<html><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class=""><div class=""><br class=""></div> I found<div class=""><br class=""></div><div class=""><a href="http://icl.cs.utk.edu/lapack-forum/viewtopic.php?f=2&t=1730" class="">http://icl.cs.utk.edu/lapack-forum/viewtopic.php?f=2&t=1730</a></div><div class=""><br class=""></div><div class="">but I do not understand it.</div><div class=""><br class=""><div>I am pretty sure PETSc is not providing in anyway even through its packages like fblaslapack <i class="" style="font-family: Calibri, sans-serif; font-size: 11pt;">blas_sgemv_x </i>anyway I would focus on figuring out where those are coming from. Normal compilers won't need them. Do you use them? </div><div><br class=""></div><div> Good luck</div><div><br class=""></div><div> Barry</div><div><br class=""><blockquote type="cite" class=""><div class="">On Oct 23, 2020, at 7:21 PM, Thuc Bui <<a href="mailto:bui@calcreek.com" class="">bui@calcreek.com</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><div class="WordSection1" style="page: WordSection1; caret-color: rgb(0, 0, 0); font-family: Helvetica; font-size: 18px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;"><div style="margin: 0in 0in 0.0001pt; font-size: 11pt; font-family: Calibri, sans-serif;" class=""><span style="font-family: "Times New Roman", serif;" class="">Dear Petsc Users,<span class="Apple-converted-space"> </span><o:p class=""></o:p></span></div><div style="margin: 0in 0in 0.0001pt; font-size: 11pt; font-family: Calibri, sans-serif;" class=""><span style="font-family: "Times New Roman", serif;" class=""><o:p class=""> </o:p></span></div><div style="margin: 0in 0in 0.0001pt; font-size: 11pt; font-family: Calibri, sans-serif;" class=""><span style="font-family: "Times New Roman", serif;" class="">I hope someone out there has already encountered the same linking problem and already figured this out, or has some idea how to resolve this issue. I have google searched but haven’t found any solution.<o:p class=""></o:p></span></div><div style="margin: 0in 0in 0.0001pt; font-size: 11pt; font-family: Calibri, sans-serif;" class=""><span style="font-family: "Times New Roman", serif;" class=""><o:p class=""> </o:p></span></div><div style="margin: 0in 0in 0.0001pt; font-size: 11pt; font-family: Calibri, sans-serif;" class=""><span style="font-family: "Times New Roman", serif;" class="">I successfully ported Petsc 3.13.5 both as shared and static libraries in both Windows 10 (Visual Studio 2015, no Fortran) and Ubuntu 20.4 (gcc, g++. gfortran 9.3), and successfully run “make check” in all. I am also able to build my own shared libraries linked to either shared or static Petsc library in both platforms. I was also able to link and execute my application to either of these shared libraries in Windows. Unfortunately, I could only get my app to link and execute with the shared library linked to the shared Petsc library in Ubuntu, but not with the static Petsc library.<o:p class=""></o:p></span></div><div style="margin: 0in 0in 0.0001pt; font-size: 11pt; font-family: Calibri, sans-serif;" class=""><span style="font-family: "Times New Roman", serif;" class=""><o:p class=""> </o:p></span></div><div style="margin: 0in 0in 0.0001pt; font-size: 11pt; font-family: Calibri, sans-serif;" class=""><span style="font-family: "Times New Roman", serif;" class="">On Ubuntu, below is how I build Petsc static library, which produces three libraries: libpetsc.a, libfblas.a and libflapack.a<o:p class=""></o:p></span></div><div style="margin: 0in 0in 0.0001pt; font-size: 11pt; font-family: Calibri, sans-serif;" class=""><i class=""><o:p class=""> </o:p></i></div><div style="margin: 0in 0in 0.0001pt; font-size: 11pt; font-family: Calibri, sans-serif;" class=""><i class="">./configure CFLAGS="-fPIC" CXXFLAGS="-fPIC" FFLAGS="-fPIC" -with-cc=gcc --with-cxx=g++ --with-fc=gfortran --with-openmp --with-debugging=0 --download-fblaslapack --with-mpi=0 --with-shared-libraries=0<o:p class=""></o:p></i></div><div style="margin: 0in 0in 0.0001pt; font-size: 11pt; font-family: Calibri, sans-serif;" class=""><span style="font-family: "Times New Roman", serif;" class=""><o:p class=""> </o:p></span></div><div style="margin: 0in 0in 0.0001pt; font-size: 11pt; font-family: Calibri, sans-serif;" class=""><span style="font-family: "Times New Roman", serif;" class="">Below is the make output on how I build my shared library, cPoissons.so linking to the static Petsc. Please note that I have to use --allow-multiple-definition to override the redefinition errors in lapack and blas. I also use --whole-archive to make sure the shared library has all the required information from lapack and blas.<o:p class=""></o:p></span></div><div style="margin: 0in 0in 0.0001pt; font-size: 11pt; font-family: Calibri, sans-serif;" class=""><b class=""><span style="font-family: "Times New Roman", serif;" class=""><o:p class=""> </o:p></span></b></div><div style="margin: 0in 0in 0.0001pt; font-size: 11pt; font-family: Calibri, sans-serif;" class=""><i class="">gcc -fPIC -c -o gcc/matrixUtil.o matrixUtil.c<span class="Apple-converted-space"> </span><o:p class=""></o:p></i></div><div style="margin: 0in 0in 0.0001pt; font-size: 11pt; font-family: Calibri, sans-serif;" class=""><i class=""> -I/home/bbwannabe/Documents/Petsc/latest/include<span class="Apple-converted-space"> </span><o:p class=""></o:p></i></div><div style="margin: 0in 0in 0.0001pt; font-size: 11pt; font-family: Calibri, sans-serif;" class=""><i class=""> -I/home/bbwannabe/Documents/Petsc/latest/include/petsc/private<span class="Apple-converted-space"> </span><o:p class=""></o:p></i></div><div style="margin: 0in 0in 0.0001pt; font-size: 11pt; font-family: Calibri, sans-serif;" class=""><i class=""> -I/home/bbwannabe/Documents/Petsc/latest/gcc-x64SRelease/include <span class="Apple-converted-space"> </span><o:p class=""></o:p></i></div><div style="margin: 0in 0in 0.0001pt; font-size: 11pt; font-family: Calibri, sans-serif;" class=""><i class="">gcc -fPIC -c -o gcc/PetscSolver.o PetscSolver.c<span class="Apple-converted-space"> </span><o:p class=""></o:p></i></div><div style="margin: 0in 0in 0.0001pt; font-size: 11pt; font-family: Calibri, sans-serif;" class=""><i class=""> -I/home/bbwannabe/Documents/Petsc/latest/include<span class="Apple-converted-space"> </span><o:p class=""></o:p></i></div><div style="margin: 0in 0in 0.0001pt; font-size: 11pt; font-family: Calibri, sans-serif;" class=""><i class=""> -I/home/bbwannabe/Documents/Petsc/latest/include/petsc/private<span class="Apple-converted-space"> </span><o:p class=""></o:p></i></div><div style="margin: 0in 0in 0.0001pt; font-size: 11pt; font-family: Calibri, sans-serif;" class=""><i class=""> -I/home/bbwannabe/Documents/Petsc/latest/gcc-x64SRelease/include<o:p class=""></o:p></i></div><div style="margin: 0in 0in 0.0001pt; font-size: 11pt; font-family: Calibri, sans-serif;" class=""><i class="">gcc -fPIC -c -o gcc/LinearSystemSolver.o LinearSystemSolver.c<span class="Apple-converted-space"> </span><o:p class=""></o:p></i></div><div style="margin: 0in 0in 0.0001pt; font-size: 11pt; font-family: Calibri, sans-serif;" class=""><i class=""> -I/home/bbwannabe/Documents/Petsc/latest/include<span class="Apple-converted-space"> </span><o:p class=""></o:p></i></div><div style="margin: 0in 0in 0.0001pt; font-size: 11pt; font-family: Calibri, sans-serif;" class=""><i class=""> -I/home/bbwannabe/Documents/Petsc/latest/include/petsc/private<span class="Apple-converted-space"> </span><o:p class=""></o:p></i></div><div style="margin: 0in 0in 0.0001pt; font-size: 11pt; font-family: Calibri, sans-serif;" class=""><i class=""> -I/home/bbwannabe/Documents/Petsc/latest/gcc-x64SRelease/include<o:p class=""></o:p></i></div><div style="margin: 0in 0in 0.0001pt; font-size: 11pt; font-family: Calibri, sans-serif;" class=""><i class="">gcc -fPIC -c -o gcc/cPoisson.o cPoisson.c<span class="Apple-converted-space"> </span><o:p class=""></o:p></i></div><div style="margin: 0in 0in 0.0001pt; font-size: 11pt; font-family: Calibri, sans-serif;" class=""><i class=""> -I/home/bbwannabe/Documents/Petsc/latest/include<span class="Apple-converted-space"> </span><o:p class=""></o:p></i></div><div style="margin: 0in 0in 0.0001pt; font-size: 11pt; font-family: Calibri, sans-serif;" class=""><i class=""> -I/home/bbwannabe/Documents/Petsc/latest/include/petsc/private<span class="Apple-converted-space"> </span><o:p class=""></o:p></i></div><div style="margin: 0in 0in 0.0001pt; font-size: 11pt; font-family: Calibri, sans-serif;" class=""><i class=""> -I/home/bbwannabe/Documents/Petsc/latest/gcc-x64SRelease/include<o:p class=""></o:p></i></div><div style="margin: 0in 0in 0.0001pt; font-size: 11pt; font-family: Calibri, sans-serif;" class=""><i class="">gcc -fPIC -fopenmp -shared -o gcc/cPoissons.so gcc/matrixUtil.o gcc/PetscSolver.o gcc/LinearSystemSolver.o gcc/cPoisson.o<span class="Apple-converted-space"> </span><o:p class=""></o:p></i></div><div style="margin: 0in 0in 0.0001pt; font-size: 11pt; font-family: Calibri, sans-serif;" class=""><i class=""> -L/home/bbwannabe/Documents/Petsc/latest/gcc-x64SRelease/lib<span class="Apple-converted-space"> </span><o:p class=""></o:p></i></div><div style="margin: 0in 0in 0.0001pt; font-size: 11pt; font-family: Calibri, sans-serif;" class=""><i class=""> -Wl,--allow-multiple-definition<span class="Apple-converted-space"> </span><o:p class=""></o:p></i></div><div style="margin: 0in 0in 0.0001pt; font-size: 11pt; font-family: Calibri, sans-serif;" class=""><i class=""> -Wl,--whole-archive -lpetsc -lflapack -lfblas -Wl,--no-whole-archive<o:p class=""></o:p></i></div><div style="margin: 0in 0in 0.0001pt; font-size: 11pt; font-family: Calibri, sans-serif;" class=""><i class=""><o:p class=""> </o:p></i></div><div style="margin: 0in 0in 0.0001pt; font-size: 11pt; font-family: Calibri, sans-serif;" class=""><span style="font-family: "Times New Roman", serif;" class="">However, when I build my app linking to the above shared library cPoissons.so. gfortran complains about undefined references, which seem to be from blas as shown below from the output of make. Has anyone seen this kind of linking problem before?<span class="Apple-converted-space"> </span><o:p class=""></o:p></span></div><div style="margin: 0in 0in 0.0001pt; font-size: 11pt; font-family: Calibri, sans-serif;" class=""><span style="font-family: "Times New Roman", serif;" class=""><o:p class=""> </o:p></span></div><div style="margin: 0in 0in 0.0001pt; font-size: 11pt; font-family: Calibri, sans-serif;" class=""><span style="font-family: "Times New Roman", serif;" class="">Many thanks for your help.<o:p class=""></o:p></span></div><div style="margin: 0in 0in 0.0001pt; font-size: 11pt; font-family: Calibri, sans-serif;" class="">Thuc Bui<o:p class=""></o:p></div><div style="margin: 0in 0in 0.0001pt; font-size: 11pt; font-family: Calibri, sans-serif;" class="">Senior R&D Engineer<o:p class=""></o:p></div><div style="margin: 0in 0in 0.0001pt; font-size: 11pt; font-family: Calibri, sans-serif;" class="">Calabazas Creek Research, Inc.<o:p class=""></o:p></div><div style="margin: 0in 0in 0.0001pt; font-size: 11pt; font-family: Calibri, sans-serif;" class="">(650) 948-5361 (Office)<o:p class=""></o:p></div><div style="margin: 0in 0in 0.0001pt; font-size: 11pt; font-family: Calibri, sans-serif;" class=""><span style="font-family: "Times New Roman", serif;" class=""><o:p class=""> </o:p></span></div><div style="margin: 0in 0in 0.0001pt; font-size: 11pt; font-family: Calibri, sans-serif;" class=""><i class="">gfortran -fPIC -o sPoisson3D Poisson3D.f -L/home/bbwannabe/Documents/Nemesis/cPoisson/gcc -l:cPoissons.so<span class="Apple-converted-space"> </span><o:p class=""></o:p></i></div><div style="margin: 0in 0in 0.0001pt; font-size: 11pt; font-family: Calibri, sans-serif;" class=""><i class="">/usr/bin/ld: /home/bbwannabe/Documents/Nemesis/cPoisson/gcc/cPoissons.so: undefined reference to `blas_sgemv_x_'<o:p class=""></o:p></i></div><div style="margin: 0in 0in 0.0001pt; font-size: 11pt; font-family: Calibri, sans-serif;" class=""><i class="">/usr/bin/ld: /home/bbwannabe/Documents/Nemesis/cPoisson/gcc/cPoissons.so: undefined reference to `blas_zgemv_x_'<o:p class=""></o:p></i></div><div style="margin: 0in 0in 0.0001pt; font-size: 11pt; font-family: Calibri, sans-serif;" class=""><i class="">/usr/bin/ld: /home/bbwannabe/Documents/Nemesis/cPoisson/gcc/cPoissons.so: undefined reference to `blas_cgbmv_x_'<o:p class=""></o:p></i></div><div style="margin: 0in 0in 0.0001pt; font-size: 11pt; font-family: Calibri, sans-serif;" class=""><i class="">/usr/bin/ld: /home/bbwannabe/Documents/Nemesis/cPoisson/gcc/cPoissons.so: undefined reference to `blas_cgbmv2_x_'<o:p class=""></o:p></i></div><div style="margin: 0in 0in 0.0001pt; font-size: 11pt; font-family: Calibri, sans-serif;" class=""><i class="">/usr/bin/ld: /home/bbwannabe/Documents/Nemesis/cPoisson/gcc/cPoissons.so: undefined reference to `blas_chemv2_x_'<o:p class=""></o:p></i></div><div style="margin: 0in 0in 0.0001pt; font-size: 11pt; font-family: Calibri, sans-serif;" class=""><i class="">/usr/bin/ld: /home/bbwannabe/Documents/Nemesis/cPoisson/gcc/cPoissons.so: undefined reference to `blas_csymv2_x_'<o:p class=""></o:p></i></div><div style="margin: 0in 0in 0.0001pt; font-size: 11pt; font-family: Calibri, sans-serif;" class=""><i class="">/usr/bin/ld: /home/bbwannabe/Documents/Nemesis/cPoisson/gcc/cPoissons.so: undefined reference to `blas_sgbmv_x_'<o:p class=""></o:p></i></div><div style="margin: 0in 0in 0.0001pt; font-size: 11pt; font-family: Calibri, sans-serif;" class=""><i class="">/usr/bin/ld: /home/bbwannabe/Documents/Nemesis/cPoisson/gcc/cPoissons.so: undefined reference to `blas_dgemv_x_'<o:p class=""></o:p></i></div><div style="margin: 0in 0in 0.0001pt; font-size: 11pt; font-family: Calibri, sans-serif;" class=""><i class="">/usr/bin/ld: /home/bbwannabe/Documents/Nemesis/cPoisson/gcc/cPoissons.so: undefined reference to `blas_zsymv_x_'<o:p class=""></o:p></i></div><div style="margin: 0in 0in 0.0001pt; font-size: 11pt; font-family: Calibri, sans-serif;" class="">/usr/bin/ld: /home/bbwannabe/Documents/Nemesis/cPoisson/gcc/cPoissons.so: undefined reference to `blas_csymv_x_'<o:p class=""></o:p></div><div style="margin: 0in 0in 0.0001pt; font-size: 11pt; font-family: Calibri, sans-serif;" class="">/usr/bin/ld: /home/bbwannabe/Documents/Nemesis/cPoisson/gcc/cPoissons.so: undefined reference to `blas_ssymv2_x_'<o:p class=""></o:p></div><div style="margin: 0in 0in 0.0001pt; font-size: 11pt; font-family: Calibri, sans-serif;" class="">/usr/bin/ld: /home/bbwannabe/Documents/Nemesis/cPoisson/gcc/cPoissons.so: undefined reference to `blas_ssymv_x_'<o:p class=""></o:p></div><div style="margin: 0in 0in 0.0001pt; font-size: 11pt; font-family: Calibri, sans-serif;" class="">/usr/bin/ld: /home/bbwannabe/Documents/Nemesis/cPoisson/gcc/cPoissons.so: undefined reference to `blas_zgemv2_x_'<o:p class=""></o:p></div><div style="margin: 0in 0in 0.0001pt; font-size: 11pt; font-family: Calibri, sans-serif;" class="">/usr/bin/ld: /home/bbwannabe/Documents/Nemesis/cPoisson/gcc/cPoissons.so: undefined reference to `blas_dsymv2_x_'<o:p class=""></o:p></div><div style="margin: 0in 0in 0.0001pt; font-size: 11pt; font-family: Calibri, sans-serif;" class="">/usr/bin/ld: /home/bbwannabe/Documents/Nemesis/cPoisson/gcc/cPoissons.so: undefined reference to `blas_zhemv_x_'<o:p class=""></o:p></div><div style="margin: 0in 0in 0.0001pt; font-size: 11pt; font-family: Calibri, sans-serif;" class="">/usr/bin/ld: /home/bbwannabe/Documents/Nemesis/cPoisson/gcc/cPoissons.so: undefined reference to `blas_zgbmv2_x_'<o:p class=""></o:p></div><div style="margin: 0in 0in 0.0001pt; font-size: 11pt; font-family: Calibri, sans-serif;" class="">/usr/bin/ld: /home/bbwannabe/Documents/Nemesis/cPoisson/gcc/cPoissons.so: undefined reference to `blas_sgemv2_x_'<o:p class=""></o:p></div><div style="margin: 0in 0in 0.0001pt; font-size: 11pt; font-family: Calibri, sans-serif;" class="">/usr/bin/ld: /home/bbwannabe/Documents/Nemesis/cPoisson/gcc/cPoissons.so: undefined reference to `blas_chemv_x_'<o:p class=""></o:p></div><div style="margin: 0in 0in 0.0001pt; font-size: 11pt; font-family: Calibri, sans-serif;" class="">/usr/bin/ld: /home/bbwannabe/Documents/Nemesis/cPoisson/gcc/cPoissons.so: undefined reference to `blas_dgemv2_x_'<o:p class=""></o:p></div><div style="margin: 0in 0in 0.0001pt; font-size: 11pt; font-family: Calibri, sans-serif;" class="">/usr/bin/ld: /home/bbwannabe/Documents/Nemesis/cPoisson/gcc/cPoissons.so: undefined reference to `blas_cgemv2_x_'<o:p class=""></o:p></div><div style="margin: 0in 0in 0.0001pt; font-size: 11pt; font-family: Calibri, sans-serif;" class="">/usr/bin/ld: /home/bbwannabe/Documents/Nemesis/cPoisson/gcc/cPoissons.so: undefined reference to `blas_sgbmv2_x_'<o:p class=""></o:p></div><div style="margin: 0in 0in 0.0001pt; font-size: 11pt; font-family: Calibri, sans-serif;" class="">/usr/bin/ld: /home/bbwannabe/Documents/Nemesis/cPoisson/gcc/cPoissons.so: undefined reference to `blas_zgbmv_x_'<o:p class=""></o:p></div><div style="margin: 0in 0in 0.0001pt; font-size: 11pt; font-family: Calibri, sans-serif;" class="">/usr/bin/ld: /home/bbwannabe/Documents/Nemesis/cPoisson/gcc/cPoissons.so: undefined reference to `blas_dgbmv_x_'<o:p class=""></o:p></div><div style="margin: 0in 0in 0.0001pt; font-size: 11pt; font-family: Calibri, sans-serif;" class="">/usr/bin/ld: /home/bbwannabe/Documents/Nemesis/cPoisson/gcc/cPoissons.so: undefined reference to `blas_zhemv2_x_'<o:p class=""></o:p></div><div style="margin: 0in 0in 0.0001pt; font-size: 11pt; font-family: Calibri, sans-serif;" class="">/usr/bin/ld: /home/bbwannabe/Documents/Nemesis/cPoisson/gcc/cPoissons.so: undefined reference to `blas_zsymv2_x_'<o:p class=""></o:p></div><div style="margin: 0in 0in 0.0001pt; font-size: 11pt; font-family: Calibri, sans-serif;" class="">/usr/bin/ld: /home/bbwannabe/Documents/Nemesis/cPoisson/gcc/cPoissons.so: undefined reference to `blas_dsymv_x_'<o:p class=""></o:p></div><div style="margin: 0in 0in 0.0001pt; font-size: 11pt; font-family: Calibri, sans-serif;" class="">/usr/bin/ld: /home/bbwannabe/Documents/Nemesis/cPoisson/gcc/cPoissons.so: undefined reference to `blas_dgbmv2_x_'<o:p class=""></o:p></div><div style="margin: 0in 0in 0.0001pt; font-size: 11pt; font-family: Calibri, sans-serif;" class="">/usr/bin/ld: /home/bbwannabe/Documents/Nemesis/cPoisson/gcc/cPoissons.so: undefined reference to `blas_cgemv_x_'<o:p class=""></o:p></div><div style="margin: 0in 0in 0.0001pt; font-size: 11pt; font-family: Calibri, sans-serif;" class="">collect2: error: ld returned 1 exit status<o:p class=""></o:p></div><div style="margin: 0in 0in 0.0001pt; font-size: 11pt; font-family: Calibri, sans-serif;" class="">make: *** [makefile:6: sPoisson3D] Error 1</div></div></div></blockquote></div><br class=""></div></body></html>