[WS] Inform about unexisting compilers and qemu

git-svn-id: svn://kolibrios.org@9411 a494cfbc-eb01-0410-851d-a64ba20cac60

_tools/lib/logging.py

@@ -1,4 +1,21 @@
+import shutil
+
 def log(s, end = "\n"):
     print(s, end = end, flush = True)
 
+def require_tools(names):
+    assert(type(names) == list or type(names) == tuple)
+    for name in names:
+        assert(type(name) == str)
+
+    not_found = []
+    for name in names:
+        if shutil.which(name) is None:
+            not_found.append(name)
+
+    if len(not_found) != 0:
+        log("Sorry, I can't find some tools:")
+        for name in not_found:
+            print(f"- {name}")
+        exit(1)