fix cmake windows blas lookup

Author: galabovaa

HiGHS.sln

@@ -0,0 +1,24 @@
+Microsoft Visual Studio Solution File, Format Version 12.00
+# Visual Studio Version 17
+VisualStudioVersion = 17.5.2.0
+MinimumVisualStudioVersion = 10.0.40219.1
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Highs", "nuget\Highs.csproj", "{906CCF22-9F98-849C-F4C4-760DF67E239A}"
+EndProject
+Global
+	GlobalSection(SolutionConfigurationPlatforms) = preSolution
+		Debug|Any CPU = Debug|Any CPU
+		Release|Any CPU = Release|Any CPU
+	EndGlobalSection
+	GlobalSection(ProjectConfigurationPlatforms) = postSolution
+		{906CCF22-9F98-849C-F4C4-760DF67E239A}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{906CCF22-9F98-849C-F4C4-760DF67E239A}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{906CCF22-9F98-849C-F4C4-760DF67E239A}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{906CCF22-9F98-849C-F4C4-760DF67E239A}.Release|Any CPU.Build.0 = Release|Any CPU
+	EndGlobalSection
+	GlobalSection(SolutionProperties) = preSolution
+		HideSolutionNode = FALSE
+	EndGlobalSection
+	GlobalSection(ExtensibilityGlobals) = postSolution
+		SolutionGuid = {6E7574DF-1DA9-4376-9391-CD823C5D98FC}
+	EndGlobalSection
+EndGlobal

cmake/FindHipoDeps.cmake

@@ -9,14 +9,22 @@ if (WIN32)
         find_package(OpenBLAS CONFIG NO_DEFAULT_PATH)
 
         if(OpenBLAS_FOUND)
-            message(STATUS "OpenBLAS CMake config path: ${metis_DIR}")
-        else()
-            find_package(OpenBLAS CONFIG REQUIRED)
-            if(OpenBLAS_FOUND)
-                message(STATUS "OpenBLAS CMake config path: ${metis_DIR}")
+            message(STATUS "OpenBLAS CMake config path: ${OpenBLAS_DIR}")
+        endif()
+    endif()
+    if ((BLAS_ROOT STREQUAL "") OR (NOT OpenBLAS_Found))
+        find_package(OpenBLAS CONFIG REQUIRED)
+
+        if(OpenBLAS_FOUND)
+            if(TARGET OpenBLAS::OpenBLAS)
+                message(STATUS "OpenBLAS CMake config path: ${OpenBLAS_DIR}")
+            elseif(OPENBLAS_LIB)
+                message(STATUS "Linking against OpenBLAS via raw library: ${OPENBLAS_LIB}")
             endif()
+        else()
+            message(FATAL_ERROR "No BLAS library found")
         endif()
-    message(STATUS "OpenBLAS CMake config path: ${OpenBLAS_DIR}")
+    endif()
 elseif(NOT APPLE)
     # LINUX
 

highs/CMakeLists.txt

@@ -193,7 +193,7 @@ else()
 
       if(TARGET OpenBLAS::OpenBLAS)
           target_link_libraries(highs PRIVATE OpenBLAS::OpenBLAS)
-      elseif(DEFINED OPENBLAS_LIB)
+      elseif(OPENBLAS_LIB)
           message(STATUS "Linking against OpenBLAS via raw library: ${OPENBLAS_LIB}")
           target_link_libraries(highs PRIVATE ${OPENBLAS_LIB})
           target_include_directories(highs PRIVATE ${OPENBLAS_INCLUDE_DIR})
@@ -202,7 +202,7 @@ else()
       endif()
 
       target_compile_definitions(highs PRIVATE HIPO_USES_OPENBLAS)
-    else() 
+    else()
         # LINUX
         if(BLAS_LIB)
             target_link_libraries(highs "${BLAS_LIB}")