[WASM] Avoid triggering clinit from internal calls in class

This handles basic inner cycles for clinit due to calls to methods.

Consider following:

```
class Foo {
   // initialized in Foo.clinit
   public static final Foo instance = new Foo();

   // Also calls Foo.clinit since it is public
   public Foo() {}
}
```

We essentially have two entry points in the classes that we need to clinit. This introduces a cycle in clinit (clinit call ctor, ctor calls clinit) and we cannot hoist instance to global because it is no longer trivial.

This could also happen with following pattern:

```
class Foo {
   // initialized in Foo.clinit
   public static final int instance = someHelper();

   // Also calls Foo.clinit since it is public
   public static int someHelper() { ... }
}
```

To overcome this problem, when there is a public method that triggers clinit, we can make it private and add a public one that calls clinit. Then re-writing Internal calls go through private one so they don't trigger clinit. Since this only requires local knowledge, it is compatible with modular compilation.

PiperOrigin-RevId: 590882728

transpiler/java/com/google/j2cl/transpiler/ast/AstUtils.java

@@ -194,8 +194,6 @@ private static Method createForwardingMethod(
       MethodDescriptor toMethodDescriptor,
       String jsDocDescription,
       boolean isStaticDispatch) {
-    checkArgument(!fromMethodDescriptor.getEnclosingTypeDescriptor().isInterface());
-
     List<Variable> parameters =
         createParameterVariables(fromMethodDescriptor.getParameterTypeDescriptors());
 

transpiler/java/com/google/j2cl/transpiler/passes/ImplementStaticInitializationBase.java

@@ -48,7 +48,6 @@ public final void applyTo(CompilationUnit compilationUnit) {
       if (type.isNative()) {
         continue;
       }
-      synthesizeClinitCallsInMethods(type);
       synthesizeSuperClinitCalls(type);
       // Apply the additional normalizations defined in subclasses.
       applyTo(type);
@@ -87,7 +86,7 @@ private static String getUniqueIdentifier(MemberDescriptor memberDescriptor) {
   }
 
   /** Add clinit calls to methods and (real js) constructors. */
-  private void synthesizeClinitCallsInMethods(Type type) {
+  public void synthesizeClinitCallsInMethods(Type type) {
     type.accept(
         new AbstractRewriter() {
           @Override

transpiler/java/com/google/j2cl/transpiler/passes/ImplementStaticInitializationViaClinitFunctionRedirection.java

@@ -57,6 +57,7 @@ public void applyTo(Type type) {
     if (type.isJsEnum()) {
       return;
     }
+    synthesizeClinitCallsInMethods(type);
     synthesizeSettersAndGetters(type);
     synthesizeClinitMethod(type);
     synthesizeStaticFieldDeclaration(type);

transpiler/java/com/google/j2cl/transpiler/passes/ImplementStaticInitializationViaConditionChecks.java

@@ -15,10 +15,12 @@
  */
 package com.google.j2cl.transpiler.passes;
 
+import static com.google.common.base.Preconditions.checkState;
 import static com.google.common.collect.ImmutableList.toImmutableList;
 
 import com.google.j2cl.common.SourcePosition;
 import com.google.j2cl.transpiler.ast.AbstractRewriter;
+import com.google.j2cl.transpiler.ast.AstUtils;
 import com.google.j2cl.transpiler.ast.BinaryExpression;
 import com.google.j2cl.transpiler.ast.BooleanLiteral;
 import com.google.j2cl.transpiler.ast.DeclaredTypeDescriptor;
@@ -27,12 +29,17 @@
 import com.google.j2cl.transpiler.ast.FieldAccess;
 import com.google.j2cl.transpiler.ast.FieldDescriptor;
 import com.google.j2cl.transpiler.ast.IfStatement;
+import com.google.j2cl.transpiler.ast.Member;
 import com.google.j2cl.transpiler.ast.Method;
+import com.google.j2cl.transpiler.ast.MethodCall;
+import com.google.j2cl.transpiler.ast.MethodDescriptor;
 import com.google.j2cl.transpiler.ast.MultiExpression;
 import com.google.j2cl.transpiler.ast.PrimitiveTypes;
 import com.google.j2cl.transpiler.ast.ReturnStatement;
 import com.google.j2cl.transpiler.ast.Statement;
 import com.google.j2cl.transpiler.ast.Type;
+import com.google.j2cl.transpiler.ast.Visibility;
+import java.util.HashMap;
 import java.util.List;
 
 /**
@@ -46,13 +53,35 @@ public class ImplementStaticInitializationViaConditionChecks
   @Override
   public void applyTo(Type type) {
     synthesizeClinitCallsOnFieldAccess(type);
+    synthesizeClinitCallsInMethods(type);
     synthesizeClinitMethod(type);
   }
 
   /** Add clinit calls to field accesses. */
   private void synthesizeClinitCallsOnFieldAccess(Type type) {
+    HashMap<MethodDescriptor, MethodDescriptor> neededPrivateMethodsByPublic = new HashMap<>();
     type.accept(
         new AbstractRewriter() {
+          @Override
+          public Expression rewriteMethodCall(MethodCall methodCall) {
+            // To avoid calling clinit when calling the methods on the same class, the non-private
+            // method is converted to private method call. Then later on (below) we will add these
+            // new private methods.
+
+            MethodDescriptor target = methodCall.getTarget();
+            if (target.isMemberOf(type.getDeclaration()) && triggersClinit(target, type)) {
+              checkState(target.isStatic());
+
+              // No need to call clinit when accessing the method from members in the enclosing
+              // type.
+              MethodDescriptor privateDescriptor = createPrivateDescriptor(target);
+              methodCall = MethodCall.Builder.from(methodCall).setTarget(privateDescriptor).build();
+              neededPrivateMethodsByPublic.put(
+                  target.getDeclarationDescriptor(), privateDescriptor.getDeclarationDescriptor());
+            }
+            return methodCall;
+          }
+
           @Override
           public Expression rewriteFieldAccess(FieldAccess fieldAccess) {
             FieldDescriptor target = fieldAccess.getTarget();
@@ -75,6 +104,35 @@ public Expression rewriteFieldAccess(FieldAccess fieldAccess) {
             return fieldAccess;
           }
         });
+
+    // Insert private methods needed and make the public ones bridge to them to trigger clinit.
+    List<Member> members = type.getMembers();
+    for (int i = 0; i < members.size(); i++) {
+      if (!members.get(i).isMethod()) {
+        continue;
+      }
+      Method method = (Method) members.get(i);
+      MethodDescriptor privateDescriptor =
+          neededPrivateMethodsByPublic.remove(method.getDescriptor());
+      if (privateDescriptor == null) {
+        continue;
+      }
+      Method newPublicMethod =
+          AstUtils.createForwardingMethod(
+              method.getSourcePosition(),
+              null,
+              method.getDescriptor(),
+              privateDescriptor,
+              "Bridge to private");
+      members.set(i, newPublicMethod);
+      members.add(++i, Method.Builder.from(method).setMethodDescriptor(privateDescriptor).build());
+    }
+    checkState(neededPrivateMethodsByPublic.isEmpty(), neededPrivateMethodsByPublic);
+  }
+
+  private static MethodDescriptor createPrivateDescriptor(MethodDescriptor descriptor) {
+    return descriptor.transform(
+        m -> m.setVisibility(Visibility.PRIVATE).setName(descriptor.getName() + "_$private"));
   }
 
   /** Implements the static initialization method ($clinit). */

transpiler/javatests/com/google/j2cl/readable/java/bridgemethods/output_wasm/module.wat.txt

@@ -4969,10 +4969,20 @@
 (func [email protected]
  (result (ref null $bridgemethods.AccidentalOverrideBridge))
  ;;@ bridgemethods/BridgeMethod.java:96:6
- (local $$instance (ref null $bridgemethods.AccidentalOverrideBridge))
  (block
   ;;@ bridgemethods/BridgeMethod.java:96:6
   (call $$clinit__void_<once>[email protected] )
+  ;;@ bridgemethods/BridgeMethod.java:96:6
+  (return (call [email protected] ))
+ )
+)
+
+;;; AccidentalOverrideBridge AccidentalOverrideBridge.$create_$private()
+(func [email protected]
+ (result (ref null $bridgemethods.AccidentalOverrideBridge))
+ ;;@ bridgemethods/BridgeMethod.java:96:6
+ (local $$instance (ref null $bridgemethods.AccidentalOverrideBridge))
+ (block
   ;;@ bridgemethods/BridgeMethod.java:96:6
   (local.set $$instance (struct.new $bridgemethods.AccidentalOverrideBridge (ref.as_non_null (global.get $bridgemethods.AccidentalOverrideBridge.vtable)) (ref.as_non_null (global.get $bridgemethods.AccidentalOverrideBridge.itable)) (i32.const 0)))
   ;;@ bridgemethods/BridgeMethod.java:96:6
@@ -5002,7 +5012,7 @@
  (local.set $this (ref.cast (ref $bridgemethods.AccidentalOverrideBridge) (local.get $this.untyped)))
  (block
   ;;@ bridgemethods/BridgeMethod.java:100:4
-  (local.set $g (call $$create__@bridgemethods.AccidentalOverrideBridge ))
+  (local.set $g (call $$create_$private__@bridgemethods.AccidentalOverrideBridge ))
   ;;@ bridgemethods/BridgeMethod.java:101:4
   (drop (call_ref $function.m_get__java_lang_String__java_lang_String (ref.as_non_null (local.get $g))(call $function.no.side.effects.$getString_||__java_lang_String (ref.func $$getString_||[email protected]) )(struct.get $bridgemethods.Getter.vtable $m_get__java_lang_String__java_lang_String (ref.cast (ref $bridgemethods.Getter.vtable) (struct.get $itable $slot0 (struct.get $java.lang.Object $itable (local.get $g)))))))
  )

transpiler/javatests/com/google/j2cl/readable/java/cast/output_wasm/module.wat.txt

@@ -793,10 +793,20 @@
 (func [email protected]
  (result (ref null $cast.CastGenerics))
  ;;@ cast/CastGenerics.java:20:13
- (local $$instance (ref null $cast.CastGenerics))
  (block
   ;;@ cast/CastGenerics.java:20:13
   (call $$clinit__void_<once>[email protected] )
+  ;;@ cast/CastGenerics.java:20:13
+  (return (call [email protected] ))
+ )
+)
+
+;;; CastGenerics<T, E> CastGenerics.$create_$private()
+(func [email protected]
+ (result (ref null $cast.CastGenerics))
+ ;;@ cast/CastGenerics.java:20:13
+ (local $$instance (ref null $cast.CastGenerics))
+ (block
   ;;@ cast/CastGenerics.java:20:13
   (local.set $$instance (struct.new $cast.CastGenerics (ref.as_non_null (global.get $cast.CastGenerics.vtable)) (ref.as_non_null (global.get $itable.empty)) (i32.const 0) (ref.null $java.lang.Object)))
   ;;@ cast/CastGenerics.java:20:13
@@ -862,10 +872,10 @@
   ;;@ cast/CastGenerics.java:50:70
   (call $$clinit__void_<once>[email protected] )
   ;;@ cast/CastGenerics.java:51:4
-  (local.set $str (ref.cast (ref null $java.lang.String) (struct.get $cast.CastGenerics [email protected] (call $$create__@cast.CastGenerics ))))
+  (local.set $str (ref.cast (ref null $java.lang.String) (struct.get $cast.CastGenerics [email protected] (call $$create_$private__@cast.CastGenerics ))))
   ;;@ cast/CastGenerics.java:52:4
   (local.set $str (ref.cast (ref null $java.lang.String) (block (result (ref null $java.lang.Object))
-   (local.set $$qualifier (call $$create__@cast.CastGenerics ))
+   (local.set $$qualifier (call $$create_$private__@cast.CastGenerics ))
    (call_ref $function.m_method__java_lang_Object_$pp_cast (ref.as_non_null (local.get $$qualifier))(struct.get $cast.CastGenerics.vtable $m_method__java_lang_Object_$pp_cast (struct.get $cast.CastGenerics $vtable(local.get $$qualifier))))
   )))
   ;;@ cast/CastGenerics.java:54:4

transpiler/javatests/com/google/j2cl/readable/java/castonarrayinit/output_wasm/module.wat.txt

@@ -103,13 +103,23 @@
  )
 )
 
-;;; void CastOnArrayInit.fun(Foo<E>... args)
+;;; void CastOnArrayInit.fun(Foo<E>... arg0)
 (func $m_fun__arrayOf_castonarrayinit_CastOnArrayInit_Foo__void@castonarrayinit.CastOnArrayInit
- (param $args (ref null $javaemul.internal.WasmArray.OfObject))
+ (param $arg0 (ref null $javaemul.internal.WasmArray.OfObject))
  ;;@ castonarrayinit/CastOnArrayInit.java:21:25
  (block
-  ;;@ castonarrayinit/CastOnArrayInit.java:21:45
+  ;;@ castonarrayinit/CastOnArrayInit.java:21:25
   (call $$clinit__void_<once>[email protected] )
+  ;;@ castonarrayinit/CastOnArrayInit.java:21:25
+  (call $m_fun_$private__arrayOf_castonarrayinit_CastOnArrayInit_Foo__void@castonarrayinit.CastOnArrayInit (local.get $arg0))
+ )
+)
+
+;;; void CastOnArrayInit.fun_$private(Foo<E>... args)
+(func $m_fun_$private__arrayOf_castonarrayinit_CastOnArrayInit_Foo__void@castonarrayinit.CastOnArrayInit
+ (param $args (ref null $javaemul.internal.WasmArray.OfObject))
+ ;;@ castonarrayinit/CastOnArrayInit.java:21:25
+ (block
  )
 )
 
@@ -126,7 +136,7 @@
   ;;@ castonarrayinit/CastOnArrayInit.java:25:4
   (local.set $f2 (call [email protected] ))
   ;;@ castonarrayinit/CastOnArrayInit.java:26:4
-  (call $m_fun__arrayOf_castonarrayinit_CastOnArrayInit_Foo__void@castonarrayinit.CastOnArrayInit (call $m_newWithLiteral__arrayOf_java_lang_Object__javaemul_internal_WasmArray_OfObject@javaemul.internal.WasmArray.OfObject (array.new_fixed $java.lang.Object.array (local.get $f1)(local.get $f2))))
+  (call $m_fun_$private__arrayOf_castonarrayinit_CastOnArrayInit_Foo__void@castonarrayinit.CastOnArrayInit (call $m_newWithLiteral__arrayOf_java_lang_Object__javaemul_internal_WasmArray_OfObject@javaemul.internal.WasmArray.OfObject (array.new_fixed $java.lang.Object.array (local.get $f1)(local.get $f2))))
  )
 )
 

transpiler/javatests/com/google/j2cl/readable/java/cloneable/output_wasm/module.wat.txt

@@ -342,10 +342,20 @@
 (func [email protected]
  (result (ref null $cloneable.Cloneables.WithoutCloneable))
  ;;@ cloneable/Cloneables.java:19:22
- (local $$instance (ref null $cloneable.Cloneables.WithoutCloneable))
  (block
   ;;@ cloneable/Cloneables.java:19:22
   (call $$clinit__void_<once>[email protected] )
+  ;;@ cloneable/Cloneables.java:19:22
+  (return (call [email protected] ))
+ )
+)
+
+;;; WithoutCloneable WithoutCloneable.$create_$private()
+(func [email protected]
+ (result (ref null $cloneable.Cloneables.WithoutCloneable))
+ ;;@ cloneable/Cloneables.java:19:22
+ (local $$instance (ref null $cloneable.Cloneables.WithoutCloneable))
+ (block
   ;;@ cloneable/Cloneables.java:19:22
   (local.set $$instance (struct.new $cloneable.Cloneables.WithoutCloneable (ref.as_non_null (global.get $cloneable.Cloneables.WithoutCloneable.vtable)) (ref.as_non_null (global.get $itable.empty)) (i32.const 0)))
   ;;@ cloneable/Cloneables.java:19:22
@@ -375,7 +385,7 @@
  (local.set $this (ref.cast (ref $cloneable.Cloneables.WithoutCloneable) (local.get $this.untyped)))
  (block
   ;;@ cloneable/Cloneables.java:23:6
-  (return (call $$create__@cloneable.Cloneables.WithoutCloneable ))
+  (return (call $$create_$private__@cloneable.Cloneables.WithoutCloneable ))
  )
 )
 (elem declare func [email protected])
@@ -443,10 +453,20 @@
 (func [email protected]
  (result (ref null $cloneable.Cloneables.WithCloneable))
  ;;@ cloneable/Cloneables.java:27:22
- (local $$instance (ref null $cloneable.Cloneables.WithCloneable))
  (block
   ;;@ cloneable/Cloneables.java:27:22
   (call $$clinit__void_<once>[email protected] )
+  ;;@ cloneable/Cloneables.java:27:22
+  (return (call [email protected] ))
+ )
+)
+
+;;; WithCloneable WithCloneable.$create_$private()
+(func [email protected]
+ (result (ref null $cloneable.Cloneables.WithCloneable))
+ ;;@ cloneable/Cloneables.java:27:22
+ (local $$instance (ref null $cloneable.Cloneables.WithCloneable))
+ (block
   ;;@ cloneable/Cloneables.java:27:22
   (local.set $$instance (struct.new $cloneable.Cloneables.WithCloneable (ref.as_non_null (global.get $cloneable.Cloneables.WithCloneable.vtable)) (ref.as_non_null (global.get $cloneable.Cloneables.WithCloneable.itable)) (i32.const 0)))
   ;;@ cloneable/Cloneables.java:27:22
@@ -476,7 +496,7 @@
  (local.set $this (ref.cast (ref $cloneable.Cloneables.WithCloneable) (local.get $this.untyped)))
  (block
   ;;@ cloneable/Cloneables.java:31:6
-  (return (call $$create__@cloneable.Cloneables.WithCloneable ))
+  (return (call $$create_$private__@cloneable.Cloneables.WithCloneable ))
  )
 )
 (elem declare func [email protected])
@@ -544,10 +564,20 @@
 (func [email protected]
  (result (ref null $cloneable.Cloneables.WithoutCloneableChild))
  ;;@ cloneable/Cloneables.java:35:28
- (local $$instance (ref null $cloneable.Cloneables.WithoutCloneableChild))
  (block
   ;;@ cloneable/Cloneables.java:35:28
   (call $$clinit__void_<once>[email protected] )
+  ;;@ cloneable/Cloneables.java:35:28
+  (return (call [email protected] ))
+ )
+)
+
+;;; WithoutCloneableChild WithoutCloneableChild.$create_$private()
+(func [email protected]
+ (result (ref null $cloneable.Cloneables.WithoutCloneableChild))
+ ;;@ cloneable/Cloneables.java:35:28
+ (local $$instance (ref null $cloneable.Cloneables.WithoutCloneableChild))
+ (block
   ;;@ cloneable/Cloneables.java:35:28
   (local.set $$instance (struct.new $cloneable.Cloneables.WithoutCloneableChild (ref.as_non_null (global.get $cloneable.Cloneables.WithoutCloneableChild.vtable)) (ref.as_non_null (global.get $itable.empty)) (i32.const 0)))
   ;;@ cloneable/Cloneables.java:35:28
@@ -577,7 +607,7 @@
  (local.set $this (ref.cast (ref $cloneable.Cloneables.WithoutCloneableChild) (local.get $this.untyped)))
  (block
   ;;@ cloneable/Cloneables.java:38:6
-  (return (call $$create__@cloneable.Cloneables.WithoutCloneableChild ))
+  (return (call $$create_$private__@cloneable.Cloneables.WithoutCloneableChild ))
  )
 )
 (elem declare func $m_clone__java_lang_Object@cloneable.Cloneables.WithoutCloneableChild)
@@ -645,10 +675,20 @@
 (func [email protected]
  (result (ref null $cloneable.Cloneables.WithCloneableChild))
  ;;@ cloneable/Cloneables.java:42:28
- (local $$instance (ref null $cloneable.Cloneables.WithCloneableChild))
  (block
   ;;@ cloneable/Cloneables.java:42:28
   (call $$clinit__void_<once>[email protected] )
+  ;;@ cloneable/Cloneables.java:42:28
+  (return (call [email protected] ))
+ )
+)
+
+;;; WithCloneableChild WithCloneableChild.$create_$private()
+(func [email protected]
+ (result (ref null $cloneable.Cloneables.WithCloneableChild))
+ ;;@ cloneable/Cloneables.java:42:28
+ (local $$instance (ref null $cloneable.Cloneables.WithCloneableChild))
+ (block
   ;;@ cloneable/Cloneables.java:42:28
   (local.set $$instance (struct.new $cloneable.Cloneables.WithCloneableChild (ref.as_non_null (global.get $cloneable.Cloneables.WithCloneableChild.vtable)) (ref.as_non_null (global.get $cloneable.Cloneables.WithCloneableChild.itable)) (i32.const 0)))
   ;;@ cloneable/Cloneables.java:42:28
@@ -678,7 +718,7 @@
  (local.set $this (ref.cast (ref $cloneable.Cloneables.WithCloneableChild) (local.get $this.untyped)))
  (block
   ;;@ cloneable/Cloneables.java:45:6
-  (return (call $$create__@cloneable.Cloneables.WithCloneableChild ))
+  (return (call $$create_$private__@cloneable.Cloneables.WithCloneableChild ))
  )
 )
 (elem declare func $m_clone__java_lang_Object@cloneable.Cloneables.WithCloneableChild)

transpiler/javatests/com/google/j2cl/readable/java/collisions/output_wasm/module.wat.txt

@@ -865,10 +865,20 @@
 (func [email protected]
  (result (ref null $collisions.T))
  ;;@ collisions/goog.java:74:6
- (local $$instance (ref null $collisions.T))
  (block
   ;;@ collisions/goog.java:74:6
   (call $$clinit__void_<once>[email protected] )
+  ;;@ collisions/goog.java:74:6
+  (return (call [email protected] ))
+ )
+)
+
+;;; T<T> T.$create_$private()
+(func [email protected]
+ (result (ref null $collisions.T))
+ ;;@ collisions/goog.java:74:6
+ (local $$instance (ref null $collisions.T))
+ (block
   ;;@ collisions/goog.java:74:6
   (local.set $$instance (struct.new $collisions.T (ref.as_non_null (global.get $collisions.T.vtable)) (ref.as_non_null (global.get $itable.empty)) (i32.const 0)))
   ;;@ collisions/goog.java:74:6
@@ -916,7 +926,7 @@
  (block
   ;;@ collisions/goog.java:80:4
   (local.set $t (block (result (ref null $java.lang.Number))
-   (local.set $$qualifier (call $$create__@collisions.T ))
+   (local.set $$qualifier (call $$create_$private__@collisions.T ))
    (call_ref $function.m_m__java_lang_Number_$pp_collisions (ref.as_non_null (local.get $$qualifier))(struct.get $collisions.T.vtable $m_m__java_lang_Number_$pp_collisions (struct.get $collisions.T $vtable(local.get $$qualifier))))
   ))
   ;;@ collisions/goog.java:81:4