A shocking number of LLSingleton subclasses had public constructors -- and in
several instances, were being explicitly instantiated independently of the
LLSingleton machinery. This breaks the new LLSingleton dependency-tracking
machinery. It seems only fair that if you say you want an LLSingleton, there
should only be ONE INSTANCE!
Introduce LLSINGLETON() and LLSINGLETON_EMPTY_CTOR() macros. These handle the
friend class LLSingleton<whatevah>;
and explicitly declare a private nullary constructor.
To try to enforce the LLSINGLETON() convention, introduce a new pure virtual
LLSingleton method you_must_use_LLSINGLETON_macro() which is, as you might
suspect, defined by the macro. If you declare an LLSingleton subclass without
using LLSINGLETON() or LLSINGLETON_EMPTY_CTOR() in the class body, you can't
instantiate the subclass for lack of a you_must_use_LLSINGLETON_macro()
implementation -- which will hopefully remind the coder.
Trawl through ALL LLSingleton subclass definitions, sprinkling in
LLSINGLETON() or LLSINGLETON_EMPTY_CTOR() as appropriate. Remove all explicit
constructor declarations, public or private, along with relevant 'friend class
LLSingleton<myself>' declarations. Where destructors are declared, move them
into private section as well. Where the constructor was inline but nontrivial,
move out of class body.
Fix several LLSingleton abuses revealed by making ctors/dtors private:
LLGlobalEconomy was both an LLSingleton and the base class for
LLRegionEconomy, a non-LLSingleton. (Therefore every LLRegionEconomy instance
contained another instance of the LLGlobalEconomy "singleton.") Extract
LLBaseEconomy; LLGlobalEconomy is now a trivial subclass of that.
LLRegionEconomy, as you might suspect, now derives from LLBaseEconomy.
LLToolGrab, an LLSingleton, was also explicitly instantiated by
LLToolCompGun's constructor. Extract LLToolGrabBase, explicitly instantiated,
with trivial subclass LLToolGrab, the LLSingleton instance.
(WARNING: LLToolGrabBase methods have an unnerving tendency to go after
LLToolGrab::getInstance(). I DO NOT KNOW what should be the relationship
between the instance in LLToolCompGun and the LLToolGrab singleton instance.)
LLGridManager declared a variant constructor accepting (const std::string&),
with the comment:
// initialize with an explicity grid file for testing.
As there is no evidence of this being called from anywhere, delete it.
LLChicletBar's constructor accepted an optional (const LLSD&). As the LLSD
parameter wasn't used, and as there is no evidence of it being passed from
anywhere, delete the parameter.
LLViewerWindow::shutdownViews() was checking LLNavigationBar::
instanceExists(), then deleting its getInstance() pointer -- leaving a
dangling LLSingleton instance pointer, a land mine if any subsequent code
should attempt to reference it. Use deleteSingleton() instead.
~LLAppViewer() was calling LLViewerEventRecorder::instance() and then
explicitly calling ~LLViewerEventRecorder() on that instance -- leaving the
LLSingleton instance pointer pointing to an allocated-but-destroyed instance.
Use deleteSingleton() instead.
Remove evil getIfExists() method, used by no one.
Remove evil destroyed() method, used in exactly three places -- one of which
is a test. Replace with equally evil instanceExists() method, which is used
EVERYWHERE -- sigh.
Instead of forbidding std::map<const std::type_info*, ...> outright (which
includes LLRegistry<const std::type_info*, ...> and LLRegistrySingleton<const
std::type_info*, ...>), try to make it work by specializing std::less<const
std::type_info*> to use std::type_info::before().
Make LLRegistryDefaultComparator<T> use std::less<T> so it can capitalize on
that specialization.
The changeset above touched every consumer of the two LLRegistrySingletons
originally defined with std::type_info* as keys. Those two
LLRegistrySingletons were changed to use const char* as keys, then all
consumers were changed to pass std::type_info::name() instead of the plain
std::type_info* pointer -- to deal with the observed fact that on Linux, a
given type might produce different std::type_info* pointers in different load
modules. Since then, Richard turned up the fascinating fact that at least some
implementations of gcc's std::type_info::before() method already accommodate
this peculiarity. It seems worth backing out the (dismayingly pervasive)
change to see if properly using std::type_info::before() as the map comparator
will work just as well, with conceptually simpler source code.
This backout is transitional: we don't expect things to build/run properly
until we've cherry-picked certain other pertinent changes.
Although LLRegistry and LLRegistrySingleton have always defined a COMPARATOR
template parameter, it wasn't used for the underlying map. Therefore every
type, including any pointer type, was being compared using std::less. This
happens to work most of the time -- but is tripping us up now.
Pass COMPARATOR to underlying std::map. Fix a couple minor bugs in
LLRegistryDefaultComparator (never before used!). Specialize for const char*.
Remove CompareTypeID and LLCompareTypeID because we now actively forbid using
LLRegistry<std::type_info*, ...>; remove only known reference
(LLWidgetNameRegistry definition).
Back out code that selects LLTypeInfoLookup for the underlying map
implementation when KEY = [const] std::type_info*, because LLTypeInfoLookup's
API is changing to become incompatible with std::map. Instead, fail with
STATIC_ASSERT when LLRegistry's KEY is [const] std::type_info*.
Fix all existing uses to use std::type_info::name() string instead.
In a number of places, the viewer uses a lookup based on std::type_info*. We
used to use std::map<std::type_info*, whatever>. But on Linux,
&typeid(SomeType) can produce different pointer values, depending on the
dynamic load module in which the code is executed. Introduce
LLTypeInfoLookup<T>, with an API that deliberately mimics
std::map<std::type_info*, T>. LLTypeInfoLookup::find() first tries an
efficient search for the specified std::type_info*. But if that fails, it
scans the underlying container for a match on the std::type_info::name()
string. If found, it caches the new std::type_info* to optimize subsequent
lookups with the same pointer.
Use LLTypeInfoLookup instead of std::map<std::type_info*, ...> in
llinitparam.h and llregistry.h.
Introduce LLSortedVector<KEY, VALUE>, a std::vector<std::pair<KEY, VALUE>>
maintained in sorted order with binary-search lookup. It presents a subset of
the std::map<KEY, VALUE> API.
Nat Goodspeed