From 3c9a0d8a41dc8240840de03d991753f5fc488495 Mon Sep 17 00:00:00 2001
From: Siegfried Pammer <siegfriedpammer@gmail.com>
Date: Sat, 23 Sep 2017 19:56:38 +0200
Subject: [PATCH] Ad #866: No longer use Debug.Assert, but add warnings to AST.

---
 ICSharpCode.Decompiler/CSharp/CSharpDecompiler.cs    |  6 ++++++
 ICSharpCode.Decompiler/CSharp/ExpressionBuilder.cs   |  7 ++++++-
 ICSharpCode.Decompiler/IL/ILReader.cs                |  4 +++-
 ICSharpCode.Decompiler/IL/Instructions/ILFunction.cs | 11 +++++++++++
 4 files changed, 26 insertions(+), 2 deletions(-)

diff --git a/ICSharpCode.Decompiler/CSharp/CSharpDecompiler.cs b/ICSharpCode.Decompiler/CSharp/CSharpDecompiler.cs
index 5b7876ab1..3ad5d70ed 100644
--- a/ICSharpCode.Decompiler/CSharp/CSharpDecompiler.cs
+++ b/ICSharpCode.Decompiler/CSharp/CSharpDecompiler.cs
@@ -663,6 +663,12 @@ namespace ICSharpCode.Decompiler.CSharp
 			AddDefinesForConditionalAttributes(function);
 			var statementBuilder = new StatementBuilder(specializingTypeSystem, decompilationContext, method, function, settings, CancellationToken);
 			var body = statementBuilder.ConvertAsBlock(function.Body);
+
+			Comment prev = null;
+			foreach (string warning in function.Warnings) {
+				body.InsertChildAfter(prev, prev = new Comment(warning), Roles.Comment);
+			}
+
 			entityDecl.AddChild(body, Roles.Body);
 
 			if (function.IsIterator) {
diff --git a/ICSharpCode.Decompiler/CSharp/ExpressionBuilder.cs b/ICSharpCode.Decompiler/CSharp/ExpressionBuilder.cs
index e18fd8b96..634572b1d 100644
--- a/ICSharpCode.Decompiler/CSharp/ExpressionBuilder.cs
+++ b/ICSharpCode.Decompiler/CSharp/ExpressionBuilder.cs
@@ -1009,7 +1009,12 @@ namespace ICSharpCode.Decompiler.CSharp
 			var body = builder.ConvertAsBlock(function.Body);
 			bool isLambda = false;
 			bool isMultiLineLambda = false;
-			
+
+			Comment prev = null;
+			foreach (string warning in function.Warnings) {
+				body.InsertChildAfter(prev, prev = new Comment(warning), Roles.Comment);
+			}
+
 			// if there is an anonymous type involved, we are forced to use a lambda expression.
 			if (ame.Parameters.Any(p => p.Type.IsNull)) {
 				isLambda = true;
diff --git a/ICSharpCode.Decompiler/IL/ILReader.cs b/ICSharpCode.Decompiler/IL/ILReader.cs
index e307e68bf..d98a50350 100644
--- a/ICSharpCode.Decompiler/IL/ILReader.cs
+++ b/ICSharpCode.Decompiler/IL/ILReader.cs
@@ -38,6 +38,7 @@ namespace ICSharpCode.Decompiler.IL
 		readonly IDecompilerTypeSystem typeSystem;
 
 		public bool UseDebugSymbols { get; set; }
+		public List<string> Warnings { get; } = new List<string>();
 
 		public ILReader(IDecompilerTypeSystem typeSystem)
 		{
@@ -182,7 +183,7 @@ namespace ICSharpCode.Decompiler.IL
 		/// </summary>
 		void Warn(string message)
 		{
-			Debug.Fail(string.Format("IL_{0:x4}: {1}", currentInstruction.Offset, message));
+			Warnings.Add(string.Format("IL_{0:x4}: {1}", currentInstruction.Offset, message));
 		}
 
 		void MergeStacks(ImmutableStack<ILVariable> a, ImmutableStack<ILVariable> b)
@@ -324,6 +325,7 @@ namespace ICSharpCode.Decompiler.IL
 			foreach (var c in function.Descendants.OfType<BlockContainer>()) {
 				c.SortBlocks();
 			}
+			function.Warnings.AddRange(Warnings);
 			return function;
 		}
 
diff --git a/ICSharpCode.Decompiler/IL/Instructions/ILFunction.cs b/ICSharpCode.Decompiler/IL/Instructions/ILFunction.cs
index 0616a4c50..d570ae62b 100644
--- a/ICSharpCode.Decompiler/IL/Instructions/ILFunction.cs
+++ b/ICSharpCode.Decompiler/IL/Instructions/ILFunction.cs
@@ -34,6 +34,11 @@ namespace ICSharpCode.Decompiler.IL
 		public readonly MethodDefinition Method;
 		public readonly ILVariableCollection Variables;
 
+		/// <summary>
+		/// List of warnings of ILReader.
+		/// </summary>
+		public List<string> Warnings { get; } = new List<string>();
+
 		/// <summary>
 		/// Gets whether this function is a decompiled iterator (is using yield).
 		/// This flag gets set by the YieldReturnDecompiler.
@@ -103,6 +108,12 @@ namespace ICSharpCode.Decompiler.IL
 			output.MarkFoldEnd();
 			output.WriteLine();
 			body.WriteTo(output, options);
+
+			foreach (string warning in Warnings) {
+				output.WriteLine("//" + warning);
+			}
+
+			body.WriteTo(output);
 			
 			output.WriteLine();
 			output.Unindent();