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Cannot get SyntaxTree from Compilation object

I'm a beginner of roslyn, so I tried to start learning it by making a very simple console application, which is introduced in the famous tutorial site. (https://riptutorial.com/roslyn/example/16545/introspective-analysis-of-an-analyzer-in-csharp), and it didn't work well.
The Cosole Application I made is of .NET Framework (target Framework version is 4.7.2), and not of .NET Core nor .NET standard.
I added the NuGet package Microsoft.CodeAnalysis, and Microsoft.CodeAnalysis.Workspaces.MSBuild, then wrote a simple code as I show below.
using Microsoft.CodeAnalysis.CSharp.Syntax;
using Microsoft.CodeAnalysis.MSBuild;
using System;
using System.Linq;
namespace SimpleRoslynConsole
{
class Program
{
static void Main(string[] args)
{
// Declaring a variable with the current project file path.
// *** You have to change this path to fit your development environment.
const string projectPath =
#"C:\Users\[MyName]\Source\Repos\RoslynTrialConsole01\RoslynTrialConsole01.csproj";
var workspace = MSBuildWorkspace.Create();
var project = workspace.OpenProjectAsync(projectPath).Result;
// [**1]Getting the compilation.
var compilation = project.GetCompilationAsync().Result;
// [**2]As this is a simple single file program, the first syntax tree will be the current file.
var syntaxTree = compilation.SyntaxTrees.FirstOrDefault();
if (syntaxTree != null)
{
var rootSyntaxNode = syntaxTree.GetRootAsync().Result;
var firstLocalVariablesDeclaration = rootSyntaxNode.DescendantNodesAndSelf()
.OfType<LocalDeclarationStatementSyntax>().First();
var firstVariable = firstLocalVariablesDeclaration.Declaration.Variables.First();
var variableInitializer = firstVariable.Initializer.Value.GetFirstToken().ValueText;
Console.WriteLine(variableInitializer);
}
else
{
Console.WriteLine("Could not get SyntaxTrees from this projects.");
}
Console.WriteLine("Hit any key.");
Console.ReadKey();
}
}
}
My problem is that, SyntaxTrees property of Compilation object returns null in [**2]mark. Naturally, following FirstOrDefault method returns null.
I've tried several other code. I found I could get SyntaxTree from CSharp code text, by using CSharpSyntaxTree.ParseText method. But I couldn't get any from source code, by the sequence of
var workspace = MSBuildWorkspace.Create();
var project = workspace.OpenProjectAsync(projectPath).Result;
var compilation = project.GetCompilationAsync().Result;
What I'd like to know is if I miss something to get Syntax information from source code by using above process.
I'll appreciate someone give me a good advice.

I think the issue is that .net framework projects have their source files paths within their .csproj. And opening project works right away.
For .net core project you have no such information and, maybe, this is why Workspace instance doesn't know what to load and so loads nothing.
At least specifying .cs files as added documents does the trick. Try to apply this:
static class ProjectExtensions
{
public static Project AddDocuments(this Project project, IEnumerable<string> files)
{
foreach (string file in files)
{
project = project.AddDocument(file, File.ReadAllText(file)).Project;
}
return project;
}
private static IEnumerable<string> GetAllSourceFiles(string directoryPath)
{
var res = Directory.GetFiles(directoryPath, "*.cs", SearchOption.AllDirectories);
return res;
}
public static Project WithAllSourceFiles(this Project project)
{
string projectDirectory = Directory.GetParent(project.FilePath).FullName;
var files = GetAllSourceFiles(projectDirectory);
var newProject = project.AddDocuments(files);
return newProject;
}
}
Method WithAllsourceFiles will return you the project, compilation of which will in its turn have all syntax trees you would expect of it, as you would have in Visual Studio

MsBuildWorkspace won't work correctly unless you have all the same redirects in your app's app.config file that msbuild.exe.config has in it. Without the redirects, it's probably failing to load the msbuild libraries. You need to find the msbuild.exe.config file that is on your system and copy the <assemblyBinding> elements related to Microsoft.Build assemblies into your app.config. Make sure you place them under the correct elements configuration/runtime.

I searched various sample programs on the net and found the most reliable and safest method. The solution is to create a static method which returns SyntaxTrees in designated File as follow.
private static Compilation CreateTestCompilation()
{
var found = false;
var di = new DirectoryInfo(Environment.CurrentDirectory);
var fi = di.GetFiles().Where((crt) => { return crt.Name.Equals("program.cs", StringComparison.CurrentCultureIgnoreCase); }).FirstOrDefault();
while ((fi == null) || (di.Parent == null))
{
di = new DirectoryInfo(di.Parent.FullName);
fi = di.GetFiles().Where((crt) => { return crt.Name.Equals("program.cs", StringComparison.CurrentCultureIgnoreCase); }).FirstOrDefault();
if (fi != null)
{
found = true;
break;
}
}
if (!found)
{
return null;
}
var targetPath = di.FullName + #"\Program.cs";
var targetText = File.ReadAllText(targetPath);
var targetTree =
CSharpSyntaxTree.ParseText(targetText)
.WithFilePath(targetPath);
var target2Path = di.FullName + #"\TypeInferenceRewriter.cs";
var target2Text = File.ReadAllText(target2Path);
var target2Tree =
CSharpSyntaxTree.ParseText(target2Text)
.WithFilePath(target2Path);
SyntaxTree[] sourceTrees = { programTree, target2Tree };
MetadataReference mscorlib =
MetadataReference.CreateFromFile(typeof(object).Assembly.Location);
MetadataReference codeAnalysis =
MetadataReference.CreateFromFile(typeof(SyntaxTree).Assembly.Location);
MetadataReference csharpCodeAnalysis =
MetadataReference.CreateFromFile(typeof(CSharpSyntaxTree).Assembly.Location);
MetadataReference[] references = { mscorlib, codeAnalysis, csharpCodeAnalysis };
return CSharpCompilation.Create("TransformationCS",
sourceTrees,
references,
new CSharpCompilationOptions(
OutputKind.ConsoleApplication));
}
And the caller program will be like this.
static void Main(string[] args)
{
var test = CreateTestCompilation();
if (test == null)
{
return;
}
foreach (SyntaxTree sourceTree in test.SyntaxTrees)
{
Console.WriteLine(souceTree.ToFullString());
}
}
Of course, many improvements are needed to put it to practical use.

How to install Nuget Packages using ENVDTE.DTE

I created one console application to create visual studio project pragmatically, here i am not able install Nuget packages, always
var componentModel = (IComponentModel)Package.GetGlobalService(typeof(SComponentModel)); statement returns null values. for your reference i added my code below. Help me to resolve this issue.
static void Main(string[] args)
{
//InstallNuGetPackages.InstallNuGet("");
string ProjectName = "WebAPIProj";
string SolutionName = "EmptyTemplate";
System.Type type = System.Type.GetTypeFromProgID("VisualStudio.DTE.11.0");
Object obj = System.Activator.CreateInstance(type, true);
EnvDTE.DTE dte = (EnvDTE.DTE)obj;
dte.MainWindow.Visible = true; // optional if you want to See VS doing its thing
// create a new solution
dte.Solution.Create("C:\\"+ SolutionName + "\\", SolutionName);
var solution = dte.Solution;
// create a C# WinForms app
solution.AddFromTemplate(#"C:\Program Files (x86)\Microsoft Visual Studio 11.0\Common7\IDE\ProjectTemplatesCache\CSharp\Web\1033\EmptyWebApplicationProject40\EmptyWebApplicationProject40.vstemplate",
#"C:\NewSolution\"+ ProjectName, ProjectName);
InstallNuGetPackages.InstallNuGet(dte);
foreach (var p in dte.Solution.Projects)
{
InstallNuGetPackages.InstallNuGet((Project)p, "Microsoft.AspNet.WebApi version1.1");
}
// save and quit
dte.ExecuteCommand("File.SaveAll");
dte.Quit();
}
Code to install Nuget Packages
public bool InstallNuGetPackage(Project project, string package)
{
bool installedPkg = true;
try
{
var componentModel = (IComponentModel)Package.GetGlobalService(typeof(SComponentModel)); //Always this statement returns null
IVsPackageInstallerServices installerServices = componentModel.GetService();
if (!installerServices.IsPackageInstalled(project, package))
{
var installer = componentModel.GetService();
installer.InstallPackage(null, project, package, (System.Version)null, false);
}
}
catch (Exception ex)
{
installedPkg = false;
}
return installedPkg;
}

(Turned this into an answer for better readability and more room)
created one console application - you only have access to the ServiceProvider from Visual Studio if you run your code inside of it, i.e. from an extension and/or package.
Running this from a console application cannot work. Visual Studio internally does a lot more setup for all the services and general environment than creating an instance of DTE.
To persue your route, although I'm not sure how feasible that is, invoke nuget.exe or NuGet.Core code to achieve similar.

Visual Studio 2015 build drop location

Our company recently updated TFS to 2015 update 1. After that context menu item named Drop folder disappeared from completed builds. I found nothing about it and how to bring it back. When I click Open on completed build, VS opens web version of TFS where I forced to click through the menus and copy drop folder path manually. So I decided to write a simple extension that will add this item to the menu.
Some googling brought me to this page. But it seems that the example code is quite old and not working in VS2015:
IVsTeamFoundationBuild vsTfBuild = (IVsTeamFoundationBuild)GetService(typeof(IVsTeamFoundationBuild));
IBuildDetail[] builds = vsTfBuild.BuildExplorer.CompletedView.SelectedBuilds;
Property SelectedBuilds is always empty. I suppose that it relates to old window from VS2010. It returns items that are instance of IBuildDetail interface.
So I found this piece of code here:
var teamExplorer = (ITeamExplorer)ServiceProvider.GetService(typeof(ITeamExplorer));
var page = teamExplorer.CurrentPage;
var buildsPageExt = (IBuildsPageExt)page.GetExtensibilityService(typeof(IBuildsPageExt));
var build = buildsPageExt.SelectedBuilds[0];
Here build is the instance of IBuildModel interface. It lacks DropLocation property.
Is there any way to found drop location of selected build? Or maybe latest build?

You can use IBuildDedetail.DropLocation in .NET client libraries for Visual Studio Team Services (and TFS). Basic code for your reference:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using Microsoft.TeamFoundation.Build.Client;
using Microsoft.TeamFoundation.Client;
namespace BuildAPI
{
class Program
{
static void Main(string[] args)
{
string project = "http://xxx.xxx.xxx.xxx";
TfsTeamProjectCollection tpc = new TfsTeamProjectCollection(new Uri(project));
IBuildServer ibs = tpc.GetService<IBuildServer>();
var builds = ibs.QueryBuilds("TeamProjectName");
foreach (IBuildDetail ibd in builds)
{
Console.WriteLine(ibd.DropLocation);
Console.ReadLine();
}
}
}
}

So, after digging through TFS API, I ended up with this workaround.
private void MenuItemCallback(object sender, EventArgs e)
{
var context = (ITeamFoundationContextManager)ServiceProvider.GetService(typeof(ITeamFoundationContextManager));
IBuildServer buildServer = context.CurrentContext.TeamProjectCollection.GetService<IBuildServer>();
var teamExplorer = (ITeamExplorer)ServiceProvider.GetService(typeof(ITeamExplorer));
var buildsPageExt = (IBuildsPageExt)teamExplorer.CurrentPage.GetExtensibilityService(typeof(IBuildsPageExt));
var menuCommand = (MenuCommand)sender;
if (menuCommand.CommandID.Guid == CommandSetCompleted)
{
foreach (var buildDetail in buildsPageExt.SelectedBuilds)
Process.Start("explorer.exe", GetBuild(buildServer, buildDetail).DropLocation);
}
if (menuCommand.CommandID.Guid == CommandSetFavorite)
{
var definitions = buildsPageExt.SelectedFavoriteDefinitions.Concat(buildsPageExt.SelectedXamlDefinitions).ToArray();
foreach (var build in GetLatestSuccessfulBuild(buildServer, definitions))
Process.Start("explorer.exe", build.DropLocation);
}
}
private IBuildDetail GetBuild(IBuildServer buildServer, IBuildModel buildModel)
{
Uri buildUri = new Uri(buildModel.GetType().GetProperty("UriToOpen").GetValue(buildModel).ToString());
return buildServer.GetBuild(buildUri);
}
private IBuildDetail[] GetLatestSuccessfulBuild(IBuildServer buildServer, IDefinitionModel[] buildDefinitions)
{
var spec = buildServer.CreateBuildDetailSpec(buildDefinitions.Select(bd => bd.Uri));
spec.MaxBuildsPerDefinition = 1;
spec.QueryOrder = BuildQueryOrder.FinishTimeDescending;
spec.Status = BuildStatus.Succeeded;
var builds = buildServer.QueryBuilds(spec);
return builds.Builds;
}

How to debug code compiled with Roslyn in a Visual Studio extension inside current Visual Studio host?

I have a Visual Studio extensions that use Roslyn to get a project in current opened solution, compile it and run methods from it. The project can be modified by the programmer.
I have successfully compiled a project in a Visual Studio extension from the current VisualStudioWorkspace.
private static Assembly CompileAndLoad(Compilation compilation)
{
using (MemoryStream dllStream = new MemoryStream())
using (MemoryStream pdbStream = new MemoryStream())
{
EmitResult result = compilation.Emit(dllStream, pdbStream);
if (!result.Success)
{
IEnumerable<Diagnostic> failures = result.Diagnostics.Where(diagnostic =>
diagnostic.IsWarningAsError ||
diagnostic.Severity == DiagnosticSeverity.Error);
string failuresException = "Failed to compile code generation project : \r\n";
foreach (Diagnostic diagnostic in failures)
{
failuresException += $"{diagnostic.Id} : {diagnostic.GetMessage()}\r\n";
}
throw new Exception(failuresException);
}
else
{
dllStream.Seek(0, SeekOrigin.Begin);
return AppDomain.CurrentDomain.Load(dllStream.ToArray(), pdbStream.ToArray());
}
}
}
Then I can load the assembly in current domain, get it's types and invoke methods.
The problem is that I need to allow the programmer to put breakpoints if the current configuration of the loaded solution is debug.
I need to run some code in current Visual Studio Host from an extension and allow it to be debugged in the current Visual Studio instance.

Seems like this is actually impossible.
The current visual studio instance cannot debug itself.
I've tried creating a Console Application with roslyn, attaching it to the debugger and then run the generation code from it. But the VisualStudioWorkspace is only available inside VisualStudio (Not serializable and not avalaible througt DTE com interface). So the only solution left was using MBBuildWorkspace. Since it does not have that same behavior as Visual studio workspace, I've abandoned the project.
Here's my code for further references :
Process vsProcess = Process.GetCurrentProcess();
string solutionPath = CurrentWorkspace.CurrentSolution.FilePath;
SyntaxTree syntaxTree = CSharpSyntaxTree.ParseText($#"
using System;
using System.Threading.Tasks;
namespace CodeGenApplication
{{
public class Program
{{
public static void Main(string[] args)
{{
Console.ReadLine();
int vsProcessId = Int32.Parse(args[0]);
CodeGenApp.Test(""{solutionPath.Replace(#"\", #"\\")}"", ""{projectName}"", ""{_codeGenProjectName}"");
Console.ReadLine();
}}
}}
}}");
string assemblyName = Path.GetRandomFileName();
Project codeGenProject = CurrentWorkspace.CurrentSolution.Projects.Where(x => x.Name == _codeGenProjectName).FirstOrDefault();
List<MetadataReference> references = codeGenProject.MetadataReferences.ToList();
CSharpCompilation compilation = CSharpCompilation.Create(
assemblyName,
syntaxTrees: new[] { syntaxTree },
references: references,
options: new CSharpCompilationOptions(OutputKind.ConsoleApplication));
// Emit assembly to streams.
EmitResult result = compilation.Emit("CodeGenApplication.exe", "CodeGenApplication.pdb");
if (!result.Success)
{
IEnumerable<Diagnostic> failures = result.Diagnostics.Where(diagnostic =>
diagnostic.IsWarningAsError ||
diagnostic.Severity == DiagnosticSeverity.Error);
}
else
{
Process codeGenProcess = new Process();
codeGenProcess.StartInfo.FileName = "CodeGenApplication.exe";
codeGenProcess.StartInfo.Arguments = vsProcess.Id.ToString();
codeGenProcess.StartInfo.UseShellExecute = false;
codeGenProcess.StartInfo.CreateNoWindow = true;
codeGenProcess.StartInfo.LoadUserProfile = true;
codeGenProcess.StartInfo.RedirectStandardError = true;
codeGenProcess.StartInfo.RedirectStandardInput = true;
codeGenProcess.StartInfo.RedirectStandardOutput = false;
codeGenProcess.Start();
foreach (EnvDTE.Process dteProcess in _dte.Debugger.LocalProcesses)
{
if (dteProcess.ProcessID == codeGenProcess.Id)
{
dteProcess.Attach();
}
}
codeGenProcess.StandardInput.WriteLine("Start");
}

You have to attach the debugger to the currently running visual studio host. To do that you need to:
Get hold of the DTE object,
find the (current) process in DTE.Debugger.LocalProcesses
Attach the debugger - example
run method from the compiled assembly
You'd probably want a separate command/button for this, don't just switch on the current build configuration. That's how everybody else does it (e.g. test runners and even Visual Studio). Also, load the compiled Assembly in a new AppDomain, otherwise it'll stick around for ever.
There's also the more "creative" solution of injecting a System.Diagnostics.Debugger.Launch() call to the method you're about to run (modify the correct Compilation.SyntaxTrees before calling Emit) - but seriously, don't do this.

Project Names in Visual Studio Solution sometimes are empty

In visual studio extension I would like to get all projects and their names:
var service = (DTE) Package.GetGlobalService(typeof (SDTE));
var projects = service.Solution.Projects;
foreach (Project project in projects)
//....
This approach work nice and neat for exception of one little problem:
project variable returns really exact number of project. But project's full name might be EMPTY if it located in the solution's folder. (I mean the structure of solution when projects are united in the solution's folder)
How to get these project properly?

Here is a solution.
This guy is the Lord of Rings as minimum:
http://www.wwwlicious.com/2011/03/29/envdte-getting-all-projects-html/
Relevant information from the blog, in case it goes away (like so many other answers on Stack Overflow):
DTE2.Solution.Projects will only give you the top level list of items under the Solution so any projects nested within Solution Folders are missed. In order to get at these pesky little worms, you need to burrow into the ProjectItem.SubProject property accessed from the ProjectItems collection on the the Project. Just to cap the whole lot off, if you have nested solution folders, then you need some recursion.
using System.Collections.Generic;
using EnvDTE;
using EnvDTE80;
public static class SolutionProjects
{
public static DTE2 GetActiveIDE()
{
// Get an instance of currently running Visual Studio IDE.
DTE2 dte2 = Package.GetGlobalService(typeof(DTE)) as DTE2;
return dte2;
}
public static IList<Project> Projects()
{
Projects projects = GetActiveIDE().Solution.Projects;
List<Project> list = new List<Project>();
var item = projects.GetEnumerator();
while (item.MoveNext())
{
var project = item.Current as Project;
if (project == null)
{
continue;
}
if (project.Kind == ProjectKinds.vsProjectKindSolutionFolder)
{
list.AddRange(GetSolutionFolderProjects(project));
}
else
{
list.Add(project);
}
}
return list;
}
private static IEnumerable<Project> GetSolutionFolderProjects(Project solutionFolder)
{
List<Project> list = new List<Project>();
for (var i = 1; i <= solutionFolder.ProjectItems.Count; i++)
{
var subProject = solutionFolder.ProjectItems.Item(i).SubProject;
if (subProject == null)
{
continue;
}
// If this is another solution folder, do a recursive call, otherwise add
if (subProject.Kind == ProjectKinds.vsProjectKindSolutionFolder)
{
list.AddRange(GetSolutionFolderProjects(subProject));
}
else
{
list.Add(subProject);
}
}
return list;
}
}