Re: [Bug-gnulib] xmalloc and rpl_malloc

[Bruno Haible]

Paul Eggert writes:

> It's not to fulfill the C Standard.  The C Standard prohibits a
> program from defining any external symbol that is defined by the
> standard libraries.  This holds even if the program doesn't include
> the corresponding header.
> 
> POSIX-only symbols are different.  A POSIX program is free to define an
> external symbol 'open' so long as it doesn't include any header that
> declares 'open'.
> 
> Those ELF mechanisms are needed to handle the case of POSIX-only
> symbols.

Thanks for explaining. But it is confusing that you say

PE> A POSIX program is free to define an external symbol 'open' so long
PE> as it doesn't include any header that declares 'open'.

whereas Roland McGrath in
http://sources.redhat.com/ml/libc-alpha/2002-08/msg00278.html
essentially said:

    A POSIX program is free to define an external symbol 'open' so long
    as it doesn't use any POSIX function not defined also in ISO C.

Bruno