fix: improve null comarasion

AssemblyScript · Oct 7, 2023 · 7457a31 · 7457a31
1 parent e3e4166
commit 7457a31
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Showing 6 changed files with 909 additions and 23 deletions.
diff --git a/src/compiler.ts b/src/compiler.ts
@@ -111,7 +111,6 @@ import {
 
 import {
   Token,
-  operatorTokenToString
 } from "./tokenizer";
 
 import {
@@ -3946,7 +3945,10 @@ export class Compiler extends DiagnosticEmitter {
 
       case Token.Equals_Equals_Equals:
       case Token.Equals_Equals: {
-        leftExpr = this.compileExpression(left, contextualType);
+        commonType = this.resolver.resolveCompareExpressionCommonType(expression, this.currentFlow);
+        if (!commonType) return module.unreachable();
+
+        leftExpr = this.compileExpression(left, commonType);
         leftType = this.currentType;
 
         // check operator overload
@@ -3959,17 +3961,9 @@ export class Compiler extends DiagnosticEmitter {
           }
         }
 
-        rightExpr = this.compileExpression(right, leftType);
+        rightExpr = this.compileExpression(right, commonType);
         rightType = this.currentType;
-        commonType = Type.commonType(leftType, rightType, contextualType);
-        if (!commonType) {
-          this.error(
-            DiagnosticCode.Operator_0_cannot_be_applied_to_types_1_and_2,
-            expression.range, operatorTokenToString(expression.operator), leftType.toString(), rightType.toString()
-          );
-          this.currentType = contextualType;
-          return module.unreachable();
-        }
+
         if (commonType.isFloatValue) {
           if (
             isConstExpressionNaN(module, rightExpr) ||
@@ -3998,9 +3992,13 @@ export class Compiler extends DiagnosticEmitter {
       }
       case Token.Exclamation_Equals_Equals:
       case Token.Exclamation_Equals: {
-        leftExpr = this.compileExpression(left, contextualType);
+        commonType = this.resolver.resolveCompareExpressionCommonType(expression, this.currentFlow);
+        if (!commonType) return module.unreachable();
+
+        leftExpr = this.compileExpression(left, commonType);
         leftType = this.currentType;
 
+
         // check operator overload
         let classReference = leftType.getClass();
         if (classReference) {
@@ -4011,17 +4009,9 @@ export class Compiler extends DiagnosticEmitter {
           }
         }
 
-        rightExpr = this.compileExpression(right, leftType);
+        rightExpr = this.compileExpression(right, commonType);
         rightType = this.currentType;
-        commonType = Type.commonType(leftType, rightType, contextualType);
-        if (!commonType) {
-          this.error(
-            DiagnosticCode.Operator_0_cannot_be_applied_to_types_1_and_2,
-            expression.range, operatorTokenToString(expression.operator), leftType.toString(), rightType.toString()
-          );
-          this.currentType = contextualType;
-          return module.unreachable();
-        }
+
         if (commonType.isFloatValue) {
           if (
             isConstExpressionNaN(module, rightExpr) ||

diff --git a/src/resolver.ts b/src/resolver.ts
@@ -1061,6 +1061,37 @@ export class Resolver extends DiagnosticEmitter {
     return null;
   }
 
+  resolveCompareExpressionCommonType(
+    /** The expression to resolve. */
+    expression: BinaryExpression,
+    /** Contextual flow. */
+    ctxFlow: Flow
+  ): Type | null {
+    const left = expression.left;
+    const right = expression.right;
+
+    const leftType = this.resolveExpression(left, ctxFlow, Type.auto, ReportMode.Report);
+    if (!leftType) return null;
+    const rightType = this.resolveExpression(right, ctxFlow, Type.auto, ReportMode.Report);
+    if (!rightType) return null;
+
+    if (left.kind == NodeKind.Null && rightType.isReference) {
+      return rightType.asNullable();
+    }
+    if (right.kind == NodeKind.Null && leftType.isReference) {
+      return leftType.asNullable();
+    }
+
+    const commonType = Type.commonType(leftType, rightType, Type.auto);
+    if (!commonType) {
+      this.error(
+        DiagnosticCode.Operator_0_cannot_be_applied_to_types_1_and_2,
+        expression.range, operatorTokenToString(expression.operator), leftType.toString(), rightType.toString()
+      );
+    }
+    return commonType;
+  }
+
   /** resolving expressions */
   private resolvingExpressions: Set<Expression> = new Set();