Geek asks and answers

How do I specify the order in which the Makefile target is created without any physical dependencies?

I was working on a C ++ project that references a .so (dynamic library) file. Suppose I have a target PROG that should reference a.so, and a.so is also built by me, as indicated in the following Makefile.

PROG_SRCS = prog.cpp
PROG_OBJS = $(PROG_SRCS: %.cpp:%.o)

all: PROG
PROG: $(PROG_OBJS) liba.so
    $(LINK.cpp) -o $@ $(PROG_OBJS) -la

LIBA_SRCS = liba/a.cpp
LIBA_OBJS = $(LIBA_SRCS: %.cpp:%.o)

liba.so: $(LIBA_OBJS)
    $(LINK.cpp) -shared -Wl.-soname,$@ -o $@ $^

I used auto-dependency generation to get .cpp files to get their own dependency on .h files. And prog.cpp includes ah

But in this way, as soon as I change a.cpp, liba.so will be redone, then PROG will be a remake (relink), which I do not want. I am just modifying the liba.so implementation, but not any interface definitions. PROG should just redo after changing ah

, a.so , PROG, a.so PROG.

Makefile - , , ( ).

ORDER = /tmp/.ORDER

all: PROG
PROG: $(PROG_OBJS) $(ORDER)
    $(LINK.cpp) -shared -Wl,-soname,$@ -o $@ $(PROG_OBJS) -la

$(ORDER): liba.so
    test -e $@ || touch $@

, , liba.so , $(ORDER) . , .

​​ - , . tmp.

+3
1

GNU make, - . , , .

+2

More articles:


All Articles