On Wed, 23 Jan 2008, Michael Witten wrote:
These cross-compilers don't need access to any kind of
libraries or headers.
They don't need C libraries, or libstdc++, or libobjc,
or anything that has absolutely nothing to do whatsoever
with compilation.
Can I build gcc in this way?
Build gcc with the libc that goes into the target.
Compile your code with one or more of.....
`-nostartfiles'
Do not use the standard system startup files when linking. The
standard system libraries are used normally, unless `-nostdlib' or
`-nodefaultlibs' is used.
`-nodefaultlibs'
Do not use the standard system libraries when linking. Only the
libraries you specify will be passed to the linker. The standard
startup files are used normally, unless `-nostartfiles' is used.
The compiler may generate calls to `memcmp', `memset', `memcpy'
and `memmove'. These entries are usually resolved by entries in
libc. These entry points should be supplied through some other
mechanism when this option is specified.
`-nostdlib'
Do not use the standard system startup files or libraries when
linking. No startup files and only the libraries you specify will
be passed to the linker. The compiler may generate calls to
`memcmp', `memset', `memcpy' and `memmove'. These entries are
usually resolved by entries in libc. These entry points should be
supplied through some other mechanism when this option is
specified.
One of the standard libraries bypassed by `-nostdlib' and
`-nodefaultlibs' is `libgcc.a', a library of internal subroutines
that GCC uses to overcome shortcomings of particular machines, or
special needs for some languages. (*Note Interfacing to GCC
Output: (gccint)Interface, for more discussion of `libgcc.a'.) In
most cases, you need `libgcc.a' even when you want to avoid other
standard libraries. In other words, when you specify `-nostdlib'
or `-nodefaultlibs' you should usually specify `-lgcc' as well.
This ensures that you have no unresolved references to internal GCC
library subroutines. (For example, `__main', used to ensure C++
constructors will be called; *note `collect2': (gccint)Collect2.)
John Carter Phone : (64)(3) 358 6639
Tait Electronics Fax : (64)(3) 359 4632
PO Box 1645 Christchurch Email : john.carter@xxxxxxxxxx
New Zealand
