Re: [PATCH] Fix uninitialized use of variables.

Jim Blandy
2007-10-23T23:17:33Z

Carlos O'Donell <carlos at codesourcery.com> writes:
> In symtab.c (find_line_common) the variable *exact_match is not set if
> no match is found. Callers of find_line_common expect *exact_match to be
> set. The solution is to initialize *exact_match to zero, assuming an
> inexact match. In the case that we don't find a match in
> find_line_common, the statement `(best_index < 0 || !exact)' in
> symtab.c:2267 is true, instead of undefined. The comment is adjusted to
> indicate that one must look at another symtab if we failed to find a
> match `best_index < 0' or we found an inexact match `!exact.'

As far as the symtab.c change is concerned: the specification of
find_line_common is that *EXACT_MATCH is set only if the function
returns a match (a non-negative value). As far as I can see,
find_line_symtab doesn't actually use the value of 'exact' unless the
corresponding call to find_line_common returned a match. So the
warning looks spurious to me.

(I don't mind initializing 'exact' in find_line_symtab to placate the
compiler.)