build: add Waf option to run without building
Workaround for issue #14 (closed).
This will also facilitate running a program in parallel across multiple cores, because multiple processes invoking waf build at the same time (in the same directory) can cause concurrency issues such as:
File "waf-tools/clang_compilation_database.py", line 47, in write_compilation_database
root = json.load(database_file)
File "/usr/lib/python2.7/json/__init__.py", line 290, in load
**kw)
File "/usr/lib/python2.7/json/__init__.py", line 338, in loads
return _default_decoder.decode(s)
File "/usr/lib/python2.7/json/decoder.py", line 366, in decode
obj, end = self.raw_decode(s, idx=_w(s, 0).end())
File "/usr/lib/python2.7/json/decoder.py", line 384, in raw_decode
raise ValueError("No JSON object could be decoded")
ValueError: No JSON object could be decoded
Edited by Tom Henderson