fabric/fabric-transitive-access-wideners-v1/build.gradle

archivesBaseName = "fabric-transitive-access-wideners-v1"
version = getSubprojectVersion(project)

loom {
	accessWidenerPath = file('src/main/resources/fabric-transitive-access-wideners-v1.accesswidener')
}

import org.objectweb.asm.ClassReader
import org.objectweb.asm.Opcodes
import org.objectweb.asm.Type
import org.objectweb.asm.tree.ClassNode

import java.nio.file.FileSystem
import java.nio.file.FileSystems
import java.nio.file.Files
import java.nio.file.Path
import java.util.stream.Collectors

task generateAccessWidener {
	doLast {
		List<String> lines = file("template.accesswidener").text.lines().collect(Collectors.toCollection { [] })
		Path inputJar = loom.namedMinecraftProvider.parentMinecraftProvider.mergedJar

		try (def fs = FileSystems.newFileSystem(URI.create("jar:${inputJar.toUri()}"), [create: false])) {
			generateBlockConstructors(lines, fs)
		}

		file('src/main/resources/fabric-transitive-access-wideners-v1.accesswidener').text = String.join('\n', lines) + '\n'
	}
}

def generateBlockConstructors(List<String> lines, FileSystem fs) {
	lines.add("# Constructors of non-abstract block classes")
	Files.list(fs.getPath("net/minecraft/block"))
		.filter { Files.isRegularFile(it) && it.toString().endsWith(".class") }
		.map { loadClass(it) }
		.sorted(Comparator.comparing { it.name })
		.filter { (it.access & Opcodes.ACC_ABSTRACT) == 0 }
		.forEach { node ->
			for (def method : node.methods) {
				// Checklist for finding block constructors as of 1.18.2:
				//  - class directly in net.minecraft.block (excluding subpackages)
				//  - method name == <init> (by definition)
				//  - contains an AbstractBlock$Settings parameter
				//  - only taking into account non-abstract classes and non-public constructors

				// Block constructor...
				if (method.name == "<init>" && Type.getArgumentTypes(method.desc).any { it.internalName == 'net/minecraft/block/AbstractBlock$Settings' }) {
					// ...and non-public
					if ((method.access & Opcodes.ACC_PUBLIC) == 0) {
						lines.add("transitive-accessible method $node.name <init> $method.desc")
					}
				}
			}
		}
}

ClassNode loadClass(Path path) {
	def node = new ClassNode()

	try (def is = Files.newInputStream(path)) {
		new ClassReader(is).accept(node, ClassReader.SKIP_CODE | ClassReader.SKIP_DEBUG | ClassReader.SKIP_FRAMES)
	}

	return node
}

generateResources.dependsOn generateAccessWidener