Merge pull request #8 from carldebilly/dev/cdb/generator-reversed-dependency

Added ability to define generator dependencies in both ways.
The previous `[SourceGeneratorDependency]` attribute has been replaced by `[GenerateBefore]` and a new `[GenerateAfter]` attribute for the opposite.

readme.md

@@ -135,10 +135,11 @@ This will open another visual studio instance, and allow for stepping through th
 * Generators should have the least possible external dependencies.
   Generators are loaded in a separate `AppDomain` but multiple assemblies versions can be
   troublesome when loaded side by side.
+
 * You can add a dependency on your generator by adding the `Uno.SourceGeneration.SourceGeneratorDependency`
   attribute on your class:
 	```csharp
-	[SourceGeneratorDependency("Uno.ImmutableGenerator")]
+	[GenerateAfter("Uno.ImmutableGenerator")] // Generate ImmutableGenerator before EqualityGenerator
 	public class EqualityGenerator : SourceGenerator
 	```
   For instance here, it will ensure that the `ImmutableGenerator` is executed before your `EqualityGenerator`.
@@ -146,10 +147,14 @@ This will open another visual studio instance, and allow for stepping through th
   from a generator are excluded from the roslyn `Compilation` object of other generators, meaning that if
   two generators use the same conditions to generate the same code, there will be a compilation
   error in the resulting code.
-* If you need a generator to use the result of another one for its own compilation, you can use
-  the `[SourceGeneratorDependency]` attribute. You simply need to specify the FullName
-  (namespace + type name) of another generator.  If this generator is found, it will ensure it
-  is executed before and the result is added to the compilation before calling yours.
+  
+* You can also define a generator which must be executed **after** yours. To do this, you need to declare a
+  _dependent generator_:
+  ```csharp
+  [GenerateBefore("Uno.EqualityGenerator")] // Generate ImmutableGenerator before EqualityGenerator
+  public class ImmutableGenerator : SourceGenerator
+  ```
+
 * Sometimes you may need to kill all instances of MsBuild. On Windows, the fatest way to to that
   is to open a shell in admin mode and type this line:
   ```

src/Uno.SampleGenerators/AnotherCustomSourceGenerator.cs

@@ -18,8 +18,7 @@ using Uno.SourceGeneration;
 
 namespace Uno.SampleGenerators
 {
-	[SourceGeneratorDependency("Uno.SampleGenerators.MyCustomSourceGenerator")]
-	[SourceGeneratorDependency("Uno.SampleGenerators.UselessGenerator")]
+	[GenerateAfter("Uno.SampleGenerators.MyCustomSourceGenerator")]
 	public class AnotherCustomSourceGenerator : SourceGenerator
 	{
 		public override void Execute(SourceGeneratorContext context)

src/Uno.SampleGenerators/UselessGenerator.cs

@@ -18,6 +18,7 @@ using Uno.SourceGeneration;
 
 namespace Uno.SampleGenerators
 {
+	[GenerateBefore("Uno.SampleGenerators.AnotherCustomSourceGenerator")]
 	public class UselessGenerator : SourceGenerator
 	{
 		public override void Execute(SourceGeneratorContext context)

src/Uno.SampleProject.UWP/GeneratedFiles/g/MyCustomSourceGenerator/Test.g.cs

@@ -1,7 +1,8 @@
 
 namespace Test {
-	class MyGeneratedType 
+	public static class MyGeneratedType 
 	{
-		// Project: C:\s\Uno.SourceGenerator\Uno.SourceGenerator\Uno.SampleProject.UWP\Uno.SampleProject.UWP.csproj
+		// Project: C:\src\uno.sourcegeneration\src\Uno.SampleProject.UWP\Uno.SampleProject.UWP.csproj
+		public const string Project = @"C:\src\uno.sourcegeneration\src\Uno.SampleProject.UWP\Uno.SampleProject.UWP.csproj";
 	}
 }

src/Uno.SampleProject/GeneratedFiles/g/MyCustomSourceGenerator/Test.g.cs

@@ -1,7 +1,8 @@
 
 namespace Test {
-	class MyGeneratedType 
+	public static class MyGeneratedType 
 	{
-		// Project: /Users/admin/Documents/s/Uno.SourceGenerator/Uno.SourceGenerator/Uno.SampleProject/Uno.SampleProject.csproj
+		// Project: C:\src\uno.sourcegeneration\src\Uno.SampleProject\Uno.SampleProject.csproj
+		public const string Project = @"C:\src\uno.sourcegeneration\src\Uno.SampleProject\Uno.SampleProject.csproj";
 	}
 }

src/Uno.SourceGeneration/GenerateAfterAttribute.cs

@@ -0,0 +1,50 @@
+// ******************************************************************
+// Copyright <20> 2015-2018 nventive inc. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+// ******************************************************************
+using System;
+
+namespace Uno.SourceGeneration
+{
+	/// <summary>
+	/// Defines a dependency between source generators
+	/// </summary>
+	/// <remarks>
+	/// Can be defined more than once for a generator.
+	/// No effect when generator is not found.
+	/// </remarks>
+	[AttributeUsage(AttributeTargets.Class, AllowMultiple = true, Inherited = false)]
+	public class GenerateAfterAttribute : Attribute
+	{
+		/// <summary>
+		/// Fully Qualified Name (FQN: namespace + class name) of the generator to execute before.
+		/// </summary>
+		/// <remarks>
+		/// No effect if the generator is not found.
+		/// </remarks>
+		public string GeneratorToExecuteBefore { get; }
+
+		/// <summary>
+		/// Defines a dependency between source generators
+		/// </summary>
+		/// <param name="generatorToExecuteBefore">
+		/// Fully Qualified Name (FQN: namespace + class name) of the generator to execute before
+		/// </param>
+		public GenerateAfterAttribute(string generatorToExecuteBefore)
+		{
+			GeneratorToExecuteBefore = generatorToExecuteBefore;
+		}
+	}
+}

src/Uno.SourceGeneration/GenerateBeforeAttribute.cs

@@ -0,0 +1,50 @@
+// ******************************************************************
+// Copyright <20> 2015-2018 nventive inc. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+// ******************************************************************
+using System;
+
+namespace Uno.SourceGeneration
+{
+	/// <summary>
+	/// Defines a dependent source generators, which should be executed after
+	/// </summary>
+	/// <remarks>
+	/// Can be defined more than once for a generator.
+	/// No effect when generator is not found.
+	/// </remarks>
+	[AttributeUsage(AttributeTargets.Class, AllowMultiple = true, Inherited = false)]
+	public class GenerateBeforeAttribute : Attribute
+	{
+		/// <summary>
+		/// Fully Qualified Name (FQN: namespace + class name) of the generator to execute after.
+		/// </summary>
+		/// <remarks>
+		/// No effect if the generator is not found.
+		/// </remarks>
+		public string GeneratorToExecuteAfter { get; }
+
+		/// <summary>
+		/// Defines a dependent source generators, which should be executed after
+		/// </summary>
+		/// <param name="generatorToExecuteAfter">
+		/// Fully Qualified Name (FQN: namespace + class name) of the generator to execute after.
+		/// </param>
+		public GenerateBeforeAttribute(string generatorToExecuteAfter)
+		{
+			GeneratorToExecuteAfter = generatorToExecuteAfter;
+		}
+	}
+}

src/Uno.SourceGeneration/SourceGenerator.cs

@@ -14,12 +14,6 @@
 // limitations under the License.
 //
 // ******************************************************************
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Text;
-using System.Threading.Tasks;
-
 namespace Uno.SourceGeneration
 {
 	public abstract class SourceGenerator

src/Uno.SourceGeneration/SourceGeneratorDependencyAttribute.cs

@@ -1,28 +0,0 @@
-using System;
-
-namespace Uno.SourceGeneration
-{
-	/// <summary>
-	/// Define a dependency between source generators
-	/// </summary>
-	/// <remarks>
-	/// Can be define more than once for a generator.
-	/// No effect when generator is not found.
-	/// </remarks>
-	[AttributeUsage(AttributeTargets.Class, AllowMultiple = true, Inherited = false)]
-	public class SourceGeneratorDependencyAttribute : Attribute
-	{
-		/// <summary>
-		/// Fully Qualified Name (FQN: namespace + class name) of the generator to execute before.
-		/// </summary>
-		/// <remarks>
-		/// No effect if the generator is not found.
-		/// </remarks>
-		public string DependsOn { get; }
-
-		public SourceGeneratorDependencyAttribute(string dependsOn)
-		{
-			DependsOn = dependsOn;
-		}
-	}
-}

src/Uno.SourceGeneration/Uno.SourceGeneration.csproj

@@ -78,7 +78,8 @@
     <Compile Include="..\..\Build\AssemblyVersion.cs">
       <Link>AssemblyVersion.cs</Link>
     </Compile>
-    <Compile Include="SourceGeneratorDependencyAttribute.cs" />
+    <Compile Include="GenerateBeforeAttribute.cs" />
+    <Compile Include="GenerateAfterAttribute.cs" />
     <Compile Include="SourceGeneratorExtensions.cs" />
     <Compile Include="Properties\AssemblyInfo.cs" />
     <Compile Include="SourceGenerator.cs" />

src/Uno.SourceGenerationHost.Shared/SourceGeneratorHost.cs

@@ -77,33 +77,49 @@ namespace Uno.SourceGeneration.Host
 			var generatorNames = generatorsByName.Keys;
 
 			// Dependencies list, in the form (before, after)
-			var dependencies = details.Generators
+			var afterGenerators = details.Generators
 				.Select(g => g.generatorType)
-				.SelectMany(t => t.GetCustomAttributes<SourceGeneratorDependencyAttribute>()
-					.Select(a => a.DependsOn)
+				.SelectMany(t => t.GetCustomAttributes<GenerateAfterAttribute>()
+					.Select(a => a.GeneratorToExecuteBefore)
 					.Intersect(generatorNames, StringComparer.InvariantCultureIgnoreCase)
-					.Select(dependency => ((string incoming, string outgoing)) (t.FullName, dependency)))
+					.Select(dependency => ((string incoming, string outgoing)) (t.FullName, dependency)));
+
+			var beforeGenerators = details.Generators
+				.Select(g => g.generatorType)
+				.SelectMany(t => t.GetCustomAttributes<GenerateBeforeAttribute>()
+					.Select(a => a.GeneratorToExecuteAfter)
+					.Intersect(generatorNames, StringComparer.InvariantCultureIgnoreCase)
+					.Select(dependent => ((string incoming, string outgoing))(dependent, t.FullName)));
+
+			var dependencies = afterGenerators.Concat(beforeGenerators)
 				.Where(x => x.incoming != x.outgoing)
 				.Distinct()
 				.ToList();
 
+			if (dependencies.Any())
+			{
+				this.Log().Info($"Generators Ordering restrictions:\n\t{dependencies.Select(d => $"{d.incoming} -> {d.outgoing}").JoinBy("\n\t")}");
+			}
+
 			var groupedGenerators = generatorNames.GroupSort(dependencies);
 
 			if (groupedGenerators == null)
 			{
-				this.Log().Error($"There is a cyclic dependency in the generators:\n\t{dependencies.Select(d => $"{d.incoming} -> {d.outgoing}").JoinBy("\n\t")}");
+				this.Log().Error("There is a cyclic ordering in the generators. You need to fix it. You may need to set your build output to 'normal' to see dependencies list.");
 				return new string[0];
 			}
 
 			if (dependencies.Any())
 			{
-				this.Log().Info($"Generators Dependencies:\n\t{dependencies.Select(d => $"{d.incoming} -> {d.outgoing}").JoinBy("\n\t")}");
+				this.Log().Info($"**Generators Execution Plan**\n\tConcurrently: {groupedGenerators.Select(grp=>grp.JoinBy(", ")).JoinBy("\n\tFollowed by: ")}");
 			}
 
 			// Run
 			var output = new List<string>();
 			(string filePath, string content)[] generatedFilesAndContent = null;
 
+			//Debugger.Launch();
+
 			foreach (var group in groupedGenerators)
 			{
 				if (generatedFilesAndContent != null)

src/Uno.SourceGenerator.sln

@@ -32,6 +32,12 @@ Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Uno.SampleProject.UWP", "Un
 		{D45247E2-A279-472C-8D8B-CBCB83F37FB1} = {D45247E2-A279-472C-8D8B-CBCB83F37FB1}
 	EndProjectSection
 EndProject
+Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "Doc", "Doc", "{DEB6C3E9-CC58-4925-B635-083634263ABC}"
+	ProjectSection(SolutionItems) = preProject
+		..\readme.md = ..\readme.md
+		..\doc\using sourcegenerators.md = ..\doc\using sourcegenerators.md
+	EndProjectSection
+EndProject
 Global
 	GlobalSection(SharedMSBuildProjectFiles) = preSolution
 		Uno.SourceGenerationHost.Shared\Uno.SourceGenerationHost.Shared.projitems*{0a1cc471-6080-415f-8947-e41d8534395e}*SharedItemsImports = 4