[mono-corelib] Throw exception on an invalid use of short form opcode…

…s for locals. (dotnet#2201)
richardsonjf · Jan 27, 2020 · db70456 · db70456
1 parent 6f6c94d
commit db70456
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Showing 2 changed files with 3 additions and 1 deletion.
diff --git a/src/mono/netcore/CoreFX.issues.rsp b/src/mono/netcore/CoreFX.issues.rsp
@@ -183,7 +183,6 @@
 -noclass System.Reflection.Emit.Tests.CustomAttributeBuilderTests
 -nomethod System.Reflection.Emit.Tests.SignatureHelperAddArgument.*
 -nomethod System.Reflection.Emit.Tests.SignatureHelperGetPropertySigHelper.*
--nomethod System.Reflection.Emit.Tests.ILGeneratorEmit3.Emit_OpCodes_LocalBuilder_TooManyLocals_ThrowsInvalidOperationException
 -nomethod System.Reflection.Emit.Tests.ILGeneratorEmit3.Emit_OpCodes_LocalBuilder_LocalFromDifferentMethod_ThrowsArgumentException
 -nomethod System.Reflection.Emit.Tests.ILGeneratorDeclareLocal.DeclareLocal_TypeCreated_ThrowsInvalidOperationException
 -nomethod System.Reflection.Emit.Tests.ILGeneratorDeclareLocal.DeclareLocal_GlobalFunctionsCreated_ThrowsInvalidOperationException

diff --git a/src/mono/netcore/System.Private.CoreLib/src/System/Reflection/Emit/ILGenerator.Mono.cs b/src/mono/netcore/System.Private.CoreLib/src/System/Reflection/Emit/ILGenerator.Mono.cs
@@ -645,6 +645,9 @@ public virtual void Emit (OpCode opcode, LocalBuilder local)
 				throw new ArgumentException ("Trying to emit a local from a different ILGenerator.");
 
 			uint pos = local.position;
+			if ((opcode == OpCodes.Ldloca_S || opcode == OpCodes.Ldloc_S || opcode == OpCodes.Stloc_S) && pos > 255)
+				throw new InvalidOperationException ("Opcodes using a short-form index cannot address a local position over 255.");
+
 			bool load_addr = false;
 			bool is_store = false;
 			bool is_load = false;