Re: [PATCH] Link to -lssp when available (fixes mingw build)

["Christian Biesinger via gdb-patches" <gdb-patches@sourceware.org>]

On Wed, Dec 18, 2019 at 12:14 PM Christian Biesinger
<cbiesinger@google.com> wrote:
>
> Recent mingw versions require -lssp when using _FORTIFY_SOURCE, which
> gdb does (in common-defs.h)
> https://github.com/msys2/MINGW-packages/issues/5868#issuecomment-544107564

I should have clarified: this is mingw64 (from msys2.org).

Also, I'd like to push this to the gdb 9 branch too, if that's ok.

Christian

> gdb/ChangeLog:
>
> 2019-12-18  Christian Biesinger  <cbiesinger@google.com>
>
>         * configure: Regenerate.
>         * gdbsupport/common.m4: Look for -lssp to fix mingw.
>
> gdb/gdbserver/ChangeLog:
>
> 2019-12-18  Christian Biesinger  <cbiesinger@google.com>
>
>         * configure: Regenerate.
>
> Change-Id: Ide6870ab57198219a2ef78bc675768a789ca2b1d
> ---
>  gdb/configure            | 57 ++++++++++++++++++++++++++++++++++++++++
>  gdb/gdbserver/configure  | 57 ++++++++++++++++++++++++++++++++++++++++
>  gdb/gdbsupport/common.m4 |  4 +++
>  3 files changed, 118 insertions(+)
>
> diff --git a/gdb/configure b/gdb/configure
> index 324eb50944..04ead07bc9 100755
> --- a/gdb/configure
> +++ b/gdb/configure
> @@ -13642,6 +13642,63 @@ cat >>confdefs.h <<_ACEOF
>  _ACEOF
>
>
> +      { $as_echo "$as_me:${as_lineno-$LINENO}: checking for library containing __memcpy_chk" >&5
> +$as_echo_n "checking for library containing __memcpy_chk... " >&6; }
> +if ${ac_cv_search___memcpy_chk+:} false; then :
> +  $as_echo_n "(cached) " >&6
> +else
> +  ac_func_search_save_LIBS=$LIBS
> +cat confdefs.h - <<_ACEOF >conftest.$ac_ext
> +/* end confdefs.h.  */
> +
> +/* Override any GCC internal prototype to avoid an error.
> +   Use char because int might match the return type of a GCC
> +   builtin and then its argument prototype would still apply.  */
> +#ifdef __cplusplus
> +extern "C"
> +#endif
> +char __memcpy_chk ();
> +int
> +main ()
> +{
> +return __memcpy_chk ();
> +  ;
> +  return 0;
> +}
> +_ACEOF
> +for ac_lib in '' ssp; do
> +  if test -z "$ac_lib"; then
> +    ac_res="none required"
> +  else
> +    ac_res=-l$ac_lib
> +    LIBS="-l$ac_lib  $ac_func_search_save_LIBS"
> +  fi
> +  if ac_fn_c_try_link "$LINENO"; then :
> +  ac_cv_search___memcpy_chk=$ac_res
> +fi
> +rm -f core conftest.err conftest.$ac_objext \
> +    conftest$ac_exeext
> +  if ${ac_cv_search___memcpy_chk+:} false; then :
> +  break
> +fi
> +done
> +if ${ac_cv_search___memcpy_chk+:} false; then :
> +
> +else
> +  ac_cv_search___memcpy_chk=no
> +fi
> +rm conftest.$ac_ext
> +LIBS=$ac_func_search_save_LIBS
> +fi
> +{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_search___memcpy_chk" >&5
> +$as_echo "$ac_cv_search___memcpy_chk" >&6; }
> +ac_res=$ac_cv_search___memcpy_chk
> +if test "$ac_res" != no; then :
> +  test "$ac_res" = "none required" || LIBS="$ac_res $LIBS"
> +
> +fi
> +
> +
>    # Check for std::thread.  This does not work on some platforms, like
>    # mingw and DJGPP.
>    ac_ext=cpp
> diff --git a/gdb/gdbserver/configure b/gdb/gdbserver/configure
> index ccffde80ed..9f1cc70fda 100755
> --- a/gdb/gdbserver/configure
> +++ b/gdb/gdbserver/configure
> @@ -7034,6 +7034,63 @@ cat >>confdefs.h <<_ACEOF
>  _ACEOF
>
>
> +      { $as_echo "$as_me:${as_lineno-$LINENO}: checking for library containing __memcpy_chk" >&5
> +$as_echo_n "checking for library containing __memcpy_chk... " >&6; }
> +if ${ac_cv_search___memcpy_chk+:} false; then :
> +  $as_echo_n "(cached) " >&6
> +else
> +  ac_func_search_save_LIBS=$LIBS
> +cat confdefs.h - <<_ACEOF >conftest.$ac_ext
> +/* end confdefs.h.  */
> +
> +/* Override any GCC internal prototype to avoid an error.
> +   Use char because int might match the return type of a GCC
> +   builtin and then its argument prototype would still apply.  */
> +#ifdef __cplusplus
> +extern "C"
> +#endif
> +char __memcpy_chk ();
> +int
> +main ()
> +{
> +return __memcpy_chk ();
> +  ;
> +  return 0;
> +}
> +_ACEOF
> +for ac_lib in '' ssp; do
> +  if test -z "$ac_lib"; then
> +    ac_res="none required"
> +  else
> +    ac_res=-l$ac_lib
> +    LIBS="-l$ac_lib  $ac_func_search_save_LIBS"
> +  fi
> +  if ac_fn_c_try_link "$LINENO"; then :
> +  ac_cv_search___memcpy_chk=$ac_res
> +fi
> +rm -f core conftest.err conftest.$ac_objext \
> +    conftest$ac_exeext
> +  if ${ac_cv_search___memcpy_chk+:} false; then :
> +  break
> +fi
> +done
> +if ${ac_cv_search___memcpy_chk+:} false; then :
> +
> +else
> +  ac_cv_search___memcpy_chk=no
> +fi
> +rm conftest.$ac_ext
> +LIBS=$ac_func_search_save_LIBS
> +fi
> +{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_search___memcpy_chk" >&5
> +$as_echo "$ac_cv_search___memcpy_chk" >&6; }
> +ac_res=$ac_cv_search___memcpy_chk
> +if test "$ac_res" != no; then :
> +  test "$ac_res" = "none required" || LIBS="$ac_res $LIBS"
> +
> +fi
> +
> +
>    # Check for std::thread.  This does not work on some platforms, like
>    # mingw and DJGPP.
>    ac_ext=cpp
> diff --git a/gdb/gdbsupport/common.m4 b/gdb/gdbsupport/common.m4
> index c61753fb8e..eb66ec3731 100644
> --- a/gdb/gdbsupport/common.m4
> +++ b/gdb/gdbsupport/common.m4
> @@ -37,6 +37,10 @@ AC_DEFUN([GDB_AC_COMMON], [
>
>    AC_CHECK_DECLS([strstr])
>
> +  dnl Recent mingw requires -lssp when using _FORTIFY_SOURCE, which we do
> +  dnl (see gdbsupport/common-defs.h)
> +  AC_SEARCH_LIBS(__memcpy_chk, ssp)
> +
>    # Check for std::thread.  This does not work on some platforms, like
>    # mingw and DJGPP.
>    AC_LANG_PUSH([C++])
> --
> 2.24.1.735.g03f4e72817-goog
>