Merge pull request #4 from Progmasoft/backport/upstream-3.16.1

Backport Catch2 3.16.1

42 files changed, 840 insertions, 455 deletions

diff --git a/.github/workflows/mac-builds.yml b/.github/workflows/mac-builds.yml
index 7ba8dac5..7162646b 100644
--- a/.github/workflows/mac-builds.yml
+++ b/.github/workflows/mac-builds.yml
@@ -15,7 +15,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        image: [macos-14, macos-15, macos-15-intel]
+        image: [macos-15, macos-15-intel]
         build_type: [Debug, Release]
         std: [14, 17]
 
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 291af7c5..a8f1da6d 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -35,7 +35,7 @@ if(CMAKE_BINARY_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR)
 endif()
 
 project(Catch2
-  VERSION 3.16.0 # CML version placeholder, don't delete
+  VERSION 3.16.1 # CML version placeholder, don't delete
   LANGUAGES CXX
   HOMEPAGE_URL "https://github.com/catchorg/Catch2"
   DESCRIPTION "A modern, C++-native, unit test framework."
diff --git a/README.md b/README.md
index fae1e037..d1ef75e0 100644
--- a/README.md
+++ b/README.md
@@ -10,7 +10,7 @@ owned C++20 library for property checks, snapshots, structured results, and XML
 serialization.
 
 > Catch3 is not an official Catch2 release and is not endorsed by Catch2's
-> maintainers. Its current compatibility engine is based on Catch2 3.16.0;
+> maintainers. Its current compatibility engine is based on Catch2 3.16.1;
 > upstream-originated files keep their upstream license. Progmasoft-authored
 > additions have their own licensing terms. See [the project scope and
 > compatibility notes](docs/why-catch3.md).
diff --git a/docs/deprecations.md b/docs/deprecations.md
index 3915ddbc..82f044cc 100644
--- a/docs/deprecations.md
+++ b/docs/deprecations.md
@@ -62,6 +62,16 @@ specified the filters through the new `-p/--path-filter` parameter, which
 means that generators are taken into account.
 
 
+### Reporter event handling functions without noexcept
+
+> Deprecated in Catch2 3.16.1
+
+Catch2 does not try to support reporters throwing from arbitrary
+`fooStarting` or `fooEnded` test running event. For legacy reasons, the
+event listener interface is declared without `noexcept`, but in the future
+it will be changed to use `noexcept` to make this limitation explicit.
+
+
 ### Generator interfaces
 
 #### Defaulted `UntypedGeneratorBase::isFinite()`
diff --git a/docs/release-notes.md b/docs/release-notes.md
index 3a2c7734..2ba3b663 100644
--- a/docs/release-notes.md
+++ b/docs/release-notes.md
@@ -5,6 +5,7 @@
 
 # Release notes
 **Contents**<br>
+[3.16.1](#3161)<br>
 [3.16.0](#3160)<br>
 [3.15.3](#3153)<br>
 [3.15.2](#3152)<br>
@@ -82,6 +83,40 @@
 [Even Older versions](#even-older-versions)<br>
 
 
+## 3.16.1
+
+### Fixes
+* Fixed optimizations being disabled after including benchmarking headers under MSVC. (#3212)
+  * This was introduced in 3.16.0's fix for the deopt implementation for MSVC never being used.
+* Fixed Console reporter replacing `\0xFF`s in user-provided strings.
+* Added missing `<cassert>` include to `catch_generators_range.hpp`. (#3205)
+
+### Improvements
+* Workaround for GCC's quadratic scaling for release builds with number of test cases.
+  * In practice the improvement is only noticeable with unity builds and/or template product tests.
+* Changed how decomposer operators are defined for better compilation times.
+  * For Catch2's `SelfTest` binary, this provides ~2% build time improvement.
+* Changed how decomposer handles stringification for smaller binary sizes.
+  * For the `SelfTest` binary this is about ~8%.
+* Improved compilation costs of multiple assertions in one test cases for release builds.
+* Optimized initial test registration at process start:
+  * Fewer allocations for test cases with many tags.
+  * Faster processing for test cases with <=2 tags.
+  * Faster tag validation.
+  * Faster checking for duplicated test cases.
+* Optimized test selection and filtering:
+* Optimized filtering tests by test name.
+  * Running `SelfTest` with `abc*` as the filter pattern is ~10% faster.
+
+### Miscellaneous
+* `catch_discover_tests` registers individual tests with `--order decl` for faster startup.
+  * For `SelfTest`, this provides 20% improvement in Debug and 5% in Release builds.
+* `CMakeConfig::` family of tests use the main build's toolchain file. (#3202)
+* Deprecated throwing exceptions from the reporter interface functions.
+  * Previously, throwing from e.g. `assertionEnded` might, or might not, have worked depending on which assertion has ended. As it is not practical for Catch2 to guard against the reporters failing randomly, and marking so with `noexcept` can provide compilation throughput improvements, I decided to fully forbid it.
+  * Reporter constructors are allowed to throw and the test binary will report the error nicely before exiting.
+  * Due to C++ limitations, this deprecation cannot be marked inside the code, only in docs.
+
 
 ## 3.16.0
 
diff --git a/docs/upstream-status.md b/docs/upstream-status.md
index 99182ad7..ac87b654 100644
--- a/docs/upstream-status.md
+++ b/docs/upstream-status.md
@@ -13,6 +13,33 @@ licenses or compiler options:
 - `222e233903d287cda4713fb08e1a959e8d71fd6d`: isolate Clang's pointer-to-bool
   diagnostic at the upstream reusable-string-stream compatibility boundary.
 
+The branch was reviewed again through
+`08092139210881f01a34e60c5f2fd6afa0ea4024`, the commit of Catch2 3.16.1, on
+2026-10-11. The eleven changes since the previous reviewed revision were all
+backported, in upstream order, and the compatibility engine is now 3.16.1:
+
+- `d7683484`: a better message when a reporter cannot be initialized.
+- `ea5020f0`: every first-party reporter validates its custom arguments.
+- `aa01559e`: the throwing-reporter test also throws in `assertionEnded`.
+- `45cd3987`: `handleUnexpectedInflightException` is `noexcept`.
+- `6adbd539`: MSVC optimizations are enabled again after the benchmark
+  headers (upstream issue 3212).
+- `e87f2882`: test registration with non-type template parameters no longer
+  scales quadratically.
+- `73d546cd`: `REQUIRE` expands its arguments fewer times under GCC and
+  Clang.
+- `b710039a`: the decomposer operators are plain functions and no longer
+  hidden friends.
+- `f899467b`: streaming of reconstructed expressions is type-erased.
+- `8f0e70ca`: the retired `macos-14` runner is dropped from the macOS builds.
+- `08092139`: version 3.16.1, with its release notes.
+
+Each applied without a conflict in the sources. The amalgamated distribution
+under `extras/` did conflict, because it is generated; it was generated again
+from the sources of this repository with `generateAmalgamatedFiles.py`, which
+also brought it up to date with fork changes it had not yet picked up. No
+fork-owned file under `src/Progmasoft` needed a change.
+
 These are compatibility fixes, not a claim that every future upstream change
 is automatically incorporated. The existing Windows/macOS build and test
 workflows remain the verification gate for the fork.
diff --git a/docs/why-catch3.md b/docs/why-catch3.md
index 7fbeef44..8c900ac7 100644
--- a/docs/why-catch3.md
+++ b/docs/why-catch3.md
@@ -7,7 +7,7 @@ namespace, build-target, and licensing boundary.
 
 The name does **not** mean that this is an official Catch2 v3 release, a new
 upstream version, or a project endorsed by Catch2's maintainers. The current
-compatibility engine is based on Catch2's 3.16.0 development line. The project
+compatibility engine is based on Catch2's 3.16.1 development line. The project
 is still early-stage and does not yet replace or independently reimplement the
 Catch2 runner.
 
@@ -35,7 +35,7 @@ Catch2's `Catch` namespace, established headers, macros, command-line behavior,
 reporters, and coding style remain the compatibility surface. Progmasoft
 features should be added under `Progmasoft::Catch3` and must not require users
 to rename existing Catch2 tests. The first compatibility goal is source-level
-continuity with the included Catch2 3.16.0 base; this is not a promise that every
+continuity with the included Catch2 3.16.1 base; this is not a promise that every
 future Catch2 upstream change will be adopted unchanged or that all downstream
 projects have already been validated.
 
diff --git a/extras/catch_amalgamated.cpp b/extras/catch_amalgamated.cpp
index c6a8de36..230849f1 100644
--- a/extras/catch_amalgamated.cpp
+++ b/extras/catch_amalgamated.cpp
@@ -6,8 +6,8 @@
 
 // SPDX-License-Identifier: BSL-1.0
 
-//  Catch v3.16.0
-//  Generated: 2026-09-28 00:12:28.744397
+//  Catch v3.16.1
+//  Generated: 2026-10-11 02:09:25.622664
 //  ----------------------------------------------------------
 //  This file is an amalgamation of multiple different files.
 //  You probably shouldn't edit it directly.
@@ -1458,7 +1458,9 @@ namespace Catch {
                 int err = 0;
                 std::FILE* const file = openGuardFile( guardFilePath, err );
                 if ( file == nullptr ) {
+#if defined( _MSC_VER )
                     char msgBuffer[100] = {};
+#endif
                     std::string errMsg;
 #if defined( _MSC_VER )
                     if ( !strerror_s( msgBuffer, err ) ) {
@@ -1677,7 +1679,17 @@ namespace Catch {
             getCurrentMutableContext().setConfig(m_config.get());
 
             // Create reporter(s) so we can route listings through them
-            auto reporter = prepareReporters(m_config.get());
+            IEventListenerPtr reporter;
+            CATCH_TRY {
+                auto reporter_ = prepareReporters( m_config.get() );
+                swap( reporter, reporter_ );
+            }
+#if !defined( CATCH_CONFIG_DISABLE_EXCEPTIONS )
+            catch ( std::exception& ex ) {
+                Catch::cerr() << "Error when creating reporter: " << ex.what() << '\n' << std::flush;
+                return ReporterConstructionErrorExitCode;
+            }
+#endif
 
             auto const& invalidSpecs = m_config->testSpec().getInvalidSpecs();
             if ( !invalidSpecs.empty() ) {
@@ -2586,7 +2598,7 @@ namespace Catch {
     }
 
     Version const& libraryVersion() {
-        static Version version( 3, 16, 0, "", 0 );
+        static Version version( 3, 16, 1, "", 0 );
         return version;
     }
 
@@ -2922,7 +2934,7 @@ namespace Catch {
         }
     }
 
-    void AssertionHandler::handleUnexpectedInflightException() {
+    void AssertionHandler::handleUnexpectedInflightException() noexcept {
         m_resultCapture.handleUnexpectedInflightException( m_assertionInfo, Catch::translateActiveException(), m_reaction );
     }
 
@@ -4234,13 +4246,6 @@ namespace Catch {
 
 namespace Catch {
 
-    void ITransientExpression::streamReconstructedExpression(
-        std::ostream& os ) const {
-        // We can't make this function pure virtual to keep ITransientExpression
-        // constexpr, so we write error message instead
-        os << "Some class derived from ITransientExpression without overriding streamReconstructedExpression";
-    }
-
     void formatReconstructedExpression( std::ostream &os, std::string const& lhs, StringRef op, std::string const& rhs ) {
         if( lhs.size() + rhs.size() < 40 &&
                 lhs.find('\n') == std::string::npos &&
@@ -6056,6 +6061,7 @@ ReporterSpec::ReporterSpec(
 
 
 #include <cstdio>
+#include <list>
 #include <sstream>
 #include <tuple>
 #include <vector>
@@ -6065,7 +6071,10 @@ namespace Catch {
     // This class encapsulates the idea of a pool of ostringstreams that can be reused.
     struct StringStreams {
         std::vector<Detail::unique_ptr<std::ostringstream>> m_streams;
-        std::vector<std::size_t> m_unused;
+        // The library can be linked into ASan-instrumented clients without
+        // instrumenting Catch3 itself. A list avoids mixed-mode libc++ vector
+        // container annotations for the reusable-index pool.
+        std::list<std::size_t> m_unused;
         std::ostringstream m_referenceStream; // Used for copy state/ flags from
         Detail::Mutex m_mutex;
 
@@ -9530,12 +9539,20 @@ namespace Catch {
 
 
 
+
 #include <ostream>
 
 namespace Catch {
 
     AutomakeReporter::~AutomakeReporter() = default;
 
+    AutomakeReporter::AutomakeReporter( ReporterConfig&& _config ):
+        StreamingReporterBase( CATCH_MOVE( _config ) ) {
+        rejectSuperfluousConfigKeys( m_customOptions, {} );
+
+        m_preferences.shouldReportAllAssertionStarts = false;
+    }
+
     void AutomakeReporter::testCaseEnded(TestCaseStats const& _testCaseStats) {
         // Possible values to emit are PASS, XFAIL, SKIP, FAIL, XPASS and ERROR.
         m_stream << ":test-result: ";
@@ -9837,6 +9854,13 @@ private:
         }
 
         CompactReporter::~CompactReporter() = default;
+        CompactReporter::CompactReporter( ReporterConfig&& _config ):
+            StreamingReporterBase( CATCH_MOVE( _config ) ) {
+            rejectSuperfluousConfigKeys( m_customOptions, {} );
+
+            m_preferences.shouldReportAllAssertionStarts = false;
+        }
+
 
 } // end namespace Catch
 
@@ -10224,6 +10248,7 @@ ConsoleReporter::ConsoleReporter(ReporterConfig&& config):
             };
         }
     }())) {
+    rejectSuperfluousConfigKeys( m_customOptions, {} );
     m_preferences.shouldReportAllAssertionStarts = false;
 }
 
@@ -11037,6 +11062,18 @@ namespace Catch {
         printSummaryRow( stream, streamColour, "assertions"_sr, columns, 1 );
     }
 
+    void rejectSuperfluousConfigKeys(
+        std::map<std::string, std::string> const& options,
+        std::initializer_list<StringRef> knownKeys ) {
+        for ( auto const& option : options ) {
+            StringRef key( option.first );
+            CATCH_ENFORCE( std::find( knownKeys.begin(),
+                                      knownKeys.end(),
+                                      key ) != knownKeys.end(),
+                           "Unknown reporter argument: " << key );
+        }
+    }
+
 } // namespace Catch
 
 
@@ -11075,6 +11112,7 @@ namespace Catch {
 
     JsonReporter::JsonReporter( ReporterConfig&& config ):
         StreamingReporterBase{ CATCH_MOVE( config ) } {
+        rejectSuperfluousConfigKeys( m_customOptions, {} );
 
         m_preferences.shouldRedirectStdOut = true;
         // TBD: Do we want to report all assertions? XML reporter does
@@ -11480,11 +11518,13 @@ namespace Catch {
         :   CumulativeReporterBase( CATCH_MOVE(_config) ),
             xml( m_stream )
         {
+            rejectSuperfluousConfigKeys( m_customOptions, {} );
+
             m_preferences.shouldRedirectStdOut = true;
             m_preferences.shouldReportAllAssertions = false;
             m_preferences.shouldReportAllAssertionStarts = false;
             m_shouldStoreSuccesfulAssertions = false;
-        }
+    }
 
     std::string JunitReporter::getDescription() {
         return "Reports test results in an XML format that looks like Ant's junitreport target";
@@ -11947,6 +11987,16 @@ namespace Catch {
         }
     }
 
+    SonarQubeReporter::SonarQubeReporter( ReporterConfig&& config ):
+        CumulativeReporterBase( CATCH_MOVE( config ) ), xml( m_stream ) {
+        rejectSuperfluousConfigKeys( m_customOptions, {} );
+
+        m_preferences.shouldRedirectStdOut = true;
+        m_preferences.shouldReportAllAssertions = false;
+        m_preferences.shouldReportAllAssertionStarts = false;
+        m_shouldStoreSuccesfulAssertions = false;
+    }
+
     void SonarQubeReporter::testRunStarting(TestRunInfo const& testRunInfo) {
         CumulativeReporterBase::testRunStarting(testRunInfo);
 
@@ -12275,6 +12325,14 @@ namespace Catch {
 
     } // End anonymous namespace
 
+    TAPReporter::TAPReporter( ReporterConfig&& config ):
+        StreamingReporterBase( CATCH_MOVE( config ) ) {
+        rejectSuperfluousConfigKeys( m_customOptions, {} );
+
+        m_preferences.shouldReportAllAssertions = true;
+        m_preferences.shouldReportAllAssertionStarts = false;
+    }
+
     void TAPReporter::testRunStarting( TestRunInfo const& ) {
         if ( m_config->testSpec().hasFilters() ) {
             m_stream << "# filters: " << m_config->testSpec() << '\n';
@@ -12346,6 +12404,14 @@ namespace Catch {
     } // end anonymous namespace
 
 
+    TeamCityReporter::TeamCityReporter( ReporterConfig&& _config ):
+        StreamingReporterBase( CATCH_MOVE( _config ) ) {
+        rejectSuperfluousConfigKeys( m_customOptions, {} );
+
+        m_preferences.shouldRedirectStdOut = true;
+        m_preferences.shouldReportAllAssertionStarts = false;
+    }
+
     TeamCityReporter::~TeamCityReporter() = default;
 
     void TeamCityReporter::testRunStarting( TestRunInfo const& runInfo ) {
@@ -12492,6 +12558,8 @@ namespace Catch {
     :   StreamingReporterBase( CATCH_MOVE(_config) ),
         m_xml(m_stream)
     {
+        rejectSuperfluousConfigKeys( m_customOptions, {} );
+
         m_preferences.shouldRedirectStdOut = true;
         m_preferences.shouldReportAllAssertions = true;
         m_preferences.shouldReportAllAssertionStarts = false;
diff --git a/extras/catch_amalgamated.hpp b/extras/catch_amalgamated.hpp
index 29279da0..25207b85 100644
--- a/extras/catch_amalgamated.hpp
+++ b/extras/catch_amalgamated.hpp
@@ -6,8 +6,8 @@
 
 // SPDX-License-Identifier: BSL-1.0
 
-//  Catch v3.16.0
-//  Generated: 2026-09-28 00:12:28.337654
+//  Catch v3.16.1
+//  Generated: 2026-10-11 02:09:25.452537
 //  ----------------------------------------------------------
 //  This file is an amalgamation of multiple different files.
 //  You probably shouldn't edit it directly.
@@ -1520,7 +1520,7 @@ namespace Catch {
             *reinterpret_cast<char volatile*>(p) = *reinterpret_cast<char const volatile*>(p);
         }
         // TODO equivalent keep_memory()
-#if defined(_MSVC_VER)
+#if defined(_MSC_VER)
 #pragma optimize("", on)
 #endif
 
@@ -2513,6 +2513,9 @@ namespace Catch {
 // be null...
 #pragma GCC diagnostic ignored "-Waddress"
 #pragma GCC diagnostic ignored "-Wnonnull-compare"
+#elif defined(__clang__)
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wpointer-bool-conversion"
 #endif
 
         template<typename T>
@@ -2523,6 +2526,8 @@ namespace Catch {
 
 #if defined(__GNUC__) && !defined(__clang__)
 #pragma GCC diagnostic pop
+#elif defined(__clang__)
+#pragma clang diagnostic pop
 #endif
         auto get() -> std::ostream& { return *m_oss; }
     };
@@ -5130,6 +5135,7 @@ namespace Catch {
     constexpr int UnmatchedTestSpecExitCode = 3;
     constexpr int AllTestsSkippedExitCode = 4;
     constexpr int InvalidTestSpecExitCode = 5;
+    constexpr int ReporterConstructionErrorExitCode = 6;
     constexpr int TestFailureExitCode = 42;
 
     class Session : Detail::NonCopyable {
@@ -5531,28 +5537,27 @@ namespace Catch {
     struct always_false : std::false_type {};
 
     class ITransientExpression {
+        //! Type-erased streaming function for the derived expression
+        using StreamFn = void ( * )( void const*, std::ostream& );
+
+        StreamFn m_streamFn;
         bool m_isBinaryExpression;
         bool m_result;
 
-    protected:
-        ~ITransientExpression() = default;
-
     public:
         constexpr auto isBinaryExpression() const -> bool { return m_isBinaryExpression; }
         constexpr auto getResult() const -> bool { return m_result; }
-        //! This function **has** to be overridden by the derived class.
-        virtual void streamReconstructedExpression( std::ostream& os ) const;
 
-        constexpr ITransientExpression( bool isBinaryExpression, bool result )
-        :   m_isBinaryExpression( isBinaryExpression ),
-            m_result( result )
-        {}
-
-        constexpr ITransientExpression( ITransientExpression const& ) = default;
-        constexpr ITransientExpression& operator=( ITransientExpression const& ) = default;
+        constexpr ITransientExpression( StreamFn streamFn,
+                                        bool isBinaryExpression,
+                                        bool result ):
+            m_streamFn( streamFn ),
+            m_isBinaryExpression( isBinaryExpression ),
+            m_result( result ) {}
 
-        friend std::ostream& operator<<(std::ostream& out, ITransientExpression const& expr) {
-            expr.streamReconstructedExpression(out);
+        friend std::ostream& operator<<( std::ostream& out,
+                                         ITransientExpression const& expr ) {
+            expr.m_streamFn( &expr, out );
             return out;
         }
     };
@@ -5565,87 +5570,67 @@ namespace Catch {
         StringRef m_op;
         RhsT m_rhs;
 
-        void streamReconstructedExpression( std::ostream &os ) const override {
-            formatReconstructedExpression
-                    ( os, Catch::Detail::stringify( m_lhs ), m_op, Catch::Detail::stringify( m_rhs ) );
+        static void streamFn( void const* self, std::ostream& out ) {
+            auto const& expr = *static_cast<BinaryExpr const*>(
+                static_cast<ITransientExpression const*>( self ) );
+            formatReconstructedExpression(
+                out,
+                Catch::Detail::stringify( expr.m_lhs ),
+                expr.m_op,
+                Catch::Detail::stringify( expr.m_rhs ) );
         }
 
     public:
         constexpr BinaryExpr( bool comparisonResult, LhsT lhs, StringRef op, RhsT rhs )
-        :   ITransientExpression{ true, comparisonResult },
+        :   ITransientExpression{ &streamFn, true, comparisonResult },
             m_lhs( lhs ),
             m_op( op ),
             m_rhs( rhs )
         {}
+    };
 
-        template<typename T>
-        auto operator && ( T ) const -> BinaryExpr<LhsT, RhsT const&> const {
-            static_assert(always_false<T>::value,
-            "chained comparisons are not supported inside assertions, "
-            "wrap the expression inside parentheses, or decompose it");
-        }
-
-        template<typename T>
-        auto operator || ( T ) const -> BinaryExpr<LhsT, RhsT const&> const {
-            static_assert(always_false<T>::value,
-            "chained comparisons are not supported inside assertions, "
-            "wrap the expression inside parentheses, or decompose it");
-        }
-
-        template<typename T>
-        auto operator == ( T ) const -> BinaryExpr<LhsT, RhsT const&> const {
-            static_assert(always_false<T>::value,
-            "chained comparisons are not supported inside assertions, "
-            "wrap the expression inside parentheses, or decompose it");
-        }
-
-        template<typename T>
-        auto operator != ( T ) const -> BinaryExpr<LhsT, RhsT const&> const {
-            static_assert(always_false<T>::value,
-            "chained comparisons are not supported inside assertions, "
-            "wrap the expression inside parentheses, or decompose it");
-        }
-
-        template&