Add Obsolete warnings to all System.Data.SqlClient public APIs

[cheenamalhotra]

Addresses #125

Updated:

• Only Public APIs are marked Obsolete, warning CS0618 disabled across projects.
• PNSE assemblies are also updated with Obsolete attributes.

[carlossanlop]

While working on public APIs, the usage of those in internal classes also incurred CS0618 warnings for which I marked "SqlClient specific" internal APIs are obsolete too. Let me know for any concerns.

Isn't all System.Data.SqlClient supposed to be marked as obsolete? I was unable to understand the pattern of adding the Obsolete attribute to some specific APIs but not others. Why not add it at the assembly level?

Since we don't have .NET Standard functional asset, skipping check for that, would appreciate any feedback.

Can you please elaborate on that?

maintenance-packages/src/System.Data.SqlClient/src/System.Data.SqlClient.csproj

Line 4 in d85f3c5

<TargetFrameworks>$(NetCurrent)-windows;$(NetCurrent)-unix;$(NetCurrent);$(NetMinimum)-windows;$(NetMinimum)-unix;$(NetMinimum);netstandard2.0;$(NetFrameworkMinimum)</TargetFrameworks>

[cheenamalhotra]

I looked up ObsoleteAttribute documentation and couldn't find any other way to mark APIS obsolete. Based on remarks I don't see they support at Assembly level.

Let me know if you have a way to may it work.

Regarding .Net Standard 2.0 target, yes we target the same but it's a PNSE assembly in the new package which doesn't compile these classes but the notsupported.cs file. I wasn't sure if we need to add the Obsolete attributes there.

[ViktorHofer]

Yes, the .notsupported.cs file needs the Obsolete attributes as well. As Carlos mentioned, internal API doesn't need to be annotated with the attribute.

I looked up ObsoleteAttribute documentation and couldn't find any other way to mark APIS obsolete. Based on remarks I don't see they support at Assembly level.

Correct, the ObsoleteAttribute can't be put on assemblies or modules.

[carlossanlop]

Correct, the ObsoleteAttribute can't be put on assemblies or modules.

Can't it be placed on top of a namespace?

Edit: I checked, apparently it cannot be done. Oh well.

[carlossanlop]

LGTM. I see now all public APIs have the attribute.
Thanks for removing the xmls.
It's a bummer that we can't localize the obsolete string.
Let's wait for any comments from @ViktorHofer , if any.