remapping overloaded field names (matching on field descriptor)

[agaricusb]

The JVM allows multiple fields to have the same name and owner but different descriptor:

http://docs.oracle.com/javase/specs/jvms/se7/html/jvms-4.html#jvms-4.5

Each field is described by a field_info structure. No two fields in one class file may have the same name and descriptor (§4.3.2).

Currently SpecialSource only supports remapping fields by (owner, name) -> name, not (owner, name, desc) -> name. This normally suffices since Java source code cannot overload fields, but, obfuscation can introduce this unusual but valid bytecode. To deobfuscate properly, the field type descriptors are needed in the mappings (should be optional).

See also: MinecraftForge/FML#210

[tonybruess]

👍 This happened when I did my CraftBukkit update

[agaricusb]

@mrapple hm are you sure, what specific symbols were problematic? I've only seen this when deobfuscating obfuscated CB, AFAIK it only occurs when a subclass references a field from its superclass which was private in vanilla but was edited for greater visibility and the obfuscated name happens to collide with another field in a subclass (specific example in FML issue 210, but could also occur with coremods using access transformers).

[tonybruess]

Can't remember exactly, but it's the case you describe. A field that was edited in a superclass.

[agaricusb]

FWIW, FML now includes this feature, for its runtime deobfuscation (the field type info is looked up dynamically).

[agaricusb]

Overloaded field in 1.5.2 (noted while debugging MCPC+):

FD: net/minecraft/entity/EntityLiving/potionsNeedUpdate net/minecraft/entity/EntityLiving/field_70752_e
FD: net/minecraft/entity/player/EntityPlayerMP/playerInventoryBeingManipulated net/minecraft/entity/player/EntityPlayerMP/field_71137_h

FD: net/minecraft/entity/player/EntityPlayerMP/playerInventoryBeingManipulated jc/h
FD: net/minecraft/entity/EntityLiving/potionsNeedUpdate ng/h

[agaricusb]

MinecraftPortCentral/Cauldron@e447c52

[tonybruess]

Also, this occurred again during the 1.6 update. How do we fix this?

[tonybruess]

Does this relate to #3? When it's fixed will this be fixed?