Change linker to trim everything by default in 7.0

eng/Version.Details.xml

@@ -125,19 +125,19 @@
       <Uri>https://github.com/microsoft/vstest</Uri>
       <Sha>b1452a516a80672fa814f4ebdf2151c0875d0b20</Sha>
     </Dependency>
-    <Dependency Name="Microsoft.NET.ILLink.Tasks" Version="7.0.100-1.22354.1">
+    <Dependency Name="Microsoft.NET.ILLink.Tasks" Version="7.0.100-1.22357.2">
       <Uri>https://github.com/dotnet/linker</Uri>
-      <Sha>ef2d0f25b72469b55925251a79f12bcbf98644bf</Sha>
+      <Sha>b6f1fb4d67f6aab530382e1973b898ba858709e0</Sha>
       <SourceBuild RepoName="linker" ManagedOnly="true" />
     </Dependency>
     <Dependency Name="Microsoft.DotNet.ILCompiler" Version="7.0.0-preview.6.22356.1">
       <Uri>https://github.com/dotnet/runtime</Uri>
       <Sha>206dccb7945aaa3f26599fbe742de9022ca7ef91</Sha>
       <SourceBuildTarball RepoName="runtime" ManagedOnly="true" />
     </Dependency>
-    <Dependency Name="Microsoft.NET.ILLink.Analyzers" Version="7.0.100-1.22354.1">
+    <Dependency Name="Microsoft.NET.ILLink.Analyzers" Version="7.0.100-1.22357.2">
       <Uri>https://github.com/dotnet/linker</Uri>
-      <Sha>ef2d0f25b72469b55925251a79f12bcbf98644bf</Sha>
+      <Sha>b6f1fb4d67f6aab530382e1973b898ba858709e0</Sha>
     </Dependency>
     <Dependency Name="System.CodeDom" Version="7.0.0-preview.6.22356.1">
       <Uri>https://github.com/dotnet/runtime</Uri>

eng/Versions.props

@@ -83,7 +83,7 @@
   </PropertyGroup>
   <PropertyGroup>
     <!-- Dependencies from https://github.com/mono/linker -->
-    <MicrosoftNETILLinkTasksPackageVersion>7.0.100-1.22354.1</MicrosoftNETILLinkTasksPackageVersion>
+    <MicrosoftNETILLinkTasksPackageVersion>7.0.100-1.22357.2</MicrosoftNETILLinkTasksPackageVersion>
     <MicrosoftNETILLinkAnalyzerPackageVersion>$(MicrosoftNETILLinkTasksPackageVersion)</MicrosoftNETILLinkAnalyzerPackageVersion>
   </PropertyGroup>
   <PropertyGroup>

src/BlazorWasmSdk/Targets/Microsoft.NET.Sdk.BlazorWebAssembly.Current.props

@@ -29,7 +29,7 @@ Copyright (c) .NET Foundation. All rights reserved.
 
     <!-- Trimmer defaults -->
     <PublishTrimmed Condition="'$(PublishTrimmed)' == ''">true</PublishTrimmed>
-    <TrimMode Condition="'$(TrimMode)' == ''">link</TrimMode>
+    <TrimMode Condition="'$(TrimMode)' == ''">partial</TrimMode>
     <TrimmerRemoveSymbols Condition="'$(TrimmerRemoveSymbols)' == ''">false</TrimmerRemoveSymbols>
 
     <!-- Static web assets defaults -->

src/Tests/Microsoft.NET.Build.Tests/ReferenceExeTests.cs

@@ -29,6 +29,10 @@ public ReferenceExeTests(ITestOutputHelper log) : base(log)
 
         private bool TestWithPublish { get; set; } = false;
 
+        private bool PublishTrimmed = false;
+
+        private bool ReferenceExeInCode = false;
+
         private TestProject MainProject { get; set; }
 
         private TestProject ReferencedProject { get; set; }
@@ -44,10 +48,31 @@ private void CreateProjects()
             };
 
             MainProject.PackageReferences.Add(new TestPackageReference("Humanizer", "2.8.26"));
-            MainProject.SourceFiles["Program.cs"] = @"using Humanizer; System.Console.WriteLine(""MainProject"".Humanize());";
+            var mainProjectSrc = @"
+using System;
+using Humanizer;
+Console.WriteLine(""MainProject"".Humanize());";
+
+            if (PublishTrimmed)
+            {
+                MainProject.AdditionalProperties["PublishTrimmed"] = "true";
+
+                // If we're fully trimming, unless the trimmed project contains an explicit reference in code
+                // to the referenced project, it will get trimmed away
+                if (ReferenceExeInCode)
+                {
+                    mainProjectSrc += @"
+// Always false, but the trimmer doesn't know that
+if (string.Empty.Length > 0)
+{
+    ReferencedExeProgram.Main();
+}";
+
+                }
+            }
 
-            //  By default we don't create the app host on Mac for FDD.  For these tests, we want to create it everywhere
-            MainProject.AdditionalProperties["UseAppHost"] = "true";
+
+            MainProject.SourceFiles["Program.cs"] = mainProjectSrc;
 
             if (MainSelfContained)
             {
@@ -62,16 +87,22 @@ private void CreateProjects()
                 IsExe = true,
             };
 
-            ReferencedProject.AdditionalProperties["UseAppHost"] = "true";
-
             if (ReferencedSelfContained)
             {
                 ReferencedProject.RuntimeIdentifier = EnvironmentInfo.GetCompatibleRid();
             }
 
             //  Use a lower version of a library in the referenced project
             ReferencedProject.PackageReferences.Add(new TestPackageReference("Humanizer", "2.7.9"));
-            ReferencedProject.SourceFiles["Program.cs"] = @"using Humanizer; System.Console.WriteLine(""ReferencedProject"".Humanize());";
+            ReferencedProject.SourceFiles["Program.cs"] = @"
+using Humanizer;
+public class ReferencedExeProgram
+{
+    public static void Main()
+    {
+        System.Console.WriteLine(""ReferencedProject"".Humanize());
+    }
+}";
 
             MainProject.ReferencedProjects.Add(ReferencedProject);
         }
@@ -122,11 +153,23 @@ private void RunTest(string buildFailureCode = null, [CallerMemberName] string c
                 var referencedExeResult = new RunExeCommand(Log, referencedExePath)
                     .Execute();
 
-                referencedExeResult
-                    .Should()
-                    .Pass()
-                    .And
-                    .HaveStdOut("Referenced project");
+                // If we're trimming and didn't reference the exe in source we would expect it to be trimmed from the output
+                if (PublishTrimmed && !ReferenceExeInCode)
+                {
+                    referencedExeResult
+                        .Should()
+                        .Fail()
+                        .And
+                        .HaveStdErrContaining("The application to execute does not exist");
+                }
+                else
+                {
+                    referencedExeResult
+                        .Should()
+                        .Pass()
+                        .And
+                        .HaveStdOut("Referenced project");
+                }
             }
             else
             {
@@ -238,25 +281,20 @@ public void ReferencedExeCanRunWhenPublished(bool selfContained)
             RunTest();
         }
 
-        [Fact]
-        public void ReferencedExeCanRunWhenPublishedWithTrimming()
+        [Theory]
+        [InlineData(true)]
+        [InlineData(false)]
+        public void ReferencedExeCanRunWhenPublishedWithTrimming(bool referenceExeInCode)
         {
             MainSelfContained = true;
             ReferencedSelfContained = true;
 
             TestWithPublish = true;
+            PublishTrimmed = true;
+            ReferenceExeInCode = referenceExeInCode;
 
             CreateProjects();
 
-            if (MainSelfContained)
-            {
-                MainProject.AdditionalProperties["PublishTrimmed"] = "True";
-            }
-            if (ReferencedSelfContained)
-            {
-                ReferencedProject.AdditionalProperties["PublishTrimmed"] = "True";
-            }
-
             RunTest();
         }
 

src/Tests/Microsoft.NET.Publish.Tests/GivenThatWeWantToRunILLink.cs

@@ -23,6 +23,7 @@
 using Xunit;
 using Xunit.Abstractions;
 using static Microsoft.NET.Publish.Tests.PublishTestUtils;
+using System.Security.Permissions;
 
 namespace Microsoft.NET.Publish.Tests
 {
@@ -187,6 +188,10 @@ public void PrepareForILLink_can_set_TrimMode(string targetFramework)
         [RequiresMSBuildVersionTheory("17.0.0.32901")]
         [InlineData("net5.0", "link")]
         [InlineData(ToolsetInfo.CurrentTargetFramework, "copyused")]
+        [InlineData("net6.0", "full")]
+        [InlineData(ToolsetInfo.CurrentTargetFramework, "full")]
+        [InlineData("net6.0", "partial")]
+        [InlineData(ToolsetInfo.CurrentTargetFramework, "partial")]
         public void ILLink_respects_global_TrimMode(string targetFramework, string trimMode)
         {
             var projectName = "HelloWorld";
@@ -210,7 +215,7 @@ public void ILLink_respects_global_TrimMode(string targetFramework, string trimM
             File.Exists(publishedDll).Should().BeTrue();
             File.Exists(isTrimmableDll).Should().BeTrue();
             DoesImageHaveMethod(isTrimmableDll, "UnusedMethodToRoot").Should().BeTrue();
-            if (trimMode == "link") {
+            if (trimMode is "link" or "full" or "partial") {
                 // Check that the assembly was trimmed at the member level
                 DoesImageHaveMethod(isTrimmableDll, "UnusedMethod").Should().BeFalse();
             } else {
@@ -269,7 +274,8 @@ public void ILLink_respects_TrimmableAssembly(string targetFramework)
         }
 
         [RequiresMSBuildVersionTheory("17.0.0.32901")]
-        [MemberData(nameof(Net6Plus), MemberType = typeof(PublishTestUtils))]
+        [InlineData("net6.0")]
+        [InlineData("net7.0")]
         public void ILLink_respects_IsTrimmable_attribute(string targetFramework)
         {
             string projectName = "HelloWorld";
@@ -287,7 +293,16 @@ public void ILLink_respects_IsTrimmable_attribute(string targetFramework)
 
             // Only unused non-trimmable assemblies are kept
             File.Exists(unusedTrimmableDll).Should().BeFalse();
-            DoesImageHaveMethod(unusedNonTrimmableDll, "UnusedMethod").Should().BeTrue();
+            if (targetFramework == "net6.0")
+            {
+                // In net6.0 the default is to keep assemblies not marked trimmable
+                DoesImageHaveMethod(unusedNonTrimmableDll, "UnusedMethod").Should().BeTrue();
+            }
+            else
+            {
+                // In net7.0+ the default is to keep assemblies not marked trimmable
+                File.Exists(unusedNonTrimmableDll).Should().BeFalse();
+            }
         }
 
         [RequiresMSBuildVersionTheory("17.0.0.32901")]
@@ -298,6 +313,7 @@ public void ILLink_IsTrimmable_metadata_can_override_attribute(string targetFram
             var rid = EnvironmentInfo.GetCompatibleRid(targetFramework);
             var testProject = CreateTestProjectWithIsTrimmableAttributes(targetFramework, projectName);
             var testAsset = _testAssetsManager.CreateTestProject(testProject, identifier: targetFramework)
+                .WithProjectChanges(project => SetGlobalTrimMode(project, "partial"))
                 .WithProjectChanges(project => SetMetadata(project, "UnusedTrimmableAssembly", "IsTrimmable", "false"))
                 .WithProjectChanges(project => SetMetadata(project, "UnusedNonTrimmableAssembly", "IsTrimmable", "true"));
 
@@ -316,7 +332,7 @@ public void ILLink_IsTrimmable_metadata_can_override_attribute(string targetFram
         }
 
         [RequiresMSBuildVersionTheory("17.0.0.32901")]
-        [MemberData(nameof(Net6Plus), MemberType = typeof(PublishTestUtils))]
+        [InlineData("net6.0")]
         public void ILLink_TrimMode_applies_to_IsTrimmable_assemblies(string targetFramework)
         {
             string projectName = "HelloWorld";
@@ -343,6 +359,47 @@ public void ILLink_TrimMode_applies_to_IsTrimmable_assemblies(string targetFrame
             DoesImageHaveMethod(unusedNonTrimmableDll, "UnusedMethod").Should().BeTrue();
         }
 
+        [RequiresMSBuildVersionTheory("17.0.0.32901")]
+        [InlineData(ToolsetInfo.CurrentTargetFramework, "full")]
+        [InlineData(ToolsetInfo.CurrentTargetFramework, "partial")]
+        public void ILLink_TrimMode_new_options(string targetFramework, string trimMode)
+        {
+            string projectName = "HelloWorld";
+            var rid = EnvironmentInfo.GetCompatibleRid(targetFramework);
+            var testProject = CreateTestProjectWithIsTrimmableAttributes(targetFramework, projectName);
+            var testAsset = _testAssetsManager.CreateTestProject(testProject, identifier: targetFramework + trimMode)
+                .WithProjectChanges(project => SetGlobalTrimMode(project, trimMode));
+
+            var publishCommand = new PublishCommand(testAsset);
+            publishCommand.Execute($"/p:RuntimeIdentifier={rid}", "-bl").Should().Pass();
+
+            var publishDirectory = publishCommand.GetOutputDirectory(targetFramework: targetFramework, runtimeIdentifier: rid).FullName;
+
+            var trimmableDll = Path.Combine(publishDirectory, "TrimmableAssembly.dll");
+            var nonTrimmableDll = Path.Combine(publishDirectory, "NonTrimmableAssembly.dll");
+            var unusedTrimmableDll = Path.Combine(publishDirectory, "UnusedTrimmableAssembly.dll");
+            var unusedNonTrimmableDll = Path.Combine(publishDirectory, "UnusedNonTrimmableAssembly.dll");
+
+            // Trimmable assemblies are trimmed at member level
+            DoesImageHaveMethod(trimmableDll, "UnusedMethod").Should().BeFalse();
+            DoesImageHaveMethod(trimmableDll, "UsedMethod").Should().BeTrue();
+            File.Exists(unusedTrimmableDll).Should().BeFalse();
+            if (trimMode is "full")
+            {
+                DoesImageHaveMethod(nonTrimmableDll, "UnusedMethod").Should().BeFalse();
+                File.Exists(unusedNonTrimmableDll).Should().BeFalse();
+            }
+            else if (trimMode is "partial")
+            {
+                DoesImageHaveMethod(nonTrimmableDll, "UnusedMethod").Should().BeTrue();
+                DoesImageHaveMethod(unusedNonTrimmableDll, "UnusedMethod").Should().BeTrue();
+            }
+            else
+            {
+                Assert.True(false, "unexpected value");
+            }
+        }
+
         [RequiresMSBuildVersionTheory("17.0.0.32901")]
         [InlineData(ToolsetInfo.CurrentTargetFramework)]
         public void ILLink_can_set_TrimmerDefaultAction(string targetFramework)
@@ -868,8 +925,10 @@ public void ILLink_runs_incrementally(string targetFramework)
         }
 
         [RequiresMSBuildVersionTheory("17.0.0.32901")]
-        [MemberData(nameof(SupportedTfms), MemberType = typeof(PublishTestUtils))]
-        public void ILLink_defaults_keep_nonframework(string targetFramework)
+        [InlineData("netcoreapp3.1")]
+        [InlineData("net5.0")]
+        [InlineData("net6.0")]
+        public void ILLink_old_defaults_keep_nonframework(string targetFramework)
         {
             var projectName = "HelloWorld";
             var referenceProjectName = "ClassLibForILLink";
@@ -903,6 +962,42 @@ public void ILLink_defaults_keep_nonframework(string targetFramework)
             DoesDepsFileHaveAssembly(depsFile, unusedFrameworkAssembly).Should().BeFalse();
         }
 
+        [RequiresMSBuildVersionFact("17.0.0.32901")]
+        public void ILLink_net7_defaults_trim_nonframework()
+        {
+            string targetFramework = "net7.0";
+            var projectName = "HelloWorld";
+            var referenceProjectName = "ClassLibForILLink";
+            var rid = EnvironmentInfo.GetCompatibleRid(targetFramework);
+
+            var testProject = CreateTestProjectForILLinkTesting(targetFramework, projectName, referenceProjectName);
+            var testAsset = _testAssetsManager.CreateTestProject(testProject, identifier: targetFramework);
+
+            var publishCommand = new PublishCommand(testAsset);
+            publishCommand.Execute("/v:n", $"/p:RuntimeIdentifier={rid}", "/p:PublishTrimmed=true").Should().Pass();
+
+            var publishDirectory = publishCommand.GetOutputDirectory(targetFramework: targetFramework, runtimeIdentifier: rid).FullName;
+            var intermediateDirectory = publishCommand.GetIntermediateDirectory(targetFramework: targetFramework, runtimeIdentifier: rid).FullName;
+            var linkedDirectory = Path.Combine(intermediateDirectory, "linked");
+
+            Directory.Exists(linkedDirectory).Should().BeTrue();
+
+            var linkedDll = Path.Combine(linkedDirectory, $"{projectName}.dll");
+            var publishedDll = Path.Combine(publishDirectory, $"{projectName}.dll");
+            var unusedDll = Path.Combine(publishDirectory, $"{referenceProjectName}.dll");
+            var unusedFrameworkDll = Path.Combine(publishDirectory, $"{unusedFrameworkAssembly}.dll");
+
+            File.Exists(linkedDll).Should().BeTrue();
+            File.Exists(publishedDll).Should().BeTrue();
+            File.Exists(unusedDll).Should().BeFalse();
+            File.Exists(unusedFrameworkDll).Should().BeFalse();
+
+            var depsFile = Path.Combine(publishDirectory, $"{projectName}.deps.json");
+            DoesDepsFileHaveAssembly(depsFile, projectName).Should().BeTrue();
+            DoesDepsFileHaveAssembly(depsFile, referenceProjectName).Should().BeFalse();
+            DoesDepsFileHaveAssembly(depsFile, unusedFrameworkAssembly).Should().BeFalse();
+        }
+
         [RequiresMSBuildVersionTheory("17.0.0.32901")]
         [MemberData(nameof(SupportedTfms), MemberType = typeof(PublishTestUtils))]
         public void ILLink_does_not_include_leftover_artifacts_on_second_run(string targetFramework)

src/WebSdk/Publish/Targets/Microsoft.NET.Sdk.Publish.targets

@@ -85,6 +85,9 @@ Copyright (C) Microsoft Corporation. All rights reserved.
     <PublishIntermediateOutputPath Condition="'$(DockerPublish)' == 'true'">obj/Docker/publish/</PublishIntermediateOutputPath>
 
     <EFSQLScriptsFolderName Condition="$(EFSQLScriptsFolderName) == ''">EFSQLScripts</EFSQLScriptsFolderName>
+
+    <!-- If TrimMode has not already been set, default to partial trimming, as AspNet is not currently fully trim-compatible -->
+    <TrimMode Condition="'$(PublishTrimmed)' == 'true' and '$(TrimMode)' == ''">partial</TrimMode>
   </PropertyGroup>
 
   <!--