On Wed, Nov 30, 2022 at 2:10 AM Dmitry Goncharov <dgoncharov@xxxxxxxxxxxx> wrote: > > Port silent mode detection to the future (post make-4.4) versions of gnu make. > > Makefile contains the following piece of make code to detect if option -s is > specified on the command line. > > ifneq ($(findstring s,$(filter-out --%,$(MAKEFLAGS))),) > > > This code is executed by make at parse time and assumes that MAKEFLAGS > does not contain command line variable definitions. > Currently if the user defines a=s on the command line, then at build only > time MAKEFLAGS contains " -- a=s". > However, starting with commit dc2d963989b96161472b2cd38cef5d1f4851ea34 > MAKEFLAGS contains command line definitions at both parse time and > build time. > > This '-s' detection code then confuses a command line variable > definition which contains letter 's' with option -s. > > E.g. > $ # old make > $ make net/wireless/ocb.o a=s > CALL scripts/checksyscalls.sh > DESCEND objtool > $ # this a new make which defines makeflags at parse time > $ ~/src/gmake/make/l64/make net/wireless/ocb.o a=s > $ > > We can see here that the letter 's' from 'a=s' was confused with -s. > > This patch checks for presence of -s using a method recommended by the > make manual here > https://www.gnu.org/software/make/manual/make.html#Testing-Flags. The GNU Make manual is written with the latest Make version in mind. "Recall that MAKEFLAGS will put all single-letter options (such as ‘-t’) into the first word, and that word will be empty if no single-letter options were given." This statement is not true for GNU Make 3.82, which the kbuild supports. $ git show 6f0fa58 commit 6f0fa58e459642b16901521cc58ac474b787ec5b Author: Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx> Date: Fri May 19 20:42:30 2017 +0900 kbuild: simplify silent build (-s) detection [snip] Test cases: [1] command line input: make --silent -> MAKEFLAGS for Make 3.8x: s -> MAKEFLAGS for Make 4.x : s [2] command line input: make -srR -> MAKEFLAGS for Make 3.8x: sRr -> MAKEFLAGS for Make 4.x : rRs [3] command line input: make -s -rR --warn-undefined-variables -> MAKEFLAGS for Make 3.8x: --warn-undefined-variables -sRr -> MAKEFLAGS for Make 4.x : rRs --warn-undefined-variables As this commit description says, Make 3.8x puts long options before the collection of single letter options. So, this patch does not work for Make 3.82. -- Best Regards Masahiro Yamada
