Fix .cmd scripts help arguments (dotnet#1131)

build.cmd

@@ -1,15 +1,8 @@
 @echo off
+setlocal
 
-if "%~1"=="-h" goto help
-if "%~1"=="-help" goto help
-if "%~1"=="-?" goto help
-if "%~1"=="/?" goto help
+set _args=%*
+if "%~1"=="-?" set _args=-help
 
-powershell -ExecutionPolicy ByPass -NoProfile -File "%~dp0eng\build.ps1" %*
-goto end
-
-:help
-powershell -ExecutionPolicy ByPass -NoProfile -Command "& { . '%~dp0eng\build.ps1'; Get-Help }"
-
-:end
+powershell -ExecutionPolicy ByPass -NoProfile -File "%~dp0eng\build.ps1" %_args%
 exit /b %ERRORLEVEL%

coreclr.cmd

@@ -1,2 +1,7 @@
 @echo off
-"%~dp0build.cmd" -subsetCategory coreclr %*
+setlocal
+
+set _args=-subsetCategory coreclr %*
+if "%~1"=="-?" set _args=-help
+
+"%~dp0build.cmd" %_args%

eng/build.ps1

@@ -1,5 +1,6 @@
 [CmdletBinding(PositionalBinding=$false)]
 Param(
+  [switch][Alias('h')]$help,
   [switch][Alias('b')]$build,
   [switch][Alias('t')]$test,
   [switch]$buildtests,
@@ -57,6 +58,11 @@ if ($MyInvocation.InvocationName -eq ".") {
   exit 0
 }
 
+if ($help -or (($null -ne $properties) -and ($properties.Contains('/help') -or $properties.Contains('/?')))) {
+  Get-Help
+  exit 0
+}
+
 $subsetCategory = $subsetCategory.ToLowerInvariant()
 
 # VS Test Explorer support for libraries

installer.cmd

@@ -1,2 +1,7 @@
 @echo off
-"%~dp0build.cmd" -subsetCategory installer %*
+setlocal
+
+set _args=-subsetCategory installer %*
+if "%~1"=="-?" set _args=-help
+
+"%~dp0build.cmd" %_args%

libraries.cmd

@@ -1,2 +1,7 @@
 @echo off
-"%~dp0build.cmd" -subsetCategory libraries %*
+setlocal
+
+set _args=-subsetCategory libraries %*
+if "%~1"=="-?" set _args=-help
+
+"%~dp0build.cmd" %_args%