"lit not-existing.c" prints "contained no tests" warning

[lattner]

Bugzilla Link	10213
Version	trunk
OS	All
CC	@modocache

Extended Description

I would expect:

$ rm frotz.c
$ lit frotz.c

to produce an error about the file not existing. Instead it prints a very limp warning:

lit.py: lit.cfg:143: note: using clang: '/Volumes/Data/Users/sabre/cvs/llvm-2/Debug+Asserts/bin/clang'
lit.py: main.py:517: warning: input 'frotz.c' contained no tests
-- Testing: 0 tests, 16 threads --
Testing Time: 0.00s

1 warning(s) in tests.

which is easy to miss, and I commonly get when I forget to include the full path to a testcase I'm working with.

[lattner]

assigned to @modocache

[modocache]

The output is slightly different, but the report is still relevant:

lit /does/not/exist.c
lit.py: ~/llvm/utils/lit/lit/discovery.py:113: warning: unable to find test suite for '/does/not/exist.c'
lit.py: ~/llvm/utils/lit/lit/discovery.py:224: warning: input '/does/not/exist.c' contained no tests
-- Testing: 0 tests, 0 threads --
Testing Time: 0.02s

2 warning(s) in tests.

The above command exits successfully. I agree that it should result in an error.