Improve find_package(highs) for HiPO

.github/workflows/build-nuget-package.yml

@@ -48,7 +48,7 @@ jobs:
 
   # Build macos arm64
   build_macos_arm:
-    runs-on: macos-14  # macos-14 is arm64
+    runs-on: macos-15  # macos-15 is arm64
     steps:
       - uses: actions/checkout@v6
       - name: Build HiGHS

.github/workflows/build-python-package.yml

@@ -161,7 +161,7 @@ jobs:
           python3 -m pytest ./highspy
 
   build_wheel_macos_arm:
-    runs-on: macos-14  # macos-14 is arm64
+    runs-on: macos-15  # macos-15 is arm64
     strategy:
       matrix:
         python: [3.11]

.github/workflows/build-wheels-push.yml

@@ -45,7 +45,7 @@ jobs:
           - [ubuntu-24.04, musllinux_i686]
           - [ubuntu-24.04-arm, musllinux_aarch64]
           - [macos-15-intel, macosx_x86_64]
-          - [macos-14, macosx_arm64]
+          - [macos-15, macosx_arm64]
           - [windows-2022, win_amd64]
           - [windows-2022, win32]
           - [windows-11-arm, win_arm64]
@@ -95,7 +95,7 @@ jobs:
           - [ubuntu-24.04, musllinux_i686]
           - [ubuntu-24.04-arm, musllinux_aarch64]
           - [macos-15-intel, macosx_x86_64]
-          - [macos-14, macosx_arm64]
+          - [macos-15, macosx_arm64]
           - [windows-2022, win_amd64]
           - [windows-2022, win32]
           - [windows-11-arm, win_arm64]

.github/workflows/julia-tests.yml

@@ -55,7 +55,7 @@ jobs:
             os: 'ubuntu-latest'
             arch: x64
           - triplet: 'aarch64-apple-darwin'
-            os: 'macos-14'
+            os: 'macos-15'
             arch: aarch64
           - triplet: 'x86_64-w64-mingw32-cxx11'
             os: 'windows-latest'

.github/workflows/test-nuget-macos.yml

@@ -58,7 +58,7 @@ jobs:
 
 
   build_macos_arm:
-    runs-on: macos-14  # macos-14 is arm64
+    runs-on: macos-15  # macos-15 is arm64
     steps:
       - uses: actions/checkout@v6
       - name: Build HiGHS

.github/workflows/test-nuget-package.yml

@@ -57,7 +57,7 @@ jobs:
           dotnet run
 
   build_macos_arm:
-    runs-on: macos-14  # macos-14 is arm64
+    runs-on: macos-15  # macos-15 is arm64
     steps:
       - uses: actions/checkout@v6
       - name: Build HiGHS

cmake/FindHipoDeps.cmake

@@ -80,7 +80,8 @@ macro(highs_export_blas_state)
             HIGHS_BLAS_COMPILE_DEFINITION
             HIGHS_BLAS_VENDOR
             HIGHS_BLAS_VERSION
-            HIGHS_BLAS_LICENSE)
+            HIGHS_BLAS_LICENSE
+            BLA_VENDOR)
         if(DEFINED ${_highs_blas_var})
             set(${_highs_blas_var} "${${_highs_blas_var}}" PARENT_SCOPE)
         else()
@@ -546,7 +547,6 @@ function(highs_configure_blas)
 
         set(OpenBLAS_FOUND TRUE)
         set(HIGHS_BLAS_TARGET ${_openblas_target})
-        set(HIGHS_BLAS_INCLUDE_DIRS "${CMAKE_BINARY_DIR}/_deps/openblas-src/include")
         highs_configure_blas_metadata()
 
         set(HIGHS_BLAS_CONFIGURED TRUE)
@@ -736,14 +736,51 @@ function(highs_link_blas target_name)
         message(FATAL_ERROR "BLAS not found for ${target_name}.")
     endif()
 
-    if(BUILD_OPENBLAS AND NOT TARGET ${HIGHS_BLAS_TARGET})
+    if(BUILD_OPENBLAS AND NOT TARGET "${HIGHS_BLAS_TARGET}")
         message(FATAL_ERROR "OpenBLAS target not found for ${target_name}.")
     endif()
 
-    target_link_libraries(${target_name} PUBLIC ${HIGHS_BLAS_TARGET})
+    # PRIVATE: a shared highs_extras is loaded at run time, so a consumer never
+    # links to its BLAS, and a static one still passes BLAS on for linking only
+    target_link_libraries(${target_name} PRIVATE ${HIGHS_BLAS_TARGET})
 
     if(HIGHS_BLAS_INCLUDE_DIRS)
-        target_include_directories(${target_name} PUBLIC
-            $<BUILD_INTERFACE:${HIGHS_BLAS_INCLUDE_DIRS}>)
+        target_include_directories(${target_name} PRIVATE ${HIGHS_BLAS_INCLUDE_DIRS})
     endif()
-endfunction()
+endfunction()
+
+# Lets highs-config.cmake make available the BLAS that a static highs_extras
+# passes on to the consumer's link. Nothing is needed for a shared highs_extras,
+# a library path, or highs_openblas, which HiGHS exports.
+function(highs_export_blas_dependency)
+    set(_dependency "")
+    if(NOT BUILD_SHARED_EXTRAS_LIB)
+        if(HIGHS_BLAS_TARGET STREQUAL "BLAS::BLAS")
+            set(_dependency "if(NOT BLA_VENDOR)\n  set(BLA_VENDOR \"${BLA_VENDOR}\")\nendif()\n")
+            # FindBLAS takes a library given by the user without searching for
+            # one, but only from the cache: it clears the normal variable
+            if(DEFINED CACHE{BLAS_LIBRARIES})
+                string(APPEND _dependency
+                    "set(BLAS_LIBRARIES \"${BLAS_LIBRARIES}\" CACHE STRING \"BLAS library HiGHS was built with\")\n")
+            endif()
+            string(APPEND _dependency "find_dependency(BLAS)\n")
+        elseif(HIGHS_BLAS_TARGET STREQUAL "OpenBLAS::OpenBLAS")
+            set(_dependency "find_dependency(OpenBLAS CONFIG HINTS \"${OpenBLAS_DIR}\")\n")
+        elseif(BUILD_OPENBLAS AND NOT HIGHS_BLAS_TARGET STREQUAL "highs_openblas")
+            # Built by FetchContent: installed with its own CMake package next to
+            # the one for HiGHS, whereas a build tree gets it from the export below
+            string(CONCAT _dependency
+                "if(EXISTS \"\${CMAKE_CURRENT_LIST_DIR}/../OpenBLAS/OpenBLASConfig.cmake\")\n"
+                "  find_dependency(OpenBLAS CONFIG NO_DEFAULT_PATH PATHS \"\${CMAKE_CURRENT_LIST_DIR}/../OpenBLAS\")\n"
+                "endif()\n")
+            export(TARGETS ${HIGHS_BLAS_TARGET}
+                APPEND FILE "${HIGHS_BINARY_DIR}/highs-targets.cmake")
+        endif()
+    endif()
+
+    set(_file "${HIGHS_BINARY_DIR}/highs-blas-dependency.cmake")
+    file(WRITE "${_file}" "${_dependency}")
+    install(FILES "${_file}"
+        DESTINATION "${CMAKE_INSTALL_LIBDIR}/cmake/highs"
+        COMPONENT Devel)
+endfunction()

cmake/cpp-highs.cmake

@@ -87,23 +87,6 @@ if (CUPDLP_GPU AND NOT HIGHS_GPU_LIB AND NOT HIPDLP_HIP)
   endif()
 endif()
 
-if (BUILD_OPENBLAS AND TARGET ${HIGHS_BLAS_TARGET})
-  install(TARGETS ${HIGHS_BLAS_TARGET}
-      EXPORT ${lower}-targets
-      INCLUDES DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}
-      ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR}
-      LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}
-      RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR}
-      COMPONENT libs)
-
-  if (NOT HIGHS_COVERAGE)
-    # Add library targets to the build-tree export set
-    export(TARGETS ${HIGHS_BLAS_TARGET}
-      NAMESPACE ${PROJECT_NAMESPACE}::
-      APPEND FILE "${HIGHS_BINARY_DIR}/highs-targets.cmake")
-  endif()
-endif()
-
 if (NOT HIGHS_COVERAGE)
   install(EXPORT ${lower}-targets
     NAMESPACE ${PROJECT_NAMESPACE}::

cmake/highs-config.cmake.in

@@ -7,16 +7,14 @@ set(@PACKAGE_PREFIX@_VERSION @PROJECT_VERSION@)
 include(CMakeFindDependencyMacro)
 find_dependency(Threads)
 
-# Only look for BLAS if highs was built with it
-set(_HIGHS_HAVE_BLAS @HIPO@)
+# Let users know about optional features
+set(HIGHS_HAVE_BLAS @HIPO@)
 
-if(_HIGHS_HAVE_BLAS)
-    find_dependency(BLAS)
+# Written by a build with HiPO, for the BLAS it was built with
+if(HIGHS_HAVE_BLAS)
+  include("${CMAKE_CURRENT_LIST_DIR}/highs-blas-dependency.cmake" OPTIONAL)
 endif()
 
-# Let users know about optional features
-set(HIGHS_HAVE_BLAS ${_HIGHS_HAVE_BLAS})
-
 @CONF_ZLIB@
 
 include("${CMAKE_CURRENT_LIST_DIR}/highs-targets.cmake")

extern/CMakeLists.txt

@@ -117,4 +117,7 @@ install(TARGETS highs_extras
 if(DEFINED HIGHS_BINARY_DIR)
   export(TARGETS highs_extras
     APPEND FILE "${HIGHS_BINARY_DIR}/highs-targets.cmake")
+  if(HIPO)
+    highs_export_blas_dependency()
+  endif()
 endif()