automake: Canonicalization

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1 3.5 How derived variables are named
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1 Sometimes a Makefile variable name is derived from some text the
1 maintainer supplies.  For instance, a program name listed in ‘_PROGRAMS’
1 is rewritten into the name of a ‘_SOURCES’ variable.  In cases like
1 this, Automake canonicalizes the text, so that program names and the
1 like do not have to follow Makefile variable naming rules.  All
1 characters in the name except for letters, numbers, the strudel (@), and
1 the underscore are turned into underscores when making variable
1 references.
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1    For example, if your program is named ‘sniff-glue’, the derived
1 variable name would be ‘sniff_glue_SOURCES’, not ‘sniff-glue_SOURCES’.
1 Similarly the sources for a library named ‘libmumble++.a’ should be
1 listed in the ‘libmumble___a_SOURCES’ variable.
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1    The strudel is an addition, to make the use of Autoconf substitutions
1 in variable names less obfuscating.
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