std library hooks

[Nick Sabalausky]

"Walter Bright" <newshound2 at digitalmars.com> wrote in message 
news:jmg9r2$1s3u$1 at digitalmars.com...
> On 4/15/2012 9:49 PM, Nick Sabalausky wrote:
>> The link-time "hook" system has such horrid
>> semantics, diagnostics and compatibility, you're gonne need to document 
>> the
>> hell out of that if you expect people to actually use it.
>
> What's so hard about:
>
> "If you want to override the standard library function _d_assertm(), 
> provide your own somewhere in your source code, like this:"
>
> extern (C) void __dassertm(ModuleInfo* m, uint linenum)
> {
>    ....
>    printf("I failed\n");
>    exit(EXIT_FAILURE);
> }
>
> ??

Aside from the cmdline order subtleties, this is what's bugging me:

2012/4/15 "Jérôme M. Berger" <jeberger at free.fr>
>         In addition to what you have just said, there is another 
> subtility.
> If either main.o or aux.o references another symbol mylibfunc2, and
> if both mylibfunc and mylibfunc2 are provided by the *same* object
> file inside mylib.a, then when the linker pulls in mylibfunc2 it
> will *also* pull in mylibfunc and complain about a duplicate
> definition. This also depends on your version of the compiler and
> linker, and on the compilation options (I believe the
> -ffunction-sections gcc option makes the issue disappear for example).