Use cmake's -C option instead of multiple -D options

bindings/ruby/ext/dependencies.rb

@@ -36,8 +36,7 @@ class Dependencies
   end
 
   def generate_dot
-    args = ["-S", "sources", "-B", "build", "--graphviz", dot_path, "-D", "BUILD_SHARED_LIBS=OFF"]
-    args << @options.to_s unless @options.to_s.empty?
+    args = ["-S", "sources", "-B", "build", "--graphviz", dot_path, "-D", "BUILD_SHARED_LIBS=OFF", "-C", @options.cache_path]
     system @cmake, *args, exception: true
   end
 

bindings/ruby/ext/extconf.rb

@@ -3,7 +3,7 @@ require_relative "options"
 require_relative "dependencies"
 
 cmake = find_executable("cmake") || abort
-options = Options.new(cmake).to_s
+options = Options.new(cmake)
 have_library("gomp") rescue nil
 libs = Dependencies.new(cmake, options).to_s
 
@@ -17,7 +17,7 @@ create_makefile "whisper" do |conf|
     $(TARGET_SO): #{libs}
     #{libs}: cmake-targets
     cmake-targets:
-    #{"\t"}#{cmake} -S sources -B build -D BUILD_SHARED_LIBS=OFF -D CMAKE_ARCHIVE_OUTPUT_DIRECTORY=#{__dir__} -D CMAKE_POSITION_INDEPENDENT_CODE=ON #{options}
+    #{"\t"}#{cmake} -S sources -B build -D BUILD_SHARED_LIBS=OFF -D CMAKE_ARCHIVE_OUTPUT_DIRECTORY=#{__dir__} -D CMAKE_POSITION_INDEPENDENT_CODE=ON -C #{options.cache_path}
     #{"\t"}#{cmake} --build build --config Release --target common whisper
   EOF
 end

bindings/ruby/ext/options.rb

@@ -1,16 +1,16 @@
+require "fileutils"
+
 class Options
   def initialize(cmake="cmake")
     @cmake = cmake
     @options = {}
 
     configure
+    write_cache_file
   end
 
-  def to_s
-    @options
-      .reject {|name, (type, value)| value.nil?}
-      .collect {|name, (type, value)| "-D #{name}=#{value == true ? "ON" : value == false ? "OFF" : value.shellescape}"}
-      .join(" ")
+  def cache_path
+    File.join(__dir__, "source", "Options.cmake")
   end
 
   def cmake_options
@@ -82,4 +82,22 @@ class Options
       op[1]
     end
   end
+
+  def write_cache_file
+    FileUtils.mkpath File.dirname(cache_path)
+    File.open cache_path, "w" do |file|
+      @options.reject {|name, (type, value)| value.nil?}.each do |name, (type, value)|
+        line = "set(CACHE{%<name>s} TYPE %<type>s FORCE VALUE %<value>s)" % {
+          name:,
+          type:,
+          value: value == true ? "ON" : value == false ? "OFF" : escape_cmake(value)
+        }
+        file.puts line
+      end
+    end
+  end
+
+  def escape_cmake(str)
+    str.gsub(/([\\"])/, '\\\\\1')
+  end
 end