autoconf: Why GNU M4
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1 20.2 Why Require GNU M4?
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1 Why does Autoconf require GNU M4?
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1 Many M4 implementations have hard-coded limitations on the size and
1 number of macros that Autoconf exceeds. They also lack several builtin
1 macros that it would be difficult to get along without in a
1 sophisticated application like Autoconf, including:
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1 m4_builtin
1 m4_indir
1 m4_bpatsubst
1 __file__
1 __line__
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1 Autoconf requires version 1.4.6 or later of GNU M4.
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1 Since only software maintainers need to use Autoconf, and since GNU
1 M4 is simple to configure and install, it seems reasonable to require
1 GNU M4 to be installed also. Many maintainers of GNU and other free
1 software already have most of the GNU utilities installed, since they
1 prefer them.
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