value_maybe_namespace_elt: Remove redundant call to lookup_static_symbol.
authorDoug Evans <xdje42@gmail.com>
Wed, 17 Dec 2014 08:30:29 +0000 (00:30 -0800)
committerDoug Evans <xdje42@gmail.com>
Wed, 17 Dec 2014 08:30:29 +0000 (00:30 -0800)
commit5e3c72e6b817a4d40a9ba551ed3c397098cdbfd4
treef1315b6208b29aa718e97c49790e8225438fbeb2
parentcc485e620197e6db42d942820d499b01794aeb00
value_maybe_namespace_elt: Remove redundant call to lookup_static_symbol.

Anytime you can remove a symbol lookup that loops over all objfiles
is A Good Thing.

The call to lookup_static_symbol in valops.c:value_maybe_namespace_elt
is redundant with this call in cp_lookup_nested_symbol:

/* Now search all static file-level symbols.  We have to do this
   for things like typedefs in the class.  We do not try to
   guess any imported namespace as even the fully specified
   namespace search is already not C++ compliant and more
   assumptions could make it too magic.  */

size = strlen (parent_name) + 2 + strlen (nested_name) + 1;
concatenated_name = alloca (size);
xsnprintf (concatenated_name, size, "%s::%s",
 parent_name, nested_name);
sym = lookup_static_symbol (concatenated_name, VAR_DOMAIN);
if (sym != NULL)
  return sym;

Earlier in value_maybe_namespace_elt we do this:

  sym = cp_lookup_symbol_namespace (namespace_name, name,
    get_selected_block (0), VAR_DOMAIN);

That sequence goes like:

value_maybe_namespace_elt
-> cp_lookup_symbol_namespace
-> cp_lookup_symbol_in_namespace
-> lookup_symbol_file
-> cp_lookup_nested_symbol
-> lookup_static_symbol

The call was added in commit 41f62f3939b1c69e68ef5652feb44fef90eb85c9.
https://sourceware.org/ml/gdb-patches/2010-06/msg00663.html
With a part 2 here:
https://sourceware.org/ml/gdb-patches/2010-06/msg00664.html

At the time the call to lookup_static_symbol (spelled
lookup_static_symbol_aux at the time) was needed.

However, this patch, 8dea366bbed7986295681c101dcfbd35aeb6dfc4,
https://sourceware.org/ml/gdb-patches/2012-11/msg00387.html
augmented lookup_symbol_file to call cp_lookup_nested_symbol
and introduced the redundancy.

It's kinda buried, so it's totally not unexpected that this happened.

gdb/ChangeLog:

* valops.c (value_maybe_namespace_elt): Remove redundant call to
lookup_static_symbol.
gdb/ChangeLog
gdb/valops.c