Re: dangling pointer bug and proposed patch

[Eric Blake]

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According to Eric Blake on 6/3/2006 2:51 PM:
> I will apply it in a couple of days if I don't hear any feedback, at which
> point all known core dumps in 1.4.4 will be solved, and we can start
> thinking about releasing 1.4.5.
> 
> 2006-06-03  Eric Blake  <address@hidden>
> 
>       When changing macro definitions inside the arguments to the macro,
>       consistently preserve the old definition that was in effect before
>       argument collection, similar to the C pre-processor.
>       * NEWS: Document this change.
>       * doc/m4.texinfo (Macro Arguments, Undefine, Dumpdef): Document
>       this policy, and add tests that expose core dumps prior to this
>       patch.
>       * src/m4.h (struct symbol): New members to track when a symbol is
>       still in use after removal from the symbol table.
>       (SYMBOL_PENDING_EXPANSIONS, SYMBOL_DELETED): Define.
>       (free_symbol): Prototype.
>       * src/macro.c (expand_macro): Track pending expansions of a
>       symbol.  On completion, if a symbol is deleted and no longer
>       pending, free its memory.
>       * src/symtab.c (free_symbol): Export.  Don't free memory if symbol
>       is still in use.
>       (lookup_symbol) <SYMBOL_INSERT>: Create new entry when old entry
>       is still in use.
>       (lookup_symbol) <SYMBOL_DELETE, SYMBOL_POPDEF>: Mark entries still
>       in use as deleted and remove from the table without freeing
>       memory.
>       (symtab_debug, symtab_print_list): Fix for debugging.

FYI: I have applied this patch.  One more followon is coming.

- --
Life is short - so eat dessert first!

Eric Blake             address@hidden
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