Resolve-MSBuild.ps1

<#PSScriptInfo
.VERSION 1.5.1
.AUTHOR Roman Kuzmin
.COPYRIGHT (c) Roman Kuzmin
.TAGS Invoke-Build, MSBuild
.GUID 53c01926-4fc5-4cbd-aa46-32e415b2373b
.LICENSEURI http://www.apache.org/licenses/LICENSE-2.0
.PROJECTURI https://github.com/nightroman/Invoke-Build
#>

<#
.Synopsis
	Finds the specified or latest MSBuild.

.Description
	The script finds the path to the specified or latest version of MSBuild.
	It is designed for MSBuild 16.0, 15.0, 14.0, 12.0, 4.0, 3.5, 2.0.

	For MSBuild 15+ the command uses the module VSSetup, see PSGallery.
	If VSSetup is not installed then the default locations are used.
	VSSetup is required for not default installations.

	MSBuild 15+ resolution: the latest major version (or absolute if -Latest),
	then Enterprise, Professional, Community, BuildTools, other products.

	For MSBuild 2.0-14.0 the information is taken from the registry.

.Parameter Version
		Specifies the required MSBuild major version. If it is omitted, empty,
		or *, then the command finds and returns the latest installed version
		path. The optional suffix x86 tells to use 32-bit MSBuild.
		Known versions: 16.0, 15.0, 14.0, 12.0, 4.0, 3.5, 2.0
.Parameter MinimumVersion
		Specifies the required minimum MSBuild version. If the resolved MSBuild
		version is less than the minimum version then an error is thrown.
.Parameter Latest
		Tells to select the latest minor version if there are 2+ products with
		the same major version. Note that major versions have higher precedence
		than products regardless of -Latest.

.Outputs
	The full path to MSBuild.exe

.Example
	Resolve-MSBuild 16.0x86
	Gets the location of 32-bit MSBuild of Visual Studio 2019.

.Example
	Resolve-MSBuild x86 15.0 -Latest
	Gets the location of the latest 32-bit MSBuild, and asserts that its
	version is at least 15.0.

.Example
	Resolve-MSBuild -MinimumVersion 16.3.1 -Latest
	Gets the location of the latest MSBuild, and asserts that its version is at
	least 16.3.1.

.Link
	https://www.powershellgallery.com/packages/VSSetup
#>

[OutputType([string])]
[CmdletBinding()]
param(
	[string]$Version,
	[Version]$MinimumVersion,
	[switch]$Latest
)

function Get-MSBuild15Path {
	[CmdletBinding()] param(
		[string]$Version,
		[string]$Bitness
	)

	if ([System.IntPtr]::Size -eq 4 -or $Bitness -eq 'x86') {
		"MSBuild\$Version\Bin\MSBuild.exe"
	}
	else {
		"MSBuild\$Version\Bin\amd64\MSBuild.exe"
	}
}

function Get-MSBuild15VSSetup {
	[CmdletBinding()] param(
		[string]$Version,
		[string]$Bitness,
		[switch]$Latest,
		[switch]$Prerelease
	)

	if (!(Get-Module VSSetup)) {
		if (!(Get-Module VSSetup -ListAvailable)) {return}
		Import-Module VSSetup
	}

	$items = @(
		$v = switch($Version) {
			'16.0' {'[16.0,17.0)'}
			'15.0' {'[15.0,16.0)'}
			default {'[15.0,)'}
		}
		Get-VSSetupInstance -Prerelease:$Prerelease |
		Select-VSSetupInstance -Version $v -Require Microsoft.Component.MSBuild -Product *
	)
	if (!$items) {
		if (!$Prerelease) {
			Get-MSBuild15VSSetup $Version $Bitness -Latest:$Latest -Prerelease
		}
		return
	}

	if ($items.Count -ge 2) {
		$byVersion = if ($Latest) {{$_.InstallationVersion}} else {{$_.InstallationVersion.Major}}
		$byProduct = {
			switch ($_.Product.Id) {
				Microsoft.VisualStudio.Product.Enterprise {4}
				Microsoft.VisualStudio.Product.Professional {3}
				Microsoft.VisualStudio.Product.Community {2}
				Microsoft.VisualStudio.Product.BuildTools {1}
				default {0}
			}
		}
		$items = $items | Sort-Object $byVersion, $byProduct
	}

	$item = $items[-1]
	if ($item.InstallationVersion.Major -eq 15) {
		$Version = '15.0'
	}
	else {
		$Version = 'Current'
	}
	Join-Path $item.InstallationPath (Get-MSBuild15Path $Version $Bitness)
}

function Get-MSBuild15Guess {
	[CmdletBinding()] param(
		[string]$Version,
		[string]$Bitness,
		[switch]$Latest,
		[switch]$Prerelease
	)

	if (!($root = ${env:ProgramFiles(x86)})) {$root = $env:ProgramFiles}

	$folders = $(
		if ($Prerelease) {'Preview'}
		elseif ($Version -eq '*') {'2019', '2017'}
		elseif ($Version -eq '16.0') {'2019'}
		else {'2017'}
	)
	foreach($folder in $folders) {
		$items = @(Get-Item -ErrorAction 0 @(
			"$root\Microsoft Visual Studio\$folder\*\$(Get-MSBuild15Path Current $Bitness)"
			"$root\Microsoft Visual Studio\$folder\*\$(Get-MSBuild15Path $Version $Bitness)"
		))
		if ($items) {
			break
		}
	}
	if (!$items) {
		if (!$Prerelease) {
			Get-MSBuild15Guess $Version $Bitness -Latest:$Latest -Prerelease
		}
		return
	}

	if ($items.Count -ge 2) {
		$byVersion = if ($Latest) {{[Version]$_.VersionInfo.FileVersion}} else {{([Version]$_.VersionInfo.FileVersion).Major}}
		$byProduct = {
			switch -Wildcard ($_.FullName) {
				*\Enterprise\* {4}
				*\Professional\* {3}
				*\Community\* {2}
				*\BuildTools\* {1}
				default {0}
			}
		}
		$items = $items | Sort-Object $byVersion, $byProduct
	}

	$items[-1].FullName
}

function Get-MSBuild15 {
	[CmdletBinding()] param(
		[string]$Version,
		[string]$Bitness,
		[switch]$Latest
	)

	if ($path = Get-MSBuild15VSSetup $Version $Bitness -Latest:$Latest) {
		$path
	}
	else {
		Get-MSBuild15Guess $Version $Bitness -Latest:$Latest
	}
}

function Get-MSBuildOldVersion {
	[CmdletBinding()] param(
		[string]$Version,
		[string]$Bitness
	)

	if ([System.IntPtr]::Size -eq 8 -and $Bitness -eq 'x86') {
		$key = "HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\MSBuild\ToolsVersions\$Version"
	}
	else {
		$key = "HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\MSBuild\ToolsVersions\$Version"
	}
	$rp = [Microsoft.Win32.Registry]::GetValue($key, 'MSBuildToolsPath', '')
	if ($rp) {
		Join-Path $rp MSBuild.exe
	}
}

function Get-MSBuildOldLatest {
	[CmdletBinding()] param(
		[string]$Bitness
	)

	$rp = @(Get-ChildItem HKLM:\SOFTWARE\Microsoft\MSBuild\ToolsVersions | Sort-Object {[Version]$_.PSChildName})
	if ($rp) {
		Get-MSBuildOldVersion $rp[-1].PSChildName $Bitness
	}
}

function Get-MSBuildAny {
	[CmdletBinding()] param(
		[string]$Bitness,
		[switch]$Latest
	)

	if ($path = Get-MSBuild15 * $Bitness -Latest:$Latest) {
		$path
	}
	else {
		Get-MSBuildOldLatest $Bitness
	}
}

$ErrorActionPreference = 1
try {
	if ($Version -match '^(.*?)x86\s*$') {
		$Version = $matches[1]
		$Bitness = 'x86'
	}
	else {
		$Bitness = ''
	}
	$Version = $Version.Trim()

	$v16 = [Version]'16.0'
	$v15 = [Version]'15.0'
	$vMax = [Version]'9999.0'
	if (!$Version) {$Version = '*'}
	$vRequired = if ($Version -eq '*') {$vMax} else {[Version]$Version}

	$path = ''
	if ($vRequired -eq $v16 -or $vRequired -eq $v15) {
		$path = Get-MSBuild15 $Version $Bitness -Latest:$Latest
	}
	elseif ($vRequired -lt $v15) {
		$path = Get-MSBuildOldVersion $Version $Bitness
	}
	elseif ($vRequired -eq $vMax) {
		$path = Get-MSBuildAny $Bitness -Latest:$Latest
	}

	if (!$path) {
		throw 'The specified version is not found.'
	}

	if ($MinimumVersion) {
		$vResolved = [Version](& $path -version -nologo)
		if ($vResolved -lt $MinimumVersion) {
			throw "MSBuild resolved version $vResolved is less than required minimum $MinimumVersion."
		}
	}

	$path
}
catch {
	Write-Error "Cannot resolve MSBuild $Version : $_"
}