How to throw compilation error from an attribute?

Question

there are attributes in .NET (e.g. ObsoleteAttribute) which are able to prevent compilation or at least throw compile time warnings depending on their configuration.

How to write an attribute that is able to interfere with compilation? Is there a way to do this from outside Microsoft?

Unfortunately, the link http://msdn.microsoft.com/en-us/library/aa664620%28VS.71%29.aspx has gone stale. — O. R. Mapper, Dec 02 '19 at 09:05

score 7 · Accepted Answer · edited May 23 '17 at 12:00

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Obsolete attribute is "compiler magic" - you can't do something like this on your own without modifying the compiler. However, as always, there are workarounds - e.g. take a look at this and this thread.

edited May 23 '17 at 12:00

Community

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answered Sep 15 '09 at 08:08

Saulius Valatka

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These are links to answers, not really an answer itself. – Heretic Monkey Jan 08 '23 at 17:24

score 2 · Answer 2 · answered Sep 15 '09 at 08:15

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Any attributes that exhibit this inside the compiler are special cases. The [Obsolete] behaviour is described in the C# spec (17.4.3), for example.

You could write a custom FxCop rule?

answered Sep 15 '09 at 08:15

Marc Gravell

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That doesn't give you the opportunity to give you a compile time error/warning, does it ? – Frederik Gheysels Sep 15 '09 at 08:16
It does if you include FxCop in your build process. In VS2008 (team developer edition) you can do this either by declaring a build symbol, or clicking a checkbox on project properties... – Marc Gravell Sep 15 '09 at 08:20
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For info, it is the CODE_ANALYSIS symbol, or the checkbox on the "Code Analysis" tab. – Marc Gravell Sep 15 '09 at 08:25

How to throw compilation error from an attribute?

2 Answers2

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