[gcc r13-2517] [gdb/build] Fix build breaker with --enable-shared

[Tom de Vries <vries@gcc.gnu.org>]

https://gcc.gnu.org/g:04bb15e48ef8dd3d6a5ff30723c603cef3e0a3c6

commit r13-2517-g04bb15e48ef8dd3d6a5ff30723c603cef3e0a3c6
Author: Tom de Vries <tdevries@suse.de>
Date:   Wed Sep 7 13:19:05 2022 +0200

    [gdb/build] Fix build breaker with --enable-shared
    
    When building gdb with --enable-shared, I run into:
    ...
    ld: build/zlib/libz.a(libz_a-inffast.o): relocation R_X86_64_32S against \
      `.rodata' can not be used when making a shared object; recompile with -fPIC
    ld: build/zlib/libz.a(libz_a-inflate.o): warning: relocation against \
      `inflateResetKeep' in read-only section `.text'
    collect2: error: ld returned 1 exit status
    make[3]: *** [libbfd.la] Error 1
    ...
    
    This is a regression since commit a08bdb159bb ("[gdb/build] Fix gdbserver
    build with -fsanitize=thread").
    
    The problem is that a single case statement in configure is shared to handle
    special requirements for both the host libiberty and host zlib, which has the
    effect that only one is handled.
    
    Fix this by handling libiberty and zlib each in its own case statement.
    
    Build on x86_64-linux, with and without --enable-shared.
    
    ChangeLog:
    
    2022-09-07  Tom de Vries  <tdevries@suse.de>
    
            * configure.ac: Set extra_host_libiberty_configure_flags and
            extra_host_zlib_configure_flags in separate case statements.
            * configure: Regenerate.

Diff:
---
 configure    | 8 ++++++--
 configure.ac | 8 ++++++--
 2 files changed, 12 insertions(+), 4 deletions(-)

diff --git a/configure b/configure
index e90b8df217d..e7604dc6ff0 100755
--- a/configure
+++ b/configure
@@ -9188,13 +9188,18 @@ fi
 
 # Sometimes we have special requirements for the host libiberty.
 extra_host_libiberty_configure_flags=
-extra_host_zlib_configure_flags=
 case " $configdirs " in
   *" lto-plugin "* | *" libcc1 "* | *" gdbserver "*)
     # When these are to be built as shared libraries, the same applies to
     # libiberty.
     extra_host_libiberty_configure_flags=--enable-shared
     ;;
+esac
+
+
+# Sometimes we have special requirements for the host zlib.
+extra_host_zlib_configure_flags=
+case " $configdirs " in
   *" bfd "*)
     # When bfd is to be built as a shared library, the same applies to
     # zlib.
@@ -9205,7 +9210,6 @@ case " $configdirs " in
 esac
 
 
-
 # Produce a warning message for the subdirs we can't configure.
 # This isn't especially interesting in the Cygnus tree, but in the individual
 # FSF releases, it's important to let people know when their machine isn't
diff --git a/configure.ac b/configure.ac
index 3ecb532138d..3cfd9b41fca 100644
--- a/configure.ac
+++ b/configure.ac
@@ -2439,13 +2439,18 @@ fi
 
 # Sometimes we have special requirements for the host libiberty.
 extra_host_libiberty_configure_flags=
-extra_host_zlib_configure_flags=
 case " $configdirs " in
   *" lto-plugin "* | *" libcc1 "* | *" gdbserver "*)
     # When these are to be built as shared libraries, the same applies to
     # libiberty.
     extra_host_libiberty_configure_flags=--enable-shared
     ;;
+esac
+AC_SUBST(extra_host_libiberty_configure_flags)
+
+# Sometimes we have special requirements for the host zlib.
+extra_host_zlib_configure_flags=
+case " $configdirs " in
   *" bfd "*)
     # When bfd is to be built as a shared library, the same applies to
     # zlib.
@@ -2454,7 +2459,6 @@ case " $configdirs " in
     fi
     ;;
 esac
-AC_SUBST(extra_host_libiberty_configure_flags)
 AC_SUBST(extra_host_zlib_configure_flags)
 
 # Produce a warning message for the subdirs we can't configure.