[grpc,opencv] Fix cross compile issue.

ports/grpc/00012-vcpkg-cross-compile.patch

@@ -0,0 +1,21 @@
+diff --git a/CMakeLists.txt b/CMakeLists.txt
+index ad15a31..1529acd 100644
+--- a/CMakeLists.txt
++++ b/CMakeLists.txt
+@@ -284,6 +284,16 @@ if(WIN32)
+   set(_gRPC_BASELIB_LIBRARIES wsock32 ws2_32 crypt32 gdi32)
+ endif()
+
++# VCPKG cross compile support
++if(VCPKG_HOST_TRIPLET AND NOT VCPKG_HOST_TRIPLET STREQUAL VCPKG_TARGET_TRIPLET)
++    set(CMAKE_CROSSCOMPILING ON)
++    set(_gRPC_CPP_PLUGIN "${_VCPKG_INSTALLED_DIR}/${VCPKG_HOST_TRIPLET}/tools/grpc/grpc_cpp_plugin")
++    if(NOT EXISTS "${_gRPC_CPP_PLUGIN}")
++        message(WARNING "${_gRPC_CPP_PLUGIN} is not installed. Cross compile might fail. Try to install grpc:${VCPKG_HOST_TRIPLET}")
++        unset(_gRPC_CPP_PLUGIN)
++    endif()
++endif()
++
+ # Create directory for generated .proto files
+ set(_gRPC_PROTO_GENS_DIR ${CMAKE_BINARY_DIR}/gens)
+ file(MAKE_DIRECTORY ${_gRPC_PROTO_GENS_DIR})

ports/grpc/CONTROL

@@ -1,5 +1,6 @@
 Source: grpc
 Version: 1.33.1
+Port-Version: 1
 Build-Depends: zlib, openssl, protobuf, c-ares (!uwp), upb, abseil, re2
 Homepage: https://github.com/grpc/grpc
 Description: An RPC library and framework

ports/grpc/portfile.cmake

@@ -17,6 +17,7 @@ vcpkg_from_github(
         00009-use-system-upb.patch
         00010-add-feature-absl-sync.patch
         00011-fix-csharp_plugin.patch
+        00012-vcpkg-cross-compile.patch
         snprintf.patch
 )
 

ports/protobuf/CONTROL

@@ -1,6 +1,6 @@
 Source: protobuf
 Version: 3.13.0
-Port-Version: 2
+Port-Version: 3
 Homepage: https://github.com/protocolbuffers/protobuf
 Description: Protocol Buffers - Google's data interchange format
 

ports/protobuf/vcpkg-cmake-wrapper.cmake

@@ -11,3 +11,17 @@ if(CMAKE_VERSION VERSION_GREATER_EQUAL 3.3)
     cmake_policy(POP)
 endif()
 _find_package(${ARGS})
+
+if(Protobuf_FOUND AND VCPKG_HOST_TRIPLET AND NOT VCPKG_HOST_TRIPLET STREQUAL VCPKG_TARGET_TRIPLET)
+    foreach(prop IMPORTED_LOCATION IMPORTED_LOCATION_RELEASE IMPORTED_LOCATION_DEBUG)
+        get_target_property(_protoc_exe_path protobuf::protoc ${prop})
+        if(_protoc_exe_path)
+            string(REPLACE "/${VCPKG_TARGET_TRIPLET}/" "/${VCPKG_HOST_TRIPLET}/" _protoc_exe_path "${_protoc_exe_path}")
+            if(NOT EXISTS "${_protoc_exe_path}")
+                message(WARNING "${_protoc_exe_path} is not installed. Cross compile might fail. Try to install protobuf:${VCPKG_HOST_TRIPLET}")
+            else()
+                set_target_properties(protobuf::protoc PROPERTIES ${prop} "${_protoc_exe_path}")
+            endif()
+        endif()
+    endforeach()
+endif()

scripts/buildsystems/vcpkg.cmake

@@ -213,6 +213,26 @@ endif()
 set(VCPKG_TARGET_TRIPLET ${_VCPKG_TARGET_TRIPLET_ARCH}-${_VCPKG_TARGET_TRIPLET_PLAT} CACHE STRING "Vcpkg target triplet (ex. x86-windows)")
 set(_VCPKG_TOOLCHAIN_DIR ${CMAKE_CURRENT_LIST_DIR})
 
+if(VCPKG_HOST_TRIPLET)
+    set(VCPKG_HOST_TRIPLET ${VCPKG_HOST_TRIPLET} CACHE STRING "Vcpkg host triplet (ex. arm64-linux)" FORCE)
+else()
+    if(CMAKE_HOST_SYSTEM_NAME STREQUAL "Linux")
+        set(_VCPKG_HOST_TRIPLET_PLAT linux)
+    endif()
+
+    if(CMAKE_HOST_SYSTEM_PROCESSOR STREQUAL "x86_64")
+        set(_VCPKG_TARGET_TRIPLET_ARCH x64)
+    elseif(CMAKE_HOST_SYSTEM_PROCESSOR STREQUAL "armv7l")
+        set(_VCPKG_TARGET_TRIPLET_ARCH arm)
+    elseif(CMAKE_HOST_SYSTEM_PROCESSOR STREQUAL "aarch64")
+        set(_VCPKG_TARGET_TRIPLET_ARCH arm64)
+    endif()
+
+    if(_VCPKG_HOST_TRIPLET_PLAT AND _VCPKG_TARGET_TRIPLET_ARCH)
+        set(VCPKG_HOST_TRIPLET ${_VCPKG_TARGET_TRIPLET_ARCH}-${_VCPKG_HOST_TRIPLET_PLAT} CACHE STRING "Vcpkg host triplet (ex. arm64-linux)")
+    endif()
+endif()
+
 if(NOT DEFINED _VCPKG_ROOT_DIR)
     # Detect .vcpkg-root to figure VCPKG_ROOT_DIR
     set(_VCPKG_ROOT_DIR_CANDIDATE ${CMAKE_CURRENT_LIST_DIR})