using if statement in Makefile.am(automake)

Question

I know that for Makefile we can write the following bloc

ifneq ($(MYAPP_REVISION)_,_)
ifneq ($(MYAPP_REVISION),exported)
    myapp_CFLAGS+=-DMYAPP_REVISION=\"$(MYAPP_REVISION)\"
    myapp_LDFLAGS+=-DMYAPP_REVISION=\"$(MYAPP_REVISION)\"
endif
endif

But if write this bloc in the makefile.am (autoconf) I will get the build not working.

Any idea about writing the equivalent of this bloc in the makefile.am ?

Answer 1

您必须在源代码中查找生成的输出并引用M4语法。