Remove the dead --disable-visiblity configure option

At the same time, document --disable-Bsymbolic.

configure.ac

@@ -224,10 +224,6 @@ AC_ARG_ENABLE(rebuilds,
               [AC_HELP_STRING([--disable-rebuilds],
                               [disable all source autogeneration rules])],,
               [enable_rebuilds=yes])
-AC_ARG_ENABLE(visibility,
-              [AC_HELP_STRING([--disable-visibility],
-                              [don't use ELF visibility attributes])],,
-              [enable_visibility=yes])
 
 if test "x$enable_threads" != "xyes"; then
   enable_threads=no
@@ -296,10 +292,6 @@ else
   fi
 fi
 
-if test "x$enable_visibility" = "xno"; then
-  GLIB_DEBUG_FLAGS="$GLIB_DEBUG_FLAGS -DDISABLE_VISIBILITY"
-fi
-
 # Ensure MSVC-compatible struct packing convention is used when
 # compiling for Win32 with gcc.
 # What flag to depends on gcc version: gcc3 uses "-mms-bitfields", while

docs/reference/glib/building.sgml

@@ -232,8 +232,8 @@ How to compile GLib itself
              <arg>--enable-included-printf</arg>
           </group>
 	  <group>
-             <arg>--disable-visibility</arg>
-             <arg>--enable-visibility</arg>
+             <arg>--disable-Bsymbolic</arg>
+             <arg>--enable-Bsymbolic</arg>
           </group>
           <group>
             <arg>--disable-gtk-doc</arg>
@@ -510,19 +510,18 @@ How to compile GLib itself
       </formalpara>
 
       <formalpara>
-         <title><systemitem>--disable-visibility</systemitem> and
-           <systemitem>--enable-visibility</systemitem></title>
+         <title><systemitem>--disable-Bsymbolic</systemitem> and
+           <systemitem>--enable-Bsymbolic</systemitem></title>
 
         <para>
-          By default, GLib uses ELF visibility attributes to optimize
-          PLT table entries if the compiler supports ELF visibility
-          attributes. A side-effect of the way in which this is currently
-          implemented is that any  header change forces a full
-          recompilation, and missing includes may go unnoticed.
-          Therefore, it makes sense to turn this feature off while
-          doing GLib development, even if the compiler supports ELF
-          visibility attributes. The <option>--disable-visibility</option>
-          option allows to do that.
+          By default, GLib uses the -Bsymbolic-functions linker
+          flag to avoid intra-library PLT jumps. A side-effect
+          of this is that it is no longer possible to override
+          internal uses of GLib functions with
+          <envvar>LD_PRELOAD</envvar>. Therefore, it may make
+          sense to turn this feature off in some situations.
+          The <option>--disable-Bsymbolic</option> option allows
+          to do that.
         </para>
       </formalpara>
 

gthread/tests/1bit-mutex.c

@@ -26,9 +26,6 @@
    */
 
   /* side-step some glib build stuff */
-  #ifndef DISABLE_VISIBILITY
-  #define DISABLE_VISIBILITY
-  #endif
   #define GLIB_COMPILATION
 
   /* rebuild gbitlock.c without futex support,