Add conditional expressions to compiler

ctowasm/src/parser/c-ast/core.ts

@@ -16,6 +16,7 @@ import FunctionDefinition from "~src/parser/c-ast/functionDefinition";
 import Block from "~src/parser/c-ast/statement/compoundStatement";
 import IdentifierExpression from "~src/parser/c-ast/expression/identifierExpr";
 import { ModuleName } from "~src/modules";
+import ConditionalExpression from "~src/parser/c-ast/expression/conditionalExpression";
 
 export interface CNodeBase {
   type: string;
@@ -49,7 +50,8 @@ export type Expression =
   | Constant
   | IdentifierExpression
   | UnaryExpression
-  | CommaSeparatedExpressions;
+  | CommaSeparatedExpressions
+  | ConditionalExpression;
 
 export interface CommaSeparatedExpressions extends CNodeBase {
   type: "CommaSeparatedExpressions";

ctowasm/src/processor/c-ast/core.ts

@@ -9,6 +9,7 @@ import { ScalarCDataType } from "~src/common/types";
 import { ConstantP } from "~src/processor/c-ast/expression/constants";
 import {
   BinaryExpressionP,
+  ConditionalExpressionP,
   PostStatementExpressionP,
   PreStatementExpressionP,
   UnaryExpressionP,
@@ -23,6 +24,7 @@ import { SelectionStatementP } from "~src/processor/c-ast/statement/selectionSta
 import { JumpStatementP } from "~src/processor/c-ast/statement/jumpStatement";
 import { PrimaryDataTypeMemoryObjectDetails } from "~src/processor/dataTypeUtil";
 import { ModuleName } from "~src/modules";
+import ConditionalExpression from "~src/parser/c-ast/expression/conditionalExpression";
 
 export type CNodeP = FunctionDefinitionP | StatementP | ExpressionP;
 
@@ -49,7 +51,8 @@ export type ExpressionP =
   | PostStatementExpressionP
   | UnaryExpressionP
   | Address
-  | MemoryLoad;
+  | MemoryLoad
+  | ConditionalExpressionP;
 
 /**
  * All expressions should inherit this, as all expressions should have a primary data type.

ctowasm/src/processor/c-ast/expression/expressions.ts

@@ -20,15 +20,6 @@ export interface UnaryExpressionP extends ExpressionPBase {
   expr: ExpressionP;
 }
 
-/**
- * Wrapper node that indicates that the wrapped expression is to be treated as a boolean (int that is 1 or 0)
- */
-export interface BooleanExpressionP extends ExpressionPBase {
-  type: "BooleanExpression";
-  expr: ExpressionP;
-  dataType: "signed int";
-}
-
 /**
  * Represents an expression that consists of a series of statements followed by a expression
  * Used as the result of processing assignment expressions.
@@ -49,6 +40,16 @@ export interface PostStatementExpressionP extends ExpressionPBase {
   expr: ExpressionP;
 }
 
+/**
+ * Represents a inline conditional expression e.g: 1 ? 2 : 3
+ */
+export interface ConditionalExpressionP extends ExpressionPBase {
+  type: "ConditionalExpression";
+  condition: ExpressionP;
+  trueExpression: ExpressionP; // expression to return if condition is not zero (true)
+  falseExpression: ExpressionP;
+}
+
 /**
  * A wrapper for the result of processing expressions, to be used by the processor only (not present in generated AST)
  */

ctowasm/src/processor/expressionUtil.ts

@@ -107,6 +107,16 @@ export function checkBinaryExpressionDataTypesValidity(
   }
 }
 
+/**
+ * Determine the overall datatype of a ConditionalExpression (e.g. 1 ? 2 : 3).
+ * Follows same rules as binary expressions ("+" used as placeholder).
+ */
+export function determineConditionalExpressionDataType(leftExprDataType: ScalarDataType,
+  rightExprDataType: ScalarDataType) {
+    const dataType = determineResultDataTypeOfBinaryExpression(leftExprDataType, rightExprDataType, "+");
+    return dataType.type === "pointer" ? "pointer" : dataType.primaryDataType;
+}
+
 /**
  * Determines the type that operands in a binary expression should be converted to before the operation,
  * according to rules of arithemetic conversion 6.3.1.8 in C17 standard.