Support cross-build in corehost

- Add ability to specify `cross` and `C++ Cross Compiler`
when building corehost for ARM.
- Add usage print in the corehost build script
- Fix bugs found on the cross compiler

Signed-off-by: Dongyun Jin <dongyun.jin@samsung.com>

src/corehost/build.sh

@@ -4,6 +4,19 @@
 # I really don't know, but it doesn't work when I do that. Something about SIGCHLD not getting from clang to cmake or something.
 #       -anurse
 
+usage()
+{
+    echo "Usage: $0 --arch <Architecture> --rid <Runtime Identifier> [--xcompiler <Cross C++ Compiler>]"
+    echo ""
+    echo "Options:"
+    echo "  --arch <Architecture>             Target Architecture (amd64, x86, arm)"
+    echo "  --rid <Runtime Identifier>        Target Runtime Identifier"
+    echo "  --xcompiler <Cross C++ Compiler>  Cross Compiler when the target is arm"
+    echo "                                    e.g.) /usr/bin/arm-linux-gnueabi-g++-4.7"
+
+    exit 1
+}
+
 set -e
 
 SOURCE="${BASH_SOURCE[0]}"
@@ -16,6 +29,7 @@ DIR="$( cd -P "$( dirname "$SOURCE" )" && pwd )"
 
 __build_arch=
 __runtime_id=
+__CrossBuild=0
 
 while [ "$1" != "" ]; do
         lowerI="$(echo $1 | awk '{print tolower($0)}')"
@@ -32,6 +46,11 @@ while [ "$1" != "" ]; do
             shift
             __runtime_id=$1
             ;;
+        --xcompiler)
+            shift
+            __CrossCompiler="$1"
+            __CrossBuild=1
+            ;;
         *)
         echo "Unknown argument to build.sh $1"; exit 1
     esac
@@ -47,6 +66,9 @@ case $__build_arch in
     x86)
         __define=-DCLI_CMAKE_PLATFORM_ARCH_I386=1
         ;;
+    arm)
+        __define=-DCLI_CMAKE_PLATFORM_ARCH_ARM=1
+        ;;
     *)
         echo "Unknown architecture $__build_arch"; exit 1
         ;;
@@ -55,5 +77,9 @@ __cmake_defines="${__cmake_defines} ${__define}"
 
 
 echo "Building Corehost from $DIR to $(pwd)"
-cmake "$DIR" -G "Unix Makefiles" $__cmake_defines -DCLI_CMAKE_RUNTIME_ID:STRING=$__runtime_id
+if [ $__CrossBuild == 1 ]; then
+    cmake "$DIR" -G "Unix Makefiles" $__cmake_defines -DCLI_CMAKE_RUNTIME_ID:STRING=$__runtime_id -DCMAKE_CXX_COMPILER="$__CrossCompiler"
+else
+    cmake "$DIR" -G "Unix Makefiles" $__cmake_defines -DCLI_CMAKE_RUNTIME_ID:STRING=$__runtime_id
+fi
 make

src/corehost/cli/json/casablanca/include/cpprest/json.h

@@ -313,7 +313,7 @@ public:
         /// <param name="fields">Field names associated with JSON values</param>
         /// <param name="keep_order">Whether to preserve the original order of the fields</param>
         /// <returns>A non-empty JSON object value</returns>
-        static _ASYNCRTIMP json::value __cdecl object(std::vector<std::pair<::utility::string_t, value>> fields, bool keep_order = false);
+        static _ASYNCRTIMP json::value __cdecl object(std::vector<std::pair<utility::string_t, value>> fields, bool keep_order = false);
 
         /// <summary>
         /// Creates an empty JSON array

src/corehost/cli/json/casablanca/src/json/json.cpp

@@ -237,7 +237,7 @@ web::json::value web::json::value::object(bool keep_order)
             );
 }
 
-web::json::value web::json::value::object(std::vector<std::pair<::utility::string_t, value>> fields, bool keep_order)
+web::json::value web::json::value::object(std::vector<std::pair<utility::string_t, value>> fields, bool keep_order)
 {
     std::unique_ptr<details::_Value> ptr = utility::details::make_unique<details::_Object>(std::move(fields), keep_order);
     return web::json::value(std::move(ptr)

src/corehost/cli/setup.cmake

@@ -41,6 +41,8 @@ if(CLI_CMAKE_PLATFORM_ARCH_I386)
     add_definitions(-D_TARGET_X86_=1)
 elseif(CLI_CMAKE_PLATFORM_ARCH_AMD64)
     add_definitions(-D_TARGET_AMD64_=1)
+elseif(CLI_CMAKE_PLATFORM_ARCH_ARM)
+    add_definitions(-D_TARGET_ARM_=1)
 else()
     message(FATAL_ERROR "Unknown target architecture")
 endif()

src/corehost/common/utils.cpp

@@ -121,6 +121,8 @@ const pal::char_t* get_arch()
     return _X("x64");
 #elif _TARGET_X86_
     return _X("x86");
+#elif _TARGET_ARM_
+    return _X("arm");
 #else
 #error "Unknown target"
 #endif