Adds stacktrace support from Abseil to Google Test

This change adds the ability to generate stacktraces in Google Test on
both failures of assertions/expectations and on crashes. The
stacktrace support is conditionally available only when using Abseil
with Google Test.

To use this support, run the test under Bazel with a command like this:

bazel test --define absl=1 --test_env=GTEST_INSTALL_FAILURE_SIGNAL_HANDLER=1 //path/to/your:test

The "--define absl=1" part enables stacktraces on assertion/expectation
failures.

The "--test_env=GTEST_INSTALL_FAILURE_SIGNAL_HANDLER=1" part enables
the signal handler that logs a stacktrace in the event of a crash
(this also requires the "--define absl=1" part). This is not the
default since it may interfere with existing tests.

1 files changed, 6 insertions, 1 deletions

diff --git a/googletest/test/gtest_xml_output_unittest.py b/googletest/test/gtest_xml_output_unittest.py
index 6ffb6e3..faedd4e 100755
--- a/googletest/test/gtest_xml_output_unittest.py
+++ b/googletest/test/gtest_xml_output_unittest.py
@@ -47,17 +47,22 @@ GTEST_OUTPUT_FLAG = '--gtest_output'
 GTEST_DEFAULT_OUTPUT_FILE = 'test_detail.xml'
 GTEST_PROGRAM_NAME = 'gtest_xml_output_unittest_'
 
+# The flag indicating stacktraces are not supported
+NO_STACKTRACE_SUPPORT_FLAG = '--no_stacktrace_support'
+
 # The environment variables for test sharding.
 TOTAL_SHARDS_ENV_VAR = 'GTEST_TOTAL_SHARDS'
 SHARD_INDEX_ENV_VAR = 'GTEST_SHARD_INDEX'
 SHARD_STATUS_FILE_ENV_VAR = 'GTEST_SHARD_STATUS_FILE'
 
-SUPPORTS_STACK_TRACES = False
+SUPPORTS_STACK_TRACES = NO_STACKTRACE_SUPPORT_FLAG not in sys.argv
 
 if SUPPORTS_STACK_TRACES:
   STACK_TRACE_TEMPLATE = '\nStack trace:\n*'
 else:
   STACK_TRACE_TEMPLATE = ''
+  # unittest.main() can't handle unknown flags
+  sys.argv.remove(NO_STACKTRACE_SUPPORT_FLAG)
 
 EXPECTED_NON_EMPTY_XML = """<?xml version="1.0" encoding="UTF-8"?>
 <testsuites tests="23" failures="4" disabled="2" errors="0" time="*" timestamp="*" name="AllTests" ad_hoc_property="42">