Linking in debugging mode is fine: $ make CNF=gcc MODE=debug scons -j 2 CNF=gcc MODE=debug BACKEND= scons: Reading SConscript files ... scons: done reading SConscript files. scons: Building targets ... g++ -o main.o -c -pipe -I. -Wall -g -fopenmp main.cpp g++ -o tinystr.o -c -pipe -I. -Wall -g -fopenmp tinystr.cpp g++ -o tinyxml.o -c -pipe -I. -Wall -g -fopenmp tinyxml.cpp g++ -o tinyxmlerror.o -c -pipe -I. -Wall -g -fopenmp tinyxmlerror.cpp g++ -o tinyxmlparser.o -c -pipe -I. -Wall -g -fopenmp tinyxmlparser.cpp g++ -o shapes -g -fopenmp tinystr.o tinyxml.o tinyxmlerror.o tinyxmlparser.o main.o -lcvmlcpp scons: done building targets.
But in release mode, it's not: $ make CNF=gcc scons -j 2 CNF=gcc MODE= BACKEND= scons: Reading SConscript files ... scons: done reading SConscript files. scons: Building targets ... g++ -o main.o -c -pipe -I. -Wall -O3 -funroll-loops -fopenmp -march=native -ftree-vectorize -DNDEBUG main.cpp g++ -o tinystr.o -c -pipe -I. -Wall -O3 -funroll-loops -fopenmp -march=native -ftree-vectorize -DNDEBUG tinystr.cpp g++ -o tinyxml.o -c -pipe -I. -Wall -O3 -funroll-loops -fopenmp -march=native -ftree-vectorize -DNDEBUG tinyxml.cpp g++ -o tinyxmlerror.o -c -pipe -I. -Wall -O3 -funroll-loops -fopenmp -march=native -ftree-vectorize -DNDEBUG tinyxmlerror.cpp g++ -o tinyxmlparser.o -c -pipe -I. -Wall -O3 -funroll-loops -fopenmp -march=native -ftree-vectorize -DNDEBUG tinyxmlparser.cpp g++ -o shapes -fopenmp tinystr.o tinyxml.o tinyxmlerror.o tinyxmlparser.o main.o -lcvmlcpp main.o: In function `_ZN7cvmlcppL25extractSurfaceFromAdapterIN6shapes20ShapeSurfaceAdaptor_IdEEdEEvRKT_RNS_8GeometryIT0_EEd.omp_fn.1': main.cpp:(.text+0x5838): undefined reference to `void cvmlcpp::extractSurfaceFromAdapter<shapes::ShapeSurfaceAdaptor_<double>, double>(shapes::ShapeSurfaceAdaptor_<double> const&, cvmlcpp::Geometry<double>&, double)::C.724' collect2: ld returned 1 exit status scons: *** [shapes] Error 1 scons: building terminated because of errors. make: *** [compile] Error 2 $ g++ -v Using built-in specs. Target: x86_64-linux-gnu Configured with: ../src/configure -v --with-pkgversion='Ubuntu 4.3.2-1ubuntu12' --with-bugurl=file:///usr/share/doc/gcc-4.3/README.Bugs --enable-languages=c,c++,fortran,objc,obj-c++ --prefix=/usr --enable-shared --with-system-zlib --libexecdir=/usr/lib --without-included-gettext --enable-threads=posix --enable-nls --with-gxx-include-dir=/usr/include/c++/4.3 --program-suffix=-4.3 --enable-clocale=gnu --enable-libstdcxx-debug --enable-objc-gc --enable-mpfr --enable-checking=release --build=x86_64-linux-gnu --host=x86_64-linux-gnu --target=x86_64-linux-gnu Thread model: posix gcc version 4.3.2 (Ubuntu 4.3.2-1ubuntu12) Unfortunately, I'm not exactly sure how to complete this report. I have no idea what component does this, so I just guessed. And should I simply attach all source code ? -- Summary: linking fails when optimizations are enabled Product: gcc Version: 4.3.2 Status: UNCONFIRMED Severity: normal Priority: P3 Component: other AssignedTo: unassigned at gcc dot gnu dot org ReportedBy: fpbeekhof at gmail dot com http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39573