Add tool to compare native image flags from --verbose output

Author: eregon

tool/extract-native-image-flags.rb

@@ -0,0 +1,61 @@
+lines = ARGF.readlines(chomp: true)
+lines.each do |line|
+  line.sub!(/^\[lib[^:]+:\d+\]\s+/, '')
+  line.sub!(/\s*\\$/, '')
+  line.sub!(/^'(.+)'$/, '\1')
+  line.sub!(/^(.+?)@(?:--macro|--language|--tool|jar|user|driver)[^=]*=(.*)$/, '\1=\2')
+  line.sub!(/^(.+?)@(?:--macro|--language|--tool|jar|user|driver)[^=]*$/, '\1')
+end
+lines.reject! { _1.start_with?("Apply jar") }
+lines.delete("Executing [")
+lines.delete("]")
+
+to_merge_in_one_line = %w[
+  --add-exports
+  --module-path
+  --module
+  -imagecp
+  -imagemp
+  -keepalive
+]
+
+to_merge_in_one_line.each do |option|
+  lines.each_cons(2) do |a, b|
+    if a == option
+      b.prepend "#{option}="
+    end
+  end
+  lines.delete option
+end
+
+lines.sort!
+lines.uniq!
+
+fields_to_sort_value = %w[
+  --module-path=
+  -imagecp=
+  -imagemp=
+
+  --add-modules=
+  --enable-native-access=
+  -Dorg.graalvm.launcher.classpath=
+  -Dsvm.modulesupport.addedModules=
+  -H:CLibraryPath=
+]
+lines.each do |line|
+  if fields_to_sort_value.any? { |f| line.start_with?(f) }
+    key, value = line.split('=', 2)
+    # sep = %w[-Dorg.graalvm.launcher.classpath=].include?(key) ? ':' : ','
+    values = value.split(/[,:]/)
+    if value.include?('/') # contains paths
+      values = values.map { File.basename(_1) }
+    end
+    values = values.sort.uniq
+    # value = values.join(',')
+    value = "[\n#{values.join("\n")}\n]"
+
+    line.replace "#{key}=#{value}"
+  end
+end
+
+puts lines