gcc vs g++ and linking with as

["Robert J. Brown" <rj@eli.elilabs.com>]

>>>>> "Chris" == Chris Howard <choward@intellistor.com> writes:

    Chris> binutils 2.9 gcc/g++ 2.8.0

    Chris> Host Sun Sparc Solaris 2.5 Target Motorola Coldfire
    Chris> (-m5200) a.out object format

    Chris> ---

    Chris> Not using stdlib (-nostdlib)

    Chris> We have some code in assembler, and some in C.  Compiling
    Chris> with as,gcc and linking with ld works fine.  Compiling with
    Chris> as,g++ and linking with ld does not work, undefined symbols
    Chris> for those things written in assembler.

You will have to declare the asm routines "extern 'C'" because the
assembler does not perform C++ name mangling for you.

    Chris> The .o files output from g++ compilation have exported
    Chris> symbols that end in '__Fv' whereas the assembler output .o
    Chris> files don't have '__Fv' on the symbols.  Is that the
    Chris> problem?  Is there some way to make it work?  What is __Fv?

These  are C++ mangled names.  Use c++filt to de-mangle C++ mangled
names.  The mangling encodes type information into the names so that
the linker can resolve functions with the same name but different
signatures. 

    Chris> An alternative might be to put the assembly code in C/C++
    Chris> wrapper functions.  Any hints/comments that would be
    Chris> appreciated also.

This is not necessary -- just declare the asm functions extern 'C' and 
the compiler will know not to mangle those names, so the linker will
be able to resolve them.

    Chris> -- Chris Howard Fujitsu Computer Products of America
    Chris> Longmont, Colorado

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