Add possibility to specify host for VS generator.

mob.ini

@@ -15,6 +15,7 @@ github_key         =
 
 [cmake]
 install_message    = never
+host               =
 
 [aliases]
 super   = cmake_common modorganizer* githubpp

src/core/conf.cpp

@@ -756,6 +756,11 @@ conf_cmake::cmake_constant conf_cmake::install_message() const
 	return read_cmake_constant("install_message", { ALWAYS, LAZY, NEVER });
 }
 
+std::string conf_cmake::host() const
+{
+	return details::get_string(name(), "host");
+}
+
 conf_cmake::cmake_constant conf_cmake::read_cmake_constant(
 	std::string_view key, std::vector<cmake_constant> const& allowed) const
 {

src/core/conf.h

@@ -192,8 +192,17 @@ public:
 public:
 	conf_cmake();
 
+	// specify the value for CMAKE_INSTALL_MESSAGE
+	//
 	cmake_constant install_message() const;
 
+	// specify the toolset host configuration, if any, this is equivalent
+	// to -T host=XXX on the command line
+	//
+	// an empty string means no host configured
+	//
+	std::string host() const;
+
 private:
 	cmake_constant read_cmake_constant(
 		std::string_view key, std::vector<cmake_constant> const& allowed) const;

src/tools/cmake.cpp

@@ -145,7 +145,8 @@ void cmake::do_generate()
 		// string
 		p
 			.arg("-G", "\"" + g.name + "\"")
-			.arg(g.get_arch(arch_));
+			.arg(g.get_arch(arch_))
+			.arg(g.get_host(conf().cmake().host()));
 	}
 	else
 	{
@@ -240,6 +241,15 @@ std::string cmake::gen_info::get_arch(arch a) const
 	}
 }
 
+std::string cmake::gen_info::get_host(std::string_view conf_host) const
+{
+	if (conf_host.empty()) {
+		return {};
+	}
+
+	return "-T host=" + std::string{ conf_host };
+}
+
 std::string cmake::gen_info::output_dir(arch a) const
 {
 	switch (a)

src/tools/cmake.h

@@ -135,6 +135,14 @@ private:
 		//
 		std::string get_arch(arch a) const;
 
+		// for generator that supports it, returns a toolset configuration to set
+		// the host as specified in the configuration
+		//
+		// for VS generator, this returns "-T host=XXX" if conf_host is not empty,
+		// otherwise returns an empty string
+		//
+		std::string get_host(std::string_view conf_host) const;
+
 		// return either `dir` for 64-bit or `dir` + "_32" for 32-bit
 		//
 		std::string output_dir(arch a) const;