CODEWITHSUNDEEP
c++makefile
Vivek Goel
Vivek Goel

Reputation: 24160

Make file header file dependency

I want to add header file dependency in make file

I written rule 

 ${OBJECTDIR}/%.o: %.cc %.h
 gcc  $(WarningLevel)  $(CFLAGS) $(INCLUDES)  -c  -o $@  $^

but there are two error

One for .cc file which don't have any .h files . It will give no rule to make. Second one is the object file build by rule give error at linking 

file format not recognized; treating as linker script

how can I achieve that ? (source file should be compile if header file is got modified )

Upvotes: 2

Views: 3576

Answers (2)

Jack Kelly
Jack Kelly

Reputation: 18667

First of all, you haven't shown us your link command. Secondly, you shouldn't be using $^ here. $^ expands to a list of all dependencies (here, the .c and the .h), but we only want to compile the .c file. Use $<, which expands only to the name of the first dependency:

${OBJECTDIR}/%.o: %.c %.h
        gcc $(WarningLevel) $(CFLAGS) $(INCLUDES) -c -o $@ $<

Upvotes: 2

J T
J T

Reputation: 5156

You need to provide a rule for the header file dependency you listed:

%.h:
    echo This is my build target for header files.

Make won't actually do anything with the %.h files, but atleast you're telling it to watch for file changes (which then cause the .o files to need recompilation).

Upvotes: 1

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