go.cmd used cmd.exe to invoke PowerShell, which mangled arguments:
cmd.exe treats ^ as an escape character (so -run "^$" became -run "$",
running all tests instead of none) and = signs also caused issues in
the PowerShell→cmd.exe argument passing layer.
Replace it with a tiny no_std Rust binary (19KB, 32-bit x86 for
universal Windows compat: x86/x64/ARM64) that directly invokes the
Tailscale Go toolchain via CreateProcessW. The raw command line from
GetCommandLineW is passed through to CreateProcessW with only argv[0]
replaced, so arguments are never parsed or re-escaped.
The binary also handles first-run toolchain download natively using
curl.exe and tar.exe (both ship with Windows 10+), so PowerShell is
no longer required for normal operation. The PowerShell fallback is
only used for the rare TS_USE_GOCROSS=1 path.
PowerShell prefers go.exe over go.cmd when resolving ./tool/go, so
this is a drop-in replacement.
With go.exe in place, the CI can use the natural -bench=. -benchtime=1x
-run="^$" flags directly.
Also removes tool/go-win.ps1 which is now unused.
Updates #19255
Change-Id: I80da23285b74796e7694b89cff29a9fa0eaa6281
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Nathan Perry
Brad Fitzpatrick