support more types to hide from toString method

sample/src/main/kotlin/KSPTest.kt

@@ -3,11 +3,14 @@ import dev.datlag.sekret.Secret
 
 @Obfuscate
 data class KSPTest<T>(
-    val data: String,
+    @Secret val data: java.lang.String,
     @Secret val secret: String,
     val testing: Int = 1337,
     val subClass: Sub = Sub("sub-data"),
-    @Secret val charSeq: CharSequence = "abcdefg"
+    @Secret val charSeq: CharSequence = "abcdefg",
+    @Secret val javaCharSeq: java.lang.CharSequence = secret as java.lang.CharSequence,
+    @Secret val builder: StringBuilder = StringBuilder("string-builder"),
+    @Secret val appendable: Appendable = builder
 ) {
     val other: String = "test"
 }

sample/src/main/kotlin/Main.kt

@@ -15,7 +15,7 @@ fun main() {
         val secretValue = Sekret.testKey("password12345")
         println("Decoded secret: $secretValue")
     }
-    val testing = KSPTest<Int>("my-data", "my-secret")
+    val testing = KSPTest<Int>(java.lang.String("java-string"), "my-secret")
     println(testing.toString())
     println(testing.secret)
     println(testing.charSeq)

sekret-compiler-plugin/src/main/kotlin/dev/datlag/sekret/ElementTransformer.kt

@@ -1,34 +1,16 @@
 package dev.datlag.sekret
 
-import dev.datlag.sekret.common.hasMatchingAnnotation
-import dev.datlag.sekret.common.matchesAnyProperty
-import dev.datlag.sekret.common.matchesProperty
+import dev.datlag.sekret.common.*
 import org.jetbrains.kotlin.backend.common.IrElementTransformerVoidWithContext
-import org.jetbrains.kotlin.backend.common.extensions.FirIncompatiblePluginAPI
 import org.jetbrains.kotlin.backend.common.extensions.IrPluginContext
 import org.jetbrains.kotlin.backend.common.lower.DeclarationIrBuilder
-import org.jetbrains.kotlin.backend.wasm.ir2wasm.allFields
-import org.jetbrains.kotlin.backend.wasm.utils.hasWasmAutoboxedAnnotation
-import org.jetbrains.kotlin.descriptors.DescriptorVisibilities
 import org.jetbrains.kotlin.ir.IrStatement
-import org.jetbrains.kotlin.ir.ObsoleteDescriptorBasedAPI
-import org.jetbrains.kotlin.ir.builders.declarations.addFunction
-import org.jetbrains.kotlin.ir.builders.declarations.buildFun
-import org.jetbrains.kotlin.ir.builders.irBlockBody
-import org.jetbrains.kotlin.ir.builders.irCall
-import org.jetbrains.kotlin.ir.builders.irReturn
 import org.jetbrains.kotlin.ir.builders.irString
 import org.jetbrains.kotlin.ir.declarations.*
 import org.jetbrains.kotlin.ir.expressions.*
-import org.jetbrains.kotlin.ir.types.isCharSequence
-import org.jetbrains.kotlin.ir.types.isNullableString
-import org.jetbrains.kotlin.ir.types.isString
-import org.jetbrains.kotlin.ir.types.typeConstructorParameters
+import org.jetbrains.kotlin.ir.types.*
 import org.jetbrains.kotlin.ir.util.*
 import org.jetbrains.kotlin.name.FqName
-import org.jetbrains.kotlin.name.Name
-import org.jetbrains.kotlin.resolve.jvm.annotations.findSynchronizedAnnotation
-import org.jetbrains.kotlin.resolve.source.getPsi
 
 class ElementTransformer(
     private val config: Config,
@@ -42,7 +24,7 @@ class ElementTransformer(
 
         val secretProperties = declaration.properties.filter { it.hasMatchingAnnotation(secretAnnotation, declaration) }
         if (secretProperties.count() > 0) {
-            declaration.getSimpleFunction("toString")?.owner?.transform(
+            declaration.getSimpleFunction("toString")?.owner?.transformChildren(
                 ToStringTransformer(secretProperties.toList(), config, logger, pluginContext),
                 null
             )
@@ -59,10 +41,12 @@ class ToStringTransformer(
     private val pluginContext: IrPluginContext
 ) : IrElementTransformerVoidWithContext() {
     override fun visitGetField(expression: IrGetField): IrExpression {
-        val stringField = expression.type.isString() || (config.secretMaskNull && expression.type.isNullableString())
-        val charSequence = expression.type.isCharSequence()
+        val string = expression.type.isAnyString(config.secretMaskNull)
+        val charSequence = expression.type.isAnyCharSequence(config.secretMaskNull)
+        val stringBuilder = expression.type.isAnyStringBuilder(config.secretMaskNull)
+        val appendable = expression.type.isAnyAppendable(config.secretMaskNull)
 
-        if (stringField || charSequence) {
+        if (string || charSequence || stringBuilder || appendable) {
             if (expression.symbol.owner.matchesAnyProperty(secretProperties)) {
                 return DeclarationIrBuilder(pluginContext, expression.symbol).irString(config.secretMask)
             }

sekret-compiler-plugin/src/main/kotlin/dev/datlag/sekret/JavaSignatureValues.kt

@@ -0,0 +1,10 @@
+package dev.datlag.sekret
+
+import org.jetbrains.kotlin.ir.types.getPublicSignature
+
+object JavaSignatureValues {
+    @JvmField val string = getPublicSignature(JavaStandardNames.LANG_PACKAGE_FQ_NAME, "String")
+    @JvmField val charSequence = getPublicSignature(JavaStandardNames.LANG_PACKAGE_FQ_NAME, "CharSequence")
+    @JvmField val stringBuilder = getPublicSignature(JavaStandardNames.LANG_PACKAGE_FQ_NAME, "StringBuilder")
+    @JvmField val appendable = getPublicSignature(JavaStandardNames.LANG_PACKAGE_FQ_NAME, "Appendable")
+}

sekret-compiler-plugin/src/main/kotlin/dev/datlag/sekret/JavaStandardNames.kt

@@ -0,0 +1,16 @@
+package dev.datlag.sekret
+
+import org.jetbrains.kotlin.name.FqName
+import org.jetbrains.kotlin.name.Name
+
+object JavaStandardNames {
+
+    @JvmField
+    val BUILT_INS_PACKAGE_NAME = Name.identifier("java")
+
+    @JvmField
+    val BUILT_INS_PACKAGE_FQ_NAME = FqName.topLevel(BUILT_INS_PACKAGE_NAME)
+
+    @JvmField
+    val LANG_PACKAGE_FQ_NAME = BUILT_INS_PACKAGE_FQ_NAME.child(Name.identifier("lang"))
+}

sekret-compiler-plugin/src/main/kotlin/dev/datlag/sekret/common/ExtendIr.kt

@@ -1,8 +1,11 @@
 package dev.datlag.sekret.common
 
+import dev.datlag.sekret.JavaSignatureValues
+import org.jetbrains.kotlin.builtins.StandardNames
 import org.jetbrains.kotlin.ir.declarations.IrClass
 import org.jetbrains.kotlin.ir.declarations.IrField
 import org.jetbrains.kotlin.ir.declarations.IrProperty
+import org.jetbrains.kotlin.ir.types.*
 import org.jetbrains.kotlin.ir.util.*
 import org.jetbrains.kotlin.name.FqName
 
@@ -56,4 +59,43 @@ fun IrField.matchesProperty(property: IrProperty): Boolean {
 
 fun IrField.matchesAnyProperty(properties: Iterable<IrProperty>): Boolean {
     return properties.any { this.matchesProperty(it) }
+}
+
+fun IrType.matches(signature: IdSignature.CommonSignature, nullable: Boolean? = null): Boolean {
+    if (this !is IrSimpleType) return false
+    if (nullable != null && this.isMarkedNullable() != nullable) return false
+    return signature == classifier.signature ||
+            classifier.owner.let { it is IrClass && it.signatureMatchesFqName(signature) }
+}
+
+fun IrClass.signatureMatchesFqName(signature: IdSignature.CommonSignature): Boolean =
+    name.asString() == signature.shortName &&
+            hasEqualFqName(FqName("${signature.packageFqName}.${signature.declarationFqName}"))
+
+fun IrType.matchesPossibleNull(signature: IdSignature.CommonSignature, nullable: Boolean = false): Boolean {
+    return matches(signature, false) || (nullable && matches(signature, true))
+}
+
+fun IrType.isAnyString(nullable: Boolean = false): Boolean {
+    return this.matchesPossibleNull(IdSignatureValues.string, nullable = nullable)
+            || this.matchesPossibleNull(JavaSignatureValues.string, nullable = nullable)
+}
+
+fun IrType.isAnyCharSequence(nullable: Boolean = false): Boolean {
+    return this.matchesPossibleNull(IdSignatureValues.charSequence, nullable = nullable)
+            || this.matchesPossibleNull(JavaSignatureValues.charSequence, nullable = nullable)
+}
+
+fun IrType.isAnyStringBuilder(nullable: Boolean = false): Boolean {
+    return this.matchesPossibleNull(
+        getPublicSignature(StandardNames.TEXT_PACKAGE_FQ_NAME, "StringBuilder"),
+        nullable = nullable
+    ) || this.matchesPossibleNull(JavaSignatureValues.stringBuilder, nullable = nullable)
+}
+
+fun IrType.isAnyAppendable(nullable: Boolean = false): Boolean {
+    return this.matchesPossibleNull(
+        getPublicSignature(StandardNames.TEXT_PACKAGE_FQ_NAME, "Appendable"),
+        nullable = nullable
+    ) || this.matchesPossibleNull(JavaSignatureValues.appendable, nullable = nullable)
 }