fix(pacmak): illegal static overrides in java & c#

Stop emitting "overrides" in the respecting language idiomatic way for
static methods and properties (while ES6 supports those, this is not
true of Java and C#).

In Java, this is mostly getting rid of `@Overrides` on static
declarations. C# *allows* (but does not require) explicitly hiding the
parent declaration using the `new` keyword. This was introduced as it
provides additional safeguards against our generating incorrect code.

Fixes #2358

packages/jsii-calc/lib/compliance.ts

@@ -2840,3 +2840,31 @@ export namespace LevelOne {
     readonly value: boolean;
   }
 }
+
+/**
+ * Static methods that override parent class are technically overrides (the
+ * inheritance of statics is part of the ES6 specification), but certain other
+ * languages such as Java do not share this feature.
+ */
+export class StaticHelloParent {
+  public static get property(): number {
+    return 1337;
+  }
+
+  public static method(): void {
+    /* A static method */
+  }
+}
+export class StaticHelloChild extends StaticHelloParent {
+  public static get property(): number {
+    return 42;
+  }
+
+  public static method(): void {
+    /* An ES6 Override */
+  }
+
+  private constructor() {
+    super();
+  }
+}

packages/jsii-calc/test/assembly.jsii

@@ -11422,6 +11422,101 @@
         }
       ]
     },
+    "jsii-calc.StaticHelloChild": {
+      "assembly": "jsii-calc",
+      "base": "jsii-calc.StaticHelloParent",
+      "docs": {
+        "stability": "stable"
+      },
+      "fqn": "jsii-calc.StaticHelloChild",
+      "kind": "class",
+      "locationInModule": {
+        "filename": "lib/compliance.ts",
+        "line": 2858
+      },
+      "methods": [
+        {
+          "docs": {
+            "stability": "stable"
+          },
+          "locationInModule": {
+            "filename": "lib/compliance.ts",
+            "line": 2863
+          },
+          "name": "method",
+          "overrides": "jsii-calc.StaticHelloParent",
+          "static": true
+        }
+      ],
+      "name": "StaticHelloChild",
+      "properties": [
+        {
+          "docs": {
+            "stability": "stable"
+          },
+          "immutable": true,
+          "locationInModule": {
+            "filename": "lib/compliance.ts",
+            "line": 2859
+          },
+          "name": "property",
+          "overrides": "jsii-calc.StaticHelloParent",
+          "static": true,
+          "type": {
+            "primitive": "number"
+          }
+        }
+      ]
+    },
+    "jsii-calc.StaticHelloParent": {
+      "assembly": "jsii-calc",
+      "docs": {
+        "stability": "stable",
+        "summary": "Static methods that override parent class are technically overrides (the inheritance of statics is part of the ES6 specification), but certain other languages such as Java do not share this feature."
+      },
+      "fqn": "jsii-calc.StaticHelloParent",
+      "initializer": {
+        "docs": {
+          "stability": "stable"
+        }
+      },
+      "kind": "class",
+      "locationInModule": {
+        "filename": "lib/compliance.ts",
+        "line": 2849
+      },
+      "methods": [
+        {
+          "docs": {
+            "stability": "stable"
+          },
+          "locationInModule": {
+            "filename": "lib/compliance.ts",
+            "line": 2854
+          },
+          "name": "method",
+          "static": true
+        }
+      ],
+      "name": "StaticHelloParent",
+      "properties": [
+        {
+          "docs": {
+            "stability": "stable"
+          },
+          "immutable": true,
+          "locationInModule": {
+            "filename": "lib/compliance.ts",
+            "line": 2850
+          },
+          "name": "property",
+          "static": true,
+          "type": {
+            "primitive": "number"
+          }
+        }
+      ]
+    },
     "jsii-calc.Statics": {
       "assembly": "jsii-calc",
       "docs": {
@@ -14345,5 +14440,5 @@
     }
   },
   "version": "0.0.0",
-  "fingerprint": "XfCnzPEGbEJR6hhBX8zWyFzWJP2wH9ztW2ZcW6Wdb+4="
+  "fingerprint": "lMjqpro90RI1jZrcELFmEzcSJQCxkEhm77olVYW0fc8="
 }

packages/jsii-pacmak/lib/targets/dotnet/dotnetgenerator.ts

@@ -476,7 +476,7 @@ export class DotNetGenerator extends Generator {
     const returnType = method.returns
       ? this.typeresolver.toDotNetType(method.returns.type)
       : 'void';
-    let staticKeyWord = '';
+    const staticKeyWord = method.static ? 'static ' : '';
     let overrideKeyWord = '';
     let virtualKeyWord = '';
 
@@ -496,12 +496,11 @@ export class DotNetGenerator extends Generator {
         overrides = true;
       }
     }
-    if (method.static) {
-      staticKeyWord = 'static ';
-    } else if (overrides) {
+    if (overrides) {
       // Add the override key word if the method is emitted for a proxy or data type or is defined on an ancestor
-      overrideKeyWord = 'override ';
+      overrideKeyWord = method.static ? 'new ' : 'override ';
     } else if (
+      !method.static &&
       (method.abstract || !definedOnAncestor) &&
       !emitForProxyOrDatatype
     ) {
@@ -833,7 +832,7 @@ export class DotNetGenerator extends Generator {
       );
       if (implementedInBase || datatype || proxy) {
         // Override if the property is in a datatype or proxy class or declared in a parent class
-        isOverrideKeyWord = 'override ';
+        isOverrideKeyWord = prop.static ? 'new ' : 'override ';
       } else if (prop.abstract) {
         // Abstract members get decorated as such
         isAbstractKeyword = 'abstract ';
@@ -845,7 +844,7 @@ export class DotNetGenerator extends Generator {
 
     const propTypeFQN = this.typeresolver.toDotNetType(prop.type);
     const isOptional = prop.optional ? '?' : '';
-    const statement = `${access} ${isAbstractKeyword}${isVirtualKeyWord}${isOverrideKeyWord}${staticKeyWord}${propTypeFQN}${isOptional} ${propName}`;
+    const statement = `${access} ${isAbstractKeyword}${isVirtualKeyWord}${staticKeyWord}${isOverrideKeyWord}${propTypeFQN}${isOptional} ${propName}`;
     this.code.openBlock(statement);
 
     // Emit getters

packages/jsii-pacmak/lib/targets/java.ts

@@ -1274,7 +1274,7 @@ class JavaGenerator extends Generator {
     if (includeGetter) {
       this.code.line();
       this.addJavaDocs(prop);
-      if (overrides) {
+      if (overrides && !prop.static) {
         this.code.line('@Override');
       }
       this.emitStabilityAnnotations(prop);
@@ -1307,7 +1307,7 @@ class JavaGenerator extends Generator {
       for (const type of setterTypes) {
         this.code.line();
         this.addJavaDocs(prop);
-        if (overrides) {
+        if (overrides && !prop.static) {
           this.code.line('@Override');
         }
         this.emitStabilityAnnotations(prop);
@@ -1364,7 +1364,7 @@ class JavaGenerator extends Generator {
     this.code.line();
     this.addJavaDocs(method);
     this.emitStabilityAnnotations(method);
-    if (overrides) {
+    if (overrides && !method.static) {
       this.code.line('@Override');
     }
     if (method.abstract && !defaultImpl) {