Print better errors for unusual void, null and undefined types

src/diagnosticMessages.generated.ts

@@ -20,7 +20,7 @@ export enum DiagnosticCode {
   Conversion_from_type_0_to_1_will_require_an_explicit_cast_when_switching_between_32_64_bit = 201,
   Type_0_cannot_be_changed_to_type_1 = 202,
   Operation_0_cannot_be_applied_to_type_1 = 203,
-  Basic_type_0_cannot_be_nullable = 204,
+  Type_0_cannot_be_nullable = 204,
   Cannot_export_a_mutable_global = 205,
   Mutable_value_cannot_be_inlined = 206,
   Unmanaged_classes_cannot_extend_managed_classes_and_vice_versa = 207,
@@ -193,7 +193,7 @@ export function diagnosticCodeToString(code: DiagnosticCode): string {
     case 201: return "Conversion from type '{0}' to '{1}' will require an explicit cast when switching between 32/64-bit.";
     case 202: return "Type '{0}' cannot be changed to type '{1}'.";
     case 203: return "Operation '{0}' cannot be applied to type '{1}'.";
-    case 204: return "Basic type '{0}' cannot be nullable.";
+    case 204: return "Type '{0}' cannot be nullable.";
     case 205: return "Cannot export a mutable global.";
     case 206: return "Mutable value cannot be inlined.";
     case 207: return "Unmanaged classes cannot extend managed classes and vice-versa.";

src/diagnosticMessages.json

@@ -13,7 +13,7 @@
   "Conversion from type '{0}' to '{1}' will require an explicit cast when switching between 32/64-bit.": 201,
   "Type '{0}' cannot be changed to type '{1}'.": 202,
   "Operation '{0}' cannot be applied to type '{1}'.": 203,
-  "Basic type '{0}' cannot be nullable.": 204,
+  "Type '{0}' cannot be nullable.": 204,
   "Cannot export a mutable global.": 205,
   "Mutable value cannot be inlined.": 206,
   "Unmanaged classes cannot extend managed classes and vice-versa.": 207,

src/parser.ts

@@ -155,7 +155,11 @@ export class Parser extends DiagnosticEmitter {
     var statements = source.statements;
     while (!tn.skip(Token.ENDOFFILE)) {
       let statement = this.parseTopLevelStatement(tn, null);
-      if (statement) statements.push(statement);
+      if (statement) {
+        statements.push(statement);
+      } else {
+        this.skipStatement(tn);
+      }
     }
   }
 
@@ -538,6 +542,12 @@ export class Parser extends DiagnosticEmitter {
         Node.createSimpleTypeName("bool", tn.range()), [], false, tn.range(startPos, tn.pos)
       );
 
+    // 'null'
+    } else if (token == Token.NULL) {
+      type = Node.createNamedType(
+        Node.createSimpleTypeName("null", tn.range()), [], false, tn.range(startPos, tn.pos)
+      );
+
     // StringLiteral
     } else if (token == Token.STRINGLITERAL) {
       tn.readString();
@@ -550,7 +560,6 @@ export class Parser extends DiagnosticEmitter {
       let name = this.parseTypeName(tn);
       if (!name) return null;
       let parameters: TypeNode[] | null = null;
-      let nullable = false;
 
       // Name<T>
       if (tn.skip(Token.LESSTHAN)) {
@@ -570,31 +579,33 @@ export class Parser extends DiagnosticEmitter {
           return null;
         }
       }
-      // ... | null
-      while (tn.skip(Token.BAR)) {
-        if (tn.skip(Token.NULL)) {
-          nullable = true;
-        } else {
-          if (!suppressErrors) {
-            this.error(
-              DiagnosticCode._0_expected,
-              tn.range(tn.pos), "null"
-            );
-          }
-          return null;
-        }
-      }
       if (!parameters) parameters = [];
-      type = Node.createNamedType(name, parameters, nullable, tn.range(startPos, tn.pos));
+      type = Node.createNamedType(name, parameters, false, tn.range(startPos, tn.pos));
     } else {
       if (!suppressErrors) {
         this.error(
-          DiagnosticCode.Identifier_expected,
+          DiagnosticCode.Type_expected,
           tn.range()
         );
       }
       return null;
     }
+    // ... | null
+    while (tn.skip(Token.BAR)) {
+      if (tn.skip(Token.NULL)) {
+        type.isNullable = true;
+      } else {
+        let notNullStart = tn.pos;
+        let notNull = this.parseType(tn, false, true);
+        if (!suppressErrors) {
+          this.error(
+            DiagnosticCode._0_expected,
+            notNull ? notNull.range : tn.range(notNullStart), "null"
+          );
+        }
+        return null;
+      }
+    }
     // ... [][]
     while (tn.skip(Token.OPENBRACKET)) {
       let bracketStart = tn.tokenPos;

src/resolver.ts

@@ -205,7 +205,7 @@ export class Resolver extends DiagnosticEmitter {
           if (type.is(TypeFlags.REFERENCE)) return type.asNullable();
           if (reportMode == ReportMode.REPORT) {
             this.error(
-              DiagnosticCode.Basic_type_0_cannot_be_nullable,
+              DiagnosticCode.Type_0_cannot_be_nullable,
               node.range, type.toString()
             );
           }
@@ -238,7 +238,7 @@ export class Resolver extends DiagnosticEmitter {
         if (node.isNullable) {
           if (reportMode == ReportMode.REPORT) {
             this.error(
-              DiagnosticCode.Basic_type_0_cannot_be_nullable,
+              DiagnosticCode.Type_0_cannot_be_nullable,
               node.range, element.name + "/i32"
             );
           }
@@ -283,7 +283,7 @@ export class Resolver extends DiagnosticEmitter {
           if (!type.is(TypeFlags.REFERENCE)) {
             if (reportMode == ReportMode.REPORT) {
               this.error(
-                DiagnosticCode.Basic_type_0_cannot_be_nullable,
+                DiagnosticCode.Type_0_cannot_be_nullable,
                 nameNode.range, nameNode.identifier.text
               );
             }
@@ -333,7 +333,7 @@ export class Resolver extends DiagnosticEmitter {
         if (!type.is(TypeFlags.REFERENCE)) {
           if (reportMode == ReportMode.REPORT) {
             this.error(
-              DiagnosticCode.Basic_type_0_cannot_be_nullable,
+              DiagnosticCode.Type_0_cannot_be_nullable,
               nameNode.range, nameNode.identifier.text
             );
           }
@@ -2716,6 +2716,15 @@ export class Resolver extends DiagnosticEmitter {
         reportMode
       );
       if (!parameterType) return null;
+      if (parameterType == Type.void) {
+        if (reportMode == ReportMode.REPORT) {
+          this.error(
+            DiagnosticCode.Type_expected,
+            typeNode.range
+          );
+        }
+        return null;
+      }
       parameterTypes[i] = parameterType;
       parameterNames[i] = parameterDeclaration.name.text;
     }
@@ -3078,6 +3087,15 @@ export class Resolver extends DiagnosticEmitter {
                 instance.contextualTypeArguments,
                 reportMode
               );
+              if (fieldType == Type.void) {
+                if (reportMode == ReportMode.REPORT) {
+                  this.error(
+                    DiagnosticCode.Type_expected,
+                    fieldTypeNode.range
+                  );
+                }
+                break;
+              }
             }
             if (!fieldType) break; // did report above
             let fieldInstance = new Field(fieldPrototype, instance, fieldType);

std/assembly/builtins.ts

@@ -1,3 +1,5 @@
+type auto = i32;
+
 // @ts-ignore: decorator
 @builtin
 export declare function isInteger<T>(value?: T): bool;
@@ -40,11 +42,11 @@ export declare function isNullable<T>(value?: T): bool;
 
 // @ts-ignore: decorator
 @builtin
-export declare function isDefined(expression: void): bool;
+export declare function isDefined(expression: auto): bool;
 
 // @ts-ignore: decorator
 @builtin
-export declare function isConstant(expression: void): bool;
+export declare function isConstant(expression: auto): bool;
 
 // @ts-ignore: decorator
 @builtin
@@ -124,7 +126,7 @@ export declare function load<T>(ptr: usize, immOffset?: usize, immAlign?: usize)
 
 // @ts-ignore: decorator
 @unsafe @builtin
-export declare function store<T>(ptr: usize, value: void, immOffset?: usize, immAlign?: usize): void;
+export declare function store<T>(ptr: usize, value: auto, immOffset?: usize, immAlign?: usize): void;
 
 // @ts-ignore: decorator
 @builtin
@@ -156,7 +158,7 @@ export declare function unreachable(): void;
 
 // @ts-ignore: decorator
 @builtin
-export declare function changetype<T>(value: void): T;
+export declare function changetype<T>(value: auto): T;
 
 // @ts-ignore: decorator
 @builtin
@@ -168,7 +170,7 @@ export declare function unchecked<T>(expr: T): T;
 
 // @ts-ignore: decorator
 @builtin
-export declare function instantiate<T>(...args: void[]): T;
+export declare function instantiate<T>(...args: auto[]): T;
 
 export namespace atomic {
   // @ts-ignore: decorator
@@ -230,7 +232,7 @@ export const enum AtomicWaitResult {
 
 // @ts-ignore: decorator
 @builtin
-export declare function i8(value: void): i8;
+export declare function i8(value: auto): i8;
 
 export namespace i8 {
 
@@ -245,7 +247,7 @@ export namespace i8 {
 
 // @ts-ignore: decorator
 @builtin
-export declare function i16(value: void): i16;
+export declare function i16(value: auto): i16;
 
 export namespace i16 {
 
@@ -260,7 +262,7 @@ export namespace i16 {
 
 // @ts-ignore: decorator
 @builtin
-export declare function i32(value: void): i32;
+export declare function i32(value: auto): i32;
 
 export namespace i32 {
 
@@ -455,7 +457,7 @@ export namespace i32 {
 
 // @ts-ignore: decorator
 @builtin
-export declare function i64(value: void): i64;
+export declare function i64(value: auto): i64;
 
 export namespace i64 {
 
@@ -701,7 +703,7 @@ export namespace i64 {
 
 // @ts-ignore: decorator
 @builtin
-export declare function isize(value: void): isize;
+export declare function isize(value: auto): isize;
 
 export namespace isize {
 
@@ -720,7 +722,7 @@ export namespace isize {
 
 // @ts-ignore: decorator
 @builtin
-export declare function u8(value: void): u8;
+export declare function u8(value: auto): u8;
 
 export namespace u8 {
 
@@ -735,7 +737,7 @@ export namespace u8 {
 
 // @ts-ignore: decorator
 @builtin
-export declare function u16(value: void): u16;
+export declare function u16(value: auto): u16;
 
 export namespace u16 {
 
@@ -750,7 +752,7 @@ export namespace u16 {
 
 // @ts-ignore: decorator
 @builtin
-export declare function u32(value: void): u32;
+export declare function u32(value: auto): u32;
 
 export namespace u32 {
 
@@ -765,7 +767,7 @@ export namespace u32 {
 
 // @ts-ignore: decorator
 @builtin
-export declare function u64(value: void): u64;
+export declare function u64(value: auto): u64;
 
 export namespace u64 {
 
@@ -780,7 +782,7 @@ export namespace u64 {
 
 // @ts-ignore: decorator
 @builtin
-export declare function usize(value: void): usize;
+export declare function usize(value: auto): usize;
 
 export namespace usize {
 
@@ -797,7 +799,7 @@ export namespace usize {
 
 // @ts-ignore: decorator
 @builtin
-export declare function bool(value: void): bool;
+export declare function bool(value: auto): bool;
 
 export namespace bool {
 
@@ -812,7 +814,7 @@ export namespace bool {
 
 // @ts-ignore: decorator
 @builtin
-export declare function f32(value: void): f32;
+export declare function f32(value: auto): f32;
 
 export namespace f32 {
 
@@ -891,7 +893,7 @@ export namespace f32 {
 
 // @ts-ignore: decorator
 @builtin
-export declare function f64(value: void): f64;
+export declare function f64(value: auto): f64;
 
 export namespace f64 {
 

tests/compiler/basic-nullable.json

@@ -3,7 +3,7 @@
     "--runtime none"
   ],
   "stderr": [
-    "AS204: Basic type 'i32' cannot be nullable.",
+    "AS204: Type 'i32' cannot be nullable.",
     "EOF"
   ]
 }

tests/parser/continue-on-error.ts.fixture.ts

@@ -1,7 +1,3 @@
-;
-a;
-from;
-"./other";
 do {
   ;
 } while (false);

tests/parser/regexp.ts.fixture.ts

@@ -2,7 +2,6 @@
 /(abc)\//;
 var re = /(abc)\//ig;
 var noRe = !/(abc)\//i;
-b / ig;
 /(abc)\//iig;
 /(abc)\//iX;
 false && /abc/gX.test(someString) || true;