nvcc - added post-processing of stderr from nvcc to remove warnings about things

we do on purpose. Also moved printing of the remainder of the message to INFO level logging, which might be a bad idea. But nvcc spews things that are not errors to stderr which are not easy to filter out. I'm thinking of the warnings that _POSIX_SOURCE is redefined, followed by a multiline header traceback. We do not want to print that to stderr by default every time someone compiles anything with nvcc. If compilation fails, then the whole nvcc stderr goes to our stderr anyway.

nvcc - added post-processing of stderr from nvcc to remove warnings about things
42a7c2ea · James Bergstra · bb892b77 · 42a7c2ea
--- a/theano/sandbox/cuda/nvcc_compiler.py
+++ b/theano/sandbox/cuda/nvcc_compiler.py
@@ -127,8 +127,23 @@ def nvcc_module_compile_str(module_name, src_code, location=None, include_dirs=[
    # the number of registers required to inform the maximum number of threads per block.
    debug('Running cmd', ' '.join(cmd))
-    p = subprocess.Popen(cmd, stderr=subprocess.PIPE)
+    p = subprocess.Popen(cmd, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
-    stderr = p.communicate()[1] 
+    nvcc_stdout, nvcc_stderr = p.communicate()[:2]
+    if nvcc_stdout:
+        # this doesn't happen to my knowledge
+        print >> sys.stderr, "DEBUG: nvcc STDOUT", nvcc_stdout
+    for eline in nvcc_stderr.split('\n'):
+        if not eline:
+            continue
+        if 'skipping incompatible' in eline: #ld is skipping an incompatible library
+            continue
+        if 'declared but never referenced' in eline:
+            continue
+        if 'statement is unreachable' in eline:
+            continue
+        _logger.info("NVCC: "+eline)
    if p.returncode: 
        # filter the output from the compiler