Add support for <clinit> in ConfigurationParser

Author: bengt-GS

base/src/main/java/proguard/ConfigurationParser.java

@@ -1183,24 +1183,29 @@ else if (isMethods)
             // Did we get just one word before the opening parenthesis?
             if (ConfigurationConstants.OPEN_ARGUMENTS_KEYWORD.equals(name))
             {
-                // This must be a constructor then.
-                // Make sure the type is a proper constructor name.
-                if (!(type.equals(ClassConstants.METHOD_NAME_INIT) ||
-                      type.equals(externalClassName) ||
-                      type.equals(ClassUtil.externalShortClassName(externalClassName))))
+                // This must be an initializer then.
+                // Make sure the type is a proper initializer name.
+                if (ClassUtil.isInitializer(type))
+                {
+                    name = type; // This is either `<init>` or `<clinit>`.
+                    type = JavaTypeConstants.VOID;
+                }
+                else if (type.equals(externalClassName) ||
+                         type.equals(ClassUtil.externalShortClassName(externalClassName)))
+                {
+                    name = ClassConstants.METHOD_NAME_INIT;
+                    type = JavaTypeConstants.VOID;
+                }
+                else
                 {
                     throw new ParseException("Expecting type and name " +
                                              "instead of just '" + type +
                                              "' before " + reader.locationDescription());
                 }
-
-                // Assign the fixed constructor type and name.
-                type = JavaTypeConstants.VOID;
-                name = ClassConstants.METHOD_NAME_INIT;
             }
             else
             {
-                // It's not a constructor.
+                // It's not an initializer.
                 // Make sure we have a proper name.
                 checkNextWordIsJavaIdentifier("class member name");
 
@@ -1211,7 +1216,7 @@ else if (isMethods)
             }
 
             // Check if the type actually contains the use of generics.
-            // Can not do it right away as we also support "<init>" as a type (see case above).
+            // Can not do it right away as we also support "<init>" and "<clinit>" as a type (see case above).
             if (containsGenerics(type))
             {
                 throw new ParseException("Generics are not allowed (erased) for java type" + typeLocation);
@@ -1292,6 +1297,14 @@ else if (ConfigurationConstants.OPEN_ARGUMENTS_KEYWORD.equals(nextWord))
                                              "' before " + reader.locationDescription());
                 }
 
+                // Class initializers are not supposed to have any parameters.
+                if (ClassConstants.METHOD_NAME_CLINIT.equals(name) &&
+                    ClassUtil.internalMethodParameterCount(descriptor) > 0)
+                {
+                    throw new ParseException("Not expecting method parameters with initializer '" + ClassConstants.METHOD_NAME_CLINIT +
+                                             "' before " + reader.locationDescription());
+                }
+
                 // Read the separator after the closing parenthesis.
                 readNextWord("separator '" + ConfigurationConstants.SEPARATOR_KEYWORD + "'");
 

base/src/test/kotlin/proguard/ConfigurationParserTest.kt

@@ -64,6 +64,31 @@ class ConfigurationParserTest : FreeSpec({
             parseConfiguration("-keep class * { public protected <methods>; }")
         }
 
+        "Keep rule with ClassName should be valid" {
+            val configuration = parseConfiguration("-keep class ClassName { ClassName(); }")
+            val keep = configuration.keep.single().methodSpecifications.single()
+            keep.name shouldBe "<init>"
+            keep.descriptor shouldBe "()V"
+        }
+
+        "Keep rule with ClassName and external class com.example.ClassName should be valid" {
+            val configuration = parseConfiguration("-keep class com.example.ClassName { ClassName(); }")
+            val keep = configuration.keep.single().methodSpecifications.single()
+            keep.name shouldBe "<init>"
+            keep.descriptor shouldBe "()V"
+        }
+
+        "Keep rule with <clinit> should be valid" {
+            val configuration = parseConfiguration("-keep class ** { <clinit>(); }")
+            val keep = configuration.keep.single().methodSpecifications.single()
+            keep.name shouldBe "<clinit>"
+            keep.descriptor shouldBe "()V"
+        }
+
+        "Keep rule with <clinit> and non-empty argument list should throw ParseException" {
+            shouldThrow<ParseException> { parseConfiguration("-keep class * { void <clinit>(int) }") }
+        }
+
         "Keep rule with * member wildcard and return type should be valid" {
             parseConfiguration("-keep class * { java.lang.String *; }")
         }

base/src/test/kotlin/proguard/ConfigurationWriterTest.kt

@@ -26,6 +26,48 @@ class ConfigurationWriterTest : FreeSpec({
         return out.toString().trim()
     }
 
+    "Keep rules tests" - {
+        "Keep class constructor should be kept" {
+            val rules = """
+                -keep class * {
+                    <init>();
+                }
+            """.trimIndent()
+            val out = printConfiguration(rules)
+            out shouldBe rules
+        }
+
+        "Keep class initializer should be kept" {
+            val rules = """
+                -keep class * {
+                    <clinit>();
+                }
+            """.trimIndent()
+            val out = printConfiguration(rules)
+            val expected = """
+                -keep class * {
+                    void <clinit>();
+                }
+            """.trimIndent()
+            out shouldBe expected
+        }
+
+        "Keep class initializer should respect allowobfuscation flag" {
+            val rules = """
+                -keep,allowobfuscation class ** extends com.example.A {
+                    <clinit>();
+                }
+            """.trimIndent()
+            val out = printConfiguration(rules)
+            val expected = """
+                -keep,allowobfuscation class ** extends com.example.A {
+                    void <clinit>();
+                }
+            """.trimIndent()
+            out shouldBe expected
+        }
+    }
+
     "Hash character handling tests" - {
         "Option parameters with hash characters should be quoted" {
             printConfiguration("-keystorepassword '#tester'") shouldBe "-keystorepassword '#tester'"

docs/md/manual/releasenotes.md

@@ -4,6 +4,10 @@
 
 - Fix inadvertent closing of System.out when printing configuration. (#365)
 
+### Added
+
+- Support for parsing of `<clinit>` methods without specifying the return type in class specifications.
+
 ## Version 7.4
 
 ### Java support