1 # Copyright (C) 2012 W. Trevor King
3 # This program is free software: you can redistribute it and/or modify
4 # it under the terms of the GNU General Public License as published by
5 # the Free Software Foundation, either version 3 of the License, or
6 # (at your option) any later version.
8 # This program is distributed in the hope that it will be useful,
9 # but WITHOUT ANY WARRANTY; without even the implied warranty of
10 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 # GNU General Public License for more details.
13 # You should have received a copy of the GNU General Public License
14 # along with this program. If not, see <http://www.gnu.org/licenses/>.
16 # Declare variables describing package information.
17 # http://www.gnu.org/software/make/manual/html_node/Setting.html
18 # The $(...) syntax references a variable's value.
19 # http://www.gnu.org/software/make/manual/html_node/Reference.html
20 # You can override variables from the command line. For example
21 # $ make VERSION=2 dist
22 # will generate phys405-hw0-2.tar.gz
26 RELEASE = $(COURSE)-$(PACKAGE)-$(VERSION)
27 RUN_PROGRAM = hello_world
28 C_PROGRAMS = hello_world
29 CXX_PROGRAMS = goodbye_world
30 PROGRAMS = $(C_PROGRAMS) $(CXX_PROGRAMS)
32 # Define the source files that will be distributed in the tarball
33 SOURCE = *.c *.cpp *.h COPYING Makefile README
35 # Define a list of object files needed to link PROGRAM. We're setting
36 # things up here so that a program % depends on the object file %.o.
37 # For details on `foreach` and `eval`, see
38 # http://www.gnu.org/software/make/manual/html_node/Foreach-Function.html
39 # http://www.gnu.org/software/make/manual/html_node/Eval-Function.html
40 $(foreach PROGRAM, $(PROGRAMS), $(eval $(PROGRAM)_OBJECTS = $(PROGRAM).o))
42 # You can override a paricular case here with something like:
43 #hello_world_OBJECTS = hello_world.o utility_code.o
45 # You may want to link agains external libraries. For example, to
46 # link against the system math library, use.
47 # hello_world_LIBS = -lm
48 $(foreach PROGRAM, $(PROGRAMS), $(eval $(PROGRAM)_LIBS =))
50 # Define useful programs (this makes it easy to swap in alternates)
57 # Declare targets that do not generate files of the same name.
58 # http://www.gnu.org/software/make/manual/html_node/Phony-Targets.html
59 .PHONY: all help clean dist run print- printvars
61 # target: all - the default target
64 # target: help - display callable targets
65 # Use `grep` to search this file for target comments
67 $(GREP) '^# target:' [Mm]akefile
69 # target: clean - remove automatically generated files
71 $(RM) -rf $(PROGRAMS) *.o $(RELEASE)*
73 # target: dist - generate a tarball packaging the source
74 # Here, we move the source into a temporary release directory, tar the
75 # release directory, and remove the release directory.
78 $(CP) -r $(SOURCE) $(RELEASE)
79 $(TAR) -czf $(RELEASE).tar.gz $(RELEASE)
82 # target: hello_world - compile the hello_world program
83 # Use GCC to link the program from object files.
84 # For an explanation of the
85 # targets ...: target-pattern: prereq-patterns ...
87 # http://www.gnu.org/software/make/manual/html_node/Static-Usage.html
88 # For an explanation of $@, $^ and other special variables, see
89 # http://www.gnu.org/software/make/manual/html_node/Automatic-Variables.html
90 # For an explanation of .SECONDEXPANSION, see
91 # http://www.gnu.org/software/make/manual/html_node/Secondary-Expansion.html
92 # `$$` escapes make-variable expansion for the first pass through the
94 # http://www.gnu.org/software/make/manual/html_node/Variables-in-Recipes.html
96 # What's going on here? During the read-in phase, Make expands the
98 # hello_world goodbye_world: % : $($(@)_OBJECTS)
99 # Because we're using .SECONDEXPANSION, Make expands the prerequisites
100 # again during the target-update phase. If we're building
101 # hello_world, $(@) will expand to hello_world, and we'll have
102 # hello_world goodbye_world: hello_world : $(hello_world_OBJECTS)
103 # as the variable expansion continues, we end up with
104 # hello_world goodbye_world: hello_world : hello_world.o
105 # which is the final rule used to determine the prerequisites.
107 # The recipe expands to
108 # cc -o hello_world hello_world.o $(hello_world_LIBS)
109 # which expands to (if hello_world_LIBS was set to `-lm`)
110 # cc -o hello_world hello_world.o -lm
112 # Striking the right balance between "everything handled
113 # automatically" (i.e. "complicated") and "everything handled
114 # manually" (i.e. tedious) is difficult, and maybe this rule crosses
115 # the line. The simpler alternative would be to define your own
116 # prerequisites for each program you wish to compile, and you're
117 # certainly allowed to go that route if you wish.
119 $(C_PROGRAMS): % : $$($$(@)_OBJECTS)
120 $(CC) $(LDFLAGS) -o $@ $^ $($(@)_LIBS)
123 $(CXX_PROGRAMS): % : $$($$(*)_OBJECTS)
124 $(CXX) $(LDFLAGS) -o $@ $^ $($(@)_LIBS)
126 # target: run - use the program for its intended purpose
127 # Here we just execute RUN_PROGRAM, but you could also use something
129 # run: $(RUN_PROGRAM) plot.gp
130 # ./$(RUN_PROGRAM) > data
132 # where plot.gp was a gnuplot script for plotting data generated by
137 # Matching rule for compiling object files from C++ source
138 # There is an implicit rule for this in GNU make
139 # http://www.gnu.org/software/make/manual/html_node/Catalogue-of-Rules.html
140 # but I redefine it here for clarity.
142 # CXX and CXXFLAGS have defaults defined by make
143 # http://www.gnu.org/software/make/manual/html_node/Implicit-Variables.html
144 # but they can also be come from the environment
145 # http://www.gnu.org/software/make/manual/html_node/Environment.html
147 # $ make CXX=/usr/local/bin/g++ CXXFLAGS=-Wall
149 $(CXX) $(CXXFLAGS) -c $<
151 # Matching rule for compiling object files from C source
152 # The comments from the C++ rule above also apply here
154 $(CC) $(CFLAGS) -c $<
156 # target: print-% - display a variable value (e.g. print-PROGRAMS)
157 # Take some of the mystery out of variable manipulation. For example,
158 # $ make print-hello_world_OBJECTS
159 # The `@` suppresses recipe echoing. See
160 # http://www.gnu.org/software/make/manual/html_node/Echoing.html
161 # The `info` function acts like the shell `echo` command. See
162 # http://www.gnu.org/software/make/manual/html_node/Make-Control-Functions.html
163 # For an explanation of $* and other special variables, see
164 # http://www.gnu.org/software/make/manual/html_node/Automatic-Variables.html
168 # target: printvars - display all non-default variables
169 # .VARIBALES holds a list of all global variables. See
170 # http://www.gnu.org/software/make/manual/html_node/Special-Variables.html
171 # The functions---`sort`, `if`, `filter-out`, `origin`, `warning`, and
172 # `value`--- are discussed, respectively, here:
173 # http://www.gnu.org/software/make/manual/html_node/Text-Functions.html#index-sort-580
174 # http://www.gnu.org/software/make/manual/html_node/Conditional-Functions.html
175 # http://www.gnu.org/software/make/manual/html_node/Text-Functions.html#index-filter_002dout-577
176 # http://www.gnu.org/software/make/manual/html_node/Origin-Function.html
177 # http://www.gnu.org/software/make/manual/html_node/Value-Function.html
180 $(sort $(.VARIABLES)), \
182 $(filter-out environment default automatic, \
184 $(info $V=$($V) (origin: $(origin $V), value: $(value $V))) \