dotnet/roslyn

Compiler should report CS0208 - "Cannot declare pointer to a managed object" when managed object pointer is returned from IL with type inferrence

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#33,041 建立於 2019年2月1日

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Area-CompilersBughelp wanted

描述

Version Used: C# 7.2

Steps to Reproduce:

  1. Have this IL and compile it
.method public hidebysig static !!0* GetPointer<T>(
      !!0 'value'
    ) cil managed
{
    ldarga 0
    conv.u
    ret
}
  1. Call it from C# as such
object obj = new object();
var objPtr = <something>.GetPointer(obj);

Expected Behavior: CS0208 - "Cannot declare pointer to a managed object"

[or, a bit more of a stretch, allow managed type pointers, such as Exception*]

Actual Behavior: Compiles and behaves like an actual object reference pointer. So objPtr->GetType() is legal and runs IMPORTANT: This only works with that type inferrence, Without var it doesn't compile

貢獻者指南

技術棧
csharp
領域
tooling
議題類型
bug
難度面向新貢獻者的預計實作難度，1 表示很小改動，5 表示專家級工作。
5
預計時間有經驗貢獻者完成調查、實作、測試並準備 pull request 的粗略時間範圍。
3-5 days
活動狀態議題目前的可參與程度：新鮮、活躍、陳舊、阻塞或等待維護者輸入。
stale
清晰度議題是否清楚說明預期改動、驗收標準和下一步。
clear
前置要求
C# pointers and managed typesIntermediate Language (IL)Roslyn compiler's method return type handling
新手友善度1-100 的估計分數，表示該議題對首次貢獻者的友善程度。
15
研究方向
Investigate the Roslyn compiler's handling of methods returning pointers from IL with type inference (var). Look into the Binder or type inference logic for generic methods defined in IL, specifically the 'GetPointer<T>' method. The CS0208 error should be triggered when a managed type is used with a pointer. Relevant files may include Binder Unsafe.cs or Conversions.cs, and the IL parser's handling of generic signatures.