diff options
author | Dan Liew <daniel.liew@imperial.ac.uk> | 2015-06-28 01:44:30 +0100 |
---|---|---|
committer | Dan Liew <daniel.liew@imperial.ac.uk> | 2015-06-28 01:44:30 +0100 |
commit | 962f8d5252b3f5ec4d19e0cd2a430934bd55cc6d (patch) | |
tree | 27d5f9b0d130c6c1a6758bc0b7456b0aa51e34e0 /Source/Core/ResolutionContext.cs | |
parent | e11d65009d0b4ba1327f5f5dd6b26367330611f0 (diff) |
Normalise line endings using a .gitattributes file. Unfortunately
this required that this commit globally modify most files. If you
want to use git blame to see the real author of a line use the
``-w`` flag so that whitespace changes are ignored.
Diffstat (limited to 'Source/Core/ResolutionContext.cs')
-rw-r--r-- | Source/Core/ResolutionContext.cs | 1258 |
1 files changed, 629 insertions, 629 deletions
diff --git a/Source/Core/ResolutionContext.cs b/Source/Core/ResolutionContext.cs index bf1a5629..474a91dd 100644 --- a/Source/Core/ResolutionContext.cs +++ b/Source/Core/ResolutionContext.cs @@ -1,629 +1,629 @@ -//-----------------------------------------------------------------------------
-//
-// Copyright (C) Microsoft Corporation. All Rights Reserved.
-//
-//-----------------------------------------------------------------------------
-namespace Microsoft.Boogie {
- using System.Collections;
- using System.Collections.Generic;
- using System;
- using System.Linq;
- using System.Diagnostics.Contracts;
-
- [ContractClass(typeof(IErrorSinkContracts))]
- public interface IErrorSink {
- void Error(IToken/*!*/ tok, string/*!*/ msg);
- }
- [ContractClassFor(typeof(IErrorSink))]
- public abstract class IErrorSinkContracts : IErrorSink {
- #region IErrorSink Members
- public void Error(IToken tok, string msg) {
- Contract.Requires(tok != null);
- Contract.Requires(msg != null);
- throw new NotImplementedException();
- }
- #endregion
- }
-
- public class CheckingContext {
- // ------------------------------ Error counting ------------------------------
-
- IErrorSink errorSink;
- int errors;
-
- public CheckingContext(IErrorSink errorSink) {
- this.errorSink = errorSink;
- }
-
- public int ErrorCount {
- get {
- return errors;
- }
- set {
- errors = value;
- }
- }
-
- public void Error(Absy subject, string msg, params object[] args) {
- Contract.Requires(args != null);
- Contract.Requires(msg != null);
- Contract.Requires(subject != null);
- Error(subject.tok, msg, args);
- }
-
- public virtual void Error(IToken tok, string msg) {
- Contract.Requires(msg != null);
- Contract.Requires(tok != null);
- errors++;
- if (errorSink == null) {
- ConsoleColor col = Console.ForegroundColor;
- Console.ForegroundColor = ConsoleColor.Red;
- Console.WriteLine("{0}({1},{2}): Error: {3}",
- tok.filename, tok.line, tok.col - 1,
- msg);
- Console.ForegroundColor = col;
- } else {
- errorSink.Error(tok, msg);
- }
- }
-
- private string Format(string msg, params object[] args) {
- Contract.Requires(msg != null);
- Contract.Ensures(Contract.Result<string>() != null);
- if (System.Type.GetType("Mono.Runtime") != null) { // MONO
- // something in mono seems to be broken so that calling
- // NamedDeclarations.ToString (and similar ToString methods)
- // causes a stack overflow. We therefore convert those to
- // strings by hand
- object[] fixedArgs = new object[cce.NonNull(args).Length];
- for (int i = 0; i < args.Length; ++i) {
- if (args[i] is NamedDeclaration) {
- fixedArgs[i] = cce.NonNull((NamedDeclaration)args[i]).Name;
- } else if (args[i] is Type) {
- System.IO.StringWriter buffer = new System.IO.StringWriter();
- using (TokenTextWriter stream = new TokenTextWriter("<buffer>", buffer, /*setTokens=*/ false, /*pretty=*/ false)) {
- cce.NonNull((Type)args[i]).Emit(stream);
- }
- fixedArgs[i] = buffer.ToString();
- } else if (args[i] is Expr) {
- System.IO.StringWriter buffer = new System.IO.StringWriter();
- using (TokenTextWriter stream = new TokenTextWriter("<buffer>", buffer, /*setTokens=*/ false, /*pretty=*/ false)) {
- cce.NonNull((Expr/*!*/)args[i]).Emit(stream, 0, false);
- }
- fixedArgs[i] = buffer.ToString();
- } else {
- fixedArgs[i] = args[i];
- }
- }
- args = fixedArgs;
- }
- return string.Format(msg, args);
- }
-
- public void Error(IToken tok, string msg, params object[] args) {
- Contract.Requires(msg != null);
- Contract.Requires(tok != null);
- Error(tok, Format(msg, args));
- }
-
- public void Warning(Absy subject, string msg, params object[] args) {
- Contract.Requires(args != null);
- Contract.Requires(msg != null);
- Contract.Requires(subject != null);
- Warning(subject.tok, msg, args);
- }
-
- public virtual void Warning(IToken tok, string msg) {
- Contract.Requires(msg != null);
- Contract.Requires(tok != null);
- // warnings are currently always written to the console
- ConsoleColor col = Console.ForegroundColor;
- Console.ForegroundColor = ConsoleColor.DarkYellow;
- Console.WriteLine("{0}({1},{2}): Warning: {3}",
- tok.filename, tok.line, tok.col - 1,
- msg);
- Console.ForegroundColor = col;
- }
-
- public void Warning(IToken tok, string msg, params object[] args) {
- Contract.Requires(msg != null);
- Contract.Requires(tok != null);
- Warning(tok, Format(msg, args));
- }
- }
-
- public class ResolutionContext : CheckingContext {
- public ResolutionContext(IErrorSink errorSink)
- : base(errorSink) {
- }
-
- // ------------------------------ Boogie 2 Types -------------------------
-
- // user-defined types, which can be either TypeCtorDecl or TypeSynonymDecl
- Hashtable /*string->NamedDeclaration*//*!*/ types = new Hashtable /*string->NamedDeclaration*/ ();
- [ContractInvariantMethod]
- void ObjectInvariant() {
- Contract.Invariant(types != null);
- Contract.Invariant(cce.NonNullElements(typeBinders));
- Contract.Invariant(varContext != null);
- Contract.Invariant(funcdures != null);
- }
-
-
- /// <summary>
- /// Checks if name coincides with the name of a bitvector type. If so, reports an error and
- /// returns true; otherwise, returns false.
- /// </summary>
- private bool CheckBvNameClashes(Absy absy, string name) {
- Contract.Requires(name != null);
- Contract.Requires(absy != null);
- if (name.StartsWith("bv") && name.Length > 2) {
- for (int i = 2; i < name.Length; ++i)
- if (!char.IsDigit(name[i]))
- return false;
- Error(absy, "type name: {0} is registered for bitvectors", name);
- return true;
- }
- return false;
- }
-
- public void AddType(NamedDeclaration td) {
- Contract.Requires(td != null);
- Contract.Requires((td is TypeCtorDecl) || (td is TypeSynonymDecl));
- Contract.Requires(td.Name != null);
-
- string name = td.Name;
- if (CheckBvNameClashes(td, name))
- return; // error has already been reported
-
- var previous = (NamedDeclaration)types[name];
- if (previous == null) {
- types.Add(name, td);
- } else {
- var r = (NamedDeclaration)SelectNonExtern(td, previous);
- if (r == null) {
- Error(td, "more than one declaration of type name: {0}", name);
- } else {
- types[name] = r;
- }
- }
- }
-
- /// <summary>
- /// Returns the declaration of the named type, or null if
- /// no such type is declared. Also return null if the type
- /// declared with the given name is not a constructor but a
- /// type synonym
- /// </summary>
- /// <param name="name"></param>
- /// <returns></returns>
- public TypeCtorDecl LookUpType(string name) {
- Contract.Requires(name != null);
- return types[name] as TypeCtorDecl;
- }
-
- public TypeSynonymDecl LookUpTypeSynonym(string name) {
- Contract.Requires(name != null);
- return types[name] as TypeSynonymDecl;
- }
-
- // ------------------------------ Boogie 2 Type Binders ------------------------------
-
- List<TypeVariable/*!*/>/*!*/ typeBinders = new List<TypeVariable/*!*/>(5);
-
- public void AddTypeBinder(TypeVariable td) {
- Contract.Requires(td != null);
- if (CheckBvNameClashes(td, td.Name)) {
- return;
- }
- if (types.ContainsKey(td.Name)) {
- Error(td, "name is already reserved for type constructor: {0}", td.Name);
- return;
- }
- for (int i = 0; i < typeBinders.Count; i++) {
- if (typeBinders[i].Name == td.Name) {
- Error(td, "more than one declaration of type variable: {0}", td.Name);
- return;
- }
- }
- typeBinders.Add(td);
- }
-
- public int TypeBinderState {
- get {
- return typeBinders.Count;
- }
- set {
- typeBinders.RemoveRange(value, typeBinders.Count - value);
- }
- }
-
- /// <summary>
- /// Returns the declaration of the named type binder, or null if
- /// no such binder is declared.
- /// </summary>
- public TypeVariable LookUpTypeBinder(string name) {
- Contract.Requires(name != null);
- for (int i = typeBinders.Count; 0 <= --i; ) {
- TypeVariable/*!*/ td = typeBinders[i];
- Contract.Assert(td != null);
- if (td.Name == name) {
- return td;
- }
- }
- return null; // not present
- }
-
- // ------------------------------ Variables ------------------------------
-
- class VarContextNode {
- [ContractInvariantMethod]
- void ObjectInvariant() {
- Contract.Invariant(VarSymbols != null);
- }
-
- public readonly Hashtable /*string->Variable*//*!*/ VarSymbols = new Hashtable /*string->Variable*/();
- public /*maybe null*/ VarContextNode ParentContext;
- public readonly bool Opaque;
- readonly ISet<string> assignedAssumptionVariables = new HashSet<string>();
-
- public bool HasVariableBeenAssigned(string name)
- {
- Contract.Requires(name != null);
-
- if (assignedAssumptionVariables.Contains(name))
- {
- return true;
- }
- else if (ParentContext != null)
- {
- return ParentContext.HasVariableBeenAssigned(name);
- }
- else
- {
- return false;
- }
- }
-
- public bool MarkVariableAsAssigned(string name)
- {
- Contract.Requires(name != null);
-
- if (VarSymbols.Contains(name))
- {
- if (assignedAssumptionVariables.Contains(name))
- {
- return false;
- }
- assignedAssumptionVariables.Add(name);
- return true;
- }
- else if (ParentContext != null)
- {
- return ParentContext.MarkVariableAsAssigned(name);
- }
- else
- {
- return false;
- }
- }
-
- public VarContextNode(/*maybe null*/ VarContextNode parentContext, bool opaque) {
- ParentContext = parentContext;
- Opaque = opaque;
- }
- }
-
- // symbolic constants, global variables, local variables, formals, expression-bound variables
- VarContextNode/*!*/ varContext = new VarContextNode(null, false);
-
- /// <summary>
- /// Adds a variable context.
- /// </summary>
- public void PushVarContext() {
- varContext = new VarContextNode(varContext, false);
- }
-
- /// <summary>
- /// Adds an opaque variable context, that is, one that blocks all previously pushed contexts.
- /// </summary>
- public void PushOpaqueVarContext() {
- varContext = new VarContextNode(varContext, true);
- }
-
- /// <summary>
- /// Requires there to be more than one variable context.
- /// </summary>
- public void PopVarContext() {
- Contract.Assert(varContext.ParentContext != null);
- varContext = varContext.ParentContext;
- }
-
- public void AddVariable(Variable var, bool global) {
- Contract.Requires(var != null);
- var previous = FindVariable(cce.NonNull(var.Name), !global);
- if (previous == null) {
- varContext.VarSymbols.Add(var.Name, var);
- } else {
- var r = (Variable)SelectNonExtern(var, previous);
- if (r == null) {
- Error(var, "more than one declaration of variable name: {0}", var.Name);
- } else {
- varContext.VarSymbols[var.Name] = r;
- }
- }
- }
-
- /// <summary>
- /// Returns the declaration of the named variable, or null if
- /// no such variable is declared.
- /// </summary>
- /// <param name="name"></param>
- /// <returns></returns>
- public Variable LookUpVariable(string name) {
- Contract.Requires(name != null);
- return FindVariable(name, false);
- }
-
- Variable FindVariable(string name, bool ignoreTopLevelVars) {
- Contract.Requires(name != null);
- VarContextNode c = varContext;
- bool lookOnlyForConstants = false;
- do {
- if (ignoreTopLevelVars && c.ParentContext == null) {
- // this is the top level and we're asked to ignore the top level; hence, we're done
- break;
- }
-
- Variable var = (Variable)c.VarSymbols[name];
- if (var != null && (!lookOnlyForConstants || var is Constant)) {
- return var;
- }
- // not at this level
-
- if (c.Opaque) {
- // from here on, only constants can be looked up
- lookOnlyForConstants = true;
- }
- c = c.ParentContext;
- } while (c != null);
-
- // not present in the relevant levels
- return null;
- }
-
- public bool HasVariableBeenAssigned(string name)
- {
- Contract.Requires(name != null);
-
- return varContext.HasVariableBeenAssigned(name);
- }
-
- public void MarkVariableAsAssigned(string name)
- {
- Contract.Requires(name != null);
-
- var success = varContext.MarkVariableAsAssigned(name);
- Contract.Assume(success);
- }
-
- Hashtable axioms = new Hashtable();
-
- public void AddAxiom(Axiom axiom) {
- string axiomName = QKeyValue.FindStringAttribute(axiom.Attributes, "name");
- if (axiomName == null)
- return;
- var previous = (Axiom)axioms[axiomName];
- if (previous == null) {
- axioms.Add(axiomName, axiom);
- }
- else {
- var r = (Axiom)SelectNonExtern(axiom, previous);
- if (r == null) {
- Error(axiom, "more than one declaration of axiom name: {0}", axiomName);
- }
- else {
- axioms[axiomName] = r;
- }
- }
- }
-
- // ------------------------------ Functions/Procedures ------------------------------
-
- // uninterpreted function symbols, procedures
- Hashtable /*string->DeclWithFormals*//*!*/ funcdures = new Hashtable /*string->DeclWithFormals*/ ();
-
- public void AddProcedure(DeclWithFormals proc) {
- Contract.Requires(proc != null);
- Contract.Requires(proc.Name != null);
-
- string name = proc.Name;
- var previous = (DeclWithFormals)funcdures[name];
- if (previous == null) {
- funcdures.Add(name, proc);
- } else {
- var r = (DeclWithFormals)SelectNonExtern(proc, previous);
- if (r == null) {
- Error(proc, "more than one declaration of function/procedure name: {0}", name);
- } else {
- funcdures[name] = r;
- }
- }
- }
-
- /// <summary>
- /// If both "a" and "b" have an ":extern" attribute, returns either one.
- /// If one of "a" and "b" has an ":extern" attribute, returns that one.
- /// If neither of "a" and "b" has an ":extern" attribute, returns null.
- /// If a non-value value is returned, this method also adds the ":ignore"
- /// attribute to the declaration NOT returned.
- /// </summary>
- Declaration SelectNonExtern(Declaration a, Declaration b) {
- Contract.Requires(a != null);
- Contract.Requires(b != null);
- Contract.Ensures(Contract.Result<Declaration>() == null || Contract.Result<Declaration>() == a || Contract.Result<Declaration>() == b);
-
- Declaration ignore, keep;
- if (QKeyValue.FindBoolAttribute(a.Attributes, "extern")) {
- ignore = a;
- keep = b;
- } else if (QKeyValue.FindBoolAttribute(b.Attributes, "extern")) {
- ignore = b;
- keep = a;
- } else {
- return null;
- }
- // prepend :ignore attribute
- ignore.Attributes = new QKeyValue(ignore.tok, "ignore", new List<object/*!*/>(), ignore.Attributes);
- return keep;
- }
-
- /// <summary>
- /// Returns the declaration of the named function/procedure, or null if
- /// no such function or procedure is declared.
- /// </summary>
- /// <param name="name"></param>
- /// <returns></returns>
- public DeclWithFormals LookUpProcedure(string name) {
- Contract.Requires(name != null);
- return (DeclWithFormals)funcdures[name];
- }
-
- // ------------------------------ Blocks ------------------------------
-
- class ProcedureContext {
- [ContractInvariantMethod]
- void ObjectInvariant() {
- Contract.Invariant(Blocks != null);
- }
-
- public readonly Hashtable/*!*/ /*string->Block!*/ Blocks;
- public readonly ProcedureContext Next;
- public ProcedureContext(ProcedureContext next) {
- Blocks = new Hashtable /*string->Block!*/ ();
- Next = next;
- }
- }
- /*maybe null*/
- ProcedureContext procedureContext; // stack of procedure contexts
- public bool HasProcedureContext {
- get {
- return procedureContext != null;
- }
- }
-
- /// <summary>
- /// Pushes a new procedure context.
- /// </summary>
- public void PushProcedureContext() {
- Contract.Ensures(HasProcedureContext);
- procedureContext = new ProcedureContext(procedureContext);
- }
-
- /// <summary>
- /// Requires there to be a procedure context. Pops it.
- /// </summary>
- public void PopProcedureContext() {
- Contract.Requires(HasProcedureContext);
- Contract.Assert(procedureContext != null); // follows from precondition
- procedureContext = procedureContext.Next;
- }
-
- /// <summary>
- /// Requires there to be a procedure context.
- /// </summary>
- /// <param name="block"></param>
- public void AddBlock(Block block) {
- Contract.Requires(block != null);
- Contract.Requires(HasProcedureContext);
- Contract.Assert(procedureContext != null); // follows from precondition
- Hashtable/*!*/ /*string->Block!*/ blocks = procedureContext.Blocks;
- Contract.Assert(blocks != null);
- if (blocks[block.Label] != null) {
- Error(block, "more than one declaration of block name: {0}", block.Label);
- } else {
- blocks.Add(block.Label, block);
- }
- }
-
- /// <summary>
- /// Requires there to be a procedure context.
- /// Returns the declaration of the named block, or null if
- /// no such block is declared.
- /// </summary>
- /// <param name="name"></param>
- /// <returns></returns>
- public Block LookUpBlock(string name) {
- Contract.Requires(name != null);
- Contract.Requires(HasProcedureContext);
- Contract.Assert(procedureContext != null); // follows from precondition
- Hashtable/*!*/ /*string->Block!*/ blocks = procedureContext.Blocks;
- Contract.Assert(blocks != null);
- return (Block)blocks[name];
- }
-
- // ------------------------------ Flags ------------------------------
-
- public enum State {
- StateLess,
- Single,
- Two
- }
- State stateMode = State.Single;
-
- /// <summary>
- /// To increase our confidence in that the caller knows what it's doing, we only allow
- /// the state mode to be changed in and out of the State.Single mode.
- /// </summary>
- public State StateMode {
- get {
- return stateMode;
- }
- set {
- Contract.Assert(value != stateMode);
- Contract.Assert(stateMode == State.Single || value == State.Single);
- cce.BeginExpose(this);
- {
- stateMode = value;
- }
- cce.EndExpose();
- }
- }
-
- bool triggerMode = false;
-
- /// <summary>
- /// Setting TriggerMode is allowed only if the setting has the effect of toggling the
- /// boolean. That is, TriggerMode can be set to true only if it previously was false,
- /// and TriggerMode can be set to false only if it previously was true.
- /// </summary>
- public bool TriggerMode {
- get {
- return triggerMode;
- }
- set {
- Contract.Assert(triggerMode != value);
- cce.BeginExpose(this);
- {
- triggerMode = value;
- }
- cce.EndExpose();
- }
- }
- }
-
- public class TypecheckingContext : CheckingContext {
- public List<IdentifierExpr> Frame; // used in checking the assignment targets of implementation bodies
- public bool Yields;
-
- public TypecheckingContext(IErrorSink errorSink)
- : base(errorSink) {
- }
-
- public bool InFrame(Variable v) {
- Contract.Requires(v != null);
- Contract.Requires(Frame != null);
- return Frame.Any(f => f.Decl == v);
- }
- }
-}
+//----------------------------------------------------------------------------- +// +// Copyright (C) Microsoft Corporation. All Rights Reserved. +// +//----------------------------------------------------------------------------- +namespace Microsoft.Boogie { + using System.Collections; + using System.Collections.Generic; + using System; + using System.Linq; + using System.Diagnostics.Contracts; + + [ContractClass(typeof(IErrorSinkContracts))] + public interface IErrorSink { + void Error(IToken/*!*/ tok, string/*!*/ msg); + } + [ContractClassFor(typeof(IErrorSink))] + public abstract class IErrorSinkContracts : IErrorSink { + #region IErrorSink Members + public void Error(IToken tok, string msg) { + Contract.Requires(tok != null); + Contract.Requires(msg != null); + throw new NotImplementedException(); + } + #endregion + } + + public class CheckingContext { + // ------------------------------ Error counting ------------------------------ + + IErrorSink errorSink; + int errors; + + public CheckingContext(IErrorSink errorSink) { + this.errorSink = errorSink; + } + + public int ErrorCount { + get { + return errors; + } + set { + errors = value; + } + } + + public void Error(Absy subject, string msg, params object[] args) { + Contract.Requires(args != null); + Contract.Requires(msg != null); + Contract.Requires(subject != null); + Error(subject.tok, msg, args); + } + + public virtual void Error(IToken tok, string msg) { + Contract.Requires(msg != null); + Contract.Requires(tok != null); + errors++; + if (errorSink == null) { + ConsoleColor col = Console.ForegroundColor; + Console.ForegroundColor = ConsoleColor.Red; + Console.WriteLine("{0}({1},{2}): Error: {3}", + tok.filename, tok.line, tok.col - 1, + msg); + Console.ForegroundColor = col; + } else { + errorSink.Error(tok, msg); + } + } + + private string Format(string msg, params object[] args) { + Contract.Requires(msg != null); + Contract.Ensures(Contract.Result<string>() != null); + if (System.Type.GetType("Mono.Runtime") != null) { // MONO + // something in mono seems to be broken so that calling + // NamedDeclarations.ToString (and similar ToString methods) + // causes a stack overflow. We therefore convert those to + // strings by hand + object[] fixedArgs = new object[cce.NonNull(args).Length]; + for (int i = 0; i < args.Length; ++i) { + if (args[i] is NamedDeclaration) { + fixedArgs[i] = cce.NonNull((NamedDeclaration)args[i]).Name; + } else if (args[i] is Type) { + System.IO.StringWriter buffer = new System.IO.StringWriter(); + using (TokenTextWriter stream = new TokenTextWriter("<buffer>", buffer, /*setTokens=*/ false, /*pretty=*/ false)) { + cce.NonNull((Type)args[i]).Emit(stream); + } + fixedArgs[i] = buffer.ToString(); + } else if (args[i] is Expr) { + System.IO.StringWriter buffer = new System.IO.StringWriter(); + using (TokenTextWriter stream = new TokenTextWriter("<buffer>", buffer, /*setTokens=*/ false, /*pretty=*/ false)) { + cce.NonNull((Expr/*!*/)args[i]).Emit(stream, 0, false); + } + fixedArgs[i] = buffer.ToString(); + } else { + fixedArgs[i] = args[i]; + } + } + args = fixedArgs; + } + return string.Format(msg, args); + } + + public void Error(IToken tok, string msg, params object[] args) { + Contract.Requires(msg != null); + Contract.Requires(tok != null); + Error(tok, Format(msg, args)); + } + + public void Warning(Absy subject, string msg, params object[] args) { + Contract.Requires(args != null); + Contract.Requires(msg != null); + Contract.Requires(subject != null); + Warning(subject.tok, msg, args); + } + + public virtual void Warning(IToken tok, string msg) { + Contract.Requires(msg != null); + Contract.Requires(tok != null); + // warnings are currently always written to the console + ConsoleColor col = Console.ForegroundColor; + Console.ForegroundColor = ConsoleColor.DarkYellow; + Console.WriteLine("{0}({1},{2}): Warning: {3}", + tok.filename, tok.line, tok.col - 1, + msg); + Console.ForegroundColor = col; + } + + public void Warning(IToken tok, string msg, params object[] args) { + Contract.Requires(msg != null); + Contract.Requires(tok != null); + Warning(tok, Format(msg, args)); + } + } + + public class ResolutionContext : CheckingContext { + public ResolutionContext(IErrorSink errorSink) + : base(errorSink) { + } + + // ------------------------------ Boogie 2 Types ------------------------- + + // user-defined types, which can be either TypeCtorDecl or TypeSynonymDecl + Hashtable /*string->NamedDeclaration*//*!*/ types = new Hashtable /*string->NamedDeclaration*/ (); + [ContractInvariantMethod] + void ObjectInvariant() { + Contract.Invariant(types != null); + Contract.Invariant(cce.NonNullElements(typeBinders)); + Contract.Invariant(varContext != null); + Contract.Invariant(funcdures != null); + } + + + /// <summary> + /// Checks if name coincides with the name of a bitvector type. If so, reports an error and + /// returns true; otherwise, returns false. + /// </summary> + private bool CheckBvNameClashes(Absy absy, string name) { + Contract.Requires(name != null); + Contract.Requires(absy != null); + if (name.StartsWith("bv") && name.Length > 2) { + for (int i = 2; i < name.Length; ++i) + if (!char.IsDigit(name[i])) + return false; + Error(absy, "type name: {0} is registered for bitvectors", name); + return true; + } + return false; + } + + public void AddType(NamedDeclaration td) { + Contract.Requires(td != null); + Contract.Requires((td is TypeCtorDecl) || (td is TypeSynonymDecl)); + Contract.Requires(td.Name != null); + + string name = td.Name; + if (CheckBvNameClashes(td, name)) + return; // error has already been reported + + var previous = (NamedDeclaration)types[name]; + if (previous == null) { + types.Add(name, td); + } else { + var r = (NamedDeclaration)SelectNonExtern(td, previous); + if (r == null) { + Error(td, "more than one declaration of type name: {0}", name); + } else { + types[name] = r; + } + } + } + + /// <summary> + /// Returns the declaration of the named type, or null if + /// no such type is declared. Also return null if the type + /// declared with the given name is not a constructor but a + /// type synonym + /// </summary> + /// <param name="name"></param> + /// <returns></returns> + public TypeCtorDecl LookUpType(string name) { + Contract.Requires(name != null); + return types[name] as TypeCtorDecl; + } + + public TypeSynonymDecl LookUpTypeSynonym(string name) { + Contract.Requires(name != null); + return types[name] as TypeSynonymDecl; + } + + // ------------------------------ Boogie 2 Type Binders ------------------------------ + + List<TypeVariable/*!*/>/*!*/ typeBinders = new List<TypeVariable/*!*/>(5); + + public void AddTypeBinder(TypeVariable td) { + Contract.Requires(td != null); + if (CheckBvNameClashes(td, td.Name)) { + return; + } + if (types.ContainsKey(td.Name)) { + Error(td, "name is already reserved for type constructor: {0}", td.Name); + return; + } + for (int i = 0; i < typeBinders.Count; i++) { + if (typeBinders[i].Name == td.Name) { + Error(td, "more than one declaration of type variable: {0}", td.Name); + return; + } + } + typeBinders.Add(td); + } + + public int TypeBinderState { + get { + return typeBinders.Count; + } + set { + typeBinders.RemoveRange(value, typeBinders.Count - value); + } + } + + /// <summary> + /// Returns the declaration of the named type binder, or null if + /// no such binder is declared. + /// </summary> + public TypeVariable LookUpTypeBinder(string name) { + Contract.Requires(name != null); + for (int i = typeBinders.Count; 0 <= --i; ) { + TypeVariable/*!*/ td = typeBinders[i]; + Contract.Assert(td != null); + if (td.Name == name) { + return td; + } + } + return null; // not present + } + + // ------------------------------ Variables ------------------------------ + + class VarContextNode { + [ContractInvariantMethod] + void ObjectInvariant() { + Contract.Invariant(VarSymbols != null); + } + + public readonly Hashtable /*string->Variable*//*!*/ VarSymbols = new Hashtable /*string->Variable*/(); + public /*maybe null*/ VarContextNode ParentContext; + public readonly bool Opaque; + readonly ISet<string> assignedAssumptionVariables = new HashSet<string>(); + + public bool HasVariableBeenAssigned(string name) + { + Contract.Requires(name != null); + + if (assignedAssumptionVariables.Contains(name)) + { + return true; + } + else if (ParentContext != null) + { + return ParentContext.HasVariableBeenAssigned(name); + } + else + { + return false; + } + } + + public bool MarkVariableAsAssigned(string name) + { + Contract.Requires(name != null); + + if (VarSymbols.Contains(name)) + { + if (assignedAssumptionVariables.Contains(name)) + { + return false; + } + assignedAssumptionVariables.Add(name); + return true; + } + else if (ParentContext != null) + { + return ParentContext.MarkVariableAsAssigned(name); + } + else + { + return false; + } + } + + public VarContextNode(/*maybe null*/ VarContextNode parentContext, bool opaque) { + ParentContext = parentContext; + Opaque = opaque; + } + } + + // symbolic constants, global variables, local variables, formals, expression-bound variables + VarContextNode/*!*/ varContext = new VarContextNode(null, false); + + /// <summary> + /// Adds a variable context. + /// </summary> + public void PushVarContext() { + varContext = new VarContextNode(varContext, false); + } + + /// <summary> + /// Adds an opaque variable context, that is, one that blocks all previously pushed contexts. + /// </summary> + public void PushOpaqueVarContext() { + varContext = new VarContextNode(varContext, true); + } + + /// <summary> + /// Requires there to be more than one variable context. + /// </summary> + public void PopVarContext() { + Contract.Assert(varContext.ParentContext != null); + varContext = varContext.ParentContext; + } + + public void AddVariable(Variable var, bool global) { + Contract.Requires(var != null); + var previous = FindVariable(cce.NonNull(var.Name), !global); + if (previous == null) { + varContext.VarSymbols.Add(var.Name, var); + } else { + var r = (Variable)SelectNonExtern(var, previous); + if (r == null) { + Error(var, "more than one declaration of variable name: {0}", var.Name); + } else { + varContext.VarSymbols[var.Name] = r; + } + } + } + + /// <summary> + /// Returns the declaration of the named variable, or null if + /// no such variable is declared. + /// </summary> + /// <param name="name"></param> + /// <returns></returns> + public Variable LookUpVariable(string name) { + Contract.Requires(name != null); + return FindVariable(name, false); + } + + Variable FindVariable(string name, bool ignoreTopLevelVars) { + Contract.Requires(name != null); + VarContextNode c = varContext; + bool lookOnlyForConstants = false; + do { + if (ignoreTopLevelVars && c.ParentContext == null) { + // this is the top level and we're asked to ignore the top level; hence, we're done + break; + } + + Variable var = (Variable)c.VarSymbols[name]; + if (var != null && (!lookOnlyForConstants || var is Constant)) { + return var; + } + // not at this level + + if (c.Opaque) { + // from here on, only constants can be looked up + lookOnlyForConstants = true; + } + c = c.ParentContext; + } while (c != null); + + // not present in the relevant levels + return null; + } + + public bool HasVariableBeenAssigned(string name) + { + Contract.Requires(name != null); + + return varContext.HasVariableBeenAssigned(name); + } + + public void MarkVariableAsAssigned(string name) + { + Contract.Requires(name != null); + + var success = varContext.MarkVariableAsAssigned(name); + Contract.Assume(success); + } + + Hashtable axioms = new Hashtable(); + + public void AddAxiom(Axiom axiom) { + string axiomName = QKeyValue.FindStringAttribute(axiom.Attributes, "name"); + if (axiomName == null) + return; + var previous = (Axiom)axioms[axiomName]; + if (previous == null) { + axioms.Add(axiomName, axiom); + } + else { + var r = (Axiom)SelectNonExtern(axiom, previous); + if (r == null) { + Error(axiom, "more than one declaration of axiom name: {0}", axiomName); + } + else { + axioms[axiomName] = r; + } + } + } + + // ------------------------------ Functions/Procedures ------------------------------ + + // uninterpreted function symbols, procedures + Hashtable /*string->DeclWithFormals*//*!*/ funcdures = new Hashtable /*string->DeclWithFormals*/ (); + + public void AddProcedure(DeclWithFormals proc) { + Contract.Requires(proc != null); + Contract.Requires(proc.Name != null); + + string name = proc.Name; + var previous = (DeclWithFormals)funcdures[name]; + if (previous == null) { + funcdures.Add(name, proc); + } else { + var r = (DeclWithFormals)SelectNonExtern(proc, previous); + if (r == null) { + Error(proc, "more than one declaration of function/procedure name: {0}", name); + } else { + funcdures[name] = r; + } + } + } + + /// <summary> + /// If both "a" and "b" have an ":extern" attribute, returns either one. + /// If one of "a" and "b" has an ":extern" attribute, returns that one. + /// If neither of "a" and "b" has an ":extern" attribute, returns null. + /// If a non-value value is returned, this method also adds the ":ignore" + /// attribute to the declaration NOT returned. + /// </summary> + Declaration SelectNonExtern(Declaration a, Declaration b) { + Contract.Requires(a != null); + Contract.Requires(b != null); + Contract.Ensures(Contract.Result<Declaration>() == null || Contract.Result<Declaration>() == a || Contract.Result<Declaration>() == b); + + Declaration ignore, keep; + if (QKeyValue.FindBoolAttribute(a.Attributes, "extern")) { + ignore = a; + keep = b; + } else if (QKeyValue.FindBoolAttribute(b.Attributes, "extern")) { + ignore = b; + keep = a; + } else { + return null; + } + // prepend :ignore attribute + ignore.Attributes = new QKeyValue(ignore.tok, "ignore", new List<object/*!*/>(), ignore.Attributes); + return keep; + } + + /// <summary> + /// Returns the declaration of the named function/procedure, or null if + /// no such function or procedure is declared. + /// </summary> + /// <param name="name"></param> + /// <returns></returns> + public DeclWithFormals LookUpProcedure(string name) { + Contract.Requires(name != null); + return (DeclWithFormals)funcdures[name]; + } + + // ------------------------------ Blocks ------------------------------ + + class ProcedureContext { + [ContractInvariantMethod] + void ObjectInvariant() { + Contract.Invariant(Blocks != null); + } + + public readonly Hashtable/*!*/ /*string->Block!*/ Blocks; + public readonly ProcedureContext Next; + public ProcedureContext(ProcedureContext next) { + Blocks = new Hashtable /*string->Block!*/ (); + Next = next; + } + } + /*maybe null*/ + ProcedureContext procedureContext; // stack of procedure contexts + public bool HasProcedureContext { + get { + return procedureContext != null; + } + } + + /// <summary> + /// Pushes a new procedure context. + /// </summary> + public void PushProcedureContext() { + Contract.Ensures(HasProcedureContext); + procedureContext = new ProcedureContext(procedureContext); + } + + /// <summary> + /// Requires there to be a procedure context. Pops it. + /// </summary> + public void PopProcedureContext() { + Contract.Requires(HasProcedureContext); + Contract.Assert(procedureContext != null); // follows from precondition + procedureContext = procedureContext.Next; + } + + /// <summary> + /// Requires there to be a procedure context. + /// </summary> + /// <param name="block"></param> + public void AddBlock(Block block) { + Contract.Requires(block != null); + Contract.Requires(HasProcedureContext); + Contract.Assert(procedureContext != null); // follows from precondition + Hashtable/*!*/ /*string->Block!*/ blocks = procedureContext.Blocks; + Contract.Assert(blocks != null); + if (blocks[block.Label] != null) { + Error(block, "more than one declaration of block name: {0}", block.Label); + } else { + blocks.Add(block.Label, block); + } + } + + /// <summary> + /// Requires there to be a procedure context. + /// Returns the declaration of the named block, or null if + /// no such block is declared. + /// </summary> + /// <param name="name"></param> + /// <returns></returns> + public Block LookUpBlock(string name) { + Contract.Requires(name != null); + Contract.Requires(HasProcedureContext); + Contract.Assert(procedureContext != null); // follows from precondition + Hashtable/*!*/ /*string->Block!*/ blocks = procedureContext.Blocks; + Contract.Assert(blocks != null); + return (Block)blocks[name]; + } + + // ------------------------------ Flags ------------------------------ + + public enum State { + StateLess, + Single, + Two + } + State stateMode = State.Single; + + /// <summary> + /// To increase our confidence in that the caller knows what it's doing, we only allow + /// the state mode to be changed in and out of the State.Single mode. + /// </summary> + public State StateMode { + get { + return stateMode; + } + set { + Contract.Assert(value != stateMode); + Contract.Assert(stateMode == State.Single || value == State.Single); + cce.BeginExpose(this); + { + stateMode = value; + } + cce.EndExpose(); + } + } + + bool triggerMode = false; + + /// <summary> + /// Setting TriggerMode is allowed only if the setting has the effect of toggling the + /// boolean. That is, TriggerMode can be set to true only if it previously was false, + /// and TriggerMode can be set to false only if it previously was true. + /// </summary> + public bool TriggerMode { + get { + return triggerMode; + } + set { + Contract.Assert(triggerMode != value); + cce.BeginExpose(this); + { + triggerMode = value; + } + cce.EndExpose(); + } + } + } + + public class TypecheckingContext : CheckingContext { + public List<IdentifierExpr> Frame; // used in checking the assignment targets of implementation bodies + public bool Yields; + + public TypecheckingContext(IErrorSink errorSink) + : base(errorSink) { + } + + public bool InFrame(Variable v) { + Contract.Requires(v != null); + Contract.Requires(Frame != null); + return Frame.Any(f => f.Decl == v); + } + } +} |