change error flow

src/Workspaces/Core/Desktop/PublicAPI.Unshipped.txt

+Microsoft.CodeAnalysis.MSBuild.MSBuildWorkspace.Diagnostics.get -> System.Collections.Immutable.ImmutableList<Microsoft.CodeAnalysis.WorkspaceDiagnostic>
\ No newline at end of file

src/Workspaces/Core/Desktop/Workspace/MSBuild/CSharp/CSharpProjectFileLoader.CSharpProjectFile.cs

@@ -23,8 +23,8 @@ internal partial class CSharpProjectFileLoader : ProjectFileLoader
     {
         private class CSharpProjectFile : ProjectFile
         {
-            public CSharpProjectFile(CSharpProjectFileLoader loader, MSB.Evaluation.Project project, Exception loadException)
-                : base(loader, project, loadException)
+            public CSharpProjectFile(CSharpProjectFileLoader loader, MSB.Evaluation.Project project, string errorMessage)
+                : base(loader, project, errorMessage)
             {
             }
 
@@ -98,7 +98,7 @@ private ProjectFileInfo CreateProjectFileInfo(CSharpCompilerInputs compilerInput
                         docs,
                         additionalDocs,
                         this.GetProjectReferences(buildInfo.Project),
-                        buildInfo.Exception);
+                        buildInfo.ErrorMessage);
                 }
                 else
                 {
@@ -109,7 +109,7 @@ private ProjectFileInfo CreateProjectFileInfo(CSharpCompilerInputs compilerInput
                         documents: SpecializedCollections.EmptyEnumerable<DocumentFileInfo>(),
                         additionalDocuments: SpecializedCollections.EmptyEnumerable<DocumentFileInfo>(),
                         projectReferences: SpecializedCollections.EmptyEnumerable<ProjectFileReference>(),
-                        buildException: buildInfo.Exception);
+                        errorMessage: buildInfo.ErrorMessage);
                 }
             }
 

src/Workspaces/Core/Desktop/Workspace/MSBuild/CSharp/CSharpProjectFileLoader.cs

@@ -22,7 +22,7 @@ public override string Language
 
         protected override ProjectFile CreateProjectFile(LoadedProjectInfo info)
         {
-            return new CSharpProjectFile(this, info.Project, info.Exception);
+            return new CSharpProjectFile(this, info.Project, info.ErrorMessage);
         }
     }
 }

src/Workspaces/Core/Desktop/Workspace/MSBuild/MSBuildProjectLoader.cs

@@ -157,7 +157,7 @@ private void SetSolutionProperties(string solutionFilePath)
                         {
                             // projects get added to 'loadedProjects' as side-effect
                             // never prefer metadata when loading solution, all projects get loaded if they can.
-                            var tmp = await GetOrLoadProjectAsync(projectAbsolutePath, loader, preferMetadata: false, reportBuildFailures: ReportMode.Log, loadedProjects: loadedProjects, cancellationToken: cancellationToken).ConfigureAwait(false);
+                            var tmp = await GetOrLoadProjectAsync(projectAbsolutePath, loader, preferMetadata: false, loadedProjects: loadedProjects, cancellationToken: cancellationToken).ConfigureAwait(false);
                         }
                     }
                 }
@@ -210,7 +210,7 @@ internal string GetAbsoluteSolutionPath(string path, string baseDirectory)
 
             var loadedProjects = new LoadState(projectPathToProjectIdMap);
 
-            var id = await this.LoadProjectAsync(fullPath, loader, this.LoadMetadataForReferencedProjects, ReportMode.Log, loadedProjects, cancellationToken).ConfigureAwait(false);
+            var id = await this.LoadProjectAsync(fullPath, loader, this.LoadMetadataForReferencedProjects, loadedProjects, cancellationToken).ConfigureAwait(false);
 
             var result = loadedProjects.Projects.Reverse().ToImmutableArray();
             Debug.Assert(result[0].Id == id);
@@ -304,18 +304,18 @@ public ProjectId GetOrCreateProjectId(string fullProjectPath)
             }
         }
 
-        private async Task<ProjectId> GetOrLoadProjectAsync(string projectFilePath, IProjectFileLoader loader, bool preferMetadata, ReportMode reportBuildFailures, LoadState loadedProjects, CancellationToken cancellationToken)
+        private async Task<ProjectId> GetOrLoadProjectAsync(string projectFilePath, IProjectFileLoader loader, bool preferMetadata, LoadState loadedProjects, CancellationToken cancellationToken)
         {
             var projectId = loadedProjects.GetProjectId(projectFilePath);
             if (projectId == null)
             {
-                projectId = await this.LoadProjectAsync(projectFilePath, loader, preferMetadata, reportBuildFailures, loadedProjects, cancellationToken).ConfigureAwait(false);
+                projectId = await this.LoadProjectAsync(projectFilePath, loader, preferMetadata, loadedProjects, cancellationToken).ConfigureAwait(false);
             }
 
             return projectId;
         }
 
-        private async Task<ProjectId> LoadProjectAsync(string projectFilePath, IProjectFileLoader loader, bool preferMetadata, ReportMode reportBuildFailures, LoadState loadedProjects, CancellationToken cancellationToken)
+        private async Task<ProjectId> LoadProjectAsync(string projectFilePath, IProjectFileLoader loader, bool preferMetadata, LoadState loadedProjects, CancellationToken cancellationToken)
         {
             Debug.Assert(projectFilePath != null);
             Debug.Assert(loader != null);
@@ -324,19 +324,19 @@ private async Task<ProjectId> LoadProjectAsync(string projectFilePath, IProjectF
             var projectName = Path.GetFileNameWithoutExtension(projectFilePath);
 
             var projectFile = await loader.LoadProjectFileAsync(projectFilePath, _properties, cancellationToken).ConfigureAwait(false);
-            if (projectFile.LoadException != null)
+            if (projectFile.ErrorMessage != null)
             {
-                ReportFailure(reportBuildFailures, string.Format(WorkspaceDesktopResources.Cannot_open_project_0_because_msbuild_failed_with_message_1, projectFilePath, projectFile.LoadException.Message));
+                ReportFailure(ReportMode.Log, GetMsbuildFailedMessage(projectFilePath, projectFile.ErrorMessage));
+
+                // if we failed during load there won't be any project file info, so bail early with empty project.
                 loadedProjects.Add(CreateEmptyProjectInfo(projectId, projectFilePath, loader.Language));
                 return projectId;
             }
 
             var projectFileInfo = await projectFile.GetProjectFileInfoAsync(cancellationToken).ConfigureAwait(false);
-            if (projectFileInfo.BuildException != null)
+            if (projectFileInfo.ErrorMessage != null)
             {
-                ReportFailure(reportBuildFailures, string.Format(WorkspaceDesktopResources.Cannot_open_project_0_because_msbuild_failed_with_message_1, projectFilePath, projectFileInfo.BuildException.Message));
-                loadedProjects.Add(CreateEmptyProjectInfo(projectId, projectFilePath, loader.Language));
-                return projectId;
+                ReportFailure(ReportMode.Log, GetMsbuildFailedMessage(projectFilePath, projectFileInfo.ErrorMessage));
             }
 
             var projectDirectory = Path.GetDirectoryName(projectFilePath);
@@ -464,6 +464,18 @@ private async Task<ProjectId> LoadProjectAsync(string projectFilePath, IProjectF
             return projectId;
         }
 
+        private static string GetMsbuildFailedMessage(string projectFilePath, string message)
+        {
+            if (string.IsNullOrWhiteSpace(message))
+            {
+                return string.Format(WorkspaceDesktopResources.Msbuild_failed_when_processing_the_file_0, projectFilePath);
+            }
+            else
+            {
+                return string.Format(WorkspaceDesktopResources.Msbuild_failed_when_processing_the_file_0_with_message_1, projectFilePath, message);
+            }
+        }
+
         private static VersionStamp GetProjectVersion(string projectFilePath)
         {
             if (!string.IsNullOrEmpty(projectFilePath) && File.Exists(projectFilePath))
@@ -604,7 +616,7 @@ private class ResolvedReferences
                     if (TryGetLoaderFromProjectPath(fullPath, reportMode, out loader))
                     {
                         // load the project
-                        var projectId = await this.GetOrLoadProjectAsync(fullPath, loader, preferMetadata, ReportMode.Log, loadedProjects, cancellationToken).ConfigureAwait(false);
+                        var projectId = await this.GetOrLoadProjectAsync(fullPath, loader, preferMetadata, loadedProjects, cancellationToken).ConfigureAwait(false);
 
                         // If that other project already has a reference on us, this will cause a circularity.
                         // This check doesn't need to be in the "already loaded" path above, since in any circularity this path

src/Workspaces/Core/Desktop/Workspace/MSBuild/MSBuildWorkspace.cs

@@ -30,6 +30,7 @@ public sealed class MSBuildWorkspace : Workspace
         private readonly NonReentrantLock _serializationLock = new NonReentrantLock();
 
         private MSBuildProjectLoader _loader;
+        private ImmutableList<WorkspaceDiagnostic> _diagnostics = ImmutableList<WorkspaceDiagnostic>.Empty;
 
         private MSBuildWorkspace(
             HostServices hostServices,
@@ -96,6 +97,20 @@ public static MSBuildWorkspace Create(IDictionary<string, string> properties, Ho
             get { return _loader.Properties; }
         }
 
+        /// <summary>
+        /// Diagnostics logged while opening solutions, projects and documents.
+        /// </summary>
+        public ImmutableList<WorkspaceDiagnostic> Diagnostics
+        {
+            get { return _diagnostics; }
+        }
+
+        protected internal override void OnWorkspaceFailed(WorkspaceDiagnostic diagnostic)
+        {
+            ImmutableInterlocked.Update(ref _diagnostics, d => d.Add(diagnostic));
+            base.OnWorkspaceFailed(diagnostic);
+        }
+
         /// <summary>
         /// Determines if metadata from existing output assemblies is loaded instead of opening referenced projects.
         /// If the referenced project is already opened, the metadata will not be loaded.

src/Workspaces/Core/Desktop/Workspace/MSBuild/ProjectFile/BuildTargets.cs

-// Copyright (c) Microsoft.  All Rights Reserved.  Licensed under the Apache License, Version 2.0.  See License.txt in the project root for license information.
-
-using System;
-using System.Collections.Generic;
-using System.IO;
-using System.Linq;
-using System.Threading;
-using Microsoft.CodeAnalysis;
-using Microsoft.CodeAnalysis.Text;
-using Roslyn.Utilities;
-using MSB = Microsoft.Build;
-
-namespace Microsoft.CodeAnalysis.MSBuild
-{
-    /// <summary>
-    /// Defines a list of build targets and operations to modify that list.
-    /// </summary>
-    internal class BuildTargets
-    {
-        private readonly MSB.Evaluation.Project _project;
-        private readonly List<string> _buildTargets;
-
-        public BuildTargets(MSB.Evaluation.Project project, params string[] targets)
-        {
-            _project = project;
-            _buildTargets = new List<string>();
-            _buildTargets.AddRange(targets);
-        }
-
-        public string[] Targets
-        {
-            get { return _buildTargets.ToArray(); }
-        }
-
-        /// <summary>
-        /// Remove the specified target from the build targets. 
-        /// 
-        /// If the target is nested (a dependent target) of one of the build targets, 
-        /// promote the siblings of the target to the formal list (in execution order.)
-        /// </summary>
-        public void Remove(string target)
-        {
-            // keep a set of targets already known to be in the build target list so we can keep
-            // from redundantly adding multiple of the same targets when we replace a target with
-            // its children
-            var knownTargets = new HashSet<string>();
-
-            for (int i = 0; i < _buildTargets.Count;)
-            {
-                var buildTarget = _buildTargets[i];
-                if (buildTarget == target)
-                {
-                    // we found it!
-                    _buildTargets.RemoveAt(i);
-
-                    // it might exist multiple times
-                    continue;
-                }
-                else if (DependsOn(buildTarget, target))
-                {
-                    // replace this build target with its children and check again
-                    _buildTargets.RemoveAt(i);
-
-                    int loc = i;
-                    foreach (var dependsOnTarget in GetTargetDependents(_project, buildTarget))
-                    {
-                        if (!knownTargets.Contains(dependsOnTarget))
-                        {
-                            _buildTargets.Insert(loc, dependsOnTarget);
-                            loc++;
-                        }
-                    }
-
-                    continue;
-                }
-                else
-                {
-                    knownTargets.Add(buildTarget);
-                    i++;
-                }
-            }
-        }
-
-        /// <summary>
-        /// Remove all targets after the specified target (and possibly also remove the specified target).
-        /// 
-        /// If a removed target is nested (a dependent target) of one of the build targets, 
-        /// promote the siblings of the removed target to the formal list (in execution order).
-        /// </summary>
-        public void RemoveAfter(string target, bool includeTargetInRemoval)
-        {
-            // keep a set of targets already known to be in the build target list
-            // so we can keep from redundantly adding multiple of the same targets
-            // when we replace a target with its children
-            var knownTargets = new HashSet<string>();
-
-            bool found = false;
-
-            for (int i = 0; i < _buildTargets.Count;)
-            {
-                var buildTarget = _buildTargets[i];
-                if (found)
-                {
-                    _buildTargets.RemoveAt(i);
-                    continue;
-                }
-                else if (buildTarget == target)
-                {
-                    // we found it!
-                    found = true;
-                    if (!includeTargetInRemoval)
-                    {
-                        i++;
-                    }
-                }
-                else if (DependsOn(buildTarget, target))
-                {
-                    // replace this build target with its children and check again
-                    _buildTargets.RemoveAt(i);
-
-                    int loc = i;
-                    foreach (var dependsOnTarget in GetTargetDependents(_project, buildTarget))
-                    {
-                        if (!knownTargets.Contains(dependsOnTarget))
-                        {
-                            _buildTargets.Insert(loc, dependsOnTarget);
-                            loc++;
-                        }
-                    }
-
-                    continue;
-                }
-                else
-                {
-                    knownTargets.Add(buildTarget);
-                    i++;
-                }
-            }
-        }
-
-        private bool DependsOn(string target, string dependentTarget)
-        {
-            foreach (var dependsOnTarget in GetTargetDependents(_project, target))
-            {
-                if (dependsOnTarget == dependentTarget || DependsOn(dependsOnTarget, dependentTarget))
-                {
-                    return true;
-                }
-            }
-
-            return false;
-        }
-
-        private static readonly char[] s_targetsSplitChars = new char[] { ';', '\r', '\n', '\t', ' ' };
-
-        private static IEnumerable<string> SplitTargets(string targets)
-        {
-            return targets.Split(s_targetsSplitChars, StringSplitOptions.RemoveEmptyEntries);
-        }
-
-        private static IEnumerable<string> GetTargetDependents(MSB.Evaluation.Project project, string targetName)
-        {
-            MSB.Execution.ProjectTargetInstance targetInstance;
-            if (project.Targets.TryGetValue(targetName, out targetInstance))
-            {
-                return SplitTargets(project.ExpandString(targetInstance.DependsOnTargets));
-            }
-            else
-            {
-                return SpecializedCollections.EmptyEnumerable<string>();
-            }
-        }
-
-        internal static IEnumerable<string> GetTopLevelTargets(MSB.Evaluation.Project project)
-        {
-            // start with set of all targets
-            HashSet<string> targets = new HashSet<string>(project.Targets.Keys);
-
-            // remove any target that another target depends on
-            foreach (var target in project.Targets.Keys)
-            {
-                var dependents = GetTargetDependents(project, target).ToList();
-                foreach (var depTarget in dependents)
-                {
-                    targets.Remove(depTarget);
-                }
-            }
-
-            return targets;
-        }
-    }
-}

src/Workspaces/Core/Desktop/Workspace/MSBuild/ProjectFile/IProjectFile.cs

@@ -21,9 +21,10 @@ internal interface IProjectFile
         string FilePath { get; }
 
         /// <summary>
-        /// Exception thrown attempting to load the project.
+        /// The error message produced when a failure occurred attempting to access the project file. 
+        /// If a failure occurred the projectd file info will be inaccessible.
         /// </summary>
-        Exception LoadException { get; }
+        string ErrorMessage { get; }
 
         /// <summary>
         /// Gets the project file info asynchronously.

src/Workspaces/Core/Desktop/Workspace/MSBuild/ProjectFile/ProjectFile.cs

@@ -19,13 +19,13 @@ internal abstract class ProjectFile : IProjectFile
     {
         private readonly ProjectFileLoader _loader;
         private readonly MSB.Evaluation.Project _loadedProject;
-        private readonly Exception _loadException;
+        private readonly string _errorMessage;
 
-        public ProjectFile(ProjectFileLoader loader, MSB.Evaluation.Project loadedProject, Exception loadException)
+        public ProjectFile(ProjectFileLoader loader, MSB.Evaluation.Project loadedProject, string errorMessage)
         {
             _loader = loader;
             _loadedProject = loadedProject;
-            _loadException = loadException;
+            _errorMessage = errorMessage;
         }
 
         ~ProjectFile()
@@ -45,9 +45,9 @@ public virtual string FilePath
             get { return _loadedProject.FullPath; }
         }
 
-        public Exception LoadException
+        public string ErrorMessage
         {
-            get { return _loadException; }
+            get { return _errorMessage; }
         }
 
         public string GetPropertyValue(string name)
@@ -62,24 +62,17 @@ public string GetPropertyValue(string name)
         public struct BuildInfo
         {
             public readonly ProjectInstance Project;
-            public readonly Exception Exception;
+            public readonly string ErrorMessage;
 
-            public BuildInfo(ProjectInstance project, Exception exception)
+            public BuildInfo(ProjectInstance project, string errorMessage)
             {
                 this.Project = project;
-                this.Exception = exception;
+                this.ErrorMessage = errorMessage;
             }
         }
 
         protected async Task<BuildInfo> BuildAsync(string taskName, MSB.Framework.ITaskHost taskHost, CancellationToken cancellationToken)
         {
-            // prepare for building
-            var buildTargets = new BuildTargets(_loadedProject, "Compile");
-
-            // don't execute anything after CoreCompile target, since we've
-            // already done everything we need to compute compiler inputs by then.
-            buildTargets.RemoveAfter("CoreCompile", includeTargetInRemoval: false);
-
             // create a project instance to be executed by build engine.
             // The executed project will hold the final model of the project after execution via msbuild.
             var executedProject = _loadedProject.CreateProjectInstance();
@@ -94,19 +87,19 @@ protected async Task<BuildInfo> BuildAsync(string taskName, MSB.Framework.ITaskH
             // connect the host "callback" object with the host services, so we get called back with the exact inputs to the compiler task.
             hostServices.RegisterHostObject(_loadedProject.FullPath, "CoreCompile", taskName, taskHost);
 
-            try
-            {
-                var buildParameters = new MSB.Execution.BuildParameters(_loadedProject.ProjectCollection);
+            var buildParameters = new MSB.Execution.BuildParameters(_loadedProject.ProjectCollection);
 
-                var buildRequestData = new MSB.Execution.BuildRequestData(executedProject, buildTargets.Targets, hostServices);
+            var buildRequestData = new MSB.Execution.BuildRequestData(executedProject, new string[] { "Compile" }, hostServices);
 
-                var result = await this.BuildAsync(buildParameters, buildRequestData, cancellationToken).ConfigureAwait(continueOnCapturedContext: false);
+            BuildResult result = await this.BuildAsync(buildParameters, buildRequestData, cancellationToken).ConfigureAwait(continueOnCapturedContext: false);
 
-                return new BuildInfo(executedProject, result.Exception);
+            if (result.OverallResult == BuildResultCode.Failure)
+            {
+                return new BuildInfo(executedProject, result.Exception?.Message ?? "");
             }
-            catch (Exception e)
+            else
             {
-                return new BuildInfo(project: null, exception: e);
+                return new BuildInfo(executedProject, null);
             }
         }
 

src/Workspaces/Core/Desktop/Workspace/MSBuild/ProjectFile/ProjectFileInfo.cs

@@ -43,9 +43,10 @@ internal sealed class ProjectFileInfo
         public IReadOnlyList<ProjectFileReference> ProjectReferences { get; }
 
         /// <summary>
-        /// An exception produced by the build system.
+        /// The error message produced when a failure occurred attempting to get the info. 
+        /// If a failure occurred some or all of the information may be inaccurate or incomplete.
         /// </summary>
-        public Exception BuildException { get; }
+        public string ErrorMessage { get; }
 
         public ProjectFileInfo(
             string outputPath,
@@ -54,7 +55,7 @@ internal sealed class ProjectFileInfo
             IEnumerable<DocumentFileInfo> documents,
             IEnumerable<DocumentFileInfo> additionalDocuments,
             IEnumerable<ProjectFileReference> projectReferences,
-            Exception buildException)
+            string errorMessage)
         {
             this.OutputFilePath = outputPath;
             this.AssemblyName = assemblyName;
@@ -62,7 +63,7 @@ internal sealed class ProjectFileInfo
             this.Documents = documents.ToImmutableReadOnlyListOrEmpty();
             this.AdditionalDocuments = additionalDocuments.ToImmutableArrayOrEmpty();
             this.ProjectReferences = projectReferences.ToImmutableReadOnlyListOrEmpty();
-            this.BuildException = buildException;
+            this.ErrorMessage = errorMessage;
         }
     }
 }

src/Workspaces/Core/Desktop/Workspace/MSBuild/ProjectFile/ProjectFileLoader.cs

@@ -42,12 +42,12 @@ public async Task<IProjectFile> LoadProjectFileAsync(string path, IDictionary<st
         public struct LoadedProjectInfo
         {
             public readonly MSB.Evaluation.Project Project;
-            public readonly Exception Exception;
+            public readonly string ErrorMessage;
 
-            public LoadedProjectInfo(MSB.Evaluation.Project project, Exception exception)
+            public LoadedProjectInfo(MSB.Evaluation.Project project, string errorMessage)
             {
                 this.Project = project;
-                this.Exception = exception;
+                this.ErrorMessage = errorMessage;
             }
         }
 
@@ -69,11 +69,11 @@ private static async Task<LoadedProjectInfo> LoadProjectAsync(string path, IDict
 
                 return new LoadedProjectInfo(
                     new MSB.Evaluation.Project(xml, properties, toolsVersion: null, projectCollection: collection),
-                    exception: null);
+                    errorMessage: null);
             }
             catch (Exception e)
             {
-                return new LoadedProjectInfo(project: null, exception: e);
+                return new LoadedProjectInfo(project: null, errorMessage: e.Message);
             }
         }
 

src/Workspaces/Core/Desktop/Workspace/MSBuild/VisualBasic/VisualBasicProjectFileLoader.cs

@@ -35,13 +35,13 @@ internal VisualBasicProjectFileLoader()
 
         protected override ProjectFile CreateProjectFile(LoadedProjectInfo info)
         {
-            return new VisualBasicProjectFile(this, info.Project, info.Exception);
+            return new VisualBasicProjectFile(this, info.Project, info.ErrorMessage);
         }
 
         internal class VisualBasicProjectFile : ProjectFile
         {
-            public VisualBasicProjectFile(VisualBasicProjectFileLoader loader, MSB.Evaluation.Project loadedProject, Exception loadException) 
-                : base(loader, loadedProject, loadException)
+            public VisualBasicProjectFile(VisualBasicProjectFileLoader loader, MSB.Evaluation.Project loadedProject, string errorMessage) 
+                : base(loader, loadedProject, errorMessage)
             {
             }
 
@@ -89,7 +89,7 @@ private ProjectFileInfo CreateProjectFileInfo(VisualBasicProjectFileLoader.Visua
                     documents,
                     additionalDocuments,
                     projectRefeferences,
-                    buildInfo.Exception);
+                    buildInfo.ErrorMessage);
             }
 
             private IEnumerable<DocumentFileInfo> GetDocuments(IEnumerable<ITaskItem> sources, ProjectInstance executedProject)

src/Workspaces/Core/Desktop/WorkspaceDesktopResources.Designer.cs

@@ -60,15 +60,6 @@ internal class WorkspaceDesktopResources {
             }
         }
         
-        /// <summary>
-        ///   Looks up a localized string similar to Cannot open project &apos;{0}&apos; because msbuild failed with message: {1}.
-        /// </summary>
-        internal static string Cannot_open_project_0_because_msbuild_failed_with_message_1 {
-            get {
-                return ResourceManager.GetString("Cannot_open_project_0_because_msbuild_failed_with_message_1", resourceCulture);
-            }
-        }
-        
         /// <summary>
         ///   Looks up a localized string similar to Invalid assembly name.
         /// </summary>
@@ -87,6 +78,24 @@ internal class WorkspaceDesktopResources {
             }
         }
         
+        /// <summary>
+        ///   Looks up a localized string similar to Msbuild failed when processing the file &apos;{0}&apos;.
+        /// </summary>
+        internal static string Msbuild_failed_when_processing_the_file_0 {
+            get {
+                return ResourceManager.GetString("Msbuild_failed_when_processing_the_file_0", resourceCulture);
+            }
+        }
+        
+        /// <summary>
+        ///   Looks up a localized string similar to Msbuild failed when processing the file &apos;{0}&apos; with message: {1}.
+        /// </summary>
+        internal static string Msbuild_failed_when_processing_the_file_0_with_message_1 {
+            get {
+                return ResourceManager.GetString("Msbuild_failed_when_processing_the_file_0_with_message_1", resourceCulture);
+            }
+        }
+        
         /// <summary>
         ///   Looks up a localized string similar to .
         /// </summary>

src/Workspaces/Core/Desktop/WorkspaceDesktopResources.resx

@@ -117,15 +117,18 @@
   <resheader name="writer">
     <value>System.Resources.ResXResourceWriter, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>
   </resheader>
-  <data name="Cannot_open_project_0_because_msbuild_failed_with_message_1" xml:space="preserve">
-    <value>Cannot open project '{0}' because msbuild failed with message: {1}</value>
-  </data>
   <data name="Invalid_assembly_name" xml:space="preserve">
     <value>Invalid assembly name</value>
   </data>
   <data name="Invalid_characters_in_assembly_name" xml:space="preserve">
     <value>Invalid characters in assembly name</value>
   </data>
+  <data name="Msbuild_failed_when_processing_the_file_0" xml:space="preserve">
+    <value>Msbuild failed when processing the file '{0}'</value>
+  </data>
+  <data name="Msbuild_failed_when_processing_the_file_0_with_message_1" xml:space="preserve">
+    <value>Msbuild failed when processing the file '{0}' with message: {1}</value>
+  </data>
   <data name="String1" xml:space="preserve">
     <value />
   </data>

src/Workspaces/Core/Desktop/Workspaces.Desktop.csproj

@@ -111,7 +111,6 @@
     <Compile Include="Workspace\MSBuild\CSharp\CSharpProjectFileLoader.CSharpProjectFile.cs" />
     <Compile Include="Workspace\MSBuild\CSharp\CSharpProjectFileLoaderFactory.cs" />
     <Compile Include="Workspace\MSBuild\MSBuildWorkspace.cs" />
-    <Compile Include="Workspace\MSBuild\ProjectFile\BuildTargets.cs" />
     <Compile Include="Workspace\MSBuild\ProjectFile\DocumentFileInfo.cs" />
     <Compile Include="Workspace\MSBuild\ProjectFile\IProjectFile.cs" />
     <Compile Include="Workspace\MSBuild\ProjectFile\IProjectFileLoader.cs" />

src/Workspaces/CoreTest/ServicesTest.csproj

@@ -289,6 +289,11 @@
       <SubType>Designer</SubType>
     </EmbeddedResource>
   </ItemGroup>
+  <ItemGroup>
+    <EmbeddedResource Include="TestFiles\CSharpProject_CSharpProject_MsbuildError.csproj">
+      <SubType>Designer</SubType>
+    </EmbeddedResource>
+  </ItemGroup>
   <Import Project="..\..\..\build\Targets\Imports.targets" />
   <Import Project="..\..\..\build\Targets\Roslyn.Toolsets.Xunit.targets" />
 </Project>
\ No newline at end of file

src/Workspaces/CoreTest/TestFiles/CSharpProject_CSharpProject_MsbuildError.csproj

+<?xml version="1.0" encoding="utf-8"?>
+<!-- Copyright (c)  Microsoft.  All Rights Reserved.  Licensed under the Apache License, Version 2.0.  See License.txt in the project root for license information. -->
+<Project ToolsVersion="4.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <PropertyGroup>
+    <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
+    <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
+    <ProductVersion>8.0.30703</ProductVersion>
+    <SchemaVersion>2.0</SchemaVersion>
+    <ProjectGuid>{686DD036-86AA-443E-8A10-DDB43266A8C4}</ProjectGuid>
+    <OutputType>Library</OutputType>
+    <AppDesignerFolder>Properties</AppDesignerFolder>
+    <RootNamespace>CSharpProject</RootNamespace>
+    <AssemblyName>CSharpProject</AssemblyName>
+    <TargetFrameworkVersion>v4.0</TargetFrameworkVersion>
+    <FileAlignment>512</FileAlignment>
+    <AssemblyOriginatorKeyFile>snKey.snk</AssemblyOriginatorKeyFile>
+  </PropertyGroup>
+  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
+    <DebugSymbols>true</DebugSymbols>
+    <DebugType>full</DebugType>
+    <Optimize>false</Optimize>
+    <OutputPath>bin\Debug\</OutputPath>
+    <DefineConstants>DEBUG;TRACE</DefineConstants>
+    <ErrorReport>prompt</ErrorReport>
+    <WarningLevel>4</WarningLevel>
+  </PropertyGroup>
+  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
+    <DebugType>pdbonly</DebugType>
+    <Optimize>true</Optimize>
+    <OutputPath>bin\Release\</OutputPath>
+    <DefineConstants>TRACE</DefineConstants>
+    <ErrorReport>prompt</ErrorReport>
+    <WarningLevel>4</WarningLevel>
+  </PropertyGroup>
+  <ItemGroup>
+    <Reference Include="Microsoft.CSharp" />
+    <Reference Include="System" />
+    <Reference Include="System.Core" />
+  </ItemGroup>
+  <ItemGroup>
+    <Compile Include="CSharpClass.cs" />
+    <Compile Include="Properties\AssemblyInfo.cs" />
+  </ItemGroup>
+  <PropertyGroup>
+    <CompileDependsOn>TestError;$(CompileDependsOn)</CompileDependsOn>
+  </PropertyGroup>
+  <Target Name="TestError" BeforeTargets="CoreCompile">
+    <Error Text="This is a test of the msbuild error system. This is only a test." />
+  </Target>
+  <Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" />
+</Project>

src/Workspaces/CoreTest/WorkspaceTests/MSBuildWorkspaceTests.cs

@@ -1265,20 +1265,14 @@ public void TestOpenProject_WithUnrecognizedProjectReferenceFileExtension_BadMsb
             Workspace.TestHookStandaloneProjectsDoNotHoldReferences = true;
 
             var ws = MSBuildWorkspace.Create();
-
-            var diags = new List<WorkspaceDiagnostic>();
-            ws.WorkspaceFailed += (s, args) =>
-            {
-                diags.Add(args.Diagnostic);
-            };
-
             ws.SkipUnrecognizedProjects = true;
+
             var project = ws.OpenProjectAsync(GetSolutionFileName(@"VisualBasicProject\VisualBasicProject.vbproj")).Result;
 
             Assert.Equal(1, project.Solution.ProjectIds.Count);
             Assert.Equal(0, project.ProjectReferences.Count());
             Assert.Equal(1, project.AllProjectReferences.Count());
-            Assert.Equal(1, diags.Count);
+            Assert.Equal(1, ws.Diagnostics.Count);
         }
 
         [Fact(Skip = "https://roslyn.codeplex.com/workitem/451"), Trait(Traits.Feature, Traits.Features.Workspace)]
@@ -2923,17 +2917,10 @@ public async Task TestOpenProject_BadTaskImport()
                 .WithFile(@"CSharpProject\CSharpProject.csproj", GetResourceText(@"CSharpProject_CSharpProject_BadTasks.csproj")));
 
             var ws = MSBuildWorkspace.Create();
-            string message = null;
-
-            ws.WorkspaceFailed += (sender, args) =>
-            {
-                message = args.Diagnostic.Message;
-            };
-
             var proj = await ws.OpenProjectAsync(GetSolutionFileName(@"CSharpProject\CSharpProject.csproj"));
 
-            Assert.NotNull(message);
-            Assert.True(message.StartsWith("Cannot open"));
+            Assert.Equal(1, ws.Diagnostics.Count);
+            Assert.True(ws.Diagnostics[0].Message.StartsWith("Msbuild failed"));
 
             Assert.Equal(0, proj.DocumentIds.Count);
         }
@@ -2945,22 +2932,28 @@ public async Task TestOpenSolution_BadTaskImport()
                 .WithFile(@"CSharpProject\CSharpProject.csproj", GetResourceText(@"CSharpProject_CSharpProject_BadTasks.csproj")));
 
             var ws = MSBuildWorkspace.Create();
-            string message = null;
-
-            ws.WorkspaceFailed += (sender, args) =>
-            {
-                message = args.Diagnostic.Message;
-            };
-
             var solution = await ws.OpenSolutionAsync(GetSolutionFileName(@"TestSolution.sln"));
 
-            Assert.NotNull(message);
-            Assert.True(message.StartsWith("Cannot open"));
+            Assert.Equal(1, ws.Diagnostics.Count);
+            Assert.True(ws.Diagnostics[0].Message.StartsWith("Msbuild failed"));
 
             Assert.Equal(1, solution.ProjectIds.Count);
             Assert.Equal(0, solution.Projects.First().DocumentIds.Count);
         }
 
+        [Fact, Trait(Traits.Feature, Traits.Features.Workspace)]
+        public async Task TestOpenProject_MsbuildError()
+        {
+            CreateFiles(GetSimpleCSharpSolutionFiles()
+                .WithFile(@"CSharpProject\CSharpProject.csproj", GetResourceText(@"CSharpProject_CSharpProject_MsbuildError.csproj")));
+
+            var ws = MSBuildWorkspace.Create();
+            var proj = await ws.OpenProjectAsync(GetSolutionFileName(@"CSharpProject\CSharpProject.csproj"));
+
+            Assert.Equal(1, ws.Diagnostics.Count);
+            Assert.True(ws.Diagnostics[0].Message.StartsWith("Msbuild failed"));
+        }
+
         [Fact, Trait(Traits.Feature, Traits.Features.Workspace)]
         public void TestOpenProject_CommandLineArgsHaveNoErrors()
         {