Re: Pattern Rules Question

[Guy Harrison]

cppaddict wrote:

> Hi,
> 
> A simple question about pattern rules.  The relevant part of my
> Makefile looks like this:
> 
> <Makefile>
> 
> OBJS=Main.obj WinDirectory.obj
> 
> all: $(OBJS)
> $(CXX) $(OBJS)
> 
> %.obj : %.cpp %.h
> $(CXX) -c $(CPPFLAGS) $<
> 
> </Makefile>
> 
> This works as expected when I update either WinDirectory.h or
> WinDirectory.cpp -- make recompiles WinDirectory.cpp and then links
> WinDirectory.obj and Main.obj.  However, if I update Main.cpp, make
> will not recompile it.  In fact, make doesn't do anything.  I'm
> guessing this is because Main.h does not exist.
> 
> In any case, how can alter my Makefile to get it to process updates to
> Main.cpp too (ie, to correctly process .cpp files that don't have a
> sister .h file)?

Have a look at the -M options to gcc. They can generate dependancy
information for you. Strictly the rest's offtopic so only a hint...

[stuff]
NAM             =c
ITM             =foo bar
OBJ             =$(ITM:%=%.obj)
DEP             =$(ITM:%=%.d)
EXE             =$(NAM).exe

%.obj : %.cpp
                $(CXX) -MMD -c -o $@ $(CPPFLAGS) $(CXXFLAGS) $<
[stuff]
-include        $(DEP)

-- 
Guy Harrison