example Makefile dependencies

[tkphd]

Commit a01bf6b removed the core MMSP includes as dependencies from the example Makefiles. This was erroneous in most cases: as a result of this commit, running make will not rebuild the binaries when the MMSP includes change, only when the example code changes. Proper usage defines a core variable containing the external files necessary to build an up-to-date binary, and including those files on the dependency line.

To clarify, using one of the anisotropic vector-valued grain growth codes as an example:

Current Makefile

graingrowth: graingrowth.cpp
    $(compiler) $(flags) $< -o $@ -lz

Former Makefile

core = $(incdir)/MMSP.hpp \
       $(incdir)/MMSP.main.hpp \
       $(incdir)/MMSP.utility.hpp \
       $(incdir)/MMSP.grid.hpp \
       $(incdir)/MMSP.vector.hpp
graingrowth: graingrowth.cpp anisotropy.hpp
    $(compiler) $(flags) $< -I$(core) -o $@ -lz

Correct Makefile

core = $(incdir)/MMSP.hpp \
       $(incdir)/MMSP.main.hpp \
       $(incdir)/MMSP.utility.h \
       $(incdir)/MMSP.utility.cpp \
       $(incdir)/MMSP.grid.h \
       $(incdir)/MMSP.grid.cpp \
       $(incdir)/MMSP.vector.h \
       $(incdir)/MMSP.vector.cpp
graingrowth: graingrowth.cpp graingrowth.hpp anisotropy.hpp $(core)
    $(compiler) $(flags) $< -o $@ -lz

Protip: $< denotes the first prerequisite, which in this example is graingrowth.cpp, not the whole slew of dependencies. The first item is critical, but order makes no difference for the remainder.

[tkphd]

Proper specification of dependencies in the Makefile and source files would resolve #37 as well.