Fix indices of method parameters when using tsrg files

api/src/main/java/net/neoforged/jst/api/PsiHelper.java

@@ -184,7 +184,7 @@ private static boolean isNonStaticInnerClassConstructor(PsiMethod method) {
         return false;
     }
 
-    private static boolean isNonStaticInnerClass(PsiClass psiClass) {
+    public static boolean isNonStaticInnerClass(PsiClass psiClass) {
         return psiClass.getContainingClass() != null && !psiClass.hasModifierProperty(PsiModifier.STATIC);
     }
 

parchment/src/main/java/net/neoforged/jst/parchment/GatherReplacementsVisitor.java

@@ -104,6 +104,19 @@ public void visitElement(@NotNull PsiElement element) {
                 var parameters = psiMethod.getParameterList().getParameters();
                 var parametersLvtIndices = PsiHelper.getParameterLvtIndices(psiMethod);
                 boolean hadReplacements = false;
+
+                int parameterOffset = 0;
+                if (psiMethod.isConstructor()) {
+                    // Enums offset the parameter index by 2 since they add an int and a string param which are not visible in the source
+                    if (psiMethod.getContainingClass().isEnum()) {
+                        parameterOffset = 2;
+                    }
+                    // Non-static inner classes capture their owner as the first parameter
+                    else if (PsiHelper.isNonStaticInnerClass(psiMethod.getContainingClass())) {
+                        parameterOffset = 1;
+                    }
+                }
+
                 for (int i = 0; i < parameters.length; i++) {
                     var psiParameter = parameters[i];
                     // We cannot replace parameters with no name, sadly
@@ -115,7 +128,7 @@ public void visitElement(@NotNull PsiElement element) {
                     // to account for synthetic parameter not found in the source-code, we must adjust the index accordingly.
                     var jvmIndex = parametersLvtIndices[i];
 
-                    var paramData = methodData.getParameter(jvmIndex);
+                    var paramData = methodData.getParameter(parameterOffset + i, jvmIndex);
                     // Optionally replace the parameter name, but skip record constructors, since those could have
                     // implications for the field names.
                     if (paramData != null && paramData.getName() != null && !PsiHelper.isRecordConstructor(psiMethod)) {

parchment/src/main/java/net/neoforged/jst/parchment/namesanddocs/NamesAndDocsForMethod.java

@@ -5,5 +5,5 @@
 public interface NamesAndDocsForMethod {
     List<String> getJavadoc();
 
-    NamesAndDocsForParameter getParameter(int index);
+    NamesAndDocsForParameter getParameter(int index, int jvmIndex);
 }

parchment/src/main/java/net/neoforged/jst/parchment/namesanddocs/parchment/ParchmentNamesAndDocsForMethod.java

@@ -19,8 +19,8 @@ public List<String> getJavadoc() {
     }
 
     @Override
-    public NamesAndDocsForParameter getParameter(int index) {
-        var paramData = methodData.getParameter((byte) index);
+    public NamesAndDocsForParameter getParameter(int index, int jvmIndex) {
+        var paramData = methodData.getParameter((byte) jvmIndex);
         return paramData != null ? new ParchmentNamesAndDocsForParameter(paramData) : null;
     }
 }

parchment/src/main/java/net/neoforged/jst/parchment/namesanddocs/srgutils/MappingFileMethodData.java

@@ -20,7 +20,7 @@ public List<String> getJavadoc() {
     }
 
     @Override
-    public NamesAndDocsForParameter getParameter(int index) {
+    public NamesAndDocsForParameter getParameter(int index, int jvmIndex) {
         var paramData = methodData.getParameter(index);
         if (paramData == null || paramData.getMapped() == null) {
             return null;

tests/data/parchment/tsrg_file/expected/pkg/TestClass.java

@@ -5,4 +5,16 @@
 public class TestClass {
     public void m(String p_254545_, List<String> p_254546_) {
     }
+
+    public class Inner {
+        public Inner(int p_298711_) {
+
+        }
+    }
+
+    public enum Enm {
+        ;
+
+        Enm(boolean p_123452_) {}
+    }
 }

tests/data/parchment/tsrg_file/merged.tsrg

@@ -1,5 +1,14 @@
 tsrg2 left right
 obfuscated_c pkg/TestClass
 	obfuscated_m (Ljava/lang/String;Ljava/util/List;)V m
-		1 o p_254545_
-		2 o p_254546_
+		0 o p_254545_
+		1 o p_254546_
+obfuscated_c$i pkg/TestClass$Inner
+	<init> (Lpkg/TestClass;I)V <init>
+		0 o p_298710_
+		1 o p_298711_
+obfuscated_c$e pkg/TestClass$Enm
+	<init> (Ljava/lang/String;IZ)V <init>
+		0 o p_123450_
+		1 o p_123451_
+		2 o p_123452_

tests/data/parchment/tsrg_file/source/pkg/TestClass.java

@@ -5,4 +5,16 @@
 public class TestClass {
     public void m(String a1, List<String> a2) {
     }
+
+    public class Inner {
+        public Inner(int a1) {
+
+        }
+    }
+
+    public enum Enm {
+        ;
+
+        Enm(boolean a3) {}
+    }
 }