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.

BUILD.bazel

@@ -38,7 +38,7 @@ licenses(["notice"])
 
 config_setting(
     name = "windows",
-    values = { "cpu": "x64_windows" },
+    values = {"cpu": "x64_windows"},
 )
 
 config_setting(
@@ -51,7 +51,6 @@ config_setting(
     values = {"define": "absl=1"},
 )
 
-
 # Google Test including Google Mock
 cc_library(
     name = "gtest",
@@ -70,7 +69,7 @@ cc_library(
             "googlemock/src/gmock_main.cc",
         ],
     ),
-    hdrs =glob([
+    hdrs = glob([
         "googletest/include/gtest/*.h",
         "googlemock/include/gmock/*.h",
     ]),
@@ -81,6 +80,14 @@ cc_library(
             "//conditions:default": ["-pthread"],
         },
     ),
+    defines = select(
+        {
+            ":has_absl": [
+                "GTEST_HAS_ABSL=1",
+            ],
+            "//conditions:default": [],
+        },
+    ),
     includes = [
         "googlemock",
         "googlemock/include",
@@ -94,21 +101,18 @@ cc_library(
             "-pthread",
         ],
     }),
-    defines = select ({
-        ":has_absl": [
-        "GTEST_HAS_ABSL=1",
-        ],
-        "//conditions:default": [],
-    }
-    ),
-    deps = select ({
+    deps = select(
+        {
             ":has_absl": [
+                "@com_google_absl//absl/debugging:failure_signal_handler",
+                "@com_google_absl//absl/debugging:stacktrace",
+                "@com_google_absl//absl/debugging:symbolize",
+                "@com_google_absl//absl/strings",
                 "@com_google_absl//absl/types:optional",
-        "@com_google_absl//absl/strings"
             ],
             "//conditions:default": [],
-    }
-    )
+        },
+    ),
 )
 
 cc_library(

googletest/src/gtest-internal-inl.h

@@ -446,6 +446,16 @@ class OsStackTraceGetter : public OsStackTraceGetterInterface {
   virtual void UponLeavingGTest();
 
  private:
+#if GTEST_HAS_ABSL
+  Mutex mutex_;  // Protects all internal state.
+
+  // We save the stack frame below the frame that calls user code.
+  // We do this because the address of the frame immediately below
+  // the user code changes between the call to UponLeavingGTest()
+  // and any calls to the stack trace code from within the user code.
+  void* caller_frame_ = nullptr;
+#endif  // GTEST_HAS_ABSL
+
   GTEST_DISALLOW_COPY_AND_ASSIGN_(OsStackTraceGetter);
 };
 

googletest/src/gtest.cc

@@ -139,6 +139,13 @@
 # define vsnprintf _vsnprintf
 #endif  // GTEST_OS_WINDOWS
 
+#if GTEST_HAS_ABSL
+#include "absl/debugging/failure_signal_handler.h"
+#include "absl/debugging/stacktrace.h"
+#include "absl/debugging/symbolize.h"
+#include "absl/strings/str_cat.h"
+#endif  // GTEST_HAS_ABSL
+
 namespace testing {
 
 using internal::CountIf;
@@ -228,6 +235,13 @@ GTEST_DEFINE_string_(
     "exclude).  A test is run if it matches one of the positive "
     "patterns and does not match any of the negative patterns.");
 
+GTEST_DEFINE_bool_(
+    install_failure_signal_handler,
+    internal::BoolFromGTestEnv("install_failure_signal_handler", false),
+    "If true and supported on the current platform, " GTEST_NAME_ " should "
+    "install a signal handler that dumps debugging information when fatal "
+    "signals are raised.");
+
 GTEST_DEFINE_bool_(list_tests, false,
                    "List all tests without running them.");
 
@@ -4243,12 +4257,67 @@ void StreamingListener::SocketWriter::MakeConnection() {
 const char* const OsStackTraceGetterInterface::kElidedFramesMarker =
     "... " GTEST_NAME_ " internal frames ...";
 
-std::string OsStackTraceGetter::CurrentStackTrace(int /*max_depth*/,
-                                                  int /*skip_count*/) {
+std::string OsStackTraceGetter::CurrentStackTrace(int max_depth, int skip_count)
+    GTEST_LOCK_EXCLUDED_(mutex_) {
+#if GTEST_HAS_ABSL
+  std::string result;
+
+  if (max_depth <= 0) {
+    return result;
+  }
+
+  max_depth = std::min(max_depth, kMaxStackTraceDepth);
+
+  std::vector<void*> raw_stack(max_depth);
+  // Skips the frames requested by the caller, plus this function.
+  const int raw_stack_size =
+      absl::GetStackTrace(&raw_stack[0], max_depth, skip_count + 1);
+
+  void* caller_frame = nullptr;
+  {
+    MutexLock lock(&mutex_);
+    caller_frame = caller_frame_;
+  }
+
+  for (int i = 0; i < raw_stack_size; ++i) {
+    if (raw_stack[i] == caller_frame &&
+        !GTEST_FLAG(show_internal_stack_frames)) {
+      // Add a marker to the trace and stop adding frames.
+      absl::StrAppend(&result, kElidedFramesMarker, "\n");
+      break;
+    }
+
+    char tmp[1024];
+    const char* symbol = "(unknown)";
+    if (absl::Symbolize(raw_stack[i], tmp, sizeof(tmp))) {
+      symbol = tmp;
+    }
+
+    char line[1024];
+    snprintf(line, sizeof(line), "  %p: %s\n", raw_stack[i], symbol);
+    result += line;
+  }
+
+  return result;
+
+#else  // !GTEST_HAS_ABSL
+  static_cast<void>(max_depth);
+  static_cast<void>(skip_count);
   return "";
+#endif  // GTEST_HAS_ABSL
 }
 
-void OsStackTraceGetter::UponLeavingGTest() {}
+void OsStackTraceGetter::UponLeavingGTest() GTEST_LOCK_EXCLUDED_(mutex_) {
+#if GTEST_HAS_ABSL
+  void* caller_frame = nullptr;
+  if (absl::GetStackTrace(&caller_frame, 1, 3) <= 0) {
+    caller_frame = nullptr;
+  }
+
+  MutexLock lock(&mutex_);
+  caller_frame_ = caller_frame;
+#endif  // GTEST_HAS_ABSL
+}
 
 // A helper class that creates the premature-exit file in its
 // constructor and deletes the file in its destructor.
@@ -4865,6 +4934,13 @@ void UnitTestImpl::PostFlagParsingInit() {
     // Configures listeners for streaming test results to the specified server.
     ConfigureStreamingOutput();
 #endif  // GTEST_CAN_STREAM_RESULTS_
+
+#if GTEST_HAS_ABSL
+    if (GTEST_FLAG(install_failure_signal_handler)) {
+      absl::FailureSignalHandlerOptions options;
+      absl::InstallFailureSignalHandler(options);
+    }
+#endif  // GTEST_HAS_ABSL
   }
 }
 
@@ -5769,6 +5845,10 @@ void InitGoogleTestImpl(int* argc, CharType** argv) {
     g_argvs.push_back(StreamableToString(argv[i]));
   }
 
+#if GTEST_HAS_ABSL
+  absl::InitializeSymbolizer(g_argvs[0].c_str());
+#endif  // GTEST_HAS_ABSL
+
   ParseGoogleTestFlagsOnly(argc, argv);
   GetUnitTestImpl()->PostFlagParsingInit();
 }

googletest/test/BUILD.bazel

@@ -34,7 +34,20 @@
 
 licenses(["notice"])
 
-""" gtest own tests """
+config_setting(
+    name = "windows",
+    values = {"cpu": "x64_windows"},
+)
+
+config_setting(
+    name = "windows_msvc",
+    values = {"cpu": "x64_windows_msvc"},
+)
+
+config_setting(
+    name = "has_absl",
+    values = {"define": "absl=1"},
+)
 
 #on windows exclude gtest-tuple.h and gtest-tuple_test.cc
 cc_test(
@@ -135,7 +148,6 @@ py_library(
     name = "gtest_test_utils",
     testonly = 1,
     srcs = ["gtest_test_utils.py"],
-
 )
 
 cc_binary(
@@ -144,6 +156,7 @@ cc_binary(
     srcs = ["gtest_help_test_.cc"],
     deps = ["//:gtest_main"],
 )
+
 py_test(
     name = "gtest_help_test",
     size = "small",
@@ -163,6 +176,10 @@ py_test(
     name = "gtest_output_test",
     size = "small",
     srcs = ["gtest_output_test.py"],
+    args = select({
+        ":has_absl": [],
+        "//conditions:default": ["--no_stacktrace_support"],
+    }),
     data = [
         "gtest_output_test_golden_lin.txt",
         ":gtest_output_test_",
@@ -176,6 +193,7 @@ cc_binary(
     srcs = ["gtest_color_test_.cc"],
     deps = ["//:gtest"],
 )
+
 py_test(
     name = "gtest_color_test",
     size = "small",
@@ -327,6 +345,10 @@ py_test(
         "gtest_xml_output_unittest.py",
         "gtest_xml_test_utils.py",
     ],
+    args = select({
+        ":has_absl": [],
+        "//conditions:default": ["--no_stacktrace_support"],
+    }),
     data = [
         # We invoke gtest_no_test_unittest to verify the XML output
         # when the test program contains no test definition.

googletest/test/gtest_output_test.py

@@ -52,6 +52,9 @@ import gtest_test_utils
 GENGOLDEN_FLAG = '--gengolden'
 CATCH_EXCEPTIONS_ENV_VAR_NAME = 'GTEST_CATCH_EXCEPTIONS'
 
+# The flag indicating stacktraces are not supported
+NO_STACKTRACE_SUPPORT_FLAG = '--no_stacktrace_support'
+
 IS_LINUX = os.name == 'posix' and os.uname()[0] == 'Linux'
 IS_WINDOWS = os.name == 'nt'
 
@@ -252,13 +255,12 @@ test_list = GetShellCommandOutput(COMMAND_LIST_TESTS)
 SUPPORTS_DEATH_TESTS = 'DeathTest' in test_list
 SUPPORTS_TYPED_TESTS = 'TypedTest' in test_list
 SUPPORTS_THREADS = 'ExpectFailureWithThreadsTest' in test_list
-SUPPORTS_STACK_TRACES = IS_LINUX
+SUPPORTS_STACK_TRACES = NO_STACKTRACE_SUPPORT_FLAG not in sys.argv
 
 CAN_GENERATE_GOLDEN_FILE = (SUPPORTS_DEATH_TESTS and
                             SUPPORTS_TYPED_TESTS and
                             SUPPORTS_THREADS and
-                            SUPPORTS_STACK_TRACES and
-                            not IS_WINDOWS)
+                            SUPPORTS_STACK_TRACES)
 
 class GTestOutputTest(gtest_test_utils.TestCase):
   def RemoveUnsupportedTests(self, test_output):
@@ -325,7 +327,11 @@ class GTestOutputTest(gtest_test_utils.TestCase):
 
 
 if __name__ == '__main__':
-  if sys.argv[1:] == [GENGOLDEN_FLAG]:
+  if NO_STACKTRACE_SUPPORT_FLAG in sys.argv:
+    # unittest.main() can't handle unknown flags
+    sys.argv.remove(NO_STACKTRACE_SUPPORT_FLAG)
+
+  if GENGOLDEN_FLAG in sys.argv:
     if CAN_GENERATE_GOLDEN_FILE:
       output = GetOutputOfAllCommands()
       golden_file = open(GOLDEN_PATH, 'wb')

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">