Bug 14347 - mcs doesn't generate CS0208 on pointers to type parameters
Summary: mcs doesn't generate CS0208 on pointers to type parameters
Status: RESOLVED FIXED
Alias: None
Product: Compilers
Classification: Mono
Component: C# ()
Version: unspecified
Hardware: PC Mac OS
: --- normal
Target Milestone: ---
Assignee: Marek Safar
URL:
Depends on:
Blocks:
 
Reported: 2013-08-30 10:32 UTC by Jonathan Pryor
Modified: 2013-08-30 11:51 UTC (History)
1 user (show)

Tags:
Is this bug a regression?: ---
Last known good build:

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Related Links:
Status:
RESOLVED FIXED

Description Jonathan Pryor 2013-08-30 10:32:37 UTC
Consider the following code:

  unsafe class Foo<T>
    where T : struct
  {
    public T* Elements {get {return null;}}
  }

  class Test {
    public static unsafe void Main ()
    {
    }
  }

mcs compiles it without errors.

.NET CSC errors with:

gp.cs(6,12): error CS0208: Cannot take the address of, get the size of, or
        declare a pointer to a managed type ('T')

(If `where T : struct` is removed, mcs generates the correct error.)

Furthermore, when attempting to use Foo<T>, mcs errors with CS0584/NotSupportedException:

    var f = new Foo<int>();
...
$ mcs /unsafe gp.cs --stacktrace
gp.cs(10,15): error CS0584: Internal compiler error: Operation is not supported.
	in Expression.Resolve (Mono.CSharp.ResolveContext, Mono.CSharp.ResolveFlags)
	in Expression.Resolve (Mono.CSharp.ResolveContext)
	in BlockVariable.Resolve (Mono.CSharp.BlockContext, System.Boolean)
	in BlockVariable.Resolve (Mono.CSharp.BlockContext)
	in Block.Resolve (Mono.CSharp.BlockContext)
	in ParametersBlock.Resolve (Mono.CSharp.FlowBranching, Mono.CSharp.BlockContext, Mono.CSharp.IMethodData)
	in MethodData.Emit (Mono.CSharp.TypeDefinition)
	in MethodOrOperator.Emit ()
	in Method.Emit ()
	in TypeDefinition.Emit ()
	in ClassOrStruct.Emit ()
	in Class.Emit ()
	in TypeDefinition.EmitContainer ()
	in TypeContainer.EmitContainer ()
	in NamespaceContainer.EmitContainer ()
	in TypeContainer.EmitContainer ()
	in ModuleContainer.EmitContainer ()
	in AssemblyDefinition.Emit ()
	in AssemblyDefinitionStatic.Emit ()
	in Driver.Compile ()
	in Driver.Main (System.String[])
Comment 1 Marek Safar 2013-08-30 11:51:07 UTC
Fixed in master