source: branches/RemoveBackwardsCompatibility/HeuristicLab.ExtLibs/HeuristicLab.NRefactory/5.5.0/NRefactory-5.5.0/Analysis/AbiComparer.cs @ 14861

//
// ABIComparer.cs
//
// Author:
//       Mike KrÃŒger <mkrueger@xamarin.com>
//
// Copyright (c) 2013 Xamarin Inc. (http://xamarin.com)
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.
using System;
using ICSharpCode.NRefactory.TypeSystem;
using System.Collections.Generic;
using System.Linq;

namespace ICSharpCode.NRefactory.Analysis
{
  /// <summary>
  /// Used to check the compatibility state of two compilations.
  /// </summary>
  public enum AbiCompatibility
  {
    /// <summary>
    /// The ABI is equal
    /// </summary>
    Equal,

    /// <summary>
    /// Some items got added, but the ABI remains to be compatible
    /// </summary>
    Bigger,

    /// <summary>
    /// The ABI has changed
    /// </summary>
    Incompatible
  }

  [Serializable]
  public sealed class AbiEventArgs : EventArgs
  {
    public string Message { get; set; }

    public AbiEventArgs(string message)
    {
      this.Message = message;
    }
  }

  /// <summary>
  /// The Abi comparer checks the public API of two compilation and determines the compatibility state.
  /// </summary>
  public class AbiComparer
  {
    public bool StopOnIncompatibility {
      get; 
      set;
    }
    void CheckContstraints(IType otype, ITypeParameter p1, ITypeParameter p2, ref AbiCompatibility compatibility)
    {
      if (p1.DirectBaseTypes.Count () != p2.DirectBaseTypes.Count () ||
          p1.HasReferenceTypeConstraint != p2.HasReferenceTypeConstraint ||
          p1.HasValueTypeConstraint != p2.HasValueTypeConstraint ||
          p1.HasDefaultConstructorConstraint != p2.HasDefaultConstructorConstraint) {
        OnIncompatibilityFound (new AbiEventArgs (string.Format (TranslateString ("Type parameter constraints of type {0} have changed."), otype.FullName)));
        compatibility = AbiCompatibility.Incompatible;
      }
    }

    void CheckContstraints(IMethod omethod, ITypeParameter p1, ITypeParameter p2, ref AbiCompatibility compatibility)
    {
      if (p1.DirectBaseTypes.Count () != p2.DirectBaseTypes.Count () ||
          p1.HasReferenceTypeConstraint != p2.HasReferenceTypeConstraint ||
          p1.HasValueTypeConstraint != p2.HasValueTypeConstraint ||
          p1.HasDefaultConstructorConstraint != p2.HasDefaultConstructorConstraint) {
        OnIncompatibilityFound (new AbiEventArgs (string.Format (TranslateString ("Type parameter constraints of method {0} have changed."), omethod.FullName)));
        compatibility = AbiCompatibility.Incompatible;
      }
    }

    void CheckTypes (ITypeDefinition oType, ITypeDefinition nType, ref AbiCompatibility compatibility)
    {
      int oldMemberCount = 0;
      Predicate<IUnresolvedMember> pred = null;
      if (oType.Kind == TypeKind.Class || oType.Kind == TypeKind.Struct)
        pred = m => (m.IsPublic || m.IsProtected) && !m.IsOverride && !m.IsSynthetic;

      for (int i = 0; i < oType.TypeParameterCount; i++) {
        CheckContstraints (oType, oType.TypeParameters[i], nType.TypeParameters[i], ref compatibility);
        if (compatibility == AbiCompatibility.Incompatible && StopOnIncompatibility)
          return;
      }

      foreach (var member in oType.GetMembers (pred, GetMemberOptions.IgnoreInheritedMembers)) {
        var newMember = nType.GetMembers (m => member.UnresolvedMember.Name == m.Name && m.IsPublic == member.IsPublic && m.IsProtected == member.IsProtected);
        var equalMember = newMember.FirstOrDefault (m => SignatureComparer.Ordinal.Equals (member, m));
        if (equalMember == null) {
          compatibility = AbiCompatibility.Incompatible;
          if (StopOnIncompatibility)
            return;
          continue;
        }
        var om = member as IMethod;
        if (om != null) {
          for (int i = 0; i < om.TypeParameters.Count; i++) {
            CheckContstraints (om, om.TypeParameters[i], ((IMethod)equalMember).TypeParameters[i], ref compatibility);
            if (compatibility == AbiCompatibility.Incompatible && StopOnIncompatibility)
              return;
          }
        }

        oldMemberCount++;
      }
      if (compatibility == AbiCompatibility.Bigger && oType.Kind != TypeKind.Interface)
        return;
      if (oldMemberCount != nType.GetMembers (pred, GetMemberOptions.IgnoreInheritedMembers).Count ()) {
        if (oType.Kind == TypeKind.Interface) {
          OnIncompatibilityFound (new AbiEventArgs (string.Format (TranslateString ("Interafce {0} has changed."), oType.FullName)));
          compatibility = AbiCompatibility.Incompatible;
        } else {
          if (compatibility == AbiCompatibility.Equal)
            compatibility = AbiCompatibility.Bigger;
        }
      }
    }

    void CheckNamespace(INamespace oNs, INamespace nNs, ref AbiCompatibility compatibility)
    {
      foreach (var type in oNs.Types) {
        if (!type.IsPublic && !type.IsProtected)
          continue;
        var newType = nNs.GetTypeDefinition (type.Name, type.TypeParameterCount);
        if (newType == null) {
          OnIncompatibilityFound (new AbiEventArgs (string.Format (TranslateString ("Type definition {0} is missing."), type.FullName)));
          compatibility = AbiCompatibility.Incompatible;
          if (StopOnIncompatibility) 
            return;
          continue;
        }
        CheckTypes (type, newType, ref compatibility);
        if (compatibility == AbiCompatibility.Incompatible && StopOnIncompatibility)
          return;
      }

      if (compatibility == AbiCompatibility.Bigger)
        return;
      foreach (var type in nNs.Types) {
        if (!type.IsPublic && !type.IsProtected)
          continue;
        if (oNs.GetTypeDefinition (type.Name, type.TypeParameterCount) == null) {
          if (compatibility == AbiCompatibility.Equal)
            compatibility = AbiCompatibility.Bigger;
          return;
        }
      }
    }

    static bool ContainsPublicTypes(INamespace testNs)
    {
      var stack = new Stack<INamespace> ();
      stack.Push (testNs);
      while (stack.Count > 0) {
        var ns = stack.Pop ();
        if (ns.Types.Any (t => t.IsPublic))
          return true;
        foreach (var child in ns.ChildNamespaces)
          stack.Push (child);
      }
      return false;
    }

    /// <summary>
    /// Check the specified oldProject and newProject if they're compatible.
    /// </summary>
    /// <param name="oldProject">Old project.</param>
    /// <param name="newProject">New project.</param>
    public AbiCompatibility Check (ICompilation oldProject, ICompilation newProject)
    {
      var oldStack = new Stack<INamespace> ();
      var newStack = new Stack<INamespace> ();
      oldStack.Push (oldProject.MainAssembly.RootNamespace);
      newStack.Push (newProject.MainAssembly.RootNamespace);

      AbiCompatibility compatibility = AbiCompatibility.Equal;
      while (oldStack.Count > 0) {
        var oNs = oldStack.Pop ();
        var nNs = newStack.Pop ();

        CheckNamespace (oNs, nNs, ref compatibility);
        if (compatibility == AbiCompatibility.Incompatible && StopOnIncompatibility)
          return AbiCompatibility.Incompatible;
        foreach (var child in oNs.ChildNamespaces) {
          var newChild = nNs.GetChildNamespace (child.Name);
          if (newChild == null) {
            OnIncompatibilityFound (new AbiEventArgs (string.Format (TranslateString ("Namespace {0} is missing."), child.FullName)));
            if (StopOnIncompatibility)
              return AbiCompatibility.Incompatible;
            continue;
          }
          oldStack.Push (child);
          newStack.Push (newChild);
        }

        // check if namespaces are added
        if (compatibility != AbiCompatibility.Bigger) {
          foreach (var child in nNs.ChildNamespaces) {
            if (oNs.GetChildNamespace (child.Name) == null) {
              if (compatibility == AbiCompatibility.Equal && ContainsPublicTypes (child))
                compatibility = AbiCompatibility.Bigger;
              break;
            }
          }
        }
      }
      return compatibility;
    }

    public virtual string TranslateString(string str)
    {
      return str;
    }

    public event EventHandler<AbiEventArgs> IncompatibilityFound;

    protected virtual void OnIncompatibilityFound(AbiEventArgs e)
    {
      var handler = IncompatibilityFound;
      if (handler != null)
        handler(this, e);
    }
  }
}