Add simple runtime benchmarks

For now we add just two binaries, one with assertions taking the
fast path, one with assertions taking the slow path, and the ability
to run 1 of `REQUIRE(true)`, `REQUIRE_NOTHROW`, `REQUIRE_THROWS`
in a loop.

I also split off a CMake preset which enables more tests than the
basic `simple-tests` preset, but does not enable the most expensive
tests which force recompilation of Catch2 multiple times.

CMakeLists.txt

@@ -20,6 +20,7 @@ cmake_dependent_option(CATCH_BUILD_TESTING "Build the SelfTest project" ON "CATC
 cmake_dependent_option(CATCH_BUILD_EXAMPLES "Build code examples" OFF "CATCH_DEVELOPMENT_BUILD" OFF)
 cmake_dependent_option(CATCH_BUILD_EXTRA_TESTS "Build extra tests" OFF "CATCH_DEVELOPMENT_BUILD" OFF)
 cmake_dependent_option(CATCH_BUILD_FUZZERS "Build fuzzers" OFF "CATCH_DEVELOPMENT_BUILD" OFF)
+cmake_dependent_option(CATCH_BUILD_BENCHMARKS "Build the benchmarks" OFF "CATCH_DEVELOPMENT_BUILD" OFF)
 cmake_dependent_option(CATCH_ENABLE_COVERAGE "Generate coverage for codecov.io" OFF "CATCH_DEVELOPMENT_BUILD" OFF)
 cmake_dependent_option(CATCH_ENABLE_WERROR "Enables Werror during build" ON "CATCH_DEVELOPMENT_BUILD" OFF)
 cmake_dependent_option(CATCH_BUILD_SURROGATES "Enable generating and building surrogate TUs for the main headers" OFF "CATCH_DEVELOPMENT_BUILD" OFF)
@@ -77,6 +78,11 @@ set(SELF_TEST_DIR ${CATCH_DIR}/tests/SelfTest)
 # We need to bring-in the variables defined there to this scope
 add_subdirectory(src)
 
+if (CATCH_BUILD_BENCHMARKS)
+  set(CMAKE_FOLDER "benchmarks")
+  add_subdirectory(benchmarks)
+endif()
+
 # Build tests only if requested
 if(BUILD_TESTING AND CATCH_BUILD_TESTING AND NOT_SUBPROJECT)
   find_package(Python3 REQUIRED COMPONENTS Interpreter)

CMakePresets.json

@@ -15,14 +15,23 @@
             }
         },
         {
-            "name": "all-tests",
+            "name": "most-tests",
             "inherits": "basic-tests",
             "displayName": "Full development build",
-            "description": "Enables development build with examples and ALL tests",
+            "description": "Enables development build with extended set of tests (still relatively cheap to build)",
             "cacheVariables": {
                 "CATCH_BUILD_EXAMPLES": "ON",
                 "CATCH_BUILD_EXTRA_TESTS": "ON",
                 "CATCH_BUILD_SURROGATES": "ON",
+                "CATCH_BUILD_BENCHMARKS": "ON"
+            }
+        },
+        {
+            "name": "all-tests",
+            "inherits": "most-tests",
+            "displayName": "Full development build",
+            "description": "Enables development build with examples and ALL tests",
+            "cacheVariables": {
                 "CATCH_ENABLE_CONFIGURE_TESTS": "ON",
                 "CATCH_ENABLE_CMAKE_HELPER_TESTS": "ON"
             }

README-2.md

@@ -1,109 +0,0 @@
-<a id="top"></a>
-
-<table width="100%">
-  <tr>
-    <td align="center" width="50%"><img src="/data/artwork/catch2-logo-full-with-background.svg" width="100%"></td>
-    <td align="center" width="50%"><figure><figcaption>Special thanks to:</figcaption><img src="/data/sponsors/github_repo_sponsorship-inverted.png" width="100%"></figure></td>
-  </tr>
-</table>
-
-[![Github Releases](https://img.shields.io/github/release/catchorg/catch2.svg)](https://github.com/catchorg/catch2/releases)
-[![Linux build status](https://github.com/catchorg/Catch2/actions/workflows/linux-simple-builds.yml/badge.svg)](https://github.com/catchorg/Catch2/actions/workflows/linux-simple-builds.yml)
-[![Linux build status](https://github.com/catchorg/Catch2/actions/workflows/linux-other-builds.yml/badge.svg)](https://github.com/catchorg/Catch2/actions/workflows/linux-other-builds.yml)
-[![MacOS build status](https://github.com/catchorg/Catch2/actions/workflows/mac-builds.yml/badge.svg)](https://github.com/catchorg/Catch2/actions/workflows/mac-builds.yml)
-[![Build Status](https://ci.appveyor.com/api/projects/status/github/catchorg/Catch2?svg=true&branch=devel)](https://ci.appveyor.com/project/catchorg/catch2)
-[![Code Coverage](https://codecov.io/gh/catchorg/Catch2/branch/devel/graph/badge.svg)](https://codecov.io/gh/catchorg/Catch2)
-[![Try online](https://img.shields.io/badge/try-online-blue.svg)](https://godbolt.org/z/EdoY15q9G)
-[![Join the chat in Discord: https://discord.gg/4CWS9zD](https://img.shields.io/badge/Discord-Chat!-brightgreen.svg)](https://discord.gg/4CWS9zD)
-
-
-## What is Catch2?
-
-Catch2 is mainly a unit testing framework for C++, but it also
-provides basic micro-benchmarking features, and simple BDD macros.
-
-Catch2's main advantage is that using it is both simple and natural.
-Test names do not have to be valid identifiers, assertions look like
-normal C++ boolean expressions, and sections provide a nice and local way
-to share set-up and tear-down code in tests.
-
-**Example unit test**
-```cpp
-#include <catch2/catch_test_macros.hpp>
-
-#include <cstdint>
-
-uint32_t factorial( uint32_t number ) {
-    return number <= 1 ? number : factorial(number-1) * number;
-}
-
-TEST_CASE( "Factorials are computed", "[factorial]" ) {
-    REQUIRE( factorial( 1) == 1 );
-    REQUIRE( factorial( 2) == 2 );
-    REQUIRE( factorial( 3) == 6 );
-    REQUIRE( factorial(10) == 3'628'800 );
-}
-```
-
-**Example microbenchmark**
-```cpp
-#include <catch2/catch_test_macros.hpp>
-#include <catch2/benchmark/catch_benchmark.hpp>
-
-#include <cstdint>
-
-uint64_t fibonacci(uint64_t number) {
-    return number < 2 ? number : fibonacci(number - 1) + fibonacci(number - 2);
-}
-
-TEST_CASE("Benchmark Fibonacci", "[!benchmark]") {
-    REQUIRE(fibonacci(5) == 5);
-
-    REQUIRE(fibonacci(20) == 6'765);
-    BENCHMARK("fibonacci 20") {
-        return fibonacci(20);
-    };
-
-    REQUIRE(fibonacci(25) == 75'025);
-    BENCHMARK("fibonacci 25") {
-        return fibonacci(25);
-    };
-}
-```
-
-_Note that benchmarks are not run by default, so you need to run it explicitly
-with the `[!benchmark]` tag._
-
-
-## Catch2 v3 has been released!
-
-You are on the `devel` branch, where the v3 version is being developed.
-v3 brings a bunch of significant changes, the big one being that Catch2
-is no longer a single-header library. Catch2 now behaves as a normal
-library, with multiple headers and separately compiled implementation.
-
-The documentation is slowly being updated to take these changes into
-account, but this work is currently still ongoing.
-
-For migrating from the v2 releases to v3, you should look at [our
-documentation](docs/migrate-v2-to-v3.md#top). It provides a simple
-guidelines on getting started, and collects most common migration
-problems.
-
-For the previous major version of Catch2 [look into the `v2.x` branch
-here on GitHub](https://github.com/catchorg/Catch2/tree/v2.x).
-
-
-## How to use it
-This documentation comprises these three parts:
-
-* [Why do we need yet another C++ Test Framework?](docs/why-catch.md#top)
-* [Tutorial](docs/tutorial.md#top) - getting started
-* [Reference section](docs/Readme.md#top) - all the details
-
-
-## More
-* Issues and bugs can be raised on the [Issue tracker on GitHub](https://github.com/catchorg/Catch2/issues)
-* For discussion or questions please use [our Discord](https://discord.gg/4CWS9zD)
-* See who else is using Catch2 in [Open Source Software](docs/opensource-users.md#top)
-or [commercially](docs/commercial-users.md#top).

README.md

@@ -1,11 +1,5 @@
 <a id="top"></a>
-
+![Catch2 logo](data/artwork/catch2-logo-full-with-background.svg)
-<table width="100%">
-  <tr>
-    <td align="center" width="50%"><img src="/data/artwork/catch2-logo-full-with-background.svg" width="100%"></td>
-    <td align="center" width="50%"><figure><figcaption>Special thanks to:</figcaption><img src="/data/sponsors/github_repo_sponsorship.png" width="100%"></figure></td>
-  </tr>
-</table>
 
 [![Github Releases](https://img.shields.io/github/release/catchorg/catch2.svg)](https://github.com/catchorg/catch2/releases)
 [![Linux build status](https://github.com/catchorg/Catch2/actions/workflows/linux-simple-builds.yml/badge.svg)](https://github.com/catchorg/Catch2/actions/workflows/linux-simple-builds.yml)

benchmarks/CMakeLists.txt

@@ -0,0 +1,16 @@
+include(CatchMiscFunctions)
+
+add_executable(AssertionsFastPath
+  runtime_assertion_benches.cpp
+)
+
+add_executable(AssertionsSlowPath
+  runtime_assertion_benches.cpp
+  assertion_listener.cpp
+)
+
+target_link_libraries(AssertionsFastPath PRIVATE Catch2::Catch2WithMain)
+target_link_libraries(AssertionsSlowPath PRIVATE Catch2::Catch2WithMain)
+
+list(APPEND CATCH_TEST_TARGETS AssertionsFastPath AssertionsSlowPath)
+set(CATCH_TEST_TARGETS ${CATCH_TEST_TARGETS} PARENT_SCOPE)

benchmarks/assertion_listener.cpp

@@ -0,0 +1,28 @@
+
+//              Copyright Catch2 Authors
+// Distributed under the Boost Software License, Version 1.0.
+//   (See accompanying file LICENSE.txt or copy at
+//        https://www.boost.org/LICENSE_1_0.txt)
+
+// SPDX-License-Identifier: BSL-1.0
+
+#include <catch2/reporters/catch_reporter_event_listener.hpp>
+#include <catch2/reporters/catch_reporter_registrars.hpp>
+
+/**
+ * Event listener that listens to all assertions, forcing assertion slow path
+ */
+class AssertionSlowPathListener : public Catch::EventListenerBase {
+public:
+    static std::string getDescription() {
+        return "Validates ordering of Catch2's listener events";
+    }
+
+    AssertionSlowPathListener(Catch::IConfig const* config) :
+        EventListenerBase(config) {
+        m_preferences.shouldReportAllAssertions = true;
+        m_preferences.shouldReportAllAssertionStarts = true;
+    }
+};
+
+CATCH_REGISTER_LISTENER( AssertionSlowPathListener )

benchmarks/runtime_assertion_benches.cpp

@@ -0,0 +1,27 @@
+
+//              Copyright Catch2 Authors
+// Distributed under the Boost Software License, Version 1.0.
+//   (See accompanying file LICENSE.txt or copy at
+//        https://www.boost.org/LICENSE_1_0.txt)
+
+// SPDX-License-Identifier: BSL-1.0
+
+#include <catch2/catch_test_macros.hpp>
+
+TEST_CASE("Simple REQUIRE - 10M") {
+    for (size_t i = 0; i < 10'000'000; ++i) {
+        REQUIRE(true);
+    }
+}
+
+TEST_CASE("Simple NOTHROW - 10M") {
+    for (size_t i = 0; i < 10'000'000; ++i) {
+        REQUIRE_NOTHROW([](){}());
+    }
+}
+
+TEST_CASE("Simple THROWS - 10M") {
+    for (size_t i = 0; i < 10'000'000; ++i) {
+        REQUIRE_THROWS([]() { throw 1; }());
+    }
+}

docs/ci-and-misc.md

@@ -66,11 +66,14 @@ test execution. Specifically it understands
  * JUnit output path via `XML_OUTPUT_FILE`
  * Test filtering via `TESTBRIDGE_TEST_ONLY`
  * Test sharding via `TEST_SHARD_INDEX`, `TEST_TOTAL_SHARDS`, and `TEST_SHARD_STATUS_FILE`
+ * Creating a file to signal premature test exit via `TEST_PREMATURE_EXIT_FILE`
 
 > Support for `XML_OUTPUT_FILE` was [introduced](https://github.com/catchorg/Catch2/pull/2399) in Catch2 3.0.1
 
 > Support for `TESTBRIDGE_TEST_ONLY` and sharding was introduced in Catch2 3.2.0
 
+> Support for `TEST_PREMATURE_EXIT_FILE` was introduced in Catch2 X.Y.Z
+
 This integration is enabled via either a [compile time configuration
 option](configuration.md#bazel-support), or via `BAZEL_TEST` environment
 variable set to "1".

docs/command-line.md

@@ -32,6 +32,7 @@
 [Test Sharding](#test-sharding)<br>
 [Allow running the binary without tests](#allow-running-the-binary-without-tests)<br>
 [Output verbosity](#output-verbosity)<br>
+[Create file to guard against silent early termination](#create-file-to-guard-against-silent-early-termination)<br>
 
 Catch works quite nicely without any command line options at all - but for those times when you want greater control the following options are available.
 Click one of the following links to take you straight to that option - or scroll on to browse the available options.
@@ -649,6 +650,21 @@ ignored.
 Verbosity defaults to _normal_.
 
 
+## Create file to guard against silent early termination
+<pre>--premature-exit-guard-file &lt;path&gt;</pre>
+
+> Introduced in Catch2 X.Y.Z
+
+Tells Catch2 to create an empty file at specified path before the tests
+start, and delete it after the tests finish. If the file is present after
+the process stops, it can be assumed that the testing binary exited
+prematurely, e.g. due to the OOM killer.
+
+All directories in the path must already exist. If this option is used
+and Catch2 cannot create the file (e.g. the location is not writable),
+the test run will fail.
+
+
 ---
 
 [Home](Readme.md#top)

src/catch2/catch_message.cpp

@@ -22,7 +22,7 @@ namespace Catch {
         m_messageId( builder.m_info.sequence ) {
         MessageInfo info( CATCH_MOVE( builder.m_info ) );
         info.message = builder.m_stream.str();
-        getResultCapture().pushScopedMessage( CATCH_MOVE(info) );
+        IResultCapture::pushScopedMessage( CATCH_MOVE( info ) );
     }
 
     ScopedMessage::ScopedMessage( ScopedMessage&& old ) noexcept:
@@ -31,15 +31,14 @@ namespace Catch {
     }
 
     ScopedMessage::~ScopedMessage() {
-        if ( !m_moved ) { getResultCapture().popScopedMessage( m_messageId ); }
+        if ( !m_moved ) { IResultCapture::popScopedMessage( m_messageId ); }
     }
 
 
     Capturer::Capturer( StringRef macroName,
                         SourceLineInfo const& lineInfo,
                         ResultWas::OfType resultType,
-                        StringRef names ):
+                        StringRef names ) {
-        m_resultCapture( getResultCapture() ) {
         auto trimmed = [&] (size_t start, size_t end) {
             while (names[start] == ',' || isspace(static_cast<unsigned char>(names[start]))) {
                 ++start;
@@ -101,14 +100,14 @@ namespace Catch {
     Capturer::~Capturer() {
         assert( m_captured == m_messages.size() );
         for (auto const& message : m_messages) {
-            m_resultCapture.popScopedMessage( message.sequence );
+            IResultCapture::popScopedMessage( message.sequence );
         }
     }
 
     void Capturer::captureValue( size_t index, std::string const& value ) {
         assert( index < m_messages.size() );
         m_messages[index].message += value;
-        m_resultCapture.pushScopedMessage( CATCH_MOVE(m_messages[index]) );
+        IResultCapture::pushScopedMessage( CATCH_MOVE( m_messages[index] ) );
         m_captured++;
     }
 

src/catch2/catch_message.hpp

@@ -63,7 +63,6 @@ namespace Catch {
 
     class Capturer {
         std::vector<MessageInfo> m_messages;
-        IResultCapture& m_resultCapture;
         size_t m_captured = 0;
     public:
         Capturer( StringRef macroName, SourceLineInfo const& lineInfo, ResultWas::OfType resultType, StringRef names );
@@ -111,7 +110,7 @@ namespace Catch {
 
 ///////////////////////////////////////////////////////////////////////////////
 #define INTERNAL_CATCH_UNSCOPED_INFO( macroName, log ) \
-    Catch::getResultCapture().emplaceUnscopedMessage( Catch::MessageBuilder( macroName##_catch_sr, CATCH_INTERNAL_LINEINFO, Catch::ResultWas::Info ) << log )
+    Catch::IResultCapture::emplaceUnscopedMessage( Catch::MessageBuilder( macroName##_catch_sr, CATCH_INTERNAL_LINEINFO, Catch::ResultWas::Info ) << log )
 
 
 #if defined(CATCH_CONFIG_PREFIX_MESSAGES) && !defined(CATCH_CONFIG_DISABLE)

src/catch2/interfaces/catch_interfaces_capture.hpp

@@ -62,10 +62,9 @@ namespace Catch {
         virtual void benchmarkEnded( BenchmarkStats<> const& stats ) = 0;
         virtual void benchmarkFailed( StringRef error ) = 0;
 
-        virtual void pushScopedMessage( MessageInfo&& message ) = 0;
+        static void pushScopedMessage( MessageInfo&& message );
-        virtual void popScopedMessage( unsigned int messageId ) = 0;
+        static void popScopedMessage( unsigned int messageId );
-
+        static void emplaceUnscopedMessage( MessageBuilder&& builder );
-        virtual void emplaceUnscopedMessage( MessageBuilder&& builder ) = 0;
 
         virtual void handleFatalErrorCondition( StringRef message ) = 0;
 
@@ -102,6 +101,7 @@ namespace Catch {
     };
 
     IResultCapture& getResultCapture();
+
 }
 
 #endif // CATCH_INTERFACES_CAPTURE_HPP_INCLUDED

src/catch2/internal/catch_compiler_capabilities.hpp

@@ -220,13 +220,17 @@
 #    endif
 
 // Universal Windows platform does not support SEH
-// Or console colours (or console at all...)
+#  if !defined(CATCH_PLATFORM_WINDOWS_UWP)
-#  if defined(CATCH_PLATFORM_WINDOWS_UWP)
-#    define CATCH_INTERNAL_CONFIG_NO_COLOUR_WIN32
-#  else
 #    define CATCH_INTERNAL_CONFIG_WINDOWS_SEH
 #  endif
 
+// Only some Windows platform families support the console
+#  if defined(WINAPI_FAMILY_PARTITION)
+#    if !WINAPI_FAMILY_PARTITION(WINAPI_PARTITION_APP | WINAPI_PARTITION_SYSTEM)
+#      define CATCH_INTERNAL_CONFIG_NO_COLOUR_WIN32
+#    endif
+#  endif
+
 // MSVC traditional preprocessor needs some workaround for __VA_ARGS__
 // _MSVC_TRADITIONAL == 0 means new conformant preprocessor
 // _MSVC_TRADITIONAL == 1 means old traditional non-conformant preprocessor

src/catch2/internal/catch_console_colour.cpp

@@ -161,7 +161,11 @@ namespace {
 #endif // Windows/ ANSI/ None
 
 
-#if defined( CATCH_PLATFORM_LINUX ) || defined( CATCH_PLATFORM_MAC ) || defined( __GLIBC__ ) || defined(__FreeBSD__)
+#if defined( CATCH_PLATFORM_LINUX ) \
+ || defined( CATCH_PLATFORM_MAC ) \
+ || defined( __GLIBC__ ) \
+ || defined( __FreeBSD__ ) \
+ || defined( CATCH_PLATFORM_QNX )
 #    define CATCH_INTERNAL_HAS_ISATTY
 #    include <unistd.h>
 #endif

src/catch2/internal/catch_debugger.cpp

@@ -69,7 +69,7 @@
         #endif
     } // namespace Catch
 
-#elif defined(CATCH_PLATFORM_LINUX)
+#elif defined(CATCH_PLATFORM_LINUX) || defined(CATCH_PLATFORM_QNX)
     #include <fstream>
     #include <string>
 

src/catch2/internal/catch_debugger.hpp

@@ -49,7 +49,7 @@ namespace Catch {
         #define CATCH_TRAP()  __asm__(".inst 0xde01")
     #endif
 
-#elif defined(CATCH_PLATFORM_LINUX)
+#elif defined(CATCH_PLATFORM_LINUX) || defined(CATCH_PLATFORM_QNX)
     // If we can use inline assembler, do it because this allows us to break
     // directly at the location of the failing check instead of breaking inside
     // raise() called from it, i.e. one stack frame below.

src/catch2/internal/catch_platform.hpp

@@ -25,6 +25,9 @@
 #elif defined(linux) || defined(__linux) || defined(__linux__)
 #  define CATCH_PLATFORM_LINUX
 
+#elif defined(__QNX__)
+#  define CATCH_PLATFORM_QNX
+
 #elif defined(WIN32) || defined(__WIN32__) || defined(_WIN32) || defined(_MSC_VER) || defined(__MINGW32__)
 #  define CATCH_PLATFORM_WINDOWS
 

src/catch2/internal/catch_run_context.cpp

@@ -483,28 +483,6 @@ namespace Catch {
         m_reporter->benchmarkFailed( error );
     }
 
-    void RunContext::pushScopedMessage( MessageInfo&& message ) {
-        Detail::g_messages.push_back( CATCH_MOVE(message) );
-    }
-
-    void RunContext::popScopedMessage( unsigned int messageId ) {
-        // Note: On average, it would probably be better to look for the message
-        //       backwards. However, we do not expect to have to deal with more
-        //       messages than low single digits, so the optimization is tiny,
-        //       and we would have to hand-write the loop to avoid terrible
-        //       codegen of reverse iterators in debug mode.
-        Detail::g_messages.erase(
-            std::find_if( Detail::g_messages.begin(),
-                          Detail::g_messages.end(),
-                          [=]( MessageInfo const& msg ) {
-                              return msg.sequence == messageId;
-                          } ) );
-    }
-
-    void RunContext::emplaceUnscopedMessage( MessageBuilder&& builder ) {
-        Detail::g_messageScopes.emplace_back( CATCH_MOVE(builder) );
-    }
-
     std::string RunContext::getCurrentTestName() const {
         return m_activeTestCase
             ? m_activeTestCase->getTestCaseInfo().name
@@ -838,6 +816,28 @@ namespace Catch {
             CATCH_INTERNAL_ERROR("No result capture instance");
     }
 
+    void IResultCapture::pushScopedMessage( MessageInfo&& message ) {
+        Detail::g_messages.push_back( CATCH_MOVE( message ) );
+    }
+
+    void IResultCapture::popScopedMessage( unsigned int messageId ) {
+        // Note: On average, it would probably be better to look for the message
+        //       backwards. However, we do not expect to have to deal with more
+        //       messages than low single digits, so the optimization is tiny,
+        //       and we would have to hand-write the loop to avoid terrible
+        //       codegen of reverse iterators in debug mode.
+        Detail::g_messages.erase( std::find_if( Detail::g_messages.begin(),
+                                                Detail::g_messages.end(),
+                                                [=]( MessageInfo const& msg ) {
+                                                    return msg.sequence ==
+                                                           messageId;
+                                                } ) );
+    }
+
+    void IResultCapture::emplaceUnscopedMessage( MessageBuilder&& builder ) {
+        Detail::g_messageScopes.emplace_back( CATCH_MOVE( builder ) );
+    }
+
     void seedRng(IConfig const& config) {
         sharedRng().seed(config.rngSeed());
     }

src/catch2/internal/catch_run_context.hpp

@@ -94,11 +94,6 @@ namespace Catch {
         void benchmarkEnded( BenchmarkStats<> const& stats ) override;
         void benchmarkFailed( StringRef error ) override;
 
-        void pushScopedMessage( MessageInfo&& message ) override;
-        void popScopedMessage( unsigned int messageId ) override;
-
-        void emplaceUnscopedMessage( MessageBuilder&& builder ) override;
-
         std::string getCurrentTestName() const override;
 
         const AssertionResult* getLastResult() const override;

tests/ExtraTests/CMakeLists.txt

@@ -95,7 +95,7 @@ foreach(target DisabledExceptions-DefaultHandler DisabledExceptions-CustomHandle
   target_compile_options(${target}
     PUBLIC
       $<$<CXX_COMPILER_ID:MSVC>:/EHs-c-;/D_HAS_EXCEPTIONS=0>
-      $<$<OR:$<CXX_COMPILER_ID:Clang>,$<CXX_COMPILER_ID:GNU>,$<CXX_COMPILER_ID:AppleClang>>:-fno-exceptions>
+      $<$<OR:$<CXX_COMPILER_ID:Clang>,$<CXX_COMPILER_ID:GNU>,$<CXX_COMPILER_ID:QCC>,$<CXX_COMPILER_ID:AppleClang>>:-fno-exceptions>
   )
   target_link_libraries(${target} Catch2_buildall_interface)
 endforeach()
@@ -429,6 +429,50 @@ set_tests_properties(Reporters::CrashInJunitReporter
     LABELS "uses-signals"
 )
 
+
+add_executable(QuickExitInTest ${TESTS_DIR}/X40-QuickExit.cpp)
+target_link_libraries(QuickExitInTest PRIVATE Catch2::Catch2WithMain)
+add_test(
+  NAME BazelEnv::TEST_PREMATURE_EXIT_FILE
+  COMMAND
+    Python3::Interpreter
+    "${CATCH_DIR}/tests/TestScripts/testBazelExitGuardFile.py"
+    $<TARGET_FILE:QuickExitInTest>
+    "${CMAKE_CURRENT_BINARY_DIR}"
+    "bazel"
+)
+set_tests_properties(BazelEnv::TEST_PREMATURE_EXIT_FILE
+  PROPERTIES
+    LABELS "uses-python"
+)
+add_test(
+  NAME PrematureExitGuardFileCanBeUsedFromCLI::CheckAfterCrash
+  COMMAND
+    Python3::Interpreter
+    "${CATCH_DIR}/tests/TestScripts/testBazelExitGuardFile.py"
+    $<TARGET_FILE:QuickExitInTest>
+    "${CMAKE_CURRENT_BINARY_DIR}"
+    "cli"
+)
+set_tests_properties(PrematureExitGuardFileCanBeUsedFromCLI::CheckAfterCrash
+  PROPERTIES
+    LABELS "uses-python"
+)
+add_test(
+  NAME PrematureExitGuardFileCanBeUsedFromCLI::CheckWithoutCrash
+  COMMAND
+    Python3::Interpreter
+    "${CATCH_DIR}/tests/TestScripts/testBazelExitGuardFile.py"
+    $<TARGET_FILE:QuickExitInTest>
+    "${CMAKE_CURRENT_BINARY_DIR}"
+    "no-crash"
+)
+set_tests_properties(PrematureExitGuardFileCanBeUsedFromCLI::CheckWithoutCrash
+  PROPERTIES
+    LABELS "uses-python"
+)
+
+
 add_executable(AssertionStartingEventGoesBeforeAssertionIsEvaluated
   X20-AssertionStartingEventGoesBeforeAssertionIsEvaluated.cpp
 )

tests/ExtraTests/X40-QuickExit.cpp

@@ -0,0 +1,28 @@
+
+//              Copyright Catch2 Authors
+// Distributed under the Boost Software License, Version 1.0.
+//   (See accompanying file LICENSE.txt or copy at
+//        https://www.boost.org/LICENSE_1_0.txt)
+
+// SPDX-License-Identifier: BSL-1.0
+
+/**\file
+ * Call ~~quick_exit~~ inside a test.
+ *
+ * This is used to test whether Catch2 properly creates the crash guard
+ * file based on provided arguments.
+ */
+
+#include <catch2/catch_test_macros.hpp>
+
+#include <cstdlib>
+
+TEST_CASE("quick_exit", "[quick_exit]") {
+    // Return 0 as fake "successful" exit, while there should be a guard
+    // file created and kept.
+    std::exit(0);
+    // We cannot use quick_exit because libstdc++ on older MacOS versions didn't support it yet.
+    // std::quick_exit(0);
+}
+
+TEST_CASE("pass") {}

tests/TestScripts/testBazelExitGuardFile.py

@@ -0,0 +1,88 @@
+#!/usr/bin/env python3
+
+#              Copyright Catch2 Authors
+# Distributed under the Boost Software License, Version 1.0.
+#   (See accompanying file LICENSE.txt or copy at
+#        https://www.boost.org/LICENSE_1_0.txt)
+
+# SPDX-License-Identifier: BSL-1.0
+
+import os
+import sys
+import subprocess
+
+def generate_path_suffix() -> str:
+    return os.urandom(16).hex()[:16]
+
+
+def run_common(cmd, env = None):
+    cmd_env = env if env is not None else os.environ.copy()
+    print('Running:', cmd)
+
+    try:
+        ret = subprocess.run(
+            cmd,
+            stdout=subprocess.PIPE,
+            stderr=subprocess.PIPE,
+            check=True,
+            universal_newlines=True,
+            env=cmd_env
+        )
+    except subprocess.SubprocessError as ex:
+        print('Could not run "{}"'.format(cmd))
+        print("Return code: {}".format(ex.returncode))
+        print("stdout: {}".format(ex.stdout))
+        print("stderr: {}".format(ex.stderr))
+        raise
+
+
+def test_bazel_env_vars(bin_path, guard_path):
+    env = os.environ.copy()
+    env["TEST_PREMATURE_EXIT_FILE"] = guard_path
+    env["BAZEL_TEST"] = '1'
+    run_common([bin_path], env)
+
+def test_cli_parameter(bin_path, guard_path):
+    cmd = [
+      bin_path,
+      '--premature-exit-guard-file',
+      guard_path
+    ]
+    run_common(cmd)
+
+def test_no_crash(bin_path, guard_path):
+    cmd = [
+      bin_path,
+      '--premature-exit-guard-file',
+      guard_path,
+      # Disable the quick-exit test
+      '~[quick_exit]'
+    ]
+    run_common(cmd)
+
+checks = {
+  'bazel': (test_bazel_env_vars, True),
+  'cli': (test_cli_parameter, True),
+  'no-crash': (test_no_crash, False),
+}
+
+
+bin_path = os.path.abspath(sys.argv[1])
+output_dir = os.path.abspath(sys.argv[2])
+test_kind = sys.argv[3]
+guard_file_path = os.path.join(output_dir, f"guard_file.{generate_path_suffix()}")
+print(f'Guard file path: "{guard_file_path}"')
+
+check_func, file_should_exist = checks[test_kind]
+check_func(bin_path, guard_file_path)
+
+assert os.path.exists(guard_file_path) == file_should_exist
+# With randomly generated file suffix, we should not run into name conflicts.
+# However, we try to cleanup anyway, to avoid having infinity files in
+# long living build directories.
+if file_should_exist:
+    try:
+        os.remove(guard_file_path)
+    except Exception as ex:
+        print(f'Could not remove file {guard_file_path} because: {ex}')
+