what is the minimal version of make supported for building the kernel?

[Robert P. J. Day]

  another curiosity related to my current travels through the
initramfs code, i noticed this git commit from back in 2013:

$ git show 7ac1815683
commit 7ac181568342ec618d4da1ab03c2babcaa7ee84f
Author: Jan Beulich <JBeulich at suse.com>
Date:   Wed Dec 18 17:08:57 2013 -0800

    fix build with make 3.80

    According to Documentation/Changes, make 3.80 is still being supported
    for building the kernel, hence make files must not make (unconditional)
    use of features introduced only in newer versions.

    Commit 1bf49dd4be0b ("./Makefile: export initial ramdisk compression
    config option") however introduced "else ifeq" constructs which make
    3.80 doesn't understand.  Replace the logic there with more conventional
    (in the kernel build infrastructure) list constructs (except that the
    list here is intentionally limited to exactly one element).

    Signed-off-by: Jan Beulich <jbeulich at suse.com>
    Cc: P J P <ppandit at redhat.com>
    Signed-off-by: Andrew Morton <akpm at linux-foundation.org>
    Signed-off-by: Linus Torvalds <torvalds at linux-foundation.org>

diff --git a/Makefile b/Makefile
index 858a147..89cee86 100644
--- a/Makefile
+++ b/Makefile
@@ -732,19 +732,13 @@ export mod_strip_cmd
 # Select initial ramdisk compression format, default is gzip(1).
 # This shall be used by the dracut(8) tool while creating an
initramfs image.
 #
-INITRD_COMPRESS=gzip
-ifeq ($(CONFIG_RD_BZIP2), y)
-        INITRD_COMPRESS=bzip2
-else ifeq ($(CONFIG_RD_LZMA), y)
-        INITRD_COMPRESS=lzma
-else ifeq ($(CONFIG_RD_XZ), y)
-        INITRD_COMPRESS=xz
-else ifeq ($(CONFIG_RD_LZO), y)
-        INITRD_COMPRESS=lzo
-else ifeq ($(CONFIG_RD_LZ4), y)
-        INITRD_COMPRESS=lz4
-endif
-export INITRD_COMPRESS
+INITRD_COMPRESS-y                  := gzip
+INITRD_COMPRESS-$(CONFIG_RD_BZIP2) := bzip2
+INITRD_COMPRESS-$(CONFIG_RD_LZMA)  := lzma
+INITRD_COMPRESS-$(CONFIG_RD_XZ)    := xz
+INITRD_COMPRESS-$(CONFIG_RD_LZO)   := lzo
+INITRD_COMPRESS-$(CONFIG_RD_LZ4)   := lz4
+export INITRD_COMPRESS := $(INITRD_COMPRESS-y)

... etc etc ...

  now, Documentation/Changes currently does indeed state:

Current Minimal Requirements
============================
... snip ...
o  GNU make               3.80                    # make --version

but i did a quick grep to find:

  $ grep -r "else ifeq" *
  lib/raid6/test/Makefile:else ifeq ($(HAS_NEON),yes)
  $

so would that single test not violate the rule just described above?
is Documentation/Changes entirely up to date with respect to minimal
requirements?

rday

-- 

========================================================================
Robert P. J. Day                                 Ottawa, Ontario, CANADA
                        http://crashcourse.ca

Twitter:                                       http://twitter.com/rpjday
LinkedIn:                               http://ca.linkedin.com/in/rpjday
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