Subzero: Run cross tests as a much more configurable python script.

crosstest/lit.cfg

+import re
+import lit.formats
+
+# Find FindBaseNaCl in utils.py in ../pydir/ .
+sys.path.insert(0, os.path.dirname(os.path.dirname(__file__)) + '/pydir')
+from utils import FindBaseNaCl
+
+config.name = 'subzero_crosstests'
+config.test_format = lit.formats.ShTest()
+config.suffixes = ['.xtest']
+config.test_source_root = os.path.dirname(__file__)
+config.test_exec_root = config.test_source_root
+
+llvmbintools = [r"\bFileCheck\b"]
+llvmbinpath = ('{root}/toolchain_build/out/llvm_x86_64_linux_work/' +
+               'Release+Asserts/bin').format(root=FindBaseNaCl())

[Mircea Trofin, 2015/03/08 16:23:30]

The path (llvm_x86_64_linux_work/Release+Asserts) means we can't run this on
windows or osx, nor on debug builds. Is this intentional?

[Jim Stichnoth, 2015/03/09 18:16:16]

Good point.  Changing this to be like the other lit test run, where this path is
passed in from Makefile.standalone where it can be overridden via an environment
variable.

Even that's not ideal and will need some work once we add new targets, but it's
tolerated because Makefile.standalone and lit tests are only developer tools,
not used by the bots.

+
+for tool in llvmbintools:
+  # The re.sub() line is adapted from one of LLVM's lit.cfg files.
+  # Extract the tool name from the pattern.  This relies on the tool
+  # name being surrounded by \b word match operators.  If the
+  # pattern starts with "| ", include it in the string to be
+  # substituted.
+  substitution = re.sub(r"^(\\)?((\| )?)\W+b([0-9A-Za-z-_]+)\\b\W*$",
+                        r"\2" + llvmbinpath + "/" + r"\4",
+                        tool)
+  config.substitutions.append((tool, substitution))