Re: Problems compiling xsystem35 under cygwin

[Igor Pechtchanski <pechtcha at cs dot nyu dot edu>]

On Thu, 31 Jul 2003, Thomas Morgan wrote:

> > Or, you could use the precompiled binaries distributed by the KDE on
> > Cygwin project that already have SHM enabled.
>
> Well, that solved about half the problem.
>
> Now it does this...
>
> gcc: unrecognized option `-rdynamic'
> xsystem35.o(.text+0x1700):xsystem35.c: undefined reference to `_haveUNIT'
> image.o(.text+0x1b5d):image.c: undefined reference to `_ablend16_ppp'
> image.o(.text+0x198c):image.c: undefined reference to `_ablend16_dpd'
> image.o(.text+0x1d64):image.c: undefined reference to `_ablend16_ppd'
> image.o(.text+0x1e81):image.c: undefined reference to `_ablend16_ppd'
> collect2: ld returned 1 exit status
> BASH-2.05b$
>
> The ablend16 ones are from alpha_blend16.o, which is made from assembly
> language source. Since it's linked in before image.o is, I don't know
> why it couldn't find it. (Admittedly, I have little experience with
> linking large multiple-file programs.)  haveUNIT also seems to come from
> an assembly language file, so maybe that's part of the problem.

Actually, you've got it backwards.  The linker normally looks for
unresolved references in *later* files, so you should place the file
providing the function on the command line *after* the one using the
function.  However, this may only pertain to libraries.  Check the
function names in assembly code -- you might need to explicitly prepend
the underscore to these names, as that's how C looks for them.
Alternatively, you may need to pass some options to the assembler to do
the name mangling for you.
	Igor
-- 
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