From 5ed46ac9657a2f94e7a70e3c62c6b5c6fc093bba Mon Sep 17 00:00:00 2001
From: Ramid Khan <ramidzkh@gmail.com>
Date: Sat, 3 Oct 2020 06:32:19 +1000
Subject: [PATCH 1/2] Automatically propose field Codec names

---
 .../fabricmc/stitch/util/FieldNameFinder.java | 24 +++++++++++++++++++
 1 file changed, 24 insertions(+)

diff --git a/src/main/java/net/fabricmc/stitch/util/FieldNameFinder.java b/src/main/java/net/fabricmc/stitch/util/FieldNameFinder.java
index 8e3ef6d..eb5f3e9 100644
--- a/src/main/java/net/fabricmc/stitch/util/FieldNameFinder.java
+++ b/src/main/java/net/fabricmc/stitch/util/FieldNameFinder.java
@@ -155,6 +155,30 @@ public Map<EntryTriple, String> findNames(Map<String, Set<String>> allEnumFields
 			}
 		}
 
+		// For Codecs
+		for (Map.Entry<String, List<MethodNode>> entry : classes.entrySet()) {
+			String owner = entry.getKey();
+
+			for (MethodNode node : entry.getValue()) {
+				// Codecs should be set in class initialization
+				if ("<clinit>".equals(node.name)) {
+					for (AbstractInsnNode instruction : node.instructions) {
+						// Look for PUTSTATIC instructions
+						if (instruction instanceof FieldInsnNode
+								&& instruction.getOpcode() == Opcodes.PUTSTATIC) {
+							FieldInsnNode fieldInsnNode = (FieldInsnNode) instruction;
+
+							// Find PUTSTATIC which set to this class and use Codec as their descriptor
+							if (owner.equals(fieldInsnNode.owner)
+									&& fieldInsnNode.desc.equals("Lcom/mojang/serialization/Codec;")) {
+								fieldNames.put(new EntryTriple(owner, fieldInsnNode.name, fieldInsnNode.desc), "CODEC");
+							}
+						}
+					}
+				}
+			}
+		}
+
 		return fieldNames;
 	}
 

From e08aed5b28f2d58a5286467a8c7b4cd7b410a96b Mon Sep 17 00:00:00 2001
From: Ramid Khan <ramidzkh@gmail.com>
Date: Sat, 3 Oct 2020 06:57:48 +1000
Subject: [PATCH 2/2] Don't duplicate names

---
 .../fabricmc/stitch/util/FieldNameFinder.java   | 17 ++++++++++++++++-
 1 file changed, 16 insertions(+), 1 deletion(-)

diff --git a/src/main/java/net/fabricmc/stitch/util/FieldNameFinder.java b/src/main/java/net/fabricmc/stitch/util/FieldNameFinder.java
index eb5f3e9..24165cc 100644
--- a/src/main/java/net/fabricmc/stitch/util/FieldNameFinder.java
+++ b/src/main/java/net/fabricmc/stitch/util/FieldNameFinder.java
@@ -160,6 +160,8 @@ public Map<EntryTriple, String> findNames(Map<String, Set<String>> allEnumFields
 			String owner = entry.getKey();
 
 			for (MethodNode node : entry.getValue()) {
+				List<String> names = new ArrayList<>();
+
 				// Codecs should be set in class initialization
 				if ("<clinit>".equals(node.name)) {
 					for (AbstractInsnNode instruction : node.instructions) {
@@ -171,11 +173,24 @@ public Map<EntryTriple, String> findNames(Map<String, Set<String>> allEnumFields
 							// Find PUTSTATIC which set to this class and use Codec as their descriptor
 							if (owner.equals(fieldInsnNode.owner)
 									&& fieldInsnNode.desc.equals("Lcom/mojang/serialization/Codec;")) {
-								fieldNames.put(new EntryTriple(owner, fieldInsnNode.name, fieldInsnNode.desc), "CODEC");
+								names.add(fieldInsnNode.name);
 							}
 						}
 					}
 				}
+
+				if (names.isEmpty()) {
+					// Nothing was found
+					continue;
+				}
+
+				if (names.size() == 1 && !fieldNamesUsed.computeIfAbsent(owner, (s) -> new HashSet<>()).contains("CODEC")) {
+					// No duplicates were found
+					fieldNames.put(new EntryTriple(owner, names.get(0), "Lcom/mojang/serialization/Codec;"), "CODEC");
+					continue;
+				}
+
+				System.err.println("Warning: Duplicate key: CODEC in " + owner);
 			}
 		}