Allow easy retrieval of RNG seed by the users

This makes it so that they don't need parallel RNG seed passing
infrastructure for randomized data generation (e.g. inputs for
benchmarks).

6 files changed, 43 insertions, 2 deletions

diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index bd0b6d97..c76a96d5 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -137,6 +137,7 @@ set(INTERNAL_HEADERS
     ${SOURCES_DIR}/internal/catch_string_manip.hpp
     ${SOURCES_DIR}/internal/catch_stringref.hpp
     ${SOURCES_DIR}/catch_tag_alias.hpp
+    ${SOURCES_DIR}/catch_get_random_seed.hpp
     ${SOURCES_DIR}/catch_tag_alias_autoregistrar.hpp
     ${SOURCES_DIR}/internal/catch_tag_alias_registry.hpp
     ${SOURCES_DIR}/catch_test_case_info.hpp
@@ -230,6 +231,7 @@ set(IMPL_SOURCES
     ${SOURCES_DIR}/matchers/catch_matchers_predicate.cpp
     ${SOURCES_DIR}/matchers/internal/catch_matchers_impl.cpp
     ${SOURCES_DIR}/catch_tag_alias_autoregistrar.cpp
+    ${SOURCES_DIR}/catch_get_random_seed.cpp
     ${SOURCES_DIR}/internal/catch_decomposer.cpp
     ${SOURCES_DIR}/internal/catch_errno_guard.cpp
     ${SOURCES_DIR}/internal/catch_lazy_expr.cpp
diff --git a/src/catch2/catch_all.hpp b/src/catch2/catch_all.hpp
index 5c715e35..94f55223 100644
--- a/src/catch2/catch_all.hpp
+++ b/src/catch2/catch_all.hpp
@@ -27,6 +27,7 @@
 #include <catch2/catch_assertion_info.hpp>
 #include <catch2/catch_assertion_result.hpp>
 #include <catch2/catch_config.hpp>
+#include <catch2/catch_get_random_seed.hpp>
 #include <catch2/catch_message.hpp>
 #include <catch2/catch_section_info.hpp>
 #include <catch2/catch_session.hpp>
diff --git a/src/catch2/catch_get_random_seed.cpp b/src/catch2/catch_get_random_seed.cpp
new file mode 100644
index 00000000..12a5b6d8
--- /dev/null
+++ b/src/catch2/catch_get_random_seed.cpp
@@ -0,0 +1,18 @@
+
+//              Copyright Catch2 Authors
+// Distributed under the Boost Software License, Version 1.0.
+//   (See accompanying file LICENSE_1_0.txt or copy at
+//        https://www.boost.org/LICENSE_1_0.txt)
+
+// SPDX-License-Identifier: BSL-1.0
+
+#include <catch2/catch_get_random_seed.hpp>
+
+#include <catch2/internal/catch_context.hpp>
+#include <catch2/catch_config.hpp>
+
+namespace Catch {
+    std::uint32_t getSeed() {
+        return getCurrentContext().getConfig()->rngSeed();
+    }
+}
diff --git a/src/catch2/catch_get_random_seed.hpp b/src/catch2/catch_get_random_seed.hpp
new file mode 100644
index 00000000..6df3c3a0
--- /dev/null
+++ b/src/catch2/catch_get_random_seed.hpp
@@ -0,0 +1,18 @@
+
+//              Copyright Catch2 Authors
+// Distributed under the Boost Software License, Version 1.0.
+//   (See accompanying file LICENSE_1_0.txt or copy at
+//        https://www.boost.org/LICENSE_1_0.txt)
+
+// SPDX-License-Identifier: BSL-1.0
+#ifndef CATCH_GET_RANDOM_SEED_HPP_INCLUDED
+#define CATCH_GET_RANDOM_SEED_HPP_INCLUDED
+
+#include <cstdint>
+
+namespace Catch {
+    //! Returns Catch2's current RNG seed.
+    std::uint32_t getSeed();
+}
+
+#endif // CATCH_GET_RANDOM_SEED_HPP_INCLUDED
diff --git a/src/catch2/reporters/catch_reporter_compact.cpp b/src/catch2/reporters/catch_reporter_compact.cpp
index 3f036ec5..a09f0483 100644
--- a/src/catch2/reporters/catch_reporter_compact.cpp
+++ b/src/catch2/reporters/catch_reporter_compact.cpp
@@ -7,6 +7,7 @@
 // SPDX-License-Identifier: BSL-1.0
 #include <catch2/reporters/catch_reporter_compact.hpp>
 
+#include <catch2/catch_get_random_seed.hpp>
 #include <catch2/catch_test_spec.hpp>
 #include <catch2/reporters/catch_reporter_helpers.hpp>
 #include <catch2/interfaces/catch_interfaces_config.hpp>
@@ -261,7 +262,7 @@ private:
                          << serializeFilters( m_config->getTestsOrTags() )
                          << '\n';
             }
-            m_stream << "RNG seed: " << m_config->rngSeed() << '\n';
+            m_stream << "RNG seed: " << getSeed() << '\n';
         }
 
         void CompactReporter::assertionEnded( AssertionStats const& _assertionStats ) {
diff --git a/src/catch2/reporters/catch_reporter_console.cpp b/src/catch2/reporters/catch_reporter_console.cpp
index bb755ed7..88d43b53 100644
--- a/src/catch2/reporters/catch_reporter_console.cpp
+++ b/src/catch2/reporters/catch_reporter_console.cpp
@@ -19,6 +19,7 @@
 #include <catch2/internal/catch_console_width.hpp>
 #include <catch2/reporters/catch_reporter_helpers.hpp>
 #include <catch2/internal/catch_move_and_forward.hpp>
+#include <catch2/catch_get_random_seed.hpp>
 
 #include <cstdio>
 
@@ -500,7 +501,7 @@ void ConsoleReporter::testRunStarting(TestRunInfo const& _testInfo) {
         m_stream << m_colour->guardColour( Colour::BrightYellow ) << "Filters: "
                  << serializeFilters( m_config->getTestsOrTags() ) << '\n';
     }
-    m_stream << "Randomness seeded to: " << m_config->rngSeed() << '\n';
+    m_stream << "Randomness seeded to: " << getSeed() << '\n';
 }
 
 void ConsoleReporter::lazyPrint() {