Implement rethrowing

GerardSmit · GerardSmit · commit f132d539d476 · 2022-12-28T19:02:07.000+01:00
diff --git a/WebAssembly.Tests/Instructions/CatchTests.cs b/WebAssembly.Tests/Instructions/CatchTests.cs
@@ -1,3 +1,4 @@
+using System;
 using Microsoft.VisualStudio.TestTools.UnitTesting;
 
 namespace WebAssembly.Instructions;
@@ -129,4 +130,52 @@ public void Catch_MultipleExceptionTags()
             }
         ).Test());
     }
+
+
+    /// <summary>
+    /// Tests compilation and execution of the <see cref="Rethrow"/> instruction.
+    /// </summary>
+    [TestMethod]
+    public void Catch_TryInCatch()
+    {
+        Assert.AreEqual(1, AssemblyBuilder.CreateInstance<dynamic>("Test", WebAssemblyValueType.Int32,
+            new Instruction[]
+            {
+                new Try(),
+
+                    new Throw(0),
+
+                new Catch(0),
+
+                    new Try(),
+                        new Throw(1),
+                    new Catch(1),
+                        new Int32Constant(1),
+                        new Return(),
+                    new End(),
+
+                new End(),
+
+                new Int32Constant(0),
+                new End()
+            },
+            module =>
+            {
+                module.Types.Add(new WebAssemblyType
+                {
+                    Parameters = Array.Empty<WebAssemblyValueType>()
+                });
+
+                module.Tags.Add(new WebAssemblyTag
+                {
+                    TypeIndex = 1
+                });
+
+                module.Tags.Add(new WebAssemblyTag
+                {
+                    TypeIndex = 1
+                });
+            }
+        ).Test());
+    }
 }
diff --git a/WebAssembly.Tests/Instructions/RethrowTests.cs b/WebAssembly.Tests/Instructions/RethrowTests.cs
@@ -0,0 +1,48 @@
+using System;
+using Microsoft.VisualStudio.TestTools.UnitTesting;
+using WebAssembly.Runtime;
+
+namespace WebAssembly.Instructions;
+
+/// <summary>
+/// Tests the <see cref="Rethrow"/> instruction.
+/// </summary>
+[TestClass]
+public class RethrowTests
+{
+    /// <summary>
+    /// Tests compilation and execution of the <see cref="Rethrow"/> instruction.
+    /// </summary>
+    [TestMethod]
+    public void Rethrow_Exception()
+    {
+        Assert.ThrowsException<WebAssemblyException>(() =>
+        {
+            AssemblyBuilder.CreateInstance<dynamic>("Test", WebAssemblyValueType.Int32,
+                new Instruction[]
+                {
+                    new Try(),
+                    new Throw(0),
+                    new Catch(0),
+                    new Rethrow(0),
+                    new End(),
+
+                    new Int32Constant(0),
+                    new End()
+                },
+                module =>
+                {
+                    module.Types.Add(new WebAssemblyType
+                    {
+                        Parameters = Array.Empty<WebAssemblyValueType>()
+                    });
+
+                    module.Tags.Add(new WebAssemblyTag
+                    {
+                        TypeIndex = 1
+                    });
+                }
+            ).Test();
+        });
+    }
+}
diff --git a/WebAssembly.Tests/Instructions/TryTests.cs b/WebAssembly.Tests/Instructions/TryTests.cs
@@ -8,5 +8,36 @@ namespace WebAssembly.Instructions;
 [TestClass]
 public class TryTests
 {
-    // Dummy type
+    /// <summary>
+    /// Tests compilation and execution of the <see cref="Catch"/> instruction when there are no exceptions.
+    /// </summary>
+    [TestMethod]
+    public void Try_ReturnValue()
+    {
+        Assert.AreEqual<int>(0, AssemblyBuilder.CreateInstance<dynamic>("Test", WebAssemblyValueType.Int32,
+            new Instruction[]
+            {
+                new Try(BlockType.Int32),
+                new Int32Constant(0),
+                new Catch(0),
+                new End(),
+                new End()
+            },
+            module =>
+            {
+                module.Types.Add(new WebAssemblyType
+                {
+                    Parameters = new[]
+                    {
+                        WebAssemblyValueType.Int32
+                    },
+                });
+
+                module.Tags.Add(new WebAssemblyTag
+                {
+                    TypeIndex = 1
+                });
+            }
+        ).Test());
+    }
 }
diff --git a/WebAssembly.Tests/Runtime/SpecTestData/rethrow/rethrow.0.wasm b/WebAssembly.Tests/Runtime/SpecTestData/rethrow/rethrow.0.wasm
diff --git a/WebAssembly.Tests/Runtime/SpecTestData/rethrow/rethrow.1.wasm b/WebAssembly.Tests/Runtime/SpecTestData/rethrow/rethrow.1.wasm
diff --git a/WebAssembly.Tests/Runtime/SpecTestData/rethrow/rethrow.2.wasm b/WebAssembly.Tests/Runtime/SpecTestData/rethrow/rethrow.2.wasm
diff --git a/WebAssembly.Tests/Runtime/SpecTestData/rethrow/rethrow.3.wasm b/WebAssembly.Tests/Runtime/SpecTestData/rethrow/rethrow.3.wasm
diff --git a/WebAssembly.Tests/Runtime/SpecTestData/rethrow/rethrow.json b/WebAssembly.Tests/Runtime/SpecTestData/rethrow/rethrow.json
@@ -0,0 +1,18 @@
+{"source_filename": "rethrow.wast",
+ "commands": [
+  {"type": "module", "line": 3, "filename": "rethrow.0.wasm"}, 
+  {"type": "assert_exception", "line": 75, "action": {"type": "invoke", "field": "catch-rethrow-0", "args": []}, "expected": []}, 
+  {"type": "assert_exception", "line": 77, "action": {"type": "invoke", "field": "catch-rethrow-1", "args": [{"type": "i32", "value": "0"}]}, "expected": [{"type": "i32"}]}, 
+  {"type": "assert_return", "line": 78, "action": {"type": "invoke", "field": "catch-rethrow-1", "args": [{"type": "i32", "value": "1"}]}, "expected": [{"type": "i32", "value": "23"}]}, 
+  {"type": "assert_exception", "line": 80, "action": {"type": "invoke", "field": "catchall-rethrow-0", "args": []}, "expected": []}, 
+  {"type": "assert_exception", "line": 82, "action": {"type": "invoke", "field": "catchall-rethrow-1", "args": [{"type": "i32", "value": "0"}]}, "expected": [{"type": "i32"}]}, 
+  {"type": "assert_return", "line": 83, "action": {"type": "invoke", "field": "catchall-rethrow-1", "args": [{"type": "i32", "value": "1"}]}, "expected": [{"type": "i32", "value": "23"}]}, 
+  {"type": "assert_exception", "line": 84, "action": {"type": "invoke", "field": "rethrow-nested", "args": [{"type": "i32", "value": "0"}]}, "expected": [{"type": "i32"}]}, 
+  {"type": "assert_exception", "line": 85, "action": {"type": "invoke", "field": "rethrow-nested", "args": [{"type": "i32", "value": "1"}]}, "expected": [{"type": "i32"}]}, 
+  {"type": "assert_return", "line": 86, "action": {"type": "invoke", "field": "rethrow-nested", "args": [{"type": "i32", "value": "2"}]}, "expected": [{"type": "i32", "value": "23"}]}, 
+  {"type": "assert_return", "line": 88, "action": {"type": "invoke", "field": "rethrow-recatch", "args": [{"type": "i32", "value": "0"}]}, "expected": [{"type": "i32", "value": "23"}]}, 
+  {"type": "assert_return", "line": 89, "action": {"type": "invoke", "field": "rethrow-recatch", "args": [{"type": "i32", "value": "1"}]}, "expected": [{"type": "i32", "value": "42"}]}, 
+  {"type": "assert_exception", "line": 91, "action": {"type": "invoke", "field": "rethrow-stack-polymorphism", "args": []}, "expected": []}, 
+  {"type": "assert_invalid", "line": 93, "filename": "rethrow.1.wasm", "text": "invalid rethrow label", "module_type": "binary"}, 
+  {"type": "assert_invalid", "line": 94, "filename": "rethrow.2.wasm", "text": "invalid rethrow label", "module_type": "binary"}, 
+  {"type": "assert_invalid", "line": 95, "filename": "rethrow.3.wasm", "text": "invalid rethrow label", "module_type": "binary"}]}
diff --git a/WebAssembly.Tests/Runtime/SpecTests.cs b/WebAssembly.Tests/Runtime/SpecTests.cs
@@ -948,4 +948,20 @@ public void SpecTest_throw()
 
         SpecTestRunner.Run(Path.Combine("Runtime", "SpecTestData", "throw"), "throw.json", skips.Contains);
     }
+
+    /// <summary>
+    /// Runs the switch tests.
+    /// </summary>
+    [TestMethod]
+    public void SpecTest_rethrow()
+    {
+        var skips = new HashSet<uint>
+        {
+            93, // TODO: Validate invalid rethrow
+            94, // TODO: Validate invalid rethrow
+            95, // TODO: Validate invalid rethrow
+        };
+
+        SpecTestRunner.Run(Path.Combine("Runtime", "SpecTestData", "rethrow"), "rethrow.json", skips.Contains);
+    }
 }
diff --git a/WebAssembly/Instruction.cs b/WebAssembly/Instruction.cs
@@ -133,6 +133,7 @@ internal static IEnumerable<Instruction> Parse(Reader reader)
                     depth++;
                     break;
 
+                case OpCode.Rethrow: yield return new Rethrow(reader); break;
                 case OpCode.Throw: yield return new Throw(reader); break;
                 case OpCode.Catch: yield return new Catch(reader); break;
                 case OpCode.CatchAll: yield return new CatchAll(); break;
diff --git a/WebAssembly/Instructions/Catch.cs b/WebAssembly/Instructions/Catch.cs
@@ -36,34 +36,7 @@ internal Catch(Reader reader)
 
     internal sealed override void Compile(CompilationContext context)
     {
-        var tag = context.Tags?[Index];
-
-        if (tag is null)
-        {
-            throw new InvalidOperationException($"Tag {Index} not found.");
-        }
-
-        var type = context.Types?[tag.TypeIndex];
-
-        if (type is null)
-        {
-            throw new InvalidOperationException($"Type {tag.TypeIndex} not found.");
-        }
-
-        var depth = checked((uint)context.Depth.Count - 1);
-        var label = context.Labels[depth];
-
-        if (!context.ExceptionLabels.Contains(label))
-        {
-            throw new InvalidOperationException("CatchAll must be inside a try block");
-        }
-
         context.BeginCatchBlock(Index);
         context.MarkReachable();
-
-        foreach (var parameterType in type.RawParameterTypes)
-        {
-            context.Stack.Push(parameterType);
-        }
     }
 }
diff --git a/WebAssembly/Instructions/Rethrow.cs b/WebAssembly/Instructions/Rethrow.cs
@@ -0,0 +1,43 @@
+using System;
+using System.Reflection.Emit;
+using WebAssembly.Runtime.Compilation;
+
+namespace WebAssembly.Instructions;
+
+/// <summary>
+/// The beginning of an Rethrow.
+/// </summary>
+public class Rethrow : TagInstruction
+{
+    /// <summary>
+    /// Always <see cref="WebAssembly.OpCode.Rethrow"/>.
+    /// </summary>
+    public sealed override OpCode OpCode => OpCode.Rethrow;
+
+    /// <summary>
+    /// Creates a new  <see cref="Rethrow"/> instance.
+    /// </summary>
+    public Rethrow()
+    {
+    }
+
+    /// <summary>
+    /// Creates a new <see cref="Throw"/> instance.
+    /// </summary>
+    /// <param name="relativeDepth">The relative depth of the exception to rethrow.</param>
+    public Rethrow(uint relativeDepth)
+        : base(relativeDepth)
+    {
+    }
+
+    internal Rethrow(Reader reader)
+        : base(reader)
+    {
+    }
+
+    internal sealed override void Compile(CompilationContext context)
+    {
+        context.Rethrow();
+        context.MarkUnreachable();
+    }
+}
diff --git a/WebAssembly/Instructions/Throw.cs b/WebAssembly/Instructions/Throw.cs
@@ -1,5 +1,4 @@
-﻿using System;
-using System.Linq;
+﻿using System.Linq;
 using System.Reflection.Emit;
 using WebAssembly.Runtime.Compilation;
 
@@ -38,11 +37,7 @@ internal Throw(Reader reader)
 
     internal sealed override void Compile(CompilationContext context)
     {
-        var tag = context.Tags?[this.Index] ?? throw new InvalidOperationException($"Tag {this.Index} not found.");
-        var type = context.Types?[tag.TypeIndex] ?? throw new InvalidOperationException($"Type {tag.TypeIndex} not found.");
-
-        if (tag == null)
-            throw new InvalidOperationException($"Type index {this.Index} not found.");
+        var type = context.GetTagType(this.Index);
 
         var exceptionType = type.ToException();
         var constructor = exceptionType.GetConstructors().Single();
diff --git a/WebAssembly/Instructions/Try.cs b/WebAssembly/Instructions/Try.cs
@@ -37,7 +37,7 @@ internal Try(Reader reader)
 
     internal sealed override void Compile(CompilationContext context)
     {
-        var label = context.BeginExceptionBlock();
+        var label = context.BeginExceptionBlock(Type);
         context.ExceptionLabels.Add(label);
         context.Labels.Add(checked((uint)context.Depth.Count), label);
         context.Depth.Push(this);
diff --git a/WebAssembly/Runtime/Compilation/CompilationContext.cs b/WebAssembly/Runtime/Compilation/CompilationContext.cs
