gccint: Language-dependent trees

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1 11.9 Language-dependent trees
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1 Front ends may wish to keep some state associated with various GENERIC
1 trees while parsing.  To support this, trees provide a set of flags that
1 may be used by the front end.  They are accessed using
1 'TREE_LANG_FLAG_n' where 'n' is currently 0 through 6.
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1  If necessary, a front end can use some language-dependent tree codes in
1 its GENERIC representation, so long as it provides a hook for converting
1 them to GIMPLE and doesn't expect them to work with any (hypothetical)
1 optimizers that run before the conversion to GIMPLE.  The intermediate
1 representation used while parsing C and C++ looks very little like
1 GENERIC, but the C and C++ gimplifier hooks are perfectly happy to take
1 it as input and spit out GIMPLE.
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