from systemd: build: merge trivial changes back

These were trivial changes applied to systemd tree since the files were
synchronized:

  - change some comments
  - replace tab with space
  - fix typo

1 files changed, 15 insertions, 12 deletions

diff --git a/m4/attributes.m4 b/m4/attributes.m4
index 985a3ed..104f04c 100644
--- a/m4/attributes.m4
+++ b/m4/attributes.m4
@@ -33,18 +33,19 @@ dnl distribute a modified version of the Autoconf Macro, you may extend
 dnl this special exception to the GPL to apply to your modified version as
 dnl well.
 
-dnl Check if flag in a envvar is supported by compiler and append
-dnl "backup" variable
+dnl Check if FLAG in ENV-VAR is supported by compiler and append it
+dnl to WHERE-TO-APPEND variable
 dnl CC_CHECK_FLAG_APPEND([WHERE-TO-APPEND], [ENV-VAR], [FLAG])
+
 AC_DEFUN([CC_CHECK_FLAG_APPEND], [
   AC_CACHE_CHECK([if $CC supports flag $3 in envvar $2],
                  AS_TR_SH([cc_cv_$2_$3]),
-		 [eval "AS_TR_SH([cc_save_$2])='${$2}'"
-		  eval "AS_TR_SH([$2])='-Werror $3'"
-		  AC_COMPILE_IFELSE([AC_LANG_SOURCE([int a = 0; int main(void) { return a; } ])],
+                 [eval "AS_TR_SH([cc_save_$2])='${$2}'"
+                  eval "AS_TR_SH([$2])='-Werror $3'"
+                  AC_COMPILE_IFELSE([AC_LANG_SOURCE([int a = 0; int main(void) { return a; } ])],
                                     [eval "AS_TR_SH([cc_cv_$2_$3])='yes'"],
                                     [eval "AS_TR_SH([cc_cv_$2_$3])='no'"])
-		  eval "AS_TR_SH([$2])='$cc_save_$2'"])
+                  eval "AS_TR_SH([$2])='$cc_save_$2'"])
 
   AS_IF([eval test x$]AS_TR_SH([cc_cv_$2_$3])[ = xyes],
         [eval "$1='${$1} $3'"])
@@ -57,6 +58,8 @@ AC_DEFUN([CC_CHECK_FLAGS_APPEND], [
   done
 ])
 
+dnl Check if the flag is supported by linker (cacheable)
+dnl CC_CHECK_LDFLAGS([FLAG], [ACTION-IF-FOUND],[ACTION-IF-NOT-FOUND])
 
 
 dnl Check if the flag is supported by linker
@@ -101,13 +104,13 @@ AC_DEFUN([CC_NOUNDEFINED], [
      *-freebsd* | *-openbsd*) ;;
      *)
         dnl First of all check for the --no-undefined variant of GNU ld. This allows
-        dnl for a much more readable commandline, so that people can understand what
+        dnl for a much more readable command line, so that people can understand what
         dnl it does without going to look for what the heck -z defs does.
         for possible_flags in "-Wl,--no-undefined" "-Wl,-z,defs"; do
           CC_CHECK_LDFLAGS([$possible_flags], [LDFLAGS_NOUNDEFINED="$possible_flags"])
-	  break
+          break
         done
-	;;
+        ;;
   esac
 
   AC_SUBST([LDFLAGS_NOUNDEFINED])
@@ -243,8 +246,8 @@ AC_DEFUN([CC_FLAG_VISIBILITY], [
     [cc_flag_visibility_save_CFLAGS="$CFLAGS"
      CFLAGS="$CFLAGS $cc_cv_werror"
      CC_CHECK_CFLAGS_SILENT([-fvisibility=hidden],
-	cc_cv_flag_visibility='yes',
-	cc_cv_flag_visibility='no')
+        cc_cv_flag_visibility='yes',
+        cc_cv_flag_visibility='no')
      CFLAGS="$cc_flag_visibility_save_CFLAGS"])
 
   AS_IF([test "x$cc_cv_flag_visibility" = "xyes"],
@@ -274,7 +277,7 @@ AC_DEFUN([CC_CHECK_FUNC_BUILTIN], [
      $2],
     [AS_IF([test "x$3" = "x"], [AC_MSG_ERROR([*** builtin function not found: $1()])],
            [AC_DEFINE([HAVE_]m4_defn([UPNAME]), 0)
-	    $3])]
+            $3])]
   )
   m4_popdef([UPNAME])
 ])