> I want to compile objects in order of the writting
Just because, today, make happens to pick nearly what you want it to do without
being told about your ordering constraint, doesn't mean that you should rely on
it continuing to do so. You should teach make about that order. You could
contrive a function to $(eval) your y.o z.o x.o list into a chain of pairwise
dependencies:
z.o: y.o
x.o: z.o
Like this:
martind@sirius:~/tmp/ljh-2022-08-11$ cat Makefile
objs = y.o z.o x.o
space = $(subst :,,: :)
makeDependency = $(eval $(lastword $(1)): $(firstword $(1)))
$(foreach pair,$(filter-out guard@@% %@@guard,$(join guard $(objs),$(addprefix
@@,$(objs) guard))),$(call makeDependency,$(subst @@,$(space),$(pair))))
martind@sirius:~/tmp/ljh-2022-08-11$ make -p | grep '[xyz]\.o: [xyz].o'
make: *** No rule to make target 'y.o', needed by 'z.o'. Stop.
z.o: y.o
x.o: z.o
martind@sirius:~/tmp/ljh-2022-08-11$
________________________________
From: Bug-make <bug-make-bounces+martin.dorey=hds....@gnu.org> on behalf of ljh
<l...@qq.com>
Sent: Thursday, August 11, 2022 01:56
To: Philip Guenther <guent...@gmail.com>
Cc: psmith <psm...@gnu.org>; bug-make <bug-make@gnu.org>
Subject: 回复： Implicit rule for linking multiple object files
***** EXTERNAL EMAIL *****
Thanks Philip,
I want to compile objects in order of the writting: y.o z.o x.o .
The order of compiling x.o are different in below three cases.
I don't understand the difference.
x : y.o z.o x.o # compiles x.o last
$(CC) $^ -o $@ # with recipe
x : y.o z.o # compiles x.o last
x : y.o z.o x.o # compiles x.o first
My purpose is to keep my Makefile simple. With the patsubst function in
Makefile, I just put Makefile with my source files and need to do nothing.
It just compiles. But this is gone if the order of compiling matters.
x : $(patsubst %.c,%.o,$(wildcard *.c))
Thanks
---
# My Minimal Makefile for C, C++
# build shared library with -fPIC, -shared
CFLAGS = -Wall -Wextra -g # -O3 -fPIC # CXXFLAGS for .cpp
LDFLAGS = # -L../hello # -shared
LDLIBS = # -lhello
CPPFLAGS = -MMD -MP # -I../hello
#CC = $(CXX) # link with CXX for .cpp
# target name is basename of one of the source files
main : $(patsubst %.c,%.o,$(wildcard *.c)) # .cpp
-include *.d
clean : ; -rm -fr *.o *.d
.PHONY : clean
