mirror/gcc
2
0
Fork 0
mirror of git://gcc.gnu.org/git/gcc.git synced 2025-03-09 17:47:25 +08:00
Code Issues Packages Projects Releases Wiki Activity

* doc/standards.texi: Document required freestanding libc entry points.

Browse Source 
From-SVN: r51768
This commit is contained in:
Richard Henderson 2002-04-02 16:12:59 -08:00 committed by Richard Henderson
parent c94ccb87d7
commit 3a07982299
2 changed files with 18 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
gcc/ChangeLog
View File

@ -1,3 +1,7 @@
2002-04-02 Richard Henderson <rth@redhat.com>
* doc/standards.texi: Document required freestanding libc entry points.
2002-04-02 Alan Modra <amodra@bigpond.net.au>
* config/rs6000/rs6000.md (ctrdi*): Add FPR constraint and

18
gcc/doc/standards.texi
View File

@ -132,10 +132,10 @@ the semantics defined in the standard. To make it act as a conforming
freestanding implementation for a freestanding environment, use the
option @option{-ffreestanding}; it will then define
@code{__STDC_HOSTED__} to @code{0} and not make assumptions about the
meanings of function names from the standard library. To build an OS
kernel, you may well still need to make your own arrangements for
linking and startup. @xref{C Dialect Options,,Options Controlling C
Dialect}.
meanings of function names from the standard library, with exceptions
noted below. To build an OS kernel, you may well still need to make
your own arrangements for linking and startup.
@xref{C Dialect Options,,Options Controlling C Dialect}.
GCC does not provide the library facilities required only of hosted
implementations, nor yet all the facilities required by C99 of
@ -143,6 +143,16 @@ freestanding implementations; to use the facilities of a hosted
environment, you will need to find them elsewhere (for example, in the
GNU C library). @xref{Standard Libraries,,Standard Libraries}.
Most of the compiler support routines used by GCC are present in
@file{libgcc}, but there are a few exceptions. GCC requires the
freestanding environment provide @code{memcpy}, @code{memmove},
@code{memset} and @code{memcmp}. Some older ports of GCC are
configured to use the BSD @code{bcopy}, @code{bzero} and @code{bcmp}
functions instead, but this is deprecated for new ports.
Finally, if @code{__builtin_trap} is used, and the target does
not implement the @code{trap} pattern, then GCC will emit a call
to @code{abort}.
For references to Technical Corrigenda, Rationale documents and
information concerning the history of C that is available online, see
@uref{http://gcc.gnu.org/readings.html}