[lapack-reference|fortran] Add new port (#12805)

* [vcpkg/script] add vcpkg_find_fortran

* [openblas] add pkg-config fixes

* [lapack] add lapack-reference and reduce dependency on clapack

* fix build issues

* dont touch any main files

* move toolchain var into parent scope

* fix a few more issues

* create link in the noblas case

* removed unnecessary check handled by vcpkg_find_fortran.

* move dumpbin check

* fix last issue

* depend on openblas

* set cmake_binary_dir so that compiler id run gets put into buildtree.

* more paths

* add missing PARENT_SCOPE

* ws change

* [mlpack] remove dep on clapack

* comment out patches

* remove openblas again

* Install lapack wrapper since it is missing linkage against -lm and -lgfortran

* PREPEND mingw path to make sure cmake picks it up correctly

* depend on openblas also on osx

* add clapack on windows to skip due to conflicting library installs

* add clapack to skip on linux

* add -fPIC as a fortran compiler flag

* do not add the flag on windows

* add gcc explicitly to the cmake args.

* ws change

* applyrequested changes from CR

* fix the failing patch

2 files changed, 66 insertions, 0 deletions

diff --git a/scripts/ci.baseline.txt b/scripts/ci.baseline.txt
index a6cc7c886..9bf7bcf16 100644
--- a/scripts/ci.baseline.txt
+++ b/scripts/ci.baseline.txt
@@ -208,6 +208,11 @@ chmlib:x64-uwp=fail
 civetweb:arm64-windows      = skip
 civetweb:arm-uwp            = skip
 civetweb:x64-uwp            = skip
+# clapack is replaced by lapack-reference. 
+clapack:x64-linux = skip
+clapack:x64-windows = skip
+clapack:x64-windows-static = skip
+clapack:x86-windows = skip
 clapack:x64-uwp=fail
 clblas:arm64-windows=fail
 clblast:x64-linux=fail
diff --git a/scripts/cmake/vcpkg_find_fortran.cmake b/scripts/cmake/vcpkg_find_fortran.cmake
new file mode 100644
index 000000000..e6be2722e
--- /dev/null
+++ b/scripts/cmake/vcpkg_find_fortran.cmake
@@ -0,0 +1,61 @@
+## # vcpkg_find_fortran

+##

+## Checks if a Fortran compiler can be found.

+## Windows(x86/x64) Only: If not it will switch/enable MinGW gfortran 

+##                        and return required cmake args for building. 

+##

+## ## Usage

+## ```cmake

+## vcpkg_find_fortran(<additional_cmake_args_out>

+## )

+## ```

+

+function(vcpkg_find_fortran additional_cmake_args_out)

+    set(ARGS_OUT)

+    set(CMAKE_BINARY_DIR "${CURRENT_BUILDTREES_DIR}/${TARGET_TRIPLET}")

+    set(CMAKE_CURRENT_BINARY_DIR "${CMAKE_BINARY_DIR}")

+    set(CMAKE_PLATFORM_INFO_DIR "${CMAKE_BINARY_DIR}/Platform")

+    include(CMakeDetermineFortranCompiler)

+    if(NOT CMAKE_Fortran_COMPILER AND NOT VCPKG_CHAINLOAD_TOOLCHAIN_FILE)

+    # This intentionally breaks users with a custom toolchain which do not have a Fortran compiler setup

+    # because they either need to use a port-overlay (for e.g. lapack), remove the toolchain for the port using fortran

+    # or setup fortran in their VCPKG_CHAINLOAD_TOOLCHAIN_FILE themselfs!

+        if(WIN32)

+            message(STATUS "No Fortran compiler found on the PATH. Using MinGW gfortran!")

+            # If no Fortran compiler is on the path we switch to use gfortan from MinGW within vcpkg

+            set(VCPKG_CHAINLOAD_TOOLCHAIN_FILE "${SCRIPTS}/toolchains/mingw.cmake") # Switching to mingw toolchain

+            if(VCPKG_TARGET_ARCHITECTURE STREQUAL "x86")

+                set(MINGW_PATH mingw32)

+                set(MSYS_TARGET i686)

+                set(MACHINE_FLAG -m32)

+            elseif(VCPKG_TARGET_ARCHITECTURE STREQUAL "x64")

+                set(MINGW_PATH mingw64)

+                set(MSYS_TARGET x86_64)

+                set(MACHINE_FLAG -m64)

+            else()

+                message(FATAL_ERROR "Unknown architecture '${VCPKG_TARGET_ARCHITECTURE}' for MinGW Fortran build!")

+            endif()

+            vcpkg_acquire_msys(MSYS_ROOT "mingw-w64-${MSYS_TARGET}-gcc-fortran")

+            set(MINGW_BIN "${MSYS_ROOT}/${MINGW_PATH}/bin")

+            vcpkg_add_to_path(PREPEND "${MINGW_BIN}")

+            list(APPEND ARGS_OUT -DCMAKE_GNUtoMS=ON

+                                 "-DCMAKE_Fortran_COMPILER=${MINGW_BIN}/gfortran.exe"

+                                 "-DCMAKE_C_COMPILER=${MINGW_BIN}/gcc.exe"

+                                 "-DCMAKE_Fortran_FLAGS_INIT:STRING= -mabi=ms ${MACHINE_FLAG} ${VCPKG_Fortran_FLAGS}")

+            set(VCPKG_USE_INTERNAL_Fortran TRUE PARENT_SCOPE)

+            set(VCPKG_POLICY_SKIP_DUMPBIN_CHECKS enabled PARENT_SCOPE)

+            set(VCPKG_CHAINLOAD_TOOLCHAIN_FILE "${SCRIPTS}/toolchains/mingw.cmake" PARENT_SCOPE) # Switching to MinGW toolchain for Fortran

+            if(VCPKG_CRT_LINKAGE STREQUAL "static")

+                set(VCPKG_CRT_LINKAGE dynamic PARENT_SCOPE)

+                message(STATUS "VCPKG_CRT_LINKAGE linkage for ${PORT} using vcpkg's internal gfortran cannot be static due to linking against MinGW libraries. Forcing dynamic CRT linkage")

+            endif()

+            if(VCPKG_LIBRARY_LINKAGE STREQUAL "static")

+                set(VCPKG_LIBRARY_LINKAGE dynamic PARENT_SCOPE)

+                message(STATUS "VCPKG_LIBRARY_LINKAGE linkage for ${PORT} using vcpkg's internal gfortran cannot be static due to linking against MinGW libraries. Forcing dynamic library linkage")

+            endif()

+        else()

+            message(FATAL_ERROR "Unable to find a Fortran compiler using 'CMakeDetermineFortranCompiler'. Please install one (e.g. gfortran) and make it available on the PATH!")

+        endif()

+    endif()

+    set(${additional_cmake_args_out} ${ARGS_OUT} PARENT_SCOPE)

+endfunction()
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