[Lldb-commits] [lldb] dd67581 - [lldb/test] Enable faulthandler in dotest

[Jordan Rupprecht via lldb-commits]

Author: Jordan Rupprecht
Date: 2020-09-16T14:26:40-07:00
New Revision: dd67581407c1693e43ac8a90b3a20c597614bda8

URL: https://github.com/llvm/llvm-project/commit/dd67581407c1693e43ac8a90b3a20c597614bda8
DIFF: https://github.com/llvm/llvm-project/commit/dd67581407c1693e43ac8a90b3a20c597614bda8.diff

LOG: [lldb/test] Enable faulthandler in dotest

Register the `faulthandler` module so we can see what lldb tests are doing when they misbehave (e.g. run under a test runner that sets a timeout). This will print a stack trace for the following signals:

- `SIGSEGV`, `SIGFPE`, `SIGABRT`, `SIGBUS`, and `SIGILL` (via `faulthandler.enable()`)
- `SIGTERM` (via `faulthandler.register(SIGTERM)`) [This is what our test runners sends when it times out].

The only signal we currently handle is `SIGINT` (via `unittest2.signals.installHandler()`) so there should be no overlap added by this patch.

Because this import is not available until python3, and the `register()` method is not available on Windows, this is enabled defensively.

This should have absolutely no effect when tests are passing (or even normally failing), but can be observed by running this while ninja is running:

```
kill -s SIGTERM $(ps aux | grep dotest.py | head -1 | awk '{print $2}')
```

Reviewed By: JDevlieghere

Differential Revision: https://reviews.llvm.org/D87637

Added: 
    

Modified: 
    lldb/packages/Python/lldbsuite/test/dotest.py

Removed: 
    


################################################################################
diff  --git a/lldb/packages/Python/lldbsuite/test/dotest.py b/lldb/packages/Python/lldbsuite/test/dotest.py
index 30d6afc231fd..b4eddda91403 100644
--- a/lldb/packages/Python/lldbsuite/test/dotest.py
+++ b/lldb/packages/Python/lldbsuite/test/dotest.py
@@ -449,6 +449,18 @@ def parseOptionsAndInitTestdirs():
 
     lldbtest_config.codesign_identity = args.codesign_identity
 
+def registerFaulthandler():
+    try:
+        import faulthandler
+    except ImportError:
+        # faulthandler is not available until python3
+        return
+
+    faulthandler.enable()
+    # faulthandler.register is not available on Windows.
+    if getattr(faulthandler, 'register', None):
+        faulthandler.register(signal.SIGTERM, chain=True)
+
 def setupSysPath():
     """
     Add LLDB.framework/Resources/Python to the search paths for modules.
@@ -875,6 +887,9 @@ def run_suite():
     #
     parseOptionsAndInitTestdirs()
 
+    # Print a stack trace if the test hangs or is passed SIGTERM.
+    registerFaulthandler()
+
     setupSysPath()
 
     import lldbconfig