Floating point constant expression

Cesium.CodeGen.Tests/CodeGenMethodTests.cs

@@ -73,6 +73,7 @@ public void VarArgMainDoesNotCompile2() => DoesNotCompile<WipException>(
     [Fact] public Task Parameter1Get() => DoTest("int foo(int x){ return x + 1; }");
     [Fact] public Task Parameter5Get() => DoTest("int foo(int a, int b, int c, int d, int e){ return e + 1; }");
     [Fact] public Task CharConstTest() => DoTest("int main() { char x = '\\t'; return 42; }");
+    [Fact] public Task DoubleConstTest() => DoTest("int main() { double x = 1.5; return 42; }");
 
     [Fact] public Task MultiDeclaration() => DoTest("int main() { int x = 0, y = 2 + 2; }");
 

Cesium.CodeGen.Tests/CodeGenTestBase.cs

@@ -11,6 +11,7 @@
 
 namespace Cesium.CodeGen.Tests;
 
+[UseInvariantCulture]
 public abstract class CodeGenTestBase : VerifyTestBase
 {
     protected static AssemblyDefinition GenerateAssembly(TargetRuntimeDescriptor? runtime, params string[] sources)

Cesium.CodeGen.Tests/UseInvariantCultureAttribute.cs

@@ -0,0 +1,35 @@
+using System;
+using System.Globalization;
+using System.Linq;
+using System.Reflection;
+using System.Threading;
+using Xunit.Sdk;
+
+
+[AttributeUsage(AttributeTargets.Class | AttributeTargets.Method, AllowMultiple = false, Inherited = true)]
+public class UseInvariantCultureAttribute : BeforeAfterTestAttribute
+{
+    CultureInfo originalCulture = null!;
+    CultureInfo originalUICulture = null!;
+
+    public override void Before(MethodInfo methodUnderTest)
+    {
+        originalCulture = Thread.CurrentThread.CurrentCulture;
+        originalUICulture = Thread.CurrentThread.CurrentUICulture;
+
+        Thread.CurrentThread.CurrentCulture = CultureInfo.InvariantCulture;
+        Thread.CurrentThread.CurrentUICulture = CultureInfo.InvariantCulture;
+
+        CultureInfo.CurrentCulture.ClearCachedData();
+        CultureInfo.CurrentUICulture.ClearCachedData();
+    }
+
+    public override void After(MethodInfo methodUnderTest)
+    {
+        Thread.CurrentThread.CurrentCulture = originalCulture;
+        Thread.CurrentThread.CurrentUICulture = originalUICulture;
+
+        CultureInfo.CurrentCulture.ClearCachedData();
+        CultureInfo.CurrentUICulture.ClearCachedData();
+    }
+}

Cesium.CodeGen.Tests/verified/CodeGenMethodTests.DoubleConstTest.verified.txt

@@ -0,0 +1,7 @@
+System.Int32 <Module>::main()
+  Locals:
+    System.Double V_0
+  IL_0000: ldc.r8 1.5
+  IL_0009: stloc.0
+  IL_000a: ldc.i4.s 42
+  IL_000c: ret

Cesium.CodeGen/Ir/Expressions/ConstantExpression.cs

@@ -35,6 +35,7 @@ private static IConstant GetConstant(Ast.ConstantExpression expression)
             CTokenType.IntLiteral => new IntegerConstant(constant.Text),
             CTokenType.CharLiteral => new CharConstant(constant.Text),
             CTokenType.StringLiteral => new StringConstant(constant),
+            CTokenType.FloatLiteral => new FloatingPointConstant(constant.Text),
             _ => throw new WipException(228, $"Constant of kind {constant.Kind} is not supported.")
         };
     }

Cesium.CodeGen/Ir/Expressions/Constants/FloatingPointConstant.cs

@@ -0,0 +1,28 @@
+using System.Globalization;
+using Cesium.CodeGen.Contexts;
+using Cesium.CodeGen.Ir.Types;
+using Cesium.Core;
+using Mono.Cecil.Cil;
+
+namespace Cesium.CodeGen.Ir.Expressions.Constants;
+
+internal class FloatingPointConstant : IConstant
+{
+    private readonly double _value;
+
+    public FloatingPointConstant(string value)
+    {
+        if (!double.TryParse(value, NumberStyles.Float, CultureInfo.InvariantCulture.NumberFormat, out _value))
+            throw new CompilationException($"Cannot parse a double literal: {value}.");
+    }
+
+    public void EmitTo(IDeclarationScope scope)
+    {
+        // TODO[#248]: This should support `float` as well.
+        scope.Method.Body.Instructions.Add(Instruction.Create(OpCodes.Ldc_R8, _value));
+    }
+
+    public IType GetConstantType(IDeclarationScope scope) => scope.CTypeSystem.Double;
+
+    public override string ToString() => $"double: {_value}";
+}

Cesium.CodeGen/Ir/Types/CTypeSystem.cs

@@ -8,4 +8,6 @@ internal class CTypeSystem
     public IType Char { get; } = new PrimitiveType(PrimitiveTypeKind.Char);
     public IType Int { get; } = new PrimitiveType(PrimitiveTypeKind.Int);
     public IType CharPtr { get; } = new PrimitiveType(PrimitiveTypeKind.Char).MakePointerType();
+    public IType Float { get; } = new PrimitiveType(PrimitiveTypeKind.Float);
+    public IType Double { get; } = new PrimitiveType(PrimitiveTypeKind.Double);
 }