-----Original Message-----
From: Smith-Rowland, Edward M
Sent: Thu 4/3/2008 5:06 PM
To: gcc-help@xxxxxxxxxxx
Cc: Smith-Rowland, Edward M; 3dw4rd@xxxxxxxxxxx
Subject: gfortran and -fvisibility
I am having trouble with symbol visibility with gfortran on Linux x86_64.
It looks like -fvisibility=hidden doesn't work.
[ed@alion7 tirem-3.2]$ gfortran -v
Using built-in specs.
Target: x86_64-redhat-linux
Configured with: ../configure --prefix=/usr --mandir=/usr/share/man --infodir=/usr/share/info --enable-shared --enable-threads=posix --enable-checking=release --with-system-zlib --enable-__cxa_atexit --disable-libunwind-exceptions --enable-libgcj-multifile --enable-languages=c,c++,objc,obj-c++,java,fortran,ada --enable-java-awt=gtk --disable-dssi --enable-plugin --with-java-home=/usr/lib/jvm/java-1.4.2-gcj-1.4.2.0/jre --with-cpu=generic --host=x86_64-redhat-linux
Thread model: posix
gcc version 4.1.2 20070626 (Red Hat 4.1.2-14)
So I copied and translated a gcc.dg/visibility-9.c to Fortran for a small test case.
I compiled with gfortran to a shared library (x86_64 ELF Linux etc.).
visibility-1.f90
--------------------------------------------------------------------
! Test that -fvisibility works.
! { dg-do compile }
! { dg-require-visibility "" }
! { dg-options "-fvisibility=hidden" }
! { dg-final { scan-hidden "foo" } }
subroutine foo
end subroutine
--------------------------------------------------------------------
[ed@alion7 ~]$ gfortran -shared -fvisibility=default -fPIC -o visibility-1.so visibility-1.f90
[ed@alion7 ~]$ nm -C -D visibility-1.so
w _Jv_RegisterClasses
00000000002007c8 A __bss_start
w __cxa_finalize
w __gmon_start__
00000000002007c8 A _edata
00000000002007d8 A _end
0000000000000548 T _fini
00000000000003f0 T _init
00000000000004fc T foo_
The "foo_" at the end is teh bad thing.
I haven't checked a gfortran less than 4.1 but g77 as of gcc-3.4 supports visibility.
I've checked with an almost release gcc-4.3 and visibility still didn't work.
Is anyone else seeing a problem?
I'll check PPC MacOS and i32 Cygwin when I get home.
Ed Smith-Rowland
-------------------------------------------------------
I just verified this on PPC MacOSX:
MacOSX:~ ed$ bin-4.3/bin/gfortran -v
Using built-in specs.
Target: powerpc-apple-darwin7.9.0
Configured with: ../gcc/configure --prefix=/Users/ed/bin-4.3 --enable-languages=c,c++,objc,obj-c++,fortran,treelang
Thread model: posix
gcc version 4.3.0 20071116 (experimental) (GCC)
The results of nm:
MacOSX:~ ed$ bin-4.3/bin/gfortran -dynamiclib -fvisibility=default -fPIC -o visibility-1.dylib visibility-1.f90
MacOSX:~ ed$ nm visibility-1.dylib
...
visibility-1.dylib(ccsE7pf3.o):
00001db0 T _foo_
...
