[Clp] undefined symbols when opening library via dlopen - proposed fix

[Carlo Baldassi]

Hi,

I have been experiencing the same problem mentioned in this thread:

http://list.coin-or.org/pipermail/coin-discuss/2008-October/003480.html

i.e. calling dlopen("libClp") I get "undefined symbols" errors:

$ ldd -d libClp.so
	linux-vdso.so.1 =>  (0x00007fff34fff000)
	libstdc++.so.6 => /usr/lib/x86_64-linux-gnu/libstdc++.so.6 (0x00007f3eadcfd000)
	libm.so.6 => /lib/x86_64-linux-gnu/libm.so.6 (0x00007f3eada03000)
	libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x00007f3ead645000)
	libgcc_s.so.1 => /lib/x86_64-linux-gnu/libgcc_s.so.1 (0x00007f3ead42f000)
	/lib64/ld-linux-x86-64.so.2 (0x00007f3eae3a2000)
undefined symbol: _ZTI18CoinMessageHandler	(./libClp.so)
undefined symbol: _ZN18CoinMessageHandler13checkSeverityEv	(./libClp.so)
undefined symbol: _ZTI20CoinOslFactorization	(./libClp.so)
undefined symbol: _ZN9CoinError12printErrors_E	(./libClp.so)
undefined symbol: _ZTI21CoinSimpFactorization	(./libClp.so)
undefined symbol: _ZTI13CoinBaseModel	(./libClp.so)
undefined symbol: _ZTI19CoinStructuredModel	(./libClp.so)
undefined symbol: _ZTI9CoinModel	(./libClp.so)
undefined symbol: _ZTI22CoinOtherFactorization	(./libClp.so)
undefined symbol: _ZTI22CoinDenseFactorization	(./libClp.so)

The missing symbols are defined in libCoinUtils.so, but I cannot load
it beforehand.

Also, this prevents the following to work:

./configure LDFLAGS="-Wl,--no-undefined"