[AIX][lit] Don't depend on psutil on AIX

Summary:
On AIX psutil can run into problems with permissions to read the process
tree, which causes problems for python timeout tests which need to kill off
a test and it's children.

This patch adds a workaround by invoking shell via subprocess and using a
platform specific option to ps to list all the descendant processes so we can
kill them. We add some checks so lit can tell whether timeout tests are
supported with out exposing whether we are utilizing the psutil
implementation or the alternative.

Reviewers: hubert.reinterpretcast, andusy, davide, delcypher

Reviewed By: delcypher

Subscribers: davide, delcypher, christof, lldb-commits, libcxx-commits, llvm-commits

Tags: #lldb, #libc, #llvm

Differential Revision: https://reviews.llvm.org/D64251

llvm-svn: 366912

7 files changed, 98 insertions, 59 deletions

diff --git a/libcxx/utils/libcxx/util.py b/libcxx/utils/libcxx/util.py
index 46c09bf6669..2fd95232abb 100644
--- a/libcxx/utils/libcxx/util.py
+++ b/libcxx/utils/libcxx/util.py
@@ -253,24 +253,27 @@ def killProcessAndChildren(pid):
     TODO: Reimplement this without using psutil so we can
           remove our dependency on it.
     """
-    import psutil
-    try:
-        psutilProc = psutil.Process(pid)
-        # Handle the different psutil API versions
+    if platform.system() == 'AIX':
+        subprocess.call('kill -kill $(ps -o pid= -L{})'.format(pid), shell=True)
+    else:
+        import psutil
         try:
-            # psutil >= 2.x
-            children_iterator = psutilProc.children(recursive=True)
-        except AttributeError:
-            # psutil 1.x
-            children_iterator = psutilProc.get_children(recursive=True)
-        for child in children_iterator:
+            psutilProc = psutil.Process(pid)
+            # Handle the different psutil API versions
             try:
-                child.kill()
-            except psutil.NoSuchProcess:
-                pass
-        psutilProc.kill()
-    except psutil.NoSuchProcess:
-        pass
+                # psutil >= 2.x
+                children_iterator = psutilProc.children(recursive=True)
+            except AttributeError:
+                # psutil 1.x
+                children_iterator = psutilProc.get_children(recursive=True)
+            for child in children_iterator:
+                try:
+                    child.kill()
+                except psutil.NoSuchProcess:
+                    pass
+            psutilProc.kill()
+        except psutil.NoSuchProcess:
+            pass
 
 
 def executeCommandVerbose(cmd, *args, **kwargs):
diff --git a/lldb/lit/lit.cfg.py b/lldb/lit/lit.cfg.py
index ad659eaf87f..b56e41e720b 100644
--- a/lldb/lit/lit.cfg.py
+++ b/lldb/lit/lit.cfg.py
@@ -1,6 +1,7 @@
 # -*- Python -*-
 
 import os
+import platform
 import re
 import shutil
 import site
@@ -75,13 +76,14 @@ for i in ['module-cache-clang', 'module-cache-lldb']:
         shutil.rmtree(cachedir)
 
 # Set a default per-test timeout of 10 minutes. Setting a timeout per test
-# requires the psutil module and lit complains if the value is set but the
-# module can't be found.
-try:
-    import psutil  # noqa: F401
+# requires that killProcessAndChildren() is supported on the platform and
+# lit complains if the value is set but it is not supported.
+supported, errormsg = lit_config.maxIndividualTestTimeIsSupported
+if supported:
     lit_config.maxIndividualTestTime = 600
-except ImportError:
-    pass
+else:
+    lit_config.warning("Could not set a default per-test timeout. " + errormsg)
+
 
 # If running tests natively, check for CPU features needed for some tests.
 
diff --git a/llvm/utils/lit/lit/LitConfig.py b/llvm/utils/lit/lit/LitConfig.py
index 31eeb76288b..35ff0590bd6 100644
--- a/llvm/utils/lit/lit/LitConfig.py
+++ b/llvm/utils/lit/lit/LitConfig.py
@@ -1,6 +1,7 @@
 from __future__ import absolute_import
 import inspect
 import os
+import platform
 import sys
 
 import lit.Test
@@ -76,6 +77,19 @@ class LitConfig(object):
         """
         return self._maxIndividualTestTime
 
+    @property
+    def maxIndividualTestTimeIsSupported(self):
+        """
+            Returns a tuple (<supported> , <error message>)
+            where
+            `<supported>` is True if setting maxIndividualTestTime is supported
+                on the current host, returns False otherwise.
+            `<error message>` is an empty string if `<supported>` is True,
+                otherwise is contains a string describing why setting
+                maxIndividualTestTime is not supported.
+        """
+        return lit.util.killProcessAndChildrenIsSupported()
+
     @maxIndividualTestTime.setter
     def maxIndividualTestTime(self, value):
         """
@@ -86,16 +100,13 @@ class LitConfig(object):
             self.fatal('maxIndividualTestTime must set to a value of type int.')
         self._maxIndividualTestTime = value
         if self.maxIndividualTestTime > 0:
-            # The current implementation needs psutil to set
+            # The current implementation needs psutil on some platforms to set
             # a timeout per test. Check it's available.
             # See lit.util.killProcessAndChildren()
-            try:
-                import psutil  # noqa: F401
-            except ImportError:
-                self.fatal("Setting a timeout per test requires the"
-                           " Python psutil module but it could not be"
-                           " found. Try installing it via pip or via"
-                           " your operating system's package manager.")
+            supported, errormsg = self.maxIndividualTestTimeIsSupported
+            if not supported:
+                self.fatal('Setting a timeout per test not supported. ' +
+                           errormsg)
         elif self.maxIndividualTestTime < 0:
             self.fatal('The timeout per test must be >= 0 seconds')
 
diff --git a/llvm/utils/lit/lit/util.py b/llvm/utils/lit/lit/util.py
index 2a61ef7736a..7eb5eaaa2ff 100644
--- a/llvm/utils/lit/lit/util.py
+++ b/llvm/utils/lit/lit/util.py
@@ -423,34 +423,56 @@ def findPlatformSdkVersionOnMacOS(config, lit_config):
             return out.decode()
     return None
 
+def killProcessAndChildrenIsSupported():
+    """
+        Returns a tuple (<supported> , <error message>)
+        where
+        `<supported>` is True if `killProcessAndChildren()` is supported on
+            the current host, returns False otherwise.
+        `<error message>` is an empty string if `<supported>` is True,
+            otherwise is contains a string describing why the function is
+            not supported.
+    """
+    if platform.system() == 'AIX':
+        return (True, "")
+    try:
+        import psutil  # noqa: F401
+        return (True, "")
+    except ImportError:
+        return (False,  "Requires the Python psutil module but it could"
+                        " not be found. Try installing it via pip or via"
+                        " your operating system's package manager.")
 
 def killProcessAndChildren(pid):
     """This function kills a process with ``pid`` and all its running children
-    (recursively). It is currently implemented using the psutil module which
-    provides a simple platform neutral implementation.
+    (recursively). It is currently implemented using the psutil module on some
+    platforms which provides a simple platform neutral implementation.
 
-    TODO: Reimplement this without using psutil so we can       remove
-    our dependency on it.
+    TODO: Reimplement this without using psutil on all platforms so we can
+    remove our dependency on it.
 
     """
-    import psutil
-    try:
-        psutilProc = psutil.Process(pid)
-        # Handle the different psutil API versions
+    if platform.system() == 'AIX':
+        subprocess.call('kill -kill $(ps -o pid= -L{})'.format(pid), shell=True)
+    else:
+        import psutil
         try:
-            # psutil >= 2.x
-            children_iterator = psutilProc.children(recursive=True)
-        except AttributeError:
-            # psutil 1.x
-            children_iterator = psutilProc.get_children(recursive=True)
-        for child in children_iterator:
+            psutilProc = psutil.Process(pid)
+            # Handle the different psutil API versions
             try:
-                child.kill()
-            except psutil.NoSuchProcess:
-                pass
-        psutilProc.kill()
-    except psutil.NoSuchProcess:
-        pass
+                # psutil >= 2.x
+                children_iterator = psutilProc.children(recursive=True)
+            except AttributeError:
+                # psutil 1.x
+                children_iterator = psutilProc.get_children(recursive=True)
+            for child in children_iterator:
+                try:
+                    child.kill()
+                except psutil.NoSuchProcess:
+                    pass
+            psutilProc.kill()
+        except psutil.NoSuchProcess:
+            pass
 
 
 try:
diff --git a/llvm/utils/lit/tests/googletest-timeout.py b/llvm/utils/lit/tests/googletest-timeout.py
index 8b7d10fc1f0..0761ad0796e 100644
--- a/llvm/utils/lit/tests/googletest-timeout.py
+++ b/llvm/utils/lit/tests/googletest-timeout.py
@@ -1,4 +1,4 @@
-# REQUIRES: python-psutil
+# REQUIRES: lit-max-individual-test-time
 
 # Check that the per test timeout is enforced when running GTest tests.
 #
diff --git a/llvm/utils/lit/tests/lit.cfg b/llvm/utils/lit/tests/lit.cfg
index 4648b1bfc9c..ebdcb5000b9 100644
--- a/llvm/utils/lit/tests/lit.cfg
+++ b/llvm/utils/lit/tests/lit.cfg
@@ -1,6 +1,7 @@
 # -*- Python -*-
 
 import os
+import platform
 import sys
 
 import lit.formats
@@ -56,10 +57,10 @@ if lit_config.params.get('check-coverage', None):
         os.path.dirname(__file__), ".coveragerc")
 
 # Add a feature to detect if psutil is available
-try:
-    import psutil
-    lit_config.note('Found python psutil module')
-    config.available_features.add("python-psutil")
-except ImportError:
-    lit_config.warning('Could not import psutil. Some tests will be skipped and'
-                       ' the --timeout command line argument will not work.')
+supported, errormsg = lit_config.maxIndividualTestTimeIsSupported
+if supported:
+    config.available_features.add("lit-max-individual-test-time")
+else:
+    lit_config.warning('Setting a timeout per test not supported. ' + errormsg
+                       + ' Some tests will be skipped and the --timeout'
+                         ' command line argument will not work.')
diff --git a/llvm/utils/lit/tests/shtest-timeout.py b/llvm/utils/lit/tests/shtest-timeout.py
index 1208e7379d0..56415fe5b3c 100644
--- a/llvm/utils/lit/tests/shtest-timeout.py
+++ b/llvm/utils/lit/tests/shtest-timeout.py
@@ -1,4 +1,4 @@
-# REQUIRES: python-psutil
+# REQUIRES: lit-max-individual-test-time
 
 # llvm.org/PR33944
 # UNSUPPORTED: system-windows