Allow conditional lit tests in Subzero, based on build flags.

tests_lit/lit.cfg

 # Taken from utils/lit/tests in the LLVM tree and hacked together to support
 # our tests.
+#
+# Note: For X2i and ifX commands, the following values are allowed for X
+# (i.e. compiler setup):
+#
+#   m : Run when llvm2ice corresponds to minimal Subzero
+#   p : Run when llvm2ice corresponds to Subzero building ICE from PNaCl
+#       bitcode directly.
+#   l : Run when llvm2ice corresponds to Subzero building ICE by reading
+#       PNaCL bitcode into LLVM IR, and converting to ICE.
+#   lc : Runwhen llvm2ice corresponds to Subzero parsing LLVM source into
+#        LLVM IR, and converting to ICE.
 
 # -*- Python -*-
 
 import os
 import re
 import sys
 
 import lit.formats
 
 sys.path.insert(0, 'pydir')
 from utils import FindBaseNaCl
+from buildatts import getBuildAttributes
 
 # name: The name of this test suite.
 config.name = 'subzero'
 
 # testFormat: The test format to use to interpret tests.
 config.test_format = lit.formats.ShTest()
 
 # suffixes: A list of file extensions to treat as test files.
 config.suffixes = ['.ll']
 
 # test_source_root: The root path where tests are located.
 config.test_source_root = os.path.dirname(__file__)
 config.test_exec_root = config.test_source_root
 config.target_triple = '(unused)'
 
 src_root = os.path.join(FindBaseNaCl(), 'toolchain_build/src/subzero')
 bin_root = src_root
 config.substitutions.append(('%{src_root}', src_root))
 config.substitutions.append(('%{python}', sys.executable))
 
 pydir = os.path.join(bin_root, 'pydir')
 
 # Finding LLVM binary tools. All tools used in the tests must be listed in
 # the llvmbintools list.
 llvmbinpath = os.path.abspath(os.environ.get('LLVM_BIN_PATH'))
 
-# Finding Subzero tools
+# Define the location of the llvm2ice tool.
 llvm2icetool = os.path.join(bin_root, 'llvm2ice')
 
-# Convert LLVM source to PNaCl bitcode, read using the
-# Subzero bitcode reader, and then translate.
-config.substitutions.append(
-  ('%p2i', ' '.join([os.path.join(pydir, 'run-llvm2ice.py'),
-                     '--llvm2ice', llvm2icetool,
-                     '--llvm-bin-path', llvmbinpath
-                    ])))
+# Add build attributes of llvm2ice tool to the set of available features.
+config.available_features.update(getBuildAttributes(llvm2icetool))
 
-# Convert LLVM source to PNaCl bitcode, read using the PNaCl bitcode reader,
-# convert to ICE using the ICE Converter, and then translate.
-# TODO(kschimpf) Deprecated, remove once p2i working.
-config.substitutions.append(
-  ('%l2i', ' '.join([os.path.join(pydir, 'run-llvm2ice.py'),
-                     '--llvm', '--llvm2ice', llvm2icetool,
-                     '--llvm-bin-path', llvmbinpath
-                    ])))
+# Base command for testing build attributes
+if_atts_cmd = [os.path.join(pydir, 'buildatts.py'), '--llvm2ice', llvm2icetool]
+ifm_atts_cmd = if_atts_cmd + ['--att=minimal', '--att=p2i']
+ifp_atts_cmd = if_atts_cmd + ['--att=p2i']
+ifl_atts_cmd = if_atts_cmd + ['--att=l2i']
+iflc_atts_cmd = if_atts_cmd + ['--att=lc2i']
 
-# Read LLVM source, convert to ICE using the ICE converter, and then translate.
-# Note: l2i is preferred over lc2i, since it uses PNaCl bitcode.
-# TODO(kschimpf) Deprecated, remove once p2i working.
-config.substitutions.append(
-  ('%lc2i', ' '.join([os.path.join(pydir, 'run-llvm2ice.py'),
-                      '--llvm-source', '--llvm2ice', llvm2icetool,
-                      '--llvm-bin-path', llvmbinpath
-                    ])))
+# Base command for running llvm2ice
+llvm2ice_cmd = [os.path.join(pydir, 'run-llvm2ice.py'),
+                '--llvm2ice', llvm2icetool,
+                '--llvm-bin-path', llvmbinpath]
+
+# Run commands only if corresponding build attributes apply, including
+# for each compiler setup.
+config.substitutions.append(('%ifm', ' '.join(ifm_atts_cmd)))
+config.substitutions.append(('%ifp', ' '.join(ifp_atts_cmd)))
+config.substitutions.append(('%iflc', ' '.join(iflc_atts_cmd)))
+config.substitutions.append(('%ifl', ' '.join(ifl_atts_cmd)))
+config.substitutions.append(('%if', ' '.join(if_atts_cmd)))
+
+# Translate LLVM source for each compiler setup.
+config.substitutions.append(('%m2i', ' '.join(ifm_atts_cmd + llvm2ice_cmd)))
+config.substitutions.append(('%p2i', ' '.join(ifp_atts_cmd + llvm2ice_cmd)))
+config.substitutions.append(('%l2i', ' '.join(ifl_atts_cmd + llvm2ice_cmd
+                                              + ['--llvm'])))
+config.substitutions.append(('%lc2i', ' '.join(iflc_atts_cmd + llvm2ice_cmd
+                                               + ['--llvm-source'])))
 
 config.substitutions.append(('%llvm2ice', llvm2icetool))
 config.substitutions.append(('%szdiff', os.path.join(pydir, 'szdiff.py')))
 
 llvmbintools = [r"\bFileCheck\b", r"\bllvm-as\b", r"\bllvm-mc\b",
                 r"\bllvm-objdump\b", r"\bnot\b", r"\bpnacl-freeze\b",
                 r"\bpnacl-bcdis\b"]
 
 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))
 
 # Add a feature to detect the Python version.
 config.available_features.add("python%d.%d" % (sys.version_info[0],
                                                sys.version_info[1]))
 
 # Debugging output
 def dbg(s):
   print '[DBG] %s' % s
 
 dbg('bin_root = %s' % bin_root)
 dbg('llvmbinpath = %s' % llvmbinpath)