Question

I have this C++ project which compiles using a Makefile, and sometimes when (my guess) there are some missing includes, I get a cryptic “error 2” message and the make process stops.
I suspect the missing includes because this is the third times it happens when I included a non-existent header file.

It looks like this:

---- Build tmp/foo.o ----
---- Build tmp/bar.o ----
---- Build tmp/toto.o ----
---- Build tmp/tata.o ----
make: *** [build_Project] Error 2

This is driving me nuts, because even using verbose commands (where each g++ invocation is showed), I can’t see anything.
I expected the guy to throw up some erroneous messages like “can’t find header X” or “undefined reference to Y“, but there’s nothing.

My compiling options for gcc are -O0 -Wall -Werror -Wno-write-strings -fno-rtti -fno-exceptions, if this helps.

Ah, and we use the Makefile trick of including dependencies:

ifneq ($(strip $(DEPENDS)),)
ifneq ($(MAKECMDGOALS),clean)
-include $(DEPENDS)
endif
endif

( see here and here for more information )

Although this is documented stuff, I suspect my problem has something to do with this dependencies inclusion.

If you already stumbled on this issue, feel free to comment on this…

Thanks in advance.

edit:
Okay, after a bit of playing, suppressing the - in front of -include $(DEPENDS) gives me some more info (the makefile does stop on the missing included file).

make[1]: *** No rule to make target « foo.h », necessary for « tmp/bar.d ». Stop.

Now the drawback is that when I launch make for the first time, I get a missing bar.d file message for each dependency file that should be included (which was why we put the - in the first place).
Any solution?

Answer 1

Ok my edit solved the problem: placing a dash - in front of include hides the error messages coming from the dependency generation.

Note for later: don’t try to outsmart Make.