[06/32] cpp macros

Jeff Law law@redhat.com
Mon Nov 23 21:13:14 GMT 2020



On 11/3/20 2:14 PM, Nathan Sidwell wrote:
>
> Header units can provide macros to an importer.  For efficiency that
> is done lazily.  When we import a header unit we mark the identifers
> it defines as significant.  It's only when we need the macro
> definition (including in #ifdef &| defined (X) processing) that we
> resolve the macro.  We already had lazy (builtin) macros.  This
> extends it to deferred macros.  Each deferred macro has an index the
> resolver can use.   on an LP64 host that index does not inlarge the
> node structure.
>
> As a macro can be undefined by this mechanism, the users of this
> deferred interface must be prepared to handle 'not a macro after all'
>
>
>
>
> 06-cpp-macro.diff
>
>
OK with the usual ChangeLog note.
jeff



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