Fix the problem where proguard strips interface information.

Makefile

@@ -6,6 +6,8 @@ SRC_DIR := src
 
 RES_DIR := res
 
+PHEADERS = $(HEADERS):$(JAVA_HOME)/jre/lib/rt.jar
+
 rwildcard=$(wildcard $1$2) $(foreach d,$(wildcard $1*),$(call rwildcard,$d/,$2))
 
 SRCS := $(call rwildcard,$(SRC_DIR),*.kt)
@@ -33,7 +35,7 @@ jars/result.jar: jars/classes.jar
 	jar -umf META-INF/MANIFEST.MF jars/result.jar -C res .
 
 release jars/release.jar: jars/result.jar
-	proguard -include proguard.conf -keepclassmembers class $(CLASSNAME) { public \<methods\> ';' } 
+	proguard -include proguard.conf -libraryjars $(PHEADERS) -keepclassmembers class $(CLASSNAME) { public \<methods\> ';' } -keep public class $(CLASSNAME)
 
 run:
 	$(EMULATOR) jars/result.jar 

default.mk

@@ -2,4 +2,5 @@ HEADERS =
 EMULATOR = java -jar
 RETROTRANSLATOR = java -jar
 PROGUARD = java -jar
+JAVA_HOME = /usr/lib/jvm/openjdk8
 

proguard.conf

@@ -1,5 +1,7 @@
 -injars jars/result.jar(!**.kotlin_builtins,!META-INF/main.kotlin_module,!META-INF/services/**)
 -outjars jars/release.jar
--dontwarn 
--keep public class com.Hello 
+-dontwarn org.jetbrains.**
+-dontwarn net.sf.retrotranslator.**
+-dontwarn edu.emory.mathcs.backport.**
+-dontwarn kotlin.**
 -microedition