Simplify testing and feature testing infrastructure

Author: hkaiser

cmake/HPX_AddConfigTest.cmake

@@ -687,6 +687,14 @@ function(hpx_check_for_cxx26_experimental_scope)
   )
 endfunction()
 
+function(hpx_check_for_cxx26_contracts)
+  add_hpx_config_test(
+    HPX_WITH_CXX26_CONTRACTS
+    SOURCE cmake/tests/cxx26_contracts.cpp
+    FILE ${ARGN}
+  )
+endfunction()
+
 # ##############################################################################
 function(hpx_check_for_cxx_lambda_capture_decltype)
   add_hpx_config_test(

cmake/HPX_PerformCxxFeatureTests.cmake

@@ -173,6 +173,8 @@ function(hpx_perform_cxx_feature_tests)
     DEFINITIONS HPX_HAVE_CXX26_EXPERIMENTAL_SCOPE
   )
 
+  hpx_check_for_cxx26_contracts(DEFINITIONS HPX_HAVE_CXX26_CONTRACTS)
+
   hpx_check_for_cxx_lambda_capture_decltype(
     DEFINITIONS HPX_HAVE_CXX_LAMBDA_CAPTURE_DECLTYPE
   )

cmake/tests/cxx26_contracts.cpp

@@ -0,0 +1,20 @@
+//  Copyright (c) 2025 Hartmut Kaiser
+//
+//  SPDX-License-Identifier: BSL-1.0
+//  Distributed under the Boost Software License, Version 1.0. (See accompanying
+//  file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+// test for availability of C++26 contracts
+
+#if !defined(__cpp_contracts)
+#error "__cpp_contracts not defined, assume contracts are not supported"
+#endif
+
+#include <contracts>
+
+// Test actual contract syntax support (for experimental implementations)
+int main() pre(true) post(r : r == 0)
+{
+    contract_assert(true);
+    return 0;
+}

libs/core/contracts/CMakeLists.txt

@@ -7,21 +7,27 @@
 
 list(APPEND CMAKE_MODULE_PATH "${CMAKE_CURRENT_SOURCE_DIR}/cmake")
 
+if(HPX_WITH_CXX26_CONTRACTS)
+  # Map existing HPX_ASSERT to contract_assert
+  hpx_option(
+    HPX_CONTRACTS_WITH_ASSERTS_AS_CONTRACT_ASSERTS BOOL
+    "Map existing HPX_ASERT to contract_assert. (default: ON)" ON ADVANCED
+    CATEGORY "Modules"
+    MODULE CONTRACTS
+  )
+
+  if(HPX_CONTRACTS_WITH_ASSERTS_AS_CONTRACT_ASSERTS)
+    hpx_add_config_define_namespace(
+      DEFINE HPX_CONTRACTS_HAVE_ASSERTS_AS_CONTRACT_ASSERTS NAMESPACE CONTRACTS
+    )
+  endif()
+endif()
+
 # Default location is $HPX_ROOT/libs/contracts/include
 set(contracts_headers hpx/contracts.hpp hpx/modules/contracts.hpp)
 
-# Default location is $HPX_ROOT/libs/contracts/include_compatibility
-# cmake-format: off
-set(contracts_compat_headers
-    # Add any legacy header mappings here if needed in the future
-    # hpx/old_contracts.hpp => hpx/contracts.hpp
-)
-# cmake-format: on
-
 # Default location is $HPX_ROOT/libs/contracts/src
-set(contracts_sources # Add source files here when implementation is added
-    # contracts.cpp
-)
+set(contracts_sources)
 
 include(HPX_AddModule)
 add_hpx_module(

libs/core/contracts/docs/index.rst

@@ -23,34 +23,31 @@ automatically adapt their behavior based on compiler capabilities:
 
 * When C++26 native contracts are available (``__cpp_contracts`` defined), 
   they map to standard contract syntax
-* When contracts are not available but ``HPX_WITH_CONTRACTS=ON``, preconditions 
-  and postconditions become no-ops while contract assertions fall back to 
-  :c:macro:`HPX_ASSERT` for compatibility
-* When ``HPX_WITH_CONTRACTS=OFF``, preconditions and postconditions become 
+* When ``HPX_WITH_CX26_CONTRACTS=OFF``, preconditions and postconditions become 
   no-ops while contract assertions remain available as enhanced assertions
 
 Configuration
 =============
 
 Enable contracts in CMake::
 
-    cmake -DHPX_WITH_CONTRACTS=ON -DCMAKE_CXX_STANDARD=26
+    cmake -DHPX_WITH_CXX26_CONTRACTS=ON -DCMAKE_CXX_STANDARD=26
 
 Enable contract-enhanced assertions (optional)::
 
-    cmake -DHPX_WITH_CONTRACTS=ON -DHPX_WITH_ASSERTS_AS_CONTRACT_ASSERTS=ON
+    cmake -DHPX_WITH_CXX26_CONTRACTS=ON -DHPX_CONTRACTS_WITH_ASSERTS_AS_CONTRACT_ASSERTS=ON
 
 Contract assertions work even when contracts are disabled::
 
-    cmake -DHPX_WITH_CONTRACTS=OFF  # HPX_CONTRACT_ASSERT still maps to HPX_ASSERT
+    cmake -DHPX_WITH_CXX26_CONTRACTS=OFF  # HPX_CONTRACT_ASSERT still maps to HPX_ASSERT
 
 Advanced Features
 =================
 
 Contract-Enhanced Assertions
 ----------------------------
 
-When ``HPX_WITH_ASSERTS_AS_CONTRACT_ASSERTS=ON`` is enabled, regular 
+When ``HPX_CONTRACTS_WITH_ASSERTS_AS_CONTRACT_ASSERTS=ON`` is enabled, regular 
 :c:macro:`HPX_ASSERT` calls are automatically upgraded to use contract 
 assertions in C++26 mode::
 
@@ -63,17 +60,16 @@ assertions in C++26 mode::
 .. warning::
    Enhanced assertions only provide benefits when native C++26 contracts are 
    supported by the compiler. Without native contract support, 
-   ``HPX_ASSERT`` → ``HPX_CONTRACT_ASSERT`` → ``HPX_ASSERT`` (no enhancement).
+   ``HPX_ASSERT`` -> ``HPX_CONTRACT_ASSERT`` -> ``HPX_ASSERT`` (no enhancement).
    CMake will issue a warning if you enable this option without native contract support.
 
 This provides enhanced contract semantics throughout your existing codebase 
 without requiring changes to assertion code. The transformation occurs in the
 contracts module (``contracts.hpp``) where the ``HPX_ASSERT`` macro is 
 overridden to use ``HPX_CONTRACT_ASSERT`` when ``HPX_WITH_ASSERTS_AS_CONTRACT_ASSERTS=ON``:
 
-* ``HPX_WITH_CONTRACTS=ON`` - Contracts module is enabled
-* ``HPX_WITH_ASSERTS_AS_CONTRACT_ASSERTS=ON`` - Assertion enhancement is enabled  
-* ``HPX_HAVE_NATIVE_CONTRACTS=ON`` - C++26 native contracts are available (from config test)
+* ``HPX_WITH_CXX26_CONTRACTS=ON`` - Contracts module is enabled
+* ``HPX_CONTRACTS_WITH_ASSERTS_AS_CONTRACT_ASSERTS=ON`` - Assertion enhancement is enabled  
 
 The implementation works by redefining ``HPX_ASSERT`` in ``contracts.hpp`` to 
 use ``HPX_CONTRACT_ASSERT``, which automatically adapts to the current contract 
@@ -155,4 +151,4 @@ detection. Tests are organized into three categories:
 The test suite automatically detects compiler capabilities at configure time 
 and builds only the appropriate tests for the current configuration.
 
-See the :ref:`API reference <modules_contracts_api>` of the module for more details.
+See the :ref:`API reference <modules_contracts_api>` of the module for more details.

libs/core/contracts/include/hpx/modules/contracts.hpp

@@ -29,30 +29,24 @@
 
 // Contract implementation: automatically selects native C++26 contracts
 // or provides appropriate fallback behavior based on compiler capabilities
-#ifdef HPX_HAVE_CONTRACTS
-#if HPX_HAVE_NATIVE_CONTRACTS
+#if defined(HPX_HAVE_CXX26_CONTRACTS)
+
 // Native C++26 contracts mode
 #define HPX_PRE(x) pre(x)
 #define HPX_CONTRACT_ASSERT(x) contract_assert(x)
 #define HPX_POST(x) post(x)
+
+#if defined(HPX_CONTRACTS_HAVE_ASSERTS_AS_CONTRACT_ASSERTS)
+// Override HPX_ASSERT to use contract assertions
+#define HPX_ASSERT(x) contract_assert(x)
+#endif
+
 #else
+
 // Fallback mode: PRE/POST become no-ops for forward compatibility,
 // CONTRACT_ASSERT maps to HPX_ASSERT for runtime validation
-#pragma message(                                                               \
-    "HPX Contracts: Using assertion fallback mode. "                           \
-    "HPX_PRE/HPX_POST are no-ops, HPX_CONTRACT_ASSERT maps to HPX_ASSERT.")
 #define HPX_PRE(x)
 #define HPX_CONTRACT_ASSERT(x) HPX_ASSERT((x))
 #define HPX_POST(x)
-#endif
-#else
-// Contracts disabled: PRE/POST are no-ops, CONTRACT_ASSERT remains available
-#define HPX_PRE(x)
-#define HPX_CONTRACT_ASSERT(x) HPX_ASSERT((x))
-#define HPX_POST(x)
-#endif
 
-#ifdef HPX_HAVE_ASSERTS_AS_CONTRACT_ASSERTS
-// Override HPX_ASSERT to use contract assertions
-#define HPX_ASSERT(x) HPX_CONTRACT_ASSERT(x)
 #endif

libs/core/contracts/tests/performance/CMakeLists.txt

@@ -5,12 +5,3 @@
 # SPDX-License-Identifier: BSL-1.0
 # Distributed under the Boost Software License, Version 1.0. (See accompanying
 # file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
-
-# Currently no performance tests for contracts module Performance tests will be
-# added to measure contract overhead
-
-if(HPX_WITH_TESTS)
-  # Future: Add contract performance benchmarks here These would measure the
-  # overhead of contract checking add_hpx_unit_test("contracts"
-  # contract_performance_test SOURCES contract_performance_test.cpp )
-endif()

libs/core/contracts/tests/regressions/CMakeLists.txt

@@ -5,12 +5,3 @@
 # SPDX-License-Identifier: BSL-1.0
 # Distributed under the Boost Software License, Version 1.0. (See accompanying
 # file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
-
-# Currently no regression tests for contracts module Regression tests will be
-# added as the contract system matures
-
-if(HPX_WITH_TESTS)
-  # Future: Add contract regression tests here These would test specific bug
-  # fixes and edge cases add_hpx_unit_test("contracts" contract_regression_test1
-  # SOURCES contract_regression_test1.cpp )
-endif()