Allowing injecting in constructor

build.gradle

@@ -156,6 +156,7 @@ dependencies {
     modlauncherCompile ('cpw.mods:modlauncher:4.2.0') {
         exclude module: 'log4j-core'
     }
+    modlauncherImplementation 'cpw.mods:grossjava9hacks:1.3.+'
 
     // agent
     agentCompile configurations.compile

src/main/java/org/spongepowered/asm/mixin/injection/InjectionPoint.java

@@ -266,6 +266,18 @@ public boolean checkPriority(int targetPriority, int mixinPriority) {
      * @return restriction level
      */
     public RestrictTargetLevel getTargetRestriction(IInjectionPointContext context) {
+        return RestrictTargetLevel.CONSTRUCTORS_AFTER_DELEGATE;
+    }
+
+    /**
+     * Returns the target restriction level for this injection point's cancellation for
+     * {@literal @Inject} annotations. This level defines whether an injection point
+     * can declare {@code cancellable = true}.
+     *
+     * @param context injection-specific context
+     * @return restriction level
+     */
+    public RestrictTargetLevel getCancellationRestriction(IInjectionPointContext context) {
         return RestrictTargetLevel.METHODS_ONLY;
     }
 

src/main/java/org/spongepowered/asm/mixin/injection/callback/CallbackInjector.java

@@ -397,6 +397,14 @@ protected void addTargetNode(Target target, List<InjectionNode> myNodes, Abstrac
                 throw new InvalidInjectionException(this.info, String.format("%s selector %s", ip, ex.getMessage()));
             }
 
+            if (this.cancellable) {
+                try {
+                    this.checkTargetForNode(target, injectionNode, ip.getCancellationRestriction(this.info));
+                } catch (InvalidInjectionException ex) {
+                    throw new InvalidInjectionException(this.info, String.format("%s selector (cancellable = true) %s", ip, ex.getMessage()));
+                }
+            }
+
             String id = ip.getId();
             if (Strings.isNullOrEmpty(id)) {
                 continue;