Help with strange compiler error linking to GSL

[Lewis Hyatt]

Lee Rhodes wrote:

> Hello,
>   I have installed the GSL libs via setup and am trying to get the following
> example program to work:
> 
> #include <stdio.h>
> #include <gsl/gsl_sf_bessel.h>
> 
> int main (void)
>      {
>        double x = 5.0;
>        double y = gsl_sf_bessel_J0 (x);
>        printf ("J0(%g) = %.18e\n", x, y);
>        return 0;
>      }
> 
> The compiler/linker is able to locate the header ok, but the error message I
> get on the line that calls the function is:
> 
> 	undefined reference to `_gsl_sf_bessel_J0'
> 
> Somehow the function name got mangled with an added underscore, and of
> course, it doesn't exist.
> 

It compiles and links fine for me using "gcc t.cpp -lgsl". Are you sure 
you are putting -lgsl in the right place on the command line (ie, at the 
end)? If you are, try compiling with "gcc -v -v t.cpp -lgsl", here is 
that output for me:

$ gcc t.cpp -v -v -lgsl
Reading specs from /usr/lib/gcc/i686-pc-cygwin/3.4.4/specs
Configured with: 
/usr/build/package/orig/test.respin/gcc-3.4.4-3/configure --verbose 
--prefix=/usr --exec-prefix=/usr --sysconfdir=/etc --libdir=/usr/lib 
--libexecdir=/usr/lib --mandir=/usr/share/man --infodir=/usr/share/info 
--enable-languages=c,ada,c++,d,f77,pascal,java,objc --enable-nls 
--without-included-gettext --enable-version-specific-runtime-libs 
--without-x --enable-libgcj --disable-java-awt --with-system-zlib 
--enable-interpreter --disable-libgcj-debug --enable-threads=posix 
--enable-java-gc=boehm --disable-win32-registry --enable-sjlj-exceptions 
--enable-hash-synchronization --enable-libstdcxx-debug
Thread model: posix
gcc version 3.4.4 (cygming special, gdc 0.12, using dmd 0.125)
  /usr/lib/gcc/i686-pc-cygwin/3.4.4/cc1plus.exe -quiet -v -v 
-D__CYGWIN32__ -D__CYGWIN__ -Dunix -D__unix__ -D__unix -idirafter 
/usr/lib/gcc/i686-pc-cygwin/3.4.4/../../../../include/w32api -idirafter 
/usr/local/lib/../../include/w32api t.cpp -quiet -dumpbase t.cpp 
-mtune=pentiumpro -auxbase t -version -o 
/cygdrive/c/DOCUME~1/Lewis/LOCALS~1/Temp/cc1w4jdk.s
ignoring nonexistent directory 
"/usr/lib/gcc/i686-pc-cygwin/3.4.4/../../../../i686-pc-cygwin/include"
ignoring duplicate directory "/usr/local/lib/../../include/w32api"
#include "..." search starts here:
#include <...> search starts here:
  /usr/lib/gcc/i686-pc-cygwin/3.4.4/include/c++
  /usr/lib/gcc/i686-pc-cygwin/3.4.4/include/c++/i686-pc-cygwin
  /usr/lib/gcc/i686-pc-cygwin/3.4.4/include/c++/backward
  /usr/local/include
  /usr/lib/gcc/i686-pc-cygwin/3.4.4/include
  /usr/include
  /usr/lib/gcc/i686-pc-cygwin/3.4.4/../../../../include/w32api
End of search list.
GNU C++ version 3.4.4 (cygming special, gdc 0.12, using dmd 0.125) 
(i686-pc-cygwin)
         compiled by GNU C version 3.4.4 (cygming special, gdc 0.12, 
using dmd 0.125).
GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072
t.cpp:10:7: warning: no newline at end of file
 
/usr/lib/gcc/i686-pc-cygwin/3.4.4/../../../../i686-pc-cygwin/bin/as.exe 
-o /cygdrive/c/DOCUME~1/Lewis/LOCALS~1/Temp/ccGPvaYJ.o 
/cygdrive/c/DOCUME~1/Lewis/LOCALS~1/Temp/cc1w4jdk.s
  /usr/lib/gcc/i686-pc-cygwin/3.4.4/collect2.exe -Bdynamic 
--dll-search-prefix=cyg 
/usr/lib/gcc/i686-pc-cygwin/3.4.4/../../../crt0.o -L/usr/local/lib 
-L/usr/lib/gcc/i686-pc-cygwin/3.4.4 -L/usr/lib/gcc/i686-pc-cygwin/3.4.4 
-L/usr/lib/gcc/i686-pc-cygwin/3.4.4/../../.. 
/cygdrive/c/DOCUME~1/Lewis/LOCALS~1/Temp/ccGPvaYJ.o -lgsl -lgcc -lcygwin 
-luser32 -lkernel32 -ladvapi32 -lshell32 -lgcc


It also works fine with g++ for me.

-Lewis


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