Add various useful builtins (#739)

isVoid, lengthof, nameof, returnof and function type support for idof

src/builtins.ts

@@ -102,6 +102,7 @@ export namespace BuiltinSymbols {
   export const isDefined = "~lib/builtins/isDefined";
   export const isConstant = "~lib/builtins/isConstant";
   export const isManaged = "~lib/builtins/isManaged";
+  export const isVoid = "~lib/builtins/isVoid";
 
   export const clz = "~lib/builtins/clz";
   export const ctz = "~lib/builtins/ctz";
@@ -135,6 +136,8 @@ export namespace BuiltinSymbols {
   export const sizeof = "~lib/builtins/sizeof";
   export const alignof = "~lib/builtins/alignof";
   export const offsetof = "~lib/builtins/offsetof";
+  export const nameof = "~lib/builtins/nameof";
+  export const lengthof = "~lib/builtins/lengthof";
   export const select = "~lib/builtins/select";
   export const unreachable = "~lib/builtins/unreachable";
   export const changetype = "~lib/builtins/changetype";
@@ -658,6 +661,30 @@ export function compileCall(
       if (!type) return module.unreachable();
       return module.i32(type.isManaged ? 1 : 0);
     }
+    case BuiltinSymbols.isVoid: { // isVoid<T>() -> bool
+      let type = evaluateConstantType(compiler, typeArguments, operands, reportNode);
+      compiler.currentType = Type.bool;
+      if (!type) return module.unreachable();
+      return module.i32(type.kind == TypeKind.VOID ? 1 : 0);
+    }
+    case BuiltinSymbols.lengthof: { // lengthof<T>(): i32
+      let type = evaluateConstantType(compiler, typeArguments, operands, reportNode);
+      compiler.currentType = Type.i32;
+      if (!type) return module.unreachable();
+
+      // Report if there is no call signature
+      let signatureReference = type.signatureReference;
+      if (!signatureReference) {
+        compiler.error(
+          DiagnosticCode.Type_0_has_no_call_signatures,
+          reportNode.range, "1", (typeArguments ? typeArguments.length : 1).toString(10)
+        );
+        return module.unreachable();
+      }
+
+      let parameterNames = signatureReference.parameterNames;
+      return module.i32(!parameterNames ? 0 : parameterNames.length);
+    }
     case BuiltinSymbols.sizeof: { // sizeof<T!>() -> usize
       compiler.currentType = compiler.options.usizeType;
       if (
@@ -771,6 +798,45 @@ export function compileCall(
         }
       }
     }
+    case BuiltinSymbols.nameof: {
+      // Check to make sure a parameter or a type was passed to the builtin
+      let resultType = evaluateConstantType(compiler, typeArguments, operands, reportNode);
+      if (!resultType) return module.unreachable();
+
+      let value: string;
+      if (resultType.is(TypeFlags.REFERENCE)) {
+        let classReference = resultType.classReference;
+        if (!classReference) {
+          assert(resultType.signatureReference);
+          value = "Function";
+        } else {
+          value = classReference.name;
+        }
+      } else {
+        switch (resultType.kind) {
+          case TypeKind.BOOL: { value = "bool"; break; }
+          case TypeKind.I8: { value = "i8"; break; }
+          case TypeKind.U8: { value = "u8"; break; }
+          case TypeKind.I16: { value = "i16"; break; }
+          case TypeKind.U16: { value = "u16"; break; }
+          case TypeKind.I32: { value = "i32"; break; }
+          case TypeKind.U32: { value = "u32"; break; }
+          case TypeKind.F32: { value = "f32"; break; }
+          case TypeKind.I64: { value = "i64"; break; }
+          case TypeKind.U64: { value = "u64"; break; }
+          case TypeKind.F64: { value = "f64"; break; }
+          case TypeKind.ISIZE: { value = "isize"; break; }
+          case TypeKind.USIZE: { value = "usize"; break; }
+          case TypeKind.V128: { value = "v128"; break; }
+          // If the kind is not set properly, throw an error.
+          // The default case falls through to satisfy that value is always set, and never null.
+          default: assert(false);
+          case TypeKind.VOID: { value = "void"; break; }
+        }
+      }
+
+      return compiler.ensureStaticString(value);
+    }
 
     // === Math ===================================================================================
 
@@ -3593,6 +3659,11 @@ export function compileCall(
       let type = evaluateConstantType(compiler, typeArguments, operands, reportNode);
       compiler.currentType = Type.u32;
       if (!type) return module.unreachable();
+      let signatureReference = type.signatureReference;
+      if (type.is(TypeFlags.REFERENCE) && signatureReference !== null) {
+        return module.i32(signatureReference.id);
+      }
+
       let classReference = type.classReference;
       if (!classReference || classReference.hasDecorator(DecoratorFlags.UNMANAGED)) {
         compiler.error(

src/common.ts

@@ -136,6 +136,7 @@ export namespace CommonSymbols {
   export const native = "native";
   export const indexof = "indexof";
   export const valueof = "valueof";
+  export const returnof = "returnof";
   // aliases
   export const null_ = "null";
   export const true_ = "true";

src/compiler.ts

@@ -344,7 +344,7 @@ export class Compiler extends DiagnosticEmitter {
     program.initialize(options);
 
     // set up the main start function
-    var startFunctionInstance = program.makeNativeFunction("start", new Signature([], Type.void));
+    var startFunctionInstance = program.makeNativeFunction("start", new Signature(program, [], Type.void));
     startFunctionInstance.internalName = "start";
     var startFunctionBody = new Array<ExpressionRef>();
     this.currentFlow = startFunctionInstance.flow;
@@ -6367,7 +6367,7 @@ export class Compiler extends DiagnosticEmitter {
     assert(operandIndex == minOperands);
 
     // create the trampoline element
-    var trampolineSignature = new Signature(originalParameterTypes, returnType, thisType);
+    var trampolineSignature = new Signature(this.program, originalParameterTypes, returnType, thisType);
     trampolineSignature.requiredParameters = maxArguments;
     trampolineSignature.parameterNames = originalSignature.parameterNames;
     trampoline = new Function(
@@ -7082,7 +7082,7 @@ export class Compiler extends DiagnosticEmitter {
         }
       }
 
-      let signature = new Signature(parameterTypes, returnType, thisType);
+      let signature = new Signature(this.program, parameterTypes, returnType, thisType);
       signature.requiredParameters = numParameters; // !
       signature.parameterNames = parameterNames;
       instance = new Function(
@@ -7845,7 +7845,7 @@ export class Compiler extends DiagnosticEmitter {
             CommonFlags.INSTANCE | CommonFlags.CONSTRUCTOR
           )
         ),
-        new Signature(null, classInstance.type, classInstance.type),
+        new Signature(this.program, null, classInstance.type, classInstance.type),
         null
       );
     }
@@ -9005,6 +9005,7 @@ export class Compiler extends DiagnosticEmitter {
     flow.popBreakLabel();
     return module.block(label, conditions, NativeType.I32);
   }
+
 }
 
 // helpers

src/diagnosticMessages.generated.ts

@@ -136,6 +136,7 @@ export enum DiagnosticCode {
   Namespace_0_has_no_exported_member_1 = 2694,
   Required_type_parameters_may_not_follow_optional_type_parameters = 2706,
   Duplicate_property_0 = 2718,
+  Type_0_has_no_call_signatures = 2757,
   File_0_not_found = 6054,
   Numeric_separators_are_not_allowed_here = 6188,
   Multiple_consecutive_numeric_separators_are_not_permitted = 6189,
@@ -275,6 +276,7 @@ export function diagnosticCodeToString(code: DiagnosticCode): string {
     case 2694: return "Namespace '{0}' has no exported member '{1}'.";
     case 2706: return "Required type parameters may not follow optional type parameters.";
     case 2718: return "Duplicate property '{0}'.";
+    case 2757: return "Type '{0}' has no call signatures.";
     case 6054: return "File '{0}' not found.";
     case 6188: return "Numeric separators are not allowed here.";
     case 6189: return "Multiple consecutive numeric separators are not permitted.";

src/diagnosticMessages.json

@@ -130,6 +130,7 @@
   "Namespace '{0}' has no exported member '{1}'.": 2694,
   "Required type parameters may not follow optional type parameters.": 2706,
   "Duplicate property '{0}'.": 2718,
+  "Type '{0}' has no call signatures.": 2757,
 
   "File '{0}' not found.": 6054,
   "Numeric separators are not allowed here.": 6188,

src/program.ts

@@ -336,6 +336,8 @@ export class Program extends DiagnosticEmitter {
   typeClasses: Map<TypeKind,Class> = new Map();
   /** Managed classes contained in the program, by id. */
   managedClasses: Map<i32,Class> = new Map();
+  /** A set of unique function signatures contained in the program, by id. */
+  uniqueSignatures: Signature[] = new Array<Signature>(0);
 
   // standard references
 
@@ -403,7 +405,8 @@ export class Program extends DiagnosticEmitter {
 
   /** Next class id. */
   nextClassId: u32 = 0;
-
+  /** Next signature id. */
+  nextSignatureId: i32 = 0;
   /** Constructs a new program, optionally inheriting parser diagnostics. */
   constructor(
     /** Shared array of diagnostic messages (emitted so far). */
@@ -579,6 +582,12 @@ export class Program extends DiagnosticEmitter {
       this.makeNativeTypeDeclaration(CommonSymbols.valueof, CommonFlags.EXPORT | CommonFlags.GENERIC),
       DecoratorFlags.BUILTIN
     ));
+    this.nativeFile.add(CommonSymbols.returnof, new TypeDefinition(
+      CommonSymbols.returnof,
+      this.nativeFile,
+      this.makeNativeTypeDeclaration(CommonSymbols.returnof, CommonFlags.EXPORT | CommonFlags.GENERIC),
+      DecoratorFlags.BUILTIN
+    ));
     if (options.hasFeature(Feature.SIMD)) this.registerNativeType(CommonSymbols.v128, Type.v128);
 
     // register compiler hints
@@ -2141,7 +2150,7 @@ export class File extends Element {
     program.filesByName.set(this.internalName, this);
     var startFunction = this.program.makeNativeFunction(
       "start:" + this.internalName,
-      new Signature(null, Type.void),
+      new Signature(program, null, Type.void),
       this
     );
     startFunction.internalName = startFunction.name;

src/resolver.ts

@@ -273,6 +273,7 @@ export class Resolver extends DiagnosticEmitter {
           case CommonSymbols.native: return this.resolveBuiltinNativeType(node, ctxElement, ctxTypes, reportMode);
           case CommonSymbols.indexof: return this.resolveBuiltinIndexofType(node, ctxElement, ctxTypes, reportMode);
           case CommonSymbols.valueof: return this.resolveBuiltinValueofType(node, ctxElement, ctxTypes, reportMode);
+          case CommonSymbols.returnof: return this.resolveBuiltinReturnTypeType(node, ctxElement, ctxTypes, reportMode);
         }
       }
 
@@ -405,7 +406,7 @@ export class Resolver extends DiagnosticEmitter {
       );
       if (!returnType) return null;
     }
-    var signature = new Signature(parameterTypes, returnType, thisType);
+    var signature = new Signature(this.program, parameterTypes, returnType, thisType);
     signature.parameterNames = parameterNames;
     signature.requiredParameters = requiredParameters;
     signature.hasRest = hasRest;
@@ -550,6 +551,41 @@ export class Resolver extends DiagnosticEmitter {
     return null;
   }
 
+  private resolveBuiltinReturnTypeType(
+    /** The type to resolve. */
+    node: NamedTypeNode,
+    /** Contextual element. */
+    ctxElement: Element,
+    /** Contextual types, i.e. `T`. */
+    ctxTypes: Map<string,Type> | null = null,
+    /** How to proceed with eventualy diagnostics. */
+    reportMode: ReportMode = ReportMode.REPORT
+  ): Type | null {
+    var typeArgumentNodes = node.typeArguments;
+    if (!(typeArgumentNodes && typeArgumentNodes.length == 1)) {
+      if (reportMode == ReportMode.REPORT) {
+        this.error(
+          DiagnosticCode.Expected_0_type_arguments_but_got_1,
+          node.range, "1", (typeArgumentNodes ? typeArgumentNodes.length : 1).toString(10)
+        );
+      }
+      return null;
+    }
+    var typeArgument = this.resolveType(typeArgumentNodes[0], ctxElement, ctxTypes, reportMode);
+    if (!typeArgument) return null;
+    var signatureReference = typeArgument.signatureReference;
+    if (!signatureReference) {
+      if (reportMode == ReportMode.REPORT) {
+        this.error(
+          DiagnosticCode.Type_0_has_no_call_signatures,
+          typeArgumentNodes[0].range, typeArgument.toString()
+        );
+      }
+      return null;
+    }
+    return signatureReference.returnType;
+  }
+
   /** Resolves a type name to the program element it refers to. */
   resolveTypeName(
     /** The type name to resolve. */
@@ -1551,7 +1587,7 @@ export class Resolver extends DiagnosticEmitter {
       returnType = type;
     }
 
-    var signature = new Signature(parameterTypes, returnType, thisType);
+    var signature = new Signature(this.program, parameterTypes, returnType, thisType);
     signature.parameterNames = parameterNames;
     signature.requiredParameters = requiredParameters;
 

src/types.ts

@@ -556,7 +556,8 @@ export function typesToString(types: Type[]): string {
 
 /** Represents a fully resolved function signature. */
 export class Signature {
-
+  /** The unique program id that represents this signature. */
+  id: u32 = 0;
   /** Parameter types, if any, excluding `this`. */
   parameterTypes: Type[];
   /** Parameter names, if known, excluding `this`. */
@@ -573,9 +574,12 @@ export class Signature {
   cachedFunctionTarget: FunctionTarget | null = null;
   /** Respective function type. */
   type: Type;
+  /** The program that created this signature. */
+  program: Program;
 
   /** Constructs a new signature. */
   constructor(
+    program: Program,
     parameterTypes: Type[] | null = null,
     returnType: Type | null = null,
     thisType: Type | null = null
@@ -585,8 +589,21 @@ export class Signature {
     this.requiredParameters = 0;
     this.returnType = returnType ? returnType : Type.void;
     this.thisType = thisType;
+    this.program = program;
     this.hasRest = false;
     this.type = Type.u32.asFunction(this);
+
+    var signatureTypes = program.uniqueSignatures;
+    var length = signatureTypes.length;
+    for (let i = 0; i < length; i++) {
+      let compare = signatureTypes[i];
+      if (this.equals(compare)) {
+        this.id = compare.id;
+        return this;
+      }
+    }
+    program.uniqueSignatures.push(this);
+    this.id = program.nextSignatureId++;
   }
 
   asFunctionTarget(program: Program): FunctionTarget {
@@ -606,23 +623,28 @@ export class Signature {
 
   /** Tests if a value of this function type is assignable to a target of the specified function type. */
   isAssignableTo(target: Signature): bool {
+    return this.equals(target);
+  }
+
+  /** Tests to see if a signature equals another signature. */
+  equals(value: Signature): bool {
     // TODO: maybe cache results?
 
     // check `this` type
     var thisThisType = this.thisType;
-    var targetThisType = target.thisType;
+    var targetThisType = value.thisType;
     if (thisThisType) {
       if (!(targetThisType && thisThisType.isAssignableTo(targetThisType))) return false;
     } else if (targetThisType) {
       return false;
     }
 
     // check rest parameter
-    if (this.hasRest != target.hasRest) return false; // TODO
+    if (this.hasRest != value.hasRest) return false; // TODO
 
     // check parameter types
     var thisParameterTypes = this.parameterTypes;
-    var targetParameterTypes = target.parameterTypes;
+    var targetParameterTypes = value.parameterTypes;
     var numParameters = thisParameterTypes.length;
     if (numParameters != targetParameterTypes.length) return false;
     for (let i = 0; i < numParameters; ++i) {
@@ -633,7 +655,7 @@ export class Signature {
 
     // check return type
     var thisReturnType = this.returnType;
-    var targetReturnType = target.returnType;
+    var targetReturnType = value.returnType;
     return thisReturnType == targetReturnType || thisReturnType.isAssignableTo(targetReturnType);
   }