[PATCH v3] Makerules: fix MAKEFLAGS assignment for upcoming make-4.4 [BZ# 29564]

[Sergei Trofimovich <slyich@gmail.com>]

make-4.4 will add long flags to MAKEFLAGS variable:

    * WARNING: Backward-incompatibility!
      Previously only simple (one-letter) options were added to the MAKEFLAGS
      variable that was visible while parsing makefiles.  Now, all options
      are available in MAKEFLAGS.

This causes locale builds to fail when long options are used:

    $ make --shuffle
    ...
    make  -C localedata install-locales
    make: invalid shuffle mode: '1662724426r'

The change fixes it by passing eash option via whitespace and dashes.
That way option is appended to both single-word form and whitespace
separated form.

While at it fixed --silent mode detection in $(MAKEFLAGS) by filtering
out --long-options. Otherwise options like --shuffle flag enable silent
mode unintentionally. $(silent-make) variable consolidates the checks.

CC: Paul Smith <psmith@gnu.org>
CC: Siddhesh Poyarekar <siddhesh@gotplt.org>
Signed-off-by: Sergei Trofimovich <slyich@gmail.com>
---
Change since v2:
- Used more robust '$(firstword' for suggested by Paul Smith.
Change since v1:
- Fixed $(MAKEFLAGS) introspection to avoid false positives on long
  options.
- Fixed 'Makefules' typo in the subject line.
 Makeconfig     | 18 +++++++++++++++++-
 Makerules      |  4 ++--
 elf/rtld-Rules |  2 +-
 3 files changed, 20 insertions(+), 4 deletions(-)

diff --git a/Makeconfig b/Makeconfig
index f8164a0025..842f49eb58 100644
--- a/Makeconfig
+++ b/Makeconfig
@@ -43,6 +43,22 @@ else
 $(error objdir must be defined by the build-directory Makefile)
 endif
 
+# Did we request 'make -s' run? "yes" or "no".
+# Starting from make-4.4 MAKEFLAGS now contains long
+# options like '--shuffle'. To detect presence of 's'
+# we pick first word with short options. Long options
+# are guaranteed to come after whitespace. We use '-'
+# prefix to always have a word before long options
+# even if no short options were passed.
+# Typical MAKEFLAGS values to watch for:
+#   "rs --shuffle=42" (silent)
+#   " --shuffle" (not silent)
+ifeq ($(findstring s, $(firstword -$(MAKEFLAGS))),)
+silent-make := no
+else
+silent-make := yes
+endif
+
 # Root of the sysdeps tree.
 sysdep_dir := $(..)sysdeps
 export sysdep_dir := $(sysdep_dir)
@@ -917,7 +933,7 @@ endif
 # umpteen zillion filenames along with it (we use `...' instead)
 # but we don't want this echoing done when the user has said
 # he doesn't want to see commands echoed by using -s.
-ifneq	"$(findstring s,$(MAKEFLAGS))" ""	# if -s
+ifeq ($(silent-make),yes)			# if -s
 +cmdecho	:= echo >/dev/null
 else						# not -s
 +cmdecho	:= echo
diff --git a/Makerules b/Makerules
index d1e139d03c..09c0cf8357 100644
--- a/Makerules
+++ b/Makerules
@@ -794,7 +794,7 @@ endif
 # Maximize efficiency by minimizing the number of rules.
 .SUFFIXES:	# Clear the suffix list.  We don't use suffix rules.
 # Don't define any builtin rules.
-MAKEFLAGS := $(MAKEFLAGS)r
+MAKEFLAGS := $(MAKEFLAGS) -r
 
 # Generic rule for making directories.
 %/:
@@ -811,7 +811,7 @@ MAKEFLAGS := $(MAKEFLAGS)r
 .PRECIOUS: $(foreach l,$(libtypes),$(patsubst %,$(common-objpfx)$l,c))
 \f
 # Use the verbose option of ar and tar when not running silently.
-ifeq	"$(findstring s,$(MAKEFLAGS))" ""	# if not -s
+ifeq ($(silent-make),no)			# if not -s
 verbose := v
 else	   					# -s
 verbose	:=
diff --git a/elf/rtld-Rules b/elf/rtld-Rules
index ca00dd1fe2..3c5e273f2b 100644
--- a/elf/rtld-Rules
+++ b/elf/rtld-Rules
@@ -52,7 +52,7 @@ $(objpfx)rtld-libc.a: $(foreach dir,$(rtld-subdirs),\
 	mv -f $@T $@
 
 # Use the verbose option of ar and tar when not running silently.
-ifeq	"$(findstring s,$(MAKEFLAGS))" ""	# if not -s
+ifeq ($(silent-make),no)			# if not -s
 verbose := v
 else						# -s
 verbose	:=
-- 
2.37.2