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Re: Documenting tools necessary for GCC [draft]
- From: dewar at gnat dot com (Robert Dewar)
- To: fjh at cs dot mu dot OZ dot AU, zack at codesourcery dot com
- Cc: gcc at gcc dot gnu dot org, obrien at freebsd dot org
- Date: Sun, 1 Jun 2003 08:42:05 -0400 (EDT)
- Subject: Re: Documenting tools necessary for GCC [draft]
> The C standard gives an implementor far less wiggle room.
Basically the C standard was written to enable the writing of portable
code, and required C compilers to conform to a common functional spec
for a large part of the language.
The Posix spec is not written with this in mind, there are huge and
significant unspecified functionalities (for example, POSIX threads
does not even bother to precisely define the dispatching model).
As Zack says, the point of the POSIX spec was to create a common
set of functionalities. If you have a POSIX compliant technology,
then the idea is that you are guaranteed that you have an appropriate
basic set of functions, but you are definitely not guaranteed that
your posix code from another system will port unchanged.
Yes, you can carefully write to the common guaranteed subset, but this
is not particularly the intention of the standard, and is in practice
very difficult to do.