[Dev-C++] Newbie linking errors: 'undefined reference'

[Devin C. <dcc...@ya...>]

  Generally, I like to lurk and listen a bit before I post, but this
time I'm really at wit's end.

  My project, a simple game based on the old Lost Worlds
booklets,  keeps generating undefined reference errors in the
linking stage.  They look like this:

d:/devin/projects/lostworlds/womanqsprototype.o(.data$_vt$11WomanQSBook+0x5c
):womanqsprototy: undefined reference to `BaseBook::Lookup(unsigned short,
unsigned short) const'

  The compiler had no problems with just such a function, but
the linker does.  (I'm using Dev-C++ 4 with MinGW 2.95.2,
with the -v -H flags for the linker.)  I don't know what
'undefined reference' means, and nowhere on the Net (that Google
can find) is there a document that tells me, either.
  Sometimes I can temporarily make them go away with cosmetic
changes to the code: moving a function definition from the .cpp to
the .h, moving a function declaration in the .h, etc., seems to work
for individual errors.  But whenever I add a new module they
come back again, twice as plentiful.

  I thought it might be STL and vectors, but changing my
container implementation to use arrays didn't help.  So it's not, as
I thought, STL's fault.  It might be a link order problem, so I
used the Make Makefile function and tried to do things from the
command line.  However, I can't get make to work with the
Dev-C++'s makefiles: it gives me errors like '**18: Multiple
targets.'  And Dev-C++'s Project Options only asks for
-additional- arguments to pass to the linker.
  So I'm really getting demoralized.  This problem has held me
up for three days now.  I'd very much appreciate some assistance.

  It has been suggested I provide a code fragment, but since the
errors seem to be independent of legality of the code, and only
crop up when the projects gets big, I don't see how it would help.
However, I will provide such a thing if asked, though I really have
no idea what could be relevant to the problem.

--Devin Carless




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