Don't use Targets* helper properties in libs (#64500)

* Don't use Targets* helper properties in libs projs

This change makes it possible to migrate 200+ (ref+src) projects to use
TargetFramework instead of TargetFrameworks which avoids the additional
outer build evaluation and invocation which ultimately makes the overall
build faster.

Targets* properties (i.e. TargetsWindows, TargetsAnyOS, TargetsUnix,
etc.) rely on the TargetFramework property which usually are set
inside a project. The TargetFramework property is only
available before a project specifies it if it's explicitly set in a props
file or if the project is cross-targeting and the outer-build dispatches
into the inner-build. During the dispatch, the TargetFramework property
is passed in as a global property.

Until now that behavior wasn't a problem because every libraries project
cross-targeted (by setting the TargetFrameworks property) even though
many only include a single TargetFramework (i.e. NetCoreAppCurrent).

To allow projects to use the TargetFramework property instead of
TargetFrameworks, the Targets* helper properties can't be calculated
anymore early in a props file as the TargetFramework property isn't set
at that time.

In general, the guidance by the SDK/msbuild team is to not read from the
TargetFramework property before the project sets it
(in a property group). That effectively means that the TargetFramework
property shouldn't be used in props files at all.

Therefore these helper properties can't be used anymore for property
conditions and I'm replacing their usage with TargetPlatformIdentifier
comparisons for both properties and items.
In nearly all cases, the Targets* helper properties can be replaced with
TargetPlatformIdentifier checks on items and in the few cases where
TargetsUnix or TargetsLinux marks multiple tfms as compatible, the exact
tfms must be used instead for the TargetPlatformIdentifier comparison.

Whenever a project needs to condition properties on the platform, I'm
first setting the TargetPlatformIdentifier the same way the SDK sets it
so that the SDK later doesn't need to set it again to avoid the
additional expensive msbuild function call.

* Use TargetFramework singular to avoid outer builds

Use TargetFramework instead of TargetFrameworks property whenever a
projects only targets a single target framework. This avoid unnecessary
outer builds and evaluations and makes the build faster.

Directory.Build.props

@@ -305,5 +305,6 @@
   <PropertyGroup>
     <CustomBeforeNoTargets>$(RepositoryEngineeringDir)NoTargetsSdk.BeforeTargets.targets</CustomBeforeNoTargets>
     <CustomAfterTraversalProps>$(RepositoryEngineeringDir)TraversalSdk.AfterProps.props</CustomAfterTraversalProps>
+    <CustomAfterTraversalTargets>$(RepositoryEngineeringDir)TraversalSdk.AfterTargets.targets</CustomAfterTraversalTargets>
   </PropertyGroup>
 </Project>

docs/coding-guidelines/project-guidelines.md

@@ -22,7 +22,7 @@ Below is a list of all the various options we pivot the project builds on:
 ## Individual build properties
 The following are the properties associated with each build pivot
 
-- `$(BuildTargetFramework) -> Any .NETCoreApp or .NETFramework TFM, e.g. net5.0`
+- `$(BuildTargetFramework) -> Any .NETCoreApp or .NETFramework TFM, e.g. net7.0`
 - `$(TargetOS) -> Windows | Linux | OSX | FreeBSD | [defaults to running OS when empty]`
 - `$(Configuration) -> Release | [defaults to Debug when empty]`
 - `$(TargetArchitecture) - x86 | x64 | arm | arm64 | [defaults to x64 when empty]`
@@ -37,22 +37,18 @@ Each project will define a set of supported TargetFrameworks
 <PropertyGroup>
 ```
 
-- `$(BuildSettings) -> $(BuildTargetFramework)[-$(TargetOS)][-$(Configuration)][-$(TargetArchitecture)]`
- - Note this property should be file path safe and thus can be used in file names or directories that need to a unique path for a project configuration.
- - The only required Build Settings value is the `$(BuildTargetFramework)` the others are optional.
-
 Example:
-Pure netstandard configuration:
+Non cross-targeting project that targets .NETStandard:
 ```
 <PropertyGroup>
-  <TargetFrameworks>netstandard2.0</TargetFrameworks>
+  <TargetFramework>netstandard2.0</TargetFramework>
 <PropertyGroup>
 ```
 
-All supported targets with unique windows/unix build for netcoreapp:
+A cross-targeting project which targets specific platform with `$(NetCoreAppCurrent)` and one .NETFramework tfm:
 ```
 <PropertyGroup>
-  <TargetFrameworks>$(NetCoreAppCurrent)-windows;$(NetCoreAppCurrent)-Unix;$(NetFrameworkCurrent)</TargetFrameworks>
+  <TargetFrameworks>$(NetCoreAppCurrent)-windows;$(NetCoreAppCurrent)-Unix;$(NetFrameworkMinimum)</TargetFrameworks>
 <PropertyGroup>
 ```
 
@@ -61,15 +57,15 @@ All supported targets with unique windows/unix build for netcoreapp:
 A full or individual project build is centered around BuildTargetFramework, TargetOS, Configuration and TargetArchitecture.
 
 1. `$(BuildTargetFramework), $(TargetOS), $(Configuration), $(TargetArchitecture)` can individually be passed in to change the default values.
-2. If nothing is passed to the build then we will default value of these properties from the environment. Example: `net5.0-[TargetOS Running On]-Debug-x64`.
-3. While Building an individual project from the VS, we build the project for all latest netcoreapp target frameworks.
+2. If nothing is passed to the build then we will default value of these properties from the environment. Example: `net7.0-[TargetOS Running On]-Debug-x64`.
+3. When building an individual project (either from the CLI or an IDE), all target frameworks are built.
 
 We also have `RuntimeOS` which can be passed to customize the specific OS and version needed for native package builds as well as package restoration. If not passed it will default based on the OS you are running on.
 
-Any of the mentioned properties can be set via `/p:<Property>=<Value>` at the command line. When building using our run tool or any of the wrapper scripts around it (i.e. build.cmd) a number of these properties have aliases which make them easier to pass (run build.cmd/sh -? for the aliases).
+Any of the mentioned properties can be set via `/p:<Property>=<Value>` at the command line. When building using any of the wrapper scripts around it (i.e. build.cmd) a number of these properties have aliases which make them easier to pass (run build.cmd/sh -? for the aliases).
 
 ## Selecting the correct BuildSettings
-When building an individual project the `BuildTargetFramework` and `TargetOS` will be used to select the closest matching TargetFramework listed in the projects `TargetFrameworks` property. The rules used to select the targetFramework will consider compatible target frameworks and OS fallbacks.
+When building an individual project the `BuildTargetFramework` and `TargetOS` will be used to select the compatible dependencies which are expressed as ProjectReference items.
 
 ## Supported full build settings
 - .NET Core latest on current OS (default) -> `$(NetCoreAppCurrent)-[RunningOS]`
@@ -80,37 +76,64 @@ When building an individual project the `BuildTargetFramework` and `TargetOS` wi
 ## TargetFramework conditions
 `TargetFramework` conditions should be avoided in the first PropertyGroup as that causes DesignTimeBuild issues: https://github.com/dotnet/project-system/issues/6143
 
-1. Use an equality check if the TargetFramework isn't overloaded with the OS portion.
+1. Use TargetFrameworkIdentifier to condition on an entire framework to differentiate between .NETCoreApp, .NETStandard and .NETFramework.
+Example:
+```
+<PropertyGroup>
+  <TargetFrameworks>$(NetCoreAppCurrent);netstandard2.0;$(NetFrameworkMinimum)</TargetFrameworks>
+</PropertyGroup>
+<ItemGroup Condition="'$(TargetFrameworkIdentifier)' == '.NETCoreApp'">...</ItemGroup>
+<ItemGroup Condition="'$(TargetFrameworkIdentifier)' == '.NETStandard'">...</ItemGroup>
+<ItemGroup Condition="'$(TargetFrameworkIdentifier)' == '.NETFramework'">...</ItemGroup>
+```
+2. Use equality checks if you want to condition on specific runtime agnostic target frameworks (i.e. without the `-windows` suffix).
 Example:
 ```
 <PropertyGroup>
-  <TargetFrameworks>netstandard2.0;netstandard2.1</TargetFrameworks>
+  <TargetFrameworks>$(NetCoreAppCurrent);netstandard2.0;$(NetFrameworkMinimum)</TargetFrameworks>
 </PropertyGroup>
+<ItemGroup Condition="'$(TargetFramework)' == '$(NetCoreAppCurrent)'">...</ItemGroup>
 <ItemGroup Condition="'$(TargetFramework)' == 'netstandard2.0'">...</ItemGroup>
+<ItemGroup Condition="'$(TargetFramework)' == '$(NetFrameworkMinimum)'">...</ItemGroup>
 ```
-2. Use a StartsWith when you want to test for multiple .NETStandard or .NETFramework versions.
+3. Use the `TargetPlatformIdentifier` property to condition on a .NETCoreApp platform specific target framework. Note that .NETStandard and .NETFramework target frameworks can't be platform specific.
 Example:
 ```
 <PropertyGroup>
-  <TargetFrameworks>netstandard2.0;netstandard2.1</TargetFrameworks>
+  <TargetFrameworks>$(NetCoreAppCurrent)-windows;$(NetCoreAppCurrent)-OSX;$(NetCoreAppCurrent)</TargetFrameworks>
+</PropertyGroup>
+<ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'windows'">...</ItemGroup>
+<ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'OSX'">...</ItemGroup>
+```
+Important: In contrast to the old `Targets*` checks, `TargetPlatformIdentifier` conditions apply to a single tfm only, inheritance between target frameworks can't be expressed. See the example below for Unix:
+```
+<PropertyGroup>
+  <TargetFrameworks>$(NetCoreAppCurrent)-Unix;$(NetCoreAppCurrent)-Linux;$(NetCoreAppCurrent)-android;$(NetCoreAppCurrent)-windows</TargetFrameworks>
 </PropertyGroup>
-<ItemGroup Condition="$(TargetFramework.StartsWith('netstandard'))>...</ItemGroup>
+<ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'Unix' or '$(TargetPlatformIdentifier)' == 'Linux' or '$(TargetPlatformIdentifier)' == 'android'">...</ItemGroup>
+<!-- Negations make such conditions easier to write and read. -->
+<ItemGroup Condition="'$(TargetPlatformIdentifier)' != 'windows'">...</ItemGroup>
 ```
-3. Use a StartsWith if the TargetFramework is overloaded with the OS portion.
+4. Set the `TargetPlatformIdentifier` property in the project to be able to condition on it in properties in the project file.
+That is necessary as the SDK sets the `TargetPlatformIdentifier` in a .targets file after the project is evaluated. Because of that, the property isn't available during the project's evaluation and must be set manually.
 Example:
 ```
 <PropertyGroup>
-  <TargetFrameworks>netstandard2.0-windows;netstandard2.0-Unix</TargetFrameworks>
+  <TargetFrameworks>$(NetCoreAppCurrent)-windows;$(NetCoreAppCurrent)-android</TargetFrameworks>
+</PropertyGroup>
+<!-- DesignTimeBuild requires all the TargetFramework Derived Properties to not be present in the first property group. -->
+<PropertyGroup>
+  <TargetPlatformIdentifier>$([MSBuild]::GetTargetPlatformIdentifier('$(TargetFramework)'))</TargetPlatformIdentifier>
+  <DefineConstants Condition="'$(TargetPlatformIdentifier)' == 'android'">$(DefineConstants);ANDROID_USE_BUFFER</DefineConstants>
 </PropertyGroup>
-<ItemGroup Condition="$(TargetFramework.StartsWith('netstandard2.0'))>...</ItemGroup>
 ```
-4. Use negations if that makes the conditions easier.
+5. Use negations if that makes the conditions easier.
 Example:
 ```
 <PropertyGroup>
-  <TargetFrameworks>netstandard2.0;net462;net472;net5.0</TargetFrameworks>
+  <TargetFrameworks>$(NetCoreAppCurrent);netstandard2.0;net462</TargetFrameworks>
 </PropertyGroup>
-<ItemGroup Condition="!$(TargetFramework.StartsWith('net4'))>...</ItemGroup>
+<ItemGroup Condition="'$(TargetFrameworkIdentifier)' != '.NETFramework'">...</ItemGroup>
 <ItemGroup Condition="'$(TargetFramework)' != 'netstandard2.0'">...</ItemGroup>
 ```
 
@@ -119,11 +142,10 @@ Example:
 Library projects should use the following directory layout.
 
 ```
-src\<Library Name>\src - Contains the source code for the library.
+src\<Library Name>\gen - Contains source code for the assembly's source generator.
 src\<Library Name>\ref - Contains any reference assembly projects for the library.
-src\<Library Name>\pkg - Contains package projects for the library.
+src\<Library Name>\src - Contains the source code for the library.
 src\<Library Name>\tests - Contains the test code for a library.
-src\<Library Name>\gen - Contains source code for the assembly's source generator.
 ```
 
 ## ref

eng/BeforeTargetFrameworkInference.targets

@@ -1,5 +1,22 @@
 <Project>
 
-  <Import Project="$(MSBuildThisDirectory)targetframeworksuffix.props" Condition="'$(DesignTimeBuild)' == 'true'" />
+  <PropertyGroup>
+    <TargetPlatformSupported>true</TargetPlatformSupported>
+    <TargetPlatformVersionSupported>true</TargetPlatformVersionSupported>
+
+    <!-- Value of 0.0 produces versionless SupportedOSPlatform attribute.
+         This is required for platforms not expected to have a version,
+         and we currently omit the version for all platforms. -->
+    <SupportedOSPlatformVersion>0.0</SupportedOSPlatformVersion>
+
+    <!-- Disable setting a default Windows platform for .NETStandard and .NET Framework libraries.
+         This ensures that the TargetPlatformIdentifier property is empty for non .NETCoreApp tfms. -->
+    <_EnableDefaultWindowsPlatform>false</_EnableDefaultWindowsPlatform>
+    <_targetPlatformIdentifier Condition="$(TargetFramework.Contains('-'))">$(TargetFramework.SubString($([MSBuild]::Add($(TargetFramework.IndexOf('-')), 1))))</_targetPlatformIdentifier>
+  </PropertyGroup>
+
+  <PropertyGroup Condition="'$(_targetPlatformIdentifier)' != '' and '$(_targetPlatformIdentifier)' != 'windows'">
+    <TargetPlatformVersion>1.0</TargetPlatformVersion>
+  </PropertyGroup>
 
 </Project>

eng/TraversalSdk.AfterTargets.targets

@@ -0,0 +1,18 @@
+<Project>
+
+  <!-- Uses the Microsoft.DotNet.Build.Tasks.TargetFramework package to filter out target frameworks from ProjectReferences. -->
+  <PropertyGroup Condition="'$(FilterTraversalProjectReferences)' == 'true'">
+    <BuildDependsOn>$(BuildDependsOn);ResolveP2PReferences</BuildDependsOn>
+    <CleanDependsOn>$(CleanDependsOn);ResolveP2PReferences</CleanDependsOn>
+    <RebuildDependsOn>$(RebuildDependsOn);ResolveP2PReferences</RebuildDependsOn>
+    <TestDependsOn>$(TestDependsOn);ResolveP2PReferences</TestDependsOn>
+    <VSTestDependsOn>$(VSTestDependsOn);ResolveP2PReferences</VSTestDependsOn>
+    <PackDependsOn>$(PackDependsOn);ResolveP2PReferences</PackDependsOn>
+    <PublishDependsOn>$(PublishDependsOn);ResolveP2PReferences</PublishDependsOn>
+  </PropertyGroup>
+
+  <ItemGroup Condition="'$(FilterTraversalProjectReferences)' == 'true'">
+    <ProjectReference Update="@(ProjectReference)" SkipGetTargetFrameworkProperties="false" />
+  </ItemGroup>
+
+</Project>

eng/Version.Details.xml

@@ -102,9 +102,9 @@
       <Uri>https://github.com/dotnet/arcade</Uri>
       <Sha>78eaf78761027d225030be2b28aaf4e8bf392929</Sha>
     </Dependency>
-    <Dependency Name="Microsoft.DotNet.Build.Tasks.TargetFramework" Version="7.0.0-beta.22110.7">
+    <Dependency Name="Microsoft.DotNet.Build.Tasks.TargetFramework" Version="7.0.0-beta.22111.10">
       <Uri>https://github.com/dotnet/arcade</Uri>
-      <Sha>78eaf78761027d225030be2b28aaf4e8bf392929</Sha>
+      <Sha>ff6cc4e9c3eef575f62a33a642ca80e79d27c9bb</Sha>
     </Dependency>
     <Dependency Name="Microsoft.DotNet.RemoteExecutor" Version="7.0.0-beta.22110.7">
       <Uri>https://github.com/dotnet/arcade</Uri>

eng/Versions.props

@@ -67,7 +67,7 @@
     <MicrosoftDotNetBuildTasksArchivesVersion>7.0.0-beta.22110.7</MicrosoftDotNetBuildTasksArchivesVersion>
     <MicrosoftDotNetBuildTasksInstallersVersion>7.0.0-beta.22110.7</MicrosoftDotNetBuildTasksInstallersVersion>
     <MicrosoftDotNetBuildTasksPackagingVersion>7.0.0-beta.22110.7</MicrosoftDotNetBuildTasksPackagingVersion>
-    <MicrosoftDotNetBuildTasksTargetFrameworkVersion>7.0.0-beta.22110.7</MicrosoftDotNetBuildTasksTargetFrameworkVersion>
+    <MicrosoftDotNetBuildTasksTargetFrameworkVersion>7.0.0-beta.22111.10</MicrosoftDotNetBuildTasksTargetFrameworkVersion>
     <MicrosoftDotNetBuildTasksTemplatingVersion>7.0.0-beta.22110.7</MicrosoftDotNetBuildTasksTemplatingVersion>
     <MicrosoftDotNetBuildTasksWorkloadsPackageVersion>7.0.0-beta.22110.7</MicrosoftDotNetBuildTasksWorkloadsPackageVersion>
     <MicrosoftDotNetRemoteExecutorVersion>7.0.0-beta.22110.7</MicrosoftDotNetRemoteExecutorVersion>

eng/packaging.targets

@@ -10,9 +10,9 @@
     <PackDependsOn>AddNETStandardCompatErrorFileForPackaging;IncludeAnalyzersInPackage;$(PackDependsOn)</PackDependsOn>
     <BeforePack>AddNETStandardCompatErrorFileForPackaging;IncludeAnalyzersInPackage;$(BeforePack)</BeforePack>
     <TargetsForTfmSpecificContentInPackage>$(TargetsForTfmSpecificContentInPackage);AddRuntimeSpecificFilesToPackage;IncludeProjectReferencesWithPackAttributeInPackage</TargetsForTfmSpecificContentInPackage>
-    <IncludeBuildOutput Condition="'$(TargetFrameworkIdentifier)' == '.NETCoreApp' and '$(TargetPlatformIdentifier)' != ''">false</IncludeBuildOutput>
+    <IncludeBuildOutput Condition="'$(TargetPlatformIdentifier)' != ''">false</IncludeBuildOutput>
     <!-- Don't include target platform specific dependencies, since we use the target platform to represent RIDs instead -->
-    <SuppressDependenciesWhenPacking Condition="'$(TargetFrameworkIdentifier)' == '.NETCoreApp' and '$(TargetPlatformIdentifier)' != ''">true</SuppressDependenciesWhenPacking>
+    <SuppressDependenciesWhenPacking Condition="'$(TargetPlatformIdentifier)' != ''">true</SuppressDependenciesWhenPacking>
     <PackageDesignerMarkerFile>$(MSBuildThisFileDirectory)useSharedDesignerContext.txt</PackageDesignerMarkerFile>
     <!-- Generate packages for rid specific projects or for allconfigurations during build. -->
     <!-- A package isn't generated if in servicing or in runtimelab. Intended to be overridden at project level. -->
@@ -101,7 +101,7 @@
                             DocumentationProjectOutputGroup;
                             SatelliteDllsProjectOutputGroup;
                             $(TargetsForTfmSpecificBuildOutput)"
-          Condition="'$(TargetFrameworkIdentifier)' == '.NETCoreApp' and '$(TargetPlatformIdentifier)' != ''">
+          Condition="'$(TargetPlatformIdentifier)' != ''">
     <PropertyGroup>
       <RuntimeSymbolPath>$(TargetDir)$(TargetName).pdb</RuntimeSymbolPath>
       <_packageTargetRuntime>$(TargetPlatformIdentifier.ToLowerInvariant().Replace('windows', 'win'))</_packageTargetRuntime>