Compare object files from two revisions (MSVC)

compare.ps1

param(
    [Parameter(Mandatory=$True)] [String] $SourceDir,
    [Parameter(Mandatory=$True)] [String] $OldRevision,
    [Parameter(Mandatory=$True)] [String] $NewRevision
)

$SourceDir = (Get-Item $SourceDir).FullName
$BuildDir = (Get-Item .).FullName

$BuildConfig = 'RelWithDebInfo'

function DoBuild($Revision, $ObjectFilesDir) {
    Set-Location $BuildDir
    cmake --build . --config $BuildConfig --target clean

    Set-Location $SourceDir
    git checkout .
    git checkout $Revision
    git apply "$PSScriptRoot\line_to_zero.patch"  # change `__LINE__` to `0` to avoid extra changes

    Set-Location $BuildDir
    cmake --build . --config $BuildConfig

    Remove-Item $ObjectFilesDir -Recurse -Force > $null

    Get-ChildItem . -Recurse -Exclude *CompilerId* -Include *.obj -File | ForEach-Object {
        $ObjectFile = Resolve-Path $_.FullName -Relative
        $ObjectFileDir = Resolve-Path (Get-Item "$ObjectFile\..").FullName -Relative
        New-Item "$ObjectFilesDir\$ObjectFileDir" -ItemType Directory -Force > $null
        Copy-Item $ObjectFile "$ObjectFilesDir\$ObjectFile" -Force > $null
    }
}

function GetFileList($Dir) {
    Set-Location $Dir && Get-ChildItem . -Recurse | ForEach-Object { Resolve-Path $_.FullName -Relative }
}

$OldObjectFilesDir = "${BuildDir}.OldObjectFiles"
DoBuild $OldRevision $OldObjectFilesDir

$NewObjectFilesDir = "${BuildDir}.NewObjectFiles"
DoBuild $NewRevision $NewObjectFilesDir

Compare-Object (GetFileList $OldObjectFilesDir) (GetFileList $NewObjectFilesDir)

Set-Location $OldObjectFilesDir
Get-ChildItem . -Recurse -Include *.obj -File | ForEach-Object -Parallel {
    function DumpObject($ObjectFilePath) {
        llvm-objdump --disassemble $ObjectFilePath | `
            Select-Object -Skip 4 | `
            Out-File "$ObjectFilePath.asm"
        return "$ObjectFilePath.asm"
    }

    $ObjectFile = Resolve-Path $_.FullName -Relative
    $OldObjectFileDump = DumpObject "$using:OldObjectFilesDir\$ObjectFile"
    $NewObjectFileDump = DumpObject "$using:NewObjectFilesDir\$ObjectFile"
    git diff --no-index $OldObjectFileDump $NewObjectFileDump
}

Set-Location $BuildDir