Bug 21805 - Inaccurate CS0165 "Use of unassigned local variable" when using switch statement with enum constant
Summary: Inaccurate CS0165 "Use of unassigned local variable" when using switch statem...
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: 2014-08-04 20:02 UTC by Brendan Zagaeski (Xamarin Team, assistant)
Modified: 2014-09-29 22:36 UTC (History)
2 users (show)

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

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Status:
RESOLVED FIXED

Description Brendan Zagaeski (Xamarin Team, assistant) 2014-08-04 20:02:21 UTC
Inaccurate CS0165 "Use of unassigned local variable" when using switch statement with enum constant.

This might be related to the fix for https://bugzilla.xamarin.com/show_bug.cgi?id=11526. The test case on that bug works correctly on the current `mcs`.


## Steps to reproduce

Compile the following program using `mcs`:


using System;

public enum Foo { One, Two };

class MainClass
{
    private const Foo foo = Foo.Two;

    public static void Main(string[] args)
    {
        object obj;

        switch (foo)
        {
            case Foo.One:
                obj = new object();
                break;
            case Foo.Two:
                obj = new object();
                break;
        }

        Console.WriteLine(obj.ToString());
    }
}



## Result with `mcs`
> $ mcs Program.cs
> Program.cs(15,13): warning CS0162: Unreachable code detected
> Program.cs(23,27): error CS0165: Use of unassigned local variable `obj'
> Compilation failed: 1 error(s), 1 warnings


## Result with `csc`

> C:\>csc Program.cs
> Microsoft (R) Visual C# Compiler version 12.0.30501.0
> for C# 5
> Copyright (C) Microsoft Corporation. All rights reserved.
> 
> Program.cs(16,17): warning CS0162: Unreachable code detected


## Version information

Tested with Mono 3.6.0 (no/f540f8a) and Mono 3.6.1 (master/2111224)
Comment 1 Marek Safar 2014-08-06 03:53:29 UTC
Fixed in master