[cfe-dev] Is there a way to get linkonce / selectany in C programs?
rnk at google.com
Wed Jul 2 14:13:41 PDT 2014
I can't think of any construct in standard C that will get linkonce_odr
There is __attribute__((weak)) which gives 'weak' linkage. There are two
1. It is not "odr", meaning it can be overridden by a different definition.
Inlining or constant propagation is not allowed.
2. It is not discardable, meaning it cannot be dropped if unreferenced.
On Tue, Jul 1, 2014 at 11:16 PM, Talin <viridia at gmail.com> wrote:
> OK that makes sense. So forget selectany for a moment - what I really want
> to know is, is there any way, from C, to give a symbol linkonce linkage? Or
> is this capability only available via the IR?
> On Tue, Jul 1, 2014 at 11:13 PM, Nikola Smiljanic <popizdeh at gmail.com>
>> Grepping the source code tells me that selectany is only implemented as
>> microsoft extension. Test files use it in combination with __declspec and
>> they enable this functionality with -fsm-compatibility. Note that I have no
>> idea what this attribute actually does, I just did a search for you :)
>> On Wed, Jul 2, 2014 at 2:31 PM, Talin <viridia at gmail.com> wrote:
>>> I'm working with a code generator that produces C code and I need
>>> linkonce to eliminate duplicate definitions - but the clang compiler
>>> complains that the 'selectany' attribute is not recognized (even though I
>>> see looking through the clang source code that there's code to handle it.)
>>> So I'm wondering why the attribute isn't recognized, I'm guessing it could
>>> be any number of things (platform [OS X], source language (.c), and so
>>> -- Talin
>>> cfe-dev mailing list
>>> cfe-dev at cs.uiuc.edu
> -- Talin
> cfe-dev mailing list
> cfe-dev at cs.uiuc.edu
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