ld: add --package-metadata

Generate a .note.package FDO package metadata ELF note, following
the spec: https://systemd.io/ELF_PACKAGE_METADATA/

If the jansson library is available at build time (and it is explicitly
enabled), link ld to it, and use it to validate that the input is
correct JSON, to avoid writing garbage to the file. The
configure option --enable-jansson has to be used to explicitly enable
it (error out when not found). This allows bootstrappers (or others who
are not interested) to seamlessly skip it without issues.

1 files changed, 268 insertions, 2 deletions

diff --git a/ld/configure b/ld/configure
index 16db825..80db525 100755
--- a/ld/configure
+++ b/ld/configure
@@ -677,6 +677,11 @@ WARN_WRITE_STRINGS
 NO_WERROR
 WARN_CFLAGS_FOR_BUILD
 WARN_CFLAGS
+JANSSON_LIBS
+JANSSON_CFLAGS
+PKG_CONFIG_LIBDIR
+PKG_CONFIG_PATH
+PKG_CONFIG
 enable_libctf
 ENABLE_LIBCTF_FALSE
 ENABLE_LIBCTF_TRUE
@@ -845,6 +850,7 @@ enable_error_handling_script
 enable_default_hash_style
 enable_initfini_array
 enable_libctf
+enable_jansson
 enable_werror
 enable_build_warnings
 enable_nls
@@ -863,6 +869,11 @@ CXXFLAGS
 CCC
 CPP
 CXXCPP
+PKG_CONFIG
+PKG_CONFIG_PATH
+PKG_CONFIG_LIBDIR
+JANSSON_CFLAGS
+JANSSON_LIBS
 YACC
 YFLAGS'
 
@@ -1527,6 +1538,7 @@ Optional Features:
                           use this default hash style
   --disable-initfini-array do not use .init_array/.fini_array sections
   --enable-libctf         Handle .ctf type-info sections [default=yes]
+  --enable-jansson        enable jansson [default=no]
   --enable-werror         treat compile warnings as errors
   --enable-build-warnings enable build-time compiler warnings
   --disable-nls           do not use Native Language Support
@@ -1553,6 +1565,15 @@ Some influential environment variables:
   CXXFLAGS    C++ compiler flags
   CPP         C preprocessor
   CXXCPP      C++ preprocessor
+  PKG_CONFIG  path to pkg-config utility
+  PKG_CONFIG_PATH
+              directories to add to pkg-config's search path
+  PKG_CONFIG_LIBDIR
+              path overriding pkg-config's built-in search path
+  JANSSON_CFLAGS
+              C compiler flags for JANSSON, overriding pkg-config
+  JANSSON_LIBS
+              linker flags for JANSSON, overriding pkg-config
   YACC        The `Yet Another Compiler Compiler' implementation to use.
               Defaults to the first program found out of: `bison -y', `byacc',
               `yacc'.
@@ -11470,7 +11491,7 @@ else
   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<_LT_EOF
-#line 11473 "configure"
+#line 11494 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H
@@ -11576,7 +11597,7 @@ else
   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<_LT_EOF
-#line 11579 "configure"
+#line 11600 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H
@@ -15555,6 +15576,251 @@ fi
 
 
 
+# Used to validate --package-metadata= input. Disabled by default.
+# Check whether --enable-jansson was given.
+if test "${enable_jansson+set}" = set; then :
+  enableval=$enable_jansson; enable_jansson=$enableval
+else
+  enable_jansson="no"
+fi
+
+
+if test "x$enable_jansson" != "xno"; then
+
+
+
+
+
+
+
+if test "x$ac_cv_env_PKG_CONFIG_set" != "xset"; then
+	if test -n "$ac_tool_prefix"; then
+  # Extract the first word of "${ac_tool_prefix}pkg-config", so it can be a program name with args.
+set dummy ${ac_tool_prefix}pkg-config; ac_word=$2
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for $ac_word" >&5
+$as_echo_n "checking for $ac_word... " >&6; }
+if ${ac_cv_path_PKG_CONFIG+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  case $PKG_CONFIG in
+  [\\/]* | ?:[\\/]*)
+  ac_cv_path_PKG_CONFIG="$PKG_CONFIG" # Let the user override the test with a path.
+  ;;
+  *)
+  as_save_IFS=$IFS; IFS=$PATH_SEPARATOR
+for as_dir in $PATH
+do
+  IFS=$as_save_IFS
+  test -z "$as_dir" && as_dir=.
+    for ac_exec_ext in '' $ac_executable_extensions; do
+  if as_fn_executable_p "$as_dir/$ac_word$ac_exec_ext"; then
+    ac_cv_path_PKG_CONFIG="$as_dir/$ac_word$ac_exec_ext"
+    $as_echo "$as_me:${as_lineno-$LINENO}: found $as_dir/$ac_word$ac_exec_ext" >&5
+    break 2
+  fi
+done
+  done
+IFS=$as_save_IFS
+
+  ;;
+esac
+fi
+PKG_CONFIG=$ac_cv_path_PKG_CONFIG
+if test -n "$PKG_CONFIG"; then
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: $PKG_CONFIG" >&5
+$as_echo "$PKG_CONFIG" >&6; }
+else
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
+$as_echo "no" >&6; }
+fi
+
+
+fi
+if test -z "$ac_cv_path_PKG_CONFIG"; then
+  ac_pt_PKG_CONFIG=$PKG_CONFIG
+  # Extract the first word of "pkg-config", so it can be a program name with args.
+set dummy pkg-config; ac_word=$2
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for $ac_word" >&5
+$as_echo_n "checking for $ac_word... " >&6; }
+if ${ac_cv_path_ac_pt_PKG_CONFIG+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  case $ac_pt_PKG_CONFIG in
+  [\\/]* | ?:[\\/]*)
+  ac_cv_path_ac_pt_PKG_CONFIG="$ac_pt_PKG_CONFIG" # Let the user override the test with a path.
+  ;;
+  *)
+  as_save_IFS=$IFS; IFS=$PATH_SEPARATOR
+for as_dir in $PATH
+do
+  IFS=$as_save_IFS
+  test -z "$as_dir" && as_dir=.
+    for ac_exec_ext in '' $ac_executable_extensions; do
+  if as_fn_executable_p "$as_dir/$ac_word$ac_exec_ext"; then
+    ac_cv_path_ac_pt_PKG_CONFIG="$as_dir/$ac_word$ac_exec_ext"
+    $as_echo "$as_me:${as_lineno-$LINENO}: found $as_dir/$ac_word$ac_exec_ext" >&5
+    break 2
+  fi
+done
+  done
+IFS=$as_save_IFS
+
+  ;;
+esac
+fi
+ac_pt_PKG_CONFIG=$ac_cv_path_ac_pt_PKG_CONFIG
+if test -n "$ac_pt_PKG_CONFIG"; then
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_pt_PKG_CONFIG" >&5
+$as_echo "$ac_pt_PKG_CONFIG" >&6; }
+else
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
+$as_echo "no" >&6; }
+fi
+
+  if test "x$ac_pt_PKG_CONFIG" = x; then
+    PKG_CONFIG=""
+  else
+    case $cross_compiling:$ac_tool_warned in
+yes:)
+{ $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: using cross tools not prefixed with host triplet" >&5
+$as_echo "$as_me: WARNING: using cross tools not prefixed with host triplet" >&2;}
+ac_tool_warned=yes ;;
+esac
+    PKG_CONFIG=$ac_pt_PKG_CONFIG
+  fi
+else
+  PKG_CONFIG="$ac_cv_path_PKG_CONFIG"
+fi
+
+fi
+if test -n "$PKG_CONFIG"; then
+	_pkg_min_version=0.9.0
+	{ $as_echo "$as_me:${as_lineno-$LINENO}: checking pkg-config is at least version $_pkg_min_version" >&5
+$as_echo_n "checking pkg-config is at least version $_pkg_min_version... " >&6; }
+	if $PKG_CONFIG --atleast-pkgconfig-version $_pkg_min_version; then
+		{ $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
+$as_echo "yes" >&6; }
+	else
+		{ $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
+$as_echo "no" >&6; }
+		PKG_CONFIG=""
+	fi
+fi
+  if test -n "$PKG_CONFIG"; then :
+
+
+pkg_failed=no
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for jansson" >&5
+$as_echo_n "checking for jansson... " >&6; }
+
+if test -n "$JANSSON_CFLAGS"; then
+    pkg_cv_JANSSON_CFLAGS="$JANSSON_CFLAGS"
+ elif test -n "$PKG_CONFIG"; then
+    if test -n "$PKG_CONFIG" && \
+    { { $as_echo "$as_me:${as_lineno-$LINENO}: \$PKG_CONFIG --exists --print-errors \"jansson\""; } >&5
+  ($PKG_CONFIG --exists --print-errors "jansson") 2>&5
+  ac_status=$?
+  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; }; then
+  pkg_cv_JANSSON_CFLAGS=`$PKG_CONFIG --cflags "jansson" 2>/dev/null`
+		      test "x$?" != "x0" && pkg_failed=yes
+else
+  pkg_failed=yes
+fi
+ else
+    pkg_failed=untried
+fi
+if test -n "$JANSSON_LIBS"; then
+    pkg_cv_JANSSON_LIBS="$JANSSON_LIBS"
+ elif test -n "$PKG_CONFIG"; then
+    if test -n "$PKG_CONFIG" && \
+    { { $as_echo "$as_me:${as_lineno-$LINENO}: \$PKG_CONFIG --exists --print-errors \"jansson\""; } >&5
+  ($PKG_CONFIG --exists --print-errors "jansson") 2>&5
+  ac_status=$?
+  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; }; then
+  pkg_cv_JANSSON_LIBS=`$PKG_CONFIG --libs "jansson" 2>/dev/null`
+		      test "x$?" != "x0" && pkg_failed=yes
+else
+  pkg_failed=yes
+fi
+ else
+    pkg_failed=untried
+fi
+
+if test $pkg_failed = no; then
+  pkg_save_LDFLAGS="$LDFLAGS"
+  LDFLAGS="$LDFLAGS $pkg_cv_JANSSON_LIBS"
+  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+int
+main ()
+{
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_link "$LINENO"; then :
+
+else
+  pkg_failed=yes
+fi
+rm -f core conftest.err conftest.$ac_objext \
+    conftest$ac_exeext conftest.$ac_ext
+  LDFLAGS=$pkg_save_LDFLAGS
+fi
+
+
+
+if test $pkg_failed = yes; then
+        { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
+$as_echo "no" >&6; }
+
+if $PKG_CONFIG --atleast-pkgconfig-version 0.20; then
+        _pkg_short_errors_supported=yes
+else
+        _pkg_short_errors_supported=no
+fi
+        if test $_pkg_short_errors_supported = yes; then
+	        JANSSON_PKG_ERRORS=`$PKG_CONFIG --short-errors --print-errors --cflags --libs "jansson" 2>&1`
+        else
+	        JANSSON_PKG_ERRORS=`$PKG_CONFIG --print-errors --cflags --libs "jansson" 2>&1`
+        fi
+	# Put the nasty error message in config.log where it belongs
+	echo "$JANSSON_PKG_ERRORS" >&5
+
+
+	  as_fn_error $? "Cannot find jansson library" "$LINENO" 5
+
+elif test $pkg_failed = untried; then
+        { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
+$as_echo "no" >&6; }
+
+	  as_fn_error $? "Cannot find jansson library" "$LINENO" 5
+
+else
+	JANSSON_CFLAGS=$pkg_cv_JANSSON_CFLAGS
+	JANSSON_LIBS=$pkg_cv_JANSSON_LIBS
+        { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
+$as_echo "yes" >&6; }
+
+
+$as_echo "#define HAVE_JANSSON 1" >>confdefs.h
+
+
+
+
+fi
+
+else
+
+      as_fn_error $? "Cannot find pkg-config" "$LINENO" 5
+
+fi
+fi
+
 
 # Set the 'development' global.
 . $srcdir/../bfd/development.sh