Fixing STD_EXEC and algorithm tests

Signed-off-by: Hartmut Kaiser <hartmut.kaiser@gmail.com>

Author: hkaiser

cmake/HPX_SetupTarget.cmake

@@ -190,8 +190,8 @@ function(hpx_setup_target target)
         )
       endif()
     endif()
-  elseif(HPX_WITH_CXX_MODULES AND ${target}_SCAN_FOR_MODULES)
-    set(${target}_SCAN_FOR_MODULES OFF)
+  elseif(HPX_WITH_CXX_MODULES AND target_SCAN_FOR_MODULES)
+    set(target_SCAN_FOR_MODULES OFF)
   endif()
 
   if(("${_type}" STREQUAL "EXECUTABLE") AND MINGW)
@@ -231,21 +231,29 @@ function(hpx_setup_target target)
 
   if(HPX_WITH_CXX_MODULES AND target_SCAN_FOR_MODULES)
     hpx_debug("setup_target.${target} SCAN_FOR_MODULES: ON")
+
     hpx_configure_module_consumer(${target} hpx_core_module_if)
     if(TARGET hpx_full_module_if)
       hpx_configure_module_consumer(${target} hpx_full_module_if)
     endif()
   else()
     hpx_debug("setup_target.${target} SCAN_FOR_MODULES: OFF")
 
-    # If modules are enabled, Clang emits DWARF v5, which requires using lld
-    # instead of ld.
-    if(HPX_WITH_CXX_MODULES AND (CMAKE_CXX_COMPILER_ID MATCHES "Clang"
-                                 OR CMAKE_CXX_COMPILER_ID MATCHES "AppleClang")
-    )
-      get_target_property(_type ${target} TYPE)
-      if((_type STREQUAL "SHARED_LIBRARY") OR (_type STREQUAL "EXECUTABLE"))
-        target_link_options(${target} PRIVATE "-fuse-ld=lld")
+    if(HPX_WITH_CXX_MODULES)
+      # explicitly disable C++ modules
+      target_compile_definitions(
+        ${target} PRIVATE HPX_HAVE_FORCE_NO_CXX_MODULES
+      )
+
+      # If modules are enabled, Clang emits DWARF v5, which requires using lld
+      # instead of ld.
+      if(CMAKE_CXX_COMPILER_ID MATCHES "Clang" OR CMAKE_CXX_COMPILER_ID MATCHES
+                                                  "AppleClang"
+      )
+        get_target_property(_type ${target} TYPE)
+        if((_type STREQUAL "SHARED_LIBRARY") OR (_type STREQUAL "EXECUTABLE"))
+          target_link_options(${target} PRIVATE "-fuse-ld=lld")
+        endif()
       endif()
     endif()
 

cmake/templates/global_module_header_modules.hpp.in

@@ -11,8 +11,17 @@
 
 #include <hpx/config/defines.hpp>
 
+// The compilation will fall back to using the HPX headers (instead of the
+// generated C++ module interface files) if any of the following is true:
+//
+// - C++ modules are not enabled
+// - Otherwise:
+//   - The HPX @libname@ library is being compiled
+//   - The module interface file is being compiled
+//   - The current translation unit is not forcing to disable using C++ modules
+//
 #if !defined(HPX_HAVE_CXX_MODULES) || defined(HPX_@libname_upper@_EXPORTS) ||             \
-    defined(HPX_COMPILE_BMI)
+    defined(HPX_COMPILE_BMI) || defined(HPX_HAVE_FORCE_NO_CXX_MODULES)
 @module_headers@
 #else
 

libs/core/algorithms/CMakeLists.txt

@@ -266,7 +266,8 @@ add_hpx_module(
   GLOBAL_HEADER_MODULE_GEN ON
   HEADERS ${algorithms_headers}
   COMPAT_HEADERS ${algorithms_compat_headers}
-  ADD_TO_GLOBAL_HEADER "hpx/parallel/util/detail/handle_remote_exceptions.hpp"
+  ADD_TO_GLOBAL_HEADER "hpx/parallel/util/detail/chunk_size_iterator.hpp"
+                       "hpx/parallel/util/detail/handle_remote_exceptions.hpp"
   SOURCES ${algorithms_sources}
   MODULE_DEPENDENCIES
     hpx_async_combinators

libs/core/algorithms/include/hpx/parallel/unseq/simd_helpers.hpp

@@ -1,5 +1,5 @@
 //  Copyright (c) 2022 A Kishore Kumar
-//  Copyright (c) 2023 Hartmut Kaiser
+//  Copyright (c) 2023-2026 Hartmut Kaiser
 //
 //  SPDX-License-Identifier: BSL-1.0
 //  Distributed under the Boost Software License, Version 1.0. (See accompanying
@@ -25,7 +25,7 @@ namespace hpx::parallel::util {
 
     // Compiler and Hardware should also support vector operations for IterDiff,
     // else we see slower performance when compared to sequential version
-    template <typename Iter, typename IterDiff, typename F>
+    HPX_CXX_CORE_EXPORT template <typename Iter, typename IterDiff, typename F>
     Iter unseq_first_n(Iter const first, IterDiff const n, F&& f) noexcept
     {
         // OMP loops can not have ++Iter, only integral types are allowed Hence
@@ -54,7 +54,7 @@ namespace hpx::parallel::util {
         IterDiff i = 0;
         constexpr std::int32_t num_blocks =
             HPX_LANE_SIZE / sizeof(std::int32_t);
-        alignas(HPX_LANE_SIZE) std::int32_t simd_lane[num_blocks] = {0};
+        alignas(HPX_LANE_SIZE) std::int32_t simd_lane[num_blocks] = {};
 
         while (i <= n - num_blocks)
         {
@@ -98,7 +98,8 @@ namespace hpx::parallel::util {
 #endif    // HPX_EARLYEXIT_PRESENT
     }
 
-    template <typename Iter1, typename Iter2, typename IterDiff, typename F>
+    HPX_CXX_CORE_EXPORT template <typename Iter1, typename Iter2,
+        typename IterDiff, typename F>
     std::pair<Iter1, Iter2> unseq2_first_n(Iter1 const first1,
         Iter2 const first2, IterDiff const n, F&& f) noexcept
     {
@@ -118,7 +119,7 @@ namespace hpx::parallel::util {
 
         constexpr std::int32_t num_blocks =
             HPX_LANE_SIZE / sizeof(std::int32_t);
-        alignas(HPX_LANE_SIZE) std::int32_t simd_lane[num_blocks] = {0};
+        alignas(HPX_LANE_SIZE) std::int32_t simd_lane[num_blocks] = {};
 
         IterDiff outer_loop_ind = 0;
         while (outer_loop_ind <= n - num_blocks)

libs/core/algorithms/tests/performance/transform_reduce_scaling.cpp

@@ -1,12 +1,13 @@
 //  Copyright (c) 2014 Grant Mercer
-//  Copyright (c) 2020-2025 Hartmut Kaiser
+//  Copyright (c) 2020-2026 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)
 
 #include <hpx/chrono.hpp>
 #include <hpx/init.hpp>
+#include <hpx/modules/type_support.hpp>
 #include <hpx/numeric.hpp>
 
 #include "worker_timed.hpp"

libs/core/algorithms/tests/regressions/ranges_facilities.cpp

@@ -5,8 +5,8 @@
 //  file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
 
 #include <hpx/iterator_support/tests/iter_sent.hpp>
+#include <hpx/modules/algorithms.hpp>
 #include <hpx/modules/testing.hpp>
-#include <hpx/parallel/util/ranges_facilities.hpp>
 
 #include <cstdint>
 #include <vector>

libs/core/algorithms/tests/unit/algorithms/detail/chunk_size_idx_iterator.cpp

@@ -9,9 +9,9 @@
 //  file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
 
 #include <hpx/iterator_support/tests/iterator_tests.hpp>
+#include <hpx/modules/algorithms.hpp>
 #include <hpx/modules/datastructures.hpp>
 #include <hpx/modules/testing.hpp>
-#include <hpx/parallel/util/detail/chunk_size_iterator.hpp>
 
 #include <algorithm>
 #include <cstddef>

libs/core/algorithms/tests/unit/algorithms/detail/chunk_size_iterator.cpp

@@ -9,9 +9,9 @@
 //  file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
 
 #include <hpx/iterator_support/tests/iterator_tests.hpp>
+#include <hpx/modules/algorithms.hpp>
 #include <hpx/modules/datastructures.hpp>
 #include <hpx/modules/testing.hpp>
-#include <hpx/parallel/util/detail/chunk_size_iterator.hpp>
 
 #include <algorithm>
 #include <cstddef>

libs/core/algorithms/tests/unit/algorithms/uninitialized_relocate.cpp

@@ -8,6 +8,7 @@
 #include <hpx/modules/algorithms.hpp>
 #include <hpx/modules/executors.hpp>
 #include <hpx/modules/testing.hpp>
+#include <hpx/modules/type_support.hpp>
 
 #include <atomic>
 #include <random>

libs/core/algorithms/tests/unit/algorithms/uninitialized_relocate_backward.cpp

@@ -8,6 +8,7 @@
 #include <hpx/modules/algorithms.hpp>
 #include <hpx/modules/executors.hpp>
 #include <hpx/modules/testing.hpp>
+#include <hpx/modules/type_support.hpp>
 
 #include <atomic>
 #include <random>