1 files changed, 91 insertions, 0 deletions
diff --git a/src/Ryujinx.HLE/HOS/Tamper/CodeEmitters/EndConditionalBlock.cs b/src/Ryujinx.HLE/HOS/Tamper/CodeEmitters/EndConditionalBlock.cs
new file mode 100644
index 00000000..a25dddde
--- /dev/null
+++ b/src/Ryujinx.HLE/HOS/Tamper/CodeEmitters/EndConditionalBlock.cs
@@ -0,0 +1,91 @@
+using Ryujinx.HLE.Exceptions;
+using Ryujinx.HLE.HOS.Tamper.Conditions;
+using Ryujinx.HLE.HOS.Tamper.Operations;
+using System.Collections.Generic;
+
+namespace Ryujinx.HLE.HOS.Tamper.CodeEmitters
+{
+    /// <summary>
+    /// Code type 2 marks the end of a conditional block (started by Code Type 1, Code Type 8 or Code Type C0).
+    /// </summary>
+    class EndConditionalBlock
+    {
+        const int TerminationTypeIndex = 1;
+
+        private const byte End  = 0; // True end of the conditional.
+        private const byte Else = 1; // End of the 'then' block and beginning of 'else' block.
+
+        public static void Emit(byte[] instruction, CompilationContext context)
+        {
+            Emit(instruction, context, null);
+        }
+
+        private static void Emit(byte[] instruction, CompilationContext context, IEnumerable<IOperation> operationsElse)
+        {
+            // 2X000000
+            // X: End type (0 = End, 1 = Else).
+
+            byte terminationType = instruction[TerminationTypeIndex];
+
+            switch (terminationType)
+            {
+                case End:
+                    break;
+                case Else:
+                    // Start a new operation block with the 'else' instruction to signal that there is the 'then' block just above it.
+                    context.BlockStack.Push(new OperationBlock(instruction));
+                    return;
+                default:
+                    throw new TamperCompilationException($"Unknown conditional termination type {terminationType}");
+            }
+
+            // Use the conditional begin instruction stored in the stack.
+            var upperInstruction = context.CurrentBlock.BaseInstruction;
+            CodeType codeType = InstructionHelper.GetCodeType(upperInstruction);
+
+            // Pop the current block of operations from the stack so control instructions
+            // for the conditional can be emitted in the upper block.
+            IEnumerable<IOperation> operations = context.CurrentOperations;
+            context.BlockStack.Pop();
+
+            // If the else operations are already set, then the upper block must not be another end.
+            if (operationsElse != null && codeType == CodeType.EndConditionalBlock)
+            {
+                throw new TamperCompilationException($"Expected an upper 'if' conditional instead of 'end conditional'");
+            }
+
+            ICondition condition;
+
+            switch (codeType)
+            {
+                case CodeType.BeginMemoryConditionalBlock:
+                    condition = MemoryConditional.Emit(upperInstruction, context);
+                    break;
+                case CodeType.BeginKeypressConditionalBlock:
+                    condition = KeyPressConditional.Emit(upperInstruction, context);
+                    break;
+                case CodeType.BeginRegisterConditionalBlock:
+                    condition = RegisterConditional.Emit(upperInstruction, context);
+                    break;
+                case CodeType.EndConditionalBlock:
+                    terminationType = upperInstruction[TerminationTypeIndex];
+                    // If there is an end instruction above then it must be an else.
+                    if (terminationType != Else)
+                    {
+                        throw new TamperCompilationException($"Expected an upper 'else' conditional instead of {terminationType}");
+                    }
+                    // Re-run the Emit with the else operations set.
+                    Emit(instruction, context, operations);
+                    return;
+                default:
+                    throw new TamperCompilationException($"Conditional end does not match code type {codeType} in Atmosphere cheat");
+            }
+
+            // Create a conditional block with the current operations and nest it in the upper
+            // block of the stack.
+
+            IfBlock block = new IfBlock(condition, operations, operationsElse);
+            context.CurrentOperations.Add(block);
+        }
+    }
+}