• Rasmus Villemoes's avatar
    Kbuild: fix # escaping in .cmd files for future Make · 9564a8cf
    Rasmus Villemoes authored and Masahiro Yamada's avatar Masahiro Yamada committed
    I tried building using a freshly built Make (4.2.1-69-g8a731d1), but
    already the objtool build broke with
    orc_dump.c: In function ‘orc_dump’:
    orc_dump.c:106:2: error: ‘elf_getshnum’ is deprecated [-Werror=deprecated-declarations]
      if (elf_getshdrnum(elf, &nr_sections)) {
    Turns out that with that new Make, the backslash was not removed, so cpp
    didn't see a #include directive, grep found nothing, and
    -DLIBELF_USE_DEPRECATED was wrongly put in CFLAGS.
    Now, that new Make behaviour is documented in their NEWS file:
      * WARNING: Backward-incompatibility!
        Number signs (#) appearing inside a macro reference or function invocation
        no longer introduce comments and should not be escaped with backslashes:
        thus a call such as:
          foo := $(shell echo '#')
        is legal.  Previously the number sign needed to be escaped, for example:
          foo := $(shell echo '\#')
        Now this latter will resolve to "\#".  If you want to write makefiles
        portable to both versions, assign the number sign to a variable:
          C := \#
          foo := $(shell echo '$C')
        This was claimed to be fixed in 3.81, but wasn't, for some reason.
        To detect this change search for 'nocomment' in the .FEATURES variable.
    This also fixes up the two make-cmd instances to replace # with $(pound)
    rather than with \#. There might very well be other places that need
    similar fixup in preparation for whatever future Make release contains
    the above change, but at least this builds an x86_64 defconfig with the
    new make.
    Link: https://bugzilla.kernel.org/show_bug.cgi?id=197847
    Cc: Randy Dunlap <rdunlap@infradead.org>
    Signed-off-by: default avatarRasmus Villemoes <linux@rasmusvillemoes.dk>
    Signed-off-by: Masahiro Yamada's avatarMasahiro Yamada <yamada.masahiro@socionext.com>
Kbuild.include 18.3 KB