core.stdc.stdio - change stdout, etc., to enum for -betterC

[WalterBright]

Having stdout, etc., be a variable means druntime needs to be linked in, meaning they do not work for -betterC. Switching to an enum makes it work.

[dlang-bot]

Thanks for your pull request, @WalterBright!

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[dnadlinger]

Doesn't this break &stdin (and compatibility with other runtimes)?

[WalterBright]

Doesn't this break &stdin

Given the vagaries of how stdin is implemented in various C implementations (none of them are the same), and code relying on C stdin being an lvalue is not going to be portable anyway. Sometimes the implementations are a function, not a variable, where taking the address won't give what you presumably want.

(and compatibility with other runtimes)?

This one is specific to the Digital Mars C runtime.

Note that this change is necessary to make betterC code able to access stdin at all. In general, core.stdc implementations should try to find ways that do not require linking in druntime.

[schveiguy]

I agree with Walter on this, the vagaries of how any C implementation defines the standard FILE * handles should be forwarded without any extra machinery. Portable code shouldn't make any assumptions about how it works, or depend on a druntime abstraction.

[schveiguy]

ping @CyberShadow any ideas on the doc build failure? They look internal to the build system itself, but I'm not 100% sure.

[wilzbach]

They look internal to the build system itself, but I'm not 100% sure.

I think this has been fixed one or two days ago. Unfortunately the only way to rekick DAutoTest is to rebase (unfortunately I can't help here as I'm without a computer atm).

[CyberShadow]

@schveiguy It's green now so I'm not sure what the error was, but judging from other build failures in the past few days, it was almost certainly due to code.dlang.org being down.

[schveiguy]

I'm not sure what the error was

This was the failed build: http://dtest.dlang.io/results/209be21a8f62782bb5b8f66edc7f9f8d62e1c439/2b5450cb012263aa23aad9c24f9528adefbba887/