Makefile doesn't permit incremental build

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1

I have a makefile from an example project, and it unfortunately forces a re-build when any single file in the project changes. I do not have a lot of experience with makefiles, so I'm not sure how to solve this problem.

The makefile defines the files to compile as a single variable SRCS like shown below. Of course, there are about 40 files in this list, in quite a few different directories.

SRCS = \
  ../../src/file1.c \
  ../../src/file2.c

Then later it defines the build rules for each .o file generated from each .c file.

$(OBJ_PATH)/%.o: $(SRCS)
    $(CC) $(FLAGS) $(filter %/$(subst .o,.c,$(notdir $@)), $(SRCS)) -o $@

According to make running with the -d option, all of the object files must be compiled again when a single .c file changes because $(SRCS) is defined as a dependency above.

How can I change this so if a single file changes only the 1 .o file must be compiled again?

asked 2 mins ago

davisoa

3,472

Makefile doesn't permit incremental build