reducing duplicate CONSTANT_VALUE reads into FieldConstants

Author: nklapste

src/main/java/jadx/plugins/stringdecoder/B64DeobfuscatePass.java

@@ -12,9 +12,6 @@
 import java.util.stream.IntStream;
 
 import jadx.api.data.CommentStyle;
-import jadx.api.plugins.input.data.annotations.EncodedType;
-import jadx.api.plugins.input.data.annotations.EncodedValue;
-import jadx.api.plugins.input.data.attributes.JadxAttrType;
 import jadx.api.plugins.pass.JadxPassInfo;
 import jadx.api.plugins.pass.impl.OrderedJadxPassInfo;
 import jadx.api.plugins.pass.types.JadxDecompilePass;
@@ -291,13 +288,9 @@ private static boolean isUsedAsBase64DecodeArg(ConstStringNode csn) {
 	private static Set<String> collectConstantValueFieldStrings(ClassNode cls) {
 		Set<String> result = new HashSet<>();
 		for (FieldNode field : cls.getFields()) {
-			EncodedValue cv = field.get(JadxAttrType.CONSTANT_VALUE);
-			if (cv == null || cv.getType() != EncodedType.ENCODED_STRING) {
-				continue;
-			}
-			Object val = cv.getValue();
-			if (val instanceof String) {
-				result.add((String) val);
+			String val = FieldConstants.readStringValue(field);
+			if (val != null) {
+				result.add(val);
 			}
 		}
 		return result.isEmpty() ? Collections.emptySet() : result;

src/main/java/jadx/plugins/stringdecoder/B64FieldInitPass.java

@@ -2,9 +2,6 @@
 
 import java.util.TreeMap;
 
-import jadx.api.plugins.input.data.annotations.EncodedType;
-import jadx.api.plugins.input.data.annotations.EncodedValue;
-import jadx.api.plugins.input.data.attributes.JadxAttrType;
 import jadx.api.plugins.pass.JadxPassInfo;
 import jadx.api.plugins.pass.impl.OrderedJadxPassInfo;
 import jadx.api.plugins.pass.types.JadxDecompilePass;
@@ -65,7 +62,7 @@ private void processField(FieldNode field) {
 			return;
 		}
 		// static final field with literal value encoded in the class file (no <clinit>).
-		String constStr = readConstantStringValue(field);
+		String constStr = FieldConstants.readStringValue(field);
 		if (constStr != null) {
 			annotateField(field, constStr, false);
 		}
@@ -125,7 +122,7 @@ private static String extractStringFromArg(FieldNode contextField, InsnArg arg)
 		}
 		if (argInsn != null && argInsn.getType() == InsnType.SGET) {
 			FieldNode refField = resolveFieldFromSget(contextField, (IndexInsnNode) argInsn);
-			return refField != null ? readConstantStringValue(refField) : null;
+			return refField != null ? FieldConstants.readStringValue(refField) : null;
 		}
 		return null;
 	}
@@ -171,7 +168,7 @@ private boolean annotateFromSgetReference(FieldNode consumingField, IndexInsnNod
 		if (refField == null) {
 			return false;
 		}
-		String str = readConstantStringValue(refField);
+		String str = FieldConstants.readStringValue(refField);
 		if (str == null || !annotateField(consumingField, str, isBase64Call)) {
 			return false;
 		}
@@ -190,15 +187,6 @@ private static FieldNode resolveFieldFromSget(FieldNode contextField, IndexInsnN
 		return declCls != null ? declCls.searchField(refFieldInfo) : null;
 	}
 
-	private static String readConstantStringValue(FieldNode field) {
-		EncodedValue cv = field.get(JadxAttrType.CONSTANT_VALUE);
-		if (cv == null || cv.getType() != EncodedType.ENCODED_STRING) {
-			return null;
-		}
-		Object val = cv.getValue();
-		return val instanceof String ? (String) val : null;
-	}
-
 	private static InsnNode resolveArgInsn(InsnArg arg) {
 		if (arg instanceof InsnWrapArg) {
 			return ((InsnWrapArg) arg).getWrapInsn();

src/main/java/jadx/plugins/stringdecoder/FieldConstants.java

@@ -0,0 +1,27 @@
+package jadx.plugins.stringdecoder;
+
+import jadx.api.plugins.input.data.annotations.EncodedType;
+import jadx.api.plugins.input.data.annotations.EncodedValue;
+import jadx.api.plugins.input.data.attributes.JadxAttrType;
+import jadx.core.dex.nodes.FieldNode;
+
+/**
+ * Reads compile-time constant values baked into a field by the class file — i.e. a {@code static
+ * final} field's {@code CONSTANT_VALUE} attribute, as opposed to a value assigned in {@code <clinit>}
+ * or a constructor (which {@code ExtractFieldInit} surfaces as a {@code FIELD_INIT_INSN}).
+ */
+final class FieldConstants {
+
+	private FieldConstants() {
+	}
+
+	/** The field's {@code CONSTANT_VALUE} string literal, or null if it has none / isn't a string. */
+	static String readStringValue(FieldNode field) {
+		EncodedValue cv = field.get(JadxAttrType.CONSTANT_VALUE);
+		if (cv == null || cv.getType() != EncodedType.ENCODED_STRING) {
+			return null;
+		}
+		Object val = cv.getValue();
+		return val instanceof String ? (String) val : null;
+	}
+}