Support Common output via BuildDir and PublishDir

Promote PublishDir to BuildDir status
Use BuildDir to initialize MSBuildProjectExtensionsPath
Use BuildDir for mismatch warning instead of BaseIntermediateOutputPath

src/Tasks/Microsoft.Common.CurrentVersion.targets

@@ -105,6 +105,10 @@ Copyright (C) Microsoft Corporation. All rights reserved.
     Several properties must be set in the main project file, before using this .TARGETS file.
     However, if the properties are not set, we pick some defaults.
 
+    BuildDir:
+    Indicates the final output location for the project or solution.
+    All the *OutpuPath properties should derive from this.
+
     OutDir:
     Indicates the final output location for the project or solution. When building a solution,
     OutDir can be used to gather multiple project outputs in one location. In addition,
@@ -142,6 +146,8 @@ Copyright (C) Microsoft Corporation. All rights reserved.
     <_OutputPathWasMissing Condition="'$(_OriginalPlatform)' != '' and '$(_OriginalConfiguration)' != '' and '$(OutputPath)' == ''">true</_OutputPathWasMissing>
     <!-- Check whether BaseOutputPath was specified -->
     <BaseOutputPathWasSpecified Condition="'$(BaseOutputPath)' != ''">true</BaseOutputPathWasSpecified>
+    <!-- Initialize BuildDir when empty, to ensure build doesn't produce inconsistent paths -->
+    <BuildDir>$([MSBuild]::EnsureTrailingSlash($([MSBuild]::ValueOrDefault('$(BuildDir)', 'build'))))</BuildDir>
   </PropertyGroup>
 
   <PropertyGroup>
@@ -150,12 +156,12 @@ Copyright (C) Microsoft Corporation. All rights reserved.
     <Configuration Condition="'$(Configuration)' == ''">Debug</Configuration>
     <ConfigurationName Condition="'$(ConfigurationName)' == ''">$(Configuration)</ConfigurationName>
 
-    <BaseOutputPath>$([MSBuild]::EnsureTrailingSlash($([MSBuild]::ValueOrDefault('$(BaseOutputPath)', 'bin'))))</BaseOutputPath>
+    <BaseOutputPath>$([MSBuild]::EnsureTrailingSlash($([MSBuild]::ValueOrDefault('$(BaseOutputPath)', '$(BuildDir)bin'))))</BaseOutputPath>
     <OutputPath Condition="'$(OutputPath)' == '' and '$(PlatformName)' == 'AnyCPU'">$([System.IO.Path]::Combine('$(BaseOutputPath)', '$(Configuration)'))</OutputPath>
     <OutputPath Condition="'$(OutputPath)' == '' and '$(PlatformName)' != 'AnyCPU'">$([System.IO.Path]::Combine('$(BaseOutputPath)', '$(PlatformName)', '$(Configuration)'))</OutputPath>
     <OutputPath>$([MSBuild]::EnsureTrailingSlash('$(OutputPath)'))</OutputPath>
 
-    <BaseIntermediateOutputPath>$([MSBuild]::EnsureTrailingSlash($([MSBuild]::ValueOrDefault('$(BaseIntermediateOutputPath)', 'obj'))))</BaseIntermediateOutputPath>
+    <BaseIntermediateOutputPath>$([MSBuild]::EnsureTrailingSlash($([MSBuild]::ValueOrDefault('$(BaseIntermediateOutputPath)', '$(BuildDir)obj'))))</BaseIntermediateOutputPath>
     <IntermediateOutputPath Condition="'$(IntermediateOutputPath)' == '' and '$(PlatformName)' == 'AnyCPU'">$([System.IO.Path]::Combine('$(BaseIntermediateOutputPath)', '$(Configuration)'))</IntermediateOutputPath>
     <IntermediateOutputPath Condition="'$(IntermediateOutputPath)' == '' and '$(PlatformName)' != 'AnyCPU'">$([System.IO.Path]::Combine('$(BaseIntermediateOutputPath)', '$(PlatformName)', '$(Configuration)'))</IntermediateOutputPath>
     <IntermediateOutputPath>$([MSBuild]::EnsureTrailingSlash('$(IntermediateOutputPath)'))</IntermediateOutputPath>
@@ -476,7 +482,7 @@ Copyright (C) Microsoft Corporation. All rights reserved.
 
   <!-- Output location for publish target. -->
   <PropertyGroup>
-    <PublishDir>$([MSBuild]::EnsureTrailingSlash($([MSBuild]::ValueOrDefault('$(PublishDir)', '$(OutputPath)app.publish'))))</PublishDir>
+    <PublishDir>$([MSBuild]::EnsureTrailingSlash($([MSBuild]::ValueOrDefault('$(PublishDir)', 'publish'))))</PublishDir>
   </PropertyGroup>
 
   <!--
@@ -839,17 +845,16 @@ Copyright (C) Microsoft Corporation. All rights reserved.
 
     <!--
       Log a warning if:
-        1. $(EnableBaseIntermediateOutputPathMismatchWarning) is 'true'
-        2. $(BaseIntermediateOutputPath) was set in the body of a project after its default value was set in Microsoft.Common.props
-        3. $(BaseIntermediateOutputPath) is not the same as $(MSBuildProjectExtensionsPath)
+        1. $(EnableBuildDirMismatchWarning) is 'true'
+        2. $(BuildDir) was set in the body of a project after its default value was set in Microsoft.Common.props
+        3. $(BuildDir) is not the same as $(MSBuildProjectExtensionsPath)
 
-      Similar to the error above, there are cases when users set $(BaseIntermediateOutputPath) in the body of their project and things build but only by coincidence.
-      MSBuild does not know if $(BaseIntermediateOutputPath) changing would cause problems so tools like NuGet must set $(EnableBaseIntermediateOutputPathMismatchWarning)
-      to 'true'.
+      Similar to the error above, there are cases when users set $(BuildDir) in the body of their project and things build but only by coincidence.
+      MSBuild does not know if $(BuildDir) changing would cause problems so tools like NuGet must set $(EnableBuildDirMismatchWarning) to 'true'.
     -->
-    <Warning Condition=" '$(EnableBaseIntermediateOutputPathMismatchWarning)' == 'true' And '$(_InitialBaseIntermediateOutputPath)' != '$(BaseIntermediateOutputPath)' And '$(BaseIntermediateOutputPath)' != '$(MSBuildProjectExtensionsPath)' "
+    <Warning Condition=" '$(EnableBuildDirMismatchWarning)' == 'true' And '$(_InitialBuildDir)' != '$(BuildDir)' And '$(BuildDir)' != '$(MSBuildProjectExtensionsPath)' "
              Code="MSB3539"
-             Text="The value of the property &quot;BaseIntermediateOutputPath&quot; was modified after it was used by MSBuild which can lead to unexpected build results. Tools such as NuGet will write outputs to the path specified by the &quot;MSBuildProjectExtensionsPath&quot; instead. To set this property, you must do so before Microsoft.Common.props is imported, for example by using Directory.Build.props.  For more information, please visit https://go.microsoft.com/fwlink/?linkid=869650"
+             Text="The value of the property &quot;BuildDir&quot; was modified after it was used by MSBuild which can lead to unexpected build results. Tools such as NuGet will write outputs to the path specified by the &quot;MSBuildProjectExtensionsPath&quot; instead. To set this property, you must do so before Microsoft.Common.props is imported, for example by using Directory.Build.props.  For more information, please visit https://go.microsoft.com/fwlink/?linkid=869650"
              />
   </Target>
 
@@ -5471,7 +5476,7 @@ Copyright (C) Microsoft Corporation. All rights reserved.
 
     <RemoveDir
         Directories="$(PublishDir)"
-        Condition="'$(PublishDir)'=='$(OutputPath)app.publish\' and Exists('$(PublishDir)')"/>
+        Condition="'$(PublishDir)' == '$([MSBuild]::EnsureTrailingSlash(`publish`))' and Exists('$(PublishDir)')"/>
 
   </Target>
 

src/Tasks/Microsoft.Common.props

@@ -33,12 +33,12 @@ Copyright (C) Microsoft Corporation. All rights reserved.
   <Import Project="$(DirectoryBuildPropsPath)" Condition="'$(ImportDirectoryBuildProps)' == 'true' and exists('$(DirectoryBuildPropsPath)')"/>
 
   <!--
-      The declaration of $(BaseIntermediateOutputPath) had to be moved up from Microsoft.Common.CurrentVersion.targets
-      in order for the $(MSBuildProjectExtensionsPath) to use it as a default.
+      The $(BuildDir) replaces $(BaseIntermediateOutputPath) to enable common root output path across multiple projects
+      and for the $(MSBuildProjectExtensionsPath) to use it as a default.
   -->
   <PropertyGroup>
-    <BaseIntermediateOutputPath>$([MSBuild]::EnsureTrailingSlash($([MSBuild]::ValueOrDefault('$(BaseIntermediateOutputPath)', 'obj'))))</BaseIntermediateOutputPath>
-    <_InitialBaseIntermediateOutputPath>$(BaseIntermediateOutputPath)</_InitialBaseIntermediateOutputPath>
+    <BuildDir>$([MSBuild]::EnsureTrailingSlash($([MSBuild]::ValueOrDefault('$(BuildDir)', 'build'))))</BuildDir>
+    <_InitialBuildDir>$(BuildDir)</_InitialBuildDir>
   </PropertyGroup>
 
   <!--
@@ -49,10 +49,10 @@ Copyright (C) Microsoft Corporation. All rights reserved.
       management system can write out multiple files but the order of the import is alphabetic because MSBuild sorts the list.
   -->
   <PropertyGroup>
-    <MSBuildProjectExtensionsPath>$([MSBuild]::EnsureTrailingSlash($([MSBuild]::ValueOrDefault('$(MSBuildProjectExtensionsPath)', '$(BaseIntermediateOutputPath)'))))</MSBuildProjectExtensionsPath>
+    <MSBuildProjectExtensionsPath>$([MSBuild]::EnsureTrailingSlash($([MSBuild]::ValueOrDefault('$(MSBuildProjectExtensionsPath)', '$(BuildDir)'))))</MSBuildProjectExtensionsPath>
     <!--
         Import paths that are relative default to be relative to the importing file.  However, since MSBuildExtensionsPath
-        defaults to BaseIntermediateOutputPath we expect it to be relative to the project directory.  So if the path is relative
+        defaults to BuildDir we expect it to be relative to the project directory.  So if the path is relative
         it needs to be made absolute based on the project directory.
     -->
     <MSBuildProjectExtensionsPath Condition="!$([System.IO.Path]::IsPathRooted('$(MSBuildProjectExtensionsPath)'))">$([MSBuild]::NormalizeDirectory('$(MSBuildProjectDirectory)', '$(MSBuildProjectExtensionsPath)'))</MSBuildProjectExtensionsPath>