This is the mail archive of the
ecos-devel@sourceware.org
mailing list for the eCos project.
Strange __cxa_pure_virtual problem
- From: Uwe Kindler <uwe_kindler at web dot de>
- To: ecos-devel at sourceware dot org
- Date: Wed, 05 Aug 2009 20:55:07 +0200
- Subject: Strange __cxa_pure_virtual problem
Hi,
I'm currently in the process of testing uSTL library port. I tried to
build the library without filestream support and without package file I/O.
The library build process succeeds. Bu if I start building the test
cases then the compiler fails on building diag_sprintf1 test with the
error message:
make[1]: Leaving directory
`/home/Nutzer/ustl_test_08_nofio_build/infra/current'
/opt/ecos/gnutools/arm-eabi/bin/../lib/gcc/arm-eabi/4.3.2/../../../../arm-eabi/lib/nointerwork/libsupc++.a(pure.o):
In function `__cxa_pure_virtual':
make: Leaving directory `/home/Nutzer/ustl_test_08_nofio_build'
(.text.__cxa_pure_virtual+0x14): undefined reference to `write'
collect2: ld returned 1 exit status
So the compiler/linker does not link the __cxa_pure_virtual function in
infra/current/src/pure.cxx and instead takes the implementation from
libsupc++.
In the libsupc++ source file pure.cc the function __cxa_pure_virtual
writes an error string to stderr via 'write' function. Because no file
I/O package is present, there is no write function and the reference to
'write' is undefinded.
This error only occures for debug builds (-g2 -O0). If I build with -g
-O2 this error does not occur. This problem does not occur, if I link my
main.cpp application against the library but it occures when I build
test cases. As soon as I add the file I/O package, the tests build
process succeeds because a 'write' function is present.
The question is, how can/should I solve this problem? Is there a way to
force the compiler/linker to use the infra/current/src/pure.cxx
implementation or should I provide a dummy 'write' function in uSTL
package if file I/O package is not present?
Regards, Uwe