Backport GCC 4.5+ --enable-linker-build-id option.

gcc/configure

Index: gcc/configure
diff --git a/gcc/configure b/gcc/configure
index 9054b98983e7557deecb151bda98b423883ecd1b..21530e9d1605dd8d44706f33117abd80be133236 100755
--- a/gcc/configure
+++ b/gcc/configure
@@ -1078,6 +1078,8 @@ Optional Features:
   --enable-fast-install[=PKGS]
                           optimize for fast installation [default=yes]
   --disable-libtool-lock  avoid locking (might break parallel builds)
+  --enable-linker-build-id
+                          compiler will always pass --build-id to linker
   --enable-maintainer-mode
                           enable make rules and dependencies not useful
                           (and sometimes confusing) to the casual installer
@@ -24214,6 +24216,56 @@ _ACEOF
     ;;
 esac
 
+echo "$as_me:$LINENO: checking linker --build-id support" >&5
+echo $ECHO_N "checking linker --build-id support... $ECHO_C" >&6
+if test "${gcc_cv_ld_buildid+set}" = set; then
+  echo $ECHO_N "(cached) $ECHO_C" >&6
+else
+  gcc_cv_ld_buildid=no
+  if test $in_tree_ld = yes ; then
+    if test "$gcc_cv_gld_major_version" -eq 2 -a \
+       "$gcc_cv_gld_minor_version" -ge 18 -o \
+       "$gcc_cv_gld_major_version" -gt 2 \
+       && test $in_tree_ld_is_elf = yes; then
+      gcc_cv_ld_buildid=yes
+    fi
+  elif test x$gcc_cv_ld != x; then
+    if $gcc_cv_ld --help 2>/dev/null | grep build-id > /dev/null; then
+      gcc_cv_ld_buildid=yes
+    fi
+  fi
+fi
+echo "$as_me:$LINENO: result: $gcc_cv_ld_buildid" >&5
+echo "${ECHO_T}$gcc_cv_ld_buildid" >&6
+if test x"$gcc_cv_ld_buildid" = xyes; then
+
+cat >>confdefs.h <<\_ACEOF
+#define HAVE_LD_BUILDID 1
+_ACEOF
+
+fi
+
+# Check whether --enable-linker-build-id or --disable-linker-build-id was given.
+if test "${enable_linker_build_id+set}" = set; then
+  enableval="$enable_linker_build_id"
+
+else
+  enable_linker_build_id=no
+fi;
+
+if test x"$enable_linker_build_id" = xyes; then
+  if test x"$gcc_cv_ld_buildid" = xyes; then
+
+cat >>confdefs.h <<\_ACEOF
+#define ENABLE_LD_BUILDID 1
+_ACEOF
+
+  else
+    { echo "$as_me:$LINENO: WARNING: --build-id is not supported by your linker; --enable-linker-build-id ignored" >&5
+echo "$as_me: WARNING: --build-id is not supported by your linker; --enable-linker-build-id ignored" >&2;}
+  fi
+fi
+
 echo "$as_me:$LINENO: checking linker --sysroot support" >&5
 echo $ECHO_N "checking linker --sysroot support... $ECHO_C" >&6
 if test "${gcc_cv_ld_sysroot+set}" = set; then