Red Hat ENTERPRISE LINUX 4 Manual page 14

6
GCC aims towards being usable as a conforming freestanding implementation, or as the compiler for
a conforming hosted implementation. By default, it will act as the compiler for a hosted implemen-
tation, defining
__STDC_HOSTED__
used, they have the semantics defined in the standard. To make it act as a conforming freestanding
implementation for a freestanding environment, use the option
__STDC_HOSTED__
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. Section 4.4 Options Controlling C Dialect.
GCC does not provide the library facilities required only of hosted implementations, nor yet all the fa-
cilities required by C99 of freestanding implementations; to use the facilities of a hosted environment,
you will need to find them elsewhere (for example, in the GNU C library). Section 11.7 Standard
Libraries.
Most of the compiler support routines used by GCC are present in
tions. GCC requires the freestanding environment provide
Some older ports of GCC are configured to use the BSD
but this is deprecated for new ports. Finally, if
implement the
trap
For references to Technical Corrigenda, Rationale documents and information concerning the history
of C that is available online, see http://gcc.gnu.org/readings.html
There is no formal written standard for Objective-C. The most authoritative manual is
"Object-Oriented Programming and the Objective-C Language", available at a number of web sites
http://developer.apple.com/techpubs/macosx/Cocoa/ObjectiveC/ is a recent version
•
http://www.toodarkpark.org/computers/objc/ is an older example
•
http://www.gnustep.org has additional useful information
•
There is no standard for treelang, which is a sample language front end for GCC. Its only purpose
is as a sample for people wishing to write a new language for GCC. The language is documented in
gcc/treelang/treelang.texi
as and presuming that when the names of ISO C functions are
1
to and not make assumptions about the meanings of function names from the
0
pattern, then GCC will emit a call to
which can be turned into info or HTML format.
Chapter 3. Language Standards Supported by GCC
-ffreestanding
libgcc
memcpy
,
bcopy bzero
__builtin_trap
.
abort
; it will then define
, but there are a few excep-
, ,
memmove memset
and functions instead,
bcmp
is used, and the target does not
and .
memcmp