Add a [cmake] section with install_message key.

mob.ini

@@ -13,6 +13,9 @@ log_file           = mob.log
 ignore_uncommitted = false
 github_key         =
 
+[cmake]
+install_message    = never
+
 [aliases]
 super   = cmake_common modorganizer* githubpp
 plugins = check_fnis bsapacker bsa_extractor diagnose_basic installer_* plugin_python preview_base preview_bsa tool_* game_*

src/core/conf.cpp

@@ -663,6 +663,11 @@ conf_task conf::task(const std::vector<std::string>& names)
 	return {names};
 }
 
+conf_cmake conf::cmake()
+{
+	return {};
+}
+
 conf_tools conf::tool()
 {
 	return {};
@@ -726,6 +731,47 @@ bool conf_task::get_bool(std::string_view key) const
 }
 
 
+bool conf_cmake::cmake_constant::is_equivalent(std::string_view other) const
+{
+	// _strcmpi does not have a n-overload, and since string_view is not
+	// necessarily null-terminated, _strmcpi cannot be safely used
+	return std::equal(
+		std::begin(value_), std::end(value_),
+		std::begin(other), std::end(other),
+		[](auto&& c1, auto&& c2) { return ::tolower(c1) == ::tolower(c2); }
+	);
+}
+
+conf_cmake::conf_cmake()
+	: conf_section("cmake")
+{
+}
+
+const conf_cmake::cmake_constant conf_cmake::ALWAYS{"always"};
+const conf_cmake::cmake_constant conf_cmake::LAZY{"lazy"};
+const conf_cmake::cmake_constant conf_cmake::NEVER{"never"};
+
+conf_cmake::cmake_constant conf_cmake::install_message() const
+{
+	return read_cmake_constant("install_message", { ALWAYS, LAZY, NEVER });
+}
+
+conf_cmake::cmake_constant conf_cmake::read_cmake_constant(
+	std::string_view key, std::vector<cmake_constant> const& allowed) const
+{
+	const auto value = details::get_string(name(), key);
+	for (const auto& constant : allowed)
+	{
+		if (constant.is_equivalent(value)) {
+			return constant;
+		}
+	}
+
+	gcx().bail_out(context::conf,
+		"bad value '{}' for {}/{} (expected one of {})",
+		value, name(), key, join(allowed, ", ", std::string{}));
+}
+
 conf_tools::conf_tools()
 	: conf_section("tools")
 {

src/core/conf.h

@@ -83,6 +83,8 @@ protected:
 	{
 	}
 
+	const auto& name() const { return name_;  }
+
 private:
 	std::string name_;
 };
@@ -151,6 +153,53 @@ private:
 };
 
 
+// options in [task] or [task_name:task]
+//
+class conf_cmake : conf_section<std::string>
+{
+public:
+	class cmake_constant {
+		std::string value_;
+
+		// check if the given string is equivalent to this constant
+		//
+		bool is_equivalent(std::string_view other) const;
+
+		friend class conf_cmake;
+
+	public:
+		constexpr cmake_constant(std::string_view value) : value_{value} { }
+		constexpr const auto& value() const { return value_; }
+		constexpr operator const std::string& () const { return value(); }
+
+
+		friend bool operator==(cmake_constant const& lhs, cmake_constant const& rhs)
+		{
+			return lhs.is_equivalent(rhs.value());
+		}
+		friend bool operator!=(cmake_constant const& lhs, cmake_constant const& rhs)
+		{
+			return !(lhs == rhs);
+		}
+
+	};
+
+	static const cmake_constant ALWAYS;
+	static const cmake_constant LAZY;
+	static const cmake_constant NEVER;
+
+
+public:
+	conf_cmake();
+
+	cmake_constant install_message() const;
+
+private:
+	cmake_constant read_cmake_constant(
+		std::string_view key, std::vector<cmake_constant> const& allowed) const;
+};
+
+
 // options in [tools]
 //
 class conf_tools : public conf_section<fs::path>
@@ -238,6 +287,7 @@ class conf
 public:
 	conf_global global();
 	conf_task task(const std::vector<std::string>& names);
+	conf_cmake cmake();
 	conf_tools tool();
 	conf_transifex transifex();
 	conf_prebuilt prebuilt();

src/tools/cmake.cpp

@@ -134,7 +134,7 @@ void cmake::do_generate()
 		.stderr_encoding(encodings::utf8)
 		.binary(binary())
 		.arg("-DCMAKE_BUILD_TYPE=Release")
-		.arg("-DCMAKE_INSTALL_MESSAGE=NEVER")
+		.arg("-DCMAKE_INSTALL_MESSAGE=" + conf().cmake().install_message().value())
 		.arg("--log-level=ERROR")
 		.arg("--no-warn-unused-cli");
 

src/utility/string.h

@@ -22,22 +22,21 @@ std::string replace_all(
 
 // concatenates all elements of `v`, separated by `sep`
 //
-template <class T, class Sep>
-T join(const std::vector<T>& v, const Sep& sep)
+template <class T, class Sep, class To = T>
+auto join(const std::vector<T>& v, const Sep& sep, To prefix = {})
 {
-	T s;
 	bool first = true;
 
 	for (auto&& e : v)
 	{
 		if (!first)
-			s += sep;
+			prefix += sep;
 
-		s += e;
+		prefix += e;
 		first = false;
 	}
 
-	return s;
+	return prefix;
 }
 
 // splits the given string on any character in `seps`