fix: Simplify compileCallExpression (#2558)

Author: dcodeIO

src/compiler.ts

@@ -5990,11 +5990,8 @@ export class Compiler extends DiagnosticEmitter {
     if (!target) return module.unreachable();
     let thisExpression = this.resolver.currentThisExpression;
 
-    let signature: Signature | null;
-    let functionArg: ExpressionRef;
+    // handle direct call
     switch (target.kind) {
-
-      // direct call: concrete function
       case ElementKind.FunctionPrototype: {
         let functionPrototype = <FunctionPrototype>target;
         if (functionPrototype.hasDecorator(DecoratorFlags.Builtin)) {
@@ -6024,128 +6021,35 @@ export class Compiler extends DiagnosticEmitter {
           constraints
         );
       }
+    }
 
-      // indirect call: first-class function (non-generic, can't be inlined)
-      case ElementKind.Local: {
-        let local = <Local>target;
-        signature = local.type.signatureReference;
-        if (signature) {
-          if (local.parent != flow.targetFunction) {
-            // TODO: closures
-            this.error(
-              DiagnosticCode.Not_implemented_0,
-              expression.range,
-              "Closures"
-            );
-            return module.unreachable();
-          }
-          if (local.is(CommonFlags.Inlined)) {
-            let inlinedValue = local.constantIntegerValue;
-            if (this.options.isWasm64) {
-              functionArg = module.i64(i64_low(inlinedValue), i64_high(inlinedValue));
-            } else {
-              assert(!i64_high(inlinedValue));
-              functionArg = module.i32(i64_low(inlinedValue));
-            }
-          } else {
-            functionArg = module.local_get(local.index, this.options.sizeTypeRef);
-          }
-          break;
-        }
-        this.error(
-          DiagnosticCode.Cannot_invoke_an_expression_whose_type_lacks_a_call_signature_Type_0_has_no_compatible_call_signatures,
-          expression.range, local.type.toString()
-        );
-        return module.unreachable();
-      }
-      case ElementKind.Global: {
-        let global = <Global>target;
-        signature = global.type.signatureReference;
-        if (signature) {
-          functionArg = module.global_get(global.internalName, global.type.toRef());
-          break;
-        }
-        this.error(
-          DiagnosticCode.Cannot_invoke_an_expression_whose_type_lacks_a_call_signature_Type_0_has_no_compatible_call_signatures,
-          expression.range, global.type.toString()
+    // handle indirect call
+    let functionArg = this.compileExpression(expression.expression, Type.auto);
+    let signature = this.currentType.getSignature();
+    if (signature) {
+      return this.compileCallIndirect(
+        signature,
+        functionArg,
+        expression.args,
+        expression,
+        0,
+        contextualType == Type.void
+      );
+    }
+    this.error(
+      DiagnosticCode.Cannot_invoke_an_expression_whose_type_lacks_a_call_signature_Type_0_has_no_compatible_call_signatures,
+      expression.range, this.currentType.toString()
+    );
+    if (target.kind == ElementKind.PropertyPrototype) {
+      let getterPrototype = (<PropertyPrototype>target).getterPrototype;
+      if (getterPrototype) {
+        this.infoRelated(
+          DiagnosticCode.This_expression_is_not_callable_because_it_is_a_get_accessor_Did_you_mean_to_use_it_without,
+          expression.range, getterPrototype.identifierNode.range
         );
-        return module.unreachable();
-      }
-      case ElementKind.PropertyPrototype: {
-        let propertyInstance = this.resolver.resolveProperty(<PropertyPrototype>target);
-        if (!propertyInstance) return module.unreachable();
-        target = propertyInstance;
-        // fall-through
-      }
-      case ElementKind.Property: {
-        let propertyInstance = <Property>target;
-        let getterInstance = propertyInstance.getterInstance;
-        let type = assert(this.resolver.getTypeOfElement(target));
-
-        if (!getterInstance) {
-          this.error(
-            DiagnosticCode.Cannot_invoke_an_expression_whose_type_lacks_a_call_signature_Type_0_has_no_compatible_call_signatures,
-            expression.range, type.toString()
-          );
-          return module.unreachable();
-        }
-
-        let thisArg: ExpressionRef = 0;
-        if (propertyInstance.is(CommonFlags.Instance)) {
-          thisArg = this.compileExpression(
-            assert(thisExpression),
-            assert(getterInstance.signature.thisType),
-            Constraints.ConvImplicit | Constraints.IsThis
-          );
-        }
-        functionArg = this.compileCallDirect(getterInstance, [], expression.expression, thisArg);
-        signature = this.currentType.signatureReference;
-        if (!signature) {
-          this.error(
-            DiagnosticCode.Cannot_invoke_an_expression_whose_type_lacks_a_call_signature_Type_0_has_no_compatible_call_signatures,
-            expression.range, this.currentType.toString()
-          );
-          return module.unreachable();
-        }
-        break;
-      }
-      case ElementKind.Class: {
-        let classInstance = <Class>target;
-        let typeArguments = classInstance.getTypeArgumentsTo(this.program.functionPrototype);
-        if (typeArguments && typeArguments.length > 0) {
-          let ftype = typeArguments[0];
-          signature = ftype.getSignature();
-          functionArg = this.compileExpression(expression.expression, ftype, Constraints.ConvImplicit);
-          break;
-        }
-        // fall-through
-      }
-
-      // not supported
-      default: {
-        let type = this.resolver.getTypeOfElement(target);
-        if (type) {
-          this.error(
-            DiagnosticCode.Type_0_has_no_call_signatures,
-            expression.range, type.toString()
-          );
-        } else {
-          this.error(
-            DiagnosticCode.Expression_cannot_be_represented_by_a_type,
-            expression.range
-          );
-        }
-        return module.unreachable();
       }
     }
-    return this.compileCallIndirect(
-      assert(signature), // FIXME: bootstrap can't see this yet
-      functionArg,
-      expression.args,
-      expression,
-      0,
-      contextualType == Type.void
-    );
+    return module.unreachable();
   }
 
   /** Compiles the given arguments like a call expression according to the specified context. */

src/diagnosticMessages.json

@@ -199,6 +199,7 @@
   "File '{0}' not found.": 6054,
   "Numeric separators are not allowed here.": 6188,
   "Multiple consecutive numeric separators are not permitted.": 6189,
+  "This expression is not callable because it is a 'get' accessor. Did you mean to use it without '()'?": 6234,
   "'super' must be called before accessing 'this' in the constructor of a derived class.": 17009,
   "'super' must be called before accessing a property of 'super' in the constructor of a derived class.": 17011
 }

src/resolver.ts

@@ -2441,35 +2441,32 @@ export class Resolver extends DiagnosticEmitter {
         ) {
           return this.resolveExpression(node.args[0], ctxFlow, ctxType, reportMode);
         }
-        let instance = this.maybeInferCall(node, functionPrototype, ctxFlow, reportMode);
-        if (!instance) return null;
-        return instance.signature.returnType;
+        let functionInstance = this.maybeInferCall(node, functionPrototype, ctxFlow, reportMode);
+        if (!functionInstance) return null;
+        target = functionInstance;
+        // fall-through
+      }
+      case ElementKind.Function: {
+        return (<Function>target).signature.returnType;
       }
       case ElementKind.PropertyPrototype: {
         let propertyInstance = this.resolveProperty(<PropertyPrototype>target, reportMode);
         if (!propertyInstance) return null;
         target = propertyInstance;
         // fall-through
       }
-      case ElementKind.Global:
-      case ElementKind.Local:
-      case ElementKind.Property: {
-        let varType = (<VariableLikeElement>target).type;
-        let varElement = this.getElementOfType(varType);
-        if (!varElement || varElement.kind != ElementKind.Class) {
-          break;
-        }
-        target = varElement;
+      default: {
+        if (!isTypedElement(target.kind)) break;
+        let targetElement = this.getElementOfType((<TypedElement>target).type);
+        if (!targetElement || targetElement.kind != ElementKind.Class) break;
+        target = targetElement;
         // fall-through
       }
       case ElementKind.Class: {
         let typeArguments = (<Class>target).getTypeArgumentsTo(this.program.functionPrototype);
-        if (typeArguments && typeArguments.length > 0) {
-          let ftype = typeArguments[0];
-          let signatureReference = assert(ftype.signatureReference);
-          return signatureReference.returnType;
-        }
-        break;
+        if (!(typeArguments && typeArguments.length)) break;
+        let signature = assert(typeArguments[0].getSignature());
+        return signature.returnType;
       }
     }
     if (reportMode == ReportMode.Report) {

tests/compiler/assert-nonnull.debug.wat

@@ -69,24 +69,28 @@
   i32.load $0 offset=4
  )
  (func $assert-nonnull/testFn (type $i32_=>_i32) (param $fn i32) (result i32)
+  (local $1 i32)
   i32.const 0
   global.set $~argumentsLength
   local.get $fn
+  local.tee $1
+  if (result i32)
+   local.get $1
+  else
+   i32.const 32
+   i32.const 96
+   i32.const 35
+   i32.const 10
+   call $~lib/builtins/abort
+   unreachable
+  end
   i32.load $0
   call_indirect $0 (type $none_=>_i32)
  )
  (func $assert-nonnull/Foo#get:baz (type $i32_=>_i32) (param $this i32) (result i32)
   local.get $this
   i32.load $0 offset=4
  )
- (func $assert-nonnull/testObjFn (type $i32_=>_i32) (param $foo i32) (result i32)
-  i32.const 0
-  global.set $~argumentsLength
-  local.get $foo
-  call $assert-nonnull/Foo#get:baz
-  i32.load $0
-  call_indirect $0 (type $none_=>_i32)
- )
  (func $~stack_check (type $none_=>_none)
   global.get $~lib/memory/__stack_pointer
   global.get $~lib/memory/__data_end
@@ -538,6 +542,7 @@
  (func $assert-nonnull/testRet (type $i32_=>_i32) (param $fn i32) (result i32)
   (local $1 i32)
   (local $2 i32)
+  (local $3 i32)
   global.get $~lib/memory/__stack_pointer
   i32.const 4
   i32.sub
@@ -550,8 +555,55 @@
   i32.const 0
   global.set $~argumentsLength
   local.get $fn
+  local.tee $1
+  if (result i32)
+   local.get $1
+  else
+   i32.const 32
+   i32.const 96
+   i32.const 44
+   i32.const 10
+   call $~lib/builtins/abort
+   unreachable
+  end
   i32.load $0
   call_indirect $0 (type $none_=>_i32)
+  local.tee $2
+  i32.store $0
+  local.get $2
+  if (result i32)
+   local.get $2
+  else
+   i32.const 32
+   i32.const 96
+   i32.const 44
+   i32.const 10
+   call $~lib/builtins/abort
+   unreachable
+  end
+  local.set $3
+  global.get $~lib/memory/__stack_pointer
+  i32.const 4
+  i32.add
+  global.set $~lib/memory/__stack_pointer
+  local.get $3
+ )
+ (func $assert-nonnull/testObjFn (type $i32_=>_i32) (param $foo i32) (result i32)
+  (local $1 i32)
+  (local $2 i32)
+  global.get $~lib/memory/__stack_pointer
+  i32.const 4
+  i32.sub
+  global.set $~lib/memory/__stack_pointer
+  call $~stack_check
+  global.get $~lib/memory/__stack_pointer
+  i32.const 0
+  i32.store $0
+  i32.const 0
+  global.set $~argumentsLength
+  global.get $~lib/memory/__stack_pointer
+  local.get $foo
+  call $assert-nonnull/Foo#get:baz
   local.tee $1
   i32.store $0
   local.get $1
@@ -560,11 +612,13 @@
   else
    i32.const 32
    i32.const 96
-   i32.const 44
+   i32.const 48
    i32.const 10
    call $~lib/builtins/abort
    unreachable
   end
+  i32.load $0
+  call_indirect $0 (type $none_=>_i32)
   local.set $2
   global.get $~lib/memory/__stack_pointer
   i32.const 4
@@ -575,21 +629,21 @@
  (func $assert-nonnull/testObjRet (type $i32_=>_i32) (param $foo i32) (result i32)
   (local $1 i32)
   (local $2 i32)
+  (local $3 i32)
   global.get $~lib/memory/__stack_pointer
-  i32.const 4
+  i32.const 8
   i32.sub
   global.set $~lib/memory/__stack_pointer
   call $~stack_check
   global.get $~lib/memory/__stack_pointer
-  i32.const 0
-  i32.store $0
+  i64.const 0
+  i64.store $0
   global.get $~lib/memory/__stack_pointer
   i32.const 0
   global.set $~argumentsLength
+  global.get $~lib/memory/__stack_pointer
   local.get $foo
   call $assert-nonnull/Foo#get:baz
-  i32.load $0
-  call_indirect $0 (type $none_=>_i32)
   local.tee $1
   i32.store $0
   local.get $1
@@ -603,12 +657,27 @@
    call $~lib/builtins/abort
    unreachable
   end
-  local.set $2
+  i32.load $0
+  call_indirect $0 (type $none_=>_i32)
+  local.tee $2
+  i32.store $0 offset=4
+  local.get $2
+  if (result i32)
+   local.get $2
+  else
+   i32.const 32
+   i32.const 96
+   i32.const 52
+   i32.const 10
+   call $~lib/builtins/abort
+   unreachable
+  end
+  local.set $3
   global.get $~lib/memory/__stack_pointer
-  i32.const 4
+  i32.const 8
   i32.add
   global.set $~lib/memory/__stack_pointer
-  local.get $2
+  local.get $3
  )
  (func $export:assert-nonnull/testVar (type $i32_=>_i32) (param $0 i32) (result i32)
   (local $1 i32)