Windows: kill the whole process-tree when terminating a process

Author: cmaglie

go.mod

@@ -1,8 +1,13 @@
 module github.com/arduino/go-paths-helper
 
-go 1.21
+go 1.23.0
 
-require github.com/stretchr/testify v1.8.4
+toolchain go1.23.2
+
+require (
+	github.com/stretchr/testify v1.8.4
+	golang.org/x/sys v0.32.0
+)
 
 require (
 	github.com/davecgh/go-spew v1.1.1 // indirect

go.sum

@@ -4,6 +4,8 @@ github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZb
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/stretchr/testify v1.8.4 h1:CcVxjf3Q8PM0mHUKJCdn+eZZtm5yQwehR5yeSVQQcUk=
 github.com/stretchr/testify v1.8.4/go.mod h1:sz/lmYIOXD/1dqDmKjjqLyZ2RngseejIcXlSw2iwfAo=
+golang.org/x/sys v0.32.0 h1:s77OFDvIQeibCmezSnk/q6iAfkdiQaJi4VzroCFrN20=
+golang.org/x/sys v0.32.0/go.mod h1:BJP2sWEmIv4KK5OTEluFJCKSidICx8ciO85XgH3Ak8k=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=

process_windows.go

@@ -30,8 +30,12 @@
 package paths
 
 import (
+	"fmt"
 	"os/exec"
 	"syscall"
+	"unsafe"
+
+	"golang.org/x/sys/windows"
 )
 
 func tellCommandNotToSpawnShell(oscmd *exec.Cmd) {
@@ -46,5 +50,41 @@ func tellCommandToStartOnNewProcessGroup(_ *exec.Cmd) {
 }
 
 func kill(oscmd *exec.Cmd) error {
-	return oscmd.Process.Kill()
+	return killProcessTree(uint32(oscmd.Process.Pid))
+}
+
+func killProcessTree(pid uint32) error {
+	// Inspired by: https://stackoverflow.com/a/36089871/1655275
+
+	// Make a snapshot of the current running processes
+	snapshot, err := windows.CreateToolhelp32Snapshot(windows.TH32CS_SNAPPROCESS, 0)
+	if err != nil {
+		return fmt.Errorf("getting running processes snapshot: %w", err)
+	}
+
+	// Iterate and filter child processes of the current process
+	var processEntry windows.ProcessEntry32
+	processEntry.Size = uint32(unsafe.Sizeof(processEntry))
+	if windows.Process32First(snapshot, &processEntry) == nil {
+		for {
+			if processEntry.ParentProcessID == pid {
+				// Recurse on the childrens
+				if err := killProcessTree(processEntry.ProcessID); err != nil {
+					return fmt.Errorf("error killing child process: %w", err)
+				}
+			}
+
+			if windows.Process32Next(snapshot, &processEntry) != nil {
+				break
+			}
+		}
+	}
+
+	// And finally, kill the parent
+	process, err := windows.OpenProcess(windows.PROCESS_ALL_ACCESS, false, pid)
+	if err != nil {
+		return fmt.Errorf("opening process for kill: %w", err)
+	}
+	defer windows.CloseHandle(process)
+	return windows.TerminateProcess(process, 128)
 }