Use CMAKE_OBJDUMP when importing profiles in test-suite (#37)

When collecting profiles with `lnt runtest test-suite --use-perf=profile`, it needs a path to objdump to extract the symbols and disassembly. Normally it will try to use `CMAKE_OBJDUMP` from the environment, but AFIAK `lnt` is normally invoked from the command line so no CMake variables are set, so it falls back to just plain old `objdump`.

When running LNT in a cross compilation scenario this leads to a different `objdump` than what CMake uses, which may not support the target (or just straight up not exist). So the profile imports will silently fail to include any code from the binary. 

This fixes it by plumbing through the `CMAKE_OBJDUMP` from the actual llvm-test-suite build. I've left behind the old `os.getenv` as a fallback since `Profile.fromFile` is called from a bunch of other places including `lnt runtest profile`. 

With this patch, using LNT to cross-compile and profile the tests on a remote machine should hopefully "just work"

Author: lukel97

lnt/testing/profile/profile.py

@@ -21,18 +21,20 @@ def __init__(self, impl):
         self.impl = impl
 
     @staticmethod
-    def fromFile(f):
+    def fromFile(f, objdump=None):
         """
         Load a profile from a file.
         """
+        if objdump is None:
+            objdump = os.getenv("CMAKE_OBJDUMP", "objdump")
         for impl in lnt.testing.profile.IMPLEMENTATIONS.values():
             if impl.checkFile(f):
                 ret = None
                 with open(f, 'rb') as fd:
                     if impl is lnt.testing.profile.perf.LinuxPerfProfile:
                         ret = impl.deserialize(
                             fd,
-                            objdump=os.getenv('CMAKE_OBJDUMP', 'objdump'),
+                            objdump,
                             binaryCacheRoot=os.getenv('LNT_BINARY_CACHE_ROOT', ''))
                     else:
                         ret = impl.deserialize(fd)

lnt/tests/test_suite.py

@@ -15,6 +15,7 @@
 
 import datetime
 from collections import defaultdict
+from functools import partial
 import jinja2
 import click
 
@@ -94,7 +95,7 @@
 """
 
 
-def _importProfile(name_filename):
+def _importProfile(objdump, name_filename):
     """_importProfile imports a single profile. It must be at the top level
     (and not within TestSuiteTest) so that multiprocessing can import it
     correctly."""
@@ -104,7 +105,7 @@ def _importProfile(name_filename):
         logger.warning('Profile %s does not exist' % filename)
         return None
 
-    pf = lnt.testing.profile.profile.Profile.fromFile(filename)
+    pf = lnt.testing.profile.profile.Profile.fromFile(filename, objdump)
     if not pf:
         return None
 
@@ -692,7 +693,8 @@ def _extract_cmake_vars_from_cache(self):
                 "CMAKE_C_FLAGS_RELEASE",
                 "CMAKE_C_FLAGS_RELWITHDEBINFO",
                 "CMAKE_C_COMPILER_TARGET",
-                "CMAKE_CXX_COMPILER_TARGET")]
+                "CMAKE_CXX_COMPILER_TARGET",
+                "CMAKE_OBJDUMP")]
         cmake_vars = {}
         for line in cmake_lah_output.split("\n"):
             for pattern, varname in pattern2var:
@@ -828,7 +830,8 @@ def _parse_lit_output(self, path, data, cmake_vars, only_test=False):
             TIMEOUT = 800
             try:
                 pool = multiprocessing.Pool()
-                waiter = pool.map_async(_importProfile, profiles_to_import)
+                func = partial(_importProfile, cmake_vars["CMAKE_OBJDUMP"])
+                waiter = pool.map_async(func, profiles_to_import)
                 samples = waiter.get(TIMEOUT)
                 test_samples.extend([sample
                                      for sample in samples