Re: Link tests after GCC_NO_EXECUTABLES

[Rask Ingemann Lambertsen <rask@sygehus.dk>]

On Thu, Nov 29, 2007 at 10:05:54PM +0000, Richard Sandiford wrote:

> Even though current mainline can build libgfortran, all tests fail for
> simulator testing, and I'm not sure whether you could get it work for
> bare-metal boards or not. 

   It works on arm-unknown-elf, v850-unknown-elf and frv-unknown-elf:
http://gcc.gnu.org/ml/gcc-testresults/2007-11/msg01428.html
http://gcc.gnu.org/ml/gcc-testresults/2007-11/msg01468.html
http://gcc.gnu.org/ml/gcc-testresults/2007-11/msg00427.html

   Some work has been and is being done in this area:
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21185

   Hans, you showed gfortran results for cris-elf, but we don't seem to be
building gfortran for the cris?

> It sounds like we've agreed that, if we want
> to support libgfortran on targets like mips*-elf*, we should use
> libstd++-like with_newlib checks there too.

   Likewise for the other target libraries - how many did you test?

   I tried a build of sparc-unknown-elf (which is know to fail link tests)
with "with_newlib" checks around the AC_LIBTOOL_DLOPEN macro in both
libstdc++ and libgfortran. It fails because:

configure:3391: checking whether symbol versioning is supported
configure:3402: error: Link tests are not allowed after GCC_NO_EXECUTABLES.

With this patch I get marginally further:

Index: libgfortran/configure.ac
===================================================================
--- libgfortran/configure.ac    (revision 130442)
+++ libgfortran/configure.ac    (working copy)
@@ -142,12 +142,14 @@
   global: *foo*; bar; local: *;
 };
 EOF
-save_LDFLAGS="$LDFLAGS"
-LDFLAGS="$LDFLAGS -fPIC -shared -Wl,--version-script,./conftest.map"
-AC_TRY_LINK([int foo;],[],[gfortran_use_symver=yes],[gfortran_use_symver=no])
-LDFLAGS="$save_LDFLAGS"
-AC_MSG_RESULT($gfortran_use_symver)
-AM_CONDITIONAL(LIBGFOR_USE_SYMVER, [test "x$gfortran_use_symver" = xyes])
+if test "x${with_newlib}" != "xyes"; then
+  save_LDFLAGS="$LDFLAGS"
+  LDFLAGS="$LDFLAGS -fPIC -shared -Wl,--version-script,./conftest.map"
+  AC_TRY_LINK([int foo;],[],[gfortran_use_symver=yes],[gfortran_use_symver=no])
+  LDFLAGS="$save_LDFLAGS"
+  AC_MSG_RESULT($gfortran_use_symver)
+  AM_CONDITIONAL(LIBGFOR_USE_SYMVER, [test "x$gfortran_use_symver" = xyes])
+fi

 # Find other programs we need.
 AC_CHECK_TOOL(AS, as)
@@ -158,7 +160,9 @@

 # Configure libtool
 #AC_MSG_NOTICE([====== Starting libtool configuration])
-AC_LIBTOOL_DLOPEN
+if test "x${with_newlib}" != "xyes"; then
+  AC_LIBTOOL_DLOPEN
+fi
 AM_PROG_LIBTOOL
 AC_SUBST(enable_shared)
 AC_SUBST(enable_static)

configure:18061: checking for getrusage
configure:18067: error: Link tests are not allowed after GCC_NO_EXECUTABLES.

> Perhaps we should turn target-libgfortran off by default for mips*-elf*.

   No. There is a point in excercising the compiler: Testing. In most cases,
you don't find problems with the compiler until you try to compile something.

> @@ -2410,6 +2368,16 @@ fi
>  
>  # Search for other target-specific linker scripts and such.
>  case "${target}" in
> +  m32c-*-* )
> +    if test -d ${srcdir}/libgloss/m32c; then
> +      # This is for crt0.o
> +      FLAGS_FOR_TARGET=$FLAGS_FOR_TARGET' -B$$r/$(TARGET_SUBDIR)/libgloss/m32c'
> +      # This is for r8c.ld
> +      FLAGS_FOR_TARGET=$FLAGS_FOR_TARGET' -L$$r/$(TARGET_SUBDIR)/libgloss/m32c'
> +      # This is for libnosys.a
> +      FLAGS_FOR_TARGET=$FLAGS_FOR_TARGET' -L$$r/$(TARGET_SUBDIR)/libgloss/libnosys'
> +    fi
> +    ;;
>    mep*)
>      FLAGS_FOR_TARGET="$FLAGS_FOR_TARGET -mlibrary"
>      ;;

   This hunk should be left out. And I would prefer that we don't revert the
patch until everything that builds with the patch also builds without the
patch.

   Additionally, I would prefer we call the option something else than
--with-newlib - suppose there's no newlib for the target. At least the AVR
uses something else.

-- 
Rask Ingemann Lambertsen
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