builder: use unique .tmp.c and .tmp.c.rsp files, and rm them on successfull non debug builds.

vlib/v/builder/cc.v

@@ -78,6 +78,14 @@ fn (mut v Builder) find_win_cc() ? {
 
 fn (mut v Builder) post_process_c_compiler_output(res os.Result) {
 	if res.exit_code == 0 {
+		for tmpfile in v.pref.cleanup_files {
+			if os.is_file(tmpfile) {
+				if v.pref.is_verbose {
+					eprintln('>> remove tmp file: $tmpfile')
+				}
+				os.rm(tmpfile)
+			}
+		}
 		return
 	}
 	for emsg_marker in [c_verror_message_marker, 'error: include file '] {
@@ -493,6 +501,10 @@ fn (mut v Builder) cc() {
 	os.write_file(response_file, response_file_content) or {
 		verror('Unable to write response file "$response_file"')
 	}
+	if !debug_mode {
+		v.pref.cleanup_files << v.out_name_c
+		v.pref.cleanup_files << response_file
+	}
 	start:
 	todo()
 	// TODO remove

vlib/v/builder/compile.v

@@ -5,6 +5,7 @@ module builder
 
 import time
 import os
+import rand
 import v.pref
 import v.util
 
@@ -23,7 +24,8 @@ fn get_vtmp_folder() string {
 
 fn get_vtmp_filename(base_file_name string, postfix string) string {
 	vtmp := get_vtmp_folder()
-	return os.real_path(os.join_path(vtmp, os.file_name(os.real_path(base_file_name)) + postfix))
+	uniq := rand.u64()
+	return os.real_path(os.join_path(vtmp, os.file_name(os.real_path(base_file_name)) + '.${uniq}${postfix}'))
 }
 
 pub fn compile(command string, pref &pref.Preferences) {

vlib/v/pref/pref.v

@@ -126,6 +126,7 @@ pub mut:
 	show_timings        bool // show how much time each compiler stage took
 	is_ios_simulator    bool
 	is_apk              bool // build as Android .apk format
+	cleanup_files       []string // list of temporary *.tmp.c and *.tmp.c.rsp files. Cleaned up on successfull builds.
 }
 
 pub fn parse_args(args []string) (&Preferences, string) {