Makefile cheatlist (assembled by Veselin Georgiev)
for GNU make only!
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1. SOMEVAR = SOMETHING vs SOMEVAR := SOMETHING

  X = Y is recursive. Every time X is met during parsing, it is reevaluated. Useful if it contains
    other references.
  X := Y is simply-evaluated. Computed only once. Useful for getting shell values like
    OS := $(shell uname -s)

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2. Automatic variables: $@ vs $<
   $@ is the target. $< is the source. As in:
   
foo.o: foo.c
	$(CC) -o $@ $<

   which expands to "cc -o foo.o foo.c".

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3. Compile a bunch of .cpp's:

%.o: %.cpp $(HEADERS)
	$(CXX) $(INCLUDES) -o $@ $<


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4. Conditional statements:

ifeq ($(OS), Linux)
  CXX = g++
  ...
else
  CXX = cl
endif

note there's no quotes around the second argument.

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5. SUFFIXES

.SUFFIXES: .pdf .bat

will add .pdf and .bat to the list of default suffixes. To empty the list use

.SUFFIXES:
.SUFFIXES: .pdf .bat

This way, ONLY .pdf and .bat will be present in the suffix list.
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6. Doing compilation quietly (not showing which commands are executed):

.SILENT:

Alternatively, add `@' before commands.
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7. PHONY

all targets, which do not produce a real output file (all, clean, etc...) are
listed in phony:

.PHONY: all clean

I have yet to wait seeing an example where this line was somehow useful, but
nevertheless, here you have it.