native method handling for type-checker

Author: mattcce

src/types/ast/extractor.ts

@@ -1294,8 +1294,14 @@ class AstExtractor extends BaseJavaCstVisitor {
     return getIdentifier(ctx.Identifier![0])
   }
 
-  methodBody(ctx: JavaParser.MethodBodyCtx): AST.MethodBody {
+  methodBody(ctx: JavaParser.MethodBodyCtx): AST.MethodBody | undefined {
     if (ctx.block) return this.visit(ctx.block)
+
+    // handle only semicolon i.e. empty block
+    if (ctx.Semicolon) {
+      return undefined
+    }
+
     throw new Error('Not implemented')
   }
 

src/types/ast/specificationTypes.ts

@@ -742,7 +742,7 @@ export type MethodDeclaration = {
   kind: 'MethodDeclaration'
   methodModifiers: MethodModifier[]
   methodHeader: MethodHeader
-  methodBody: MethodBody
+  methodBody: MethodBody | undefined
   location: Location
 }
 

src/types/checker/index.ts

@@ -7,6 +7,7 @@ import {
   BadOperandTypesError,
   CannotFindSymbolError,
   IncompatibleTypesError,
+  MissingMethodBodyError,
   NotApplicableToExpressionTypeError,
   TypeCheckerError,
   TypeCheckerInternalError,
@@ -518,6 +519,19 @@ export const typeCheckBody = (node: Node, frame: Frame = Frame.globalFrame()): R
               errors.push(...methodErrors)
               break
             }
+
+            // skip type checking for bodies of native methods (admit empty body)
+            if (bodyDeclaration.methodModifiers.map(i => i.identifier).includes('native')) {
+              console.log(bodyDeclaration)
+              break
+            }
+
+            // empty body is error
+            if (bodyDeclaration.methodBody === undefined) {
+              errors.push(new MissingMethodBodyError(bodyDeclaration.location))
+              break
+            }
+
             const { errors: checkErrors } = typeCheckBody(bodyDeclaration.methodBody, methodFrame)
             if (checkErrors.length > 0) errors.push(...checkErrors)
             break

src/types/errors.ts

@@ -118,6 +118,12 @@ export class MethodCannotBeAppliedError extends TypeCheckerError {
   }
 }
 
+export class MissingMethodBodyError extends TypeCheckerError {
+  constructor(location?: Location) {
+    super('missing method body', location)
+  }
+}
+
 export class ModifierNotAllowedHereError extends TypeCheckerError {
   constructor(location?: Location) {
     super('modifier not allowed here', location)