[PATCH v3 0/4] Makefile: untangle bin-wrappers/% rule complexity

This series untangles the gnarly rule we use to generate bin-wrappers/%.

It's now complex because we generate it from 3x separate variables, and then end up having to do inline pattern matching to decide which value comes from where.

Instead, we can avoid squashing those values together, so we don't have to guess.

See[1] for the v2. This hopefully addresses all outstanding issues/points that were raised. An added 3/4 here makes the eventual 4/4 smaler.

1. https://lore.kernel.org/git/cover-v2-0.3-00000000000-20221026T143533Z-avarab@gmail.com/

Ævar Arnfjörð Bjarmason (4):
  Makefile: factor sed-powered '#!/bin/sh' munging into a variable
  Makefile: define "TEST_{PROGRAM,OBJS}" variables earlier
  Makefile: rename "test_bindir_programs" variable, pre-declare
  Makefile: simplify $(test_bindir_programs) rule by splitting it up

 Makefile | 70 +++++++++++++++++++++++++++++++++++++++++---------------
 1 file changed, 51 insertions(+), 19 deletions(-)

Range-diff against v2:
1:  fc6c5a6a8df = 1:  c9ce5b78a3a Makefile: factor sed-powered '#!/bin/sh' munging into a variable
2:  6dcb49f25c4 = 2:  b95c296b6de Makefile: define "TEST_{PROGRAM,OBJS}" variables earlier
-:  ----------- > 3:  fea93c45898 Makefile: rename "test_bindir_programs" variable, pre-declare
3:  400f487e30d ! 4:  0ff09495476 Makefile: simplify $(test_bindir_programs) rule by splitting it up
    @@ Commit message
         Which will show an empty diff, i.e. we've correctly dealt with the
         combination of $(SHELL_PATH), $(X) and these three variables here.
     
    -    This also fixes an issue with the "bin-wrappers/" scripts have never had properly declared
    -    dependency information, i.e. this has never worked:
    +    This also fixes an issue with the "bin-wrappers/" scripts have never
    +    had properly declared dependency information, i.e. this has never
    +    worked:
     
                 make clean &&
                 make bin-wrappers/git &&
    @@ Commit message
         Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
     
      ## Makefile ##
    -@@ Makefile: export TCL_PATH TCLTK_PATH
    - PTHREAD_LIBS = -lpthread
    - 
    - # Guard against environment variables
    -+BIN_WRAPPERS =
    - BUILTIN_OBJS =
    - BUILT_INS =
    - COMPAT_CFLAGS =
     @@ Makefile: GIT-PYTHON-VARS: FORCE
                  fi
      endif
      
    --test_bindir_programs := $(patsubst %,bin-wrappers/%,$(BINDIR_PROGRAMS_NEED_X) $(BINDIR_PROGRAMS_NO_X) $(TEST_PROGRAMS_NEED_X))
    +-BIN_WRAPPERS = $(patsubst %,bin-wrappers/%,$(BINDIR_PROGRAMS_NEED_X) $(BINDIR_PROGRAMS_NO_X) $(TEST_PROGRAMS_NEED_X))
     +define cmd_munge_bin_wrappers_script
     +sed \
     +	-e $(call cmd_munge_script_sed_shell_path_arg) \
    @@ Makefile: GIT-PYTHON-VARS: FORCE
     +	chmod +x $@
     +endef
      
    --all:: $(test_bindir_programs)
    +-all:: $(BIN_WRAPPERS)
     +define bin_wrappers_template
     +
    -+## bin_wrappers_template
    -+# 1 = $(1)
    -+# 2 = $(2)
    -+# 3 = $(3)
    -+# 4 = $(4)
    ++### bin_wrappers_template; Parameters:
    ++## E.g. "BINDIR_PROGRAMS_NEED_X": Variable reference
    ++# 1='$(1)'
    ++## E.g. "$(@F)": Passed as $$(1)) to "cmd_munge_bin_wrappers_script"
    ++# 2='$(2)'
    ++## E.g. "" or "t/helper": Directory prefix for the wrapped binary
    ++# 3='$(3)'
    ++## E.g. "" or "$$X": If $$X: wrapped binary needs X=.exe (for Windows)
    ++# 4='$(4)'
     +BW_$(1) = $$($(1):%=bin-wrappers/%)
     +BIN_WRAPPERS += $$(BW_$(1))
    -+all:: $$(BW_$(1))
     +$$(BW_$(1)): bin-wrappers/% : $(3)%$(4)
     +$$(BW_$(1)): wrap-for-bin.sh
     +	$$(call mkdir_p_parent_template)
    @@ Makefile: GIT-PYTHON-VARS: FORCE
      
      # GNU make supports exporting all variables by "export" without parameters.
      # However, the environment gets quite big, and some programs have problems
    -@@ Makefile: OTHER_PROGRAMS += $(shell echo *.dll t/helper/*.dll)
    - endif
    - 
    - artifacts-tar:: $(ALL_COMMANDS_TO_INSTALL) $(SCRIPT_LIB) $(OTHER_PROGRAMS) \
    --		GIT-BUILD-OPTIONS $(TEST_PROGRAMS) $(test_bindir_programs) \
    -+		GIT-BUILD-OPTIONS $(TEST_PROGRAMS) $(BIN_WRAPPERS) \
    - 		$(MOFILES)
    - 	$(QUIET_SUBDIR0)templates $(QUIET_SUBDIR1) \
    - 		SHELL_PATH='$(SHELL_PATH_SQ)' PERL_PATH='$(PERL_PATH_SQ)'