block, out IToken bodyStart, out IToken bodyEnd) { Contract.Ensures(Contract.ValueAtReturn(out block) != null); List body = new List(); Expect(9); bodyStart = t; while (StartOf(14)) { Stmt(body); } Expect(10); bodyEnd = t; block = new BlockStmt(bodyStart, bodyEnd, body); } void MethodSpec(List/*!*/ req, List/*!*/ mod, List/*!*/ ens, List/*!*/ decreases, ref Attributes decAttrs, ref Attributes modAttrs) { Contract.Requires(cce.NonNullElements(req)); Contract.Requires(cce.NonNullElements(mod)); Contract.Requires(cce.NonNullElements(ens)); Contract.Requires(cce.NonNullElements(decreases)); Expression/*!*/ e; FrameExpression/*!*/ fe; bool isFree = false; Attributes ensAttrs = null; while (!(StartOf(15))) {SynErr(158); Get();} if (la.kind == 45) { Get(); while (IsAttribute()) { Attribute(ref modAttrs); } if (StartOf(12)) { FrameExpression(out fe); mod.Add(fe); while (la.kind == 31) { Get(); FrameExpression(out fe); mod.Add(fe); } } while (!(la.kind == 0 || la.kind == 8)) {SynErr(159); Get();} Expect(8); } else if (la.kind == 46 || la.kind == 47 || la.kind == 48) { if (la.kind == 46) { Get(); isFree = true; } if (la.kind == 47) { Get(); Expression(out e, false); while (!(la.kind == 0 || la.kind == 8)) {SynErr(160); Get();} Expect(8); req.Add(new MaybeFreeExpression(e, isFree)); } else if (la.kind == 48) { Get(); while (IsAttribute()) { Attribute(ref ensAttrs); } Expression(out e, false); while (!(la.kind == 0 || la.kind == 8)) {SynErr(161); Get();} Expect(8); ens.Add(new MaybeFreeExpression(e, isFree, ensAttrs)); } else SynErr(162); } else if (la.kind == 49) { Get(); while (IsAttribute()) { Attribute(ref decAttrs); } DecreasesList(decreases, true); while (!(la.kind == 0 || la.kind == 8)) {SynErr(163); Get();} Expect(8); } else SynErr(164); } void FrameExpression(out FrameExpression/*!*/ fe) { Contract.Ensures(Contract.ValueAtReturn(out fe) != null); Expression/*!*/ e; IToken/*!*/ id; string fieldName = null; IToken feTok = null; fe = null; if (StartOf(16)) { Expression(out e, false); feTok = e.tok; if (la.kind == 65) { Get(); Ident(out id); fieldName = id.val; feTok = id; } fe = new FrameExpression(feTok, e, fieldName); } else if (la.kind == 65) { Get(); Ident(out id); fieldName = id.val; fe = new FrameExpression(id, new ImplicitThisExpr(id), fieldName); } else SynErr(165); } void Expression(out Expression e, bool allowSemi) { Expression e0; IToken endTok; EquivExpression(out e, allowSemi); if (SemiFollowsCall(allowSemi, e)) { Expect(8); endTok = t; Expression(out e0, allowSemi); e = new StmtExpr(e.tok, new UpdateStmt(e.tok, endTok, new List(), new List() { new ExprRhs(e, null) }), e0); } } void DecreasesList(List decreases, bool allowWildcard) { Expression/*!*/ e; PossiblyWildExpression(out e); if (!allowWildcard && e is WildcardExpr) { SemErr(e.tok, "'decreases *' is only allowed on loops and tail-recursive methods"); } else { decreases.Add(e); } while (la.kind == 31) { Get(); PossiblyWildExpression(out e); if (!allowWildcard && e is WildcardExpr) { SemErr(e.tok, "'decreases *' is only allowed on loops and tail-recursive methods"); } else { decreases.Add(e); } } } void GenericInstantiation(List/*!*/ gt) { Contract.Requires(cce.NonNullElements(gt)); Type/*!*/ ty; Expect(38); Type(out ty); gt.Add(ty); while (la.kind == 31) { Get(); Type(out ty); gt.Add(ty); } Expect(39); } void ReferenceType(out IToken/*!*/ tok, out Type/*!*/ ty) { Contract.Ensures(Contract.ValueAtReturn(out tok) != null); Contract.Ensures(Contract.ValueAtReturn(out ty) != null); tok = Token.NoToken; ty = new BoolType(); /*keep compiler happy*/ List/*!*/ gt; List path; if (la.kind == 60) { Get(); tok = t; ty = new ObjectType(); } else if (la.kind == 5) { Get(); tok = t; gt = new List(); GenericInstantiation(gt); if (gt.Count != 1) { SemErr("array type expects exactly one type argument"); } int dims = 1; if (tok.val.Length != 5) { dims = int.Parse(tok.val.Substring(5)); } ty = theBuiltIns.ArrayType(tok, dims, gt[0], true); } else if (la.kind == 1) { Ident(out tok); gt = new List(); path = new List(); while (la.kind == 61) { path.Add(tok); Get(); Ident(out tok); } if (la.kind == 38) { GenericInstantiation(gt); } ty = (tok.val == "real") ? (Type)Microsoft.Dafny.Type.Real : new UserDefinedType(tok, tok.val, gt, path); } else SynErr(166); } void FunctionSpec(List/*!*/ reqs, List/*!*/ reads, List/*!*/ ens, List decreases) { Contract.Requires(cce.NonNullElements(reqs)); Contract.Requires(cce.NonNullElements(reads)); Contract.Requires(decreases == null || cce.NonNullElements(decreases)); Expression/*!*/ e; FrameExpression/*!*/ fe; if (la.kind == 47) { while (!(la.kind == 0 || la.kind == 47)) {SynErr(167); Get();} Get(); Expression(out e, false); while (!(la.kind == 0 || la.kind == 8)) {SynErr(168); Get();} Expect(8); reqs.Add(e); } else if (la.kind == 50) { Get(); if (StartOf(17)) { PossiblyWildFrameExpression(out fe); reads.Add(fe); while (la.kind == 31) { Get(); PossiblyWildFrameExpression(out fe); reads.Add(fe); } } while (!(la.kind == 0 || la.kind == 8)) {SynErr(169); Get();} Expect(8); } else if (la.kind == 48) { Get(); Expression(out e, false); while (!(la.kind == 0 || la.kind == 8)) {SynErr(170); Get();} Expect(8); ens.Add(e); } else if (la.kind == 49) { Get(); if (decreases == null) { SemErr(t, "'decreases' clauses are meaningless for copredicates, so they are not allowed"); decreases = new List(); } DecreasesList(decreases, false); while (!(la.kind == 0 || la.kind == 8)) {SynErr(171); Get();} Expect(8); } else SynErr(172); } void FunctionBody(out Expression/*!*/ e, out IToken bodyStart, out IToken bodyEnd) { Contract.Ensures(Contract.ValueAtReturn(out e) != null); e = dummyExpr; Expect(9); bodyStart = t; Expression(out e, true); Expect(10); bodyEnd = t; } void PossiblyWildFrameExpression(out FrameExpression/*!*/ fe) { Contract.Ensures(Contract.ValueAtReturn(out fe) != null); fe = dummyFrameExpr; if (la.kind == 13) { Get(); fe = new FrameExpression(t, new WildcardExpr(t), null); } else if (StartOf(12)) { FrameExpression(out fe); } else SynErr(173); } void PossiblyWildExpression(out Expression/*!*/ e) { Contract.Ensures(Contract.ValueAtReturn(out e)!=null); e = dummyExpr; if (la.kind == 13) { Get(); e = new WildcardExpr(t); } else if (StartOf(16)) { Expression(out e, false); } else SynErr(174); } void Stmt(List/*!*/ ss) { Statement/*!*/ s; OneStmt(out s); ss.Add(s); } void OneStmt(out Statement/*!*/ s) { Contract.Ensures(Contract.ValueAtReturn(out s) != null); IToken/*!*/ x; IToken/*!*/ id; string label = null; s = dummyStmt; /* to please the compiler */ BlockStmt bs; IToken bodyStart, bodyEnd; int breakCount; while (!(StartOf(18))) {SynErr(175); Get();} switch (la.kind) { case 9: { BlockStmt(out bs, out bodyStart, out bodyEnd); s = bs; break; } case 83: { AssertStmt(out s); break; } case 72: { AssumeStmt(out s); break; } case 84: { PrintStmt(out s); break; } case 1: case 2: case 3: case 4: case 11: case 29: case 54: case 55: case 113: case 114: case 115: case 116: case 117: case 118: { UpdateStmt(out s); break; } case 25: case 30: { VarDeclStatement(out s); break; } case 76: { IfStmt(out s); break; } case 80: { WhileStmt(out s); break; } case 82: { MatchStmt(out s); break; } case 85: case 86: { ForallStmt(out s); break; } case 88: { CalcStmt(out s); break; } case 87: { ModifyStmt(out s); break; } case 66: { Get(); x = t; NoUSIdent(out id); Expect(7); OneStmt(out s); s.Labels = new LList