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Move builtin transform selection to game provider #1056

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Merged
merged 3 commits into from
Jul 2, 2025
Merged

Move builtin transform selection to game provider #1056

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d7b7da6
Move builtin transform selection to game provider
Player3324 Jun 22, 2025
e801471
Add trailing separator to classic and pre-classic package tests
Player3324 Jun 22, 2025
27166db
Add documentation, rename to WIDEN_ALL_PACKAGE_ACCESS
Player3324 Jun 22, 2025
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24 changes: 24 additions & 0 deletions minecraft/src/main/java/net/fabricmc/loader/impl/game/minecraft/MinecraftGameProvider.java
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Original file line number Diff line number Diff line change
Expand Up @@ -26,6 +26,7 @@
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.EnumSet;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
Expand Down Expand Up @@ -159,6 +160,29 @@ public boolean requiresUrlClassLoader() {
return hasModLoader;
}

@Override
public Set<BuiltinTransform> getBuiltinTransforms(String className) {
boolean isMinecraftClass = className.startsWith("net.minecraft.") // unobf classes in indev and later
|| className.startsWith("com.mojang.minecraft.") // unobf classes in classic
|| className.startsWith("com.mojang.rubydung.") // unobf classes in pre-classic
|| className.startsWith("com.mojang.blaze3d.") // unobf blaze3d classes
|| className.indexOf('.') < 0; // obf classes

if (isMinecraftClass) {
if (FabricLoaderImpl.INSTANCE.isDevelopmentEnvironment()) { // combined client+server jar, strip back down to production equivalent
return TRANSFORM_WIDENALL_STRIPENV_CLASSTWEAKS;
} else { // environment specific jar, inherently env stripped
return TRANSFORM_WIDENALL_CLASSTWEAKS;
}
} else { // mod class TODO: exclude game libs
return TRANSFORM_STRIPENV;
}
}

private static final Set<BuiltinTransform> TRANSFORM_WIDENALL_STRIPENV_CLASSTWEAKS = EnumSet.of(BuiltinTransform.WIDEN_ALL_PACKAGE_ACCESS, BuiltinTransform.STRIP_ENVIRONMENT, BuiltinTransform.CLASS_TWEAKS);
private static final Set<BuiltinTransform> TRANSFORM_WIDENALL_CLASSTWEAKS = EnumSet.of(BuiltinTransform.WIDEN_ALL_PACKAGE_ACCESS, BuiltinTransform.CLASS_TWEAKS);
private static final Set<BuiltinTransform> TRANSFORM_STRIPENV = EnumSet.of(BuiltinTransform.STRIP_ENVIRONMENT);

@Override
public boolean isEnabled() {
return System.getProperty(SystemProperties.SKIP_MC_PROVIDER) == null;
Expand Down
21 changes: 21 additions & 0 deletions src/main/java/net/fabricmc/loader/impl/game/GameProvider.java
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Expand Up @@ -20,12 +20,15 @@
import java.util.Collection;
import java.util.List;
import java.util.Objects;
import java.util.Set;

import net.fabricmc.api.Environment;
import net.fabricmc.loader.api.metadata.ModMetadata;
import net.fabricmc.loader.impl.game.patch.GameTransformer;
import net.fabricmc.loader.impl.launch.FabricLauncher;
import net.fabricmc.loader.impl.util.Arguments;
import net.fabricmc.loader.impl.util.LoaderUtil;
import net.fabricmc.loader.impl.util.SystemProperties;

public interface GameProvider { // name directly referenced in net.fabricmc.loader.impl.launch.knot.Knot.findEmbedddedGameProvider() and service loader records
String getGameId();
Expand All @@ -38,6 +41,24 @@ public interface GameProvider { // name directly referenced in net.fabricmc.load
Path getLaunchDirectory();
boolean isObfuscated();
boolean requiresUrlClassLoader();
Set<BuiltinTransform> getBuiltinTransforms(String className);
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Should we make this a default method for backwards compat? Other games couldn't use transforms previously so an empty set would make sense.

Doesn't really matter too much though.

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@Player3324 Player3324 Jun 22, 2025 •
edited
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I don't usually do this for internal interfaces like this, a custom GameProvider is probably better off with thinking about what the game actually wants.

We don't know what the right package for an arbitrary game would be and I haven't implemented tracking what a class is yet (game, game lib, mod, maybe more types).

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👍 makes sense.


enum BuiltinTransform {
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@Gamebuster19901 Gamebuster19901 Jun 22, 2025 •
edited
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I'm unfamiliar with these terms. Specifically STRIP_ENVIRONMENT and CLASS_TWEAKS. I looked in FabricTransformer but the usage isn't immediately clear to me. Perhaps we could add some documentation?

EDIT: I put this note in the wrong spot. It's for the enum values.

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I adjusted it, class tweakers is a bit of a future term for this branch, it's the new and eventually more powerful replacement for access wideners.

/**
* Removes classes, fields and methods annotated with a different {@literal @}{@link Environment} from the current runtime.
*/
STRIP_ENVIRONMENT,
/**
* Widens all package-internal access modifiers to public (protected and package-private, but not private).
*
* <p>This only has an effect if the mappings or {@link SystemProperties#FIX_PACKAGE_ACCESS} require these access modifications.
*/
WIDEN_ALL_PACKAGE_ACCESS,
/**
* Applies class tweakers, including access wideners, as supplied by mods.
*/
CLASS_TWEAKS,
}

boolean isEnabled();
boolean locateGame(FabricLauncher launcher, String[] args);
Expand Down
11 changes: 7 additions & 4 deletions src/main/java/net/fabricmc/loader/impl/transformer/FabricTransformer.java
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Original file line number Diff line number Diff line change
Expand Up @@ -16,21 +16,24 @@

package net.fabricmc.loader.impl.transformer;

import java.util.Set;

import org.objectweb.asm.ClassReader;
import org.objectweb.asm.ClassVisitor;
import org.objectweb.asm.ClassWriter;

import net.fabricmc.accesswidener.AccessWidenerClassVisitor;
import net.fabricmc.api.EnvType;
import net.fabricmc.loader.impl.FabricLoaderImpl;
import net.fabricmc.loader.impl.game.GameProvider.BuiltinTransform;
import net.fabricmc.loader.impl.launch.FabricLauncherBase;

public final class FabricTransformer {
public static byte[] transform(boolean isDevelopment, EnvType envType, String name, byte[] bytes) {
boolean isMinecraftClass = name.startsWith("net.minecraft.") || name.startsWith("com.mojang.blaze3d.") || name.indexOf('.') < 0;
boolean transformAccess = isMinecraftClass && FabricLauncherBase.getLauncher().getMappingConfiguration().requiresPackageAccessHack();
boolean environmentStrip = !isMinecraftClass || isDevelopment;
boolean applyAccessWidener = isMinecraftClass && FabricLoaderImpl.INSTANCE.getAccessWidener().getTargets().contains(name);
Set<BuiltinTransform> transforms = FabricLoaderImpl.INSTANCE.getGameProvider().getBuiltinTransforms(name);
boolean transformAccess = transforms.contains(BuiltinTransform.WIDEN_ALL_PACKAGE_ACCESS) && FabricLauncherBase.getLauncher().getMappingConfiguration().requiresPackageAccessHack();
boolean environmentStrip = transforms.contains(BuiltinTransform.STRIP_ENVIRONMENT);
boolean applyAccessWidener = transforms.contains(BuiltinTransform.CLASS_TWEAKS) && FabricLoaderImpl.INSTANCE.getAccessWidener().getTargets().contains(name);

if (!transformAccess && !environmentStrip && !applyAccessWidener) {
return bytes;
Expand Down